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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 79, 80, 85, 86, 600, 1036, 1037, 1039, 1042, 1048, 1054, 1065, and 1066

[EPA–HQ–OAR–2011–0135; FRL 9906-86-OAR]

RIN 2060-AQ86

Control of Air Pollution from Motor Vehicles: Tier 3 Motor Vehicle Emission and 

Fuel Standards

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final Rule.

SUMMARY: This action establishes more stringent vehicle emissions standards and will 

reduce the sulfur content of gasoline beginning in 2017, as part of a systems approach to 

addressing the impacts of motor vehicles and fuels on air quality and public health. The 

gasoline sulfur standard will make emission control systems more effective for both 

existing and new vehicles, and will enable more stringent vehicle emissions standards. 

The vehicle standards will reduce both tailpipe and evaporative emissions from passenger 

cars, light-duty trucks, medium-duty passenger vehicles, and some heavy-duty vehicles. 

This will result in significant reductions in pollutants such as ozone, particulate matter, 

and air toxics across the country and help state and local agencies in their efforts to attain 

and maintain health-based National Ambient Air Quality Standards. Motor vehicles are 

an important source of exposure to air pollution both regionally and near roads. These 

vehicle standards are intended to harmonize with California’s Low Emission Vehicle 

program, thus creating a federal vehicle emissions program that will allow automakers to 

sell the same vehicles in all 50 states. The vehicle standards will be implemented over 

the same timeframe as the greenhouse gas/fuel efficiency standards for light-duty

vehicles (promulgated by EPA and the National Highway Safety Administration in 

2012), as part of a comprehensive approach toward regulating emissions from motor 

vehicles. 

DATES: This final rule is effective on [Insert date 60 days after publication in the 

Federal Register]. The incorporation by reference of certain publications listed in this 

regulation is approved by the Director of the Federal Register as of [Insert date 60 days 

after publication in the Federal Register].

ADDRESSES: EPA has established a docket for this action under Docket ID No. EPA–

HQ–OAR–2011–0135. All documents in the docket are listed on the 

www.regulations.gov web site. Although listed in the index, some information is not 

publicly available, e.g., CBI or other information whose disclosure is restricted by statute. 

Certain other material, such as copyrighted material, is not placed on the Internet and will 

be publicly available only in hard copy form. Publicly available docket materials are 
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available either electronically in www.regulations.gov or in hard copy at the Air and 

Radiation Docket and Information Center, EPA/DC, EPA West, Room 3334, 1301 

Constitution Ave., NW, Washington, DC. The Public Reading Room is open from 8:30 

a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone 

number for the Public Reading Room is (202) 566-1744, and the telephone number for 

the Air Docket is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT: JoNell Iffland, Office of 

Transportation and Air Quality, Assessment and Standards Division (ASD), 

Environmental Protection Agency, 2000 Traverwood Drive, Ann Arbor MI 48105; 

Telephone number: (734) 214-4454; Fax number: (734) 214-4816; E-mail address: 

iffland.jonell@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

Entities potentially affected by this rule include gasoline refiners and importers, 

ethanol producers, ethanol denaturant producers, butane and pentane producers, gasoline 

additive manufacturers, transmix processors, terminals and fuel distributors, light-duty

vehicle manufacturers, independent commercial importers, alternative fuel converters, 

and manufacturers and converters of vehicles between 8,500 and 14,000 lbs gross vehicle 

weight rating (GVWR). 

Potentially regulated categories include:

Category NAICSa Code SIC

b Code Examples of Potentially Affected Entities

Industry 324110 2911 Petroleum refineries (including importers)

Industry 325110 2869 Butane and pentane manufacturers

Industry 325193 2869 Ethyl alcohol manufacturing

Industry 324110,

211112

2911,

1321

Ethanol denaturant manufacturers

Industry 211112 1321 Natural gas liquids extraction and fractionation

Industry 325199 2869 Other basic organic chemical manufacturing

Industry 486910 4613 Natural gas liquids pipelines, refined petroleum 

products pipelines

Industry 424690 5169 Chemical and allied products merchant 

wholesalers

Industry 325199 2869 Manufacturers of gasoline additives

Industry 424710 5171 Petroleum bulk stations and terminals.

Industry 493190 4226 Other warehousing and storage- bulk petroleum 

storage

Industry 336111, 3711 Light-duty vehicle and light-duty truck 
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336112 manufacturers

Industry 811111, 

811112, 

811198

7538, 

7533, 

7534 Independent commercial importers

Industry 335312,

336312,

336322,

336399,

811198

3621, 

3714, 

3519, 

3599, 

7534 Alternative fuel converters

Industry 333618,

336120,

336211,

336312

3699, 

3711, 

3713, 

3714

On-highway heavy-duty engine & vehicle 

(>8,500 lbs GVWR) manufacturers

a North American Industry Classification System (NAICS).

b

Standard Industrial Classification (SIC).

This table is not intended to be exhaustive, but rather provides a guide for readers

regarding entities likely to be regulated by this action. This table lists the types of entities 

that EPA is now aware could potentially be regulated by this action. Other types of 

entities not listed in the table could also be regulated. To determine whether your 

activities are regulated by this action, you should carefully examine the applicability

criteria in 40 CFR parts 79, 80, 85, 86, 600, 1036, 1065, and 1066 and the referenced 

regulations. If you have any questions regarding the applicability of this action to a 

particular entity, consult the person listed in the preceding FOR FURTHER 

INFORMATION CONTACT section.

B. Did EPA Conduct a Peer Review before Issuing this Action?

This regulatory action was supported by influential scientific information. 

Therefore, EPA conducted peer reviews in accordance with OMB’s Final Information 

Quality Bulletin for Peer Review. EPA conducted several peer reviews in connection 

with data supporting the Tier 3 program, including new research on the effects of fuel

properties changes (including sulfur effects) on exhaust and evaporative emissions of 

Tier 2 vehicles. The refinery-by-refinery cost model was also peer reviewed. The peer 

review reports are located in the docket for today's action, as well as the agency's 

response to the peer review comments.

TABLE OF CONTENTS

I. EXECUTIVE SUMMARY AND PROGRAM OVERVIEW

A. Introduction

B. Overview of the Tier 3 Program

1. Major Public Comments and Key Changes from the Proposal

2. Key Components of the Tier 3 Program
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C. What Will the Impacts of the Standards Be?

II. WHY IS EPA TAKING THIS ACTION?

A. Basis for Action under the Clean Air Act

1. Clean Air Act Section 202

2. Clean Air Act Section 211

B. Overview of Public Health Impacts of Motor Vehicles and Fuels

1. Ozone

2. Particulate Matter

3. Oxides of Nitrogen and Sulfur

4. Carbon Monoxide

5. Mobile Source Air Toxics

6. Near-Roadway Pollution

7. Environmental Impacts of Motor Vehicles and Fuels

III. HOW WOULD THIS RULE REDUCE EMISSIONS AND AIR POLLUTION?

A. Effects of the Vehicle and Fuel Changes on Mobile Source Emissions

1. How Do Vehicles Produce the Emissions Addressed in this Action?

2. How Will the Changes to Gasoline Sulfur Content Affect Vehicle Emissions?

B. How Will Emissions Be Reduced?

1. NOX

2. VOC

3. CO

4. Direct PM2.5

5. Air Toxics

6. SO2

7. Greenhouse Gases

C. How Will Air Pollution Be Reduced?

1. Ozone

2. Particulate Matter

3. Nitrogen Dioxide

4. Air Toxics

5. Visibility
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6. Nitrogen and Sulfur Deposition

7. Environmental Justice

IV. VEHICLE EMISSIONS PROGRAM

A. Tier 3 Tailpipe Emission Standards for Light-Duty Vehicles, Light-Duty Trucks, 

and Medium-Duty Passenger Vehicles

1. How the Tier 3 Program is Harmonized with the California LEV III Program

2. Summary of the Tier 3 FTP and SFTP Tailpipe Standards

3. FTP Standards

4. SFTP Standards

5. Feasibility of the NMOG+NOX and PM Standards

6. Impact of Gasoline Sulfur Control on the Effectiveness of the Vehicle Emission 

Standards

7. Other Provisions

B. Tailpipe Emissions Standards for Heavy-Duty Vehicles

1. Overview and Scope of Vehicles Regulated

2. HDV Exhaust Emissions Standards

3. Supplemental FTP Standards for HDVs

4. HDV Emissions Averaging, Banking, and Trading

5. Feasibility of HDV Standards

6. Other HDV Provisions

C. Evaporative Emissions Standards

1. Tier 3 Evaporative Emission Standards

2. Program Structure and Implementation Flexibilities

3. Technological Feasibility

4. Heavy-Duty Gasoline Vehicle (HDGV) Requirements

5. Evaporative Emission Requirements for FFVs

6. Test Procedures and Certification Test Fuel

D. Improvements to In-Use Performance of Fuel Vapor Control Systems

1. Reasons for Adding a Leak Test Standard

2. Nature, Scope and Timing of Leak Standard

3. Leak Standard Test Procedure

4. Certification and Compliance
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a. In-Use Verification Program (IUVP) Requirements for the Leak Standard

E. Onboard Diagnostic System Requirements

1. Onboard Diagnostic (OBD) System Regulation Changes - Timing

2. Revisions to EPA OBD Regulatory Requirements

3. Provisions for Emergency Vehicles

4. Future Considerations

F. Emissions Test Fuel

1. Gasoline Emissions Test Fuel: Ethanol Content and Volatility

2. Other Gasoline Emissions Test Fuel Specifications

3. Flexible Fuel Vehicle Exhaust Emissions Test Fuel

4. Implementation Schedule

5. Implications of Emission Test Fuel Changes on CAFE Standards, GHG 

Standards, and Fuel Economy Labels

6. Consideration of Test Fuel for Nonroad Engines and Highway Motorcycles

7. CNG and LPG Emissions Test Fuel Specifications

G. Small Business Provisions

1. Lead Time and Relaxed Interim Standards

2. Assigned Deterioration Factors

3. Reduced Testing Burden and OBD Requirements

4. Hardship Relief

5. Eligibility for the Flexibilities

H. Compliance Provisions

1. Exhaust Emission Test Procedures

2. Reduced Test Burden

3. Miscellaneous Provisions

4. Manufacturer In-Use Verification Program (IUVP) Requirements

V. FUEL PROGRAM

A. Overview

1. Background

2. Summary of Final Tier 3 Fuel Program Standards

B. Annual Average Sulfur Standard
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C. Per-Gallon Sulfur Caps

1. Standards

2. Requirements for Gasoline Additives

D. Averaging, Banking, and Trading Program

1. How Will the ABT Program Assist with Compliance?

2. ABT Modeling

3. Eligibility

4. Credit Generation and Use

5. Credit Trading Provisions

6. ABT Provisions for Small Refiners and Small Volume Refineries

7. Deficit Carryforward

E. Additional Program Flexibilities

1. Regulatory Flexibility Provisions

2. Provisions for Refiners Facing Hardship Situations

F. Compliance Provisions

1. Registration, Reporting, and Recordkeeping Requirements

2. Sampling and Testing Requirements

3. Small Refiner Compliance

4. Small Volume Refinery Compliance

5. Attest Engagements, Violations, and Penalties

6. Special Fuel Provisions and Exemptions

G. Standards for Oxygenates (Including Denatured Fuel Ethanol) and Certified 

Ethanol Denaturants

H. Standards for Fuel Used in Flexible Fueled Vehicles

I. Sulfur Standards for Purity Butane and Purity Pentane Streams Blended into 

Gasoline

J. Standards for CNG and LPG

K. Refinery Air Permitting Interactions

1. Proposal

2. Updated Assessment of Tier 3 Refinery Changes and Permitting Implications

3. Comments and Responses

L. Refinery Feasibility
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1. Comments Received

2. Is it Feasible for Refiners to Comply with a 10 ppm Average Sulfur Standard?

3. Can Refiners Meet the January 1, 2017 Start Date?

M. Statutory Authority for Tier 3 Fuel Controls

1. Section 211(c)(1)(A)

2. Section 211(c)(1)(B)

3. Section 211(c)(2)(B)

4. Section 211(c)(2)(C)

VI. TECHNICAL AMENDMENTS AND REGULATORY STREAMLINING

A. Fuel Program Amendments

1. Fuels Program Regulatory Streamlining

2. Performance-Based Measurement Systems (PBMS)

3. Downstream Pentane Blending

4. Acceptance of Top Tier Deposit Control Test Data

5. Potential Broader Regulatory Streamlining Through Program Restructuring

B. Engine, Vehicle and Equipment Programs Amendments

1. Fuel Economy Labeling

2. Removing Obsolete Regulatory Text

3. Motorcycle Driving Schedules

4. Updating Reference Procedures

VII. WHAT ARE THE COST IMPACTS OF THE RULE?

A. Estimated Costs of the Vehicle Standards

1. What Changes Have Been Made to Vehicle Program Costs Since Proposal?

2. Summary of Vehicle Program Costs

B. Estimated Costs of the Fuel Program

1. Overview

2. Methodology

3. Fuel Program Costs

4. Other Cost Estimates

C. Summary of Program Costs

VIII. WHAT ARE THE ESTIMATED BENEFITS OF THE RULE?
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A. Overview

B. Quantified Human Health Impacts

C. Monetized Benefits

D. What are the Limitations of the Benefits Analysis?

E. Illustrative Analysis of Estimated Monetized Impacts Associated with the Rule in 

2018

IX. ALTERNATIVES ANALYSIS

A. Vehicle Emission Standards

1. Shorter NMOG+NOX Standard Phase-in

2. NMOG+NOX Standards Phase-in and Early Tier 3 Credits

3. NMOG+NOX Standards

4. PM Standards

5. Higher Ethanol Content of Emissions Test Fuel

B. Fuel Sulfur Standards

1. Annual Average Sulfur Standard

2. Refinery Gate Sulfur Cap

C. Program Start Date

X. ECONOMIC IMPACT ANALYSIS

A. Introduction

B. Vehicle Sales Impacts

C. Impacts on Petroleum Refinery Sector Production

D. Employment Impacts

1. Employment Impacts in the Auto Sector

2. Refinery Employment Impacts

XI. PUBLIC PARTICIPATION

XII. STATUTORY AND EXECUTIVE ORDER REVIEWS

A. Executive Order 12866: Regulatory Planning and Review and Executive Order 

13563: Improving Regulation and Regulatory Review

B. Paperwork Reduction Act

C. Regulatory Flexibility Act

1. Overview

2. Background
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3. Reason for Today’s Rule

4. Legal Basis for Agency Action

5. Summary of Potentially Affected Small Entities

6. Reporting, Recordkeeping, and Compliance

7. Related Federal Rules

8. Steps Taken to Minimize the Economic Impact on Small Entities

D. Unfunded Mandates Reform Act

E. Executive Order 13132: Federalism

F. Executive Order 13175: Consultation and Coordination with Indian Tribal 

Governments

G. Executive Order 13045: Protection of Children from Environmental Health Risks 

and Safety Risks

H. Executive Order 13211: Actions Concerning Regulations That Significantly Affect 

Energy Supply, Distribution, or Use

I. National Technology Transfer and Advancement Act

J. Executive Order 12898: Federal Actions to Address Environmental Justice in 

Minority Populations and Low-Income Populations

K. Congressional Review Act

XIII. STATUTORY PROVISIONS AND LEGAL AUTHORITY

I. Executive Summary and Program Overview 

A. Introduction

In this action, EPA is finalizing a major program designed to reduce air pollution 

from passenger cars and trucks. This program includes new standards for both vehicle 

emissions and the sulfur content of gasoline, considering the vehicle and its fuel as an 

integrated system. We refer to this program as the “Tier 3” vehicle and fuel standards. 

This rule is part of a comprehensive approach to address the impacts of motor 

vehicles on air quality and public health. Over 149 million Americans are currently 

experiencing unhealthy levels of air pollution, which are linked with respiratory and 

cardiovascular problems and other adverse health impacts that lead to increased 

medication use, hospital admissions, emergency department visits, and premature 
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mortality.

1

 Motor vehicles are a particularly important source of exposure to air 

pollution, especially in urban areas. By 2018, we project that in many areas that are not 

attaining health-based ambient air quality standards (i.e., “nonattainment areas”), 

passenger cars and light trucks will contribute 10-25 percent of total nitrogen oxides 

(NOX) emissions, 15-30 percent of total volatile organic compound (VOC) emissions, 

and 5-10 percent of total direct particulate matter (PM2.5) emissions.2 These compounds 

form ozone, PM, and other air pollutants, whose health and environmental effects are 

described in more detail in Section II. Cars and light trucks also continue to be a 

significant contributor to air pollution directly near roads, with gasoline vehicles 

accounting for more than 50 percent of near-road concentrations of some criteria and 

toxic pollutants.3 More than 50 million people live, work, or go to school in close 

proximity to high-traffic roadways, and the average American spends more than one hour 

traveling along roads each day.

4,5 Over 80 percent of daily trips use personal vehicles.6

The standards set forth in this rule will significantly reduce levels of multiple air 

pollutants (such as ambient levels of ozone, PM, nitrogen dioxide (NO2), and mobile 

source air toxics (MSATs)) across the country, with immediate benefits from the gasoline 

sulfur control standards starting in 2017. These reductions will help state and local 

agencies in their effort to attain and maintain health-based National Ambient Air Quality

Standards (NAAQS). Few other national strategies exist that will deliver the same 

magnitude of multi-pollutant reductions and associated public health protection that is 

projected to result from the Tier 3 standards. Without this action to reduce nationwide 

motor vehicle emissions, areas would have to adopt other, less cost-effective measures to 

reduce emissions from other sources under their state or local authority. In the absence of 

additional controls, certain areas would continue to have ambient ozone concentrations 

exceeding the NAAQS in the future. See Section III.C for more details.

 

1 The 149 million represents people living in O3, PM2.5, PM10, and SO2 nonattainment areas. Data come 

from Summary Nonattainment Area Population Exposure Report, current as of December 5, 2013 at: 

http://www.epa.gov/oar/oaqps/greenbk/popexp.html and contained in Docket EPA-HQ-OAR-2011-0135.

2 Mobile source contributions derived from inventories developed for this rule. For more information on 

these inventories see the Emissions Inventory Technical Support Document (TSD) for the final Tier 3 Rule, 

Docket ID No. EPA-HQ-OAR-2011-0135.

3

For example, see Fujita, E.M; Campbell, D.E.; Zielinska, B.; Arnott, W.P.; Chow, J.C. (2011) 

Concentrations of Air Toxics in Motor Vehicle-Dominated Environments. Health Effects Institute 

Research Report 156. Available at http://www.healtheffects.org

4 U.S. Census Bureau (2011). Current Housing Reports, Series H150/09, American Housing Survey for the 

United States: 2009. U.S. Government Printing Office, Washington, DC. Available at 

http://www.census.gov/hhes/www/housing/ahs/ahs09/ahs09.html. (Note that this survey includes estimates 

of homes within 300 feet of highways with four or more lanes, railroads, and airports.)

5 Drago, R. (2011). Secondary activities in the 2006 American Time Use Survey. U.S. Bureau of Labor 

Statistics Working Paper 446. Available at http://www.bls.gov

6

 Santos, A.; McGuckin, N, Yukiko Nakamoto, H.; Gray, D.; Liss, S. (2011) Summary of Travel Trends: 

2009 National Household Travel Survey. Federal Highway Administration report no FHWA-PL-11-022. 

Available at http://nhts.ornl.gov/publications.shtml.
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The Clean Air Act authorizes EPA to establish emissions standards for motor 

vehicles to address air pollution that may reasonably be anticipated to endanger public 

health or welfare (section 202). EPA also has authority to establish fuel controls to 

address such air pollution (section 211). These statutory authorities are described in 

Section II.A. 

The vehicle and gasoline sulfur standards we are finalizing represent a “systems 

approach” to reducing vehicle exhaust and evaporative emissions by addressing the 

vehicle and fuel as a system. The systems approach enables emission reductions that are 

both technologically feasible and cost-effective beyond what would be possible looking 

at vehicle and fuel standards in isolation. We first applied such an approach with our 

Tier 2 vehicle/gasoline sulfur standards (finalized in 2000).7 We believe that a similar 

approach for the Tier 3 standards is a cost-effective way to achieve substantial additional 

emissions reductions. 

The Tier 3 standards include new light- and heavy-duty vehicle emission 

standards for exhaust emissions of VOC (specifically, non-methane organic gases, or 

NMOG), NOX, and PM, as well as new evaporative emissions standards. The fully

phased-in standards for light-duty vehicle, light-duty truck, and medium-duty passenger 

vehicle tailpipe emissions are an 80 percent reduction in fleet average NMOG+NOX

compared to current standards, and a 70 percent reduction in per-vehicle PM standards. 

The fully phased-in Tier 3 heavy-duty vehicle tailpipe emissions standards for 

NMOG+NOX and PM are on the order of 60 percent lower than current standards. 

Finally, the fully phased-in evaporative emissions standards represent a 50 percent 

reduction from current standards.

The vehicle emission standards, combined with the reduction of gasoline sulfur 

content from the current 30 parts per million (ppm) average down to a 10 ppm average, 

will result in dramatic emissions reductions for NOX, VOC, direct PM2.5, carbon 

monoxide (CO) and air toxics. For example, in 2030, when Tier 3 vehicles will make up 

the majority of the fleet as well as vehicle miles traveled, NOX and VOC emissions from 

on-highway vehicles will be reduced by about 21 percent, and CO emissions will be 

reduced by about 24 percent. National emissions of many air toxics from on-highway

vehicles will also be reduced by 10 to nearly 30 percent. Reductions will continue 

beyond 2030 as more of the fleet is composed of vehicles meeting the fully phased-in 

Tier 3 standards. For example, the Tier 3 program will reduce on-highway emissions of 

NOX and VOC nearly 31 percent by 2050, when vehicles meeting the fully phased-in Tier 

3 standards will comprise almost the entire fleet.

Gasoline vehicles depend to a great degree on catalytic converters to reduce levels 

of pollutants in their exhaust, including NMOG and NOX, as well as PM (specifically, the 

 

7

65 FR 6698 (February 10, 2000)
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volatile hydrocarbon fraction), CO, and most air toxics. The catalytic converters become 

significantly less efficient when exposed to sulfur. The Tier 2 rulemaking required 

refiners to take steps to reduce sulfur levels in gasoline by approximately 90 percent, to 

an average of 30 ppm. As discussed in Section IV.A.6, subsequent research provides a 

compelling case that even this level of sulfur not only degrades the emission performance 

of vehicles on the road today, but also inhibits necessary further reductions in vehicle 

emissions performance to reach the Tier 3 standards. Thus, the 10 ppm average sulfur 

standard for Tier 3 is significant in two ways: it enables vehicles designed to the Tier 3 

tailpipe exhaust standards to meet these standards in-use for the duration of their useful 

life, and it facilitates immediate emission reductions from all the vehicles on the road at 

the time the fuel sulfur controls are implemented. EPA is not the first regulatory agency

to recognize the need for lower-sulfur gasoline. Agencies in Europe and Japan have 

already imposed gasoline sulfur caps of 10 ppm, and the State of California is already 

averaging 10 ppm sulfur with a per gallon cap of 20 ppm. Other states are preempted by 

the Clean Air Act from adopting new fuel programs to meet air quality objectives. 

Consequently, they could not receive the air quality benefits of lower sulfur gasoline 

without federal action. 

This action is one aspect of a comprehensive national program regulating 

emissions from motor vehicles. EPA’s final rule for reducing greenhouse gas (GHG) 

emissions from light-duty (LD) vehicles starting with model year (MY) 2017 (referred to 

here as the “2017 LD GHG” standards) is another aspect of this comprehensive program.8 

The Tier 3 program addresses interactions with the 2017 LD GHG rule in a manner that 

aligns implementation of the two actions, to achieve significant criteria pollutant and 

GHG emissions reductions while providing regulatory certainty and compliance 

efficiency. As vehicle manufacturers introduce new vehicle platforms for compliance 

with the GHG standards, they will be able to design them for compliance with the Tier 3 

standards at the same time. The Tier 3 standards are also closely coordinated with 

California’s Low Emission Vehicle (LEV) III program to create a vehicle emissions 

program that will allow automakers to sell the same vehicles in all 50 states. (In 

December 2012 EPA approved a waiver of Clean Air Act preemption for the California 

Air Resources Board’s (CARB’s) LEV III program with compliance beginning in 2015. 

Twelve states adopted the LEV III program under Section 177 of the Clean Air Act.9) 

We have worked closely with individual vehicle manufacturers and their trade 

associations, who have emphasized the importance of a harmonized national program. 

Together, the Tier 3, 2017 LD GHG, and LEV III standards will provide significant 

reductions in GHGs, criteria pollutants and air toxics from motor vehicles while 

streamlining programs and enabling manufacturers to design a single vehicle for 

 

8 EPA’s GHG standards are part of a joint National Program with the National Highway Traffic Safety 

Administration, which also set coordinated standards for Corporate Average Fuel Economy (CAFE). 77

FR 62623 (October 15, 2012).

9 These states include Connecticut, Delaware, Maryland, Maine, Massachusetts, New Jersey, New York, 

Oregon, Pennsylvania, Rhode Island, Washington, and Vermont.
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nationwide sales, thus reducing their costs of compliance. In this way, the Tier 3 

program responds to the May 21, 2010 Presidential Memorandum that requested that 

EPA develop a comprehensive approach toward regulating motor vehicles, including 

consideration of non-GHG emissions standards.10

As part of the systems approach to this program, we have considered the types of 

fuels on which vehicles will be operating in the future. In particular, the renewable fuels 

mandate that was revised by the Energy Independence and Security Act (EISA) and is 

being implemented through the Renewable Fuel Standards program (RFS2)11 is resulting 

in the use of significant amounts of ethanol-blended gasoline. We are updating the 

specifications of the emissions test fuel with which vehicles demonstrate compliance with 

emissions standards, in order to better reflect the ethanol content and other properties of 

gasoline that is in use today and is expected in future years.

Section I provides an overview of the vehicle and fuel standards we are finalizing 

as well as the impacts of the standards. The public health issues and statutory

requirements that have prompted this action are described in Section II, and our 

discussion of how the Tier 3 standards will reduce emissions and air pollution is 

presented in Section III. Details of the standards and how they will be implemented can 

be found in Sections IV through VI. Sections VII through X contain our discussion of 

the standards’ technological feasibility and costs, benefits, and economic impacts. 

Sections XI through XIII address public participation, statutory and executive orders, and 

statutory provisions and legal authority under the Clean Air Act covered in this 

rulemaking. 

This final rule is based on extensive public input received in response to EPA’s 

Tier 3 proposal. The proposal was signed and posted on the EPA website on March 29, 

2013, and published in the Federal Register on May 21, 2013. EPA held two public 

hearings in Philadelphia and Chicago in April 2013. In response to stakeholder requests, 

EPA extended the public comment period to July 1, 2013. We received more than 

200,000 public comments. A broad range of stakeholders provided comments, including 

state and local governments, auto manufacturers, emissions control suppliers, refiners, 

fuel distributors and others in the petroleum industry, renewable fuels providers, 

environmental organizations, consumer groups, labor groups, private citizens, and others. 

Some of the issues raised in comments included lead time and the program’s start date, 

the vehicle manufacturers’ support for a 50-state program harmonized with California, 

the need for and degree of gasoline sulfur control (including the level of the sulfur cap), 

the ethanol content of vehicle certification test fuel, and various details on the flexibilities 

and other program design features of both the vehicle and fuels standards.

 

10 The Presidential Memorandum is found at: http://www.whitehouse.gov/the-press-office/presidentialmemorandum-regarding-fuel-efficiency-standards.

11 75 FR 14670 (March 26, 2010).
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B. Overview of the Tier 3 Program

In the 14 years since EPA established the Tier 2 Vehicle Program, manufacturers 

of light-duty vehicles and automotive technology suppliers have continued to develop a 

wide range of improved technologies capable of reducing vehicle emissions. The 

California LEV II program has been instrumental in the continuous technology

improvements by requiring year after year reductions in fleet average hydrocarbon levels, 

in addition to requiring the introduction of advanced exhaust and evaporative emission 

controls in partial zero emission vehicles (PZEVs). This technological progress has made 

it possible for manufacturers to achieve emission reductions well beyond the 

requirements of the Tier 2 program if gasoline sulfur levels are lowered further. 

As a result, in conjunction with lower gasoline sulfur standards, we are 

establishing new Tier 3 standards for exhaust emissions of NMOG, NOX, and PM, as 

well as for evaporative hydrocarbon emissions. These vehicle emissions standards will 

phase in beginning with MY 2017. The structure of the Tier 3 standards is very similar to 

that of the existing Tier 2 program. As with the Tier 2 program, the standards will apply

to all light-duty vehicles (LDVs, or passenger cars), light-duty trucks (LDT1s, LDT2s, 

LDT3s, and LDT4s) and Medium-Duty Passenger Vehicles (MDPVs). We also are 

establishing separate but closely related standards for heavy-duty vehicles up to 14,000 

lbs Gross Vehicle Weight Rating (GVWR).12 We have concluded that the vehicle 

emissions standards, in conjunction with the reductions in fuel sulfur also required by this 

action, are feasible across the fleet in the timeframe provided. 

Auto manufacturers have stressed the importance of being able to design, 

produce, and sell a single fleet of vehicles in all 50 states that complies with both the Tier 

3 and California LEV III programs, as well as the greenhouse gas (GHG)/Corporate 

Average Fuel Economy (CAFE) programs in the same timeframe. To that end, we 

worked closely with the California Air Resources Board and vehicle manufacturers to 

align the two programs as closely as possible. This consistency among the federal and 

California programs means that manufacturers do not need to design unique versions of 

vehicles with different emission control hardware and calibrations for different 

geographic areas. This allows manufacturers to avoid the additional costs of parallel 

design, development, calibration, and manufacturing. We also have designed the Tier 3 

program to be implemented in the same timeframe as the GHG emissions and fuel 

economy standards for model years 2017-2025. We expect that in response to these 

programs, manufacturers will be developing entirely new powertrains for most of their 

vehicles. Because the Tier 3 standards will phase in over the same timeframe, 

manufacturers are in a better position to simultaneously respond to all of these 

requirements.

 

12 These heavy-duty vehicles were not included in the Tier 2 program but were subject to standards in a 

subsequent rule covering the heavy-duty sector (66 FR 5002, January 18, 2001). 
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Overall, the final Tier 3 program is very similar to the program we proposed. As 

discussed below and throughout this preamble, the program phases in over several years 

– with the primary vehicle emission standards starting in Model Year (MY) 2017 (2018 

for heavier vehicles) and the gasoline sulfur control provisions beginning in 2017. 

As discussed above, we received a large number and wide range of comments on 

the proposed rule. Several comments raise particularly significant issues concerning 

some fundamental components of the Tier 3 program, including when the vehicle-related 

and fuel-related requirements begin. We briefly discuss these key issues in this section, 

and in more detail later in this preamble. The Summary and Analysis of Comments 

document provides our responses to the comments we received; it is located in the docket 

for this rulemaking and also on EPA’s website at www.epa.gov/otaq/tier3.htm.

1. Major Public Comments and Key Changes from the Proposal

a. Start Date and Lead Time Issues

(1) Gasoline Sulfur Control Program

Many stakeholders commented on the proposed 2017 start date of the Tier 3 

program, with state and NGO organizations supporting finalizing the standards as 

proposed. Conversely, refiners, importers, and others in the fuel industry commented that 

they believed the proposed start date would not provide a sufficient amount of lead time 

to meet the requirements of the Tier 3 program, and that EPA has historically provided at 

least four years of lead time in previous fuels rulemakings. These commenters noted that 

five years of lead time is needed to allow for necessary refinery changes to be made 

during a refinery’s normal turnaround/shutdown schedule (these occur every four years, 

on average) and to allow adequate time for the permitting process. These commenters 

also stated that, given the proposed flexibility provisions for vehicles, that a 2017 fuel 

program start date was not truly needed to enable the vehicle technology. Further, these 

commenters stated that they believed insufficient lead time would drive up the costs for 

regulated entities as they would need to do unscheduled shutdowns to install and/or 

revamp equipment to meet the proposed standards. Lastly, they stated that the 

uncertainty regarding the potential availability of credits would make meeting a 2017 

start date more challenging.

As discussed in greater detail in Section V below, we are finalizing the proposed 

start date of January 1, 2017. We understand refiners’ concerns, including their concerns 

over the necessary capital investments and potential off-cycle turnarounds/shutdowns to 

make refinery modifications for Tier 3. In light of these concerns, we are finalizing

additional flexibilities beyond those already in the proposal and we are confident that the 

program being finalized today addresses these concerns. Considering all the flexibilities 

offered to regulated parties, there is, in effect, nearly 6 years of time to comply provided 

for those refineries that may need it. As discussed in Section V.D, we are finalizing a 

credit averaging, banking, and trading (ABT) program that will allow for a smooth 
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transition from the Tier 2 to Tier 3 ABT programs (including provisions for early credit 

generation beginning in 2014). These early credit provisions, coupled with the ability to 

carry over credits from Tier 2 into Tier 3 (an additional flexibility being finalized today

that was not part of the proposal), will allow for early actions to reduce sulfur levels by 

some refineries to be used to delay the need for actions at other refineries until 2020. 

This structure of the ABT program allows refiners and importers the flexibility to choose 

the most economical compliance strategy – investment in technology, use of credits, or 

both – for meeting the Tier 3 average gasoline sulfur standard. In addition, approved 

small refiners and small volume refineries are given an additional three years from the 

January 1, 2017, Tier 3 program start date to comply (January 1, 2020).

We proposed that the Tier 2 ABT program would not only be separate from the 

Tier 3 ABT program, but that it would also end at the start of the Tier 3 program in 2017. 

The implications of this meant that any Tier 2 credits generated after 2012 would run the 

risk of expiring before the end of their full five-year life if they were not used before 

January 1, 2017. Commenters requested that EPA consider allowing such Tier 2 

“banked” credits to receive their full five-year life. This would eliminate any incentive 

refiners may have to use these credits prior to the end of the Tier 2 program to raise their 

in-use sulfur levels. The ABT program that we are finalizing today enables a seamless 

transition from Tier 2 to Tier 3, including an allowance for Tier 2 banked credits to be 

used for their full five-year life or through December 31, 2019, whichever is earlier. Not 

only does this provision effectively provide more lead time and flexibility for refiners and 

importers, but we believe these banked credits will help to provide certainty of the 

availability of credits for refiners and importers who may want to rely on them for 

compliance.

Finally, as discussed in Section V.E.2, we are also finalizing hardship provisions 

that allow refiners to petition for delayed compliance, on a case-by-case basis, for 

situations of extreme hardship or extreme unforeseen circumstances. These provisions, 

similar to those implemented in past fuel rulemakings, provide a safety valve should all 

the other flexibilities provided prove insufficient. As part of these hardship provisions, 

we are finalizing the ability for refiners to carry a deficit for up to 3 years, providing them 

with yet additional flexibility during the transition to Tier 3 should it prove necessary.

(2) Vehicle Emission Control Program

There were no major concerns raised for the proposed MY 2017 start date for 

lighter light-duty vehicles, although commenters from the auto manufacturing industry

raised concerns about the lead time we proposed for heavier light-duty vehicles. 

Specifically, commenters pointed to Clean Air Act section 202(a)(3)(C) that, for vehicles 

over 6,000 lbs GVWR, requires that EPA emission standards provide at least four years 

of lead time and three years of regulatory stability. 

In light of this statutory requirement, in addition to the primary declining fleet 

average standards starting in MY 2018 for heavier vehicles, EPA proposed an alternative 
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phase-in schedule for any manufacturer that prefers a longer lead time and annual 

stability for these vehicles in lieu of the declining fleet average standards option. The 

commenters stated that the proposed alternative pathway would be too difficult to take 

advantage of in comparison to the primary program and thereby failed to comply with the 

Clean Air Act. 

In considering these comments, EPA also considered that during the development 

of the Tier 3 program and in their comments, the same auto industry commenters 

consistently urged EPA to design the Tier 3 program to harmonize with the California 

LEV III standards as closely and as early as possible. As discussed in detail below in 

Section IV.A, extensive data that EPA has generated or received continue to support the 

conclusion that the primary fleet-average standards provide a compliance path that is 

feasible across the industry and that closely harmonizes with LEV III. EPA believes that 

we have reasonably resolved these somewhat competing concerns -- early harmonization 

vs. additional lead time -- by finalizing the primary declining fleet average standards as 

proposed while also finalizing revised alternative phase-in compliance schedules (see 

Section IV.A.2.c). In response to the comments on this topic, we have revised the 

alternative phase-in schedules to reduce their associated burden for manufacturers, while 

still maintaining environmental benefits that are equivalent to the primary program. We 

also include provisions in the percent-of-sales phase-in alternatives that allow 

manufacturers to exclude vehicle models that begin their 2019 model year production 

early in 2018, in order to provide four years of lead time. 

b. Emissions Test Fuel

In-use gasoline has changed considerably since EPA last revised specifications for 

the test gasoline used in emissions testing of light- and heavy-duty vehicles. Perhaps 

most importantly, gasoline containing 10 percent ethanol by volume (E10) has replaced 

non-oxygenated gasoline (E0) across the country. As a result, we are updating federal 

emissions test fuel specifications to better match in-use fuel. 

In the NPRM, EPA proposed that the specified gasoline for emissions testing be 

changed from E0 to E15 as a forward-looking approach. Since then, several factors have 

led EPA to reconsider that approach, including minimal proliferation on a national scale 

of stations offering E15 and the complexities that E15 would introduce for long-term 

harmonization with California’s use of E10 in their LEVIII program. We received 

comments from a broad set of stakeholders including the auto and oil industries, states, 

and NGOs with a general consensus that E15 would not be appropriate as the official test 

fuel at this time. Ethanol industry commenters supported E15 certification fuel, but 

provided no timeline by which this blend level would be representative of in-use fuel. In 

light of the comments received and EPA’s assessment of the current and projected levels 

of ethanol in gasoline in use, we are finalizing E10 as the new emissions test fuel.

In deciding to finalize E10 test fuel, EPA considered whether to change the 

volatility of the test fuel, typically expressed as pounds per square inch (psi) Reid Vapor 
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Pressure (RVP). As discussed in detail in Section IV.F, after considering technical and 

policy implications as well as stakeholder comments, we have concluded that the most 

appropriate approach is to maintain an RVP of 9 psi for the E10 emissions test fuel at this 

time. EPA considered raising test fuel RVP to 10 psi, but decided to leave it unchanged 

at 9 psi based on what would have been the associated increase in stringency of the Tier 3 

evaporative standard with 10 psi and the loss of regulatory harmony on evaporative 

emissions with California’s LEV III program. 

As a result, after reassessing market trends and considering comments, EPA 

concludes that the most appropriate approach is to finalize an ethanol content of 10 

percent and an RVP of 9 psi for emissions test gasoline. We will continue to monitor 

ethanol trends in the gasoline market, as discussed later in this preamble. 

c. Gasoline Sulfur Caps

As described in more detail in Section V.C. we proposed two options for the Tier 

3 per-gallon sulfur caps—maintaining the Tier 2 refinery gate sulfur cap of 80 ppm (with 

a 95 ppm downstream sulfur cap), and lowering to a 50 ppm refinery gate sulfur cap 

beginning January 1, 2020 (with a 65 ppm downstream cap). We received comments 

supporting lower per-gallon caps which noted potential environmental benefits, greater 

certainty that vehicles would see lower and more uniform gasoline sulfur levels, and the 

ability to enable new vehicle technologies requiring very low sulfur levels. Conversely, 

comments received in support of maintaining the Tier 2 per-gallon caps cited concerns on 

cost, flexibility for turnarounds/unplanned shutdowns (due to refinery fires, natural 

disasters, etc.), and gasoline supply and/or price impacts.

Analysis performed since the time of the proposal found that a lower refinery gate 

cap would likely result in higher costs to the fuels industry and a decreased ability to 

handle off-spec product (potentially impacting gasoline supply and pricing), without any

significant increase in the nationwide emissions reductions provided by the Tier 3 

program. Thus, in today’s action we are retaining the Tier 2 per-gallon sulfur caps. The 

80 ppm refinery gate cap will provide refiners needed flexibility in allowing for 

naturally-occurring fuel batch variability, as well as more certainty that they will be able 

to continue producing and distributing gasoline during turnarounds/upsets to avoid a total 

shutdown. It will also provide more certainty for transmix processors, additive 

manufacturers, and other downstream parties in producing gasoline.

However, we do understand commenters’ concerns that retaining the Tier 2 sulfur 

caps might create regional differences in the benefits of the Tier 3 program. Therefore 

we will continue to monitor in-use sulfur levels and their impact on vehicle emissions to 

ascertain whether a future reduction in the per-gallon cap may be necessary.
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d. Effect of Gasoline Sulfur on Tier 3 Vehicle Emissions

The need for and level of gasoline sulfur control was a key issue raised in public 

comments. The petroleum industry raised concerns that there was insufficient basis for 

the proposed 10 ppm average sulfur level, while auto manufacturers and emissions 

control equipment manufacturers stressed that the feasibility of the Tier 3 vehicle 

standards was dependent on near-zero gasoline sulfur levels. This issue is discussed in 

detail below in Section IV.A.6. In sum, EPA believes that the range of studies conducted 

by EPA and others in recent years, along with the comments submitted by the auto 

industry and emissions control manufacturers during the comment period and more 

recently, strongly reinforce our conclusion that the impact of gasoline sulfur poisoning on 

exhaust catalyst performance is significant. 

Sulfur is a well-known catalyst poison. The nature of sulfur’s interactions with 

active catalytic materials is complex and varies with catalyst composition, exhaust gas 

composition, and exhaust temperature. Thus, even if a manufacturer were able to certify 

a new vehicle to the new stringent standards, the manufacturer’s ability to maintain the 

emission performance of that vehicle in-use is greatly jeopardized if the vehicle is being 

operated on gasoline sulfur levels greater than 10 ppm. In fact, due to the variation in 

actual vehicle operation, any amount of gasoline sulfur will deteriorate catalyst 

efficiency. Vehicle manufacturers and suppliers, both individually and through their 

trade associations, stressed the need for gasoline sulfur to be reduced to near zero levels 

in order for them to meet the proposed standards. However, we believe that a 10 ppm 

average sulfur level is sufficiently low to enable compliance with the Tier 3 vehicle 

standards, and as described below and in Section V, reducing sulfur levels further would 

cause sulfur control costs to quickly escalate. 

Taken together, this information provides a compelling argument that the 

fleetwide Tier 3 vehicle standards are achievable only with a reduction of gasoline sulfur 

content from the current 30 ppm average down to a 10 ppm average. 

e. SFTP (US06) PM Standard for Light-Duty Vehicles

The final Tier 3 vehicle standards are largely unchanged from their proposed 

levels. One change from the proposal is the PM emissions standards as measured on the 

US06 test cycle. The US06 cycle is part of the composite Supplemental Federal Test 

Procedure (SFTP) and simulates aggressive driving. The US06 PM standards are part of 

the suite of Tier 3 tailpipe standards that limit emissions under a wide range of common 

vehicle driving conditions. Newer emissions test data presented in the NPRM, as well as 

more recent additional test data submitted in public comments, show that a numerically 

lower US06 PM standard is feasible and appropriately reflects the actual emissions 

performance achieved by many vehicles in the fleet today while preventing increased 

emissions in the future. 
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Taken together, the test results clearly show that most current light-duty vehicles 

– regardless of engine technology, emission control strategy, or vehicle size – are 

performing at much lower US06 emission levels than previously documented. Based on 

these newer data, we believe that it is appropriate to finalize a numerically lower US06 

PM emission standard for LDVs, LDTs, and MDPVs, and to set a single standard for 

both lighter and heavier vehicles in this vehicle segment. In general, the final US06 PM 

standard for these vehicles begins to phase in at a level of 10 mg/mi in MYs 2017 and 

2018, stepping down to a level of 6 mg/mi in MY2019. See Section IV.A.4.b for 

additional discussion of the US06 standards and how they will phase in. 

2. Key Components of the Tier 3 Program

a. Tailpipe Standards for Light-Duty Vehicle, Light-Duty Truck, and MediumDuty Passenger Vehicle Tailpipe Emissions

We are establishing a comprehensive program that includes new fleet-average 

standards for the sum of NMOG and NOX tailpipe emissions (presented as NMOG+NOX) 

as well as new per-vehicle standards for PM.13 These standards, when applied in 

conjunction with reduced gasoline sulfur content, will result in very significant 

improvements in vehicle emissions from the levels of the Tier 2 program. For these 

pollutants, the standards are measured on test procedures that represent a range of vehicle 

operation, including the Federal Test Procedure (or FTP, simulating typical driving) and 

the Supplemental Federal Test Procedure (or SFTP, a composite test simulating higher 

ambient temperatures, higher vehicle speeds, and quicker accelerations). In addition to 

the standards, we are extending the regulatory useful life period during which the 

standards apply (see Section IV.A.7.b below) and making test fuel more representative of 

expected real-world fuel (see Section I.B.2.e below). The final standards are in most 

cases identical to those of California’s LEVIII program, which provides the 50-state 

harmonization strongly supported by the auto industry. 

As proposed, the new Tier 3 FTP and SFTP NMOG+NOX standards are fleetaverage standards, meaning that a manufacturer calculates the average emissions of the 

vehicles it sells in each model year and compares that average to the applicable standard 

for that model year. The manufacturer certifies each of its vehicles to a per-vehicle “bin” 

standard (see Section IV.A.2) and sales-weights these values to calculate its fleet-average 

NMOG+NOX emissions for each model year. Table I-1 summarizes the fleet average 

standards for NMOG+NOX evaluated over the FTP. The standards for light-duty

vehicles begin in MY 2017 at a level representing a 46 percent reduction from the Tier 2 

requirements. For the light-duty fleet over 6000 lbs GVWR, and MDPVs, the standards 

apply beginning in MY 2018. As shown, these fleet-average standards decline during the 

first several years of the program, becoming increasingly stringent until ultimately

 

13A discussion of the reasons for combining NMOG and NOX for this purpose is in Section IV.A.3.a below.
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reaching an 81 percent reduction when the transition is complete. The FTP NMOG+NOX

program includes two separate sets of declining fleet-average standards, with LDVs and 

small light trucks in one grouping and heavier light trucks and MDPVs in a second 

grouping, that converge at 30 milligrams per mile (mg/mi) in MY 2025 and later. As 

mentioned above, we are also providing alternative percent phase-in schedules for this 

and the other light-duty standards. 

Table I-1 Tier 3 LDV, LDT, and MDPV Fleet Average FTP NMOG+NOX

Standards (mg/mi) 

Model Year

2017a2018 2019 2020 2021 2022 2023 2024 2025 

and later

LDV/LDT1b86 79 72 65 58 51 44 37 30

LDT2,3,4 and 

MDPV

101 92 83 74 65 56 47 38 30

a For LDV and LDTs above 6000 lbs GVWR and MDPVs, the fleet average standards apply beginning in 

MY 2018.

b These standards apply for a 150,000 mile useful life. Manufacturers can choose to certify some or all of 

their LDVs and LDT1s to a useful life of 120,000 miles. If a vehicle model is certified to the shorter useful 

life, a proportionally lower numerical fleet-average standard applies, calculated by multiplying the 

respective 150,000 mile standard by 0.85 and rounding to the nearest mg. See Section IV.A.7.c. 

Similarly, as proposed, the NMOG+NOX standards measured over the SFTP are 

fleet-average standards, declining from MY 2017 until MY 2025, as shown in Table I-2. 

In this case, the same standards apply to both lighter and heavier vehicles in the lightduty fleet. In MY 2025, the SFTP NMOG+NOX standard reaches its final fleet average 

level of 50 mg/mi.

Table I-2 Tier 3 LDV, LDT, and MDPV Fleet Average SFTP NMOG+NOX

Standards (mg/mi)

Model Year

2017a2018 2019 2020 2021 2022 2023 2024 2025 

and later

NMOG + NOX 103 97 90 83 77 70 63 57 50

a For LDVs and LDTs above 6000 lbs GVWR and MDPVs, the fleet average standards apply beginning in 

MY 2018. 

As proposed, manufacturers can also earn credits if their fleet average 

NMOG+NOX performance is better than the applicable standard in any model year. 

Credits that have been previously banked or obtained from other manufacturers can be 

used, or credits can be traded to other manufacturers. Manufacturers would also be 
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allowed to carry forward deficits in their credit balance. (See Sections IV.A.7.a and 

IV.A.7.m).

We are also establishing PM standards as part of the Tier 3 program, for both the 

FTP and US06 cycles (as described above, US06 is a component of the SFTP test). 

Research has demonstrated that the level of PM from gasoline light-duty vehicles is more 

significant than previously thought.14 Although many vehicles today are performing at or 

near the levels of the new standards, the data indicate that improvements, especially in 

high-load fuel control and in the durability of engine components, are possible. 

Under typical driving, as simulated by the FTP, the PM emissions of most 

current-technology gasoline vehicles are fairly low at certification and in use, well below 

the Tier 2 PM standards. At the same time we see considerable variation in PM 

emissions among vehicles of various makes, models, and designs. As a result, as 

proposed, we are setting the new FTP PM standard at a level that will ensure that all new 

vehicles perform at the level already being achieved by well-designed Tier 2 vehicles. 

The PM standards apply to each vehicle separately (i.e., not as a fleet average). Also, in 

contrast to the declining NMOG+NOX standards, the PM standard on the FTP for 

certification testing is 3 mg/mi for all vehicles and for all model years. As for the 

NMOG+NOX standards, for vehicles over 6000 lbs GVWR, the FTP PM standard applies 

beginning in MY 2018. Manufacturers can phase in their vehicle models as a percent of 

U.S. sales through MY 2022. Most vehicles are already performing at this stringent PM 

level, and the primary intent of the standard is to bring all light-duty vehicles to the 

typical level of PM performance being demonstrated by many of today’s vehicles. 

As proposed, the Tier 3 program also includes a temporary in-use FTP PM 

standard of 6 mg/mi for the testing of in-use vehicles that applies during the percent 

phase-in period only. This in-use standard will address the in-use variability and 

durability uncertainties that accompany the introduction of new technologies. Table I-3

presents the FTP certification and in-use PM standards and the phase-in percentages. 

Table I-3 Phase-In for Tier 3 FTP PM Standards 

2017a2018 2019 2020 2021 2022 and 

later

Phase-In

(percent of U.S. sales)

20b20 40 70 100 100

Certification 

Standard (mg/mi)

3 3 3 3 3 3

 

14 Nam, E.; Fulper, C.; Warila, J.; Somers, J.; Michaels, H.; Baldauf, R.; Rykowski, R.; and Scarbro, C. 

(2008). Analysis of Particulate Matter Emissions from Light-Duty Gasoline Vehicles in Kansas City, 

EPA420-R-08-010. Assessment and Standards Division Office of Transportation and Air Quality U.S. 

Environmental Protection Agency Ann Arbor, MI, April 2008.
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In-Use Standard 

(mg/mi)

6 6 6 6 6 3

a

For LDVs and LDTs above 6000 lbs GVWR and MDPVs, the FTP PM standards apply beginning in MY 

2018.

b Manufacturers comply in MY 2017 with 20 percent of their LDV and LDT fleet under 6,000 lbs GVWR, or 

alternatively with 10 percent of their total LDV, LDT, and MDPV fleet. 

Finally, as discussed in Section I.B.1.e above, the Tier 3 program includes PM 

standards evaluated over the US06 driving cycle (the US06 is one part of the SFTP 

procedure) of 10 mg/mi through MY 2018 and of 6 mg/mi for 2019 and later model 

years, for light-duty vehicles. As in the case of the FTP PM standards, the intent of the 

US06 PM standard is to bring the emission performance of all vehicles to that already 

being demonstrated by many vehicles in the current light-duty fleet. 

b. Heavy-Duty Vehicle Tailpipe Emissions Standards

As discussed in detail in Section IV.B, we are setting Tier 3 exhaust emissions 

standards for complete heavy-duty vehicles (HDVs) between 8,501 and 14,000 lbs 

GVWR. Vehicles in this GVWR range are often referred to as Class 2b (8,501-10,000 

lbs) and Class 3 (10,001-14,000 lbs) vehicles, and are typically heavy-duty pickup trucks 

and work or shuttle vans. Most are built by companies with even larger light-duty truck 

markets, and as such they frequently share major design characteristics and emissions 

control technologies with their LDT counterparts. However, in contrast to the largely 

gasoline-fueled LDT fleet, roughly half of the heavy-duty pickup and van fleet in the 

U.S. is diesel-fueled. This is an important consideration in setting emissions standards, 

as diesel engine emissions control strategies differ from those of gasoline engines.

As proposed, the key elements of the Tier 3 program for HDVs parallel those 

being adopted for passenger cars and LDTs, with adjustments in standard levels, emission 

test requirements, and implementation schedules appropriate to this sector. These key

elements include combined NMOG+NOX declining fleet average standards, a phase-in of 

PM standards, adoption of a new emissions test fuel for gasoline-fueled vehicles, 

extension of the regulatory useful life to 150,000 miles or 15 years (whichever occurs 

first), and a first-ever requirement for HDVs to meet standards over an SFTP drive cycle 

that addresses real-world driving modes not well-represented by the FTP cycles.

We are adopting the Class 2b and Class 3 fleet average NMOG+NOX standards 

shown in Table I-4, as proposed. The standards become more stringent in successive 

model years from 2018 to 2022, with voluntary standards made available in 2016 and 

2017, all of which are set at levels that match those of California’s LEV III program for 

these classes of vehicles. Each covered HDV sold by a manufacturer in each model year 

contributes to this fleet average based on the mg/mi NMOG+NOX standard level of the 

“bin” declared for it by the manufacturer, who chooses from a set of seven discrete Tier 3 

bins specified in the regulations. These bin standards then become the compliance 
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standards for the vehicle over its useful life, with some adjustment provided for in-use 

testing in the early model years of the program.

As proposed, manufacturers can also earn credits for fleet average NMOG+NOX

levels below the standard in any model year. Tier 3 credits that were previously banked, 

obtained from other manufacturers, or transferred across the Class 2b/Class 3 categories 

can be used to help demonstrate compliance. Unused credits expire after 5 model years. 

Manufacturers will also be allowed to carry forward deficits in their credit balance for up 

to 3 model years.

Table I-4 Tier 3 HDV Fleet Average FTP NMOG+NOX Standards (mg/mi)

Voluntary Required Program

Model 

Year 2016 2017 2018 2019 2020 2021 2022 and later

Class 2b 333 310 278 253 228 203 178

Class 3 548 508 451 400 349 298 247

 

We are adopting the proposed FTP PM standards of 8 mg/mi and 10 mg/mi for 

Class 2b and Class 3 HDVs, respectively, phasing in as an increasing percentage of a 

manufacturer’s sales per year. We are adopting the same phase-in schedule as for the 

light-duty sector during model years 2018-2019-2020-2021: 20-40-70-100 percent, 

respectively, and a more flexible but equivalent alternative PM phase-in is also being 

adopted. Tier 3 HDVs will also be subject to CO and formaldehyde exhaust emissions 

standards that are more stringent than the existing standards.

Finally, we are setting first-ever nationwide SFTP standards for HDVs to ensure a 

robust overall control program that precludes high off-FTP cycle emissions by having 

vehicle designers consider them in their choice of compliance strategies. As for lightduty vehicles, we are requiring that SFTP compliance be based on a weighted composite 

of measured emissions from testing over the FTP cycle, the SC03 cycle, and an 

aggressive driving cycle, with the latter tailored to various HDV sub-categories: the 

US06 cycle for most HDVs, the highway portion of the US06 cycle for low power-toweight Class 2b HDVs, and the LA-92 (or “Unified”) cycle for Class 3 HDVs. The 

SFTP standards are the same as those adopted for California LEV III vehicles, and apply 

to NMOG+NOX, PM, and CO emissions.

The HDV program outlined above and described in detail in Section IV.B is 

substantially what we proposed. Commenters generally supported the scope, stringency, 

and implementation phase-in of this program. However, some industry commenters 
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requested changes to some specific provisions of the proposal, and the program we are 

adopting reflects improvements we have made in response. These are: (1) a limited 

allowance for engine certification of Class 3 complete diesel vehicles to avoid a potential 

need for dual chassis- and engine-based certification and to better harmonize with LEV 

III, (2) relaxed interim in-use testing standards to facilitate a smooth transition to the Tier 

3 standards and to better harmonize with LEV III, (3) adoption of combined 

NMOG+NOx standards for the two highest (interim) bins, with a restriction placed on 

NOx levels in certification testing, to enhance the utility of these bins and to better 

harmonize with LEV III, and (4) a provision in the percent-of-sales phase-in alternative 

to allow manufacturers to exclude vehicle models that begin their 2019 model year 

production early in 2018, in order to provide four years of lead time. Commenters also 

requested relaxed standards for testing at high altitudes and changes to the credits 

program structure for generation of early credits and use of LEV III-based “vehicle 

emission credits”, but we did not adopt these for reasons explained in Section IV.B.

Overall, we expect the Tier 3 program we are adopting for HDVs to result in 

substantial reductions in harmful emissions from this large fleet of work trucks and vans. 

The fully-phased in Tier 3 standards levels for NMOG+NOX and PM are on the order of 

60 percent lower than the current standards that took full effect in the 2009 model year.

c. Evaporative Emission Standards

Gasoline vapor emissions from vehicle fuel systems occur when a vehicle is in 

operation, when it is parked, and when it is being refueled. These evaporative emissions, 

which occur on a daily basis from gasoline-powered vehicles, are primarily functions of 

temperature, fuel vapor pressure, and activity. EPA first instituted evaporative emission 

standards in the early 1970s to address emissions when vehicles are parked after being 

driven. These are commonly referred to as hot soak plus diurnal emissions. Over the 

subsequent years the test procedures have been modified and improved and the standards 

have become more numerically stringent. We have addressed emissions which arose 

from new fuel system designs by putting in place new requirements such as running loss 

emission standards and test procedure provisions to address permeation emissions. 

Subsequently standards were put in place to control refueling emissions from all classes 

of gasoline-powered motor vehicles up to 10,000 lbs GVWR. Evaporative and refueling 

emission control systems have been in place for most of these vehicles for many years. 

These controls have led to significant reductions, but evaporative and refueling emissions 

still constitute 30-40 percent of the summer on-highway mobile source hydrocarbon 

inventory. These fuel vapor emissions are ozone and PM precursors, and also contain air 

toxics such as benzene. 

To control evaporative emissions, EPA is establishing more stringent standards 

that will require covered vehicles to have essentially zero fuel vapor emissions in use. 

These include more stringent evaporative emissions standards, new test procedures, and a 

new fuel/evaporative system leak emission standard. The program also includes 

refueling emission standards for all complete heavy-duty gasoline vehicles (HDGVs) 
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over 10,000 lbs GVWR. EPA is including phase-in flexibilities as well as credit and 

allowance programs. The standards, harmonized with California’s “zero evap” standards, 

are designed to allow for a use of common technology in vehicle models sold throughout 

the U.S. The level of the standard remains above zero to account for nonfuel background 

emissions from the vehicle hardware.

Requirements to meet the Tier 3 evaporative emission regulations phase in over a 

six model year period. We are finalizing three options for the 2017 model year, but after 

that the sales percentage requirements are 60 percent for MYs 2018 and 2019, 80 percent 

for model years 2020 and 2021, and 100 percent for model years 2022 and later. In Table 

I-5 we present the Tier 3 evaporative hot soak plus diurnal emission standards by vehicle 

class. The standards are approximately a 50 percent reduction from the existing 

standards. To enhance flexibility and reduce costs, EPA is finalizing provisions that 

allow manufacturers to generate allowances through early certifications (basically before 

the 2017 model year) and to demonstrate compliance using averaging concepts. 

Manufacturers may comply on average within each of the four vehicle categories, but not 

across these categories. EPA is not making any changes to the existing light-duty

running loss or refueling emission standards, with the exception of the certification test 

fuel requirement discussed in Section I.B.2 below.

Table I-5 Tier 3 Evaporative Emission Standards (g/test)

Vehicle Class Highest Hot Soak + Diurnal Level

(over both 2-day and 3-day diurnal tests)

LDV, LDT1 0.300

LDT2 0.400

LDT3, LDT4, MDPV 0.500

HDGVs 0.600

Flexible Fuel Vehicles (FFVs) must meet the same evaporative emission 

standards as non-FFVs using Tier 3 emissions certification test fuel. However, FFVs 

must meet the refueling emission standards using 10 psi RVP fuel to account for 

emissions resulting from commingling with non-E85 blends that may be in the vehicle’s 

fuel tank.

EPA is establishing the canister bleed emission test procedure and emission 

standard to help ensure fuel vapor emissions are eliminated. Under this provision, 

manufacturers are required to measure diurnal emissions over the 2-day diurnal test 

procedure from just the fuel tank and the evaporative emission canister and comply with 

a 0.020 gram per test (g/test) standard for all LDVs, LDTs, and MDPVs, without 

averaging. The corresponding canister bleed test standard for HDGVs is 0.030 g/test. 

The Tier 3 evaporative emission standards will be phased in over a period of six model 

years between MY 2017 and MY 2022, with the leak test phasing in beginning in 2018.
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Data from in-use evaporative emissions testing indicates that vapor leaks from 

vehicle fuel/evaporative systems are found in the fleet and that even very small leaks 

have the potential to make significant contributions to the mobile source VOC inventory. 

To help address this issue, we are also adding a new standard and test procedure to 

control vapor leaks from vehicle fuel and vapor control systems. The standard will 

prohibit leaks with a cumulative equivalent diameter of 0.02 inches or greater. We are 

adding this simple and inexpensive test and emission standard to help ensure vehicles 

maintain zero fuel vapor emissions over their full useful life. New LDV, LDT, MDPV, 

and HDGV equal to or less than 14.000 lbs GVWR meeting the Tier 3 evaporative 

emission regulations are also required to meet the leak standard beginning in the 2018 

model year. Manufacturers must comply with the leak standard phase-in on the same 

percentage of sales schedule as that for the Tier 3 evaporative emission standards. 

Manufacturers will comply with the leak emission standard during certification and in 

use. The leak emission standard does not apply to HDGVs above 14,000 lbs GVWR.

EPA is also establishing new refueling emission control requirements for all 

complete HDGVs equal to or less than 14,000 lbs GVWR (i.e., Class 2b/3 HDGVs), 

starting in the 2018 model year, and for all larger complete HDGVs by the 2022 model 

year. The existing refueling emission control requirements apply to complete Class 2b 

HDGVs, and EPA is extending those requirements to other complete HDGVs, since the 

fuel and evaporative control systems on these vehicles are very similar to those on their 

lighter-weight Class 2b counterparts.

 

d. Onboard Diagnostic Systems (OBD)

EPA and CARB both have OBD regulations applicable to the vehicle classes 

covered by the Tier 3 emission standards. In the past the requirements have been very

similar, so most manufacturers have met CARB OBD requirements and, as permitted in 

our regulations, EPA has generally accepted compliance with CARB’s OBD 

requirements as satisfying EPA’s OBD requirements. Over the past several years CARB 

has upgraded its requirements to help improve the effectiveness of OBD in ensuring good 

in-use exhaust and evaporative system emissions performance. We have reviewed these 

provisions and agree with CARB that these revisions will help to improve in-use 

emissions performance, while at the same time harmonizing with the CARB program. 

Toward that end, we are adopting and incorporating by reference the current CARB OBD 

regulations, effective for the 2017 MY, with a few minor differences including phase-in 

flexibility provisions and specific additions to enhance the implementation of the leak 

standard. EPA is retaining the provision that certifying with CARB’s program would 

permit manufacturers to seek a separate EPA certificate on that basis. 
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e. Emissions Test Fuel

As described above, after reassessing market trends and considering comments, 

EPA is finalizing E10 as the ethanol blend level in emissions test gasoline for Tier 3 

light-duty and heavy-duty gasoline vehicles. We will continue to monitor the in-use 

gasoline supply and based on such review may initiate rulemaking action to revise the 

specifications for emissions test fuel to include a higher ethanol blend level. EPA is also 

making additional changes that are consistent with CARB’s LEV III emissions test fuel 

specifications, including new specifications for octane, distillation temperatures, 

aromatics, olefins, sulfur and benzene. (See Section IV.F below for a detailed discussion 

of all the revised emission test fuel parameters.) 

As discussed in Sections IV.A.7.d (tailpipe emission testing) and IV.C.5.b 

(evaporative emission testing), we are requiring certification of all Tier 3 light-duty and 

chassis-certified heavy-duty gasoline vehicles on federal E10 test fuel. The new test fuel 

specifications will apply to new vehicle certification, assembly line, and in-use testing. 

With a change in the ethanol content of the test fuel, EPA also needed to consider 

whether a change is warranted in the volatility of the test fuel, typically expressed as 

pounds per square inch (psi) Reid Vapor Pressure (RVP). As discussed in detail in 

Section IV.F below, after considering several technical and policy implications as well as 

stakeholder comments, EPA has concluded that the most appropriate approach is to 

maintain an RVP of 9 psi for the E10 certification fuel at this time. 

In addition to finalizing a new E10 emissions test fuel, we are also finalizing 

detailed specifications for the E85 emissions test fuel used for flexible fuel vehicle (FFV) 

certification, as discussed in Section IV.F.3.15 This will resolve uncertainty and 

confusion in the certification of FFVs designed to operate on ethanol levels up to 83 

percent. Furthermore, we allow vehicle manufacturers to request approval for an 

alternative certification fuel such as a high-octane 30 percent ethanol by volume blend 

(E30) for vehicles that may be optimized for such fuel. 

f. Fuel Standards

Under the Tier 3 fuel program, gasoline must contain no more than 10 ppm sulfur 

on an annual average basis beginning January 1, 2017. Similar to the Tier 2 gasoline 

program, the Tier 3 program will apply to gasoline in the U.S. and the U.S. territories of 

Puerto Rico and the Virgin Islands, excluding California. The program will result in 

gasoline that contains, on average, two-thirds less sulfur than it does today. In addition, 

following discussions with numerous refiners and other segments of the fuel market (e.g., 

 

15 Flexible fuel vehicles are currently required to meet emissions certification requirements using both E0 

and E85 test fuels. However, there were no detailed regulatory specifications regarding the composition of 

E85 test fuels before those finalized today.
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pipelines, terminals, marketers, ethanol industry representatives, transmix processors, 

additive manufacturers, etc.), the Tier 3 fuel program contains considerable flexibility to 

ease both initial and long-term implementation of the program. The program that we are 

finalizing today includes an averaging, banking, and trading (ABT) program that allows 

refiners and importers to spread out their investments over nearly a 6 year period through 

the use of an early credit program and then rely on ongoing nationwide averaging to meet 

the 10 ppm sulfur standard. In addition there is a three-year delay for small refiners and 

“small volume refineries”. As a result of the early credit program, we anticipate 

considerable reductions in gasoline sulfur levels prior to 2017, with a complete transition 

to the 10 ppm average occurring by January 1, 2020. For more information on the 

gasoline sulfur program flexibilities, refer to Section V.E. 

Under today’s Tier 3 gasoline sulfur program, we are maintaining the current 80 

ppm refinery gate and 95 ppm downstream per-gallon caps. We also evaluated and 

sought comment on the potential of lowering the per-gallon caps. While there are 

advantages and disadvantages with each of the sulfur cap options that we proposed, we 

believe that retaining the current Tier 2 sulfur caps is prudent at this time, as explained in 

more detail in Section V.C. Further, the stringency of the 10 ppm annual average 

standard will result in reduced gasoline sulfur levels nationwide. Today’s program 

requires that manufacturers of gasoline additives that are used downstream of the refinery

at less than 1 volume percent must limit the sulfur contribution to the finished gasoline 

from the use of their additive to less than 3 ppm when the additive is used at the 

maximum recommended treatment rate (see Section V.C.2). This requirement will 

preclude the unnecessary use of high sulfur content additives in gasoline.

The vehicle emissions standards finalized today are fuel-neutral (i.e., they are 

applicable regardless of the type of fuel that the vehicle is designed to use). There 

currently are no sulfur standards for the fuel used in compressed natural gas (CNG) and 

liquid propane gas (LPG) vehicles. We requested comment on whether it is necessary for 

EPA to establish sulfur standards for CNG and LPG to enable them meeting more 

stringent vehicle emissions standards. EPA is deferring finalizing in-use sulfur 

requirements for CNG/LPG in this final rule to provide additional time to work with 

stakeholders to collect data on current CNG/LPG sulfur content, to determine whether 

additional control of in-use CNG/LPG sulfur content is needed, and to evaluate the 

feasibility and costs associated with potential additional sulfur controls (see Section V.J). 

Given that the information provided suggests that CNG/LPG sulfur levels tend to be low 

already, the vehicle emissions standards finalized today will apply to CNG/LPG vehicles 

in addition to vehicles fueled on gasoline, diesel fuel, or any other fuel. The sulfur 

content of highway diesel fuel is already required to meet a 15 ppm sulfur cap, which is 

sufficient for diesel fuel vehicles to meet the Tier 3 emissions standards.

As the number of flex-fuel vehicles (FFVs) in the in-use fleet increases, it is 

becoming increasingly important that all fuels used in FFVs, not just gasoline, meet fuel 

quality standards. A lack of clarity regarding the standards that apply to fuels used in 

FFVs could also act to impede the further expansion of ethanol blended fuels with 
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concentrations greater than 15 volume percent, which is important to satisfying the 

requirements of the RFS2 program. Hence, we sought comment on appropriate 

regulatory mechanisms to implement in-use quality standards for E51-83 and E16-50 in 

the Tier 3 proposal. Additional work is needed on some issues that could not be 

accommodated within the timeline for this Tier 3 final rule. Therefore, we are choosing 

not to finalize these provisions at this time. We intend to finalize in-use fuel quality

standards for E51-83 and perhaps E16-50 as well in a follow-up final rule.

g. Regulatory Streamlining and Technical Amendments

This action also includes a number of items to help streamline the in-use fuels 

regulations at 40 CFR parts 79 and 80. The majority of these items involve clarifying 

vague or inconsistent language, removal or updating of outdated provisions, and 

decreasing in frequency and/or volume of reporting burden where data are no longer 

needed or are redundant with other EPA fuels programs. In general, we believe that these 

changes will reduce the burden on industry and allow the standards and resulting 

environmental benefits to be achieved as early as possible with no expected loss in 

environmental control. In some cases, these regulatory streamlining items are nonsubstantive amendments that correct minor errors or inconsistencies in the regulations.

The regulatory streamlining items that we are finalizing for the in-use fuels 

regulations are changes that we believe are straightforward and should be made quickly. 

This action also includes a variety of technical amendments to certificationrelated requirements for engine and vehicle emission standards; adjusting the fuel 

economy label provisions to correspond to the new Tier 3 standards, removing obsolete 

regulatory text, and making several minor corrections and clarifications. 

Please refer to Section VI for a complete discussion of technical amendments and 

regulatory streamlining provisions and issues.

C. What Will the Impacts of the Standards Be?

The final Tier 3 vehicle and fuel standards together will reduce dramatically 

emissions of NOX, VOC, PM2.5, and air toxics. The gasoline sulfur standards, which will 

take effect in 2017, will provide large immediate reductions in emissions from existing 

gasoline vehicles and engines. NOX emissions are projected to be reduced by about 

260,000 tons, or about 10 percent of emissions from on-highway vehicles, in 2018, and 

these emission reductions will increase over time as newer vehicles become a larger 

percentage of the fleet. In 2030, when 70 percent of the miles travelled are projected to 

be from vehicles that meet the fully phased-in Tier 3 standards, we expect the NOX and 

VOC emissions to be reduced by about 330,000 tons and 170,000 tons, respectively, or 

25 percent and 16 percent of emissions from on-highway vehicles compared to their 2030 

levels without the Tier 3 program. Emissions of CO are projected to decrease by almost 

3.5 million tons, or 24 percent of emissions from on-highway vehicles. Emissions of 
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many air toxics will also be reduced, including benzene, 1,3-butadiene, acetaldehyde, 

formaldehyde, acrolein and ethanol, with reductions projected to range from 10 to nearly

30 percent of national emissions from on-highway vehicles. We expect these reductions 

to continue beyond 2030 as more of the fleet continues to turn over to Tier 3 vehicles; for 

example, by 2050, when nearly all of the fleet will have turned over to vehicles meeting 

the fully phased-in Tier 3 standards, we estimate the Tier 3 program will reduce onhighway emissions of NOX and VOC nearly 31 percent from the level of emissions 

projected without Tier 3 controls.16 

These reductions in emissions of NOX, VOC, PM2.5 and air toxics from the Tier 3 

standards are projected to lead to significant decreases in ambient concentrations of 

ozone, PM2.5 and air toxics (including notable nationwide reductions in benzene 

concentrations) by 2030, and will immediately reduce ozone in 2017 when the sulfur 

controls take effect. Additional information on the emission and air quality impacts of 

the final Tier 3 program is presented in Sections III.B and C. 

Exposure to ambient concentrations of ozone, PM2.5, and air toxics is linked to 

adverse human health impacts such as premature deaths as well as other important public 

health and environmental effects (see Section II.B). The final Tier 3 standards are 

expected to reduce these adverse impacts and yield significant benefits, including those 

we can monetize and those we are unable to quantify. We estimate that by 2030, the 

emission reductions of the Tier 3 standards will annually prevent between 660 and 1,500 

PM-related premature deaths, between 110 and 500 ozone-related premature deaths, 

81,000 work days lost, 210,000 school absence days, and approximately 1.1 million 

minor restricted-activity days. The estimated annual monetized health benefits of the 

Tier 3 standards in 2030 (2011$) is between $7.4 and $19 billion, assuming a 3-percent 

discount rate (or between $6.7 billion and $18 billion assuming a 7-percent discount 

rate). We project the final fuel standards to cost on average 0.65 cent (i.e., less than a 

penny) per gallon of gasoline, and the final vehicle standards to have an average cost that 

increases in proportion to the increase in stringency during the phase-in period, from $28 

per vehicle in 2017 to $72 per vehicle in 2025, when the standards are fully phased in. 

We estimate the annual cost of the overall program in 2030 will be approximately $1.5 

billion, and the 2030 benefits will be between 4.5 and 13 times the costs of the program. 

The estimated benefits in Table I-6 include all of the human health impacts we are 

able to quantify and monetize at this time. However, the full complement of human 

health and welfare effects associated with PM, ozone and air toxics remain unquantified 

because of current limitations in methods and/or available data. As a result, the health 

benefits quantified in this section are likely underestimates of the total benefits 

attributable to the final standards. See Sections VII and VIII for detailed descriptions of 

the costs and benefits of this action. 

 

16 To estimate the benefits of the final Tier 3 rule, we performed air quality modeling for the year 2030. 
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Table I-6 Summary of Estimated Annual Benefits and Costs Associated with the 

Final Tier 3 Program (Billions, 2011$)a

Description 2030

Vehicle Program Costs

Fuels Program Costs

Total Estimated Costsb

$0.76

$0.70

$1.5

Total Estimated Health Benefitsc,d,e,f

 3 percent discount rate

 7 percent discount rate

$7.4 - $19

$6.7 - $18

Annual Net Benefits (Total Benefits – Total Costs)

 3 percent discount rate

 7 percent discount rate

$5.9 - $18

$5.2 - $17

Notes:

a All estimates represent annual benefits and costs anticipated for the year 2030. Totals are rounded to two 

significant digits and may not sum due to rounding.

b The calculation of annual costs does not require amortization of costs over time. Therefore, the estimates 

of annual cost do not include a discount rate or rate of return assumption (see Section VII of the preamble 

for more information on vehicle and fuel costs).

c Total includes ozone and PM2.5 estimated benefits. Range was developed by adding the estimate from the 

Bell et al., 2004 ozone premature mortality function to PM2.5-related premature mortality derived from the 

American Cancer Society cohort study (Krewski et al., 2009) for the low estimate and ozone premature 

mortality derived from the Levy et al., 2005 study to PM2.5-related premature mortality derived from the 

Six-Cities (Lepeule et al., 2012) study for the high estimate.

d Annual benefits analysis results reflect the use of a 3 percent and 7 percent discount rate in the valuation 

of premature mortality and nonfatal myocardial infarctions, consistent with EPA and OMB guidelines for 

preparing economic analyses. 

e Valuation of premature mortality based on long-term PM exposure assumes discounting over the SAB 

recommended 20-year segmented lag structure described in the Regulatory Impact Analysis for the 2012 

PM National Ambient Air Quality Standards (December, 2012). 

f Not all possible benefits are quantified and monetized in this analysis; the total monetized benefits 

presented here may therefore be underestimated. Potential benefit categories that have not been quantified 

and monetized, due to current limitations in methods and/or data availability, are listed in Table VIII-2. For 

example, we have not quantified a number of known or suspected health and welfare effects linked with 

reductions in ozone and PM (e.g., reductions in heart rate variability, reduced material damage to structures 

and cultural monuments, and reduced eutrophication in coastal areas). We are also unable to quantify 

health and welfare benefits associated with reductions in air toxics.

II. Why Is EPA Taking this Action? 

The Clean Air Act authorizes EPA to establish emissions standards for motor 

vehicles to address air pollution that may reasonably be anticipated to endanger public 

health or welfare. EPA also has authority to establish fuel controls to address such air 

pollution. These statutory requirements are described in Section II.A.

Emissions from motor vehicles and their fuels contribute to ambient levels of 

ozone, PM, NO2, sulfur dioxide (SO2) and CO, which are all pollutants for which EPA 

has established health-based NAAQS. These pollutants are linked with respiratory and/or 
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cardiovascular problems and other adverse health impacts leading to increased 

medication use, hospital admissions, emergency department visits, and premature 

mortality. Over 149 million people currently live in areas designated nonattainment for 

one or more of the current NAAQS for ozone, PM2.5, PM10, and SO2.

17

 

Motor vehicles also emit air toxics, and the most recent available data indicate 

that the majority of Americans continue to be exposed to ambient concentrations of air 

toxics at levels which have the potential to cause adverse health effects, including cancer, 

immune system damage, and neurological, reproductive, developmental, respiratory, and 

other health problems.18 A more detailed discussion of the health and environmental 

effects of these pollutants is included in Section II.B. 

Cars and light trucks also continue to be a significant contributor to air pollution 

directly near roads, with gasoline vehicles accounting for more than 50 percent of nearroad concentrations of some criteria and toxic pollutants.19

 More than 50 million people 

live, work, or go to school in close proximity to high-traffic roadways, and the average 

American spends more than one hour traveling each day, with over 80 percent of daily

trips occurring by personal vehicle.20,21,22,23,24 Exposure to traffic-related pollutants has 

been linked with adverse health impacts such as respiratory problems (particularly in 

asthmatic children) and cardiovascular problems. 

In the absence of additional controls such as Tier 3 standards, many areas will 

continue to have ambient ozone and PM2.5 concentrations exceeding the NAAQS in the 

future. States and local areas are required to adopt control measures to attain the NAAQS 

and, once attained, to demonstrate that control measures are in place sufficient to 

 

17 Data come from Summary Nonattainment Area Population Exposure Report, current as of December 5, 

2013 at: http://www.epa.gov/oar/oaqps/greenbk/popexp.html and contained in Docket EPA-HQ-OAR2011-0135.

18 U.S. EPA. (2011) Summary of Results for the 2005 National-Scale Assessment. 

www.epa.gov/ttn/atw/nata2005/05pdf/sum_results.pdf.

19 For example, see Fujita, E.M; Campbell, D.E.; Zielinska, B.; Arnott, W.P.; Chow, J.C. (2011) 

Concentrations of Air Toxics in Motor Vehicle-Dominated Environments. Health Effects Institute 

Research Report 156. Available at http://www.healtheffects.org

20 Rowangould, G.M. (2013) A census of the US near-roadway population: public health and 

environmental justice considerations. Transportation Research Part D 25: 59-67.

21 U.S. Census Bureau (2011). Current Housing Reports, Series H150/09, American Housing Survey for the 

United States: 2009. U.S. Government Printing Office, Washington, DC. Available at 

http://www.census.gov/hhes/www/housing/ahs/ahs09/ahs09.html

22 Drago, R.(2011). Secondary activities in the 2006 American Time Use Survey. U.S. Bureau of Labor 

Statistics Working Paper 446. Available at http://www.bls.gov

23 U.S. Department of Transportation, Bureau of Transportation Statistics. (2003) National Household 

Travel Survey 2001 Highlights Report. Government Printing Office, Washington, DC. Available at 

http://www.bts.gov/publications/highlights_of_the_2001_national_household_travel_survey/

24 Santos, A.; McGuckin, N, Yukiko Nakamoto, H.; Gray, D.; Liss, S. (2011) Summary of Travel Trends: 

2009 National Household Travel Survey. Federal Highway Administration report no FHWA-PL-11-022. 

Available at http://nhts.ornl.gov/publications.shtml.
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maintain the NAAQS for ten years (and eight years later, a similar demonstration is 

required for another ten-year period). The Tier 3 standards will be a critical part of many

areas’ strategies to attain and maintain the NAAQS. Maintaining the NAAQS has been 

challenging for some areas in the past, particularly those where high population growth 

rates lead to significant annual increases in vehicle trips and vehicle miles traveled. Our 

air quality modeling for this final rule, which is described in more detail in Section III.C, 

projects that in 2018 a significant number of counties outside CA will be within 10 

percent of the 2008 ozone NAAQS, in the absence of additional controls. These counties 

in particular will benefit from the Tier 3 standards as they work to ensure long-term 

maintenance of the NAAQS. 

Section III provides more detail on how we expect this action will reduce motor 

vehicle emissions and ambient levels of pollution. We project that the Tier 3 program 

will meaningfully reduce ozone concentrations as early as 2017 (the first year of the 

program), and even more significantly in 2030. The estimated reductions are of 

significant enough magnitude to bring ozone levels in some counties from above the 

standard to below the standard, even without any additional controls. We also project 

that the Tier 3 standards will reduce ambient PM2.5 concentrations. 

Without this action to reduce nationwide motor vehicle emissions, areas would 

have to adopt other measures to reduce emissions from other sources under their state or 

local authority. Few other measures exist for providing multi-pollutant reductions of the 

same magnitude and cost-effectiveness as those expected from the Tier 3 standards. 

Furthermore, most states do not have the authority to lower the sulfur in gasoline, which 

is needed to immediately reduce emissions from the existing fleet and also enable new 

vehicles to meet the Tier 3 emissions standards throughout their useful life. 

The projected reductions in ambient ozone and PM2.5 that will result from the Tier 

3 standards will provide significant health benefits. We estimate that by 2030, the 

standards will annually prevent between 660 and 1,500 PM-related premature deaths, 

between 110 and 500 ozone-related premature deaths, 81,000 work days lost, 210,000 

school absence days, and approximately 1.1 million minor restricted-activity days (see 

Section VIII for more details). This action will also reduce air toxics; for example, we 

project that in 2030, the Tier 3 standards will decrease ambient benzene concentrations 

by 10 - 25 percent in some urban areas. Furthermore, the Tier 3 standards will reduce 

traffic-associated pollution near major roads.

EPA is finalizing Tier 3 vehicle and fuel standards as part of a comprehensive 

nationwide program for regulating all types of air pollution from motor vehicles. EPA 

recently finalized standards to reduce GHG emissions from light-duty vehicles, starting 

with model year 2017.25 The Tier 3 standards in this final rule, which address non-

 

25 77 FR 62623 (October 15, 2012).
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GHGs, will be implemented on the same timeframe, thus allowing manufacturers to 

optimize their vehicle redesigns over both sets of standards. Furthermore, the Tier 3 

vehicle and fuel standards are also closely aligned with California’s LEV III program, in 

such a way that manufacturers will be able to design a single vehicle for nationwide sales. 

This reduces the cost of compliance for auto manufacturers.

This Tier 3 rulemaking responds to the President’s request in his May 2010 

memorandum for EPA to review the adequacy of its existing non-GHG standards for new 

motor vehicles and fuels, and to promulgate new standards, if necessary, as part of a 

comprehensive approach to regulating motor vehicles.26 Based on our review, we have 

concluded that improved vehicle technology, combined with lower sulfur gasoline, make 

it feasible and cost-effective to reduce emissions well below the current Tier 2 levels. 

These emission reductions are necessary to reduce air pollution that is (and projected to 

continue to be) at levels that endanger public health and welfare.

A. Basis for Action under the Clean Air Act

1. Clean Air Act Section 202

We are setting motor vehicle emission standards under the authority of section 

202 of the Clean Air Act. Section 202(a) provides EPA with general authority to 

prescribe vehicle standards, subject to any specific limitations elsewhere in the Act. EPA 

is setting standards for larger light-duty trucks and MDPVs under the general authority of 

section 202(a)(1) and under section 202(a)(3), which requires that standards applicable to 

emissions of hydrocarbons, NOX, CO and PM from heavy-duty vehicles27 reflect the 

greatest degree of emission reduction available for the model year to which such 

standards apply, giving appropriate consideration to cost, energy, and safety. In addition, 

section 202(k) provides EPA with authority to issue and revise regulations applicable to 

evaporative emissions of hydrocarbons from all gasoline-fueled motor vehicles during: 

(1) operation, and (2) over 2 or more days of nonuse; under ozone-prone summertime 

conditions. Regulations under section 202(k) shall take effect as expeditiously as possible 

and shall require the greatest degree of emission reduction achievable by means 

reasonably expected to be available for production during any model year to which the 

regulations apply, giving appropriate consideration to fuel volatility, and to cost, energy, 

and safety factors associated with the application of the appropriate technology. Further, 

section 206 and in particular section 206(d) of the Clean Air Act authorizes EPA to 

 

26 The Presidential Memorandum is found at: http://www.whitehouse.gov/the-press-office/presidentialmemorandum-regarding-fuel-efficiency-standards.

27 LDTs that have gross vehicle weight ratings above 6000 lbs and all MDPVs are considered ‘‘heavy-duty 

vehicles’’ under the CAA. See section 202(b)(3)(C). For regulatory purposes, we generally refer to those 

LDTs which are above 6000 lbs GVWR and at or below 8500 lbs GVWR as ‘‘heavy light-duty trucks’’ 

made up of LDT3s and LDT4s, and we have defined MDPVs primarily as vehicles between 8500 and 

10000 lbs GVWR designed primarily for the transportation of persons. See 40 CFR 86.1803-01
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establish methods and procedures for testing whether a motor vehicle or motor vehicle 

engine conforms with section 202 requirements.

2. Clean Air Act Section 211

We are adopting gasoline sulfur controls pursuant to our authority under section 

211(c)(1) of the CAA. This section allows EPA to establish a fuel control if at least one 

of the following two criteria is met: (1) The emission products of the fuel cause or 

contribute to air pollution which may reasonably be anticipated to endanger public health 

or welfare; or (2) the emission products of the fuel will impair to a significant degree the 

performance of any emissions control device or system which is either in general use or 

which the Administrator finds has been developed to a point where in a reasonable time it 

will be in general use were the fuel control to be adopted. We are finalizing gasoline 

sulfur controls based on both of these criteria. Under the first criterion, we believe that 

gasoline with current levels of sulfur contributes to ambient levels of air pollution that 

endanger public health and welfare, as described in Section II.B. Under the second 

criterion, we believe that gasoline sulfur impairs the emissions control systems of 

vehicles, as discussed in Section III.A.2. 

B. Overview of Public Health Impacts of Motor Vehicles and Fuels 

Motor vehicles emit pollutants that contribute to ambient concentrations of ozone, 

PM, NO2, SO2, CO, and air toxics. Motor vehicles are significant contributors to 

emissions of VOC and NOX, which contribute to the formation of both ozone and PM2.5. 

Over 149 million people currently live in counties designated nonattainment for one or 

more of the NAAQS, and this figure does not include the people living in areas with a 

risk of exceeding the NAAQS in the future.28 The majority of Americans continue to be 

exposed to ambient concentrations of air toxics at levels which have the potential to cause 

adverse health effects.29 In addition, populations who live, work, or attend school near 

major roads experience elevated exposure concentrations to a wide range of air 

pollutants.30

EPA has already adopted many emission control programs that are expected to 

reduce ambient pollution concentrations. As a result of these programs, the number of 

areas that continue to violate the ozone and PM2.5 NAAQS or have high levels of air 

toxics is expected to continue to decrease. However, the baseline air quality modeling 

 

28 Data come from Summary Nonattainment Area Population Exposure Report, current as of December 5, 

2013 at: http://www.epa.gov/oar/oaqps/greenbk/popexp.html and contained in Docket EPA-HQ-OAR2011-0135.

29 U.S. EPA. (2011) Summary of Results for the 2005 National-Scale Assessment. 

www.epa.gov/ttn/atw/nata2005/05pdf/sum_results.pdf. 

30

 Health Effects Institute Panel on the Health Effects of Traffic-Related Air Pollution. (2010) Trafficrelated air pollution: a critical review of the literature on emissions, exposure, and health effects. HEI 

Special Report 17. Available at http://www.healtheffects.org] 
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completed for this rule predicts that without additional controls there will continue to be a 

need for reductions in ozone, PM2.5 and air toxics concentrations in some locations in the 

future. Section III.C of this preamble presents the air quality modeling results for this 

action. 

1. Ozone 

a. Background

Ground-level ozone pollution is typically formed through reactions involving 

VOC and NOX in the lower atmosphere in the presence of sunlight. These pollutants, 

often referred to as ozone precursors, are emitted by many types of pollution sources, 

such as highway and nonroad motor vehicles and engines, power plants, chemical plants, 

refineries, makers of consumer and commercial products, industrial facilities, and smaller 

area sources.

The science of ozone formation, transport, and accumulation is complex. 

Ground-level ozone is produced and destroyed in a cyclical set of chemical reactions, 

many of which are sensitive to temperature and sunlight. When ambient temperatures 

and sunlight levels remain high for several days and the air is relatively stagnant, ozone 

and its precursors can build up and result in more ozone than typically occurs on a single 

high-temperature day. Ozone and its precursors can be transported hundreds of miles 

downwind from precursor emissions, resulting in elevated ozone levels even in areas with 

low local VOC or NOX emissions.

b. Health Effects of Ozone

This section provides a summary of the health effects associated with exposure to 

ambient concentrations of ozone.31 The information in this section is based on the 

information and conclusions in the February 2013 Integrated Science Assessment for 

Ozone (Ozone ISA) prepared by EPA’s Office of Research and Development (ORD).32 

The Ozone ISA concludes that human exposures to ambient concentrations of ozone are 

associated with a number of adverse health effects and characterizes the weight of 

evidence for these health effects. 33 The discussion below highlights the Ozone ISA’s 

 

31

 Human exposure to ozone varies over time due to changes in ambient ozone concentration and because 

people move between locations which have notable different ozone concentrations. Also, the amount of 

ozone delivered to the lung is not only influenced by the ambient concentrations but also by the individuals 

breathing route and rate.

32

 U.S. EPA. Integrated Science Assessment of Ozone and Related Photochemical Oxidants (Final Report). 

U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-10/076F, 2013. The ISA is available 

at http://cfpub.epa.gov/ncea/isa/recordisplay.cfm?deid=247492#Download

33 The ISA evaluates evidence and draws conclusions on the causal relationship between relevant pollutant 

exposures and health effects, assigning one of five “weight of evidence” determinations: causal 

relationship, likely to be a causal relationship, suggestive of a causal relationship, inadequate to infer a 
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conclusions pertaining to health effects associated with both short-term and long-term 

periods of exposure to ozone.

For short-term exposure to ozone, the Ozone ISA concludes that respiratory

effects, including lung function decrements, pulmonary inflammation, exacerbation of 

asthma, respiratory-related hospital admissions, and mortality, are causally associated 

with ozone exposure. It also concludes that cardiovascular effects, including decreased 

cardiac function and increased vascular disease, and total mortality are likely to be 

causally associated with short-term exposure to ozone and that evidence is suggestive of 

a causal relationship between central nervous system effects and short-term exposure to 

ozone. 

For long-term exposure to ozone, the Ozone ISA concludes that respiratory

effects, including new onset asthma, pulmonary inflammation and injury, are likely to be 

a causally related with ozone exposure. The Ozone ISA characterizes the evidence as 

suggestive of a causal relationship for associations between long-term ozone exposure 

and cardiovascular effects, reproductive and developmental effects, central nervous 

system effects and total mortality. The evidence is inadequate to infer a causal 

relationship between chronic ozone exposure and increased risk of lung cancer.

Finally, interindividual variation in human responses to ozone exposure can result 

in some groups being at increased risk for detrimental effects in response to exposure. 

The Ozone ISA identified several groups that are at increased risk for ozone-related 

health effects. These groups are people with asthma, children and older adults, 

individuals with reduced intake of certain nutrients (i.e., Vitamins C and E), outdoor 

workers, and individuals having certain genetic variants related to oxidative metabolism 

or inflammation. Ozone exposure during childhood can have lasting effects through 

adulthood. Such effects include altered function of the respiratory and immune systems. 

Children absorb higher doses (normalized to lung surface area) of ambient ozone, 

compared to adults, due to their increased time spent outdoors, higher ventilation rates 

relative to body size, and a tendency to breathe a greater fraction of air through the 

mouth. Children also have a higher asthma prevalence compared to adults. Additional 

children’s vulnerability and susceptibility factors are listed in Section XII.G.

c. Current and Projected Concentrations of Ozone 

Concentrations that exceed the level of the ozone NAAQS occur in many parts of 

the country, including major population centers such as Atlanta, Baltimore, Chicago, 

Dallas, Houston, New York, Philadelphia, and Washington, D.C. In addition, our 

modeling without the Tier 3 controls projects that in the future we will continue to have 

many counties that will have ambient ozone concentrations above the level of the 

 

causal relationship, and not likely to be a causal relationship. For more information on these levels of 

evidence, please refer to Table II in the Preamble of the ISA. 
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NAAQS (see Section III.C.1). States will need to meet the standard in the 2015-2032 

time frame for the 2008 ozone NAAQS. The emission reductions and significant ambient 

ozone improvements from this rule, which will take effect starting in 2017, will be 

helpful to states as they work to attain and maintain the ozone NAAQS.

The primary and secondary NAAQS for ozone are 8-hour standards with a level 

of 0.075 ppm. The most recent revision to the ozone standards was in 2008; the previous 

8-hour ozone standards, set in 1997, had a level of 0.08 ppm. In 2004, the U.S. EPA 

designated nonattainment areas for the 1997 8-hour ozone NAAQS.34,35 As of December 

5, 2013, there were 39 ozone nonattainment areas for the 1997 ozone NAAQS composed 

of 216 full or partial counties with a total population of over 112 million. Nonattainment 

designations for the 2008 ozone standard were finalized on April 30, 2012 and May 31, 

2012.36 As of December 5, 2013, there were 46 ozone nonattainment areas for the 2008 

ozone NAAQS, composed of 227 full or partial counties, with a population of over 123 

million. As of December 5, 2013, over 135 million people are living in ozone 

nonattainment areas.37 

States with ozone nonattainment areas are required to take action to bring those 

areas into attainment. The attainment date assigned to an ozone nonattainment area is 

based on the area’s classification. Most ozone nonattainment areas were required to 

attain the 1997 8-hour ozone NAAQS in the 2007 to 2013 time frame and then to 

maintain it thereafter.38 The attainment dates for areas designated nonattainment for the 

2008 8-hour ozone NAAQS are in the 2015 to 2032 timeframe, depending on the severity 

of the problem in each area. In addition, EPA is currently working on a review of the 

ozone NAAQS. If EPA revises the ozone standards pursuant to that review, the 

attainment dates associated with areas designated nonattainment for that NAAQS would 

be 5 or more years after the final rule is promulgated, depending on the severity of the 

problem in each area. 

EPA has already adopted many emission control programs that are expected to 

reduce ambient ozone levels. As a result of these and other federal, state and local 

 

34 69 FR 23858 (April 30, 2004).

35 A nonattainment area is defined in the Clean Air Act (CAA) as an area that is violating an ambient 

standard or is contributing to a nearby area that is violating the standard.

36 77FR 30088 (May 21, 2012) and 77 FR 34221 (June 11, 2012).

37 The 135 million total is calculated by summing, without double counting, the 1997 and 2008 ozone 

nonattainment populations contained in the Summary Nonattainment Area Population Exposure report 

(http://www.epa.gov/oar/oaqps/greenbk/popexp.html). If there is a population associated with both the 

1997 and 2008 nonattainment areas, and they are not the same, then the larger of the two populations is 

included in the sum.

38 The Los Angeles South Coast Air Basin 8-hour ozone nonattainment area and the San Joaquin Valley Air 

Basin 8-hour ozone nonattainment area are designated as Extreme and will have to attain before June 15, 

2024. The Sacramento, Coachella Valley, Western Mojave and Houston 8-hour ozone nonattainment areas 

are designated as Severe and will have to attain by June 15, 2019. 
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programs, 8-hour ozone levels are expected to improve in the future. However, even 

with the implementation of all current state and federal regulations, there are projected to 

be counties violating the ozone NAAQS well into the future. Thus additional federal 

control programs, such as Tier 3, can assist areas with attainment dates in 2018 and 

beyond in attaining the NAAQS as expeditiously as practicable and may relieve areas 

with already stringent local regulations from some of the burden associated with adopting 

additional local controls.

2. Particulate Matter

a. Background

Particulate matter is a highly complex mixture of solid particles and liquid 

droplets distributed among numerous atmospheric gases which interact with solid and 

liquid phases. Particles range in size from those smaller than 1 nanometer (10-9 meter) to 

over 100 micrometer (μm, or 10-6 meter) in diameter (for reference, a typical strand of 

human hair is 70 μm in diameter and a grain of salt is about 100 μm). Atmospheric 

particles can be grouped into several classes according to their aerodynamic and physical 

sizes, including ultrafine particles (<0.1 μm), accumulation mode or ‘fine’ particles (<1 

to 3 μm), and coarse particles (>1 to 3 μm).39 For regulatory purposes, fine particles are 

measured as PM2.5 and inhalable or thoracic coarse particles are measured as PM10-2.5, 

corresponding to their size (diameter) range in micrometers. The EPA currently has 

standards that measure PM2.5 and PM10.

40

 

Particles span many sizes and shapes and may consist of hundreds of different 

chemicals. Particles are emitted directly from sources and are also formed through 

atmospheric chemical reactions; the former are often referred to as “primary” particles, 

and the latter as “secondary” particles. Particle concentration and composition varies by 

time of year and location, and in addition to differences in source emissions, is affected 

by several weather-related factors, such as temperature, clouds, humidity, and wind. A 

further layer of complexity comes from particles’ ability to shift between solid/liquid and 

gaseous phases, which is influenced by concentration and meteorology, especially 

temperature. 

Fine particles are produced primarily by combustion processes and by

transformations of gaseous emissions (e.g., sulfur oxides (SOX), oxides of nitrogen, and 

volatile organic compounds (VOC)) in the atmosphere. The chemical and physical 

 

39 U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. 

Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F. Figure 3-1.

40 Regulatory definitions of PM size fractions, and information on reference and equivalent methods for 

measuring PM in ambient air, are provided in 40 CFR Parts 50, 53, and 58. With regard to national 

ambient air quality standards (NAAQS) which provide protection against health and welfare effects, the 24-

hour PM10 standard provides protection against effects associated with short-term exposure to thoracic 

coarse particles (i.e., PM10-2.5).
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properties of PM2.5 may vary greatly with time, region, meteorology, and source 

category. Thus, PM2.5 may include a complex mixture of different components including 

sulfates, nitrates, organic compounds, elemental carbon and metal compounds. These 

particles can remain in the atmosphere for days to weeks and travel hundreds to 

thousands of kilometers.

b. Health Effects of PM

Scientific studies show ambient PM is associated with a broad range of health 

effects. These health effects are discussed in detail in the December 2009 Integrated 

Science Assessment for Particulate Matter (PM ISA).41 The PM ISA summarizes health 

effects evidence associated with both short- and long-term exposures to PM2.5, PM10-2.5, 

and ultrafine particles. The PM ISA concludes that human exposures to ambient PM2.5

concentrations are associated with a number of adverse health effects and characterizes 

the weight of evidence for these health outcomes.42 The discussion below highlights the 

PM ISA’s conclusions pertaining to health effects associated with both short- and longterm PM exposures. Further discussion of health effects associated with PM2.5 can also 

be found in the rulemaking documents for the most recent review of the PM NAAQS 

completed in 2012.43,44

The EPA concludes that a causal relationship exists between both long- and shortterm exposures to PM2.5 and premature mortality and cardiovascular effects and a likely

causal relationship exists between long- and short-term PM2.5 exposures and respiratory 

effects. Further, there is evidence suggestive of a causal relationship between long-term 

PM2.5 exposures and other health effects, including developmental and reproductive 

effects (e.g., low birth weight, infant mortality) and carcinogenic, mutagenic, and 

genotoxic effects (e.g., lung cancer mortality).45

 

41 U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. 

Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F. 

42 The causal framework draws upon the assessment and integration of evidence from across 

epidemiological, controlled human exposure, and toxicological studies, and the related uncertainties that 

ultimately influence our understanding of the evidence. This framework employs a five-level hierarchy 

that classifies the overall weight of evidence and causality using the following categorizations: causal 

relationship, likely to be causal relationship, suggestive of a causal relationship, inadequate to infer a causal 

relationship, and not likely to be a causal relationship (U.S. EPA. (2009). Integrated Science Assessment 

for Particulate Matter (Final Report). U.S. Environmental Protection Agency, Washington, DC, 

EPA/600/R-08/139F, Table 1–3). 

43 78 FR 3086 (January 15, 2013), pages 3103-3104.

44 77 FR 38890 (June 29, 2012), pages 38906-38911.

45 These causal inferences are based not only on the more expansive epidemiological evidence available in

this review but also reflect consideration of important progress that has been made to advance our 

understanding of a number of potential biologic modes of action or pathways for PM-related cardiovascular 

and respiratory effects (U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final 

Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F, chapter 5).
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As summarized in the Final PM NAAQS rule, and discussed extensively in the 

2009 PM ISA, the scientific evidence available since the completion of the 2006 PM 

NAAQS review significantly strengthens the link between long- and short-term exposure 

to PM2.5 and premature mortality, while providing indications that the magnitude of the 

PM2.5- mortality association with long-term exposures may be larger than previously

estimated. 46,47 The strongest evidence comes from recent studies investigating long-term 

exposure to PM2.5 and cardiovascular-related mortality. The evidence supporting a causal 

relationship between long-term PM2.5 exposure and mortality also includes consideration 

of new studies that demonstrated an improvement in community health following 

reductions in ambient fine particles.

Several studies evaluated in the 2009 PM ISA have examined the association 

between cardiovascular effects and long-term PM2.5 exposures in multi-city studies 

conducted in the U.S. and Europe. While studies were not available in the 2006 PM 

NAAQS review with regard to long-term exposure and cardiovascular-related morbidity, 

studies published since then have provided new evidence linking long-term exposure to 

PM2.5 with an array of cardiovascular effects such as heart attacks, congestive heart 

failure, stroke, and mortality. This evidence is coherent with studies of short-term 

exposure to PM2.5 that have observed associations with a continuum of effects ranging 

from subtle changes in indicators of cardiovascular health to serious clinical events, such 

as increased hospitalizations and emergency department visits due to cardiovascular 

disease and cardiovascular mortality.

48

As detailed in the 2009 PM ISA, extended analyses of studies available in the 

2006 PM NAAQS review as well as epidemiological studies conducted in the U.S. and 

abroad published since then provide stronger evidence of respiratory-related morbidity

effects associated with long-term PM2.5 exposure. The strongest evidence for respiratoryrelated effects is from studies that evaluated decrements in lung function growth (in

children), increased respiratory symptoms, and asthma development. The strongest 

evidence from short-term PM2.5 exposure studies has been observed for increased 

respiratory-related emergency department visits and hospital admissions for chronic 

obstructive pulmonary disease (COPD) and respiratory infections.49

 

46 78 FR 3103-3104 (January 15, 2013).

47 U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. 

Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F, chapter 6 (Section 6.5) and 

chapter 7 (Section 7.6).

48 U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. 

Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F, chapter 2 (section 2.3.1 and 

2.3.2) and chapter 6.

49 U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. 

Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F, chapter 2 (section 2.3.1 and 

2.3.2) and chapter 6.
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The body of scientific evidence detailed in the 2009 PM ISA is still limited with 

respect to associations between long-term PM2.5 exposures and developmental and 

reproductive effects as well as cancer, mutagenic, and genotoxic effects, but is somewhat 

expanded from the 2006 review. The strongest evidence for an association between 

PM2.5 and developmental and reproductive effects comes from epidemiological studies of 

low birth weight and infant mortality, especially due to respiratory causes during the 

post-neonatal period (i.e., 1 month to 12 months of age). 50 With regard to cancer effects, 

‘‘[m]ultiple epidemiologic studies have shown a consistent positive association between 

PM2.5 and lung cancer mortality, but studies have generally not reported associations 

between PM2.5 and lung cancer incidence.’’51

Specific groups within the general population are at increased risk for 

experiencing adverse health effects related to PM exposures.52,53,54, 55 The evidence 

detailed in the 2009 PM ISA expands our understanding of previously identified at-risk 

populations and lifestages (i.e., children, older adults, and individuals with pre-existing 

heart and lung disease) and supports the identification of additional at-risk populations 

(e.g., persons with lower socioeconomic status, genetic differences). Additionally, there 

is emerging, though still limited, evidence for additional potentially at-risk populations 

and lifestages, such as those with diabetes, people who are obese, pregnant women, and 

the developing fetus. 56

For PM10-2.5, the 2009 PM ISA concluded that available evidence was suggestive 

of a causal relationship between short-term exposures to PM10-2.5 and cardiovascular 

effects (e.g., hospital admissions and ED visits, changes in cardiovascular function), 

respiratory effects (e.g, ED visits and hospital admissions, increase in markers of 

pulmonary inflammation), and premature mortality. Data were inadequate to draw 

conclusions regarding the relationships between long-term exposure to PM10-2.5 and 

various health effects. 57,58,59

 

50 U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. 

Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F, chapter 2 (section 2.3.1 and 

2.3.2) and chapter 7.

51 U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. 

Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F. pg 2-13

52 U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. 

Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F. Chapter 8 and Chapter 2.

53 77 FR 38890 (June 29, 2012).

54 78 FR 3104 (January 15, 2013).

55 U.S. EPA. (2011). Policy Assessment for the Review of the PM NAAQS. U.S. Environmental 

Protection Agency, Washington, DC, EPA/452/R-11-003. section 2.2.1.

56 U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. 

Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F. Chapter 8 and Chapter 2 

(Section 2.4.1).

57 U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. 

Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F. Section 2.3.4 and Table 2-6.
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For ultrafine particles, the 2009 PM ISA concluded that the evidence was 

suggestive of a causal relationship between short-term exposures and cardiovascular 

effects, including changes in heart rhythm and vasomotor function (the ability of blood 

vessels to expand and contract). It also concluded that there was evidence suggestive of a 

causal relationship between short-term exposure to ultrafine particles and respiratory

effects, including lung function and pulmonary inflammation, with limited and 

inconsistent evidence for increases in ED visits and hospital admissions. Data were 

inadequate to draw conclusions regarding the relationship between short-term exposure to 

ultrafine particle and additional health effects including premature mortality as well as 

long-term exposure to ultrafine particles and all health outcomes evaluated.60,61

c. Current and Projected Concentrations of PM2.5

There are two primary NAAQS for PM2.5: an annual standard (12.0 micrograms 

per cubic meter (μg/m3)) and a 24-hour standard (35 μg/m3), and two secondary NAAQS 

for PM2.5: an annual standard (15.0 μg/m3) and a 24-hour standard (35 μg/m3). The initial 

PM2.5 standards were set in 1997 and revisions to the standards were finalized in 2006 

and in December 2012. The December 2012 rule revised the level of the primary annual 

PM2.5 standard from 15.0 μg/m3to 12.0 μg/m3.

62

There are many areas of the country that are currently in nonattainment for the 

annual and 24-hour PM2.5 NAAQS. Our modeling without the Tier 3 controls projects 

that in the future we will continue to have many areas that will have ambient PM2.5

concentrations above the level of the NAAQS (see Section III.C.2). States will need to 

meet the 2006 24-hour standards in the 2015-2019 timeframe and the 2012 primary

annual standard in the 2021-2025 timeframe. The emission reductions and improvements 

in ambient PM2.5 concentrations from this action, which will take effect starting in 2017, 

will be helpful to states as they work to attain and maintain the PM2.5 NAAQS.

In 2005 the EPA designated 39 nonattainment areas for the 1997 PM2.5

NAAQS.63 As of December 5, 2013, over 68 million people lived in the 24 areas that are 

still designated as nonattainment for the 1997 annual PM2.5 NAAQS. These PM2.5

nonattainment areas are comprised of 135 full or partial counties. EPA anticipates 

making initial area designation decisions for the 2012 primary annual PM2.5 NAAQS in 

 

58 78 FR 3167-8 (January 15, 2013).

59 77 FR 38947-51 (June 29, 2012).

60 U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. 

Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F. Section 2.3.5 and Table 2-6.

61 78 FR 3121 (January 15, 2013).

62 U.S. EPA (2012). National Ambient Air Quality Standards for Particulate Matter. 

http://www.epa.gov/PM/2012/finalrule.pdf. 78 FR 3164

63 70 FR 19844 (April 14, 2005).
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December 2014, with those designations likely becoming effective in early 2015.64 On 

November 13, 2009 and February 3, 2011, the EPA designated 32 nonattainment areas 

for the 2006 24-hour PM2.5 NAAQS.65 As of December 5, 2013, 28 of these areas remain 

designated as nonattainment, and they are composed of 104 full or partial counties with a 

population of over 65 million. In total, there are currently 39 PM2.5 nonattainment areas 

with a population of over 84 million people.66 

States with PM2.5 nonattainment areas will be required to take action to bring 

those areas into attainment in the future. Designated nonattainment areas not currently 

attaining the 1997 annual PM2.5 NAAQS are required to attain the NAAQS by 2015 and 

will be required to maintain the 1997 annual PM2.5 NAAQS thereafter. The 2006 24-

hour PM2.5 nonattainment areas are required to attain the 2006 24-hour PM2.5 NAAQS in 

the 2015 to 2019 time frame and will be required to maintain the 2006 24-hour PM2.5

NAAQS thereafter. Areas to be designated nonattainment for the 2012 primary annual 

PM2.5 NAAQS will likely be required to attain the 2012 NAAQS in the 2021 to 2025 

time frame. The Tier 3 standards finalized here begin taking effect in 2017. 

The EPA has already adopted many mobile source emission control programs that 

are expected to reduce ambient PM concentrations. As a result of these and other federal, 

state and local programs, the number of areas that fail to meet the PM2.5 NAAQS in the 

future is expected to decrease. However, even with the implementation of all current 

state and federal regulations, there are projected to be counties violating the PM2.5

NAAQS well into the future. Thus additional federal control programs, such as Tier 3, 

can assist areas with attainment dates in 2017 and beyond in attaining the NAAQS as 

expeditiously as practicable and may relieve areas with already stringent local regulations 

from some of the burden associated with adopting additional local controls.

d. Current Concentrations of PM10

In the December 2012 action in which the EPA promulgated the revised primary

annual PM2.5 NAAQS, the EPA also retained the existing primary and secondary 24-hour 

PM10 standards at 150 μg/m3. As of December 5, 2013, over 11 million people live in the 

40 areas that are designated as nonattainment for the PM10 NAAQS. There are 33 full or 

partial counties that make up the PM10 nonattainment areas.

 

64 U.S. EPA (2012). Fact Sheet: Implementing the Standards. 

http://www.epa.gov/airquality/particlepollution/2012/decfsimp.pdf

65 74 FR 58688 (November 13, 2009) and 76 FR 6056 (February 3, 2011).

66

 Data come from Summary Nonattainment Area Population Exposure Report, current as of July 31, 2013

at: http://www.epa.gov/oar/oaqps/greenbk/popexp.html and contained in Docket EPA-HQ-OAR-2011-

0135. 
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3. Oxides of Nitrogen and Sulfur

a. Background

Nitrogen dioxide (NO2) is a member of the NOX family of gases. Most NO2 is 

formed in the air through the oxidation of nitric oxide (NO) emitted when fuel is burned 

at a high temperature. Sulfur dioxide (SO2), a member of the sulfur oxide (SOX) family 

of gases, is formed from burning fuels containing sulfur (e.g., coal or oil derived), 

extracting gasoline from oil, or extracting metals from ore. 

SO2 and NO2 and their gas phase oxidation products can dissolve in water 

droplets and further oxidize to form sulfuric and nitric acid which react with ammonia to 

form sulfates and nitrates, both of which are important components of ambient PM. The 

health effects of ambient PM are discussed in Section II.B.2.b of this preamble. NOX and 

VOC are the two major precursors of ozone. The health effects of ozone are covered in 

Section II.B.2.1.b.

b. Health Effects of NO2

The most recent review of the health effects of oxides of nitrogen completed by

the EPA can be found in the 2008 Integrated Science Assessment for Nitrogen Oxides 

(NOX ISA).67 The EPA concluded that the findings of epidemiologic, controlled human 

exposure, and animal toxicological studies provide evidence that is sufficient to infer a 

likely causal relationship between respiratory effects and short-term NO2 exposure. The 

2008 NOX ISA concluded that the strongest evidence for such a relationship comes from 

epidemiologic studies of respiratory effects including increased respiratory symptoms, 

emergency department visits, and hospital admissions. Based on both short- and longterm exposure studies, the 2008 NOX ISA concluded that individuals with preexisting 

pulmonary conditions (e.g., asthma or COPD), children, and older adults are potentially

at greater risk of NO2-related respiratory effects. Based on findings from controlled 

human exposure studies, the 2008 NOX ISA also drew two broad conclusions regarding 

airway responsiveness following NO2 exposure. First, the NOX ISA concluded that NO2

exposure may enhance the sensitivity to allergen-induced decrements in lung function 

and increase the allergen-induced airway inflammatory response following 30-minute

exposures of asthmatic adults to NO2 concentrations as low as 260 ppb. Second, 

exposure to NO2 has been found to enhance the inherent responsiveness of the airway to 

subsequent nonspecific challenges in controlled human exposure studies of healthy and 

asthmatic adults. Small but statistically significant increases in nonspecific airway

hyperresponsiveness were reported for asthmatic adults following 30-minute exposures to 

200-300 ppb NO2 and following 1-hour exposures of asthmatics to 100 ppb NO2. 

Enhanced airway responsiveness could have important clinical implications for 

 

67 U.S. EPA (2008). Integrated Science Assessment for Oxides of Nitrogen – Health Criteria (Final 

Report). EPA/600/R-08/071. Washington, DC: U.S.EPA. 
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asthmatics since transient increases in airway responsiveness following NO2 exposure 

have the potential to increase symptoms and worsen asthma control. Together, the 

epidemiologic and experimental data sets form a plausible, consistent, and coherent 

description of a relationship between NO2 exposures and an array of adverse health 

effects that range from the onset of respiratory symptoms to hospital admission. 

In evaluating a broader range of health effects, the 2008 NOX ISA concluded 

evidence was “suggestive but not sufficient to infer a causal relationship” between shortterm NO2 exposure and premature mortality and between long-term NO2 exposure and 

respiratory effects. The latter was based largely on associations observed between longterm NO2 exposure and decreases in lung function growth in children. Furthermore, the 

2008 NOX ISA concluded that evidence was “inadequate to infer the presence or absence 

of a causal relationship” between short-term NO2 exposure and cardiovascular effects as 

well as between long-term NO2 exposure and cardiovascular effects, reproductive and 

developmental effects, premature mortality, and cancer.68 The conclusions for these 

health effect categories were informed by uncertainties in the evidence base such as the 

independent effects of NO2 exposure within the broader mixture of traffic-related 

pollutants, limited evidence from experimental studies, and/or an overall limited literature 

base.

c. Health Effects of SO2

Information on the health effects of SO2 can be found in the 2008 Integrated 

Science Assessment for Sulfur Oxides (SO2 ISA).69 Short-term peaks of SO2 have long 

been known to cause adverse respiratory health effects, particularly among individuals 

with asthma. In addition to those with asthma (both children and adults), potentially

sensitive groups include all children and the elderly. During periods of elevated 

ventilation, asthmatics may experience symptomatic bronchoconstriction within minutes 

of exposure. Following an extensive evaluation of health evidence from epidemiologic 

and laboratory studies, the EPA concluded that there is a causal relationship between 

respiratory health effects and short-term exposure to SO2. Separately, based on an 

evaluation of the epidemiologic evidence of associations between short-term exposure to 

SO2 and mortality, the EPA concluded that the overall evidence is suggestive of a causal 

relationship between short-term exposure to SO2 and mortality.

d. Current Concentrations of NO2

The EPA most recently completed a review of the primary NAAQS for NO2 in 

January 2010. There are two primary NAAQS for NO2: an annual standard (53 ppb) and 

 

68 U.S. EPA (2008). Integrated Science Assessment for Oxides of Nitrogen – Health Criteria (Final 

Report). EPA/600/R-08/071. Washington, DC: U.S.EPA.

69 U.S. EPA. (2008). Integrated Science Assessment (ISA) for Sulfur Oxides – Health Criteria (Final 

Report). EPA/600/R-08/047F. Washington, DC: U.S. Environmental Protection Agency.
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a 1-hour standard (100 ppb). The EPA promulgated area designations in the Federal 

Register on February 17, 2012. In this initial round of designations, all areas of the 

country were designated as “unclassifiable/attainment” for the 2010 NO2 NAAQS based 

on data from the existing air quality monitoring network. The EPA and state agencies are 

working to establish an expanded network of NO2 monitors, expected to be deployed in 

the 2014-2017 time frame. Once three years of air quality data have been collected from 

the expanded network, the EPA will be able to evaluate NO2 air quality in additional 

locations.70,71

e. Current Concentrations of SO2

The EPA most recently completed a review of the primary SO2 NAAQS in June 

2010. The current primary NAAQS for SO2 is a 1-hour standard of 75 ppb. The EPA 

finalized the initial area designations for 29 nonattainment areas in 16 states in a notice

published in the Federal Register on August 5, 2013. In this first round of designations, 

EPA only designated nonattainment areas that were violating the standard based on 

existing air quality monitoring data provided by the states. The Agency did not have 

sufficient information to designate any area as “attainment” or make final decisions about 

areas for which additional modeling or monitoring is needed (78 FR 47191, August 5, 

2013). EPA anticipates designating areas for the revised SO2 standard in multiple 

rounds.

4. Carbon Monoxide

Carbon monoxide (CO) is a colorless, odorless gas emitted from combustion 

processes. Nationally and, particularly in urban areas, the majority of CO emissions to 

ambient air come from mobile sources.

a. Health Effects of Carbon Monoxide

Information on the health effects of CO can be found in the January 2010 

Integrated Science Assessment for Carbon Monoxide (CO ISA).72 The CO ISA 

concludes that ambient concentrations of CO are associated with a number of adverse 

 

70 U.S. EPA. (2012). Fact Sheet – Air Quality Designations for the 2010 Primary Nitrogen Dioxide (NO2) 

National Ambient Air Quality Standards. 

http://www.epa.gov/airquality/nitrogenoxides/designations/pdfs/20120120FS.pdf

71 U.S. Environmental Protection Agency (2013). Revision to Ambient Nitrogen Dioxide Monitoring 

Requirements. March 7, 2013. http://www.epa.gov/airquality/nitrogenoxides/pdfs/20130307fr.pdf

72 U.S. EPA, (2010). Integrated Science Assessment for Carbon Monoxide (Final Report). U.S. 

Environmental Protection Agency, Washington, DC, EPA/600/R-09/019F, 2010. Available at

http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=218686. 
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health effects.73 This section provides a summary of the health effects associated with 

exposure to ambient concentrations of CO.74 

Controlled human exposure studies of subjects with coronary artery disease show 

a decrease in the time to onset of exercise-induced angina (chest pain) and 

electrocardiogram changes following CO exposure. In addition, epidemiologic studies 

show associations between short-term CO exposure and cardiovascular morbidity, 

particularly increased emergency room visits and hospital admissions for coronary heart 

disease (including ischemic heart disease, myocardial infarction, and angina). Some 

epidemiologic evidence is also available for increased hospital admissions and 

emergency room visits for congestive heart failure and cardiovascular disease as a whole. 

The CO ISA concludes that a causal relationship is likely to exist between short-term 

exposures to CO and cardiovascular morbidity. It also concludes that available data are 

inadequate to conclude that a causal relationship exists between long-term exposures to 

CO and cardiovascular morbidity. 

Animal studies show various neurological effects with in-utero CO exposure. 

Controlled human exposure studies report central nervous system and behavioral effects 

following low-level CO exposures, although the findings have not been consistent across 

all studies. The CO ISA concludes the evidence is suggestive of a causal relationship 

with both short- and long-term exposure to CO and central nervous system effects.

A number of studies cited in the CO ISA have evaluated the role of CO exposure 

in birth outcomes such as preterm birth or cardiac birth defects. The epidemiologic 

studies provide limited evidence of a CO-induced effect on preterm births and birth 

defects, with weak evidence for a decrease in birth weight. Animal toxicological studies 

have found perinatal CO exposure to affect birth weight, as well as other developmental 

outcomes. The CO ISA concludes the evidence is suggestive of a causal relationship 

between long-term exposures to CO and developmental effects and birth outcomes.

Epidemiologic studies provide evidence of associations between ambient CO 

concentrations and respiratory morbidity such as changes in pulmonary function, 

respiratory symptoms, and hospital admissions. A limited number of epidemiologic 

studies considered copollutants such as ozone, SO2, and PM in two-pollutant models and 

found that CO risk estimates were generally robust, although this limited evidence makes 

it difficult to disentangle effects attributed to CO itself from those of the larger complex 

 

73 The ISA evaluates the health evidence associated with different health effects, assigning one of five 

“weight of evidence” determinations: causal relationship, likely to be a causal relationship, suggestive of a 

causal relationship, inadequate to infer a causal relationship, and not likely to be a causal relationship. For 

definitions of these levels of evidence, please refer to Section 1.6 of the ISA. 

74 Personal exposure includes contributions from many sources, and in many different environments. Total 

personal exposure to CO includes both ambient and nonambient components; and both components may 

contribute to adverse health effects.
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air pollution mixture. Controlled human exposure studies have not extensively evaluated 

the effect of CO on respiratory morbidity. Animal studies at levels of 50-100 ppm CO 

show preliminary evidence of altered pulmonary vascular remodeling and oxidative 

injury. The CO ISA concludes that the evidence is suggestive of a causal relationship 

between short-term CO exposure and respiratory morbidity, and inadequate to conclude 

that a causal relationship exists between long-term exposure and respiratory morbidity. 

Finally, the CO ISA concludes that the epidemiologic evidence is suggestive of a 

causal relationship between short-term concentrations of CO and mortality. 

Epidemiologic studies provide evidence of an association between short-term exposure to 

CO and mortality, but limited evidence is available to evaluate cause-specific mortality

outcomes associated with CO exposure. In addition, the attenuation of CO risk estimates 

which was often observed in copollutant models contributes to the uncertainty as to 

whether CO is acting alone or as an indicator for other combustion-related pollutants. The 

CO ISA also concludes that there is not likely to be a causal relationship between 

relevant long-term exposures to CO and mortality.

b. Current Concentrations of CO

There are two NAAQS for CO: an 8-hour standard (9 ppm) and a 1-hour standard 

(35 ppm). The primary NAAQS for CO were retained in August 2011. There are 

currently no CO nonattainment areas; as of September 27, 2010, all CO nonattainment 

areas were redesignated to maintenance areas. The designations were based on the 

existing community-wide monitoring network. EPA is making changes to the ambient 

air monitoring requirements for CO. The new requirements are expected to result in 

approximately 52 CO monitors operating near roads within 52 urban areas by January

2015 (76 FR 54294, August 31, 2011). 

5. Mobile Source Air Toxics

Light-duty vehicle emissions contribute to ambient levels of air toxics known or 

suspected as human or animal carcinogens, or that have noncancer health effects. The 

population experiences an elevated risk of cancer and other noncancer health effects from 

exposure to the class of pollutants known collectively as “air toxics.”75 These 

compounds include, but are not limited to, benzene, 1,3-butadiene, formaldehyde, 

acetaldehyde, acrolein, polycyclic organic matter, and naphthalene. These compounds 

were identified as national or regional risk drivers or contributors in the 2005 Nationalscale Air Toxics Assessment and have significant inventory contributions from mobile 

sources.76 

 

75 U.S. EPA. (2011) Summary of Results for the 2005 National-Scale Assessment. 

www.epa.gov/ttn/atw/nata2005/05pdf/sum_results.pdf. 

76 U.S. EPA (2011) 2005 National-Scale Air Toxics Assessment. http://www.epa.gov/ttn/atw/nata2005. 
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a. Health Effects of Air Toxics

i. Benzene

The EPA’s Integrated Risk Information System (IRIS) database lists benzene as a 

known human carcinogen (causing leukemia) by all routes of exposure, and concludes 

that exposure is associated with additional health effects, including genetic changes in 

both humans and animals and increased proliferation of bone marrow cells in mice.77,78,79 

EPA states in its IRIS database that data indicate a causal relationship between benzene 

exposure and acute lymphocytic leukemia and suggest a relationship between benzene 

exposure and chronic non-lymphocytic leukemia and chronic lymphocytic leukemia. 

EPA’s IRIS documentation for benzene also lists a range of 2.2 x 10-6to 7.8 x 10-6as the 

unit risk estimate (URE) for benzene.80,81 The International Agency for Research on 

Carcinogens (IARC) has determined that benzene is a human carcinogen and the U.S. 

Department of Health and Human Services (DHHS) has characterized benzene as a 

known human carcinogen.82,83 

A number of adverse noncancer health effects including blood disorders, such as 

preleukemia and aplastic anemia, have also been associated with long-term exposure to 

benzene.84,85 The most sensitive noncancer effect observed in humans, based on current 

data, is the depression of the absolute lymphocyte count in blood.86,87 EPA’s inhalation 

 

77 U.S. EPA. (2000). Integrated Risk Information System File for Benzene. This material is available 

electronically at: http://www.epa.gov/iris/subst/0276.htm. 

78 International Agency for Research on Cancer, IARC monographs on the evaluation of carcinogenic risk 

of chemicals to humans, Volume 29, Some industrial chemicals and dyestuffs, International Agency for 

Research on Cancer, World Health Organization, Lyon, France 1982. 

79 Irons, R.D.; Stillman, W.S.; Colagiovanni, D.B.; Henry, V.A. (1992). Synergistic action of the benzene 

metabolite hydroquinone on myelopoietic stimulating activity of granulocyte/macrophage colonystimulating factor in vitro, Proc. Natl. Acad. Sci. 89:3691-3695. 

80 A unit risk estimate is defined as the increase in the lifetime risk of an individual who is exposed for a 

lifetime to 1 μg/m3 benzene in air.

81 U.S. EPA. (2000). Integrated Risk Information System File for Benzene. This material is available 

electronically at: http://www.epa.gov/iris/subst/0276.htm. 

82 International Agency for Research on Cancer (IARC). (1987). Monographs on the evaluation of 

carcinogenic risk of chemicals to humans, Volume 29, Supplement 7, Some industrial chemicals and 

dyestuffs, World Health Organization, Lyon, France.

83 U.S. Department of Health and Human Services National Toxicology Program. (2011). 12th Report on 

Carcinogens. Available at: http://ntp.niehs.nih.gov/?objectid=03C9AF75-E1BF-FF40-

DBA9EC0928DF8B15. 

84 Aksoy, M. (1989). Hematotoxicity and carcinogenicity of benzene. Environ. Health Perspect. 82: 193-

197. 

85 Goldstein, B.D. (1988). Benzene toxicity. Occupational medicine. State of the Art Reviews. 3: 541-

554.

86 Rothman, N., G.L. Li, M. Dosemeci, W.E. Bechtold, G.E. Marti, Y.Z. Wang, M. Linet, L.Q. Xi, W. Lu, 

M.T. Smith, N. Titenko-Holland, L.P. Zhang, W. Blot, S.N. Yin, and R.B. Hayes. (1996). Hematotoxicity 

among Chinese workers heavily exposed to benzene. Am. J. Ind. Med. 29: 236-246. 
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reference concentration (RfC) for benzene is 30 μg/m3. The RfC is based on suppressed 

absolute lymphocyte counts seen in humans under occupational exposure conditions. In 

addition, recent work, including studies sponsored by the Health Effects Institute, 

provides evidence that biochemical responses are occurring at lower levels of benzene 

exposure than previously known.88,89,90,91 EPA’s IRIS program has not yet evaluated 

these new data. EPA does not currently have an acute reference concentration for 

benzene. The Agency for Toxic Substances and Disease Registry (ATSDR) Minimal 

Risk Level (MRL) for acute exposure to benzene is 29 μg/m3for 1-14 days exposure.92,93

ii. Formaldehyde 

In 1991, EPA concluded that formaldehyde is a carcinogen based on nasal tumors 

in animal bioassays.94 An Inhalation Unit Risk for cancer and a Reference Dose for oral 

noncancer effects were developed by the Agency and posted on the IRIS database. Since 

that time, the National Toxicology Program (NTP) and International Agency for 

Research on Cancer (IARC) have concluded that formaldehyde is a known human 

carcinogen.95,96,97

 

87 U.S. EPA. (2002). Toxicological Review of Benzene (Noncancer Effects). Environmental Protection 

Agency, Integrated Risk Information System (IRIS), Research and Development, National Center for 

Environmental Assessment, Washington DC. This material is available electronically at 

http://www.epa.gov/iris/subst/0276.htm. 

88 Qu, O.; Shore, R.; Li, G.; Jin, X.; Chen, C.L.; Cohen, B.; Melikian, A.; Eastmond, D.; Rappaport, S.; Li, 

H.; Rupa, D.; Suramaya, R.; Songnian, W.; Huifant, Y.; Meng, M.; Winnik, M.; Kwok, E.; Li, Y.; Mu, 

R.; Xu, B.; Zhang, X.; Li, K. (2003). HEI Report 115, Validation & Evaluation of Biomarkers in Workers 

Exposed to Benzene in China.

89 Qu, Q., R. Shore, G. Li, X. Jin, L.C. Chen, B. Cohen, et al. (2002). Hematological changes among 

Chinese workers with a broad range of benzene exposures. Am. J. Industr. Med. 42: 275-285. 

90 Lan, Qing, Zhang, L., Li, G., Vermeulen, R., et al. (2004). Hematotoxically in Workers Exposed to Low

Levels of Benzene. Science 306: 1774-1776.

91 Turtletaub, K.W. and Mani, C. (2003). Benzene metabolism in rodents at doses relevant to human 

exposure from Urban Air. Research Reports Health Effect Inst. Report No.113. 

92 U.S. Agency for Toxic Substances and Disease Registry (ATSDR). (2007). Toxicological profile for 

benzene. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service. 

http://www.atsdr.cdc.gov/ToxProfiles/tp3.pdf.

93 A minimal risk level (MRL) is defined as an estimate of the daily human exposure to a hazardous 

substance that is likely to be without appreciable risk of adverse noncancer health effects over a specified 

duration of exposure.

94 EPA. Integrated Risk Information System. Formaldehyde (CASRN 50-00-0) 

http://www.epa.gov/iris/subst/0419/htm

95 National Toxicology Program, U.S. Department of Health and Human Services (HHS), 12th Report on 

Carcinogens, June 10, 2011

96 IARC Monographs on the Evaluation of Carcinogenic Risks to Humans Volume 88 (2006): 

Formaldehyde, 2-Butoxyethanol and 1-tert-Butoxypropan-2-ol

97 IARC Mongraphs on the Evaluation of Carcinogenic Risks to Humans Volume 100F (2012): 

Formaldehyde
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The conclusions by IARC and NTP reflect the results of epidemiologic research 

published since 1991 in combination with previous animal, human and mechanistic 

evidence. Research conducted by the National Cancer Institute reported an increased risk 

of nasopharyngeal cancer and specific lymphohematopoietic malignancies among 

workers exposed to formaldehyde.98,99,100 A National Institute of Occupational Safety 

and Health study of garment workers also reported increased risk of death due to 

leukemia among workers exposed to formaldehyde.101 Extended follow-up of a cohort of 

British chemical workers did not report evidence of an increase in nasopharyngeal or 

lymphohematopoietic cancers, but a continuing statistically significant excess in lung 

cancers was reported.102 Finally, a study of embalmers reported formaldehyde exposures 

to be associated with an increased risk of myeloid leukemia but not brain cancer.103

Health effects of formaldehyde in addition to cancer were reviewed by the 

Agency for Toxics Substances and Disease Registry in 1999104 and supplemented in 

2010,105 and by the World Health Organization.106 These organizations reviewed the 

literature concerning effects on the eyes and respiratory system, the primary point of 

contact for inhaled formaldehyde, including sensory irritation of eyes and respiratory

tract, pulmonary function, nasal histopathology, and immune system effects. In addition, 

research on reproductive and developmental effects and neurological effects were 

discussed.

EPA released a draft Toxicological Review of Formaldehyde – Inhalation 

Assessment through the IRIS program for peer review by the National Research Council 

 

98 Hauptmann, M..; Lubin, J. H.; Stewart, P. A.; Hayes, R. B.; Blair, A. 2003. Mortality from 

lymphohematopoetic malignancies among workers in formaldehyde industries. Journal of the National 

Cancer Institute 95: 1615-1623. 

99 Hauptmann, M..; Lubin, J. H.; Stewart, P. A.; Hayes, R. B.; Blair, A. 2004. Mortality from solid cancers 

among workers in formaldehyde industries. American Journal of Epidemiology 159: 1117-1130. 

100 Beane Freeman, L. E.; Blair, A.; Lubin, J. H.; Stewart, P. A.; Hayes, R. B.; Hoover, R. N.; Hauptmann, 

M. 2009. Mortality from lymphohematopoietic malignancies among workers in formaldehyde industries: 

The National Cancer Institute cohort. J. National Cancer Inst. 101: 751-761. 

101 Pinkerton, L. E. 2004. Mortality among a cohort of garment workers exposed to formaldehyde: an 

update. Occup. Environ. Med. 61: 193-200.

102 Coggon, D, EC Harris, J Poole, KT Palmer. 2003. Extended follow-up of a cohort of British chemical 

workers exposed to formaldehyde. J National Cancer Inst. 95:1608-1615.

103 Hauptmann, M,; Stewart P. A.; Lubin J. H.; Beane Freeman, L. E.; Hornung, R. W.; Herrick, R. F.; 

Hoover, R. N.; Fraumeni, J. F.; Hayes, R. B. 2009. Mortality from lymphohematopoietic malignancies and 

brain cancer among embalmers exposed to formaldehyde. Journal of the National Cancer Institute 

101:1696-1708.

104 ATSDR. 1999. Toxicological Profile for Formaldehyde, U.S. Department of Health and Human Services 

(HHS), July 1999.

105 ATSDR. 2010. Addendum to theToxicological Profile for Formaldehyde. U.S. Department of Health 

and Human Services (HHS), October 2010.

106 IPCS. 2002. Concise International Chemical Assessment Document 40. Formaldehyde. World Health

Organization.
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(NRC) and public comment in June 2010.107 The draft assessment reviewed more recent 

research from animal and human studies on cancer and other health effects. The NRC 

released their review report in April 2011.108 The EPA is currently revising the draft 

assessment in response to this review.

iii.Acetaldehyde 

Acetaldehyde is classified in EPA’s IRIS database as a probable human 

carcinogen, based on nasal tumors in rats, and is considered toxic by the inhalation, oral, 

and intravenous routes.109 The URE in IRIS for acetaldehyde is 2.2 × 10-6per μg/m3.

110

 

Acetaldehyde is reasonably anticipated to be a human carcinogen by the U.S. DHHS in 

the 12th Report on Carcinogens and is classified as possibly carcinogenic to humans 

(Group 2B) by the IARC.111,112 EPA is currently conducting a reassessment of cancer 

risk from inhalation exposure to acetaldehyde.

The primary noncancer effects of exposure to acetaldehyde vapors include 

irritation of the eyes, skin, and respiratory tract.113 In short-term (4 week) rat studies, 

degeneration of olfactory epithelium was observed at various concentration levels of 

acetaldehyde exposure.114,115 Data from these studies were used by EPA to develop an 

inhalation reference concentration of 9 μg/m3. Some asthmatics have been shown to be a 

sensitive subpopulation to decrements in functional expiratory volume (FEV1 test) and 

 

107 EPA (U.S. Environmental Protection Agency). 2010. Toxicological Review of Formaldehyde (CAS No. 

50-00-0) – Inhalation Assessment: In Support of Summary Information on the Integrated Risk Information 

System (IRIS). External Review Draft. EPA/635/R-10/002A. U.S. Environmental Protection Agency, 

Washington DC [online]. Available: http://cfpub.epa.gov/ncea/irs_drats/recordisplay.cfm?deid=223614

108 NRC (National Research Council). 2011. Review of the Environmental Protection Agency’s Draft IRIS

Assessment of Formaldehyde. Washington DC: National Academies Press. 

http://books.nap.edu/openbook.php?record_id=13142

109 U.S. EPA (1991). Integrated Risk Information System File of Acetaldehyde. Research and 

Development, National Center for Environmental Assessment, Washington, DC. This material is available 

electronically at http://www.epa.gov/iris/subst/0290.htm. 

110 U.S. EPA (1991). Integrated Risk Information System File of Acetaldehyde. This material is available 

electronically at http://www.epa.gov/iris/subst/0290.htm. 

111 NTP. (2011). Report on Carcinogens, Twelfth Edition. Research Triangle Park, NC: U.S. Department of 

Health and Human Services, Public Health Service, National Toxicology Program. 499 pp.

112 International Agency for Research on Cancer (IARC). (1999). Re-evaluation of some organic chemicals, 

hydrazine, and hydrogen peroxide. IARC Monographs on the Evaluation of Carcinogenic Risk of 

Chemical to Humans, Vol 71. Lyon, France.

113 U.S. EPA (1991). Integrated Risk Information System File of Acetaldehyde. This material is available 

electronically at http://www.epa.gov/iris/subst/0290.htm. 

114 U.S. EPA. (2003). Integrated Risk Information System File of Acrolein. Research and Development, 

National Center for Environmental Assessment, Washington, DC. This material is available electronically 

at http://www.epa.gov/iris/subst/0364.htm. 

115 Appleman, L.M., R.A. Woutersen, and V.J. Feron. (1982). Inhalation toxicity of acetaldehyde in rats. I. 

Acute and subacute studies. Toxicology. 23: 293-297. 
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bronchoconstriction upon acetaldehyde inhalation.116 The agency is currently conducting 

a reassessment of the health hazards from inhalation exposure to acetaldehyde. 

iv. Acrolein

EPA most recently evaluated the toxicological and health effects literature related 

to acrolein in 2003 and concluded that the human carcinogenic potential of acrolein could 

not be determined because the available data were inadequate. No information was 

available on the carcinogenic effects of acrolein in humans and the animal data provided 

inadequate evidence of carcinogenicity.

117

 The IARC determined in 1995 that acrolein 

was not classifiable as to its carcinogenicity in humans.118 

Lesions to the lungs and upper respiratory tract of rats, rabbits, and hamsters have 

been observed after subchronic exposure to acrolein.119 The Agency has developed an 

RfC for acrolein of 0.02 μg/m3 and an RfD of 0.5 μg/kg-day.

120

 EPA is considering 

updating the acrolein assessment with data that have become available since the 2003 

assessment was completed.

Acrolein is extremely acrid and irritating to humans when inhaled, with acute 

exposure resulting in upper respiratory tract irritation, mucus hypersecretion and 

congestion. The intense irritancy of this carbonyl has been demonstrated during 

controlled tests in human subjects, who suffer intolerable eye and nasal mucosal sensory

reactions within minutes of exposure.121 These data and additional studies regarding 

acute effects of human exposure to acrolein are summarized in EPA’s 2003 IRIS Human 

Health Assessment for acrolein.122 Studies in humans indicate that levels as low as 0.09 

ppm (0.21 mg/m3) for five minutes may elicit subjective complaints of eye irritation with 

 

116 Myou, S.; Fujimura, M.; Nishi K.; Ohka, T.; and Matsuda, T. (1993) Aerosolized acetaldehyde induces 

histamine-mediated bronchoconstriction in asthmatics. Am. Rev. Respir.Dis.148(4 Pt 1): 940-943. 

117 U.S. EPA. (2003). Integrated Risk Information System File of Acrolein. Research and Development, 

National Center for Environmental Assessment, Washington, DC. This material is available at 

http://www.epa.gov/iris/subst/0364.htm. 

118 International Agency for Research on Cancer (IARC). (1995). Monographs on the evaluation of 

carcinogenic risk of chemicals to humans, Volume 63. Dry cleaning, some chlorinated solvents and other 

industrial chemicals, World Health Organization, Lyon, France. 

119 U.S. EPA. (2003). Integrated Risk Information System File of Acrolein. Office of Research and 

Development, National Center for Environmental Assessment, Washington, DC. This material is available 

at http://www.epa.gov/iris/subst/0364.htm. 

120 U.S. EPA. (2003). Integrated Risk Information System File of Acrolein. Office of Research and 

Development, National Center for Environmental Assessment, Washington, DC. This material is available 

at http://www.epa.gov/iris/subst/0364.htm. 

121 U.S. EPA. (2003) Toxicological review of acrolein in support of summary information on Integrated 

Risk Information System (IRIS) National Center for Environmental Assessment, Washington, DC. 

EPA/635/R-03/003. p. 10. Available online at: http://www.epa.gov/ncea/iris/toxreviews/0364tr.pdf. 

122 U.S. EPA. (2003) Toxicological review of acrolein in support of summary information on Integrated 

Risk Information System (IRIS) National Center for Environmental Assessment, Washington, DC. 

EPA/635/R-03/003. Available online at: http://www.epa.gov/ncea/iris/toxreviews/0364tr.pdf. 
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increasing concentrations leading to more extensive eye, nose and respiratory symptoms. 

Acute exposures in animal studies report bronchial hyper-responsiveness. Based on 

animal data (more pronounced respiratory irritancy in mice with allergic airway disease 

in comparison to non-diseased mice123) and demonstration of similar effects in humans 

(e.g., reduction in respiratory rate), individuals with compromised respiratory function 

(e.g., emphysema, asthma) are expected to be at increased risk of developing adverse 

responses to strong respiratory irritants such as acrolein. EPA does not currently have an 

acute reference concentration for acrolein. The available health effect reference values 

for acrolein have been summarized by EPA and include an ATSDR MRL for acute 

exposure to acrolein of 7 μg/m3for 1-14 days exposure; and Reference Exposure Level 

(REL) values from the California Office of Environmental Health Hazard Assessment 

(OEHHA) for one-hour and 8-hour exposures of 2.5 μg/m3and 0.7 μg/m3, 

respectively.

124

v. 1,3-Butadiene

EPA has characterized 1,3-butadiene as carcinogenic to humans by

inhalation.125,126 The IARC has determined that 1,3-butadiene is a human carcinogen and 

the U.S. DHHS has characterized 1,3-butadiene as a known human carcinogen.127,128,129 

There are numerous studies consistently demonstrating that 1,3-butadiene is metabolized 

into genotoxic metabolites by experimental animals and humans. The specific 

mechanisms of 1,3-butadiene-induced carcinogenesis are unknown; however, the 

scientific evidence strongly suggests that the carcinogenic effects are mediated by

genotoxic metabolites. Animal data suggest that females may be more sensitive than 

males for cancer effects associated with 1,3-butadiene exposure; there are insufficient 

data in humans from which to draw conclusions about sensitive subpopulations. The 

 

123 Morris JB, Symanowicz PT, Olsen JE, et al. (2003). Immediate sensory nerve-mediated respiratory 

responses to irritants in healthy and allergic airway-diseased mice. J Appl Physiol 94(4):1563-1571. 

124 U.S. EPA. (2009). Graphical Arrays of Chemical-Specific Health Effect Reference Values for Inhalation 

Exposures (Final Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-09/061, 

2009. http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=211003 

125 U.S. EPA. (2002). Health Assessment of 1,3-Butadiene. Office of Research and Development, National 

Center for Environmental Assessment, Washington Office, Washington, DC. Report No. EPA600-P-98-

001F. This document is available electronically at http://www.epa.gov/iris/supdocs/buta-sup.pdf. 

126 U.S. EPA. (2002). “Full IRIS Summary for 1,3-butadiene (CASRN 106-99-0)” Environmental 

Protection Agency, Integrated Risk Information System (IRIS), Research and Development, National 

Center for Environmental Assessment, Washington, DC http://www.epa.gov/iris/subst/0139.htm. 

127 International Agency for Research on Cancer (IARC). (1999). Monographs on the evaluation of 

carcinogenic risk of chemicals to humans, Volume 71, Re-evaluation of some organic chemicals, hydrazine 

and hydrogen peroxide and Volume 97 (in preparation), World Health Organization, Lyon, France. 

128 International Agency for Research on Cancer (IARC). (2008). Monographs on the evaluation of 

carcinogenic risk of chemicals to humans, 1,3-Butadiene, Ethylene Oxide and Vinyl Halides (Vinyl 

Fluoride, Vinyl Chloride and Vinyl Bromide) Volume 97, World Health Organization, Lyon, France. 

129 NTP. (2011). Report on Carcinogens, Twelfth Edition. Research Triangle Park, NC: U.S. Department of 

Health and Human Services, Public Health Service, National Toxicology Program. 499 pp.
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URE for 1,3-butadiene is 3 × 10-5per μg/m3.

130 1,3-butadiene also causes a variety of 

reproductive and developmental effects in mice; no human data on these effects are 

available. The most sensitive effect was ovarian atrophy observed in a lifetime bioassay

of female mice.131 Based on this critical effect and the benchmark concentration 

methodology, an RfC for chronic health effects was calculated at 0.9 ppb (approximately

2 μg/m3).

vi. Ethanol

EPA is planning to develop an assessment of the health effects of exposure to 

ethanol, a compound which is not currently listed on EPA’s IRIS database. Extensive 

health effects data are available for ingestion of ethanol, while data on inhalation 

exposure effects are sparse. In developing the assessment, EPA is evaluating 

pharmacokinetic models as a means of extrapolating across species (animal to human) 

and across exposure routes (oral to inhalation) to better characterize the health hazards 

and dose-response relationships for low levels of ethanol exposure in the environment.

vii. Polycyclic Organic Matter

The term polycyclic organic matter (POM) defines a broad class of compounds 

that includes the polycyclic aromatic hydrocarbon compounds (PAHs). One of these 

compounds, naphthalene, is discussed separately below. POM compounds are formed 

primarily from combustion and are present in the atmosphere in gas and particulate form. 

Cancer is the major concern from exposure to POM. Epidemiologic studies have 

reported an increase in lung cancer in humans exposed to diesel exhaust, coke oven 

emissions, roofing tar emissions, and cigarette smoke; all of these mixtures contain POM 

compounds.132,133 Animal studies have reported respiratory tract tumors from inhalation 

exposure to benzo[a]pyrene and alimentary tract and liver tumors from oral exposure to 

benzo[a]pyrene.134 In 1997 EPA classified seven PAHs (benzo[a]pyrene, 

benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, 

 

130 U.S. EPA. (2002). “Full IRIS Summary for 1,3-butadiene (CASRN 106-99-0)” Environmental 

Protection Agency, Integrated Risk Information System (IRIS), Research and Development, National 

Center for Environmental Assessment, Washington, DC http://www.epa.gov/iris/subst/0139.htm. 

131 Bevan, C.; Stadler, J.C.; Elliot, G.S.; et al. (1996). Subchronic toxicity of 4-vinylcyclohexene in rats and 

mice by inhalation. Fundam. Appl. Toxicol. 32:1-10.

132 Agency for Toxic Substances and Disease Registry (ATSDR). (1995). Toxicological profile for 

Polycyclic Aromatic Hydrocarbons (PAHs). Atlanta, GA: U.S. Department of Health and Human Services, 

Public Health Service. Available electronically at 

http://www.atsdr.cdc.gov/ToxProfiles/TP.asp?id=122&tid=25. 

133 U.S. EPA (2002). Health Assessment Document for Diesel Engine Exhaust. EPA/600/8-90/057F Office 

of Research and Development, Washington DC. 

http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=29060. 

134 International Agency for Research on Cancer (IARC). (2012). Monographs on the Evaluation of the 

Carcinogenic Risk of Chemicals for Humans, Chemical Agents and Related Occupations. Vol. 100F. 

Lyon, France.
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dibenz[a,h]anthracene, and indeno[1,2,3-cd]pyrene) as Group B2, probable human 

carcinogens.135 Since that time, studies have found that maternal exposures to PAHs in a 

population of pregnant women were associated with several adverse birth outcomes, 

including low birth weight and reduced length at birth, as well as impaired cognitive 

development in preschool children (3 years of age).136,137 These and similar studies are 

being evaluated as a part of the ongoing IRIS assessment of health effects associated with 

exposure to benzo[a]pyrene.

viii. Naphthalene

Naphthalene is found in small quantities in gasoline and diesel fuels. 

Naphthalene emissions have been measured in larger quantities in both gasoline and 

diesel exhaust compared with evaporative emissions from mobile sources, indicating it is 

primarily a product of combustion. Acute (short-term) exposure of humans to 

naphthalene by inhalation, ingestion, or dermal contact is associated with hemolytic 

anemia and damage to the liver and the nervous system.138 Chronic (long term) exposure 

of workers and rodents to naphthalene has been reported to cause cataracts and retinal 

damage.139 EPA released an external review draft of a reassessment of the inhalation 

carcinogenicity of naphthalene based on a number of recent animal carcinogenicity

studies.140 The draft reassessment completed external peer review.141 Based on external 

peer review comments received, a revised draft assessment that considers all routes of 

exposure, as well as cancer and noncancer effects, is under development. The external 

 

135 U.S. EPA (1997). Integrated Risk Information System File of indeno(1,2,3-cd)pyrene. Research and 

Development, National Center for Environmental Assessment, Washington, DC. This material is available 

electronically at http://www.epa.gov/ncea/iris/subst/0457.htm. 

136 Perera, F.P.; Rauh, V.; Tsai, W-Y.; et al. (2002). Effect of transplacental exposure to environmental 

pollutants on birth outcomes in a multiethnic population. Environ Health Perspect. 111: 201-205. 

137 Perera, F.P.; Rauh, V.; Whyatt, R.M.; Tsai, W.Y.; Tang, D.; Diaz, D.; Hoepner, L.; Barr, D.; Tu, Y.H.; 

Camann, D.; Kinney, P. (2006). Effect of prenatal exposure to airborne polycyclic aromatic hydrocarbons 

on neurodevelopment in the first 3 years of life among inner-city children. Environ Health Perspect 114: 

1287-1292. 

138 U. S. EPA. 1998. Toxicological Review of Naphthalene (Reassessment of the Inhalation Cancer Risk), 

Environmental Protection Agency, Integrated Risk Information System, Research and Development, 

National Center for Environmental Assessment, Washington, DC. This material is available electronically 

at http://www.epa.gov/iris/subst/0436.htm.

139 U. S. EPA. 1998. Toxicological Review of Naphthalene (Reassessment of the Inhalation Cancer Risk), 

Environmental Protection Agency, Integrated Risk Information System, Research and Development, 

National Center for Environmental Assessment, Washington, DC. This material is available electronically 

at http://www.epa.gov/iris/subst/0436.htm.

140 U. S. EPA. (1998). Toxicological Review of Naphthalene (Reassessment of the Inhalation Cancer 

Risk), Environmental Protection Agency, Integrated Risk Information System, Research and Development, 

National Center for Environmental Assessment, Washington, DC. This material is available electronically 

at http://www.epa.gov/iris/subst/0436.htm. 

141 Oak Ridge Institute for Science and Education. (2004). External Peer Review for the IRIS 

Reassessment of the Inhalation Carcinogenicity of Naphthalene. August 2004. 

http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=84403. 
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review draft does not represent official agency opinion and was released solely for the 

purposes of external peer review and public comment. The National Toxicology

Program listed naphthalene as "reasonably anticipated to be a human carcinogen" in 2004 

on the basis of bioassays reporting clear evidence of carcinogenicity in rats and some 

evidence of carcinogenicity in mice.142 California EPA has released a new risk 

assessment for naphthalene, and the IARC has reevaluated naphthalene and re-classified 

it as Group 2B: possibly carcinogenic to humans.143 

Naphthalene also causes a number of chronic non-cancer effects in animals, 

including abnormal cell changes and growth in respiratory and nasal tissues.144 The 

current EPA IRIS assessment includes noncancer data on hyperplasia and metaplasia in 

nasal tissue that form the basis of the inhalation RfC of 3 μg/m3.

145

 The ATSDR MRL

for acute exposure to naphthalene is 0.6 mg/kg/day.

ix. Other Air Toxics

In addition to the compounds described above, other compounds in gaseous 

hydrocarbon and PM emissions from motor vehicles will be affected by this action. 

Mobile source air toxic compounds that will potentially be impacted include 

ethylbenzene, propionaldehyde, toluene, and xylene. Information regarding the health 

effects of these compounds can be found in EPA’s IRIS database.146

b. Current Concentrations of Air Toxics 

The most recent available data indicate that the majority of Americans continue to 

be exposed to ambient concentrations of air toxics at levels which have the potential to 

cause adverse health effects.147 The levels of air toxics to which people are exposed vary

depending on where people live and work and the kinds of activities in which they

engage, as discussed in detail in U.S. EPA’s most recent Mobile Source Air Toxics 

Rule.148 According to the National Air Toxic Assessment (NATA) for 2005,149 mobile 

 

142 NTP. (2011). Report on Carcinogens, Twelfth Edition. Research Triangle Park, NC: U.S. Department of 

Health and Human Services, Public Health Service, National Toxicology Program. 499 pp.

143 International Agency for Research on Cancer (IARC). (2002). Monographs on the Evaluation of the 

Carcinogenic Risk of Chemicals for Humans. Vol. 82. Lyon, France. 

144 U. S. EPA. (1998). Toxicological Review of Naphthalene, Environmental Protection Agency, Integrated 

Risk Information System, Research and Development, National Center for Environmental Assessment, 

Washington, DC. This material is available electronically at http://www.epa.gov/iris/subst/0436.htm 

145 U.S. EPA. (1998). Toxicological Review of Naphthalene. Environmental Protection Agency, 

Integrated Risk Information System (IRIS), Research and Development, National Center for Environmental 

Assessment, Washington, DC http://www.epa.gov/iris/subst/0436.htm. 

146 U.S. EPA Integrated Risk Information System (IRIS) database is available at: www.epa.gov/iris 

147 U.S. EPA. (2011) Summary of Results for the 2005 National-Scale Assessment. 

www.epa.gov/ttn/atw/nata2005/05pdf/sum_results.pdf.

148 U. S. Environmental Protection Agency (2007). Control of Hazardous Air Pollutants from Mobile 

Sources; Final Rule. 72 FR 8434, February 26, 2007. 
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sources were responsible for 43 percent of outdoor toxic emissions and over 50 percent of 

the cancer risk and noncancer hazard associated with primary emissions. Mobile sources 

are also large contributors to precursor emissions which react to form secondary

concentrations of air toxics. Formaldehyde is the largest contributor to cancer risk of all 

80 pollutants quantitatively assessed in the 2005 NATA. Mobile sources were 

responsible for over 40 percent of primary emissions of this pollutant in 2005, and are 

major contributors to formaldehyde precursor emissions. Benzene is also a large 

contributor to cancer risk, and mobile sources account for over 70 percent of ambient 

exposure. Over the years, EPA has implemented a number of mobile source and fuel 

controls which have resulted in VOC reductions, which also reduced formaldehyde, 

benzene and other air toxic emissions.

6. Near-Roadway Pollution

Locations in close proximity to major roadways generally have elevated 

concentrations of many air pollutants emitted from motor vehicles. Hundreds of such 

studies have been published in peer-reviewed journals, concluding that concentrations of 

CO, NO, NO2, benzene, aldehydes, particulate matter, black carbon, and many other 

compounds are elevated in ambient air within approximately 300-600 meters (about 

1,000-2,000 feet) of major roadways. Highest concentrations of most pollutants emitted 

directly by motor vehicles are found at locations within 50 meters (about 165 feet) of the 

edge of a roadway’s traffic lanes.

A recent large-scale review of air quality measurements in vicinity of major 

roadways between 1978 and 2008 concluded that the pollutants with the steepest 

concentration gradients in vicinities of roadways were CO, ultrafine particles, metals, 

elemental carbon (EC), NO, NOX, and several VOCs.150 These pollutants showed a large 

reduction in concentrations within 100 meters downwind of the roadway. Pollutants that 

showed more gradual reductions with distance from roadways included benzene, NO2, 

PM2.5, and PM10. In the review article, results varied based on the method of statistical 

analysis used to determine the trend.

For pollutants with relatively high background concentrations relative to nearroad concentrations, detecting concentration gradients can be difficult. For example, 

many aldehydes have high background concentrations as a result of photochemical 

breakdown of precursors from many different organic compounds. This can make 

detection of gradients around roadways and other primary emission sources difficult. 

However, several studies have measured aldehydes in multiple weather conditions, and 

 

149 U. S. EPA. (2011). 2005 National-Scale Air Toxics Assessment. http://www.epa.gov/ttn/atw/nata2005/. 

150 Karner, A.A.; Eisinger, D.S.; Niemeier, D.A. (2010). Near-roadway air quality: synthesizing the 

findings from real-world data. Environ Sci Technol 44: 5334-5344.
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found higher concentrations of many carbonyls downwind of roadways.151,152 These 

findings suggest a substantial roadway source of these carbonyls.

In the past 15 years, many studies have been published with results reporting that 

populations who live, work, or go to school near high-traffic roadways experience higher 

rates of numerous adverse health effects, compared to populations far away from major 

roads.153 In addition, numerous studies have found adverse health effects associated with 

spending time in traffic, such as commuting or walking along high-traffic 

roadways.154,155,156,157 The health outcomes with the strongest evidence linking them with 

traffic-associated air pollutants are respiratory effects, particularly in asthmatic children, 

and cardiovascular effects.

Numerous reviews of this body of health literature have been published as well. 

In 2010, an expert panel of the Health Effects Institute (HEI) published a review of 

hundreds of exposure, epidemiology, and toxicology studies.158 The panel rated how the 

evidence for each type of health outcome supported a conclusion of a causal association 

with traffic-associated air pollution as either “sufficient,” “suggestive but not sufficient,” 

or “inadequate and insufficient.” The panel categorized evidence of a causal association 

for exacerbation of childhood asthma as “sufficient.” The panel categorized evidence of 

a causal association for new onset asthma as between “sufficient” and as “suggestive but 

not sufficient.” “Suggestive of a causal association” was how the panel categorized 

evidence linking traffic-associated air pollutants with exacerbation of adult respiratory

symptoms and lung function decrement. It categorized as “inadequate and insufficient” 

evidence of a causal relationship between traffic-related air pollution and health care 

utilization for respiratory problems, new onset adult asthma, chronic obstructive 

 

151 Liu, W.; Zhang, J.; Kwon, J.l; et l. (2006). Concentrations and source characteristics of airborne 

carbonyl compounds measured outside urban residences. J Air Waste Manage Assoc 56: 1196-1204.

152 Cahill, T.M.; Charles, M.J.; Seaman, V.Y. (2010). Development and application of a sensitive method to 

determine concentrations of acrolein and other carbonyls in ambient air. Health Effects Institute Research 

Report 149.Available at http://dx.doi.org

153 In the widely-used PubMed database of health publications, between January 1, 1990 and August 18, 

2011, 605 publications contained the keywords “traffic, pollution, epidemiology,” with approximately half 

the studies published after 2007. 

154 Laden, F.; Hart, J.E.; Smith, T.J.; Davis, M.E.; Garshick, E. (2007) Cause-specific mortality in the 

unionized U.S. trucking industry. Environmental Health Perspect 115:1192-1196.

155 Peters, A.; von Klot, S.; Heier, M.; Trentinaglia, I.; Hörmann, A.; Wichmann, H.E.; Löwel, H. (2004) 

Exposure to traffic and the onset of myocardial infarction. New England J Med 351: 1721-1730.

156 Zanobetti, A.; Stone, P.H.; Spelzer, F.E.; Schwartz, J.D.; Coull, B.A.; Suh, H.H.; Nearling, B.D.; 

Mittleman, M.A.; Verrier, R.L.; Gold, D.R. (2009) T-wave alternans, air pollution and traffic in high-risk 

subjects. Am J Cardiol 104: 665-670.

157 Dubowsky Adar, S.; Adamkiewicz, G.; Gold, D.R.; Schwartz, J.; Coull, B.A.; Suh, H. (2007) Ambient 

and microenvironmental particles and exhaled nitric oxide before and after a group bus trip. Environ 

Health Perspect 115: 507-512.

158 Health Effects Institute Panel on the Health Effects of Traffic-Related Air Pollution. (2010). Trafficrelated air pollution: a critical review of the literature on emissions, exposure, and health effects. HEI 

Special Report 17. Available at http://www.healtheffects.org
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pulmonary disease (COPD), nonasthmatic respiratory allergy, and cancer in adults and 

children. Other literature reviews have been published with conclusions similar to the 

HEI panel’s.159,160,161 Health outcomes with few publications suggest the possibility of 

other effects still lacking sufficient evidence to draw definitive conclusions. Among 

these outcomes with a small number of positive studies are neurological impacts (e.g., 

autism and reduced cognitive function) and reproductive outcomes (e.g., preterm birth, 

low birth weight).162,163,164,165

In addition to health outcomes, particularly cardiopulmonary effects, conclusions 

of numerous studies suggest mechanisms by which traffic-related air pollution affects 

health. Numerous studies indicate that near-roadway exposures may increase systemic 

inflammation, affecting organ systems, including blood vessels and lungs.166,167,168,169 

Long-term exposures in near-road environments have been associated with inflammationassociated conditions, such as atherosclerosis and asthma.170,171,172

 

 

159 Boothe, V.L.; Shendell, D.G. (2008). Potential health effects associated with residential proximity to 

freeways and primay roads: review of scientific literature, 1999-2006. J Environ Health 70: 33-41.

160 Salam, M.T.; Islam, T.; Gilliland, F.D. (2008). Recent evidence for adverse effects of residential 

proximity to traffic sources on asthma. Curr Opin Pulm Med 14: 3-8.

161 Raaschou-Nielsen, O.; Reynolds, P. (2006). Air pollution and childhood cancer: a review of the 

epidemiological literature. Int J Cancer 118: 2920-9.

162 Volk, H.E.; Hertz-Picciotto, I.; Delwiche, L.; et al. (2011). Residential proximity to freeways and autism 

in the CHARGE study. Environ Health Perspect 119: 873-877.

163 Franco-Suglia, S.; Gryparis, A.; Wright, R.O.; et al. (2007). Association of black carbon with cognition 

among children in a prospective birth cohort study. Am J Epidemiol. doi: 10.1093/aje/kwm308. [Online at 

http://dx.doi.org]

164 Power, M.C.; Weisskopf, M.G.; Alexeef, S.E.; et al. (2011). Traffic-related air pollution and cognitive 

function in a cohort of older men. Environ Health Perspect 2011: 682-687.

165 Wu, J.; Wilhelm, M.; Chung, J.; et al. (2011). Comparing exposure assessment methods for trafficrelated air pollution in and adverse pregnancy outcome study. Environ Res 111: 685-6692.

166 Riediker, M. (2007). Cardiovascular effects of fine particulate matter components in highway patrol 

officers. Inhal Toxicol 19: 99-105. doi: 10.1080/08958370701495238 Available at http://dx.doi.org

167 Alexeef, S.E.; Coull, B.A.; Gryparis, A.; et al. (2011). Medium-term exposure to traffic-related air 

pollution and markers of inflammation and endothelial function. Environ Health Perspect 119: 481-486. 

doi:10.1289/ehp.1002560 Available at http://dx.doi.org

168 Eckel. S.P.; Berhane, K.; Salam, M.T.; et al. (2011). Traffic-related pollution exposure and exhaled 

nitric oxide in the Children’s Health Study. Environ Health Perspect (IN PRESS). 

doi:10.1289/ehp.1103516. Available at http://dx.doi.org

169 Zhang, J.; McCreanor, J.E.; Cullinan, P.; et al. (2009). Health effects of real-world exposure diesel 

exhaust in persons with asthma. Res Rep Health Effects Inst 138. [Online at http://www.healtheffects.org]

170 Adar, S.D.; Klein, R.; Klein, E.K.; et al. (2010). Air pollution and the microvasculatory: a crosssectional assessment of in vivo retinal images in the population-based Multi-Ethnic Study of 

Atherosclerosis. PLoS Med 7(11): E1000372. doi:10.1371/journal.pmed.1000372. Available at 

http://dx.doi.org

171 Kan, H.; Heiss, G.; Rose, K.M.; et al. (2008). Proxpective analysis of traffic exposure as a risk factor for 

incident coronary heart disease: the Atherosclerosis Risk in Communities (ARIC) study. Environ Health 

Perspect 116: 1463-1468. doi:10.1289/ehp.11290. Available at http://dx.doi.org
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Several studies suggest that some factors may increase susceptibility to the effects 

of traffic-associated air pollution. Several studies have found stronger respiratory

associations in children experiencing chronic social stress, such as in violent 

neighborhoods or in homes with high family stress.173,174,175 

The risks associated with residence, workplace, or schools near major roads are of 

potentially high public health significance due to the large population in such locations. 

According to the 2009 American Housing Survey, over 22 million homes (17.0 percent 

of all U.S. housing units) were located within 300 feet of an airport, railroad, or highway

with four or more lanes. This corresponds to a population of more than 50 million U.S. 

residents in close proximity to high-traffic roadways or other transportation sources. 

Based on 2010 Census data, a 2013 publication estimated that 19 percent of the U.S. 

population (over 59 million people) lived within 500 meters of roads with at least 25,000 

annual average daily traffic (AADT), while about 3.2 percent of the population lived 

within 100 meters (about 300 feet) of such roads.176 Another 2013 study estimated that 

3.7 percent of the U.S. population (about 11.3 million people) lived within 150 meters 

(about 500 feet) of interstate highways, or other freeways and expressways.177 As 

discussed in Section III, on average, populations near major roads have higher fractions 

of minority residents and lower socioeconomic status. Furthermore, on average, 

Americans spend more than an hour traveling each day, bringing nearly all residents into 

a high-exposure microenvironment for part of the day.

In light of these concerns, EPA has required and is working with states to ensure 

that air quality monitors be placed near high-traffic roadways for determining NAAQS 

compliance for CO, NO2, and PM2.5 (in addition to those existing monitors located in 

neighborhoods and other locations farther away from pollution sources). Near-roadway

monitors for NO2 begin operation between 2014 and 2017 in Core Based Statistical Areas 

(CBSAs) with population of at least 500,000. Monitors for CO and PM2.5 begin 

operation between 2015 and 2017. These monitors will further our understanding of 

exposure in these locations.

 

172 McConnell, R.; Islam, T.; Shankardass, K.; et al. (2010). Childhood incident asthma and traffic-related 

air pollution at home and school. Environ Health Perspect 1021-1026.

173 Islam, T.; Urban, R.; Gauderman, W.J.; et al. (2011). Parental stress increases the detrimental effect of 

traffic exposure on children’s lung function. Am J Respir Crit Care Med (In press) 

174 Clougherty, J.E.; Levy, J.I.; Kubzansky, L.D.; et al. (2007). Synergistic effects of traffic-related air 

pollution and exposure to violence on urban asthma etiology. Environ Health Perspect 115: 1140-1146.

175 Chen, E.; Schrier, H.M.; Strunk, R.C.; et al. (2008). Chronic traffic-related air pollution and stress 

interact to predict biologic and clinical outcomes in asthma. Environ Health Perspect 116: 970-5.

176 Rowangould, G.M. (2013) A census of the US near-roadway population: public health and 

environmental justice considerations. Transportation Research Part D 25: 59-67.

177 Boehmer, T.K.; Foster, S.L.; Henry, J.R.; Woghiren-Akinnifesi, E.L.; Yip, F.Y. (2013) Residential 

proximity to major highways – United States, 2010. Morbidity and Mortality Weekly Report 62(3);46-50.
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EPA continues to research near-road air quality, including the types of pollutants 

found in high concentrations near major roads and health problems associated with the 

mixture of pollutants near roads. 

7. Environmental Impacts of Motor Vehicles and Fuels

a. Plant and Ecosystem Effects of Ozone

The welfare effects of ozone can be observed across a variety of scales, i.e. 

subcellular, cellular, leaf, whole plant, population and ecosystem. Ozone effects that 

begin at small spatial scales, such as the leaf of an individual plant, when they occur at 

sufficient magnitudes (or to a sufficient degree) can result in effects being propagated 

along a continuum to larger and larger spatial scales. For example, effects at the 

individual plant level, such as altered rates of leaf gas exchange, growth and reproduction 

can, when widespread, result in broad changes in ecosystems, such as productivity, 

carbon storage, water cycling, nutrient cycling, and community composition.

Ozone can produce both acute and chronic injury in sensitive species depending 

on the concentration level and the duration of the exposure.178 In those sensitive 

species179, effects from repeated exposure to ozone throughout the growing season of the 

plant tend to accumulate, so that even low concentrations experienced for a longer 

duration have the potential to create chronic stress on vegetation.

180

 Ozone damage to 

sensitive species includes impaired photosynthesis and visible injury to leaves. The 

impairment of photosynthesis, the process by which the plant makes carbohydrates (its 

source of energy and food), can lead to reduced crop yields, timber production, and plant 

productivity and growth. Impaired photosynthesis can also lead to a reduction in root 

growth and carbohydrate storage below ground, resulting in other, more subtle plant and 

ecosystems impacts.181 These latter impacts include increased susceptibility of plants to 

insect attack, disease, harsh weather, interspecies competition and overall decreased plant 

vigor. The adverse effects of ozone on areas with sensitive species could potentially lead 

to species shifts and loss from the affected ecosystems,

182 resulting in a loss or reduction 

 

178 73 FR 16486 (March 27, 2008).

179 73 FR 16491 (March 27, 2008). Only a small percentage of all the plant species growing within the U.S. 

(over 43,000 species have been catalogued in the USDA PLANTS database) have been studied with respect 

to ozone sensitivity.

180 The concentration at which ozone levels overwhelm a plant’s ability to detoxify or compensate for 

oxidant exposure varies. Thus, whether a plant is classified as sensitive or tolerant depends in part on the 

exposure levels being considered. Chapter 9, section 9.3.4 of U.S. EPA, 2013 Integrated Science 

Assessment for Ozone and Related Photochemical Oxidants. Office of Research and 

Development/National Center for Environmental Assessment. U.S. Environmental Protection Agency. 

EPA 600/R-10/076F.

181 73 FR 16492 (March 27, 2008).

182 73 FR 16493/16494 (March 27, 2008), Per footnote 2 above, ozone impacts could be occurring in areas 

where plant species sensitive to ozone have not yet been studied or identified. 
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in associated ecosystem goods and services. Additionally, visible ozone injury to leaves 

can result in a loss of aesthetic value in areas of special scenic significance like national 

parks and wilderness areas and reduced use of sensitive ornamentals in landscaping.

183

 

The Integrated Science Assessment (ISA) for Ozone presents more detailed 

information on how ozone effects vegetation and ecosystems.184 The ISA concludes that 

ambient concentrations of ozone are associated with a number of adverse welfare effects 

and characterizes the weight of evidence for different effects associated with ozone.185 

The ISA concludes that visible foliar injury effects on vegetation, reduced vegetation 

growth, reduced productivity in terrestrial ecosystems, reduced yield and quality of 

agricultural crops, and alteration of below-ground biogeochemical cycles are causally 

associated with exposure to ozone. It also concludes that reduced carbon sequestration in 

terrestrial ecosystems, alteration of terrestrial ecosystem water cycling, and alteration of 

terrestrial community composition are likely to be causally associated with exposure to 

ozone. 

b. Visibility

Visibility can be defined as the degree to which the atmosphere is transparent to 

visible light.186 Visibility impairment is caused by light scattering and absorption by

suspended particles and gases. Visibility is important because it has direct significance to 

people’s enjoyment of daily activities in all parts of the country. Individuals value good 

visibility for the well-being it provides them directly, where they live and work, and in 

places where they enjoy recreational opportunities. Visibility is also highly valued in 

significant natural areas, such as national parks and wilderness areas, and special 

emphasis is given to protecting visibility in these areas. For more information on 

visibility see the final 2009 PM ISA.187

 

183 73 FR 16490/ 16497 (March 27, 2008).

184 U.S. EPA. Integrated Science Assessment of Ozone and Related Photochemical Oxidants (Final 

Report). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-10/076F, 2013. The ISA is 

available at http://cfpub.epa.gov/ncea/isa/recordisplay.cfm?deid=247492#Download

185 The Ozone ISA evaluates the evidence associated with different ozone related health and welfare

effects, assigning one of five “weight of evidence” determinations: causal relationship, likely to be a causal 

relationship, suggestive of a causal relationship, inadequate to infer a causal relationship, and not likely to 

be a causal relationship. For more information on these levels of evidence, please refer to Table II of the 

ISA. 

186 National Research Council, (1993). Protecting Visibility in National Parks and Wilderness Areas. 

National Academy of Sciences Committee on Haze in National Parks and Wilderness Areas. National 

Academy Press, Washington, DC. This book can be viewed on the National Academy Press Website at 

http://www.nap.edu/books/0309048443/html/

187 U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. 

Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F. 
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EPA is working to address visibility impairment. In 1999, EPA finalized the 

regional haze program to protect the visibility in Mandatory Class I Federal areas.188 

There are 156 national parks, forests and wilderness areas categorized as Mandatory

Class I Federal areas.189 These areas are defined in CAA section 162 as those national 

parks exceeding 6,000 acres, wilderness areas and memorial parks exceeding 5,000 acres, 

and all international parks which were in existence on August 7, 1977. EPA has also 

concluded that PM2.5 causes adverse effects on visibility in other areas that are not 

protected by the Regional Haze Rule, depending on PM2.5 concentrations and other 

factors that control their visibility impact effectiveness such as dry chemical composition 

and relative humidity (i.e., an indicator of the water composition of the particles). EPA 

revised the PM2.5 standards in December 2012 and established a target level of protection 

that is expected to be met through attainment of the existing secondary standards for 

PM2.5. 

i. Current Visibility Levels

As mentioned in Section II.B.2.c, millions of people live in nonattainment areas 

for the PM2.5 NAAQS. These populations, as well as large numbers of individuals who 

travel to these areas, are likely to experience visibility impairment. In addition, while 

visibility trends have improved in mandatory class I federal areas, the most recent data 

show that these areas continue to suffer from visibility impairment. In summary, 

visibility impairment is experienced throughout the U.S., in multi-state regions, urban 

areas, and remote mandatory class I federal areas.

c. Atmospheric Deposition

Wet and dry deposition of ambient particulate matter delivers a complex mixture 

of metals (e.g., mercury, zinc, lead, nickel, aluminum, cadmium), organic compounds 

(e.g., polycyclic organic matter, dioxins, furans) and inorganic compounds (e.g., nitrate, 

sulfate) to terrestrial and aquatic ecosystems. The chemical form of the compounds 

deposited depends on a variety of factors including ambient conditions (e.g., temperature, 

humidity, oxidant levels) and the sources of the material. Chemical and physical 

transformations of the compounds occur in the atmosphere as well as the media onto 

which they deposit. These transformations in turn influence the fate, bioavailability and 

potential toxicity of these compounds. Atmospheric deposition has been identified as a 

key component of the environmental and human health hazard posed by several 

pollutants including mercury, dioxin and PCBs.190

 

188 64 FR 35714 (July 1, 1999). 

189 62 FR 38680-38681 (July 18, 1997).

190 U.S. EPA. (2000). Deposition of Air Pollutants to the Great Waters: Third Report to Congress. Office of 

Air Quality Planning and Standards. EPA-453/R-00-0005. 
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Adverse impacts on water quality can occur when atmospheric contaminants 

deposit to the water surface or when material deposited on the land enters a waterbody 

through runoff. Potential impacts of atmospheric deposition to waterbodies include those 

related to both nutrient and toxic inputs. Adverse effects to human health and welfare 

can occur from the addition of excess nitrogen via atmospheric deposition. The nitrogennutrient enrichment contributes to toxic algae blooms and zones of depleted oxygen, 

which can lead to fish kills, frequently in coastal waters. Deposition of heavy metals or 

other toxics may lead to the human ingestion of contaminated fish, impairment of 

drinking water, damage to freshwater and marine ecosystem components, and limits to 

recreational uses. Several studies have been conducted in U.S. coastal waters and in the 

Great Lakes Region in which the role of ambient PM deposition and runoff is 

investigated.191,192,193,194,195 

Atmospheric deposition of nitrogen and sulfur contributes to acidification, 

altering biogeochemistry and affecting animal and plant life in terrestrial and aquatic 

ecosystems across the United States. The sensitivity of terrestrial and aquatic ecosystems 

to acidification from nitrogen and sulfur deposition is predominantly governed by

geology. Prolonged exposure to excess nitrogen and sulfur deposition in sensitive areas 

acidifies lakes, rivers and soils. Increased acidity in surface waters creates inhospitable 

conditions for biota and affects the abundance and nutritional value of preferred prey

species, threatening biodiversity and ecosystem function. Over time, acidifying

deposition also removes essential nutrients from forest soils, depleting the capacity of 

soils to neutralize future acid loadings and negatively affecting forest sustainability. 

Major effects include a decline in sensitive forest tree species, such as red spruce (Picea 

rubens) and sugar maple (Acer saccharum), and a loss of biodiversity of fishes, 

zooplankton, and macro invertebrates.

In addition to the role nitrogen deposition plays in acidification, nitrogen 

deposition also leads to nutrient enrichment and altered biogeochemical cycling. In 

aquatic systems increased nitrogen can alter species assemblages and cause 

eutrophication. In terrestrial systems nitrogen loading can lead to loss of nitrogen 

sensitive lichen species, decreased biodiversity of grasslands, meadows and other 

sensitive habitats, and increased potential for invasive species. For a broader explanation 

of the topics treated here, refer to the description in Section 6.3.2 of the RIA.

 

191 U.S. EPA. (2004). National Coastal Condition Report II. Office of Research and Development/ Office of 

Water. EPA-620/R-03/002. 

192 Gao, Y., E.D. Nelson, M.P. Field, et al. (2002). Characterization of atmospheric trace elements on 

PM2.5 particulate matter over the New York-New Jersey harbor estuary. Atmos. Environ. 36: 1077-1086. 

193 Kim, G., N. Hussain, J.R. Scudlark, and T.M. Church. (2000). Factors influencing the atmospheric 

depositional fluxes of stable Pb, 210Pb, and 7Be into Chesapeake Bay. J. Atmos. Chem. 36: 65-79. 

194 Lu, R., R.P. Turco, K. Stolzenbach, et al. (2003). Dry deposition of airborne trace metals on the Los 

Angeles Basin and adjacent coastal waters. J. Geophys. Res. 108(D2, 4074): AAC 11-1 to 11-24. 

195 Marvin, C.H., M.N. Charlton, E.J. Reiner, et al. (2002). Surficial sediment contamination in Lakes Erie 

and Ontario: A comparative analysis. J. Great Lakes Res. 28(3): 437-450. 
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Adverse impacts on soil chemistry and plant life have been observed for areas 

heavily influenced by atmospheric deposition of nutrients, metals and acid species, 

resulting in species shifts, loss of biodiversity, forest decline, damage to forest 

productivity and reductions in ecosystem services. Potential impacts also include adverse 

effects to human health through ingestion of contaminated vegetation or livestock (as in 

the case for dioxin deposition), reduction in crop yield, and limited use of land due to 

contamination. 

Atmospheric deposition of pollutants can reduce the aesthetic appeal of buildings 

and culturally important articles through soiling, and can contribute directly (or in 

conjunction with other pollutants) to structural damage by means of corrosion or erosion. 

Atmospheric deposition may affect materials principally by promoting and accelerating 

the corrosion of metals, by degrading paints, and by deteriorating building materials such 

as concrete and limestone. Particles contribute to these effects because of their 

electrolytic, hygroscopic, and acidic properties, and their ability to adsorb corrosive gases 

(principally sulfur dioxide). 
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i. Current Nitrogen and Sulfur Deposition

Over the past two decades, the EPA has undertaken numerous efforts to reduce 

nitrogen and sulfur deposition across the U.S. Analyses of long-term monitoring data for 

the U.S. show that deposition of both nitrogen and sulfur compounds has decreased over 

the last 19 years.196 The data show that reductions were more substantial for sulfur 

compounds than for nitrogen compounds. In the eastern U.S., where data are most 

abundant, total sulfur deposition decreased by about 44 percent between 1990 and 2007, 

while total nitrogen deposition decreased by 25 percent over the same time frame.197 

These numbers are generated by the U.S. national monitoring network and they likely

underestimate nitrogen deposition because neither ammonia nor organic nitrogen is 

measured. Although total nitrogen and sulfur deposition has decreased over time, many

areas continue to be negatively impacted by deposition. Deposition of inorganic nitrogen 

and sulfur species routinely measured in the U.S. between 2005 and 2007 were as high as 

9.6 kilograms of nitrogen per hectare (kg N/ha) averaged over three years and 20.8 

kilograms of sulfur per hectare (kg S/ha) averaged over three years.198

d. Environmental Effects of Air Toxics

Emissions from producing, transporting and combusting fuel contribute to 

ambient levels of pollutants that contribute to adverse effects on vegetation. Volatile 

organic compounds, some of which are considered air toxics, have long been suspected to 

play a role in vegetation damage.199 In laboratory experiments, a wide range of tolerance 

to VOCs has been observed.200 Decreases in harvested seed pod weight have been 

reported for the more sensitive plants, and some studies have reported effects on seed 

germination, flowering and fruit ripening. Effects of individual VOCs or their role in 

conjunction with other stressors (e.g., acidification, drought, temperature extremes) have 

not been well studied. In a recent study of a mixture of VOCs including ethanol and 

 

196 U.S. EPA. (2013). U.S. EPA’s Report on the Environment. Data accessed online November 25, 2013 at: 

http://cfpub.epa.gov/eroe/index.cfm?fuseaction=detail.viewInd&lv=list.listBySubTopic&r=216610&subto

p=341&ch=46. 

197 U.S. EPA. (2012). U.S. EPA’s Report on the Environment. Data accessed online February 15, 2012 at: 

http://cfpub.epa.gov/eroe/index.cfm?fuseaction=detail.viewPDF&ch=46&lShowInd=0&subtop=341&lv=li

st.listByChapter&r=216610. 

198 U.S. EPA. (2012). U.S. EPA's Report on the Environment. Data accessed online February 15, 2012 at: 

http://cfpub.epa.gov/eroe/index.cfm?fuseaction=detail.viewPDF&ch=46&lShowInd=0&subtop=341&lv=li

st.listByChapter&r=216610. 

199 U.S. EPA. (1991). Effects of organic chemicals in the atmosphere on terrestrial plants. EPA/600/3-

91/001. 

200 Cape JN, ID Leith, J Binnie, J Content, M Donkin, M Skewes, DN Price AR Brown, AD Sharpe. 

(2003). Effects of VOCs on herbaceous plants in an open-top chamber experiment. Environ. Pollut. 

124:341-343. 
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toluene on herbaceous plants, significant effects on seed production, leaf water content 

and photosynthetic efficiency were reported for some plant species.201

Research suggests an adverse impact of vehicle exhaust on plants, which has in 

some cases been attributed to aromatic compounds and in other cases to nitrogen 

oxides.202,203, 204

III. How Would This Rule Reduce Emissions and Air

Pollution?

A. Effects of the Vehicle and Fuel Changes on Mobile Source Emissions

The Tier 3 vehicle and fuel standards will significantly reduce the tailpipe and 

evaporative emissions of light- and heavy-duty vehicles in several ways, as described in 

this section. In addition, the gasoline sulfur standard will reduce emissions of SO2 from 

existing gasoline-powered vehicles and equipment. As described in Section II, all of 

these emission reductions will in turn improve air quality nationwide and reduce the 

health effects associated with air pollution from mobile sources.

As with the Tier 2 program, EPA is implementing closely-coordinated 

requirements for both automakers and refiners in the same rulemaking action. The Tier 3 

vehicle emission standards and gasoline sulfur standards represent a “systems approach” 

to reducing vehicle-related exhaust and evaporative emissions. By recognizing the 

relationships among the various sources of emissions addressed by this action, we have 

been able to integrate the provisions into a single, coordinated program. 

1. How Do Vehicles Produce the Emissions Addressed in this Action?

The degree to which vehicles produce exhaust and evaporative emissions depends 

on the design and functionality of the engine and the associated exhaust and evaporative 

emission controls, in concert with the properties of the fuel on which the vehicle is 

operating. In the following paragraphs, we discuss how light- and heavy-duty vehicles 

produce each of these types of emissions, both from the tailpipe and from the fuel system. 

 

201 Cape JN, ID Leith, J Binnie, J Content, M Donkin, M Skewes, DN Price AR Brown, AD Sharpe. 

(2003). Effects of VOCs on herbaceous plants in an open-top chamber experiment. Environ. Pollut. 

124:341-343. 

202 Viskari E-L. (2000). Epicuticular wax of Norway spruce needles as indicator of traffic pollutant 

deposition. Water, Air, and Soil Pollut. 121:327-337. 

203 Ugrekhelidze D, F Korte, G Kvesitadze. (1997). Uptake and transformation of benzene and toluene by 

plant leaves. Ecotox. Environ. Safety 37:24-29. 

204 Kammerbauer H, H Selinger, R Rommelt, A Ziegler-Jons, D Knoppik, B Hock. (1987). Toxic 

components of motor vehicle emissions for the spruce Picea abies. Environ. Pollut. 48:235-243. 
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a. Tailpipe (Exhaust) Emissions

The pollutants emitted at the vehicle’s tailpipe and their quantities depend on 

how the fuel is combusted in the engine and how the resulting gases are treated in the 

exhaust system. Historically, much of tailpipe emission control has focused on 

hydrocarbon compounds (HC) and NOX. The portion of hydrocarbons that is methane is 

minimally reactive in forming ozone. Thus, for emission control purposes, the focus is 

generally on non-methane hydrocarbons (NMHC), which are also expressed as nonmethane organic gases (NMOG) in order to account for oxygenates (usually ethanol) now 

usually present in the fuel. 

Tailpipe hydrocarbon emissions also include several toxic pollutants, including 

benzene, acetaldehyde, and formaldehyde. To varying degrees, the mass emissions of 

these pollutants are reduced along with other hydrocarbons by the catalytic converter and 

improved engine controls. 

Light- and heavy-duty gasoline vehicles also emit PM and CO. PM forms 

directly as a combustion product (as elemental carbon or soot) and indirectly as semivolatile hydrocarbon compounds that form particles in the exhaust system or soon after 

exiting the tailpipe. CO is a product of incomplete fuel combustion.

When operating properly, modern exhaust emission controls (centering on the 

catalytic convertor) can reduce much of the HC (including toxics), NOX and CO exiting 

the engine. However, tailpipe emissions are increased during periods of vehicle startup, 

as catalytic convertors must warm up to be effective; during subsequent operation due to 

the interference of sulfur in the gasoline; during high load operating events, as the 

catalyst is overwhelmed or its operation is modified to protect against permanent damage; 

and as a vehicle ages, as the catalyst degrades in performance due to the effects of high 

temperature operation and contaminants in the fuel and lubricating oil. 

b. Evaporative Emissions

Gasoline vehicles also produce vapors in the fuel tank and fuel system that can be 

released as evaporative emissions. These vapors are primarily the lighter, more volatile 

hydrocarbon compounds in gasoline. As discussed in Section IV below, vehicle 

evaporative (“evap”) control systems are designed to block or capture vapors as they are 

generated. Vapors are generated in the vehicle fuel tank and fuel system (and released to 

the atmosphere if not adequately controlled) as fuel heats up due to ambient temperature 

increase and/or vehicle operation. Fuel vapors are also released when they permeate 

through elastomers in the fuel system, when they leak at connections or due to damaged 

components, and during refueling events. 

In general, the evap emission controls on current vehicles (and that will be 

improved under this action) consist of a canister filled with activated charcoal and 

connected by hoses to the fuel system. The hoses direct generated vapors to the canister, 
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which collects the vapors on the carbon and stores them until the system experiences a 

“purge” event. During purge, the engine draws fresh air through the canister, carrying 

vapors released by the carbon to the engine to be combusted and restoring the capacity of 

the canister. Evaporative emissions occur when vapors are emitted to the atmosphere 

because the evap system is compromised, the carbon canister is overwhelmed, or vapors 

permeate or leak. As such, evaporative emission controls also involve proper material 

selection for fuel system components, careful design of these components, and onboard 

diagnostics to check the system for failure. 

2. How Will the Changes to Gasoline Sulfur Content Affect Vehicle Emissions?

Gasoline vehicles rely on highly efficient aftertreatment catalysts to control 

tailpipe emissions of harmful pollutants like CO and NOX, as well as VOCs that include 

air toxics and precursor compounds to ozone and secondary PM in the atmosphere. 

These catalysts utilize finely-dispersed precious metals that are susceptible to 

deactivation by sulfur compounds in the exhaust. Studies have repeatedly demonstrated 

that the presence of even a tiny amount of sulfur in fuel has a measurable impact on the 

ability of the catalyst to control emissions, and that emission levels of most pollutants, 

especially NOx, are very sensitive to fuel sulfur.205,206 

Sulfur naturally occurs in crude oil and is carried through the refining process into 

gasoline. EPA’s Tier 2 rulemaking for light-duty vehicles, published in 2000, required 

refiners to reduce sulfur levels in gasoline to an average of 30 ppm, a reduction of about 

90 percent from the in-use baseline. At the time, there were indications that sulfur 

reductions below 30 ppm may provide additional emission benefits. However, the data 

was insufficient to quantify the benefits to the existing fleet, and the Tier 2 vehicle 

standards could be achieved without lowering sulfur below 30 ppm.207

As discussed in Section IV.A.6, subsequent research provides a compelling case 

that even this level of sulfur degrades the emission performance of vehicles on the road 

today and inhibits necessary further reductions in vehicle emissions performance, which 

depend on optimum catalyst performance to reach emission targets. A study conducted 

by EPA and the auto industry in support of the Mobile Source Air Toxics (MSAT) rule 

found significant reductions in NOX, CO and total HC when nine Tier 2 vehicles were 

tested on ultra-low sulfur fuel.208 In particular, the study found a 32 percent decrease in 

NOX when sulfur was reduced from 32 ppm to 6 ppm (equivalent to a 25 percent

 

205 The Effects of Ultra-Low Sulfur Gasoline on Emissions from Tier 2 Vehicles in the In-Use Fleet, EPA420-R-14-002.

206 Durbin, T., “The Effect of Fuel Sulfur on NH3 and Other Emissions from 2000-2001 Model Year 

Vehicles”, May 2003. Published as Report E-60 by the Coordinating Research Council, Alpharetta, GA.

207 65 FR 6698 (February 10, 2000)

208 Regulatory Impact Analysis for the Control of Hazardous Air Pollutants from Mobile Sources Final 

Rule, EPA 420-R-07-002, Chapter 6
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decrease if sulfur levels were reduced from 30 to 10 ppm, assuming a linear effect). 

Another recent study by Umicore showed reductions of 41 percent for NOX and 17 

percent for hydrocarbons on a PZEV operating on fuel with 33 ppm and 3 ppm fuel 

(equivalent to reductions of 27 percent and 11 percent, respectively, if sulfur levels were 

reduced from 30 to 10 ppm, assuming a linear effect).209 

A larger study of Tier 2 vehicles recently completed by EPA confirmed these 

results, showing significant reductions in FTP-composite NOX (14 percent), CO (10 

percent) and total HC (15 percent) on the 5 ppm fuel, relative to 28 ppm fuel (equivalent 

to 12 percent, 9 percent, and 13 percent reduction, respectively, if sulfur levels were 

reduced from 30 to 10 ppm, assuming a linear effect).210 For NOX, the majority of 

overall reductions were driven by large reductions on warmed-up periods of the test cycle 

(Bag 2), which showed a 52 percent reduction using 5 ppm fuel relative to 28 ppm fuel 

(equivalent to 45 percent reduction if sulfur levels were reduced from 30 to 10 ppm, 

assuming a linear effect), consistent with the role of sulfur in catalyst degradation 

discussed above. For additional details regarding these results, please see Section 

IV.A.6.c.

Our application of these study results assumes a linear effect of sulfur level on 

catalyst efficiency between the high and low sulfur test fuels. This is reasonable given 

that the mass flow rate of sulfur in exhaust gas changes in proportion to its concentration 

in the fuel, and that the chemical kinetics of adsorption of sulfur to the precious metal 

sites is approximately first order. Linearity of effect is also supported by past studies 

with multiple fuel sulfur levels such as the CRC E-60 and 2000 AAM/AIAM/Oil 

Industry emission test programs.211,212

Based on these analyses, the benefits of the Tier 3 sulfur standard are significant 

in two ways: they enable vehicles designed to the Tier 3 tailpipe exhaust standards to 

meet these standards for the duration of their useful life, and they facilitate immediate 

emission reductions from all the vehicles on the road at the time the sulfur controls are 

implemented. 

B. How Will Emissions Be Reduced?

The Tier 3 standards will reduce emissions of VOC, NOX (including NO2), direct 

PM2.5, CO, SO2, and air toxics. The sulfur standards will reduce emissions from the on-

 

209 Ball D., Clark D., Moser D. (2011), Effects of Fuel Sulfur on FTP NOx Emissions from a PZEV 4 

Cylinder Application. SAE 2011 World Congress Paper 2011-01-0300

210 The Effects of Ultra-Low Sulfur Gasoline on Emissions from Tier 2 Vehicles in the In-Use Fleet, EPA420-R-14-002. 

211 Durbin, T., “The Effect of Fuel Sulfur on NH3 and Other Emissions from 2000-2001 Model Year 

Vehicles”, May 2003. Published as Report E-60 by the Coordinating Research Council, Alpharetta, GA.

212 “AAM/AIAM/Oil Industry Low Sulfur & Oxygenate Test Program”, 2000, last accessed on 01/15/14 at 

the following URL: http://www.arb.ca.gov/fuels/gasoline/carfg3/aam_prstn.pdf.
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road fleet immediately upon implementation in calendar year 2017. The vehicle 

standards will begin to reduce emissions as the cleaner cars and trucks begin to enter the 

fleet in model year 2017 and model year 2018, respectively. The magnitude of reduction 

will grow as more Tier 3 vehicles enter the fleet. We present emission reductions in 

calendar year 2018 to reflect the early reductions expected from the Tier 3 standards, and 

in calendar year 2030, when 70 percent of the miles travelled are from vehicles that meet 

the fully phased-in Tier 3 standards. Although 2030 is the farthest year that is feasible 

for air quality modeling, the full reduction of the vehicle program will be realized after 

2030, when the fleet has fully turned over to vehicles that meet the fully phased-in Tier 3 

standards; thus we present emission reductions projected in 2050 as well (see Chapter 7 

of the RIA). 

Emission reductions are estimated on an annual basis, for all 50 U.S. states plus 

the District of Columbia, Puerto Rico and the U.S. Virgin Islands. The reductions were 

estimated using a version of EPA’s MOVES model updated for this analysis, as described 

in detail in Chapter 7 of the RIA. This version of MOVES includes our most recent data 

on how vehicle emissions are affected by changes in sulfur, ethanol, RVP, and other fuel

properties. We estimated emission reductions compared to a reference case that assumed 

renewable fuel volumes and ethanol blends based on the U.S. Energy Information 

Administration’s Annual Energy Outlook 2013 (AEO2013).213 As described in Chapter 7 

of the RIA, the reference and control scenarios based on AEO2013 reflect a mix of E10, 

E15, and E85 in both 2018 and 2030. The reference case assumed an average sulfur level 

of 30 ppm (10 ppm in California) and continuation of the Tier 2 vehicle program 

indefinitely, with the exception of California and Section 177 states that have adopted the 

LEV III program.

The analysis described here accounts for the following national onroad rules:

 Tier 2 Motor Vehicle Emissions Standards and Gasoline Sulfur Control 

Requirements (65 FR 6698, February 10, 2000)

 Heavy-Duty Engine and Vehicle Standards and Highway Diesel Fuel 

Sulfur Control Requirements (66 FR 5002, January 18, 2001)

 Mobile Source Air Toxics Rule (72 FR 8428, February 26, 2007)

 Regulation of Fuels and Fuel Additives: Changes to Renewable Fuel 

Standard Program (75 FR 14670, March 26, 2010)

 Light-Duty Vehicle Greenhouse Gas Emission Standards and Corporate 

Average Fuel Economy Standards for 2012-2016 (75 FR 25324, May 7, 

2010)

 

213 U.S. Energy Information Administration, Annual Energy Outlook (April 15, 2013)
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 Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for 

Medium- and Heavy-Duty Engines and Vehicles (76 FR 57106, 

September 15, 2011)

 2017 and Later Model Year Light-Duty Vehicle Greenhouse Gas 

Emissions and Corporate Average Fuel Economy Standards (77 FR 

62623, October 15, 2012)

The analysis also accounts for many other national rules and standards. In addition, the 

modeling accounts for state and local rules including California’s most recent Low 

Emission Vehicle (LEV III) program adopted in California and twelve other states (also 

referred to as Section 177 states),214 local fuel standards, Inspection/Maintenance 

programs, Stage II refueling controls, the National Low Emission Vehicle Program 

(NLEV), and the Section 177 states LEV and LEV II programs. See the Tier 3 emissions 

modeling TSD for more detail.

A summary of emission reductions projected to result from Tier 3, relative to the 

reference case, is shown in calendar years 2018 and 2030 for NOX, VOC, direct PM2.5, 

CO, SO2, and total air toxics in Table III-1. For many pollutants, the immediate 

reductions in 2018 are significant; for example, combined NOX and VOC emissions will 

be reduced by over 300,000 tons. By 2030, combined NOX and VOC emissions will be 

reduced by roughly 500,000 tons, one quarter of the onroad inventory. Many of the 

modeled air toxics will be significantly reduced as well, including benzene, 1,3-

butadiene, acetaldehyde, acrolein and ethanol (ranging from 10 to nearly 30 percent of 

the national onroad inventory by 2030). The relative reduction in overall emissions will 

continue to increase beyond 2030 as more of the fleet continues to turn over to Tier 3 

vehicles; for example, by 2050, when nearly all of the fleet will have turned over to 

vehicles meeting the fully phased-in Tier 3 standards, we estimate the Tier 3 program 

will reduce onroad emissions of NOX and VOC nearly 31 percent from the level of 

emissions projected without Tier 3 controls. 

Table III-1 Estimated Emission Reductions from the Tier 3 Standards 

(Annual U.S. Short Tons)

2018 2030

Tons % of 

Onroad 

Inventory

Tons % of 

Onroad 

Inventory

NOX 264,369 10% 328,509 25%

VOC 47,504 3% 167,591 16%

 

214 These states include Connecticut, Delaware, Maryland, Maine, Massachusetts, New Jersey, New York, 

Oregon, Pennsylvania, Rhode Island, Washington, and Vermont.
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CO 278,879 2% 3,458,041 24%

Direct PM2.5 130 0.1% 7,892 10%

Benzene 1,916 6% 4,762 26%

SO2 14,813 56% 12,399 56%

1,3-Butadiene 257 5% 677 29%

Formaldehyde 513 2% 1,277 10%

Acetaldehyde 600 3% 2,067 21%

Acrolein 40 3% 127 15%

Ethanol 2,704 2% 19,950 16%

Reductions for each pollutant are discussed in the following sections, focusing on 

the contribution of program elements to the total reductions summarized above. 

1. NOX

The Tier 3 sulfur standards will significantly reduce NOX emissions immediately

upon implementation of the program. As discussed above, recent research on the impact 

of sulfur on Tier 2 technology vehicles shows the potential for significant reductions in 

NOX emissions from the existing fleet of Tier 2 vehicles by lowering sulfur levels to 10 

ppm. Prior research shows that NOX emissions will also be expected to decrease from 

the fleet of older (pre-Tier 2) light-duty vehicles as well as heavy-duty gasoline 

vehicles,215 although to a lesser extent than for Tier 2 vehicles. 

Table III-2 shows the reduction in NOX emissions, in annual short tons, projected 

in calendar years 2018 and 2030. The reductions are split into those attributable to the 

introduction of low sulfur fuel in the pre-Tier 3 fleet (defined for this analysis as model 

years prior to 2017); and reductions attributable to vehicle standards enabled by low 

sulfur fuel (model year 2017 and later). As shown, upon implementation of the Tier 3 

sulfur standards, total onroad NOX emissions are projected to drop 10 percent. This is 

primarily due to large reductions from Tier 2 gasoline vehicles, which contribute about 

one-quarter of the NOX emissions from the on-road fleet in 2018. The relative reduction 

grows as cleaner vehicles turn over into the fleet. By 2030, we project that the reduction 

in overall onroad NOX inventory will be 25 percent.

Table III-2 Projected NOX Reductions from Tier 3 Program (Annual U.S. Tons)

2018 2030

Total reduction 264,369 328,509

Reduction from pre-Tier 3 

fleet due to sulfur standard

242,434 56,324

Reduction from Tier 3 fleet 21,934 272,185

 

215 Rao, V. (2001), Fuel Sulfur Effects on Exhaust Emissions: Recommendations for MOBILE6, EPA420-R-01-039
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due to vehicle and sulfur 

standards 

Percent reduction in 

onroad NOX emissions

10% 25%

2. VOC

Table III-3 shows the reduction in VOC emissions, in annual short tons, projected 

in calendar years 2018 and 2030 resulting from the Tier 3 standards. In 2018, as with 

NOX, we project reductions from the pre-Tier 3 fleet with the fuel standards. By 2030, 

the reduction in overall onroad VOC emissions will be 16 percent, the majority of this 

from the vehicles meeting the fully phased-in Tier 3 standards. The evaporative standards 

are projected to account for roughly one third of the overall vehicle program reduction in 

2030. 

Table III-3 Projected VOC Reductions from Tier 3 Program (Annual U.S. Tons)

2018 2030

Total reduction 47,504 167,591

Reduction from pre-Tier 3 

fleet due to sulfur standard

38,786 11,249

Reduction from Tier 3 fleet 

due to vehicle and sulfur 

standards 

8,718 156,343

Exhaust 43,009 105,253

Evaporative 4,495 62,339

Percent reduction in 

onroad VOC emissions

3% 16%

3. CO

Table III-4 shows the reductions for CO, broken down by pre- and post-Tier 3 in 

the manner described for NOX and VOC above. In contrast to NOx and VOC, the 

immediate CO reductions in the onroad fleet from sulfur control in 2018 are small, based 

on research showing that fuel sulfur level has a minimal impact on CO emissions from 

Tier 2 vehicles. The CO exhaust standards are projected to reduce onroad CO emissions 

by 24 percent in 2030. 

Table III-4 Projected CO Reductions from Tier 3 Program (Annual U.S. Tons)

2018 2030

Total reduction 278,879 3,458,041

Reduction from pre-Tier 3 

fleet due to sulfur standard

122,171 17,734

Reduction from Tier 3 fleet 

due to vehicle and sulfur 

156,708 3,440,307
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standards

Percent reduction in 

onroad CO emissions

2% 24%

4. Direct PM2.5

Reductions in direct emissions of PM2.5 are projected to result solely from the 

vehicle tailpipe standards, so meaningful reductions are realized mainly as the fleet turns 

over. By 2030, we project a reduction of about 7,900 tons annually, which represents 

approximately 10 percent of the onroad direct PM2.5 inventory. The relative reduction in 

onroad emissions is projected to grow to 28 percent in 2050, when nearly all of the fleet 

will have turned over to vehicles meeting the fully phased-in Tier 3 standards. 

Reductions in NOX and VOC emissions will also reduce secondary PM formation, which 

is quantified as part of the air quality analysis described in Section III.C. 

5. Air Toxics

Emissions of air toxics also will be reduced by the sulfur, exhaust and evaporative 

standards. Air toxics are generally a subset of compounds making up VOC, so the 

reduction trends tend to track the VOC reductions presented above, for most air toxics. 

Table III-5 presents reductions for certain key air toxics, and Table III-6 presents 

reductions for the sum of 71 different toxic compounds. 

Table III-5 Reductions for Certain Individual Compounds (Annual U.S. Tons)

Tons 

Reduced in 

2018

% Reduction 

in Onroad 

Emissions

Tons Reduced 

in 2030

% Reduction in 

Onroad 

Emissions

Benzene 1,916 6% 4,762 26%

Acetaldehyde 600 3% 2,067 21%

Formaldehyde 513 2% 1,277 10%

1,3-Butadiene 257 5% 677 29%

Acrolein 40 3% 127 15%

Naphthalene 99 3% 269 15%

Ethanol 2,704 2% 19,950 16%

The totals shown in Table III-6 represent the sum of 71 species including the 

toxics in Table III-5, 15 polycyclic aromatic hydrocarbon (PAH) compounds in gas and 

particle phase, and additional gaseous compounds such as toluene, xylenes, styrene, 

hexane, 2,2,4-trimethylpentane, n-hexane, and propionaldehyde (see Appendix 7A of the 

RIA). As shown, in 2030, the overall onroad inventory of total toxics will be reduced by

15 percent, with nearly one half of the vehicle program reductions coming from the 

evaporative standards. 
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Table III-6 Reductions in Total Mobile Source Air Toxics (Annual U.S. Tons)

2018 2030

Total reduction 15,583 64,558

Reduction from pre-Tier 3 

fleet due to sulfur standard

11,981 3,517

Reduction from Tier 3 fleet 

due to vehicle and sulfur 

standards

3,602 61,041

Exhaust 13,340 34,595

Evaporative 2,243 29,963

Percent reduction in 

onroad toxics emissions

3% 15%

6. SO2

SO2 emissions from mobile sources are a direct function of sulfur in the fuel, and 

reducing sulfur in gasoline will result in immediate reductions in SO2 from the on and 

off-road fleet. The reductions, shown in Table III-7, are a function of the sulfur level and 

fuel consumption. This is reflected in the relative contribution of on-road vehicles and 

off-road equipment, where off-road gasoline consumption accounts for approximately 5 

percent of overall gasoline use.216

Table III-7 Projected SO2 Reductions from Tier 3 Program (Annual U.S. Tons)

2018 2030

Total reduction 15,565 13,261

Reduction from onroad 

vehicles due to sulfur 

standard

14,813 12,399

Reduction from off-road 

equipment due to sulfur 

standard

752 862

Percent reduction in 

onroad SO2 emissions

56% 56%

7. Greenhouse Gases

Reductions in nitrous oxide (N2O) emissions and methane (CH4) emissions, both 

potent greenhouse gas emissions, are projected for gasoline cars and trucks as a result of 

the sulfur and tailpipe standards. A study conducted by the University of CaliforniaRiverside found a 29 percent reduction in N2O emissions over the FTP when sulfur was 

 

216 U.S. Energy Information Administration, Annual Energy Outlook 2013 (April 15, 2013)
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reduced from 30 to 5 ppm,217 while EPA research described in Section IV.A.6 on sulfur 

effects found a 26 percent reduction in CH4 emissions when sulfur was reduced from 28 

to 5 ppm.218 

Several studies have established correlations between reductions in tailpipe NOX

emissions and reductions in N2O from gasoline cars and trucks,219,220,221,222 as well as 

correlations between reductions in tailpipe HC emissions and reductions in CH4.

223,224

 

Studies by Winer, et al (2005) and Behrentz et al (2004) reported N2O: NOX ratios of 

0.06 and 0.095, respectively, and supported the application of N2O: NOX ratios to NOX

emissions as a reasonable method for estimating N2O emission inventories. CARB has 

also used N2O: NOX ratio to develop the N2O emissions inventories for the LEV III 

program, based on a regression analysis suggesting N2O: NOX ratio of 0.04, on 

average.225 

As detailed in Chapter 7.3 of the RIA, the N2O reductions are estimated by 

employing two different methodologies, resulting in a range of reductions. The first 

method applies the relationship between N2O and NOX from a regression model226 to 

NOX inventories from both Tier 3 and pre-Tier 3 vehicles. The second method applies 

the regression of N2O and NOX only to Tier 3 vehicles and uses the UC Riverside sulfur 

results to estimate the N2O reductions from pre-Tier 3 vehicles. Using a 100-year global 

warming potential of 298 for N2O according to the 2007 IPCC AR4,227 the estimated N2O 

 

217 Huai, et al. (2004), Estimates of the emission rates of nitrous oxide from light-duty vehicles using 

different chassis dynamometer test cycles, Atmospheric Environment 6621-6629 

218 The Effects of Ultra-Low Sulfur Gasoline on Emissions from Tier 2 Vehicles in the In-Use Fleet, EPA420-R-14-002,

219 Michaels, H. (1998) Emissions of Nitrous Oxide from Highway Mobile Sources, U.S. EPA EPA420-R98-009 

220 Behrentz, et al. (2004), Measurements of nitrous oxide emissions from light-duty motor vehicles: a pilot 

study, Atmospheric Environment 4291-4303 

221 Meffert, et. al (2000) Analysis of Nitrous Oxide Emissions from Light Duty Passenger Cars, SAE 2000-

01-1952

222 Winer, et al. (2005) Estimates of Nitrous Oxide Emissions and the Effects of Catalyst Composition and 

Aging, State of California Air Resources Board 02-313

223 Meszler, D. (2004), Light Duty Vehicle Methane and Nitrous Oxide Emissions: Greenhouse Gas 

Impacts, Study for Northeast States Center for a Clean Air Future

224 Graham, L., Greenhouse Gas Emissions from 1997-2005 Model Year Light Duty Vehicles, 

Environment Canada ERMD Report #04-44 

225 LEV III Moblie Source Emissions Inventory Technical Support Document – Appendix T, January 2012, 

last accessed on 01/15/14 at the following URL: 

http://www.arb.ca.gov/regact/2012/leviiighg2012/levappt.pdf

226 U.S. EPA, 2014, Memorandum to Docket: Regression Analysis of Nitrous Oxide and Oxides of 

Nitrogen from Motor Vehicles.

227 The global warming potentials (GWP) used in this rule are consistent with the 100-year time frame 

values in the 2007 Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4). 

At this time, the 1996 IPCC Second Assessment Report (SAR) 100-year GWP values are used in the 

official U.S. greenhouse gas inventory submission to the United Nations Framework Convention on 
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reduction is 2.2 million metric tons of carbon dioxide equivalent (MMTCO2e) in 2018, 

growing to the range between 3.8 to 4.0 MMTCO2e in 2030. For 2018, there was an 

agreement between the two methodologies described above, resulting in a single 

estimate. MOVES can be used to directly estimate CH4 reductions from the sulfur and 

vehicle standards, estimating an additional 0.1 MMTCO2e reduction in 2018, growing to 

0.3 MMTCO2e in 2030. The total GHG reduction from the Tier 3 rule is 2.3 MMTCO2e 

in 2018, and between 4.1 and 4.3 MMTCO2e in 2030. 

These reductions will be partially offset by CO2 emissions associated with higher 

energy use required in the process of removing sulfur within the refinery. As an 

extension of our refinery-by-refinery cost modeling described in Section VII.B., we 

calculated the CO2 emission impacts of Tier 3 gasoline sulfur control. We estimated 

refinery-specific changes in process energy and then applied emission factors that 

correspond to those changes, on a refinery-by-refinery basis. As described in Chapter 4.5 

of the RIA, the results showed an increase of up to 1.9 MMTCO2e in 2018 and 1.6 

MMTCO2e in 2030 for all U.S. refineries complying with the lower sulfur standards 

assuming that the sulfur standards are fully phased-in. In 2018, the combined impact of 

CH4 and N2O emission reductions from the vehicles and CO2 emission increases from the 

refineries shows a slight net decrease on a CO2 equivalent basis. While still small, this 

net decrease grows to a range between 2.5 to 2.7 MMTCO2e by 2030. 

We do not expect the Tier 3 vehicle standards to result in any discernible changes 

in vehicle CO2 emissions or fuel economy. Emissions of the pollutants that are controlled 

by the Tier 3 program – NMOG, NOX, and PM – are not a function of the amount of fuel 

consumed, since manufacturers need to design their catalytic emission control systems to

reduce these emissions regardless of their engine-out levels. 

C. How Will Air Pollution Be Reduced? 

Reductions in emissions of NOX, VOC, PM2.5 and air toxics expected as a result 

of the Tier 3 standards are projected to lead to significant improvements in air quality. 

The air quality modeling predicts significant improvements in ozone concentrations due 

to the Tier 3 standards. Ambient PM2.5 and NO2 concentrations are also expected to 

improve as a result of the Tier 3 program. Decreases in ambient concentrations of air 

toxics are projected with the Tier 3 standards, including notable nationwide reductions in 

benzene concentrations. Our air quality modeling also predicts improvements in 

visibility and sulfur deposition, as well as substantial decreases in nitrogen deposition as 

a result of the Tier 3 standards. The results of our air quality modeling of the impacts of 

the Tier 3 rule are summarized in the following section. 

 

Climate Change (per the reporting requirements under that international convention, which were last 

updated in 2006). N2O has a 100-year GWP of 298 and CH4 has a 100-year GWP of 25 according to the

2007 IPCC AR4.
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1. Ozone

The air quality modeling done for this action projects that in 2018, with all current 

and required controls in effect but excluding the emissions changes expected to occur as a 

result of the Tier 3 standards or any other additional controls, at least 19 counties, with a 

projected population of over 37 million people, would have projected design values 

above the level of the 2008 8-hour ozone standard of 75 ppb. In 2030 the modeling 

projects that in the absence of Tier 3 standards or any other additional controls there will 

be 6 counties with a population of over 19 million people with projected design values 

above the level of the 2008 8-hour ozone standard of 75 ppb. An additional 37 million 

people will be living in the 43 counties that will be close to (within 10 percent of) the 

level of the ozone standard. 

Air quality modeling indicates that this action will meaningfully decrease ozone 

design value concentrations in many areas of the country, including those that are 

projected to be exceeding, or close to exceeding, the ozone standard. In 2018, the 

majority of the design value decreases are between 0.5 and 1.0 ppb. In 2030, the Tier 3 

rule will result in larger decreases in ozone design values, with the majority of counties 

projecting decreases of between 0.5 and 1.0 ppb, and over 250 more counties with 

decreases greater than 1.0 ppb. Since the Tier 3 standards go into effect during the period 

when some areas are still working to attain the ozone NAAQS, the projected air quality 

changes will help state and local agencies in their effort to attain and maintain the ozone 

standard. 

2. Particulate Matter

The air quality modeling conducted for this action projects that in 2018, with all 

current controls in effect but excluding the emissions changes expected to occur as a 

result of Tier 3 standards or any other additional controls, at least 14 counties, with a 

projected population of over 20 million people, would have projected design values 

above the level of the annual standard of 12 μg/m3 and at least 24 counties, with a 

projected population of over 18 million people, would have projected design values 

above the level of the 24-hour standard of 35 μg/m3. In 2030, the modeling projects that 

in the absence of Tier 3 standards or any other additional controls there will be 13 

counties, with a projected population of over 21 million people, with projected design 

values above the level of the annual standard of 12 μg/m3 and 18 counties, with a 

projected population of over 12 million people, with projected design values above the 

level of the 24-hour standard of 35 μg/m3. Since the Tier 3 standards go into effect 

during the period when some areas are still working to attain the 2006 and 2012 PM2.5

NAAQS, the projected air quality changes will be useful to state and local agencies in 

their effort to attain and maintain the PM2.5 standards. 

The Tier 3 standards will reduce 24-hour and annual PM2.5 design values due to 

projected tailpipe reductions in primary PM2.5, SO2, NOX and VOCs from reductions in 

fuel sulfur and engine controls. In 2018 the standards will have a small impact on annual 
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PM2.5 design values in the majority of modeled counties. However, in over 200 counties 

annual PM2.5 design values are projected to decrease by greater than 0.01 μg/m3. In 2030 

annual PM2.5 design values in the majority of modeled counties will decrease by between 

0.01 and 0.05 μg/m3 and in over 140 additional counties design values are projected to 

decrease by greater than 0.05 μg/m3. In addition, in 2018 24-hour PM2.5 design values in 

over 200 counties are projected to decrease by between 0.05 and 0.15 μg/m3 and in 2030 

24-hour PM2.5 design values in over 180 counties decrease by at least 0.15 μg/m3. 

3. Nitrogen Dioxide

Although our modeling indicates that by 2030 the majority of the country will 

experience decreases of less than 0.1 ppb in their annual NO2 concentrations due to this 

rule, annual NO2 concentrations are projected to decrease by more than 0.3 ppb in most 

urban areas. These emissions reductions would also likely decrease 1-hour NO2

concentrations and help any potential nonattainment areas to attain and maintain the 

standard. Additional information on the emissions reductions that are projected with this 

rule is available in Section 7.2.1 of the RIA. 

4. Air Toxics

Our modeling indicates that the impacts of final Tier 3 standards include notable 

nationwide reductions in benzene and generally small decreases in ambient 

concentrations of other air toxics, mainly in urban areas. Although reductions are greater 

in 2030 (when 70 percent of the miles travelled are from vehicles that meet the fully

phased-in Tier 3 standards) than in 2017 (the first year of the final program), our 

modeling projects there will be small immediate reductions in ambient concentrations of 

air toxics due to the Tier 3 sulfur controls. Furthermore, the full reduction of the vehicle 

program will be realized after 2030, when the fleet has fully turned over to vehicles 

meeting the fully phased-in Tier 3 standards. Air toxics pollutants dominated by primary

emissions (or a decay product of a directly emitted pollutant), such as benzene, are 

impacted more than air toxics that primarily result from photochemical transformation. 

Specifically, in 2030, our modeling projects that the Tier 3 rule will decrease 

ambient benzene concentrations across much of the country on the order of 1 to 5 

percent, with reductions ranging from 10 to 25 percent in some urban areas. Our 

modeling also shows reductions of 1,3-butadiene and acrolein concentrations in 2030 

ranging between 1 and 25 percent and 1 and 10 percent respectively, with 1,3-butadiene 

decreases of at least 0.005 μg/m3 in urban areas. These toxics are national risk drivers 

and the reductions in ambient concentrations from this rule will result in reductions in 

risks from cancer and noncancer health effects. In some parts of the country (mainly

urban areas), ethanol and formaldehyde concentrations are projected to decrease on the 

order of 1 to 10 percent and 1 to 2.5 percent respectively in 2030 as a result of the Tier 3 

rule. Decreases in ethanol concentrations are expected due to reductions in VOC as a 

result of the Tier 3 standards. Changes in ambient acetaldehyde concentrations are 

generally less than 1 percent across the U.S., although the Tier 3 rule may decrease 
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acetaldehyde concentrations in some urban areas by 1 to 2.5 percent in 2030. Changes in 

ambient naphthalene concentrations are generally between 1 and 10 percent in 2030 with 

absolute decreases of up to 0.005 μg/m3. 

Although the reductions in ambient air toxics concentrations expected from the 

Tier 3 standards are generally small, they are projected to benefit the majority of the U.S. 

population. As shown in Table III-8, over 75 percent of the total U.S. population is 

projected to experience a decrease in ambient benzene and 1,3-butadiene concentrations 

of at least 1 percent. Over 60 percent of the U.S population is projected to experience at 

least a 1 percent decrease in ambient ethanol and acrolein concentrations, and over 35 

percent would experience a similar decrease in ambient formaldehyde concentrations 

with the Tier 3 standards. 

Table III-8 Percent of Total Population Experiencing Changes in Annual Ambient 

Concentrations of Toxic Pollutants in 2030 as a Result of the Tier 3 Standards

Percent Change Benzene Acrolein 1,3-Butadiene Formaldehyde Ethanol Acetaldehyde Naphthalene

≤ -50

> -50 to ≤ -25

> -25 to ≤ -10 2.29% 0.75% 19.07% 10.74%

> -10 to ≤ -5 20.63% 12.72% 27.29% 5.39% 31.56%

> -5 to ≤ -2.5 27.50% 25.17% 15.37% 0.60% 24.08% 20.58%

> -2.5 to ≤ -1 28.60% 24.62% 18.33% 35.34% 34.10% 11.77% 14.98%

> -1 to < 1 20.97% 36.74% 19.93% 64.06% 36.43% 88.23% 22.14%

≥ 1 to < 2.5

≥ 2.5 to < 5

≥ 5 to < 10

≥ 10 to < 25

≥ 25 to < 50

≥ 50 

In addition, as described in Section 7.2.4.4.2 of the RIA, our modeling projects 

that acrolein concentrations would decrease to levels below the inhalation reference 

concentration for acrolein (0.02 μg/m3) for over 5 million people in 2030, meaning that as 

a result of the Tier 3 standards, 5 million fewer Americans will be exposed to ambient 

levels of acrolein high enough to present a potential for adverse health effects. 

5. Visibility

Air quality modeling conducted for this final action was used to project visibility

conditions in 137 mandatory class I federal areas across the U.S. The results show that in 
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2030 all the modeled areas will continue to have annual average deciview levels above 

background and the Tier 3 rule will improve visibility in all these areas.228 The average 

visibility at all modeled mandatory class I federal areas on the 20 percent worst days is 

projected to improve by 0.02 deciviews, or 0.16 percent, in 2030. Section 7.2.5.5 of the 

RIA contains more detail on the visibility portion of the air quality modeling.

6. Nitrogen and Sulfur Deposition

Our air quality modeling projects substantial decreases in nitrogen deposition as a 

result of the Tier 3 standards. The standards will result in annual percent decreases of 

greater than 2.5 percent in most major urban areas and greater than 5 percent in a few 

areas. In addition, smaller decreases, in the 1 to 2.5 percent range, will occur over much 

of the rest of the country. The impacts of the Tier 3 standards on sulfur deposition are 

smaller, ranging from no change to decreases of over 2.5 percent in some areas. For 

maps of 2030 deposition impacts and additional information on these impacts see Section 

7.2.5.6 of the RIA. 

7. Environmental Justice

Environmental justice (EJ) is a principle asserting that all people deserve fair 

treatment and meaningful involvement with respect to environmental laws, regulations, 

and policies. EPA seeks to provide the same degree of protection from environmental 

health hazards for all people. As referenced below, numerous studies have found that 

some environmental hazards are more prevalent in areas with high population fractions 

of racial/ethnic minorities and people with low socioeconomic status (SES), as would be 

expected on the basis of those areas’ share of the general population.

As discussed in Section II of this document, concentrations of many air pollutants 

are elevated near high-traffic roadways. If minority populations and low-income 

populations disproportionately live near such roads, then an issue of EJ may be present. 

Such disparities may be due to multiple factors.229

People with low SES often live in neighborhoods with multiple stressors and 

health risk factors, including reduced health insurance coverage rates, higher smoking 

and drug use rates, limited access to fresh food, visible neighborhood violence, and 

 

228 The level of visibility impairment in an area is based on the light-extinction coefficient and a unitless 

visibility index, called a “deciview,” which is used in the valuation of visibility. The deciview metric 

provides a scale for perceived visual changes over the entire range of conditions, from clear to hazy. Under 

many scenic conditions, the average person can generally perceive a change of one deciview. The higher 

the deciview value, the worse the visibility. Thus, an improvement in visibility is a decrease in deciview 

value.

229 Depro, B.; Timmins, C. (2008) Mobility and environmental equity: do housing choices determine 

exposure to air pollution? North Caroline State University Center for Environmental and Resource 

Economic Policy
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elevated rates of obesity and some diseases such as asthma, diabetes, and ischemic heart 

disease. Although questions remain, several studies find stronger associations between 

air pollution and health in locations with such chronic neighborhood stress, suggesting 

that populations in these areas may be more susceptible to the effects of air 

pollution.230,231,232,233 Household-level stressors such as parental smoking and 

relationship stress also may increase susceptibility to the adverse effects of air 

pollution.234,235

To address the existing conditions in areas near major roadways, in comparison 

with other locations, we reviewed existing scholarly literature examining the topic, and 

conducted our own evaluation of two national datasets: the U.S. Census Bureau’s 

American Housing Survey for calendar year 2009 and the U.S. Department of 

Education’s database of school locations.

Existing publications that address EJ issues generally report that populations 

living near major roadways (and other types of transportation infrastructure) tend to be 

composed of larger fractions of nonwhite residents. People living in neighborhoods near 

such sources of air pollution also tend to be lower in income than people living 

elsewhere. Numerous studies evaluating the demographics and socioeconomic status of 

populations or schools near roadways have found that they include a greater percentage 

of minority residents, as well as lower SES (indicated by variables such as median 

household income). Locations in these studies include Los Angeles, CA; Seattle, WA; 

Wayne County, MI; Orange County, FL; and the State of California 236,237,238,239,240,241 

 

230 Clougherty, J.E.; Kubzansky, L.D. (2009) A framework for examining social stress and susceptibility to 

air pollution in respiratory health. Environ Health Perspect 117: 1351-1358. Doi:10.1289/ehp.0900612 

[Online at http://dx.doi.org]

231 Clougherty, J.E.; Levy, J.I.; Kubzansky, L.D.; Ryan, P.B.; Franco Suglia, S.; Jacobson Canner, M.; 

Wright, R.J. (2007) Synergistic effects of traffic-related air pollution and exposure to violence on urban 

asthma etiology. Environ Health Perspect 115: 1140-1146. doi:10.1289/ehp.9863 [Online at 

http://dx.doi.org]

232 Finkelstein, M.M.; Jerrett, M.; DeLuca, P.; Finkelstein, N.; Verma, D.K.; Chapman, K.; Sears, M.R. 

(2003) Relation between income, air pollution and mortality: a cohort study. Canadian Med Assn J 169: 

397-402.

233 Shankardass, K.; McConnell, R.; Jerrett, M.; Milam, J.; Richardson, J.; Berhane, K. (2009) Parental 

stress increases the effect of traffic-related air pollution on childhood asthma incidence. Proc Natl Acad 

Sci 106: 12406-12411. doi:10.1073/pnas.0812910106 [Online at http://dx.doi.org]

234 Lewis, A.S.; Sax, S.N.; Wason, S.C.; Campleman, S.L (2011) Non-chemical stressors and cumulative 

risk assessment: an overview of current initiatives and potential air pollutant interactions. Int J Environ 

Res Public Health 8: 2020-2073. Doi:10.3390/ijerph8062020 [Online at http://dx.doi.org]

235 Rosa, M.J.; Jung, K.H.; Perzanowski, M.S.; Kelvin, E.A.; Darling, K.W.; Camann, D.E.; Chillrud, S.N.; 

Whyatt, R.M.; Kinney, P.L.; Perera, F.P.; Miller, R.L (2010) Prenatal exposure to polycyclic aromatic 

hydrocarbons, environmental tobacco smoke and asthma. Respir Med (In press). 

doi:10.1016/j.rmed.2010.11.022 [Online at http://dx.doi.org]

236 Marshall, J.D. (2008) Environmental inequality: air pollution exposures in California’s South Coast Air 

Basin.
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More recently, three publications report nationwide analyses that compare the 

demographic patterns of people who do or do not live near major roadways.242,243,244 All 

three of these studies found that people living near major roadways are more likely to be 

minorities or low in SES. They also found that the outcomes of their analyses varied 

between regions within the U.S. However, only one such study looked at whether such 

conclusions were confounded by living in a location with higher population density and 

how demographics differ between locations nationwide. In general, it found that higher 

density areas have higher proportions of low income and minority residents.

We analyzed two national databases that allowed us to evaluate whether homes 

and schools were located near a major road. One database, the American Housing 

Survey (AHS), includes descriptive statistics of over 70,000 housing units across the 

nation. The study is conducted every two years by the U.S. Census Bureau. We 

analyzed data from the 2009 AHS. The second database we analyzed was the U.S. 

Department of Education’s Common Core of Data, which includes enrollment and 

location information for schools across the U.S.

In analyzing the 2009 AHS, we focused on whether or not a housing unit was 

located within 300 feet of “4-or-more lane highway, railroad, or airport.”245 We 

analyzed whether there were differences between houses and householders in such 

locations and those not in them.246 We included other variables, such as land use 

 

237 Su, J.G.; Larson, T.; Gould, T.; Cohen, M.; Buzzelli, M. (2010) Transboundary air pollution and 

environmental justice: Vancouver and Seattle compared. GeoJournal 57: 595-608. doi:10.1007/s10708-

009-9269-6 [Online at http://dx.doi.org]

238 Chakraborty, J.; Zandbergen, P.A. (2007) Children at risk: measuring racial/ethnic disparities in 

potential exposure to air pollution at school and home. J Epidemiol Community Health 61: 1074-1079. 

doi: 10.1136/jech.2006.054130 [Online at http://dx.doi.org]

239 Green, R.S.; Smorodinsky, S.; Kim, J.J.; McLaughlin, R.; Ostro, B. (2003) Proximity of California 

public schools to busy roads. Environ Health Perspect 112: 61-66. doi:10.1289/ehp.6566 

[http://dx.doi.org]

240 Wu, Y; Batterman, S.A. (2006) Proximity of schools in Detroit, Michigan to automobile and truck 

traffic. J Exposure Sci & Environ Epidemiol. doi:10.1038/sj.jes.7500484 [Online at http://dx.doi.org]

241 Su, J.G.; Jerrett, M.; de Nazelle, A.; Wolch, J. (2011) Does exposure to air pollution in urban parks have 

socioeconomic, racial, or ethnic gradients? Environ Res 111: 319-328.

242 Rowangould, G.M. (2013) A census of the US near-roadway population: public health and 

environmental justice considerations. Transportation Research Part D; 59-67.

243 Tian, N.; Xue, J.; Barzyk. T.M. (2013) Evaluating socioeconomic and racial differences in traffic-related 

metrics in the United States using a GIS approach. J Exposure Sci Environ Epidemiol 23: 215-222.

244 Boehmer, T.K.; Foster, S.L.; Henry, J.R.; Woghiren-Akinnifesi, E.L.; Yip, F.Y. (2013) Residential 

proximity to major highways – United States, 2010. Morbidity and Mortality Weekly Report 62(3): 46-50. 

245 This variable primarily represents roadway proximity. According to the Central Intelligence Agency’s 

World Factbook, in 2010, the United States had 6,506,204 km or roadways, 224,792 km of railways, and 

15,079 airports. Highways thus represent the overwhelming majority of transportation facilities described 

by this factor in the AHS.

246 Bailey, C. (2011) Demographic and Social Patterns in Housing Units Near Large Highways and other 

Transportation Sources. Memorandum to docket.
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category, region of country, and housing type. We found that homes with a nonwhite 

householder were 22-34 percent more likely to be located within 300 feet of these large 

transportation facilities, while homes with a Hispanic householder were 17-33 percent 

more likely. Households near large transportation facilities were, on average, lower in 

income and educational attainment, more likely to be a rental property and located in an 

urban area.

In examining schools near major roadways, we examined the Common Core of 

Data (CCD) from the U.S. Department of Education, which includes information on all 

public elementary and secondary schools and school districts nationwide.247 To 

determine school proximities to major roadways, we used a geographic information 

system (GIS) to map each school and roadways based on the U.S. Census’s TIGER 

roadway file.248 We found that minority students were overrepresented at schools within 

200 meters of the largest roadways, and that schools within 200 meters of the largest 

roadways also had higher than expected numbers of students eligible for free or reducedprice lunches. For example, Black students represent 21.57 percent of students at 

schools located within 200 meters of a primary road, whereas Black students represent 

16.62 percent of students in all U.S. schools. Hispanic students represent 30.13 percent 

of students at schools located within 200 meters of a primary road, whereas Hispanic 

students represent 21.93 percent of students in all U.S. schools.

Overall, there is substantial evidence that people who live or attend school near 

major roadways are more likely to be of a minority race, Hispanic ethnicity, and/or low 

SES. The emission reductions from this rule are projected to result in widespread air 

quality improvements, but the impact on pollution levels in close proximity to roadways 

is expected to be most direct. Thus, this rule is likely to help in mitigating the disparity

in racial, ethnic, and economically-based exposures. 

IV. Vehicle Emissions Program

In the 14 years since EPA finalized the Tier 2 Vehicle Program, manufacturers of 

light-duty vehicles have continued to develop a wide range of improved technologies 

capable of reducing emissions, especially exhaust hydrocarbons, nitrogen oxides (NOX), 

and particulate matter (PM), and evaporative hydrocarbons. The California LEV II 

program has been instrumental in the auto industry’s continuous technology

improvements by requiring year after year reductions in fleet average exhaust 

hydrocarbon levels. In addition, California set performance standards that have resulted 

in the introduction of advanced exhaust and evaporative emission controls in partial zero 

 

247 http://nces.ed.gov/ccd/

248 Pedde, M.; Bailey, C. (2011) Identification of Schools within 200 Meters of U.S. Primary and 

Secondary Roads. Memorandum to the docket.
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emission vehicles (PZEVs). Overall, this progress in vehicle technology has made it 

possible for manufacturers to achieve emission reductions with a number of today’s 

vehicles that go well beyond the requirements of the Tier 2 program. 

Extensive data from existing Tier 2 (and California LEV II) vehicles presented in 

the NPRM and received since the proposal have demonstrated the potential for further 

significant reductions. For exhaust emissions, these opportunities include addressing: 

emissions produced at start-up; emissions under high-speed, high-load conditions; the 

effects of sulfur in gasoline; the effects of increased oil consumption; and the effects of 

age on vehicles and control systems. In addition, technologies now exist that have 

inherently low evaporative emission characteristics and demonstrate improved in-use 

durability. Based on this body of data, we are adopting more stringent standards 

designed to reduce emissions, primarily exhaust non-methane organic gases (NMOG), 

NOX, and PM and evaporative hydrocarbon emissions from new vehicles. As discussed 

in detail below and in the final RIA, we have concluded that, in conjunction with the 

reductions in fuel sulfur also required in this action, the new vehicle emissions standards 

are feasible, accounting for costs, across the fleet in the timeframe of the program. We 

believe that simultaneous reductions in fuel sulfur will be a key factor in enabling the 

entire fleet of vehicles subject to Tier 3 to meet the new emission standards in-use, 

throughout the life of the vehicles (see Section IV.A.6 below).

We received a large number and wide range of comments on the proposed vehicle 

emission program, and we have carefully considered all of them. (The Summary and 

Analysis of Comments document addresses the comments received; it is located in the 

docket for this rulemaking and also on EPA’s website at www.epa.gov/otaq/tier3.htm.) 

With very few exceptions, we are finalizing the Tier 3 vehicle emission program as 

proposed, including the levels of the new emission standards and the phase-in schedules. 

In several cases, as discussed in detail below, the comments and/or newer technical 

information have resulted in adjustments to the proposed program, including when the 

requirements begin, what fuel is used for vehicle compliance testing, and what the PM 

standard level is for testing under aggressive driving conditions. The final Tier 3 vehicle 

provisions, like the proposal, also harmonize closely with California’s LEV III program. 

This section describes in detail the program for reducing tailpipe and evaporative 

emissions from light-duty vehicles (LDVs, or passenger cars), light-duty trucks (LDT1s, 

2s, 3s, and 4s), Medium-Duty Passenger Vehicles (MDPVs), and certain heavy-duty 

vehicles (HDVs). Sections IV.A and IV.B discuss the tailpipe emission standards and 

time lines, and other provisions for new LDVs, LDTs, and MDPVs and for new heavyduty vehicles up to 14,000 lbs Gross Vehicle Weight Rating (GVWR). Section IV.C 

presents the new Tier 3 evaporative emissions standards and program and Section IV.D

describes the new evaporative emissions leak test. Section IV.E presents improvements 

to the existing Onboard Diagnostics (OBD) provisions. In Section IV.F, we describe new 

provisions to update our federal certification fuel to better match today’s in-use fuel. We 

also discuss in this section the compliance flexibilities for small auto manufacturing 
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companies and small-volume manufacturers (IV.G) as well as new testing and test 

procedure provisions and other compliance provisions (IV.H).

A. Tier 3 Tailpipe Emission Standards for Light-Duty Vehicles, Light-Duty 

Trucks, and Medium-Duty Passenger Vehicles

1. How the Tier 3 Program is Harmonized with the California LEV III Program

In describing the Tier 3 program for light- and heavy-duty vehicles in this 

preamble, we discuss how the provisions are consistent with the California Air Resources 

Board (CARB) LEV III program.249 During the development of the proposed rule and in 

their comments, auto manufacturers stressed to us the importance of their being able to 

design and produce a single fleet of vehicles for all 50 states that simultaneously

complies with requirements under the Tier 3 program and the LEV III program, as well 

as greenhouse gas/CAFE requirements they are facing in the same timeframe. To the 

extent that the federal and California programs are consistent, special versions of vehicles 

with different emission control hardware and calibrations for different geographic areas 

will be unnecessary. This will allow manufacturers to avoid the additional costs of 

parallel design, development, calibration, and manufacturing. Consistency among 

programs also eliminates the need to supply aftermarket parts for repair of multiple 

versions of a vehicle. We believe that the most effective and efficient national program 

will result from close coordination between CARB LEV III and federal Tier 3 program 

elements and their implementation. 

To that end, we worked closely with CARB and the vehicle manufacturers, the 

latter both individually and through their trade associations, to align the two programs. 

The Tier 3 program is identical to LEV III in most major respects for light-duty vehicles 

(and heavy-duty vehicles, as described in sections below). The levels and the timing of 

the declining fleet-average NMOG+NOX standards are identical to those in LEV III. The 

Tier 3 emissions bins to which manufacturers will certify individual vehicle models in 

order to comply with the fleet-average standards, are also identical to those in LEV III. 

Similarly, the light-duty Tier 3 FTP PM standards and percent phase-in match those for 

LEV III through MY 2024. 

We note there are a few light-duty Tier 3 and LEV III provisions that are 

different, for reasons discussed below. For example, the LEV III program and the Tier 3 

program have different light-duty PM requirements late in the program (i.e., after MY 

2024 (IV.A.3.b.)), and the two programs have different final NMOG+NOX standards for 

small volume manufacturers (IV.G.1). As also discussed below, we are finalizing a 

 

249 See California Low-Emission Vehicles (LEV) & GHG 2012 regulations adopted by the State of 

California Air Resources Board, March 22, 2012, Resolution 12-21 incorporating by reference Resolution 

12-11, which was adopted January 26, 2012. Available at 

http://www.arb.ca.gov/regact/2012/leviiighg2012/leviiighg2012.htm (last accessed December 2, 2013).
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revised SFTP (US06) PM standard, and CARB has commented that it plans to take 

similar action in near future. CARB also indicated in their comments that they intend to 

consider several additional actions to further align several minor aspects of LEV III with 

the Tier 3 program once Tier 3 is finalized. 

Beyond the provisions mentioned above, the differences between the programs 

are not major and most will exist only in the transitional years of the Tier 3 program. 

These additional differences result from the fact that the LEV III requirements begin 

slightly earlier and that a limited phase-in of some provisions is necessary for a smooth 

transition to overall aligned programs. These temporary differences include the process 

for how early compliance credits are generated and used (e.g., Section IV.A.7.a); how 

quickly manufacturers will need to move toward certifying all of their vehicle models to 

longer useful-life values (e.g., Section IV.A.7.c) and on the new test fuel (e.g., Section 

IV.A.7.d); and transitional emissions bins to facilitate the transition from Tier 2 to Tier 3 

(Section IV.A.7.n). 

2. Summary of the Tier 3 FTP and SFTP Tailpipe Standards

a. Major Comments on and Significant Changes to the Proposal

As mentioned above, we are finalizing most aspects of the comprehensive Tier 3 

vehicle program as we proposed them. The levels of the FTP and SFTP standards for the 

key tailpipe pollutants of concern -- the sum of NMOG and NOX emissions, expressed as 

NMOG+NOX, and PM -- are the same as proposed (except for the numerically lower 

final PM SFTP (US06) standard, as discussed below). In addition, the timing of the 

requirements remains the same as in the NPRM, starting with MY2017 and MY2018 and 

phasing in according to the same declining fleet-average schedule for the NMOG+NOX

standards and the same percent-of-sales phase-in schedule for the PM standards. We 

continue to believe that these elements form a robust framework for the Tier 3 vehicle 

program and closely harmonize with the respective elements of California’s LEV III 

program.

There are several important provisions of the light-duty Tier 3 program that we 

have revised from the proposal, based on further consideration and information that we 

received from commenters. We discuss each of these in detail later in this section and 

summarize them here. 

 As described below in Section IV.A.2.c, each of the four primary Tier 3 

emission standards has an associated alternative phase-in option for heavier 

light-duty vehicles that a manufacturer can choose if it prefers a later start date 

(to provide 4 years of lead time) and a stable standard.250 We proposed that a 

 

250 In this preamble, “heavier light-duty vehicles” refers to LDVs and LDTs greater than 6,000 lbs GVWR 

and MDPVs, and “lighter light-duty vehicles” refers to LDVs and LDTs up to 6,000 lbs GVWR.
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manufacturer choosing these options be required to apply the alternative 

phase-in schedule to its entire light-duty fleet. In response to comments from 

automakers that this restriction would be unnecessarily burdensome, we 

reconsidered this provision. For the reasons discussed below, we are allowing 

a manufacturer to apply the alternative phase-in schedules to only their 

heavier light-duty vehicles, instead of their entire light-duty fleet. However, 

manufacturers have largely indicated that they plan on adopting the primary

program which is harmonized with LEV III.

 This Tier 3 rule provides an opportunity for EPA to reassess the degree to 

which the gasoline used for vehicle emissions testing and certification reflects 

in-use gasoline around the country. In the case of ethanol content, we 

proposed that the emissions test fuel contain 15 percent ethanol (E15), 

anticipating a significant shift to higher ethanol content in use in the near 

future. For several reasons described below (Section IV.F.1), this shift in inuse fuel is not materializing as quickly as expected, and E10 continues to be 

almost universal today. We received a near consensus among comments from 

stakeholders that E10 test fuel is more appropriate. We agree that E10 most 

appropriately reflects in-use gasoline around the country today and into the 

foreseeable future, and thus we are finalizing E10 for the test fuel. In 

addition, as discussed in Section IV.F.1, we are finalizing a fuel volatility

specification for test fuel of 9 psi RVP, as proposed.

 We are finalizing a set of standards for PM as measured on the aggressivedriving segment of the SFTP test cycle (the US06 cycle) based on US06 PM 

test data that we published as part of the NPRM, along with more recent test 

data developed by California. Our review of these data has led us to finalize 

numerically lower levels for the US06 PM standards than we proposed. The 

data presented in the NPRM as well as the data provided by California clearly

show that the proposed US06 PM standards were inappropriately high, that 

US06 PM emissions are not closely related to vehicle weight, and that lower 

values for the standards would achieve the goal of the program to bring all 

vehicles in the light-duty fleet to the US06 PM levels that are being met by

many vehicles today. Based on the body of available data, we are establishing 

6 mg/mi as the long-term US06 PM standard. (This compares to the proposed 

standards of 10 and 20 mg/mi for lighter and heavier light-duty vehicles, 

respectively.) However, because there remains some uncertainty about how 

manufacturers will achieve this level in the early years of the program, we are 

setting the standard at 10 mg/mi for the early years of the program, for MYs 

2017 and 2018. Similarly, we are providing a less-stringent standard of 10 

mg/mi for testing of in-use vehicles in recognition of the challenges of the 

requirements as vehicles age. 

 In the Tier 3 program, as for vehicle emission control programs in the past, 

manufacturers are responsible for the emissions performance of the vehicle for 
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a specified “useful life” of the vehicle. EPA proposed that vehicles meet the 

Tier 3 standards for 150,000 miles or 15 years, identical to the LEV III 

program’s approach. We proposed an option for lighter light-duty vehicles to 

certify to a shorter useful life of 120,000 miles or 10 (or 11, as applicable) 

years, as set in the Tier 2 program. We proposed that manufacturers 

certifying to the shorter useful life would need to meet numerically lower 

NMOG+NOX standards (85 percent of the respective 150,000-mile 

NMOG+NOX standards). We also proposed that a manufacturer choosing the 

shorter useful life for one vehicle model would need to use that useful life and 

associated standards for all of its lighter vehicles. Auto industry commenters 

stated that applying the provision across a manufacturer’s fleet would create 

an onerous compliance burden. We have reconsidered our proposed 

approach, and as discussed in Section IV.A.7.c below, we will allow a 

manufacturer to split its lighter light-duty fleet among models certified for 

either the 150,000 mile or 120,000 mile useful life and associated standards. 

 Another area of substantial comment, primarily from the petroleum refining 

industry, questioned the technological need of auto manufacturers for lower 

in-use sulfur levels in order to meet the Tier 3 vehicle emission standards. In 

contrast, auto manufacturers and emissions control system manufacturers 

commented that lower sulfur gasoline is critical to meet the Tier 3 standards. 

After careful consideration of the comments, we continue to believe that the 

large body of data presented in the NPRM, supplemented by newer data that 

consistently reinforces the earlier conclusions, strongly supports our 

determination of the need for average in-use gasoline sulfur levels to be at 10 

ppm sulfur or lower for manufacturers to meet the Tier 3 vehicle standards 

across their fleets for the useful life of the vehicles. See Section IV.A.6 below 

for a detailed discussion of the need for gasoline sulfur control. 

b. Structure of the Primary Tier 3 Tailpipe Standards

As proposed, compliance with the standards is based on vehicle testing using test 

procedures that represent a range of vehicle operation, including the Federal Test 

Procedure (FTP) and the Supplemental Federal Test Procedure (SFTP). The Tier 3 FTP 

and SFTP NMOG+NOX standards are fleet-average standards, meaning that the 

manufacturer calculates the sales-weighted average emissions of the vehicles it sells in 

each model year, accounting for any Tier 3 emissions credits or deficits, and compares 

that average to the applicable standard for that model year. The fleet average standards 

for NMOG+NOX evaluated over the FTP are the same values as proposed and are 

summarized in Table IV-2 and discussed in detail below. For lighter light-duty vehicles, 

the standards begin in MY 2017 at a level representing a 46 percent reduction from the 

current Tier 2 requirements for lighter vehicles and then become increasingly stringent, 

culminating in an 81 percent reduction in MY 2025. The FTP NMOG+NOX program 

includes separate fleet average standards for heavier vehicles that begin in MY 2018 and 
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then converge with the standards for lighter vehicles at 30 milligrams per mile (mg/mi) in 

MY 2025 and later, as proposed.251,252

Manufacturers will determine their fleet average FTP NMOG+NOX emission 

values as we proposed, based on the per-vehicle “bin standards” to which they certify

each vehicle model. Manufacturers will be free to certify vehicles to any of the bins, so 

long as the sales-weighted average of the NMOG+NOX values from the selected bins 

meets the fleet average standard for that model year. Table IV-1 presents the per-vehicle 

bin standards. Similarly, the fleet average NMOG+NOX standards measured over the 

SFTP are summarized in Table IV-4 and discussed in detail below. The SFTP 

NMOG+NOX fleet average standards decline from MY 2017 until MY 2025. In this 

case, the same standards apply to both lighter and heavier vehicles. In MY 2025, the 

SFTP NMOG+NOX standard reaches its fully phased-in fleet average level of 50 mg/mi. 

Also as proposed, the new Tier 3 PM standards apply to each vehicle separately. 

The PM standards are per-vehicle cap standards and not fleet-average standards. Also, in 

contrast to the declining NMOG+NOX standards, the PM standard on the FTP is a 

constant 3 mg/mi for all vehicles and for all model years, phasing in to an increasing 

percentage of vehicle sales beginning in MY 2017 for vehicles at or below 6,000 lbs 

Gross Vehicle Weight Rating (GVWR) and in MY 2018 for vehicles above 6,000 lbs 

GVWR. As discussed in Section IV.A.3.b above, based on data generated by EPA and 

CARB test programs, most current light-duty vehicles are already performing at or below 

the 3 mg/mi level. However, some vehicles are emitting above this level, due to such 

factors as excessive fueling during cold start and combustion chamber and fuel system 

designs that are not optimized for low PM emissions. The intent of the 3 mg/mi standard 

is to bring all light-duty vehicles to the PM level typical of that being demonstrated by

most light-duty vehicles today. To address the uncertainties that will accompany the 

introduction of new technologies, the program includes a separate in-use FTP PM 

standard of 6 mg/mi for the testing of in-use vehicles during the phase-in period, as 

proposed, as described in more detail below. 

As presented in Table IV-3, for vehicles at or below 6000 lbs GVWR, these FTP 

PM certification and in-use standards phase in over several years, beginning with a 

requirement that at least 20 percent of a company’s U.S. sales of these vehicles comply

with the Tier 3 standards in MY 2017. We are also finalizing an option for a 

manufacturer to choose to certify 10 percent of its total light-duty fleet sales – including 

LDVs and LDT over 6,000 lbs GVWR and MDPVs – to the Tier 3 FTP PM standards in 

 

251 The declining NMOG+NOX fleet-average standards consist of one set of declining standards that applies

to light-duty vehicles (LDVs) and small light trucks (LDT1s) and a second set of declining standards that 

applies to heavier light trucks (LDT2s, LDT3s. LDT4s), and MDPVs.

252 This preamble presents the new Tier 3 standards in terms of milligrams per mile (mg/mi) for 

convenience. Throughout the associated Tier 3 regulatory language we continue to present the standards in 

terms of grams per mile (g/mi) for consistency with earlier programs. 
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MY 2017. Manufacturers would reach a 100 percent compliance requirement in MY 

2021. 

Finally, the Tier 3 program includes PM standards evaluated over the US06 cycle 

(a component of the SFTP test that captures higher speeds and accelerations). Based on 

emissions test data presented in the NPRM and additional data submitted in public 

comments, and as presented in Table IV-5 and further discussed in Section IV.A.4.b 

below, we are establishing a single long-term US06 PM standard of 6 mg/mi for both 

lighter and heavier vehicles, a level that is numerically lower than what we proposed. 

However, because there remains some uncertainty about how manufacturers will decide 

to achieve this level in the early years of the program, we are setting the standard through 

MY 2018 at 10 mg/mi. The US06 PM standards phase in using the same 20-20-40-70-

100 percent schedule, and on the same vehicles, as the new FTP PM standards. The 10 

mg/mi standard applies in MYs 2017 and 2018 (at a percent-of-sales requirement of 20 

percent, and the long-term 6 mg/mi standard applies in MYs 2019 and later, increasing 

from 40 to 100 percent of sales. This US06 standard will apply to the same vehicle 

models that a manufacturer chooses to certify to the FTP PM standard during the percent 

phase-in period. As in the case of the FTP PM standards, the intent of the standard is to 

bring the emission performance of all vehicles to that already being demonstrated by 

many vehicles in the current light-duty fleet. As proposed, we include a separate in-use 

US06 PM standard during in the middle years of the program, but at a different numerical 

level and during different years than proposed (as discussed in Section IV.A.4.b below). 

We did not propose new emission requirements for any vehicle or fuel over the 

cold temperature test cycles (i.e., the 20 °F cold carbon monoxide (CO) and non-methane 

hydrocarbon (NMHC) tests), but requested comment on that decision. Only the 

automakers commented on this topic, agreeing with EPA’s approach of not changing its 

cold temperature requirements. As indicated in the proposal, we are not establishing any 

new cold temperature requirements in this rule. 

c. Alternate Phase-In Schedules

For heavier light-duty vehicles (i.e., LDVs and LDTs greater than 6,000 lbs 

GVWR, plus MDPVs), EPA is also finalizing alternative phase-in schedules for each of 

the four primary vehicle emission standards: FTP NMOG+NOX, FTP PM, SFTP 

NMOG+NOX, and US06 PM.253 These alternative phase-ins are available if a 

manufacturer prefers stable standards and four full years of lead time, as specified in the 

Clean Air Act for heavier vehicles. We describe each of the alternative phase-ins in more 

detail below, including several ways in which we have revised the proposed provisions. 

EPA received comment on the proposed alternative phase-in provisions, primarily

from automakers and their trade associations. These comments questioned whether the 

 

253 Tier 3 standards for CO and HCHO phase in with the NMOG+NOx standards, as applicable.
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proposed structure of and restrictions on the use of the alternative phase-ins were so 

onerous as to unduly restrict a manufacturer from choosing the alternative phase-ins and 

their lead time and stability provisions as set forth in the Clean Air Act. The commenters 

criticized the proposed requirement that a manufacturer using the alternative phase-ins 

apply the alternative schedules to its entire light-duty fleet, both below and above 6,000 

lbs GVWR. EPA had proposed this provision to minimize the complexity of complying 

with the alternative phase-in if a manufacturer’s heavier and lighter light-duty vehicles 

had different compliance structures. 

In consideration of these concerns, we have removed from the alternative phase-in 

provisions the requirement that a manufacturer apply the alternative schedules to its 

entire light-duty fleet including vehicles below 6,000 lbs GVWR. For the practical 

functioning of the program, the final rule requires that any manufacturer choosing to use 

the alternative phase-in apply all four alternative phase-in schedules to its entire lightduty fleet above 6,000 lbs GVWR. We believe that the alternative phase-ins allow 

manufacturers to comply with emission standards in a time frame that is clearly feasible 

and fully compliant with the CAA requirements for lead time and regulatory stability. To 

the extent that manufacturers choose to use them, the alternative would result in overall 

emission reductions essentially identical to those of the primary program. 

The alternative phase-in schedules would begin to apply to each vehicle for either 

MY 2019 or MY 2020, depending on exactly when the manufacturer begins production 

of the vehicle. (See Section 86.1811-17(b)(8)(i) for how we implement this provision.) 

For models that begin MY 2019 production after the fourth anniversary of the signing of 

this final rule, the alternative phase-in would provide four full years of lead time and 

would first apply for MY 2019. The phase-in obligation would be calculated based only 

on those vehicles beginning production after the fourth anniversary date. For models 

beginning production before that date, the alternative phase-in would first apply for MY 

2020, and the phase-in percentage for MY 2020 would be based on the manufacturer’s 

entire fleet of heavier light-duty vehicles. Based on historical certification patterns, few 

models begin production before mid-calendar-year, so we expect that the vast majority of 

MY 2019 vehicles will begin production after the 4-year anniversary and thus the 

alternative phase-ins, if chosen, will typically apply beginning in MY 2019. 

At the time of certification for MY 2018, a manufacturer must declare whether it 

intends to apply the alternative phase-in schedules to its heavier light-duty vehicles. A 

manufacturer choosing the alternative phase-ins would be committed to this phase-in 

approach for the duration of the phase-ins, and could not later choose the fleet-average 

approach for NMOG+ NOX standards. For all vehicles below 6,000 lbs GVWR, the 

primary program will apply, beginning in MY 2017. For a manufacture’s vehicles 

subject to the alternative phase-ins, there would be no new tailpipe emissions 

requirements beyond the Tier 2 program until the beginning of the alternative phase-in 

schedules; that is, MY 2019 or 2020, as explained above.
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As discussed above, a manufacturer choosing the alternative phase-in approach 

for its heavier light-duty vehicles would be required to use all four phase-ins together. 

The next paragraphs explain how each of the alternative phase-ins requires an increasing 

percent of the manufacturer’s sales to comply with the alternative standards. Thus, until 

the end of the phase-ins, some percent of a manufacturer’s affected vehicles will meet the 

new standard and the remainder of that year’s sales will not yet comply with Tier 3. For 

the practical functioning of the program, a manufacturer choosing the alternative phaseins would be required to comply with exactly the same segment of their fleet in each 

model year for all four alternative phase-ins. For example, a manufacturer that complies 

with the 70 percent MY 2020 requirement for the FTP NMOG+NOX standard with a 

segment of its vehicle fleet must meet the 70 percent MY 2020 requirement for the FTP 

PM standard with the same set of vehicles. Vehicles covered by the alternative phase-in 

programs would be considered “Final Tier 3” vehicles and thus would also need to 

comply with the Tier 3 certification fuel and full useful life provisions. 

For the FTP and SFTP NMOG+NOX alternative phase-in schedules, once the 

phase-in is complete for a segment of a manufacturer’s fleet, the standards continue for 

that set of vehicles through MY 2024, after which the full Tier 3 program applies 

regardless of the phase-in strategy. Thus, the fleet-average standards that decline through 

MY 2024 do not apply for these vehicles. 

Although manufacturers would implement all four alternative phase-in schedules 

together, as discussed above, each alternative phase-in has unique characteristics. The 

following paragraphs explain the unique provisions of each. 

(1) Alternative Phase-In Schedule for the FTP NMOG+NOX Standard

Instead of the primary FTP NMOG+ NOX declining fleet average standards, a 

manufacturer choosing the alternative phase-ins would comply with a stable fleet average 

FTP NMOG+NOX standard of 30 mg/mi that would apply to an increasing percentage of 

a manufacturer’s combined sales of LDVs and LDTs above 6,000 lbs GVWR and 

MDPVs. This percent phase-in would match the percentages in the primary PM percent 

phase-in schedule, as discussed above – specifically, 40 percent of MY 2019 heavier 

light-duty vehicles (excluding those vehicles with production beginning before the 4-year 

anniversary), 70 percent of all of its heavier light-duty vehicles in MY 2020, and 100 

percent compliance in MY 2021 and later model years. 

(2) Alternative Phase-In Schedule for the FTP PM Standard

Instead of the primary FTP PM percent phase-in schedule, a manufacturer 

choosing the alternative phase-ins would postpone the beginning of its FTP PM phase-in 

for its LDVs and LDTs above 6,000 lbs GVWR and MDPVs until MY 2019 or 2020 

(depending on the dates production begins for its vehicle models, as discussed above). 

The manufacturer would then comply with the 3 mg/mi per-vehicle FTP PM standard 

(and the 6 mg/mi in-use standard) on an increasing percentage of these vehicles, 
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following the 40-70-100 percentage phase-in of the primary PM program -- specifically, 

40 percent of MY 2019 heavier light-duty vehicles (excluding those vehicles with 

production beginning before the 4-year anniversary), 70 percent of all of its heavier lightduty vehicles in MY 2020, and 100 percent compliance in MY 2021 and later model 

years. 

(3) Alternative Phase-In Schedule for the SFTP NMOG+NOX Standard

As with the other alternative phase-ins, instead of the primary SFTP NMOG+ 

NOX declining fleet average standards, a manufacturer choosing the alternative phase-ins 

would comply with a stable fleet average SFTP NMOG+NOX standard of 50 mg/mi that 

would apply to an increasing percentage of a manufacturer’s combined sales of LDVs 

and LDTs above 6000 lbs GVWR and MDPVs. This percent phase-in again would match 

the percentages in the primary PM percent phase-in schedule, as discussed above –

specifically, 40 percent of MY 2019 heavier light-duty vehicles (excluding those vehicles 

with production beginning before the 4-year anniversary), 70 percent of all of its heavier 

light-duty vehicles in MY 2020, and 100 percent compliance in MY 2021 and later model 

years.

(4) Alternative Phase-In Schedule for the US06 PM Standard

Finally, instead of the primary US06 PM percent phase-in schedule, a 

manufacturer choosing the alternative phase-ins would postpone the beginning of the 

US06 phase-in for its LDVs and LDTs above 6,000 lbs GVWR and MDPVs until MY 

2019 or 2020 (depending on the dates production begins for its vehicle models, as 

discussed above). The manufacturer would then comply with the 10 mg/mi US06 PM 

standard for 40 percent of MY 2019 heavier light-duty vehicles (excluding those vehicles 

with production beginning before the 4-year anniversary), 70 percent of all of its heavier 

light-duty vehicles in MY 2020, with 100 percent compliance in MY 2021, and then 100 

percent compliance with the 6 mg/mi standard in MY 2022 and later model years.

The next sections describe in more detail the new Tier 3 standards, how they will 

be implemented over time, and the technological approaches that we believe are or will 

be available to manufacturers in order to comply.

3. FTP Standards

As summarized above, we are finalizing, largely as proposed, new standards for 

the primary pollutants of concern for this rule (NMOG, NOX, and PM) as measured on 

the FTP. The following paragraphs describe in more detail these FTP standards for 

NMOG+NOX and PM, as well as for carbon monoxide (CO) and formaldehyde (HCHO). 
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a. FTP NMOG+NOX Standards

The Tier 3 NMOG and NOX standards are expressed in terms of the sum of the 

two pollutants -- NMOG+NOX in mg/mi.254 We received no comments recommending a 

different approach. The California LEV III standards are also expressed as 

NMOG+NOX; aligning Tier 3 with LEV III is an important element of facilitating a 

national program.

EPA received a number of comments about how the proposed NMOG+ NOX

standards transition from the existing Tier 2 standards, but there was little comment 

recommending different levels of the standards themselves, especially later in the 

program. Based on our extensive evaluation of existing and emerging vehicle 

technologies (see Section IV.A.5) and the level of sulfur in gasoline that will be available 

during the implementation timeframe of this rule, and considering the comments we 

received, we continue to believe that the fully phased-in level for the fleet-average FTP 

NMOG+NOx standard of 30 mg/mi is the most stringent level that we can reasonably 

establish. As discussed in Sections IV.A.5 and IV.A.6 below, when necessary margins of 

compliance and the demonstrated effects of fuel sulfur on emissions performance are 

considered, the 30 mg/mi standard is effectively very close to zero. The 30 mg/mi Tier 3 

NMOG+NOX standard is also consistent with the final LEV III standard.

A key compliance mechanism adapted from the Tier 2 program is a “bin” 

structure for the FTP emission standards. For these purposes, a bin is a set of several 

standards that must be complied with as a group. Thus, as proposed, each FTP Tier 3 bin 

has an NMOG+NOX standard and a PM standard, as well as CO and HCHO standards. 

We intend for the Tier 3 CO and HCHO standards to prevent new engine and 

emission control designs that result in increases in CO and HCHO emissions, compared 

to levels being achieved today. The standards are based on the comparable current LEV 

II and Tier 2 bin standards for these pollutants, which we believe are sufficiently

protective at this time. There were no comments on the proposed CO and HCHO 

standards. The current standards are not technology-forcing, and we believe that this will 

continue to be the case as Tier 3 technologies are developed.

Table IV-1 presents the bin structure for light-duty vehicle, light-duty truck, and 

MDPV FTP standards.

 

254 See California Low-Emission Vehicles (LEV) & GHG 2012 regulations adopted by the State of 

California Air Resources Board, March 22, 2012, Resolution 12-21 incorporating by reference Resolution 

12-11, which was adopted January 26, 2012. Available at 

http://www.arb.ca.gov/regact/2012/leviiighg2012/leviiighg2012.htm (last accessed December 2, 2013).
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Table IV-1 Tier 3 FTP Standards for LDVs, LDTs and MDPVs (mg/mi)

Bin NMOG+ NOX

(mg/mi)

PMa

(mg/mi)

CO

(g/mi)

HCHO

(mg/mi)

Bin 160 160 3 4.2 4

Bin 125 125 3 2.1 4

Bin 70 70 3 1.7 4

Bin 50 50 3 1.7 4

Bin 30 30 3 1.0 4

Bin 20 20 3 1.0 4

Bin 0 0 0 0 0

a

 In MYs 2017-20, the PM standard applies only to that segment of a manufacturer’s vehicles covered by 

the percent of sales phase-in for that model year. 

Consistent with the Tier 2 principle of vehicle and fuel neutrality, the same Tier 3 

standards apply to all LDVs, LDTs, or MDPVs, regardless of the fuel they use, as 

proposed. That is, vehicles certified to operate on any fuel (e.g., gasoline, diesel fuel, 

E85, CNG, LNG, hydrogen, and methanol) are all subject to the same standards. 

The Tier 3 NMOG+NOX standards as measured on the FTP will reduce the 

combined fleet-average emissions gradually from MY 2017 through 2025, as shown in 

Table IV-2 below. Beginning in MY 2017, there are two separate sets of fleet-average 

standards for, first, LDVs and LDT1s and, second, all other LDTs (LDT2s, LDT3s, and 

LDT4s) and MDPVs. Both fleet-average standards decline annually, converging in MY 

2025. These declining average standards are identical to CARB’s LEV III standards.255

As proposed and as discussed above (Section IV.A.2.a), the declining fleetaverage NMOG+NOX FTP standards begin in MY 2017 for light-duty vehicles and lightduty trucks with a GVWR up to and including 6,000 lbs and in MY 2018 for light-duty 

vehicles and light-duty trucks with a GVWR greater than 6,000 lbs and MDPVs. The 

standards apply to the heavier vehicles a year later to facilitate the transition to a 50-state 

program for all manufacturers. During this transition period, as described above, there 

will be two fleet-average NMOG+NOX standards for each model year, one for LDVs and 

LDT1s and one for all other LDTs (LDT2s, LDT3s, and LDT4s) and for MDPVs that 

decline essentially linearly from MY 2017 through MY 2025. At that point, the two 

fleet-average standards converge and stabilize for all later model years at the same level, 

30 mg/mi, as shown in Table IV-2. 

 

255 See California Low-Emission Vehicles (LEV) & GHG 2012 regulations adopted by the State of 

California Air Resources Board, March 22, 2012, Resolution 12-21 incorporating by reference Resolution 

12-11, which was adopted January 26, 2012. Available at 

http://www.arb.ca.gov/regact/2012/leviiighg2012/leviiighg2012.htm (last accessed January 14, 2014).
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Table IV-2 Tier 3 LDV, LDT, and MDPV Fleet Average FTP NMOG+NOX

Standards (mg/mi) 

Model Year

2017a2018 2019 2020 2021 2022 2023 2024 2025 

and later

LDV/LDT1b86 79 72 65 58 51 44 37

LDT2,3,4 and 30

MDPV

101 92 83 74 65 56 47 38

a

For LDVs and LDTs over 6,000 lbs GVWR and MDPVs, the fleet average standards apply beginning in 

MY 2018.

b These standards apply for a 150,000 mile useful life. Manufacturers can choose to certify their LDVs and 

LDV1s to a useful life of 120,000 miles. If a vehicle model is certified to the shorter useful life, a 

proportionally lower numerical fleet average standard applies, calculated by multiplying the respective 

150,000 mile standard by 0.85 and rounding to the nearest mg/mi. See Section IV.A.7.c.

As discussed above (Section IV.A.2.c), for LDVs and LDTs above 6,000 lbs 

GVWR and MDPVs, EPA is also providing an alternative phase-in of the fleet-average 

30 mg/mi FTP NMOG+NOX standard. 

b. FTP PM Standards

We are establishing new FTP standards for PM emissions at the proposed levels --

3 mg/mi, with a temporary standard of 6 mg/mi for in-use vehicle testing -- as 

summarized in Table IV-3 below. These levels are intended to ensure that all new 

vehicles will perform at a level representing what is already being achieved by welldesigned emission control technologies today. 

Many commenters were either silent on or supportive of the proposed FTP PM 

standard levels. However, some commenters – including CARB and several NGOs and 

auto industry suppliers -- supported a more stringent standard of 1 mg/mi, which the 

California LEV III program phases in beginning in MY 2025. After detailed 

consideration of these comments and information available at this time, we continue to 

believe that the PM standards that we are finalizing for the federal Tier 3 program are the 

most stringent technically feasible standards within the implementation timeframe of this 

rule. (See Section 1.5.1 of the RIA.) We will continue to work closely with CARB in 

this area. Specifically, our agencies will continue our parallel evaluations of how 

improved gravimetric PM measurement methods can reduce PM mass measurement 

variability at very low PM levels and how this relates to the evolving technological 

capabilities of automakers to reach very low PM levels with sufficient compliance 

margins. 

PM emissions over the FTP are generally attributed to the cold start, when PM 

formation from combustion of the fuel is facilitated by the operating conditions, 
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including a cold combustion chamber and fuel enrichment. During cold-start operation, 

PM control is less effective, especially the oxidation by the catalytic converter of semivolatile organic compounds from the lubricating oil. We believe that for vehicles that are 

not already at the Tier 3 levels, the new standards can be achieved with improvements to 

the fuel controls during the cold start, without the need for any new technology or 

hardware. We also expect that manufacturers will pay close attention to maintaining low 

PM emissions during the implementation of newer technologies like gasoline direct 

injection (GDI) and turbocharged engines. Improvements in cold-start exhaust catalyst 

performance for NMOG+NOx control will also reduce emissions of semi-volatile organic 

PM. For these reasons, cold start PM levels are relatively independent of vehicle

application and therefore we are finalizing a single FTP PM standard for all light-duty

vehicles, as proposed. 

Unlike the NMOG+NOX FTP standard, it is not necessary for the FTP PM 

standard to phase in on a declining curve over time, since most manufacturers are already 

producing vehicles that meet the new standards. We are finalizing the proposed PM FTP 

percent-of-sales phase-in during the first 5 years of the Tier 3 program in response to 

concerns expressed by automakers about logistical, facilities, and compliance challenges 

with a standard in the range of 3 mg/mi in the early years of the program. Beginning in 

MY 2017 (and in MY 2018 for LDVs and LDTs over 6,000 lbs GVWR and MDPVs), 

manufacturers will need to comply with the PM standard with a minimum of 20 percent 

of their U.S. sales. As shown in Table IV-3, the percentage of the manufacturer’s sales 

that need to comply increases each year, reaching 100 percent in MY 2021. In addition 

to this percent phase-in, we are also establishing, as proposed, a separate PM standard of 

6 mg/mi that will apply only for in-use testing of vehicles certified to the new standards, 

and only during the percent phase-in period. 

Due to the MY 2018 start date for vehicles over 6,000 lbs GVWR, manufacturers 

that have few or no vehicle models over 6,000 lbs GVWR will be required to certify a 

larger percentage of their total light-duty sales in MY 2017 than full line manufacturers. 

While we believe that most manufacturers will likely choose a single large-volume 

durability group to meet the 2017 requirements, we are also including an option that a 

manufacturer could use to comply with the MY 2017 PM requirements. Under this 

option, a manufacturer may choose to certify 10 percent of its total light-duty vehicle 

sales in MY 2017 to the new PM standards, including light-duty vehicles over 6,000 lbs. 

This approach is consistent with the CARB LEV III program, which requires that 10 

percent of all light-duty vehicle sales meet the new PM standards in MY 2017. 

Because of the expected time and expense of performing emission tests on the 

improved PM test procedures, we are limiting the number of tests using the new 

procedures that a manufacturer needs to perform at certification and during in-use testing, 

as proposed. Specifically, manufacturers will only be required to test vehicles 
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representing a minimum of 25 percent of a model’s durability test groups during 

certification each model year (and a minimum of 2 durability groups).256 Manufacturers 

may select which durability groups to test, but will need to rotate the groups tested each 

year to eventually cover their whole fleet. Similarly, manufacturers performing in-use 

testing under the In-Use Verification Program can limit their testing to 50 percent of their 

low- and high-mileage test vehicles. Again, manufacturers will need to rotate their 

vehicle models so that each model will be tested every other year. Overall, we believe 

that the flexibility that these provisions provide will facilitate the expeditious 

implementation of the Tier 3 program, with no significant impact on the benefits of the 

program.

Table IV-3 Summary of Tier 3 LDV, LDT, and MDPV FTP Standards

Program Element Units

Model Year Notes

2017a2018 2019 2020 2021 2022 2023+

NMOG+NOX

Standard

(fleet average)

mg/mi Per declining fleet averages (see Table IV-2)

b

PM Standards

Phase-in % 20c20 40 70 100 100 100

FTP

Certification mg/mi 3 3 3 3 3 3 3 Note d

In-use mg/mi 6 6 6 6 6 3 3 Note e

a

For LDVs and LDTs above 6,000 lbs GVWR and MDPVs, the FTP PM standards apply beginning in MY 

2018.

b The percent phase-in does not apply to the declining fleet average standards. 

c Manufacturers comply in MY 2017 with 20 percent of their LDV and LDT fleet under 6,000 lbs GVWR, or 

alternatively with 10 percent of their total LDV, LDT, and MDPV fleet. 

d Manufacturers must test 25 percent of each model year’s durability groups, and a minimum of 2.

e Manufacturers must test 50 percent of their combined low- and high- mileage in-use vehicles. 

As discussed in Section IV.A.2.c above, for LDVs and LDTs above 6,000 lbs 

GVWR and MDPVs, EPA is providing an alternative phase-in of the 3 mg/mi FTP PM 

standard. 

 

256 Durability groups are a subset of engine families. Several engine families may have the same durability 

group.
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4. SFTP Standards 

In addition to addressing vehicle emissions during typical driving, as addressed by

the FTP standards presented above, the Tier 3 program also addresses emissions during 

more severe driving conditions. Thus, we are finalizing NMOG+NOX and PM standards 

as measured on the SFTP. The SFTP (and specifically the US06 component of the test) 

is designed to simulate, among other conditions, higher speeds and higher acceleration 

rates, and thus higher loads. As described below, most commenters were supportive of or 

silent on the proposed SFTP NMOG+NOX standards and the associated declining fleetaverage phase-in schedule, but several commenters stated that the level of the standards 

should be more stringent than proposed. Based on our analysis of the stringency of the 

program, discussed in Section IV.A.5 below and in Chapter 1 of the RIA, we disagree 

that more stringent SFTP NMOG+ NOX standards are necessary or appropriate at this 

time, and we are finalizing the standards and phase-in schedule as proposed. However, 

we are finalizing more stringent SFTP standards for PM, which focus on the US06 test 

component, based on newer data and public comments. These are also described below.

The Tier 3 SFTP standards are necessary to address emissions during high-load 

conditions, when engines can go into a fuel “enrichment” mode and the engine’s controls 

may temporarily create a rich air/fuel mixture to protect exhaust components from 

thermal damage. Enrichment can increase emissions of NMOG+NOX and PM, primarily

due to the incomplete combustion that occurs under rich conditions and the diminished 

effectiveness of the catalyst in these circumstances. However, enrichment can be 

minimized or eliminated in current and future engines, where components can be 

thermally protected even under high-load conditions by careful electronic management of 

the air/fuel mixture and the combustion process. We are finalizing these SFTP standards, 

as well as limitations on the amount of enrichment that drivers can command (see Section 

IV.A.4.c below) to address this important source of vehicle emission. 

We are also finalizing an SFTP composite CO standard of 4.2 g/mi for all model 

years 2017 (or 2018 for LDVs and LDTs over 6000 lbs GVWR and MDPVs) and later. 

This standard represents no effective change from the current Tier 2 SFTP CO standard, 

which we believe is already at a level that is sufficiently stringent. 

a. SFTP NMOG+NOX Standards

We are finalizing the Tier 3 SFTP NMOG+NOX standards and declining fleetaverage phase-in schedule as proposed and as presented in Table IV-5 below. Most 

commenters were generally supportive of these standards or silent about them. However, 

several commenters stated that the proposed standards are too lenient, based on their 

evaluation of vehicle emission test data we presented in the NPRM. We have considered 

these comments and have reviewed the data from the NPRM. Our conclusion from that 

data continues to be that the SFTP NMOG+NOx emission levels that we are finalizing 

ensure that manufacturers essentially eliminate fuel enrichment events and their 

emissions consequences, thereby resulting in important emissions reductions. See 
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Chapter 1 of the RIA for an analysis of this data. We do not believe that significant 

additional reductions would result from SFTP weighted NMOG+NOX standards more 

stringent than the 50 mg/mi fully phased-in level. In addition, we believe that the 50 

mg/mi standard will ensure that the SFTP performance of future vehicles with future 

technologies continues to be comparable to that of the current fleet. The SFTP emissions 

value for certification of gaseous pollutants will continue to be calculated as a weighted 

composite value of emissions on three cycles (0.35 x FTP + 0.28 x US06 + 0.37 x SC03), 

as is done for the Tier 2 SFTP standards. 

To provide flexibility in meeting the fleet-average standards, manufacturers will, 

as proposed, determine the specific SFTP composite standard for each individual vehicle 

family and report that self-selected standard and the measured emission performance. 

(These self-selected standards are analogous to “family emission limits,” or “FELs,” used 

in other programs (e.g., heavy-duty highway engine standards).) For each family, a 

manufacturer will choose any composite NMOG+NOX standard, up to 180 mg/mi, in 

even 10 mg/mi increments. The manufacturer will then calculate the sales-weighted 

average of all the selected standards of the families across its fleet and compare that 

emissions value to the applicable fleet-average standards for that model year. Table IV-4

presents the declining fleet-average SFTP NMOG+NOX standards.

As discussed in Section IV.A.2.c above, for LDVs and LDTs above 6,000 lbs 

GVWR and MDPVs, EPA is providing an alternative phase-in of the 50 mg/mi SFTP 

NMOG+NOX standard. 

b. US06 PM Standards

We are finalizing a single short-term US06 PM standard of 10 mg/mi for MYs 

2017 and 2018 (or only for MY 2018 for LDVs and LDTs over 6,000 lbs GVWR and 

MDPVs) and a single long-term standard of 6 mg/mi for MY 2019 and later. These 

standards are numerically lower than those we proposed, and less complex in their 

structure. As discussed below and in Chapter 1 of the RIA, a substantial body of more 

recent PM data from a variety of vehicles tested on the US06 cycle has given us greater 

understanding of the feasible level of control of these emissions, both currently and in the 

timeframe of the Tier 3 standards, including what level of control we may reasonably 

require for the light-duty fleet. The standards we are finalizing reflect this review. Much 

of the more recent data was developed late in the development of the NPRM and, 

although we made it available in the rulemaking docket to inform potential commenters, 

the proposed standards did not reflect consideration of the newer data. Since the NPRM, 

additional data from CARB have become available, and we have considered all of this 

information in finalizing the US06 PM standards.

We believe that the fully phased-in US06 PM standard of 6 mg/mi will achieve 

the goal that we presented in the NPRM – to maintain the performance being achieved by 

current well-performing vehicles taking into account reasonable compliance margins. 

Comments from stakeholders representing states, including CARB, and several NGOs 
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urged EPA to finalize more stringent standards than those proposed, in some cases 

advocating for standards below 6 mg/mi. Conversely, auto industry commenters 

generally supported the proposed standards. We have concluded that the body of recent 

data clearly shows that the long-term 6 mg/mi standard, is the appropriate level to prevent 

any significant “backsliding” in US06 PM emissions as new vehicles and technologies 

enter the fleet. At the same time, the 6 mg/mi standard provides a reasonable compliance 

margin -- about 50% above the average levels of current vehicles, which are averaging 

about 4 mg/mi. A long-term standard numerically lower than 6 mg/mi would run 

counter to our intent to bring the emissions performance of all vehicles to that already 

being demonstrated by many vehicles in the current light-duty fleet. We believe the 

long-term US06 PM standard we are finalizing is appropriate based on all of the 

information available at this time and will not hinder introduction of new technologies 

manufacturers may choose for compliance with the other Tier 3 standards or other rules. 

The short-term, less-stringent US06 standard of 10 mg/mi (applicable in MYs 

2017 and 2018) responds to automaker concerns about uncertainties stemming from 

simultaneous regulatory requirements and rapidly evolving exhaust and engine 

technologies in the coming years. We recognize that vehicle control technologies for 

both criteria and GHG emissions are evolving and will continue to do so, including an 

expected expansion of gasoline direct injection (GDI) technologies (see IV.A.5.c and the 

RIA). Also, the transition to lower sulfur in-use gasoline required by this rule may create 

temporary additional challenges in consistently achieving lower US06 PM emissions (see 

IV.A.6 and the RIA). We believe that most manufacturers will implement similar if not 

identical emission control strategies to comply (or, more often, to continue to comply

with) with both the 10 mg/mi and the 6 mg/mi standards. In so doing, we expect them to 

use the temporary additional compliance margin provided by the 10 mg/mi standard to 

reduce uncertainties about potential variability in performance (in use and, in particular, 

later in vehicle life) during the early years of developing and commercializing their 

control technologies.257 

The 10 mg/mi standard will expire after MY 2018, and the long-term standard of 

6 mg/mi will take effect. As the implementation of the program continues, we believe a 

limited degree of relief for testing of in-use vehicles is appropriate. Manufacturers 

commented that because of the industry’s general lack of experience with stringent PM 

standards, especially as the newly-designed vehicles age, less stringent standards for inuse testing would reduce near-term concerns about performance variability early in the 

program. We agree, and we are finalizing a separate standard of 10 mg/mi for in-use 

 

257 We note that the purpose of the percent phase-in schedule for the FTP and US06 PM standards is to 

facilitate the expansion of manufacturers’ PM testing facilities, which have been relatively limited in their 

availability prior to these new emission standards. While effectively providing more time for technology 

development as well as for expansion of facilities, we believe that the PM standards are designed to be fully 

feasible in the early years of the program and do not themselves require the phase-in relief, especially given 

the short-term 10 mg/mi standard and the temporary relaxed in-use testing standards.
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vehicle testing for the intermediate years of the program, MYs 2019 through MY 2023. 

This standard is numerically lower than the proposed in-use standards -- again because of 

the availability of improved US06 test data as described above -- but the purpose of 

providing an in-use standard remains the same. The in-use standard, in conjunction with 

the short-term 10 mg/mi standard represents a longer duration for the in-use standard than 

we had proposed, again based on comments from the industry about their compliance 

concerns with new US06 standards. For MY 2024 and later, there will be no separate inuse standard and all vehicles will need to meet the long-term standard at certification and 

in use. 

EPA proposed that different US06 PM standards apply to lighter and heavier 

vehicles. The newer US06 PM test data discussed above also make clear that the US06 

PM performance of current vehicles is not closely related to vehicle weight, although the 

earlier data had indicated that this might be the case. Several commenters urged EPA to 

finalize a single standard for vehicles above and below 6,000 lbs GVWR based on the 

newer data. At the same time, auto manufacturers generally supported the proposed 

vehicle weight distinction, asserting a higher degree of uncertainty about the emission 

performance of their larger vehicles, especially in the early years of the program and in 

light of simultaneous technology challenges. The newer data clearly show that larger 

vehicles today are generally achieving US06 PM levels very similar to smaller vehicles, 

and well below the proposed standards. We are not finalizing separate US06 standards 

for heavier and lighter vehicles because separate standards are unwarranted based on a 

review of the newer data. However, we believe that the short-term 10 mg/mi standard, as 

well as the temporary in-use vehicle testing standard, will significantly reduce 

manufacturer compliance uncertainties in the early years of the program for all vehicles, 

as discussed above. 

As with the FTP PM standards, manufacturers will comply with the US06 PM 

standards with the same increasing minimum percentage of their vehicles, as shown in 

Table IV.5. Also as with the FTP PM phase-in, we are providing the option for a 

manufacturer to choose to certify 10 percent of its total light-duty vehicle sales in MY 

2017 to the new US06 PM standards, including light-duty vehicles over 6,000 lbs 

GVWR. 

As discussed in Section IV.A.2.c above, for LDVs and LDTs more than 6,000 lbs 

GVWR and MDPVs, EPA is also providing an alternative phase-in of the US06 PM 

standards. 

All of the SFTP/US06 standards are shown in Table IV-4 and Table IV-5. 
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Table IV-4 Tier 3 LDV, LDT, and MDPV SFTP Composite Fleet Average 

Standards

Model Year

2017

a

2018 2019 2020 2021 2022 2023 2024 2025 and 

later

NMOG + NOX

(mg/mi)

103 97 90 83 77 70 63 57 50

CO (g/mi) 4.2 a

a

For LDVs and LDTs above 6,000 lbs GVWR and MDPVs, the NMOG+NOX and CO standards apply 

beginning in MY 2018.

Table IV-5 Summary of LDV, LDT, and MDPV Tier 3 SFTP Standards

Program Element Units

Model Year Notes

2017a2018 2019 2020 2021 2022 2023 2024+

NMOG+NOX Standard

(fleet average)

mg/mi Per declining fleet average for cars and trucks (see Table 

IV-4)

b

PM Standards

Phase-in % 20c20 40 70 100 100 100 100

US06

LDV, LDT, MDPV: 

Certification

mg/mi 10 10

6 6 6 6 6

6 Note d LDV, LDT, MDPV: 

In-Use

10 10 10 10 10

a For LDVs and LDTs above 6,000 lbs GVWR and MDPVs, the standards apply beginning in MY 2018.

b The percent phase-in does not apply to the declining fleet average standards. 

c Manufacturers comply in MY 2017 with 20 percent of their LDV and LDT fleet under 6,000 lbs GVWR, or 

alternatively with 10 percent of their total LDV, LDT, and MDPV fleet. 

d Manufacturers must test 25 percent of each model year’s durability groups, minimum of 2.

c. Enrichment Limitation for Spark-Ignition Engines

To prevent emissions that result from excessive enrichment from auxiliary

emission control devices (AECD) that are substantially present during the SFTP cycles, 

we are finalizing limitations on the magnitude of enrichment that can be commanded, 

including enrichment episodes encountered during in-use operation. During conditions 

where enrichment is demonstrated to be present on the SFTP, the nominal air-to-fuel ratio 
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cannot be richer at any time than the leanest air-to-fuel ratio required to obtain maximum 

torque (lean best torque or LBT). An air-to-fuel ratio of LBT plus a tolerance of 4 

percent additional enrichment will be allowed in actual vehicle testing to protect for any 

in-use variance in the air-to-fuel ratio from the nominal LBT air-to-fuel determination, 

for such reasons as air or fuel distribution differences from production variances or aging. 

LBT is defined as the leanest air-to-fuel ratio required at a speed and load point 

with a fixed spark advance to make peak torque. Specifically, an increase in fuel will not 

result in an increase in torque while maintaining a fixed spark advance. LBT is 

determined by setting the spark advance to a setting that is less than or equal to the spark 

advance required for best torque (MBT) and maintaining that spark advance when 

sweeping the air-to-fuel ratio. This fixed spark advance requirement is intended to 

prevent torque changes related to spark changes masking true LBT. One manufacturer 

commented that there is no universally accepted definition or procedure to determine 

LBT so we should retain the Tier 2 LBT requirements. We believe that the proposed 

definition provides sufficient clarity and will generally agree with most manufacturers’ 

internal definition of LBT. Additionally, we are finalizing the flexibility that 

manufacturers may request approval of an alternative LBT definition for a unique 

technology or control strategy. The Agency may determine that an enrichment amount is 

excessive or not necessary and therefore deem that the approach does not meet the air-tofuel ratio requirements. 

Enrichment required for thermal protection will continue to be allowed upon 

demonstration of necessity to the Agency, based upon temperature limitations of the 

engine or exhaust components. Manufacturers will be required to provide descriptions 

of all components requiring thermal protection, temperature limitations of the 

components, how the enrichment strategy will detect over-temperature conditions and 

correct them, and a justification regarding why the enrichment is the minimum necessary

to protect the specific components. The Agency may determine that the enrichment is 

not justified or is not the minimum necessary based on the use of engineering judgment 

using industry-reported thermal protection requirements.

A manufacturer commented that this requirement to report enrichment 

requirements for component protection for every application is burdensome and 

unnecessary. EPA believes that closer review of off-cycle enrichment by the agency, 

including enrichment for component protection, is necessary to ensure emissions are well 

controlled under all operating conditions. While this requirement may in some cases 

require additional resources at certification, this information has generally been required 

to be maintained by manufactures to support use of enrichment as an auxiliary emission 

control device (AECD) and therefore should be an exercise of reporting existing records 

for most manufacturers. 

The requirements described in this section apply for vehicles certified to any of 

the Tier 3 standards.
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5. Feasibility of the NMOG+NOX and PM Standards

In the proposal, we concluded that all of the Tier 3 emissions standards are 

technologically feasible in the time frame of the program. The technical conclusions we 

reached at that time have been further reinforced by information we received in the public 

comments or has otherwise become available and placed in the docket for this 

rulemaking. After considering the comments received and with additional supporting 

information in Chapter 1 of the RIA, we conclude that the Tier 3 standards are feasible 

and reasonable, considering lead-time provided and expected compliance costs. 

For each of the emission standards, the lead time provided by the program is more 

than sufficient for all manufacturers to comply. First, manufacturers in many cases are 

already adopting complying technologies for reasons other than this rulemaking. For 

example, many of the technologies that manufacturers have begun to develop for model 

years as early as MY 2014 in response to the CARB LEV III FTP and SFTP 

NMOG+NOX standards for the California market will likely represent steps toward 

compliance with this national program. Similarly, manufacturers have been producing 

some limited vehicle offerings since as early as MY 2000 that comply with our final MY 

2025 standards in response to the CARB PZEV requirements. In addition, as described 

above, our program incorporates a number of phase-in provisions that will ease the 

transition to compliance, including time some manufacturers may need to install PM 

testing capability and to ramp up production on a national scale. This feasibility

assessment is based on a variety of complementary technical data, studies, and analyses. 

As described below, these include our analysis of the stringency of the standards as 

compared to current Tier 2 emission levels. We also discuss below our observation that 

manufacturers are currently certifying several vehicle models under the California LEV II 

program that could likely achieve the Tier 3 NMOG+NOX and PM standards or similar 

levels. EPA has assessed the emissions control challenges manufacturers will generally 

face (e.g., cold start NMOG reductions and running (warmed-up) NOX emissions under 

typical and more aggressive driving conditions) and the corresponding technologies that 

we expect to be available to manufacturers to meet these challenges. Our feasibility

assessment accounts for the fact that the Tier 3 program will apply to all types of new 

vehicles, ranging from small cars to large pick-up trucks and MDPVs and representing a 

wide diversity in applications and in specific engine designs. 

It is important to note that our primary assessment of the feasibility of engine and 

emission control technologies is based on the assumption that vehicles will be certified 

on gasoline with a fuel sulfur content of 10 ppm and operated on in-use gasoline with an 

average of 10 ppm sulfur.258 Therefore, our primary assessment does not incorporate the 

degradation of emission control system caused by higher levels of sulfur content, as is 

 

258 Our technology, feasibility, and cost assessments are also consistent with an assumption that 

certification fuel will contain 10 percent ethanol and will have other properties as specified in Section IV.F

below.
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discussed in Section IV.A.6 below and further discussed in the RIA. This assessment 

reinforces the critical role of gasoline sulfur control in making it possible for EPA to 

establish emission standards at these very stringent levels. See Section IV.6 below for a 

full discussion of our current knowledge of the effects of gasoline sulfur on current Tier 2 

vehicle emissions as well as our projections of how we expect that sulfur will affect 

compliance on vehicles with standards in the range of the Tier 3 standards. The 

projections are based on extensive EPA testing of Tier 2 vehicles as well as targeted 

evaluation of passenger cars and heavier trucks performing at or near the Tier 3 Bin 30 

(30 mg/mi NMOG+NOX) including manufacturer supplied data of a prototype Tier 3 

light-duty truck as discussed in Section IV.6. 

Since there are multiple aspects to the Tier 3 program, it is necessary to consider 

technical feasibility in light of the different program requirements and their interactions 

with each other. In many cases, manufacturers will be able to address more than one 

requirement with the same general technological approach (e.g., faster catalyst light-off 

can improve both FTP NMOG+NOX and PM emissions). At the same time, the 

feasibility assessment must consider that different technologies may be needed on 

different types of vehicle applications (e.g., cars versus trucks) and must consider the 

relative effectiveness of these technologies in reducing emissions for the full useful life 

of the vehicle while operating on expected in-use fuel. For example, certain smaller 

vehicles with correspondingly small engines may be less challenged to meet FTP 

standards than larger vehicles with larger engines. Conversely, these smaller vehicles 

may have more difficulty meeting the more aggressive SFTP requirements than vehicles 

with larger and more powerful engines. Additionally, the ability to meet the SFTP 

emission requirements can also be impacted by the path taken to meet the FTP 

requirements (e.g., larger volume catalysts for US06 emissions control vs. smaller 

catalysts for improved FTP cold-start emissions control). Throughout the following 

discussion, we address how these factors, individually and in interaction with each other, 

affect the feasibility of the final program. 

a. FTP NMOG+NOX Standards

The Tier 3 emission requirements include stringent NMOG+NOX standards on the 

FTP that will require new vehicle hardware in order to achieve the 30 mg/mi fleet 

average level in MY 2025. The type of new hardware that will be required will vary

depending on the specific application and emission challenges. Smaller vehicles with 

corresponding smaller engines will generally need less new hardware while larger 

vehicles may need additional hardware and improvements beyond what will be needed 

for the smaller vehicles. While some vehicles, especially larger light trucks, may face 

higher costs in meeting the standards, it is important to remember that not every vehicle 

needs to meet the standard. The program has been structured to provide higher emission 

standard “bins” (see Table IV-1 above) to which manufacturers may certify more 

challenged vehicles, so long as these vehicles are offset with vehicles certified in lower 

emission bins such that the fleet-wide average meets the standards. We believe that the 

availability of the less-stringent bins will allow for the balancing of feasibility and cost 
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considerations of compliance strategies for all vehicles. In the Tier 2 program, 

manufacturers took advantage of this flexibility, especially in the early years of the 

program. Then, as technologies improved and/or became less expensive and the need for 

averaging diminished, manufacturers began certifying all or most of their fleets to the 

average bin (Tier 2 Bin 5). We anticipate that manufacturers will follow a similar trend 

with the Tier 3 standards, relying on fleet averaging more significantly in the transitional 

years but certifying increasing numbers of their vehicles to the final fleet average 

standard of 30 mg/mi in the later years of the program. 

In order to assess the technical feasibility of a 30 mg/mi NMOG+NOX national 

fleet average FTP standard, EPA conducted two supporting analyses. The initial analyses 

performed were of the current Tier 2 and LEV II fleets. This provided a baseline for the 

current federal fleet emissions performance, as well as the emissions performance of the 

California LEV II fleet. The second consideration was a modal analysis of typical 

vehicle emissions under certain operating conditions. In this way EPA determined the 

specific emissions performance challenges that vehicle manufacturers will face in 

meeting the lower fleet average emission standards. Each of these considerations is

described in greater detail below.

The current Tier 2 federal fleet is certified to an average of Tier 2 Bin 5, 

equivalent to 160 mg/mi NMOG+NOX.

259

 As an example, for MY 2009 when the Tier 2 

program was fully implemented across all vehicle types, 92 percent of LDVs and LDT1s 

were certified to Tier 2 Bin 5 and 91 percent of LDT2s through LDT4s were certified to 

Tier 2 Bin 5. This trend has generally continued through MY 2013 as the most recent 

certification results indicate that manufacturers are continuing to certify primarily to Tier 

2 Bin 5 standards for the federal fleet however there has been a shift to more 

certifications using the cleaner bins as discussed in the RIA. This is not an unexpected 

result as there is no motivation prior to implementation of the Tier 3 rulemaking for 

vehicle manufacturers to produce a federal fleet that over-complies with respect to the 

existing Tier 2 standards. By comparison, in the California fleet where compliance with 

the declining fleet average NMOG requirement and the “PZEV” program requires 

manufacturers to certify vehicles to cleaner levels, only 30 percent of the LDVs and 

LDT1s are certified to Tier 2 Bin 5 and 60 percent are certified to cleaner bins such as 

Tier 2 Bin 3 and 4. The situation regarding the truck fleet in California is similarly

stratified, with 37 percent of the LDT2s through LDT4s being certified to Tier 2 Bin 5 

and 55 percent being certified to the cleaner Tier 2 Bin 3 and 4. In many cases identical 

vehicles are being certified to a lower standard in California and a higher standard 

federally simply because there is no incentive to over perform to the federal standards. 

We note that vehicles certified to a lower standard in California are operated on gasoline 

with an average sulfur content of 10 ppm and thereby are able to maintain their emissions 

 

259 The Tier 2 program does not combine NMOG and NOX emissions into one fleet-average standard. The 

fleet-average standard in that program is for NOX emissions alone. The NOX fleet-average requirement of 

.07 gm/mi is the same level as the Bin 5 NOX standard.
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performance in-use. Based on these patterns of federal and California certification, EPA 

believes that much of the existing Tier 2 fleet could currently be certified to a lower 

federal fleet average immediately, with no significant feasibility concerns, if lower sulfur 

gasoline were made available nationwide.

Regardless of the Tier 2 bin standards at which manufacturers choose to certify

their vehicles, actual measured emissions performance of these vehicles is typically well 

below the numerical standards. This difference is referred to as “compliance margin” 

and is a result of manufacturers’ efforts to address all the sources of variability, 

including: 

 Test-to-test variability (within one test site and lab-to-lab)

 Build variation expectations

 Manufacturing tolerances and stack-up

 Vehicle operation (for example: driving habits, ambient temperature, etc.)

 Fuel composition

 The effects of fuel sulfur on exhaust catalysts and oxygen sensors 

 The effects of other fuel components, including ethanol and gasoline additives

 Oil consumption

 The impact of oil additives and oil ash on exhaust catalysts and oxygen 

sensors

For MY 2009 thru MY 2013, the compliance margin for a Tier 2 Bin 5 vehicle 

averaged approximately 60 percent. In other words, actual vehicle emissions 

performance was on average about 40 percent of a 160 mg/mi NMOG+NOX standard, or 

about 64 mg/mi. By comparison, for California-certified vehicles, the average Super 

Ultra Low Emission Vehicle (SULEV) compliance margin was somewhat less for the 

more stringent standards, approximately 50 percent. We believe that the recent 

California experience is a likely indicator of compliance margins that manufacturers will 

design for in order to comply with the Tier 3 FTP standards. Thus, a typical Tier 2 Bin 5 

vehicle, performing at 40 percent of the current standard (i.e., at about 64 mg/mi) will 

need improvements sufficient to reach about 15 mg/mi (50 percent of a 30 mg/mi 

standard). 

To understand how the several currently-used technologies described below could 

be used by manufacturers to reach the stringent Tier 3-NMOG+NOX standards, it is 

helpful to consider emissions formation in common modes of operation for gasoline 
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engines, or modal analysis.260 The primary challenge faced by manufacturers for 

producing Tier 3 compliant light-duty gasoline vehicle powertrains will be keeping 

warmed-up running emissions at effectively zero emissions levels while reducing the 

emissions during cold-start operation which, based on modal analysis of a gasolinepowered vehicle being operated on the FTP cycle, occurs during about the first 50 

seconds after engine start. Thus, we believe that to comply with the Tier 3 FTP 

standards, manufacturers will focus on effective control of these cold-start emissions 

while maintaining zero running emissions; this is only possible when sulfur levels in the 

fuel do not degrade catalyst performance. As discussed below, light-duty manufacturers 

are already applying several technologies capable of significant reductions in these cold 

start emissions to vehicles currently on the road. 

During the analysis of current vehicles certified to the cleanest emission levels 

(Tier 2 Bin 2 and LEV II SULEV) it was noted that no large pick-ups equipped with their 

application specific engines were performing at the 30 mg/mi NMOG+NOX level. We 

believe that these applications may be the most challenging due to the fact that the design 

criteria required to provide the utility aspect may have direct impact on their ability to 

implement some of the technologies described in section IV.A.5.d below. Since these 

vehicles represent a substantial and important part of the light- duty fleet, EPA performed 

a technical feasibility study directly targeting this class of vehicles. 

In order to assess the technical feasibility of a 30 mg/mi FTP NMOG+NOX 

standard, EPA purchased a 2011 Chevrolet Silverado heavy-light-duty (LDT4) pickup 

truck with a developmental goal of modifying the truck to achieve exhaust emission 

levels in compliance with the Tier 3 Bin 30 emissions standards including a reasonable 

compliance margin. The truck was equipped with a 5.3L V8 with General Motors’ 

“Active Fuel Management” cylinder deactivation system. This particular truck was 

chosen as an example of a Tier 3 prototype in part because cylinder deactivation is a key

technology for light-truck compliance with future GHG standards and in part because it 

achieved very low emissions in the OEM, Tier 2-compliant configuration (certified to 

Tier 2 Bin 4). A prototype exhaust system was obtained from MECA consisting of highcell-density (900 cpsi) thin-wall (2.5 mil), high-PGM, close-coupled Pd-Rh catalysts with 

an additional under-body Pd-Rh catalyst. The total catalyst volume was approximately

116 in3 with a specific PGM loading of 125 g/ft3and approximate loading ratio of 0:80:5 

(Pt:Pd:Rh). Third-party (non-OEM) EMS calibration tools were used to modify the 

powertrain calibration in an effort to improve catalyst light-off performance. The final 

test configuration used approximately 4 degrees of timing retard and approximately 200 

rpm higher idle speed relative to the OEM configuration during and immediately

following cold-start. The exhaust catalyst system and HEGO sensors were bench aged to

an equivalent 150,000 miles using standard EPA accelerated catalyst bench-aging 

 

260 A modal analysis provides a second-by-second view of the total amount of emissions over the entire 

cycle being considered.
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procedures. The truck was tested on California LEV III E10 certification fuel at 9 ppm 

gasoline sulfur levels.

The EPA Tier 3 prototype Silverado achieved NMOG+NOx emissions of 18 mg/mi on 

the 9 ppm S fuel. The NMOG+NOx emissions were approximately 60% of the Bin 30 

standard and thus are consistent with meeting the Tier 3 Bin 30 exhaust emissions 

standard with a moderate compliance margin. The technologies used on the prototype 

Silverado to achieve these emission levels are common approaches used today on smaller 

vehicles. They do not compromise any of the design utility of this vehicle class and are 

some of the same approaches we expect manufacturers to use to meet the Tier 3 Bin 30 

exhaust emissions standards.

b. SFTP NMOG+NOX Standards

The increase in the stringency of the SFTP NMOG+NOX standards, specifically

across the US06 cycle, will generally only require additional focus on fuel control of the 

engines and diligent implementation of new technologies that manufacturers are already 

introducing or are likely to introduce in response to the current and 2017 LD GHG 

emission standards. These include downsized gasoline direct injection (GDI) and 

turbocharged engines, which may also include improvements to the engine and emission 

control hardware to tolerate higher combustion and exhaust temperatures expected in 

these future GHG-oriented engine designs when under higher loads. The upgraded 

materials or components will enable manufacturers to rely less on fuel enrichment during 

high-speed/high-load operation to protect components from overheating. This fuel 

enrichment is currently the source of elevated VOC, NOX, and PM emissions seen in a 

subset of the current Tier 2 fleet.

With respect to enrichment, the primary method available to manufacturers to 

protect the catalyst and other exhaust components from over-temperature conditions has 

been changes to the fuel/air mixture by increasing the fuel fraction, but this is no longer 

the only tool available to manufacturers for this purpose. With the application of 

electronic throttle controls, variable valve timing, exhaust gas recirculation and other 

exhaust temperature influencing technologies on nearly every light-duty vehicle, the 

manufacturer has the ability to systematically control the operation and combustion 

processes of the engine to minimize or altogether avoid areas and modes of operation 

where thermal issues can occur. While some of these solutions could in some cases result

in a small and temporary reduction in vehicle performance (absolute power levels), we 

believe that it could be an effective way to reduce NMOG+NOX emissions over the SFTP 

test. 

Additionally, some components, especially catalysts, can experience accelerated 

thermal deterioration that occurs when operating at higher temperatures for more time 

than expected under normal operation (e.g., trailer towing, mountain grades). Some 

upgrades of existing vehicle emission control technology, like catalyst substrates and 
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washcoats may be required to limit thermal deterioration and ensure vehicle emissions 

compliance throughout the useful life of the vehicle. 

In order to assess the technical feasibility of a 50 mg/mi NMOG+NOX national 

fleet average SFTP standard, EPA conducted an analysis of SFTP levels of Tier 2 and 

LEV II vehicles. The analysis was performed on the US06 results from current Tier 2 and 

LEV II vehicles tested in the in-use verification program (IUVP) by manufacturers and 

submitted to EPA. This analysis provided a baseline for the current Tier 2 and LEV II 

fleet emissions performance, as well as the SFTP emissions performance capability of the 

cleanest vehicles meeting the Tier 3 FTP standards. The analysis concluded that most 

vehicles in the IUVP testing program are already capable of meeting the composite SFTP 

standard of 50 mg/mi when the Tier 3 FTP standard levels are factored into the composite 

calculation. With the technological improvements already underway as discussed above, 

we believe all MY 2017 and later vehicles will be able to comply with the SFTP 

standards, either directly or through the flexibility of the averaging, banking and trading 

program. For further information on the analysis see Chapter 1 of the RIA.

c. FTP and SFTP PM Standards

As described above for NMOG+NOX over the SFTP, the increase in the 

stringency of the FTP and SFTP PM standards will generally also only require additional 

focus on fuel control of the engines and attention to PM emissions during the 

implementation of new technologies like gasoline direct injection (GDI) and 

turbocharged engines. Some upgrades of existing vehicle emission control technology

may be required to ensure vehicle emissions performance is maintained throughout the 

useful life of the vehicle. These upgrades may include improvements to the engine to 

control wear that could result in increased PM from oil consumption and selection of GDI 

systems that will be capable of continuing to perform optimally even as the systems age. 

We based our conclusions about the ability of manufacturers to meet the PM 

standards largely on the PM performance of the existing fleet, both on the FTP and SFTP. 

In the case of FTP testing of current vehicles, data on both low and high mileage lightduty vehicles demonstrate that the majority of vehicles are currently achieving levels at 

or below the Tier 3 FTP PM standards. 

The testing results can be found in Chapter 1 of the RIA. A small number of 

vehicles are at or just over the Tier 3 FTP PM standard at low mileage and could require 

calibration changes and/or catalyst changes to meet the new standards. It is our 

expectation that the same calibration and catalyst changes required to address NMOG 

will also provide the necessary PM control. Vehicles that currently have higher PM 

emissions over the FTP or SFTP at higher mileages will likely be required to control oil 

consumption and combustion chamber deposits. 

We also analyzed PM test data results on the US06 test cycle from Tier 2 

vehicles. The data show that many vehicles are already at or below the Tier 3 standards 
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on the US06 test cycle. Vehicles that have high PM emission rates on the US06 will 

likely need to control enrichment and oil consumption, particularly later in life. As 

described above for SFTP NMOG+NOX control, enrichment can be more accurately 

managed through available electronic engine controls. The strategies for reducing oil 

consumption are similar to those described above for controlling oil consumption on the 

FTP. However, given the higher engine speeds experienced on the US06 and the increase 

in oil consumption that can accompany this kind of operation, manufacturers will most 

likely focus on oil sources stemming from the piston to cylinder interface and positive 

crankcase ventilation (PCV). 

Manufacturers have informed us that they have already reduced or are planning to 

reduce the oil consumption of their engines by improved sealing of the paths of oil into 

the combustion chamber and improved piston-to-cylinder interfaces. Auto manufacturers 

have stated that they are already taking or considering these actions to address issues of 

customer satisfaction and cost of ownership. In addition, many vehicle manufacturers 

acknowledge the relationship between combustion chamber deposits and PM formation 

and are actively pursuing design changes to mitigate fuel impingement within the 

combustion chamber and its commensurate PM effects. Both types of controls are being 

widely applied by manufacturers today.

d. Technologies Manufacturers are Likely to Apply

Most of the technologies expected to be applied to light-duty vehicles to meet the 

stringent Tier 3 standards will address the emissions control system’s ability to reduce 

emission during cold start while maintaining zero or near zero running emissions. The 

effectiveness of current vehicle emissions control systems at reducing cold start 

emissions depends in large part on the time it takes for the catalyst to light off, which is 

typically defined as the catalyst reaching a temperature of 250 °C. In order to improve 

catalyst light-off, we expect that manufacturers will add technologies that provide heat 

from combustion more readily to the catalyst or improve the catalyst efficiency at lower 

temperatures. These technologies include calibration changes, catalyst platinum group 

metals (PGM) loading and strategy, thermal management, close-coupled catalysts, and 

secondary air injection, all which generally improve emission performance of all 

pollutants. In some cases where the catalyst light-off and efficiency are not enough to 

address the cold start NMOG emissions, hydrocarbon adsorbers may be applied to trap 

hydrocarbons until such time that the catalyst is lit off. Note that with the exception of 

hydrocarbon adsorbers each of these technologies addresses NMOG, NOX, and PM 

performance. The technologies are described in greater detail below. Additional 

information on these technologies can also be found in Chapter 1 of the RIA.

 Engine Control Calibration Changes – These include changes to retard spark 

and/or adjust air/fuel mixtures such that more combustion heat is created 

during the cold start. Control changes may include injection strategies in GDI 

applications, unique cold-start variable valve timing and lift, and other 
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available engine parameters. Engine calibration changes can affect NMOG, 

NOX and PM emissions.

 Catalyst PGM Loading – Additional PGM loading, increased loading of other 

active materials, and improved dispersion of PGM and other active materials 

in the catalyst provide a greater number of sites available to catalyze 

emissions and addresses NMOG, NOX and PM emissions. Catalyst PGM 

loading, when implemented in conjunction with low sulfur gasoline, will 

effectively eliminate NOX emissions under warmed-up conditions.

 Thermal Management – This category of technologies includes all design 

attributes meant to conduct the combustion heat into the catalyst with minimal 

cooling. This includes insulating the exhaust piping between the engine and 

the catalyst, reducing the wetted area of the exhaust path, reducing the thermal 

mass of the exhaust system, and/or using close-coupled catalysts (i.e., the 

catalysts are packaged as close as possible to the engine’s cylinder head to 

mitigate the cooling effects of longer exhaust piping). Thermal management 

technologies primarily address NMOG emissions, but also affect NOX and 

PM emissions.

 Secondary Air Injection – By injecting air directly into the exhaust stream, 

close to the exhaust valve, combustion can be maintained within the exhaust, 

creating additional heat by which to increase the catalyst temperature. The 

air/fuel mixture must be adjusted to provide a richer exhaust gas for the 

secondary air to be effective. There can be a NOx emissions disbenefit to use 

of secondary air injection since it can impact the ability of oxygen storage 

components (OSC) within the catalyst to take up excess oxygen as necessary 

to promote NOx reduction reactions immediately following cold start 

conditions.

 Hydrocarbon Adsorber – Traps hydrocarbons during a cold start until the 

catalyst lights off, and then releases the hydrocarbons to be converted by the 

catalyst.

 Gasoline Sulfur – The relative effectiveness for NMOG and NOX control of 

the exhaust-catalyst related technologies is constrained by gasoline fuel sulfur 

levels. Thus, reduced sulfur in gasoline is an enabling technology to achieve 

the standards and maintain this performance during in-use operation. We 

discuss the relationship between gasoline sulfur and emissions in greater detail 

in Section IV.6 below and in the RIA. 

Several commenters indicated that large light-duty trucks (e.g., pickups and fullsize sport utility vehicles (SUVs) in the LDT3 and LDT4 categories) will be the most 

challenging light-duty vehicles to bring into compliance with the Tier 3 NMOG+NOX

standards at the 30 mg/mi corporate average emissions level. A similar challenge was 
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addressed when large light-duty trucks were brought into compliance with the Tier 2 

standards over the past decade. Figure IV-1 provides a graphical representation of the 

effectiveness of Tier 3 technologies for large light-duty truck applications. A compliance 

margin is shown in both cases. Note that the graphical representation of the effectiveness 

of catalyst technologies on NOX and NMOG when going from Tier 2 to Tier 3 levels also 

includes a reduction in gasoline sulfur levels from 30 ppm to 10 ppm.
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0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

150

160

170

180

Tier 2 Bin 5 LDT3/4

w/30 ppm S Gasoline

Tier 3 LDT3/4

w/10 ppm S Gasoline

N

M

O

G+N

Ox Emissoins (mg/mi)@ 120,000 miles

NMOG+NOx Emissons of Tier 3 LD3/T4

NMOG+NOx Emissions of Tier 2 Bin 5 LDT3/4 

60% 

Compliance

Margin

20-40% Compliance Margin

Tier 2 Bin 5 NMOG+NOx Standard

Tier 3 NMOG+NOx Standard

Passive HC Adsorber

Thermal Management

Secondary 

Air Injection

67% Emissions 

Reduction

Catalyst 

PGM Loading

Figure IV-1: Contribution of Tier 3 Technologies to Large Light-Duty Truck 

Compliance261

 

261 The technologies and levels of control in this figure are based on a combination of confidential business 

information submitted by auto manufacturers and suppliers, public data, and EPA staff engineering 

judgment.
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6. Impact of Gasoline Sulfur Control on the Effectiveness of the Vehicle 

Emission Standards

In this section, we discuss the impact of gasoline sulfur control on the feasibility

of the Tier 3 vehicle emissions standards and on the exhaust emissions of the existing inuse vehicle fleet. Section IV.A.6.a describes the chemistry and physics of the impacts of 

gasoline sulfur compounds on exhaust catalysts. Sections IV.A.6.b, c and d summarize 

research on the impacts of gasoline sulfur on vehicles utilizing various degrees of 

emission control technology, with Section IV.A.6.b summarizing historical studies on the 

impact of gasoline sulfur on vehicle emissions, Section IV.A.6.c describing impacts on 

Tier 2 vehicles and the existing light-duty vehicle fleet, and Section IV.A.6.d describing 

impacts on vehicles using technology consistent with what we expect to see in the future 

Tier 3 vehicle fleet. Section IV.A.6.e provides EPA’s assessment of the level of gasoline 

sulfur control necessary for light-duty vehicles to comply with Tier 3 exhaust emission 

standards. 

EPA’s primary findings are:

• Reducing gasoline sulfur content to a 10 ppm average will provide immediate 

and significant exhaust emissions reductions to the current, in-use fleet of 

light-duty vehicles.

• Reducing gasoline sulfur content to an average of 10 ppm will enable vehicle 

manufacturers to certify their entire product lines of new light-duty vehicles to 

the final Tier 3 Bin 30 fleet average standards. Without such sulfur control it 

would not be possible for vehicle manufacturers to reduce emissions 

sufficiently below Tier 2 levels to meet the new Tier 3 standards because it 

would require offsetting significantly higher exhaust emissions resulting from 

the higher sulfur levels. EPA has not identified any existing or developing 

technologies that would compensate for or offset the higher exhaust emissions 

resulting from higher fuel sulfur levels. 

a. Gasoline Sulfur Impacts on Exhaust Catalysts 

Modern three-way catalytic exhaust systems utilize platinum group metals 

(PGM), metal oxides and other active materials to selectively oxidize organic compounds 

and carbon monoxide in the exhaust gases. These systems simultaneously reduce NOx 

when air-to-fuel ratio control operates in a condition of relatively low amplitude/high 

frequency oscillation about the stoichiometric point. Sulfur is a well-known catalyst 

poison. There is a large body of work demonstrating sulfur inhibition of the emissions 

control performance of PGM three-way exhaust catalyst 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 123 of 1039

systems.262,263,264,265,266,267,268,269,270,271 The nature of sulfur interactions with washcoat 

materials, active catalytic materials and catalyst substrates is complex and varies with 

catalyst composition, exhaust gas composition and exhaust temperature. The variation of 

these interactions with exhaust gas composition and temperature means that the 

operational history of a vehicle is an important factor; continuous light-load operation, 

throttle tip-in events and enrichment under high-load conditions can all impact sulfur 

interactions with the catalyst. 

Sulfur from gasoline is oxidized during spark-ignition engine combustion 

primarily to SO2 and, to a much lesser extent, SO3

-2

. Sulfur oxides selectively chemically 

bind (chemisorb) with, and in some cases react with, active sites and coating materials 

within the catalyst, thus inhibiting the intended catalytic reactions. Sulfur oxides inhibit 

pollutant catalysis chiefly by selective poisoning of active PGM, ceria sites, and the 

alumina washcoating material (see Figure IV-2).272 The amount of sulfur retained by an 

exhaust catalyst system is primarily a function of the concentration of sulfur oxides in the 

incoming exhaust gases, air-to-fuel ratio feedback and control by the engine management 

system, the operating temperature of the catalyst and the active materials and coatings 

used within the catalyst. 

In their supplemental comments to the Tier 3 proposal, API criticized the use of 

emissions data generated using gasoline with sulfur content outside of the range of 10 

ppm to 30 ppm within EPA and other analyses of the impacts of gasoline sulfur on 

 

262 Beck, D.D., Sommers, J.W., DiMaggio, C.L. (1994). Impact of sulfur on model palladium-only catalysts 

under simulated three-way operation. Applied Catalysis B: Environmental 3, 205-227.

263 Beck, D.D., Sommers, J.W. (1995). Impact of sulfur on the performance of vehicle aged palladium 

monoliths.” Applied Catalysis B: Environmental 6, 185-200.

264 Beck, D.D., Sommers, J.W., DiMaggio, C.I. (1997). Axial characterization of oxygen storage capacity 

in close coupled lightoff and underfloor catalytic converters and impact of sulfur. Applied Catalysis B: 

Environmental 11, 273-290.

265 Waqif, M., Bazin, P., Saur, O. Lavalley, J.C., Blanchard, G., Touret, O. (1997), Study of ceria sulfation. 

Applied Catalysis B: Environmental 11, 193-205.

266 Bazin, P., Saur, O. Lavalley, J.C., Blanchard, G., Visciglio, V., Touret, O. (1997). “Influence of 

platinum on ceria sulfation.” Applied Catalysis B: Environmental 13, 265-274.

267 Takei, Y., Kungasa, Y., Okada, M., Tanaka, T. Fujimoto, Y. (2000). Fuel Property Requirement for 

Advanced Technology Engines. SAE Technical Paper 2000-01-2019.

268 Takei, Y., Kungasa, Y., Okada, M., Tanaka, T. Fujimoto, Y. (2001). “Fuel properties for advanced 

engines.” Automotive Engineering International 109 12, 117-120.

269 Kubsh, J.E., Anthony, J.W. (2007). The Potential for Achieving Low Hydrocarbon and NOX Exhaust 

Emissions from Large Light-Duty Gasoline Vehicles. SAE Technical Paper 2007-01-1261.

270 Shen, Y., Shuai, S., Wang, J. Xiao, J. (2008). Effects of Gasoline Fuel Properties on Engine 

Performance. SAE Technical Paper 2008-01-0628.

271 Ball, D., Clark, D., Moser, D. (2011). Effects of Fuel Sulfur on FTP NOX Emissions from a PZEV 4 

Cylinder Application. SAE Technical Paper 2011-01-0300.

272 Heck, R.M., Farrauto, R.J. (2002). Chapter 5: Catalyst Deactivation in Catalytic Air Pollution Control, 

2

nd Edition. John Wiley and Sons, Inc.
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 124 of 1039

exhaust emissions from current in-use (Tier 2) and future (Tier 3) light-duty vehicles. 

Specific examples include: 

 Comparisons of exhaust emissions at 5 ppm and 28 ppm gasoline sulfur 

levels within the recent EPA study of emissions from Tier 2 vehicles273

 Comparison of exhaust emissions of a SULEV vehicle at 8 ppm and 33 

ppm gasoline sulfur levels within the Takei et al. study274

 Comparison of exhaust emissions of a PZEV vehicle at 3 ppm and 33 ppm 

gasoline sulfur levels within the Ball et al. study.

275

The relationship between changes in gasoline sulfur content and NOx, HC, 

NMHC and NMOG emissions is typically linear. The linearity of sulfur impacts on NOx, 

NMHC and NMOG emissions is supported by past studies with multiple fuel sulfur 

levels all of which compare gasoline with differing sulfur levels that are below 

approximately 100 ppm (e.g., CRC E-60 and 2001 AAM/AIAM programs as well as 

comments on this rulemaking submitted by MECA).276,277,278 An assumption of linearity 

of the effect of gasoline sulfur level on catalyst efficiency between any two test fuels 

with differing sulfur levels is reasonable given that the mass flow rate of sulfur in exhaust 

gas changes in proportion to its concentration in the fuel, and that the chemistry of 

adsorption of sulfur on the active catalyst sites is an approximately-first-order 

chemisorption until all active sites within a catalyst reach an equilibrium state relative to 

further input of sulfur compounds. The relative linearity of the effect of gasoline sulfur 

level on NMOG and NOx emissions allows exhaust emissions results generated within 

EPA and other studies of gasoline sulfur at levels immediately above or below either 10 

ppm or 30 ppm to be normalized to either 10 ppm sulfur (Tier 3 gasoline) or to 30 ppm 

sulfur (Tier 2 gasoline, which are used in the analysis of the impacts of the Tier 3 

gasoline standards on existing in-use vehicles and future Tier 3 vehicles.

 

273

 The Effects of Ultra-Low Sulfur Gasoline on Emissions from Tier 2 Vehicles in the In-Use Fleet, EPA420-R-14-002.

274 Takei, Y., Kungasa, Y., Okada, M., Tanaka, T. Fujimoto, Y. (2000). Fuel Property Requirement for 

Advanced Technology Engines. SAE Technical Paper 2000-01-2019. 

275 Ball, D., Clark, D., Moser, D. (2011). Effects of Fuel Sulfur on FTP NOX Emissions from a PZEV 4 

Cylinder Application. SAE Technical Paper 2011-01-0300. 

276 Coordinating Research Council. 2003. “The Effect of Fuel Sulfur on NH3 and Other Emissions from 

2000-2001 Model Year Vehicles.” CRC Project No. E-60 Final Report. Accessed on the Internet on 

12/4/2013 at the following URL: http://www.crcao.com/reports/recentstudies2003/E60%20Final%20Report.pdf. 

277 Alliance of Automobile Manufacturers. 2001. “AAM-AIAM Industry Low Sulfur Test Program.”

278 Manufacturers of Emission Controls Association. 2013. “The Impact of Gasoline Fuel Sulfur on 

Catalytic Emission Control Systems.”
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 125 of 1039

In their supplemental comments to the Tier 3 proposal, API also commented that 

EPA did not show the sulfur impact on exhaust emissions at intermediate sulfur levels 

between 10 ppm and 30 ppm. In response, based on the relative linearity of the effect of 

gasoline sulfur level on NMOG and NOx emissions allowing exhaust emissions to be 

estimated for gasoline sulfur levels between 10 and 30 ppm, data in EPA’s analysis 

shows increases NMOG+NOx emissions (as fuel sulfur increases) that become more 

severe (i.e., higher percentage increase in NMOG+NOx emissions) for vehicles with 

extremely low279 exhaust emission (SULEV, PZEV, LEV III, Tier 3) as described in 

further detail in Sections IV.A.6.d and e.

100 Å

Catalytic Site Deactivated by Sulfur Poisoning

Active Catalytic Site

Alumina Washcoat

Monolith Substrate

Figure IV-2 Functional schematic showing selective poisoning of active catalytic 

sites by sulfur compounds. Adapted from Heck and Farrauto 2002.280

 

279 Vehicles that meet the cleanest emission standards by demonstrate very low cold start NMOG and NOx 

emissions and zero or near-zero running NMOG and NOx emissions.

280 Heck, R.M., Farrauto, R.J. (2002). Chapter 5: Catalyst Deactivation in Catalytic Air Pollution Control, 

2

nd Edition. John Wiley and Sons, Inc.
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 126 of 1039

Selective sulfur poisoning of platinum (Pt) and rhodium (Rh) is primarily from 

surface-layer chemisorption. Sulfur poisoning of palladium (Pd) and ceria appears to be 

via chemisorption combined with formation of more stable metallic sulfur compounds, 

e.g. PdS and Ce2O2S, present in both surface and bulk form (i.e., below the surface 

layer).281,282,283,284 Ceria, zirconia and other oxygen storage components (OSC) play an 

important role that is crucial to NOX reduction over Rh as the engine air-to-fuel ratio 

oscillates about the stoichiometric closed-loop control point. 285 Ceria sulfation interferes 

with OSC functionality within the catalyst and thus can have a detrimental impact on the 

catalyst’s ability to effectively reduce NOx emissions. Water-gas-shift reactions are 

important for NOX reduction over catalysts combining Pd and ceria. This reaction can be 

blocked by sulfur poisoning and may be responsible for observations of reduced NOX

activity over Pd/ceria catalysts even with exposure to fairly low levels of sulfur 

(equivalent to 15 ppm in gasoline).286, 287 Pd is also of increased importance for meeting 

Tier 3 standards due to its unique application in the close-coupled-catalyst location 

required for vehicles certifying to very stringent emission standards. Close-coupling 

means that the exhaust catalyst is moved as close as possible to the engine’s exhaust ports 

within the packaging constraints of an engine compartment. This ensures that the catalyst 

reaches its minimal operational, or “light-off”, temperature as quickly as possible after 

the vehicle is started. It also means, however, that the exhaust catalyst(s) in the closecoupled location(s) are subject to higher exhaust temperatures during fully-warmed up 

operation. Pd is required in closed-coupled catalysts due to its resistance to hightemperature thermal sintering thereby maintaining sufficient durability of the emissions 

control system over the useful life of a vehicle. Sulfur removal from Pd requires rich 

operation at higher temperatures than required for sulfur removal from other PGM 

catalysts.287

In addition to its interaction with catalyst materials, sulfur can also react with the 

wash-coating itself to form alumina sulfate, which in turn can block coating pores and 

reduce gaseous diffusion to active materials below the coating surface (see Figure 

 

281 Luo, T. Gorte, R.J. (2003). A Mechanistic Study of Sulfur Poisoning of the Water-Gas-Shift Reaction 

Over Pd/Ceria.” Catalysis Letters, 85, Issues 3-4, pg. 139-146.

282 Li-Dun, A., Quan, D.Y. (1990). “Mechanism of sulfur poisoning of supported Pd(Pt)/Al2O3 catalysts for 

H2-O2 reaction.” Applied Catalysis 61, Issue 1, pg. 219-234.

283 Waqif, M., Bazin, P., Saur, O. Lavalley, J.C., Blanchard, G., Touret, O. “Study of ceria sulfation.” 

Applied Catalysis B: Environmental 11 (1997) 193-205.

284 Bazin, P., Saur, O. Lavalley, J.C., Blanchard, G., Visciglio, V., Touret, O. “Influence of platinum on 

ceria sulfation.” Applied Catalysis B: Environmental 13 (1997) 265-274.

285 Heck, R.M., Farrauto, R.J. (2002). Chapter 6: Automotive Catalyst in Catalytic Air Pollution Control, 

2

nd Edition. John Wiley and Sons, Inc...

286 Luo, T. Gorte, R.J. (2003) A Mechanistic Study of Sulfur Poisoning of the Water-Gas-Shift Reaction 

Over Pd/Ceria. Catalysis Letters, 85, Issues 3-4, pg. 139-146.

287 Beck, D.D., Sommers, J.W. (1995) Impact of sulfur on the performance of vehicle aged palladium 

monoliths. Applied Catalysis B: Environmental 6, 185-200.
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 127 of 1039

IV-2).288 This may be a significant mechanism for the observed storage of sulfur 

compounds at light and moderate load operation with subsequent, rapid release as sulfate 

particulate matter emissions when high-load, high-temperature conditions are 

encountered.289

Operating the catalyst at a sufficiently high temperature under net reducing 

conditions (e.g., air-to-fuel equivalence that is net fuel-rich of stoichiometry) can 

effectively release the sulfur oxides from catalyst components. Thus, regular operation at 

sufficiently high temperatures at net fuel-rich air-to-fuel ratios can minimize the effects 

of fuel sulfur levels on catalyst active materials and catalyst efficiency; however, it 

cannot completely eliminate the effects of sulfur poisoning. In current vehicles, 

desulfurization conditions occur typically at high loads when there is a degree of 

commanded enrichment (i.e., fuel enrichment commanded by the engine management 

system primarily for protection of engine and/or exhaust system components). A study of 

Tier 2 vehicles in the in-use fleet recently completed by EPA290 shows that emission 

levels immediately following high speed/load operation is still a function of fuel sulfur 

level for the gasoline used following desulfurization. If a vehicle operates on gasoline 

with less than 10 ppm sulfur, exhaust emissions stabilize over repeat FTP tests at 

emissions near those of the first FTP that follows the high speed/load operation and 

catalyst desulfurization. If the vehicle continues to operate on higher sulfur gasoline 

following desulfurization, exhaust emissions creep upward until a new equilibrium 

exhaust emissions level is established. This suggests that lower fuel sulfur levels achieve 

emission benefits unachievable by catalyst desulfurization procedures alone. Continued 

operation on gasoline with a 10 ppm average sulfur content or lower is necessary after 

catalyst desulfurization in order to achieve emissions reductions with the current in-use 

fleet.291 Furthermore, regular operation at the high exhaust temperatures and rich air-tofuel ratios necessary for catalyst desulfurization is not desirable and may not be possible 

for future Tier 3 vehicles for several reasons: 

 Thermal sintering and resultant catalyst degradation: The temperatures 

necessary to release sulfur oxides are high enough to lead to thermal 

degradation of the catalyst over time via thermal sintering of active 

materials. Sintering reduces the surface area available to participate in 

reactions and thus reduces the overall effectiveness of the catalyst. 

 

288 Beck, D.D., Sommers, J.W. (1995) Impact of sulfur on the performance of vehicle aged palladium 

monoliths. Applied Catalysis B: Environmental 6, 185-200. 

289 Maricq, M. M. Chace, R.E., Xu, N., Podsiadlik, D.H. (2002). The Effects of the Catalytic Converter and 

Fuel Sulfur Level on Motor Vehicle Particulate Matter Emissions: Gasoline Vehicles.” Environmental 

Science and Technology, 36, No. 2 pg. 276-282. 

290 The Effects of Ultra-Low Sulfur Gasoline on Emissions from Tier 2 Vehicles in the In-Use Fleet, EPA420-R-14-002.

291 See Preamble Section IV.A.6.c and Chapter 1 of the RIA (Section 1.2.3.2) for more details on this study 

and its results. 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 128 of 1039

 Operational conditions: It is not always possible to maintain fuel-rich 

operational conditions and exhaust catalyst temperatures that are high 

enough for sulfur removal because of cold weather, idle conditions and 

light-load operation.

 Increased emissions: In order to achieve greater emission reductions 

across a fuller range of in-use driving conditions, vehicle manufacturers’ 

use of commanded enrichment, which has been beneficial for sulfur 

removal, will be greatly reduced or eliminated under Tier 3. Additionally, 

the fuel-rich air-to-fuel ratios necessary for sulfur removal from active 

catalytic surfaces would result in increased PM, NMOG, CO and air toxic 

emissions, particularly at the high-temperature, high load conditions (e.g., 

US06 or comparable) necessary for sulfur removal. Previously used levels 

of commanded enrichment (e.g., under Tier 2) would interfere with the 

strategies necessary to comply with more stringent Tier 3 SFTP exhaust 

emissions standards. There are also additional provisions within the Tier 3 

standards that further restrict the use of US06 and off-cycle commanded 

enrichment in an effort to reduce high-load and off-cycle PM, NMOG, CO 

and air toxic emissions.292

 Expected changes to engine performance necessary to reduce fuel 

consumption and greenhouse gas emissions will improve the thermal 

efficiency of engines and may result in reduced exhaust temperatures.

b. Previous Studies of Gasoline Sulfur Impacts

This section summarizes studies to provide historical context regarding what is 

known about the direct impacts of gasoline sulfur on vehicle exhaust emissions. 

Reducing fuel sulfur levels has been the primary regulatory mechanism EPA has used to 

minimize sulfur contamination of exhaust catalysts and to ensure optimum emissions 

performance over the useful life of a vehicle. The impact of gasoline sulfur on exhaust 

catalyst systems has become even more important as vehicle emission standards have 

become more stringent. Studies have suggested a progressive increase in catalyst 

sensitivity to sulfur when standards increase in stringency and emissions levels decrease. 

Emission standards under the programs that preceded the Tier 2 program (Tier 0, Tier 1, 

and National LEV, or NLEV) were high enough that the impact of sulfur was considered 

of little importance. The Tier 2 program recognized the importance of sulfur and reduced 

the sulfur levels in the fuel from around 300 ppm to 30 ppm in conjunction with the new 

emission standards.293 At that time, very little work had been done to evaluate the effect 

 

292 See §86.1811-17 (LD) within the Tier 3 regulations. Tier 3 restrictions to commanded enrichment are 

also discussed in further detail within section IV.A.4.c of this preamble.

293 Tier 2 Regulatory Impact Analysis, EPA 420-R-99-023, December 22, 1999, last accessed on the 

Internet on 12/04/2013 at the following URL: http://epa.gov/tier2
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 129 of 1039

of further reductions in fuel sulfur, especially on in-use vehicles that may have some 

degree of catalyst deterioration due to real-world operation or on vehicles with extremely

low tailpipe emissions as described earlier.

In 2005, EPA and several automakers jointly conducted a research program, the 

Mobile Source Air Toxics (MSAT) Study that examined the effects of sulfur and other 

gasoline properties such as benzene and volatility on emissions from a fleet of nine Tier 2

compliant vehicles.294 The study found significant reductions in NOX, CO and total 

hydrocarbons (HC) when the vehicles were tested on low sulfur fuel, relative to 32 ppm 

fuel. In particular, the study found a 48 percent increase in NOX over the FTP when 

gasoline sulfur was increased from 6 ppm to 32 ppm. Given the preparatory procedures 

related to catalyst clean-out and loading used by these studies, these results may represent 

a “best case” scenario relative to what would be expected under more typical driving 

conditions. Nonetheless, these data suggested the effect of in-use sulfur loading was 

largely reversible for Tier 2 vehicles, and that there were likely to be significant emission 

reductions possible with further reductions in gasoline sulfur level. More recently, EPA 

completed a comprehensive study on the effects of gasoline sulfur on the exhaust 

emissions of Tier 2 vehicles at low to moderate mileage levels.295 Further details of this 

study are summarized in Section IV.A.6.c of this preamble. 

In the NPRM, we summarized the limited data available regarding the impact of 

gasoline sulfur on the near-zero exhaust emission vehicle technologies that will be 

necessary for Tier 3 compliance. Vehicles certified to California LEV II SULEV and 

PZEV standards and federal Tier 2 Bin 2 standards achieve levels of exhaust emissions 

control consistent with the levels of control that will be necessary for Tier 3 compliance. 

While these vehicles represent only a relatively small subset (e.g., typically small lightduty vehicles and light-duty trucks with limited GVWR or towing utility) of the broad 

range of vehicles that will need to comply with Tier 3 standards as part of a fleet-wide 

average, data on these vehicles provide an opportunity to study the impact of gasoline 

sulfur on near-zero exhaust emission technologies and is generally representative of 

technology that are expected to be used with mid-size and smaller light-duty vehicles for 

Tier 3 compliance. Vehicle testing by Toyota (Takei et al.) of LEV I, LEV II ULEV and 

prototype SULEV vehicles showed larger percentage increases in NOX and HC emissions 

for SULEV vehicles as gasoline sulfur increased from 8 ppm to 30 ppm, as compared to 

other LEV vehicles they tested.296 Ball et al. of Umicore Autocat USA, Inc. studied the 

 

294 Chapter 6 of the Regulatory Impact Analysis for the Control of Hazardous Air Pollutants from Mobile 

Sources Final Rule, EPA 420-R-07-002, February 2007, last accessed on the Internet on 12/04/2013 at the 

following URL: http://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=P1004LNN.PDF.

295 The Effects of Ultra-Low Sulfur Gasoline on Emissions from Tier 2 Vehicles in the In-Use Fleet, EPA420-R-14-002.

296 Takei, Y., Kungasa, Y., Okada, M., Tanaka, T. Fujimoto, Y. (2000). Fuel Property Requirement for 

Advanced Technology Engines. SAE Technical Paper 2000-01-2019. 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 130 of 1039

impact of gasoline fuel sulfur levels of 3 ppm and 33 ppm on the emissions of a 2009 

Chevrolet Malibu PZEV.297 Umicore’s testing of the Malibu PZEV vehicle showed a 

pronounced and progressive trend of increasing NOX emissions (referred to as “NOX

creep”) when switching from a 3 ppm sulfur gasoline to repeated, back-to-back FTP tests 

using 33 ppm sulfur gasoline. The PZEV Chevrolet Malibu, after being aged to an 

equivalent of 150,000 miles, demonstrated emissions at a level consistent with the Tier 3 

Bin 30 NMOG+NOX standards when operated on 3 ppm sulfur fuel and for at least one 

FTP test after switching to 33 ppm certification fuel. Following operation over 2 FTP 

cycles on 33 ppm sulfur fuel, NOX emissions alone were more than double the Tier 3 30 

mg/mi NMOG+NOX standard.271 This represents a 70% NOX increase between 3 ppm 

sulfur and 33 ppm sulfur gasolines, approximately 2-3 times of what has been previously 

reported for similar changes in fuel sulfur level for Tier 2 and older vehicles.298,299

Both the Umicore and Toyota studies suggest that the emissions from vehicles 

using near-zero exhaust emissions control technology similar to what is expected for 

compliance with the Tier 3 standards are more sensitive to changes in gasoline sulfur 

content at low (sub-30 ppm) sulfur concentrations than technology used to meet the 

higher Federal Tier 2 and California LEV II standards. The Umicore and Toyota studies 

clearly indicate that a progressive increase in catalyst sensitivity to sulfur continues as 

exhaust emissions decrease from levels required by federal Tier 2 and California LEV II 

emissions standards to the lower levels required by Tier 3 emissions standards. In 

addition, although vehicles with Tier 2 technology have somewhat less sulfur sensitivity

compared to future Tier 3 vehicles, there is still significant opportunity for further 

emissions reductions from the existing in-use fleet by reducing gasoline sulfur content 

from 30 ppm to 10 ppm. The results of recent testing demonstrating the potential for inuse emissions reductions from further gasoline sulfur control are summarized in Section 

IV.A.6.c. Recent data on the impact of gasoline sulfur on vehicles with exhaust emission 

control technologies that we expect to be used with Tier 3 vehicles is summarized in 

Sections IV.A.6.d and e.

c. EPA Testing of Gasoline Sulfur Effects on Tier 2 Vehicles and the In-Use 

Fleet

Both the MSAT300 and Umicore301 studies showed the emission reduction 

potential of lower sulfur fuel on Tier 2 and later technology vehicles over the FTP cycle. 

 

297 Ball, D., Clark, D., Moser, D. (2011). Effects of Fuel Sulfur on FTP NOX Emissions from a PZEV 4 

Cylinder Application. SAE Technical Paper 2011-01-0300. 

298 The Effects of Ultra-Low Sulfur Gasoline on Emissions from Tier 2 Vehicles in the In-Use Fleet, EPA420-R-14-002.

299 Shapiro, E. (2009). National Clean Gasoline – An Investigation of Costs and Benefits. Published by the 

Alliance of Automobile Manufacturers.

300 Chapter 6 of the Regulatory Impact Analysis for the Control of Hazardous Air Pollutants from Mobile 

Sources Final Rule, EPA 420-R-07-002, February 2007, last accessed on the Internet on 12/04/2013 at the 

following URL: http://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=P1004LNN.PDF
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 131 of 1039

However, assessing the potential for reduction on the in-use fleet requires understanding 

how sulfur exposure over time impacts emissions, and what the state of catalyst sulfur 

loading is for the typical vehicle in the field. In response to these data needs, EPA 

conducted a new study to assess the emission reductions expected from the in-use Tier 2 

fleet with a reduction in fuel sulfur level from current levels.302 It was designed to take 

into consideration what was known from prior studies on sulfur build-up in catalysts over 

time and the effect of periodic regeneration events that may result from higher speed and 

load operation over the course of day-to-day driving. 

The study sample described in this analysis consisted of 93 cars and light trucks 

recruited from owners in southeast Michigan, covering model years 2007-9 with 

approximately 20,000-40,000 odometer miles.303 The makes and models targeted for 

recruitment were chosen to be representative of high sales vehicles covering a range of 

types and sizes. Test fuels were two non-ethanol gasolines with properties typical of 

certification test fuel, one at a sulfur level of 5 ppm and the other at 28 ppm. All 

emissions data was collected using the FTP cycle at a nominal temperature of 75 °F.

Using the 28 ppm test fuel, emissions data were collected from vehicles in their 

as-received state as well as following a high-speed/load “clean-out” procedure consisting 

of two back-to-back US06 cycles intended to reduce sulfur loading in the catalyst. A 

statistical analysis of this data showed highly significant reductions in several pollutants 

including NOX and hydrocarbons, demonstrating that sulfur loadings have a large effect 

on exhaust catalyst performance, and that Tier 2 vehicles can achieve significant 

reductions based on removing, at least in part, the negative impact of the sulfur loading 

on catalyst efficiency (Table IV-6). For example, Bag 2 NOX emissions dropped 31 

percent between the pre- and post-cleanout tests on 28 ppm fuel. 

Table IV-6 Percent Reduction in In-Use Emissions After the Clean-out 

Using 28 ppm Test Fuela

NOX

(p-value)

THC

(p-value)

CO

(p-value)

NMHC

(p-value)

CH4

(p-value)

PM

(p-value)

Bag 1 – – 6.0% 

(0.0151)

– – 15.4%

(< 

 

301 Ball, D., Clark, D., Moser, D. (2011). Effects of Fuel Sulfur on FTP NOX Emissions from a PZEV 4 

Cylinder Application. SAE Technical Paper 2011-01-0300

302 The Effects of Ultra-Low Sulfur Gasoline on Emissions from Tier 2 Vehicles in the In-Use Fleet, EPA420-R-14-002.

303 The NPRM modeling was based on analysis of 81 passenger cars and trucks. Since the NPRM, twelve 

additional Tier 2 vehicles were tested and included in the statistical analysis described in the docketed final 

report, examining the effect of sulfur on emissions from Tier 2 vehicles. The analysis based on the 

complete set of 93 Tier 2 vehicles is reflected in the results presented in this section and the emissions 

modeling for FRM.
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 132 of 1039

0.0001)

Bag 2 31.4% 

(0.0003)

14.9% 

(0.0118)

– 18.7% 

(0.0131)

14.4% 

(0.0019)

–

Bag 3 35.4% 

(<0.0001)

20.4% 

(<0.0001)

21.5% 

(0.0001)

27.7% 

(<0.0001)

10.3% 

(<0.0001)

24.5% 

(<0.0001)

FTP 

Composite

11.4% 

(0.0002)

3.8% 

(0.0249)

6.8% 

(0.0107)

3.5% 

(0.0498)

6.0% 

(0.0011)

13.7% 

(<0.0001)

Bag 1 – Bag 3 – – 7.2%

(0.0656)

– – –

a The clean-out effect is not significant at α = 0.10 when no reduction estimate is provided.

To assess the impact of lower sulfur fuel on in-use emissions, further testing was 

conducted on a representative subset of vehicles on 28 ppm and 5 ppm fuel with 

accumulated mileage. A first step in this portion of the study was to assess the 

differences in the effectiveness of the clean-out procedure under different fuel sulfur 

levels. Table IV-7 presents a comparison of emissions immediately following (<50 

miles) the clean-out procedures at the low vs. high sulfur level. These results show 

significant emission reductions for the 5 ppm fuel relative to the 28 ppm fuel immediately

after this clean-out; for example, Bag 2 NOX emissions were 34 percent lower on the 5 

ppm fuel vs. the 28 ppm fuel. This indicates that the catalyst is not fully desulfurized, 

even after a clean out procedure, as long as there is sulfur in the fuel. This further 

indicates that current sulfur levels in gasoline continue to have a long-term, adverse effect 

on exhaust emissions control that is not fully removed by intermittent clean-out 

procedures that can occur in day-to-day operation of a vehicle and demonstrates that 

lowering sulfur levels to 10 ppm on average will significantly reduce the effects of sulfur 

impairment on emissions control technology. 

Table IV-7 Percent Reduction in Exhaust Emissions When Going from 28 ppm to 5 

ppm Sulfur Gasoline for the First Three Repeat FTP Tests Immediately Following 

Clean-out 

NOX

(p-value)

THC

(p-value)

CO

(p-value)

NMHC

(p-value)

CH4

(p-value)

PMa

Bag 1 5.3%

(0.0513)

6.8%

(0.0053)

6.2%

(0.0083)

5.7%

(0.0276)

14.0%

(<0.0001)

–

Bag 2 34.4%

(0.0036)

33.9%

(<0.0001)

–

a

26.4%

(0.0420)

49.4%

(<0.0001)

–

Bag 3 42.5%

(<0.0001)

36.9%

(<0.0001)

14.7%

(0.0041)

51.7%

(<0.0001)

28.5%

(<0.0001)

–

FTP Composite 15.0%

(0.0002)

13.3%

(<0.0001)

8.5%

(0.0050)

10.9%

(0.0012)

23.6%

(<0.0001)

–

Bag 1 – Bag 3 –

a

–

a

–

a

–

a

–

a

–

a The effectiveness of clean-out cycle is not significant at α = 0.10. 
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To assess the overall in-use reduction between high and low sulfur fuel, a mixed 

model analysis of all data as a function of fuel sulfur level and miles driven after cleanout 

was performed. This analysis found highly significant reductions for several pollutants, 

as shown in Table IV-8. Reductions for Bag 2 NOX were particularly high, estimated at 

52 percent between 28 ppm and 5 ppm overall. For all pollutants, the model fitting did 

not find a significant miles-by-sulfur interaction, suggesting the relative differences were 

not dependent on miles driven after clean-out. 

Table IV-8 Percent Reduction in Emissions from 28 ppm to 5 ppm Fuel Sulfur 

on In-Use Tier 2 Vehicles

NOX

(p-value)

THC

(p-value)

CO

(p-value)

NMHC

(p-value)

CH4

(p-value)

NOX+NMOG

(p-value) PMa

Bag 1 7.1%

(0.0216)

9.2%

(0.0002)

6.7%

(0.0131)

8.1%

(0.0017)

16.6%

(< 0.0001) N/A –

Bag 2 51.9%

(< 0.0001)

43.3%

(< 0.0001) –

a 42.7%

(0.0003)

51.8%

(< 0.0001) N/A –

Bag 3 47.8%

(< 0.0001)

40.2%

(< 0.0001)

15.9%

(0.0003)

54.7%

(< 0.0001)

29.2%

(< 0.0001) N/A –

FTP Composite 14.1%

(0.0008)

15.3%

(< 0.0001)

9.5%

(< 0.0001)

12.4%

(< 0.0001)

29.3%

(< 0.0001)

14.4%

(< 0.0001) –

Bag 1 – Bag 3 –

a 5.9%

(0.0074) –

a

–

b

–

b N/A –

a

Sulfur level not significant at α = 0.10. 

b Inconclusive because the mixed model did not converge. 

Major findings from this study include:

 Largely reversible sulfur loading is occurring in the in-use fleet of Tier 2 

vehicles and has a measureable effect on emissions of NOX, hydrocarbons, 

and other pollutants of interest.

 The effectiveness of high speed/load procedures in restoring catalyst 

efficiency is limited when operating on higher sulfur fuel.

 Reducing fuel sulfur levels from current levels to levels in the range of the 

Tier 3 gasoline sulfur standards is expected to achieve significant reductions 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

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in emissions of NOX, hydrocarbons, and other pollutants of interest in the 

current in-use fleet.

 Assuming that the emissions impacts vs. gasoline sulfur content are 

approximately linear, changing gasoline sulfur content from 30 ppm to 10 

ppm would result in NMOG+NOx emissions decreasing from 52 mg/mi to 45 

mg/mi, respectively (a 13% decrease), and NOx emissions decreasing from 19 

mg/mi to 16 mg/mi, respectively (a 16% decrease), for the vehicles in the 

study. 

To evaluate the robustness of the statistical analyses assessing the overall in-use 

emissions reduction between operation on high and low sulfur fuel (Table IV-8), a series 

of sensitivity analyses were performed to assess the impacts on study results of 

measurements from low-emitting vehicles and influential vehicles, as documented in 

detail in the report.304 The sensitivity analyses showed that the magnitude and the 

statistical significance of the results were not impacted and thus demonstrated that the 

results are statistically robust. We also subjected the design of the experiment and data 

analysis to a contractor-led independent peer-review process in accordance with EPA’s 

peer review guidance. The results of the peer review305,306 largely supported the study

design, statistical analyses, and the conclusions from the program and raised only minor 

concerns that have not changed the overall conclusions and have subsequently been 

addressed in the final version of the report.307 

Overall, the reductions found in this study are in agreement with other low sulfur 

studies conducted on Tier 2 vehicles, namely MSAT and Umicore studies mentioned 

above, in terms of the magnitude of NOX and HC reductions when switching from 28 

ppm to 5 ppm fuel.308 We have reviewed the results of the emission effects study

performed by SGS, which was included with API’s comments on the Tier 3 proposal, and 

have concluded that these results are also consistent with the findings of EPA’s Tier 2 inuse study, specifically that exhaust emissions performance is sensitive to fuel sulfur 

level.309 The SGS study also suggests that negative effects of exposure to a somewhat 

higher sulfur level (80 ppm in this case) are largely reversible for Tier 2 vehicles, 

meaning that reducing fuel sulfur levels nationwide will bring significant immediate 

 

304 The Effects of Ultra-Low Sulfur Gasoline on Emissions from Tier 2 Vehicles in the In-Use Fleet, EPA420-R-14-002.

305 Peer Review of the Effects of Fuel Sulfur Level on Emissions from the In-Use Tier 2 Vehicles, EPAHQ-OAR-2011-0135-1847. 

306 EPA In-Use Sulfur Report – Response to Peer-Review Comments, EPA-HQ-OAR-2011-0135-1848.

307 The Effects of Ultra-Low Sulfur Gasoline on Emissions from Tier 2 Vehicles in the In-Use Fleet, EPA420-R-14-002.

308 Ball, D., Clark, D., Moser, D. (2011). Effects of Fuel Sulfur on FTP NOX Emissions from a PZEV 4 

Cylinder Application. SAE Technical Paper 2011-01-0300.

309 American Petroleum Institute. 2013. Supplemental Comments of the American Petroleum Institute. 

Available in the docket for this final rule, docket no. EPA-HQ-OAR-2011-0135
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benefits by reducing emissions of the existing fleet. For further details regarding the Tier 

2 In-Use Gasoline Sulfur Effects Study, see the final report.310

As a follow-on phase to the Tier 2 in-use study, EPA analyzed five vehicles311

certified to Tier 2 Bin 4, LEV II ULEV and LEV II SULEV exhaust emissions standards 

to assess the gasoline sulfur sensitivity of Tier 2 and California LEV II vehicles with 

emission levels approaching or comparable to the Tier 3 standards. The analysis found 

that these low-emitting Tier 2 vehicles showed similar or greater sensitivity to fuel sulfur 

levels compared to the original Tier 2 test fleet – for example, a 24 percent reduction in 

FTP composite NOx emissions when sulfur is reduced from 28 ppm to 5 ppm.312 Test 

results discussed below in section IV.A.6.d also confirm that there is significantly

increased sensitivity of exhaust emissions to gasoline sulfur as vehicle technologies 

advance towards exhaust emissions approaching near-zero emissions (e.g., Tier 3 Bin 50 

and lower). The impact of fuel sulfur on vehicles with exhaust emission control 

technologies that we expect to be used with Tier 3 vehicles is summarized in the next two 

sections (Preamble IV.A.6.d and e). 

EPA believes that the studies by EPA and others described in this section strongly 

support our conclusion that reducing gasoline sulfur content to a 10 ppm average will 

result in significant exhaust emissions reductions from the current in-use fleet. However, 

some commenters have expressed concerns about the relevance and appropriateness of 

the data, as well as the conclusions drawn from them. The Summary and Analysis of 

Comments document, available in the docket for this rulemaking, provides our responses 

to those comments.

d. Testing of Gasoline Sulfur Effects on Vehicles with Tier 3/LEV III 

Technology

The Tier 3 fleet average exhaust emissions standards of 30 mg/mi NMOG+NOx 

will require large reductions of emissions across a broad range of light-duty vehicles and 

trucks with differing degrees of utility. Previous studies of sulfur impacts on extremely

low exhaust emission vehicles (e.g., Toyota, Umicore) were limited to mid-size or 

smaller light-duty vehicles. There are currently no LDT3 or any LDT4 vehicles certified 

at or below Federal Tier 2 Bin 3 or to the California LEV II SULEV exhaust emission 

standards with the exception of a single hybrid electric SUV. At the time of the Tier 3 

NPRM, EPA was not aware of any existing data demonstrating the impact of changes in 

gasoline sulfur content on larger vehicles with technology comparable to what would be 

 

310 The Effects of Ultra-Low Sulfur Gasoline on Emissions from Tier 2 Vehicles in the In-Use Fleet, EPA420-R-14-002. 

311 The make and model of the tested vehicles are Honda Crosstour, Chevrolet Malibu, Chevrolet Silverado, 

Ford Focus and Subaru Outback.

312 The Effects of Ultra-Low Sulfur Gasoline on Emissions from Tier 2 Vehicles in the In-Use Fleet, EPA420-R-14-002.
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expected for compliance with Tier 3 exhaust emission standards. In their supplemental 

comments to the Tier 3 proposal, API criticized EPA’s reliance on emissions data from 

older vehicles that were not considered to be examples of future Tier-3-like vehicles. In 

order to further evaluate this issue, the Agency initiated a test program at EPA’s National 

Vehicle and Fuel Emissions Laboratory (NVFEL) in Ann Arbor, Michigan. The Agency

obtained a heavy-light-duty truck and applied changes to the design and layout of the 

exhaust catalyst system and to the calibration of the engine management system 

consistent with our engineering analyses of technology necessary to meet Tier 3 Bin 30 

emissions with a 20 to 40% compliance margin at 150,000 miles. EPA also requested 

that Umicore loan the Agency the vehicle tested in their study to undergo further 

evaluation of gasoline sulfur impacts on exhaust emissions. In addition, Ford Motor 

Company completed testing of fuel sulfur effects on a Tier 3/LEV III developmental 

heavy-light-duty truck and submitted a summary report of their findings as part of their 

supplemental comments to the Tier 3 NPRM. The results of these three test programs are 

summarized below. 

i. Ford Motor Company Tier 3 Sulfur Test Program

Ford Motor Company recently completed testing of a heavy-light-duty truck (i.e., 

between 6000 and 8500 pounds GVWR) under development to meet the Tier 3 Bin 50 

standards on two different fuel sulfur levels and submitted the resulting data to EPA as 

part of its supplemental comments. 313,314 The test results from this vehicle are 

particularly important when considering the following factors:

 These are the first detailed emissions data submitted by a vehicle 

manufacturer to the Agency demonstrating emissions of a heavy-lightduty-truck consistent with Tier 3 Bin 50 or lower emissions levels.

 The truck tested uses a version of Ford’s 2.0 L GTDI engine, an engine 

with high BMEP (approximately 23-bar) that can allow significant engine 

displacement downsizing while maintaining the truck’s utility. This is a 

key enabling GHG reduction strategy analyzed by EPA in the 2017-2025 

GHG Final Rule.315 

 

313 Ford Motor Company. 2013. “Quality Changes Needed to Meet Tier 3 Emission Standards and Future 

Greenhouse Gas Requirements.” Attachment 2: “Tier 3 Sulfur Test Program – Ford Motor Company 

Summary Report.” Available within EPA Docket for this final rule, EPA-HQ-2011-0135.

314 Dominic DiCicco, Ford Motor Company. 2013. “Additional data as requested. RE: Ford Supplemental 

Comments on Tier 3.” Available within EPA Docket for this final rule, EPA-HQ-2011-0135.

315 See 77 FR 62840-62862, October 15, 2012; and Joint Technical Support Document: Final Rulemaking 

for 2017-2025 Light-Duty Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel 

Economy Standards (EPA-420-R-12-901), August 2012, Chapter 3.4.1.7 - 3.4.1.8 (pages 3-88 – 3-95).
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 The vehicle was specifically under development by a vehicle manufacturer 

with an engineering target of meeting Tier 3 Bin 50 and LEV III ULEV50 

exhaust emissions standards.

Turbocharged, downsized engines are key technologies within Ford’s strategy to reduce 

GHG emissions.316 EPA expects that trucks with configurations similar to this 

developmental Ford Explorer (downsized engines with reduced GHG emissions and very

low emissions of NMOG+NOx) will become increasingly prevalent within the timeframe 

of the implementation of the Tier 3 regulations. 

The developmental truck used close-coupling of both catalyst substrates and 

relatively high PGM loading (150 g/ft3). Ford used accelerated aging of the catalysts and 

O2 sensors to an equivalent of 150,000 miles (the Tier 3 full useful life). The 

developmental hardware and engine management calibration configuration of this truck 

was designed to meet federal Tier 3 Bin 50 and California LEV III ULEV50 standards of 

50 mg/mi NMOG+NOx at 150,000 miles. The emissions data submitted by Ford 

included NOx and NMHC emissions during operation on E10 California LEV III 

certification fuel at two different sulfur levels, 10 ppm and 26.5 ppm. Ford did not 

provide NMOG emissions data but there was sufficient information for EPA to calculate 

NMOG emissions from the provided NMHC data using calculations from Title 40 CFR 

1066.665. 

The truck demonstrated average FTP NMOG+NOx emissions of 37 mg/mi on the 

10 ppm E10 California LEV III fuel, emissions that are consistent with compliance with 

Bin 50 and ULEV50 standards with a reasonable margin of compliance (emissions at 

approximately 70% of the standard). Retesting of the same vehicle on LEV3 E10 

blended317 to 26.5 ppm S resulted in average NMOG+NOx emissions of 53 mg/mi, 6% 

above the Tier 3 Bin 50 standard. Ford found a high level of statistical significance with 

respect to the increase of emissions with increasing fuel sulfur. Assuming a linear effect 

of sulfur on emissions performance, NMOG+NOx emissions would be approximately 56 

mg/mi at 30 ppm sulfur, which is approximately 12% above the Bin 50 exhaust emissions 

standard. This also represents an increase in NMOG+NOx emissions of 53% with an 

approximate doubling of NOx emissions and a 13 % increase in NMOG for 30 ppm 

sulfur gasoline vs. 10 ppm sulfur gasoline.

The advanced technology Ford truck, which was shown to be capable of 

complying with the Tier 3 Bin 50 standard with a reasonable margin of compliance on 10 

ppm sulfur gasoline, in effect reverted to approximately LEV II ULEV exhaust emissions 

levels when tested on higher sulfur gasoline, equivalent to the previous level of emissions 

 

316 Ford Motor Company, 2012. “Sustainability 2011/2012 – Improving Fuel Economy.” Accessed on the 

Internet on 11/21/2013 at: http://corporate.ford.com/microsites/sustainability-report-2011-12/environmentproducts-plan-economy. Available within EPA Docket for this final rule, EPA-HQ-2011-0135.

317 Ford used the same tert-butyl sulfide fuel sulfur additives used within the EPA testing in IV.A.6.c and d.
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control to which earlier models of this vehicle were certified for MY 2013. The effect of 

increasing gasoline sulfur levels from 10 ppm to 30 ppm318 on this vehicle essentially

negated the entire benefit of the advances in emissions control technology that were 

applied by the vehicle manufacturer to meet developmental goals for compliance with 

Tier 3 standards. This clearly indicates, for this vehicle model using technology 

representative of what would be expected for compliance with Tier 3 Bin 50 and post 

2017 GHG standards, reducing gasoline sulfur to 10 ppm is needed for the advances in 

technology to achieve their intended effectiveness in reducing NMOG+NOx emissions. 

The advances in vehicle technology and the reduction in gasoline sulfur clearly are both 

needed to achieve the emissions reductions called for by Tier 3. 

ii. EPA Re-test of Umicore 2009 Chevrolet Malibu PZEV

Ball et al. of Umicore Autocat USA, Inc. previously studied the impact of 

gasoline fuel sulfur levels of 3 ppm and 33 ppm on the emissions of a 2009 Chevrolet 

Malibu PZEV.319 In their supplemental comments, API commented that the composition 

of the two test fuels outside of sulfur content was not held constant and thus the exhaust 

emissions differences attributed to the difference in gasoline sulfur levels may have been 

due to other fuel property differences. For example, the 3 ppm fuel used by Ball et al. was 

nonoxygenated EEE Clear test fuel (essentially, Tier 2 Federal certification gasoline 

except with near-zero sulfur) while the 33 ppm fuel was an oxygenated California Phase 

2 LEV II certification fuel. Thus it was not entirely clear if the changes in NOx emissions 

observed between tests with the two fuels were significantly impacted by fuel 

composition variables other than gasoline sulfur content. EPA obtained the same test 

vehicle from Umicore for retesting at the EPA NVFEL facility using the 5 ppm and 28 

ppm sulfur E0 test fuels and vehicle test procedures used in EPA gasoline sulfur effects 

testing on Tier 2 vehicles (see Section IV.6.b). 

In EPA’s retest of the 2009 Chevrolet Malibu PZEV, when sulfur was the only

difference between the test fuels, the gasoline with higher sulfur resulted in significantly 

higher increases in NOx emissions with increasing fuel sulfur content than was observed 

in the previous testing by Ball et al. at Umicore. Assuming emissions impacts vs. 

gasoline sulfur content are approximately linear, the original data from Ball et al. would 

have resulted in a predicted increase in NOx emissions of approximately 40% when 

increasing gasoline sulfur from 10 ppm to 30 ppm. The EPA re-testing of the same 

vehicle that controlled for other fuel composition differences resulted in a predicted 

increase in NOx emissions of 93% when increasing gasoline sulfur from 10 ppm to 30 

ppm, with NOx emissions approximately doubling from 22 g/mi to 43 g/mi, with no 

statistically significant difference in NMOG emissions and with an increase in 

 

318Emissions at 30 ppm sulfur estimated assuming approximately linear emissions effects between 10, 26.5 

and 30 ppm gasoline sulfur levels.

319 Ball, D., Clark, D., Moser, D. (2011). Effects of Fuel Sulfur on FTP NOX Emissions from a PZEV 4 

Cylinder Application. SAE Technical Paper 2011-01-0300. Available in the docket for this final rule.
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NMOG+NOx emissions of 56%. The approximate doubling in NOx emissions with the 

Malibu PZEV between 10 ppm and 30 ppm sulfur was nearly identical to the results 

found during testing of the Tier 3 Bin 50 developmental Ford Explorer discussed above. 

The results confirm that fuel compositional differences other than sulfur may have 

impacted exhaust emissions results in the Ball et al. study by underreporting a substantial 

portion of the effect of increased sulfur on NOx emissions. When controlling for other 

fuel composition differences, the resultant increase in NOx exhaust emissions due to 

increasing gasoline sulfur was more than double that observed in the original Ball et al. 

study. The observed increase in NMOG+NOx emissions during EPA testing of the 

Malibu PZEV was also comparable to results found with the developmental Tier 3 Bin 50 

Ford Explorer. There was also a much higher increase in NOx and NMOG+NOx 

emissions for both the Malibu PZEV and the Tier 3 Bin 50 Explorer with increased 

gasoline sulfur than was observed with Tier 2 vehicles in the EPA Tier 2 in-use study. 

(See also Chapter 1.2.4 of the RIA) 

iii.EPA Prototype Tier 3 Heavy-light-duty Truck Test Program

EPA purchased a 2011 Chevrolet Silverado heavy-light-duty (LDT4) pickup truck 

with a developmental goal of modifying the truck to achieve exhaust emissions consistent 

with compliance with the Tier 3 Bin 30 emissions standards. The truck was equipped 

with a 5.3L V8 with General Motors’ “Active Fuel Management” cylinder deactivation 

system. This particular truck was chosen in part because cylinder deactivation is a key

technology for light-truck compliance with future GHG standards and in part because it 

achieved very low emissions in its OEM, Tier 2-compliant configuration (certified to Tier 

2 Bin 4). A prototype exhaust system was obtained from MECA consisting of high-celldensity (900 cpsi) thin-wall (2.5 mil), high-PGM, close-coupled Pd-Rh catalysts with an 

additional under-body Pd-Rh catalyst. The total catalyst volume was approximately 116 

in3 with a specific PGM loading of 125 g/ft3and approximate loading ratio of 0:80:5 

(Pt:Pd:Rh). Third-party (non-OEM) EMS calibration tools were used to modify the 

powertrain calibration in an effort to improve catalyst light-off performance. The final 

test configuration used approximately 4 degrees of timing retard and approximately 200 

rpm higher idle speed relative to the OEM configuration during and immediately

following cold-start. The exhaust catalyst system and HEGO sensors were bench aged to 

an equivalent 150,000 miles using standard EPA accelerated catalyst bench-aging 

procedures.320 The truck was tested on California LEV III E10 certification fuel at 9 and 

29 ppm gasoline sulfur levels.

The EPA Tier 3 prototype Silverado achieved NMOG+NOx emissions of 18 

mg/mi on the 9 ppm S fuel. The NMOG+NOx emissions were approximately 60% of the 

Bin 30 standard and thus are consistent with meeting the Tier 3 Bin 30 exhaust emissions 

 

320 U.S. Code of Federal Regulations, Title 40, §86.1823–08 “Durability demonstration procedures for 

exhaust emissions.”
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standard with a moderate compliance margin. NMOG+NOx emissions increased to 29 

mg/mi on the 29 ppm S fuel and one out of four tests exceeded the Bin 30 exhaust 

emissions standards. NMOG+NOx emissions would be at 19 mg/mi and 30 mg/mi with 

10 ppm and 30 ppm gasoline sulfur, respectively, assuming a linear effect of sulfur on 

emissions performance. This represents an increase in NMOG+NOx emissions of 

approximately 55%, comparable to increases observed with both the EPA-tested 

Chevrolet Malibu PZEV and the developmental Tier 3 Bin 50 Ford Explorer. The impact 

of increased gasoline sulfur on NMOG+NOx emissions was due to comparable increases 

(on a percentage basis) in both NMOG and NOx emissions. This effect of gasoline sulfur 

on the Prototype Silverado truck’s emissions differed from the sulfur impacts observed 

on the developmental Ford Explorer, which primarily affected NOx emissions, and the 

Malibu PZEV, where the impact was entirely on NOx emissions. 

e. Gasoline Sulfur Level Necessary for New Light-duty Vehicles to Achieve Tier 

3 Exhaust Emissions Standards

Meeting Tier 3 NMOG+NOx standards will require major reductions in exhaust 

emissions across the entire fleet of new light-duty vehicles. As discussed in previous 

sections, the Tier 3 program will require reductions in fleet average NMOG+NOx

emissions of over 80 percent for the entire fleet of light-duty vehicles and light-duty 

trucks. This significant level of fleet average emission reduction will require reductions 

from all parts of the fleet, including vehicles models with exhaust emissions currently at 

or near the level of the fully phased-in Tier 3 FTP NMOG+NOx fleet average standard of 

30 mg/mi.

Compliance with the more stringent Tier 3 fleet average standards will require 

vehicle manufacturers to certify a significant amount of vehicles to bin standards that are 

below the Bin 30 fleet average standard to offset other vehicles that are certified to bin 

standards that remain somewhat above the Bin 30 fleet average even after significantly 

reducing their emissions. At the same time, the stringency of the Tier 3 standards will 

push almost all vehicle models to be close to or below the Bin 30 fleet average standard. 

There are only 2 compliance bins below Bin 30, i.e., Bin 20 and Bin 0, available to offset 

emissions of vehicles certifying above Bin 30. There is also very limited ability for 

vehicle manufacturers to certify vehicles below the stringent Tier 3 fleet average exhaust 

emissions standard since Bin 20 and Bin 30 standards for individual vehicle certification 

test groups are approaching the engineering limits of what can be achieved for vehicles 

using an internal combustion engine and Bin 0 can only be achieved by electric-only 

vehicle operation. The result is that there is a very limited ability to offset sales of 

vehicles certified above the 30 mg/mi fleet average emission standard. This means in 

general that vehicle models currently with higher emissions will have to achieve 

significant emissions reductions to minimize the gap, if any, between their certified bin 

levels under Tier 3 and the Tier 3 Bin 30 fleet average standard, and vehicle models 

currently at or below Bin 30 will also have to achieve further emissions reductions under 

Tier 3 to offset the vehicles that remain certified to bin standards somewhat above Bin 

30l. The end result is a need for major reductions from all types of vehicles in the light-
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duty fleet, including those above as well as most vehicles that are already near, at, or 

below the Tier 3 Bin 30 fleet average standard.

Achieving exhaust emissions reductions of over 80% for the fleet, with major 

reductions across all types of light-duty vehicles and light-duty trucks, will be a major 

technological challenge. Vehicles already have made significant advances in controlling 

cold start emissions and maximizing exhaust catalyst efficiency (e.g., improving warmup and catalyst light-off after cold starts and maintaining very high catalyst efficiency

once warmed up) in order to meet Tier 2 and LEV II emissions standards. There are no 

“low-hanging fruit” remaining for additional NMOG+NOx reductions from light-duty

vehicles from a technology perspective, meaning that vehicle manufacturers cannot 

merely change one aspect of emissions control and thereby achieve all of the required 

reductions. Instead, compliance with light-duty Tier 3 exhaust emissions standards will 

require significant improvements in all areas of emissions control – with further 

improvements in fuel-system management and mixture preparation during cold start, 

improvements in achieving catalyst light-off immediately after cold start, and improved 

catalyst efficiency during stabilized, fully-warmed-up conditions. Manufacturers will 

need further improvements in each of these areas with nearly every vehicle in order to 

comply with the fleet-average Tier 3 standards. 

From a technology perspective, the most likely control strategies will involve 

using exhaust catalyst technologies and powertrain calibration primarily focused on 

reducing cold-start emissions of NMOG, and on reducing both cold-start and warmed-up 

(running) emissions of NOX. An important part of this strategy, particularly for larger 

vehicles having greater difficulty achieving cold-start NMOG emissions control, will be 

to reduce NOX emissions to near-zero levels. This will involve controlling engine-out 

NOx emissions during cold start, shortening the cold start period prior to catalyst light-off 

of NOx reduction reactions, and better controlling NOx emissions once the catalyst is 

fully warmed up. This is needed to allow a sufficient NMOG compliance margin so that 

vehicles can meet the combined NMOG+NOX emissions standards for their full useful 

life.

While significant NMOG+NOx emissions reductions can be achieved from better 

control of cold start NMOG emissions, there are practical engineering limits to NMOG 

control for larger displacement vehicles (e.g., large light-duty trucks with significant 

payload and trailer towing capabilities). This is based in part on the impact on NMOG 

emissions of the larger engine surface-to-volume ratio and resultant heat conduction from 

the combustion chamber during warm-up. There are also tradeoffs between some coldstart NMOG controls and cold-start NOx control. For example, secondary air injection 

and/or leaner fueling strategies improve catalyst light-off for NMOG after a cold-start but 

also place OSC components in an oxidation state that limits potential for NOx reduction 

and thus often result in higher cold-start NOx emissions. Some applications achieve 

lower NMOG+NOx emissions without the use of secondary air injection by careful 

calibration, changes to the catalyst formulation and balancing of catalyst HC and NOx 
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activity. The EPA Prototype Silverado and the developmental Ford Explorer are specific 

examples of this approach. 

Because of engineering limitations with large vehicles, heavy-light-trucks and 

other vehicles with significant utility, we expect many applications will need close to 

100% efficiency in NOx control under fully warmed-up conditions and very fast light-off 

of NOx reduction reactions over the exhaust catalyst almost immediately after cold-start 

for those applications. This will require significant improvements in catalytic and 

engine-out NOx reduction compared with Tier 2 vehicles and will be especially important 

for heavier vehicles due to the challenges of achieving low NMOG. 

These technology improvements - improving warm-up and catalyst light-off after 

cold starts and maintaining very high catalyst efficiency - - once warmed up – all rely on 

10 ppm average sulfur fuel to achieve the very significant emissions reductions required 

for the fleet to achieve the Tier 3 Bin 30 fleet average emissions standard. The evidence 

from the test results and specific vehicle examples discussed above clearly indicate that 

leaving the gasoline sulfur level at 30 ppm would largely negate the benefits of key 

technology improvements expected to be used for compliance with Tier 3 exhaust 

emissions standards. Without the lower 10 ppm gasoline sulfur content, the Tier 3 

exhaust fleet average emissions standards would not be achievable across the broad range 

of vehicles that must achieve significant exhaust emissions reductions. 

One aspect of the need for sulfur levels of 10 ppm average stems from the fact 

that achieving the Tier 3 emission standards will require very careful control of the 

exhaust chemistry and exhaust temperatures to ensure high catalyst efficiency. The 

impact of sulfur on OSC components in the catalyst makes this a challenge even at 

relatively low (10 ppm) gasoline sulfur levels. NOX conversion by exhaust catalysts is 

strongly influenced by the OSC components like ceria. Ceria sulfation may play an 

important role in the large degradation of NOX emission control with increased fuel sulfur 

levels observed in the MSAT, Umicore and EPA Tier 2 In-Use Gasoline Sulfur Effects 

studies and the much more severe NOx emissions degradation observed in recent test 

data from PZEV and prototype/developmental Tier 3/LEV III vehicles. 321

The importance of lower sulfur gasoline is also demonstrated by the fact that 

vehicles certified to California SULEV are typically certified to higher bins for the 

federal Tier 2 program. Light-duty vehicles certified to CARB SULEV and federal Tier 2 

Bin 2 exhaust emission standards accounted for approximately 3.1 percent and 0.4 

percent, respectively, of vehicle sales for MY2009. Light-duty vehicles certified to 

SULEV under LEV II are more typically certified federally to Tier 2 Bin 3, Bin 4 or Bin 

5, and vehicles certified to SULEV and Tier 2 Bins 3-5 comprised approximately 2.5 

percent of sales for MY2009. In particular, nonhybrid vehicles certified in California as 

 

321 Heck, R.M., Farrauto, R.J. (2002). Chapter 6: Automotive Catalyst in Catalytic Air Pollution Control, 

2

nd Edition. John Wiley and Sons, Inc.
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SULEV are not certified to federal Tier 2 Bin 2 emissions standards even though the 

numeric limits for NOX and NMOG are shared between the California LEV II and federal 

Tier 2 programs for SULEV and Bin 2. Confidential business information shared by the 

auto companies indicate that the primary reason is an inability to demonstrate compliance 

with SULEV/Bin 2 emission standards after vehicles have operated in-use on gasoline 

with greater than 10 ppm sulfur and with exposure to the higher sulfur gasoline sold 

nationwide. While vehicles certified to the LEV II SULEV and Tier 2 Bin 2 standards 

both demonstrate compliance using certification gasoline with 15-40 ppm sulfur content, 

in-use compliance of SULEV vehicles in California occurs after significant, sustained 

operation on gasoline with an average of 10 ppm sulfur and a maximum cap of 30 ppm 

sulfur while federally certified vehicles under the Tier 2 program operate on gasoline 

with an average of 30 ppm sulfur and a maximum cap of 80 ppm sulfur. Although the 

SULEV and Tier 2 Bin 2 standards are numerically equivalent, the increased sulfur 

exposure of in-use vehicles certified under the federal Tier 2 program results in a need for 

a higher emissions compliance margin to take into account the impact of in-use gasoline 

sulfur on full useful life vehicle emissions. As a result, vehicles certified to California 

SULEV typically certify to emissions standards under the federal Tier 2 program that are 

1-2 certification bins higher (e.g., SULEV certified federally as Tier 2 Bin 3 or Bin 4) in 

order to ensure in-use compliance with emissions standards out to the full useful life of 

the vehicle when operating on higher-sulfur gasoline.

There are currently no LDTs larger than LDT2 with the exception of a single 

hybrid electric SUV certified to Tier 2 Bin 2 or SULEV emissions standards. We expect 

that additional catalyst technologies, for example increasing catalyst surface area (volume 

or substrate cell density) and/or increased PGM loading, will need to be applied to larger 

vehicles in order to achieve the catalyst efficiencies necessary to comply with the Tier 3 

standards, and any sulfur impact on catalyst efficiency will have a larger impact on 

vehicles and trucks that rely more on very high catalyst efficiencies in order to achieve 

very low emissions. The vehicle emissions data referenced in Section IV.A.6.d represents 

the only known data on non-hybrid vehicles spanning a range from mid-size LDVs to 

heavy-light-trucks at the very low criteria pollutant emissions levels that will be needed 

to comply with the Tier 3 exhaust emissions standards. The developmental Ford 

Explorer, Chevrolet Malibu PZEV and EPA prototype Chevrolet Silverado vehicles 

described in section IV.A.6.c also represent a range of different technology approaches to 

both criteria pollution control and GHG reduction (e.g., use of secondary air vs. 

emphasizing cold-start NOx control, use of engine downsizing via turbocharging vs. 

cylinder deactivation for GHG control, etc.) and represent a broad range of vehicle 

applications and utility (mid-size LDV, LDT3, LDT4). All of the vehicles with Tier 

3/LEV III technology demonstrated greater than 50% increases in NMOG+NOx 

emissions when increasing gasoline sulfur from 10 ppm to 30 ppm. Two of the vehicles 

showed a doubling of NOx emissions when increasing gasoline sulfur from 10 ppm to 30 

ppm. Both of the heavy-light-duty trucks with specific engineering targets of meeting 

Tier 3 emissions were capable of meeting their targeted emission standards with a 

sufficient compliance margin on 10 ppm sulfur gasoline and could not meet their targeted 
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emissions standards or could not achieve a reasonable compliance margin when tested 

with 30 ppm sulfur gasoline. 

The negative impact of gasoline sulfur on catalytic activity and the resultant loss 

of exhaust catalyst effectiveness to chemically reduce NOX and oxidize NMOG occur 

across all vehicle categories. However, the impact of gasoline sulfur on the effectiveness 

of exhaust catalysts to control NOX emissions in the fully-warmed-up condition is 

particularly of concern for larger vehicles (the largest LDVs and LDT3s, LDT4s, and 

MDPVs). Manufacturers face the most significant challenges in reducing cold-start 

NMOG emissions for these vehicles. Because of the need to reach near-zero NOX

emissions levels in order to offset engineering limitations on further NMOG exhaust 

emissions control with these vehicles, any significant degradation in NOX emissions 

control over the useful life of the vehicle would likely prevent some if not most larger 

vehicles from reaching a combined NMOG+NOX level low enough to comply with the 

30 mg/mi fleet-average standard. Any degradation in catalyst performance due to 

gasoline sulfur would reduce or eliminate the margin necessary to ensure in-use 

compliance with the Tier 3 emissions standards. Certifying to a useful life of 150,000 

miles versus the current 120,000 miles will further add to manufacturers’ compliance 

challenge for Tier 3 large light trucks (See Section IV.A.7.c below for more on the useful 

life requirements.) These vehicles represent a sufficiently large segment of light-duty 

vehicle sales now and for the foreseeable future such that their emissions could not be 

sufficiently offset (and thus the fleet-average standard could not be achieved) by

certifying other vehicles to bins below the fleet average standard. 

As discussed above, achieving Tier 3 levels as an average across the light-duty

fleet will require fleet wide reductions of approximately 80%. This will require 

significant reductions from all light duty vehicles, with the result that some models and 

types of vehicles will be at most somewhat above the Tier 3 level, and all other models 

will be at or somewhat below Tier 3 levels. Achieving these reductions presents a major 

technology challenge. The required reductions are of a magnitude that EPA expects 

manufacturers to employ advances in technology in all of the relevant areas of emissions 

control – reducing engine-out emissions, reducing the time to catalyst lightoff, improving 

exhaust catalyst durability at 120,000 or 150,000 miles and improving efficiency of fully

warmed up exhaust catalysts. All of these areas of emissions control need to be 

improved, and gasoline sulfur reduction to a 10 ppm average is a critical part of achieving 

Tier 3 levels through these emissions control technology improvements. 

The use of 10 ppm average sulfur fuel is an essential part of achieving Tier 3 

levels while applying an array of advancements in emissions control technology to the 

light-duty fleet. The testing of Tier 2 and Tier 3 type technology vehicles, as well as 

other information, shows that sulfur has a very large impact on the effectiveness of the 

control technologies expected to be used in Tier 3 vehicles. Without the reduction in 

sulfur to a 10 ppm average, the major technology improvements projected under Tier 3 

would only result in a limited portion of the emissions reductions needed to achieve Tier 

3 levels. For example, without the reduction in sulfur from a 30 ppm to 10 ppm average, 
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the technology improvements would not come close to achieving Tier 3 levels. In some 

cases this may result in the same effectiveness as the current Tier 2 technology and 

achieve only approximately Tier 2 levels of exhaust emissions control. 

Achieving Tier 3 levels without a reduction in sulfur to 10 ppm levels would only

be possible if there were technology improvements significantly above and beyond those 

discussed above. Theoretically, without reducing sulfur levels to 10 ppm average, 

emissions control technology improvements would need to provide upwards of twice as

much, and in some cases significantly more than twice as much, emissions control 

effectiveness as the Tier 3 technology improvements discussed above in Section 

IV.A.6.d. EPA has not identified technology improvements that could provide such a 

large additional increase in emissions control effectiveness, across the light-duty fleet, 

above and beyond that provided by the major improvements in technology discussed 

above, without any additional gasoline reductions in gasoline sulfur content. The impact 

of sulfur reduction on the effectiveness of the available technology improvements plays 

such a large role in achieving the Tier 3 levels that there would be no reasonable basis to 

expect that technology would be available, at the 30 ppm sulfur level, to fill the emission 

control gap left from no sulfur reduction, and achieve the very significant fleetwide 

reductions needed to meet the Tier 3 fleet average standards. In effect reducing sulfur 

from 30 ppm to 10 ppm has such a large impact on the ability of the technology

improvements to achieve Tier 3 emissions levels that absent these sulfur reductions there 

is not a suite of technology advancements available to fill the resulting gap in emissions 

reductions. We cannot identify a technology path for vehicles that would achieve the 

Tier 3 Bin 30 average standard, across the fleet, with sulfur at 30 ppm levels, and as a 

result Tier 3 levels would not be technically feasible and achievable. 

This analysis also applies to gasoline sulfur levels between 10 and 30 ppm, e.g., 

20 ppm. The Tier 3 required emissions reductions are so large and widespread across the 

fleet, and the technology challenges are sufficiently high, especially for heavier vehicles, 

that the large increase in emissions that would occur from a higher average sulfur level 

compared to a 10 ppm average would lead to an inability for vehicle technologies to 

widely achieve Tier 3 levels as a fleet wide average in order to meet the Bin 30 fleet 

average standard.

EPA acknowledges that some models in the light-duty fleet, when viewed in 

isolation, may be able to achieve Tier 3 levels at current sulfur levels of 30 ppm average. 

Under the Tier 3 fleet average standards, it is not sufficient for one or a few of a 

manufacturer’s vehicle models to meet Tier 3 levels because the manufacturer’s lightduty vehicle fleet as a whole must achieve the Tier 3 30 mg/mi exhaust emissions 

standard as a fleet-wide average. As discussed above, all vehicle models will need to 

achieve further reductions and be either below or no more than somewhat above Tier 3 

levels to achieve the Tier 3 standard as a fleet wide average. Absent the reductions in 

sulfur levels to 10 ppm average, this is not achievable from a technology perspective.
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 As discussed in Section V.B, the average 10 ppm gasoline sulfur standard is 

feasible and is the level that appropriately balances costs with the emission reductions 

that it provides and enables. Not only will a 10 ppm sulfur standard enable vehicle 

manufacturers to certify their entire product line of vehicles to the Tier 3 fleet average 

standards, but reducing gasoline sulfur to 10 ppm will better enable these vehicles to 

maintain their emission performance in-use over their full useful life. Higher sulfur 

levels would make it impossible for vehicle manufacturers to meet the Tier 3 standards, 

and would forego the very large immediate reductions from the existing fleet. Reducing 

the sulfur level below 10 ppm would further reduce vehicle emissions and allow the Tier 

3 vehicle standards to be achieved more easily. However, we believe that a 10 ppm 

average standard is sufficient to allow vehicles to meet the Tier 3 standards. Further, as 

discussed in Sections V.B and IX.B there are significant challenges associated with 

reducing sulfur below 10 ppm. 

7. Other Provisions

a. Early Credits

The California LEV III program is scheduled to begin at least two model years 

earlier than the federal Tier 3 program.322 The Tier 3 standards begin in MY 2017 for 

vehicles 6,000 lbs GVWR and less, and in MY 2018 for vehicles over 6,000 lbs GVWR. 

As a result, LEV III vehicles sold in California beginning in MY 2015 will be required to 

meet a lower fleet average NMOG+NOX level than the federal fleet will be meeting at 

that time. In addition, the California NMOG+NOX standards will further decline before 

Tier 3 begins, resulting in the gap growing between the current federal program and LEV 

III. 

We are finalizing an early credit program that with minor revisions is as we 

proposed. We have designed the early credit provisions to accomplish three goals: (1) to 

encourage manufacturers to produce a cleaner federal fleet earlier than otherwise 

required; (2) to provide valuable flexibility to the manufacturers to facilitate the 

significant “step down” from the current Tier 2 Bin 5 fleet average required in MY 2016 

to the LEV III-based declining fleet average in MY 2017; and (3) to create an overall Tier 

3 program that although starts later, is equivalent in stringency to the LEV III program 

such that manufacturers will be able to produce a 50-state fleet at the earliest opportunity. 

Commenters were generally supportive of or silent on the early credits program as 

proposed. 

 

322 See California Low-Emission Vehicles (LEV) & GHG 2012 regulations adopted by the State of 

California Air Resources Board, March 22, 2012, Resolution 12-21 incorporating by reference Resolution 

12-11, which was adopted January 26, 2012. Available at 

http://www.arb.ca.gov/regact/2012/leviiighg2012/leviiighg2012.htm (last accessed December 2, 2013).
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The early credit program we are finalizing includes several distinct provisions. 

The first provision allows manufacturers to generate early federal credits against the 

current Tier 2 Bin 5 requirement323 in MYs 2015 and 2016 for vehicles under 6,000 lbs 

GVWR and MYs 2016 and 2017 for vehicles greater than 6,000 lbs GVWR. Early 

credits will only be available to manufacturers that comply under the primary program 

(declining fleet average), not the alternative phase-in approach (Section IV.A.2.c above). 

In order to generate these credits, manufacturers sum the bin specific NMOG and NOX

certification standards for each federally certified Tier 2 vehicle and the bin 

NMOG+NOX standards for any vehicle certified under the Early Tier 3 provision 

described below and calculate an NMOG+ NOX fleet average for the entire 

manufacturers fleet sold in a model year. Credits are based on how far the fleet average 

is below the existing Tier 2 Bin 5 requirement (160 mg/mi total of NMOG and NOX). 

We expect that manufacturers will be able to achieve a fleetwide average below the Tier 

2 Bin 5 level by several means, such as certifying LEV III vehicles either under Tier 2 or 

as Early Tier 3 vehicles under Tier 3 (discussed in the next section) to bin levels lower 

than Tier 2 Bin 5. Our analysis, presented in Section IV.A.5 above and Chapter 1 of the 

RIA, shows that manufacturers could certify many vehicles currently certified to Tier 2 

Bin 5 to a lower bin -- e.g., to Tier 2 Bin 3 or Bin 4 – by simply accepting a relatively 

small reduction in compliance margins. Many manufacturers certify Tier 2 vehicles to 

Tier 2 Bin 5 but also certify the same vehicle to a cleaner emission standard under the 

LEV II program (e.g. ULEV) with only a compliance margin difference. 

We believe that the early credit provision will help us realize both our first and 

second goals presented above. For example, a manufacturer certifying their federal fleet 

to Tier 2 Bin 4 will earn 50 mg/mi of NMOG+ NOX credits per vehicle (i.e., 160 mg/mi 

minus 110 mg/mi), which we believe will encourage manufacturers to certify a cleaner 

federal fleet and provide a reasonable opportunity for credit generation to facilitate the 

“step down” in stringency. 

At the same time, if we allowed manufacturers to generate excessive early credits, 

manufacturers might thereby delay their compliance with the Tier 3 program, and thus 

the harmonization with LEV III, for several years. This would be in direct conflict with 

our third goal of creating a program of equal stringency to the California program as 

early as possible. In order to address this concern, we proposed and are finalizing a 

provision limiting the application of the early Tier 3 credits to the following conditions:

 Early Tier 3 credits generated as described above could be used without 

limitation in MY 2017 on the portion of the fleet entering the Tier 3 program 

in that MY.

 

323 Tier 2 standards are not set in the form of NMOG+NOx. The equivalent Tier 2 Bin 5 fleet average in 

NMOG+ NOX terms is equal to 160 mg/mi (90 mg/mi NMOG + 70 mg/mi NOX).
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 Credits used for compliance in MY 2018 and beyond will be capped at an 

amount equal to the lesser of the manufacturer’s federal credits as calculated 

above or the manufacturer’s LEV III credits scaled up by the ratio of 50-state 

sales to California and LEV III required states sales. This limitation accounts 

for the fact that some LEV III credits may have begun to expire and will no 

longer be eligible as a basis for Tier 3 early credits.

By capping the available federal Tier 3 early credits, we believe that the two 

programs, LEV III and Tier 3 will be at parity in terms of relative stringency starting in 

MY 2018. In addition, because the number of Tier 3 early credits that can be used is 

based on the number of LEV III credits that the manufacturer has generated, there may be 

additional motivation for manufacturers to over-perform in California during the initial 

model years, accelerating emission reduction benefits.

Finally, we are adopting, as proposed, a limitation on the life of Tier 3 early 

credits to 5 years, with no discounting, consistent with the California LEV III program. 

b. Early Tier 3 Compliance

We are finalizing, as proposed, the requirement that manufacturers begin the Tier 

3 program in MY 2017 for vehicles up to 6,000 lbs GVWR and MY 2018 for vehicles 

above 6,000 lbs GVWR under the primary phase-in. The only proposed compliance 

approach available prior to MY 2017 was for manufacturers to continue to certify

vehicles to the existing Tier 2 standards with the opportunity to earn early credits (see 

previous section) that could be used in MY 2017 and later.

Several auto industry commenters suggested additional provisions that could 

facilitate earlier harmonization between Tier 3 and LEV III and streamlining of 

development and certification of vehicle models. Specifically, these commenters 

requested the ability to have vehicles certified to the Tier 3 standards in MYs 2015 and 

2016. They commented that this would allow them to develop, certify and sell a vehicle 

model for all 50 states, reducing the complexity of potentially different federal and 

California requirements in MYs 2015 and 2016. Additionally, commenters noted that the 

Tier 3 program provides more flexibility in the certification bin structure compared with 

the existing Tier 2, providing them additional opportunities to generate early credits.

To address this concern, we are finalizing a provision to allow manufacturers to 

certify to Tier 3 standards starting in MY 2015 as “Early Tier 3” vehicles. Manufacturers 

will have the option to certify their vehicle models to meet the Tier 3 emission 

requirements in MY 2015 and 2016 for all LDVs, LDTs, and MDPVs, which would have 

been required to begin in MY 2017 under the primary program. As an example, a 

manufacturer choosing to certify a vehicle as Early Tier 3 can bring the same vehicle 
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models certified to LEV III standards324 in MY 2015 or 2016 into the Early Tier 3 

program by meeting all the same requirements under the primary Tier 3 schedule. There 

would not be a Tier 3 fleet average requirement for FTP or SFTP in MY 2015 or 2016 

(and 2017 for vehicles over 6,000 lbs GVWR and up to 8,500 and MDPVs) if all the 

same vehicle models certified to LEV III are also certified as the Early Tier 3 vehicles 

meeting the same LEV III emission standards and also the Tier 3 additional requirements 

(high altitude, and cold CO and hydrocarbons). These Early Tier 3 vehicles would 

replace any Tier 2 offering of the vehicle model consistent with the LEV III offering 

replacing the LEV II models. If a manufacturers chooses to certify only a portion of their 

LEV III vehicle models as Early Tier 3 vehicles in a given MY, they will be required to 

meet the LEV III fleet average requirements in that MY for those models certified as 

Early Tier 3 vehicles. All vehicles models not certified as Early Tier 3 vehicles must 

meet all Tier 2 requirements. 

c. Useful Life

The “useful life” of a vehicle is the period of time, in terms of years and miles, 

during which a manufacturer is responsible for the vehicle’s emissions performance. For 

the Tier 3 program, we are finalizing several changes to the existing useful life provisions 

that are appropriate to the new Tier 3 standards described above. 

The auto manufacturing industry has uniformly expressed the desire to produce 

and sell a single national vehicle fleet, including a general ability and willingness of the 

industry to certify their vehicles to a 150,000 mile, 15 year full useful life, as required by

the LEV III program. However, the CAA, written at a time when vehicles did not last as 

long as they do today, precludes EPA from requiring a useful life value longer than 

120,000 miles (and 10 or 11 years, depending on vehicle category and weight) for lighter 

light-duty vehicles (LDVs and LDTs up to 3,750 lbs loaded vehicle weight (LVW) and 

up to 6,000 lbs GVWR (i.e., LDT1s)). 

For heavier light-duty vehicles (i.e., LDT2s, 3s, 4s, as well as MDPVs, 

representing a large fraction of the light-duty fleet), this statutory restriction does not 

apply, and we are finalizing a 150,000 mile, 15 year useful life value, as proposed. For 

the lighter vehicles, we are continuing to apply the 120,000 mile (and 10 or 11 year, as 

applicable) useful life requirement from the Tier 2 program, also as proposed. For these 

lighter vehicles, manufacturers are allowed to choose to certify to either useful life value 

in complying with the fleet average.325 In order for the Tier 3 NMOG+NOX standards to 

represent the same level of stringency regardless of which useful life value manufacturers 

choose, we proposed and are finalizing proportionally lower numerical values (85 percent 

 

324 Including LEV III SFTP requirements

325 CARB has stated that they do not expect to accept vehicles certified under the federal Tier 3 program to 

a 120,000 mile useful life value for California certification, and thus for meeting California’s fleet average 

NMOG+NOX standards.
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of the NMOG+NOX 150,000 mile standards based on a data analysis in Chapter 1 of the 

RIA) for the declining fleet average FTP NMOG+NOX standards when a manufacturer 

chooses the 120,000 mile useful life. A manufacturer choosing the 120,000 mile useful 

life for any vehicle must maintain separate120,000 mile and 150,000 mile useful life fleet 

averages for purposes of FTP NMOG+NOX fleet average compliance. Credits generated 

towards the required fleet averages are not transferable between the two useful life fleet 

averages. 

We proposed that a manufacturer that certifies any vehicle model under the 

120,000 mile provision be required to certify all their LDVs and LDT1s to the 120,000

mile useful life and associated numerically lower FTP NMOG+NOX fleet average 

standard. Comments from the auto industry expressed a concern that this approach 

would be inflexible to manufacturers’ needs and unnecessarily burdensome. We have 

considered these comments, and we believe that the emission benefits of Tier 3 program 

will not be adversely affected if manufacturers are allowed to certify these lighter 

vehicles to the 120,000 mile useful life standards on a test group basis, and therefore we 

are finalizing this approach. Standards for all other pollutants326 and all other test cycles 

such as SFTP remain the same regardless of whether manufacturers choose the 120,000 

mile or the 150,000 mile useful life periods. 

For emission standards other than PM standards (e.g., NMOG+NOX standards), as 

proposed, manufacturers will be required to certify all vehicles to the 150,000 mile useful 

life beginning with the first model year that a vehicle model is certified to the FTP 

NMOG+NOX Bin 70 or lower (other than vehicles not yet required to meet a 150,000 

mile useful life during the program phase in, and vehicles for which a manufacturer has 

the option and chooses to apply the 120,000 mile useful life value). This useful life 

requirement will apply as early as MY 2017. Beginning in MY 2020, all vehicles will 

need to certify to the 150,000 mile useful life for all emissions, regardless of 

NMOG+NOX certification bin, unless they are eligible for, and the manufacturer has 

chosen the 120,000 mile useful life and associated standards. (Note that the timing of the 

requirement to certify on the new test fuel follows the same approach as for the useful life 

requirement for emission standards other than PM standards (i.e., based on the first year a 

model is certified to FTP NMOG+NOX Bin 70 or below) as described in the next 

section.) For FTP and SFTP PM useful life requirements, manufacturers will be required 

to certify to 150,000 mile useful life for PM all vehicles that are included in the 

manufacturer’s phase-in percentage meeting the new PM standards (other than eligible 

vehicles for which a manufacturer chooses to apply the 120,000 miles useful life value).

 

326 PM, CO, and HCHO.
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d. Test Fuels for Exhaust Criteria Emissions Standards

We recognize that test fuels are an important element of a national program. 

Vehicle manufacturers have emphasized in their comments the desire to reduce their test 

burdens by producing one vehicle that is tested on a single test procedure and on a single 

test fuel and that meets both California and federal requirements. Although we have been 

able to reasonably align the Tier 3 program with the LEV III program in most key 

respects, we recognize that the Tier 3 and LEV III test fuels are different, and that there 

may still exist some differences in emissions performance between vehicles tested on the 

two fuels. The largest difference between the two fuels is the Reid Vapor Pressure 

(RVP), and other differences in distillation properties and aromatic levels also exist 

(largely related to differences in actual in-use fuel nationally and in California). We are 

finalizing as proposed the requirement that manufacturers certify vehicles on the new 

Tier 3 E10 test fuels327 beginning with the first model year that a vehicle model is 

certified to the FTP NMOG+NOX Bin 70 or lower.328 This requirement may apply as 

early as MY 2017 for vehicles up to 6000 lbs GVWR and MY 2018 for vehicles greater 

than 6000 lbs GVWR.329 This requirement also applies to vehicles certified at Bin 70 and 

lower that are brought into the Tier 3 program under the Early Tier 3 option described in 

IV.A.7.b above, with the exception of the specific provision allowing the use of LEV III 

fuels discussed below. Beginning in MY 2020, all gasoline-fueled models will need to 

certify on the Tier 3 test fuels for all exhaust emission requirements, regardless of their 

certification bin.330 As discussed in Section IV.A.7.c above, manufacturers must also 

meet the 150,000 mile useful life requirements for NMOG+NOX standards for these same 

vehicles as they are certified to Bin 70 and lower. 

During the transition period from Tier 2 fuel to the new Tier 3 and LEV III E10 

fuels, manufacturers have indicated that they face a substantial workload challenge of 

developing and certifying each vehicle model to the two new fuels simultaneously. We 

recognize this transitional challenge and are including an additional option. We are 

finalizing as proposed an option that vehicles certified in MYs 2015 through 2019 to 

California LEV III standards using California LEV III E10 certification test fuels and test 

procedures can be used for certifying to EPA Tier 2 or Tier 3 exhaust emission standards, 

including PM. A manufacturer may submit LEV III test data on vehicles tested using the 

new LEV III E10 fuels for Tier 2 or Tier 3 certifications. Consistent with existing Tier 2 

policy, EPA may test vehicles certified to Tier 2 standards using LEV III test results on 

 

327 This includes fuels used for cold temperature and high altitude testing and durability requirements. See 

Section IV.F below. 

328 The lower Bins are Bin 0, Bin 20, Bin 30 and Bin 50.

329 Vehicles above 6000 lb GVWR choosing the alternative phase-in schedules described in Section 

IV.A.2.c above generally would begin using the Tier 3 test fuels for MY2019. 

330 Diesel fueled and alternative fueled vehicles will continue to test on the fuels used under the Tier 2 

program except for E85 fueled vehicles, for which we are finalizing new test fuel specifications (see 

Section IV.F below). 
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Tier 2 fuel for confirmatory or in-use exhaust testing. For vehicles certified in MY 2017 

through 2019 to Tier 3 standards using LEV III E10 fuels, EPA will only use LEV III 

E10 fuels for confirmatory and in-use testing (except for high altitude or cold CO and 

hydrocarbons testing, as described below). Vehicles certified to the provisions of Early 

Tier 3 (Section IV.A.7.b above) will be treated the same as Tier 3 vehicles certified in 

MY 2017. For example, for MY 2015 and 2016, EPA will consider Early Tier 3 vehicles 

to be part of the Tier 3 program for purposes of fuel-related testing obligations. We will 

not accept test results using LEV II fuels for Tier 3 vehicle certification, including Early 

Tier 3 certifications, with the exception of the PZEV exhaust carry-over provision 

described below. 

California does not have fuel specifications for high altitude testing or cold CO 

and hydrocarbon testing. For this reason, we are finalizing that for vehicles that 

manufacturers choose to certify using LEV III fuel and test procedures, manufacturers 

must use program-specific federal test fuels to comply with these federal-only

requirements (i.e. Tier 2 vehicles will use Tier 2 fuel and Tier 3 vehicles will use Tier 3 

fuel). Similarly, high altitude and cold CO and hydrocarbon confirmatory and in-use 

testing for these vehicles will be performed on the federal fuel that the manufacturer is 

required to use at certification as specified above regardless of whether LEV III or federal 

fuel is used for other testing. 

We proposed the requirement that after MY 2019, all Tier 3 certification, 

confirmatory and in-use emission testing be required to use only the proposed Tier 3 E15 

test fuel because it was believed to be a worst case fuel for emissions. Because we are 

finalizing Tier 3 E10 test fuels which are very similar as explained above to LEV III E10 

test fuels, and not considered a worst case fuel, we are not finalizing the requirement for 

all testing to be performed on Tier 3 E10 test fuel. Instead, for certifications after MY 

2019, EPA will continue to allow LEV III test results to be submitted for certification to 

Tier 3 standards, consistent with protocol under the Tier 2 program. However, if a 

manufacturer chooses to submit certification results for compliance with Tier 3 standards 

using the LEV III test fuel, then for confirmatory and in-use testing we will hold vehicles 

to the Tier 3 standards while using the Tier 3 fuel in addition to the LEV III test fuel; we 

will not allow new or carry-over certifications using LEV II or Tier 2 certification test 

fuels after MY 2019. CARB has indicated that they will accept Tier 3 test data (on 

federal certification test fuels) to obtain a California certificate as early as MY 2015. In 

this manner manufacturers should be able to avoid compliance testing on more than one 

fuel, since vehicles certified to Interim or Final Tier 3 status using federal certification 

test fuels could also obtain LEV III certification.
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Auto industry commenters noted that the LEV III program provides an allowance 

for manufacturers to carry over PZEV-certified vehicle exhaust data331 from the LEV II 

program into LEV III compliance in MY 2015 through MY 2019. Thus, CARB allows 

these PZEV vehicles to use emission testing results using LEV II fuel (i.e. California 

Phase II test fuel) to meet the LEV III obligations. The commenters suggested that EPA 

allow manufacturers to carry over such PZEV 150,000 mile useful life exhaust emission 

data to meet the Tier 3 standards. We agree that this approach is appropriate during the 

transition, and we are finalizing this provision for MY 2015 through MY 2019, including 

allowing Early Tier 3 compliance at the Bin 30 level as a combined NMOG + NOX 

standard. EPA will hold vehicles certified using this provision to the Tier 3 emission 

requirements when they are tested on the LEV II fuel for confirmatory and in-use. 

Compliance testing of these vehicles for all other Tier 3 obligations (i.e., high-altitude 

testing and Cold CO and hydrocarbons testing) must be performed using Tier 3 fuel, and 

these vehicles will be required to meet the Tier 3 standards for Bin 30. 

e. High Altitude Requirements

FTP emission standards are historically designed to be applicable at all altitudes. 

Under Tier 2, the same FTP emission bin standards applied to vehicles tested at both low 

and high-altitude. However, fundamental physical challenges exist at high altitude 

resulting in typically higher emissions during cold starts compared with starts at lower 

altitudes (i.e., sea level), and these challenges become more pronounced as emission 

standards become more stringent. This expected increase in emissions is primarily due to 

the lower air density at higher altitudes. Due to the lower air density, the needed volume 

of the hot combustion exhaust required to quickly heat the catalyst in the first minute 

after a cold start is reduced. As a result, catalyst light-off is delayed and cold start 

emissions can increase. Vehicles under the Tier 2 program typically have had sufficient 

compliance margins to absorb this increase in emissions during testing under highaltitude conditions. However, given the extremely low standards we are finalizing in Tier 

3, manufacturers will have less compliance margin with which to address the issue. 

Under the Tier 3 program, we expect that the emission control technologies 

selected for low altitude performance will also provide very significant emission control 

at high altitude.332 However, as explained above, unique emission challenges exist with 

operation at higher altitude, often requiring manufacturers to design their emission 

controls specifically for higher altitude. 

We do not believe that the impact of the fairly small fraction of overall U.S. 

driving that occurs in high altitude locations warrants a requirement for additional 

 

331 California’s PZEV exhaust standards are the same as their SULEV standards and the Tier 3 Bin 30, and 

are certified to a 150,000 mile useful life. 

332 High-altitude conditions means a test altitude of 1,620 meters (5,315 feet). Low altitude conditions 

means a test altitude less than 549 meters (1,800 feet).
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technologies to be applied specifically for high-altitude conditions. To avoid requiring 

manufacturers to use special high-altitude emission control technologies, we are allowing 

manufacturers limited relief for certification testing at high altitude, as proposed. 

Specifically, for sea-level certifications to Tier 3 Bins 20, 30, and 50, a manufacturer 

could comply with the next less-stringent bin for testing at high altitude. For example, a 

manufacturer can certify to Bin 50 for testing at high altitude versus Bin 30 at sea level). 

For vehicles certified at sea level to Bins 70 and 125, manufacturers can comply with 

standards 35 mg/mi higher (e.g., 105 mg/mi and 160 mg/mi, respectively. We are 

providing no high altitude relief for vehicles certified to Bin 160. This high altitude relief 

provision applies to all Final Tier 3 vehicles for the duration of the Tier 3 program. 

For intermediate altitudes that fall between the specified low and high altitude test 

conditions, the emission performance should continue to be representative of the controls 

implemented to meet standards at the required altitude test conditions, consistent with 

Tier 2 protocol. Any deviation in the use of these controls at the intermediate altitudes 

may be considered an AECD that must be reported by the manufacturer and justified as 

not being a defeat device333.

Table IV-9 presents the Tier 3 high altitude standards.

Table IV-9 Tier 3 High Altitude Standards

Bin Sea Level FTP Standard

(mg/mi NMOG+NOX)

Altitude FTP Standard

(mg/mi NMOG+NOX)

Bin 160 160 160

Bin 125 125 160

Bin 70 70 105

Bin 50 50 70

Bin 30 30 50

Bin 20 20 30

f. Highway Test Standards

Sustained high-speed operation can result in NOX emissions that may not be 

represented on either the FTP or SFTP cycles. Although we are not aware of any serious 

issues with this mode of operation with current Tier 2 vehicles, we are interested in 

 

333 §86.1809-12 Prohibition of defeat devices
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preventing increases in these NOX emissions as manufacturers develop new or improved 

engine and emission control technologies. 

For this reason, we are finalizing, as proposed, a provision that the Tier 3 FTP 

NMOG + NOX standards above also apply on the Highway Fuel Economy Test (HFET), 

which is performed as a part of GHG and Fuel Economy compliance testing. Thus, the 

Tier 3 FTP NMOG+NOX standard for the bin at which a manufacturer has chosen to 

certify a vehicle will also apply on the HFET test. For example, if a manufacturer 

certifies a vehicle to Bin 70, the vehicle’s NMOG+NOX performance over the HFET 

could not exceed 70 mg/mi. Manufacturers will simply need to ensure that the same 

emission control strategies implemented for the FTP and SFTP cycles are also effective 

during the highway test cycle. We believe that this requirement will not require 

manufacturers to take any unique technological action, will not add technology costs, and 

will not add significantly to the certification burden. 

g. Interim 4,000 Mile SFTP Standards

During the period of the declining NMOG+ NOX standards, we are finalizing the 

proposed requirement that interim Tier 3 vehicles meet 4,000 mile SFTP standards, 

consistent with the existing Tier 2 and LEV II program requirements. The 4,000 mile 

standards apply to each vehicle model individually and to each component of the SFTP 

composite cycle. This approach is designed to prevent excessive emission levels from 

individual vehicle models being masked by the averaging of the manufacturer’s fleet 

emissions. Similarly, this approach also prevents poor performance on a single cycle of 

the SFTP. We believe it is appropriate to require any individual Interim Tier 3 vehicle to 

at a minimum meet the existing requirements under the Tier 2 and LEV II programs. 

Table IV-10 below presents the 4,000 mile SFTP standards for interim Tier 3 vehicles.

Table IV-10 4,000 Mile SFTP Exhaust Standards for Interim Tier 3 Vehicles 

(grams/mile)

Vehicle Category US06

NMOG+NOX

US06

CO

SC03

NMOG+NOX

SC03

CO

LDV/LDT1 0.14 8.0 0.20 2.7

LDT2 0.25 10.5 0.27 3.5

LDT3 0.4 10.5 0.31 3.5

LDT4 0.6 11.8 0.44 4.0

We believe that vehicles considered to be Final Tier 3 vehicles (i.e., they meet the 

Tier 3 PM requirements, specifically the stringent SFTP PM standards) will have 

sufficiently robust designs that the 4,000 mile SFTP standards will no longer be 

necessary and so will not apply to those vehicles. Additionally, once the program reaches 
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the fully phased-in fleet average composite standard of 50 mg/mi in 2025, high SFTP 

emissions even on a limited portion of a manufacturer’s fleet should be effectively 

mitigated, and the 4,000 mile SFTP standards will no longer apply. 

h. Phase-in Schedule

As proposed, the major provisions of the Tier 3 program phase in based on model 

year and on the emission levels to which manufacturers certify their vehicles. As 

described in Section IV.A.3, under the Tier 3 program, manufacturers are required to 

certify each vehicle model to an FTP bin, which is then used to calculate the 

NMOG+NOX fleet average of all of its Tier 3 vehicles. Manufacturers must also 

determine the SFTP levels of each model and calculate the NMOG+NOX fleet average 

for the SFTP requirements as described in Section IV.A.4. These separate FTP and SFTP 

fleet average calculations satisfy one aspect of certification under the Tier 3 program, 

specifically the standards associated with each model year.

As described in Sections IV.A.7.c and IV.A.7.d above, the longer (150,000 mile) 

useful life value, as applicable, and the new Tier 3 test fuel for exhaust testing will be 

implemented as manufacturers certify vehicles to more stringent NMOG+NOX standards, 

with the threshold to implement both of these provisions being Bin 70. Beginning in MY 

2017, any vehicle certified to Bin 70 or lower will be required to be certified on Tier 3 

test fuel. In addition, any vehicle certified to Bin 70 or lower that is required to meet the 

longer 150,000 mile useful life will be required to do so at that point. Independent of the 

Tier 3 test fuel phase in schedule, the 150,000 mile useful life for PM standards will be 

required when the vehicle is certified to the new Tier 3 PM standards as described below 

in the PM phase-in schedules. Beginning in MY 2020, all gasoline-fueled vehicles will 

be required to be certified for exhaust emissions on the Tier 3 test fuel, regardless of their 

certification bin or applicable useful life.

Manufacturers must also comply with more stringent PM standards on a percent 

phase-in schedule. Compliance with the PM standards, which is consistent with the 

CARB LEV III program, is independent of the NMOG+NOX fleet average requirements 

described above. The PM emission standards for FTP and SFTP described in Section 

IV.A.3 and 4 respectively will be implemented as a percent phase-in requirement as 

described below under a primary phase-in schedule or under an optional phase-in 

schedule.

Vehicle models that a manufacturer certifies to a Tier 3 NMOG+NOX bin, that 

meet the requirements of the PM phase-in schedule, and that comply with the other Tier 3 

requirements (i.e., 150,000 mile useful life and Tier 3 test fuel, as applicable) will be 

considered “Final Tier 3” compliant vehicles. All other vehicles certified to Tier 3 bins 

but not yet meeting the PM and other Tier 3 requirements will be considered “Interim 

Tier 3” compliant vehicles. At the completion of the percent phase-in period for PM 

(2021 for the primary PM phase-in schedule and 2022 for the optional PM phase-in 
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schedule, as described below), 100 percent of vehicles will need to meet all of the Tier 3 

requirements and will be considered Final Tier 3 vehicles. 

As proposed, for the PM requirements, each model year manufacturers must meet 

either the primary PM percent phase-in or the optional PM phase-in as described in the 

following subsections. The primary percent PM phase-in schedule is composed of fixed 

annual minimum phase-in percentages that we expect most manufacturers to choose in 

order to comply with the Tier 3 requirements. The optional PM phase-in schedule 

provides additional flexibility for manufacturers with too few product offerings to allow 

for a sufficiently gradual transition into the Final Tier 3 requirements, as described 

below. In either case, Interim Tier 3 vehicles not yet meeting the Tier 3 PM standards 

must at a minimum meet the Tier 2 PM full useful life FTP PM standard of 10 mg/mi and 

the SFTP PM weighted composite standard of 70 mg/mi. 

i. Primary PM Percent Phase-In Schedule

It is important to note that the percent phase-in of the new Tier 3 PM standards 

and the declining fleet average NMOG+NOX standards that we are finalizing are separate 

and independent elements of the Tier 3 program. “Phase-in” in the context of Tier 3 PM 

standards means the fraction of a manufacturer’s fleet that is required to meet the new 

Tier 3 PM standards in a given model year. We expect that manufacturer fleets may

consist of a mix of vehicle models certified to Tier 2, LEV II, LEV III and Tier 3 

standards throughout the percent phase-in period. 

As discussed above, vehicles originally certified to Tier 2, LEV II, and LEV III 

may be carried over into the Tier 3 program as Interim Tier 3 vehicles. A vehicle will be 

considered a Final Tier 3 vehicle when it is certified to one of the Tier 3 bins, meets the 

new Tier 3 PM standards for FTP (3mg/mi) and US06 (10 or 6 mg/mi), certifies to the 

150,000 useful life value (as applicable), and certifies on the new Tier 3 test fuel. Table 

IV-11 below presents the PM phase-in schedule for Final Tier 3 vehicles.

Table IV-11 PM Phase-in Schedule for Final Tier 3 Vehicles

Model Year 2017 2018 2019 2020 2021 2022 and 

later

Manufacturer’s

Fleet (%)

20 a20 40 70 100 100

Vehicle Types

≤ 6,000 lbs 

GVWR

All vehicles ≤ 8,500 lbs GVWR and MDPVs

a Manufacturers comply in MY 2017 with 20 percent of their LDV and LDT fleet under 6,000 lbs GVWR, 

or alternatively with 10 percent of their total LDV, LDT, and MDPV fleet Optional PM Phase-in
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The PM percent-of-sales phase-in schedule described above will allow 

manufacturers with multiple vehicle models to plan the phase-in of those models based 

on anticipated volumes of each vehicle model. However, manufacturers certifying only a 

few vehicle models might not benefit from this schedule. This is because, in order to 

satisfy the phase-in schedule percentages, they may have to over-comply with the 

required percentages earlier than will a manufacturer with many vehicle models available 

for the phase-in. 

For instance, a manufacturer with only two models that each equally account for 

50 percent of their sales will be required to introduce (at least) one of the models in MY 

2017 to meet the PM phase-in requirement of 20 percent in the first year. Because it 

represents 50 percent of the manufacturer’s sales, this model will then also meet the 

requirements for MY 2018 (20 percent) and MY 2019 (40 percent). To meet the MY 

2020 requirement of 70 percent of sales, however, the manufacturer will need to 

introduce the second Tier 3 vehicle that year. Thus the manufacturer will have 

introduced 100 percent of its Tier 3 models one year earlier than required of a 

manufacturer that is able to delay the final 30 percent of its fleet until MY 2021 (by

distributing its models over the entire phase-in period).

To provide for more equivalent phasing in of the PM requirements among all 

manufacturers in the early years of the program, we are finalizing, as proposed, an 

optional “indexed” PM phase-in schedule that can be used by a manufacturer to meet its 

PM percent phase-in requirements. A manufacturer that exceeds the phase-in 

requirements in any given year will be allowed to, in effect, offset some of the phase-in 

requirements in a later model year. The optional phase-in schedule will be acceptable if 

it passes a mathematical test. The mathematical test is designed to provide manufacturers 

a benefit from certifying to the standards at higher volumes than they are obligated to 

under the normal phase-in schedule, while ensuring that significant numbers of vehicles 

are meeting the new Tier 3 requirements during each year of the optional phase-in 

schedule. In this approach, manufacturers weight the earlier years by multiplying their 

percent phase-in by the number of years prior to MY 2022 (i.e., the second year of the 

100 percent phase-in requirement). 

The mathematical equation for applying the optional PM phase-in is as follows:

(5 x APP2017) + (4 x APP2018) + (3 x APP2019) + (2 x APP2020) + (1 x APP2021) 

≥540, where APP is the actual phase-in percentage for the referenced model year. 

The sum of the calculation must be greater than or equal to 540, which is the 

result when the optional phase-in equation is applied to the primary percent phase-in 

schedule (i.e., 5 x 20% + 4 x 20% + 3 x 40% + 2 x 70% + 1 x 100% = 540).

Applying the optional PM phase-in equation to the hypothetical manufacturer in 

the example above, the manufacturer can postpone its model introductions by one year 
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each, to MY 2018 and MY 2021. Its calculation is (5 x 0% + 4 x 50% + 3 x 50% + 2 x 

50% + 1 x 100% = 550, and thus the phase-in is acceptable. 

i. In-use Standards 

i. NMOG + NOX

The Tier 3 emission standards will require a substantial migration of emission 

control technology historically used only on a small percent of the fleet and typically 

limited to smaller vehicles and engines. While we believe that these technologies can 

generally be used on any vehicle and are applicable to the entire fleet, manufacturers 

have less experience with the in-use performance of these technologies across the fleet. 

For example, technologies that accelerate catalyst warm-up such as catalyst location close 

to the engine exhaust ports and other advanced thermal management approaches will be 

new to certain vehicle types, particularly larger vehicles (i.e., LDT3/4s), which have 

historically not relied on these technologies to meet emission standards.

As proposed, to help manufacturers address the lack of in-use experience and 

associated challenges with the expanded introduction of these technologies, particularly 

in the larger vehicles, we are finalizing temporarily-relaxed in-use NMOG+NOX

standards that will apply to all vehicles certified to Bins 70 and cleaner as Interim or 

Final Tier 3 vehicles. The in-use standards will apply during the entire percent phase-in 

period (i.e., through MY 2021). The in-use standards are 40 percent less stringent than 

the certification standards, providing a significant but reasonable temporary cushion for 

the uncertainties associated with new technologies (or new applications of existing 

technologies) over the life of the vehicles.

 The in-use NMOG + NOX standards are shown in Table IV-12. 

Table IV-12 FTP In-Use Standards for Light Duty Vehicles and MDPVs (mg/mi)

Bin NMOG+NOX

(mg/mi)

Bin 160 160

Bin 125 125

Bin 70 98

Bin 50 70

Bin 30 42

Bin 20 28
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ii. PM

As with the NMOG+NOX standards, the introduction of new emission control 

technologies or new applications of existing technologies (e.g., GDI, turbocharging, 

downsized engines) will create significant uncertainties for manufacturers about in-use 

performance over the vehicle’s useful life. We are finalizing as proposed a temporary inuse FTP standard for PM of 6 mg/mi for all light duty vehicles certified to the Tier 3 full 

useful life 3 mg/mi standard. Since the Tier 3 FTP PM standard has a percent phase-in 

schedule spread over several years, starting in 2017 with full phase-in completed in 2022, 

we are finalizing the requirement that the in-use standard apply to all vehicles certified to 

the new PM standards during the entire percent phase-in period (i.e., through MY 2021).

We also proposed temporarily-relaxed in-use US06 PM standards. As described 

in Section IV.A.4.b above, we are finalizing an in-use US06 PM standard of 10 mg/mi 

for the intermediate years of the program (MYs 2019 through 2023) in response to 

industry concerns about emissions variability as the new standards become effective. 

j. FFVs

Because of the physical and chemical differences in how emissions are generated 

and controlled between vehicles operating on different blends of gasoline and ethanol, 

manufacturers of vehicles designed for high-percentage blends of ethanol (usually called 

Flexible Fuel Vehicles, or FFVs) may face unique compliance challenges under the Tier 

3 program. Historically, under the Tier 2 program, FFVs have only been required to meet 

all Tier 2 emission standards, FTP and SFTP, while operating on gasoline (E0); when 

operating on the alternative fuel (generally this means a blend that is nominally 85 

percent ethanol, or E85), they have only been required to meet the FTP emission 

standards. 

However, E85 use may rise considerably in the future as ethanol use increases in 

response to the Renewable Fuels Standards (RFS). Thus, as the Tier 3 program is 

implemented, it is increasingly important that FFVs maintain their emission performance 

when operating on E85 across different operating conditions.

We believe that at standard test conditions, requiring manufacturers to meet the 

Tier 3 standards on any blend of gasoline and ethanol will not be significantly more 

challenging technologically than compliance on lower ethanol blends, including the E10 

Tier 3 test fuel we are adopting. We are thus finalizing, as proposed, the requirement 

that in addition to complying with the Tier 3 requirements when operating on Tier 3 test 

fuel, FFVs also comply with both the FTP and the SFTP emission standards when 

operating on E85. This includes the requirement to meet emission standards for both Tier 

3 test fuel and E85 for the FTP, highway test, and SFTP emission standards at standard 

test temperatures (i.e., 68 °F to 86 °F). Since FFVs can operate on any blend of gasoline 

and ethanol (up to a nominal 85 percent ethanol), the emission requirements apply to 

operation at all levels of the alternative fuel that can be achieved with commercially 
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available fuels. However, for exhaust emission compliance demonstration purposes, we 

will test on Tier 3 test fuel and on fuel with the highest available ethanol content. 

k. Credit for Direct Ozone Reduction (DOR) Technology

Since the late 1990s, technologies have been commercialized with which vehicles 

can remove ozone from the air that flows over the vehicle’s coolant radiator. In such 

direct ozone reduction (DOR) technology, a catalytic coating on the radiator is designed 

to convert ambient ozone into gaseous oxygen, as a way of addressing the air quality

concerns about ozone. Detailed technical analyses for the California LEV II and the 

federal Tier 2 programs showed that when properly designed these systems can remove 

sufficient ozone from the air to be equivalent to a quantifiable reduction in tailpipe 

NMOG emissions. In the earlier programs, both California and EPA provided 

methodologies through which a manufacturer could demonstrate the capability and 

effectiveness of the ozone-reducing technology and be granted an NMOG credit. A small 

number of vehicle models with DOR applications received credit under the LEV II 

program; no manufacturer formally applied for credits under the federal Tier 2 program.

Some manufacturers have expressed an interest in the continued availability of a 

DOR credit as a part of their potential LEV III and Tier 3 compliance strategies. EPA 

believes that when a DOR system is shown to be effective in reducing ozone, a credit 

toward Tier 3 compliance is warranted. We are finalizing a provision, as proposed, that 

manufacturers following the California methodology for demonstrating effectiveness and 

calculating a appropriate credit for a DOR system be granted a specific credit toward the 

NMOG portion of the NMOG+NOX standard.334 As with the California program, such a 

credit may not exceed 5 mg/mi NMOG. 

l. Credit for Adopting a 150,000-Mile Emissions Warranty

Under the Tier 3 standards, manufacturers are expected to design their emission 

control systems to continue to operate effectively for a useful life of 150,000 miles 

(120,000 miles for some smaller vehicles). However, manufacturers are only required to 

replace failed emission control components or systems on customers’ vehicles for a 

limited time period, specified in the Clean Air Act (80,000 miles/8 years for key emission 

control components). EPA believes that voluntary extension of this warranty obligation 

by manufacturers would provide additional emission reductions by helping ensure that 

controls continue to operate effectively in actual operation through the full life of the 

vehicle. 

We are finalizing as proposed that a manufacturer providing its customers with a 

robust emission control system warranty of 15 years or 150,000 miles be eligible for a 

 

334 EPA is incorporating the CARB DOR methodology by reference. 
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modest credit of 5 mg/mi NMOG+NOX.

335

 Because of the significant liability that 

manufacturers would be accepting, we do not expect that the use of this credit 

opportunity will be widespread. However, based on our modeling of the expected 

deterioration of the emissions of future Tier 3 vehicles absent repair/replacement of failed 

emission controls, we anticipate that the value to the environment of long emissions 

warranties in terms of reduced real-world emissions would significantly exceed the 5 

mg/mi NMOG+NOX credit.336

We will use the same criteria for approving such a credit as does the parallel 

California program.337 Thus, in addition to committing to customers that failing emission 

controls will be repaired or replaced for 15 years/150,000 miles, manufacturers will also 

need to accept the liability that in the event that a specific emissions control device fails 

on greater than 4 percent of a vehicle model’s production, they will recall the entire 

production of that model for repair. 

m. Averaging, Banking, and Trading of Credits

We proposed and are finalizing an averaging, banking, and trading (ABT) 

program similar to those that have historically been a part of most EPA emission control 

programs. For the Tier 3 final rule, the ABT program is consistent with the other Tier 3 

program elements, the heavy duty exhaust emission standards and the evaporative 

emission standards programs, with the only exception being credit life during the longer 

phase in for the light duty program as described below. The ABT program is intended to 

provide an opportunity for manufacturers to deploy their Tier 3 vehicle models more 

efficiently, especially during the transition years, and to avoid excessive delays in the

necessary technological improvements across the fleet. We have designed the Tier 3 

ABT program to provide for credits to be generated by certifying vehicles that perform 

better than the fleet-average NMOG+NOX standards. These credits may be used within a 

company to offset vehicles that perform worse than the standards, they may be banked 

for later use, or they may be traded to other manufacturers. 

We are also finalizing limitations on the use of credits for the light-duty fleet. We 

proposed that Tier 3 credits expire after 5 model years following the model year they are 

generated and solicited comment on the Tier 3 credit life. In communications regarding 

the proposed rule, representatives of the auto industry expressed to EPA that the value of 

the ABT program during the MY 2017-2025 phase-in of the primary program would be 

 

335 Manufacturers choosing to comply with the standards for a 120,000 mile useful life for their LDVs and 

LDT1s are not eligible for this extended warranty credit for those vehicles.

336 Beardsley, M, et al. (2013, February). Updates to MOVES for the Tier 3 NPRM. Memorandum to the 

docket.

337 EPA is incorporating the CARB extended emission warranty provisions by reference.
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improved if credits had a longer credit life.338 We determined that, with certain 

restrictions, Tier 3 credit life can be temporarily extended with no adverse impacts on the 

overall emission reductions of the program. Specifically, we are finalizing a credit life of 

8 years for credits generated in MYs 2017-2022 for the FTP and SFTP NMOG+NOX

fleet average standards for the primary program only. For the heavier light-duty vehicles, 

the 8-year credit life begins for credits generated in MY 2018. Note that, as proposed, 

credits generated under the Early Tier 3 Credit provision (Section IV.A.7.a) are limited to 

5-year life, and are not affected by the longer credit life. 

For credits generated in MYs 2023-2025, the credit life declines by one year of 

credit life annually, with credit life stabilizing at 5 years for credits generated in MYs 

2025 and later. That is, credits generated in MY 2023 have a 7-year life, in MY 2024 a 

6-year life, and in MY 2025 and later a 5-year life. However, while credits can be 

generated, banked, and used internally for the extended time periods, credits cannot be 

traded to other manufacturers after 5 years.

After considering the views expressed by manufacturers as well as the 

implementation schedules of this Tier 3 rule and the 2017 light-duty GHG rule, we 

believe that the temporary up-to-8-year credit life available to manufacturers during the 

phase-in period provides substantial flexibility to address manufacturer uncertainties 

about future technology development and product planning during implementation of the 

Tier 3 program. We also believe this longer credit life provision will alleviate most if not 

all concerns expressed by manufacturers with respect to the challenges they may

encounter by simultaneous implementation of the two programs.

As proposed, we are finalizing a provision for a manufacturer to create a credit 

deficit, at certification or at the end of the production year, if its fleet average emissions 

exceed the standard. A manufacturer would be required to use all of its banked credits, if 

any, before creating a credit deficit. A credit deficit would need to be resolved before the 

fourth model year after the deficit was created; that is, a manufacturer may not maintain a 

credit deficit more than 3 consecutive model years. 

n. Tier 3 Transitional Emissions Bins

During the development of the proposed rule and in their comments, 

manufacturers pointed out that they may continue to produce some vehicles as late as MY 

2019 that could be certified to Tier 2 Bin 3 or Bin 4 standards. In order to provide 

manufacturers flexibility in meeting the fleet average standards and to further facilitate 

the transition, we will allow manufacturers to certify to the combined NMOG+NOX

levels of these Tier 2 bins through MY 2019. We are finalizing two transitional Tier 3 

bins, Bin 110 and Bin 85, that have FTP NMOG+NOX standards of 110 mg/mi and 85 

 

338 Passavant, G. (January2014), Meetings with Chrysler – Tier 3 NPRM Lead Time and ABT, 

Memorandum to Docket. 
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mg/mi, respectively (i.e., the sum of the NMOG and NOX values from the Tier 2 bins). 

The associated FTP standards for CO, PM, and HCHO corresponding to these bins are 

identical to those for vehicles certified to the Tier 3 Bin 125. Tier 3 SFTP standards will 

apply to these vehicles, and these vehicles will be included in the Tier 3 PM percent 

phase-in calculations. 

o. Compliance Demonstration

In general, we are finalizing requirements that manufacturers demonstrate 

compliance with the Tier 3 light-duty vehicle emission standards in a very similar manner 

to existing Tier 2 vehicle compliance (see §86.1860 of the regulatory language). 

However, for Tier 3, manufacturers must calculate their compliance with the fleet 

average standards and percent phase-in standards based on annual nationwide sales, 

including sales in California and Clean Air Act Section 177 states. We believe that this 

approach represents another step toward achieving the goal of an effectively nationwide 

program as early as possible, which has been a basic principle in EPA’s development of 

this program and broadly supported by vehicle manufacturers. We also believe that 

basing compliance on nationwide sales may reduce the need for manufacturers to project 

future sales and track past years’ sales in a disaggregated way. Because the Tier 3 

provisions become increasingly consistent with LEV III provisions as the Tier 3 program 

phases in, we believe that any disproportionate impacts of different mixes of vehicles in 

different states are unlikely to occur. 

This nationwide compliance calculation approach applies to vehicles as they

become subject to the Tier 3 provisions, either the declining fleet-average NMOG+NOX

curves or the percent phase-in PM standards. Were any manufacturer to choose to use 

the alternative FTP and SFTP phase-ins, which are not a part of the LEV III program, the 

manufacturer would not include sales in California or in the Section 177 states in its 

compliance calculations. 

B. Tailpipe Emissions Standards for Heavy-Duty Vehicles 

1. Overview and Scope of Vehicles Regulated 

After considering the comments we received, we are adopting the Tier 3 exhaust 

emissions standards that we proposed for chassis-certified heavy-duty vehicles (HDVs) 

between 8501 and 14,000 lbs gross vehicle weight rating (GVWR). Vehicles in this 

GVWR range are often referred to as Class 2b (8501-10,000 lbs) and Class 3 (10,001-

14,000 lbs) vehicles, and are typically full-size pickup trucks and work vans certified as 

complete vehicles.339 Medium-duty passenger vehicles (MDPVs), although in the Class 

 

339 40 CFR 86.1803-01 defines HDVs to also include motor vehicles at or below 

8,500 lbs GVWR that have a vehicle curb weight of more than 6,000 lbs or a basic 
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2b GVWR range, are subject to Tier 3 standards discussed in Section IV.A. To a large 

extent, we are also adopting the Tier 3 certification testing and compliance provisions 

that we proposed for HDVs. There are, however, a number of improvements we are 

making in response to comments, as discussed in detail below.

The Tier 3 program for HDVs will bring substantial reductions in harmful 

emissions from this large fleet of work trucks and vans, a fleet that is used extensively on 

every part of the nation’s highway, rural, and urban roadway system. The fully-phased in 

Tier 3 standards levels for non-methane organic gas (NMOG) plus oxides of nitrogen 

(NOX), and for particulate matter (PM), are on the order of 60 percent lower than the 

current standards levels.

We proposed to require that diesel-fueled Class 2b and 3 complete vehicles, like 

their gasoline-fueled counterparts, be certified to the Tier 3 standards on the chassis test; 

we also proposed to include these vehicles in the Tier 3 HDV averaging, banking, and 

trading (ABT) program. Currently only gasoline-fueled Class 2b/3 complete HDVs are 

required to chassis certify.

The International Council for Clean Transportation (ICCT) provided comments in 

support of this requirement, arguing that it is needed to stop manufacturers from making 

trucks marginally above 8500 lbs GVWR to avoid light-duty emission standards. The 

Truck and Engine Manufacturers Association (EMA) opposed mandatory chassis 

certification for any class of engines or vehicles over 8500 lbs GVWR, arguing that the 

existing flexibility is needed to minimize unnecessary costs and certification burdens. 

EMA commented that, at a minimum, EPA should maintain optional certification of 

diesel engines used in complete Class 3 vehicles. In their joint comments, the Alliance of 

Automobile Manufacturers and the Association of Global Automakers also requested that 

EPA retain the option for complete Class 3 diesel vehicles and engines, arguing that 

otherwise manufacturers may be required to dual certify vehicle models that include 

variants both under and over 14,000 lbs.

We are sensitive to this issue but remain concerned that the fleet average standard 

program we are finalizing would not work well if a major fleet component, such as 

complete Class 3 diesel trucks, can be left in or taken out of the fleet calculation based on 

what each manufacturer considers to be most advantageous. We believe the resulting 

competitive issues and uncertainties would be problematic, given the wide variance in 

gasoline/diesel HDV sales among the manufacturers, our provision for averaging across 

each manufacturers’ entire Class 2b/3 fleet, and the overwhelming preponderance of 

 

vehicle frontal area in excess of 45 square feet, and these vehicles will also be subject to 

the Tier 3 standards and other provisions applicable to Class 2b vehicles discussed in this 

section.
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diesels in the Class 3 market. It would also create uncertainties in the Tier 3 

environmental benefits, given the pronounced difference between these Tier 3 standards 

and the heavy-duty diesel engine standards we set 13 years ago, which we expect to 

remain in effect for the foreseeable future. 

As a result, we are finalizing these provisions as proposed, except that we are 

providing that manufacturers, instead of certifying complete diesel Class 3 HDVs, may

install diesel engines that have been engine-certified for any model year that the engine 

family has less than half of its sales being installed in such non-chassis-certified complete 

Class 3 vehicles. For example, if a company has a certified diesel engine family with 

10,001 sales in MY 2020, up to 5,000 of those engines may be installed in complete 

Class 3 HDVs that are not chassis-certified for exhaust emissions. This provision is 

intended to help address manufacturers’ concern about dual certification, while at the 

same time ensuring a coherent fleetwide standards regimen in this vehicle class. It also 

better harmonizes with California’s low-emission vehicle (LEV) III program which does 

not mandate chassis certification for diesel Class 3 vehicles. By only allowing enginecertified vehicles in the case of engines that are primarily produced for other purposes, 

we believe this approach adequately guards against potential abuse. In the case of 

complete diesel Class 3 HDVs produced by a company other than the engine certifier, the 

responsibility for ensuring the sales limit is not exceeded remains with the vehicle 

manufacturer, who will need to coordinate with the engine supplier to ensure compliance.

Manufacturers of incomplete HDVs that are sold to secondary manufacturers for 

subsequent completion (less than 10 percent of the Class 2b and 3 U.S. market) are also 

allowed under existing EPA regulations to certify via either the chassis or engine test, and 

those who choose to chassis-certify in the future will be subject to Tier 3 requirements. 

We asked for comment on mandating chassis certification of incomplete Class 2b and 3 

vehicles, noting that California’s LEV III program includes such a requirement for Class 

2b. Commenters expressed opposition to this extension of mandatory chassis 

certification, despite their general support for harmonization with LEV III; as a result, we 

are not mandating chassis certification for any incomplete HDVs.

The key elements of the Tier 3 program for HDVs parallel those for passenger 

cars and light-duty trucks (LDTs), with adjustments in standards levels, emissions test 

requirements, and implementation schedules, appropriate to this sector. These key

elements include:

 a combined NMOG+NOX declining fleet average standard beginning in 2018 and 

reaching the final, fully phased-in level in 2022, 

 creation of a bin structure for standards, including standards for carbon monoxide 

(CO) and formaldehyde,

 PM standards phasing in separately on a percent-of-sales basis, 
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 changes to the test fuel for gasoline- and ethanol-fueled vehicles, 

 extension of the regulatory useful life to 150,000 miles,

 a new requirement to meet standards over the supplemental federal test procedure 

(SFTP) that addresses real-world driving modes not well-represented by the federal 

test procedure (FTP) cycle alone, and

 special flexibility provisions for small businesses and small volume manufacturers 

described in Section IV.G.

As in the light-duty Tier 3 program, we have put a strong emphasis on 

coordinating HDV Tier 3 program elements with California’s LEV III program for Class 

2b and 3 vehicles, referred to in LEV III as medium-duty vehicles (MDVs). The goal is 

to create a coordinated “national program” in which California would accept compliance 

with Tier 3 standards as sufficient to also satisfy LEV III requirements, thus allowing 

manufacturers to comply nationwide by marketing a single vehicle fleet. As part of this 

effort, we proposed that manufacturers of Tier 3 HDVs calculate compliance with the 

fleet average standards and percent phase-in standards based on annual nationwide sales, 

including sales in California and in states implementing California standards under Clean 

Air Act section 177. Commenters expressed emphatic support for this approach and we 

are finalizing it as a key element of the Tier 3 program.

2. HDV Exhaust Emissions Standards

a. Bin Standards

Manufacturers will certify HDVs to Tier 3 requirements by having them meet the

standards for NMOG+NOx, PM, CO and formaldehyde for one of the bins listed in Table 

IV-13. Manufacturers choose bins for their vehicles based on their product plans and 

corporate strategy for compliance with the fleet average standards discussed in Section 

IV.B.2.b, and once a vehicle’s bin is designated, those bin standards apply throughout its 

useful life. Because the fleet average standards become more stringent over time, the bin 

mix will gradually shift from higher to lower bins. 

As in the past, there are numerically higher standards levels for Class 3 vehicles 

than for Class 2b vehicles, reflective of the added challenge in reducing per-mile 

emissions from large work trucks designed to carry and tow heavier loads. Also, the 

standards levels for both Class 2b and Class 3 HDVs are significantly higher than those 

being adopted for light-duty trucks due to marked differences in vehicle size and 

capability, and to our requirement to test HDVs in a loaded condition (at the adjusted 

loaded vehicle weight (ALVW)). By conducting emissions testing with loaded vehicles, 

the heavy-duty program ensures that emissions controls are effective when these vehicles 

are performing one of their core functions: hauling heavy loads. This is a key difference 

between the heavy-duty and light-duty truck programs. The bin structure and standards 
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levels are consistent with those in California’s LEV III program. We requested comment 

on the usefulness of creating additional bins between Bin 0 and the next lowest bin in 

each vehicle class, as a means of encouraging clean technologies and adding flexibility, 

but commenters saw no need for these.

Table IV-13 FTP Standards for HDVs

NMOG+NOX

(mg/mi)

PM

(mg/mi)

CO

(g/mi)

Formaldehyde

(mg/mi)

Class 2b (8501-10,000 lbs GVWR):

Bin 395 (interim) 395 8 6.4 6

Bin 340 (interim) 340 8 6.4 6

Bin 250 250 8 6.4 6

Bin 200 200 8 4.2 6

Bin 170 170 8 4.2 6

Bin 150 150 8 3.2 6

Bin 0 0 0 0 0

Class 3 (10,001-14,000 lbs GVWR):

Bin 630 (interim) 630 10 7.3 6

Bin 570 (interim) 570 10 7.3 6

Bin 400 400 10 7.3 6

Bin 270 270 10 4.2 6

Bin 230 230 10 4.2 6

Bin 200 200 10 3.7 6

Bin 0 0 0 0 0

The NMOG+NOX standards levels for the highest bins in each class (Class 2b Bin 

395 and Class 3 Bin 630) are equal to the sum of the current non-methane hydrocarbon 

(NMHC) and NOX standards levels that took full effect in 2009, as well as to equivalent 

LEV standards in California’s LEV II program. These bins are intended as carryover 

bins. That is, we expect them to be populated with vehicles that are designed to meet the 

current standards, and that are being phased out as new lower-emitting vehicle designs 

phase in to satisfy the Tier 3 fleet average NMOG+NOX standard. We also consider the 

next highest bins (Class 2b Bin 340 and Class 3 Bin 570) to be carryover bins, because 

they likewise can be readily achieved by vehicles designed for today’s EPA and 

California LEV II emissions programs. As the 2018-2022 phase-in progresses, it will 

become increasingly difficult to produce vehicles in these bins and still meet the fleet 

average standard. Therefore vehicles in these bins (as well as some others not yet 

designed to meet Tier 3 PM standards described in Section IV.B.2.d) will be considered 

“interim Tier 3” vehicles, and the bins themselves will be considered “interim bins.”

To facilitate their use in this carryover function, the interim bins do not require 

manufacturers to meet Tier 3 exhaust emissions standards on the SFTP, over the longer 

useful life, or with the new gasoline test fuel discussed in Section IV.F, although testing 

on this fuel will be allowed. These requirements do apply in all other bins.
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In the context of these relaxed requirements for the interim bins, we proposed two 

additional measures to help ensure these bins are focused on their function of helping 

manufacturers transition to the long-term Tier 3 emissions levels. First, we proposed that 

the interim bins would be available only in the phase-in years of the program; that is, 

through model year (MY) 2021, as is appropriate to their interim status. Second, vehicles 

in the interim bins would meet separate NMOG and NOX standards rather than combined 

NMOG+NOX standards. The goal was to ensure that a manufacturer does not redesign or 

recalibrate a vehicle model under combined NMOG+NOX Tier 3 standards for such 

purposes as reducing fuel consumption, through means that result in higher NOX or 

NMOG emissions than exhibited by today’s vehicles, contrary to the intended carryover 

function of the interim bins. Industry commenters objected to both the proposed 

sunsetting of the interim bins and the proposed separate NOx and NMOG standards, 

arguing that they overly restrict manufacturer flexibility and work against harmonization 

with LEV III. However, commenters did not address EPA’s concern regarding increased 

NOx emissions at the interim bin levels.

After considering the comments, we believe a modified approach to the interim 

bins can at least partly address the industry concerns regarding harmonization while still 

precluding backsliding on NOx levels. We are finalizing the interim bins with combined 

NMOG+NOx standards as requested by the commenters, but are adopting a restriction on 

deterioration-adjusted NOx levels in certification testing, to the levels allowed under the 

current standards in 40 CFR 86.1816-08. These are 0.2 and 0.4 g/mi for Class 2b and 

Class 3, respectively. This restriction will not apply to vehicles in use, and does not 

impose a parallel NMOG restriction. Given our continuing concerns about NOx 

increases that would be allowed by the combined standards at the interim bin levels, we 

believe that this approach and the associated certification burden are reasonable, noting 

that manufacturers already must obtain NOx test results in certifying to an NMOG+NOx 

standard, and the differing NOx and NMOG deterioration mechanisms will likely dictate 

that they be considered separately in obtaining deteriorated NMOG+NOx levels for 

certification.

We believe that making the interim bins available indefinitely would run counter 

to their limited purpose as an aid to making the transition to Tier 3 emissions levels. 

Making these bins permanent would, we believe, necessitate that they take on other key

elements of the Tier 3 program such as longer useful life, SFTP compliance, and the use 

of Tier 3 test fuel. These requirements in turn would negate the usefulness of these bins 

in helping to carry over some pre-Tier 3 vehicle designs during the transition years in 

which the declining fleet average standard levels are high enough to accommodate their 

continued sale. By MY 2022, the fleetwide standard will be stringent enough to 

effectively eliminate the ability of manufacturers to use interim bins while meeting the 

declining fleet average standard levels. We are therefore adopting the sunsetting of the 

interim bins as proposed, making them available only through MY 2021.
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b. Fleet Average NMOG+NOX Standards

As in the light-duty Tier 3 program, a key element of the program we are 

finalizing for HDVs is a fleet average NMOG+NOX standard that becomes more 

stringent in successive model years: in the case of HDVs, from 2018 to 2022. Each HDV 

sold by a manufacturer in each model year contributes to this fleet average based on the 

mg/mi NMOG+NOX level of the bin declared for it by the manufacturer. Manufacturers 

may also earn or use credits for fleet average NMOG+NOX levels below or above the 

standard in any model year, as described in Section IV.B.4. As proposed, we are 

adopting the separate Class 2b and Class 3 fleet average standards shown in Table IV-14, 

though a manufacturer can effectively average the two fleet classes using credits (see 

Section IV.B.4). We believe this split-curve approach is superior to a single phase-in 

covering all HDVs because it recognizes the different Class 2b/Class 3 fleet mixes among 

manufacturers and the differing challenge in meeting mg/mi standards for Class 3 

vehicles compared to Class 2b vehicles, while still allowing for a corporate compliance 

strategy based on a combined HDV fleet through the use of credits.

We are adopting the proposed fleet average NMOG+NOx standards. These are 

consistent with those set for the LEV III MDV program in model years 2018 and later. 

As proposed, we are also adopting provisions allowing manufacturers to voluntarily meet 

bin and fleet average standards in model years 2016 and 2017 that are consistent with the 

MDV LEV III standards in those years, for the purpose of generating credits that can be 

used later or traded to others. These voluntary standards are shown in Table IV-14. This 

voluntary opt-in program serves the important purpose of furthering consistency between 

the federal and California programs, such that manufacturers who wish to can produce a 

single vehicle fleet for sale nationwide, with the opportunity for reciprocal certification in 

affected model years. It further incentivizes pulling ahead of Tier 3 technologies, with 

resulting environmental benefits, by providing for early compliance credits in this 

nationwide fleet. Commenters expressed support for this harmonized array of HDV 

emissions standards.

Manufacturers choosing to opt into this early compliance program could start in 

either model year 2016 or 2017. They would have to meet the full complement of 

applicable bin standards and requirements for the bins they choose for their vehicles in 

meeting the 2016/2017 MY fleet average FTP NMOG+NOX standards, including SFTP 

standards in the bins that have SFTP standards. However, they do not need to meet the 

Tier 3 PM FTP and SFTP standards discussed in Sections IV.B.2.d and IV.B.3.a, or the 

evaporative emissions standards discussed in Section IV.C, because these requirements 

phase in on a later schedule. We are not extending the voluntary compliance opportunity

to the 2015 model year, based on manufacturer comments indicating it would be of little 

value.
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Table IV-14 HDV Fleet Average NMOG+NOX Standards (mg/mi)

Voluntary Required Program

Model 

Year 2016 2017 2018 2019 2020 2021 2022 and later

Class 2b 333 310 278 253 228 203 178

Class 3 548 508 451 400 349 298 247

 

We believe that the voluntary program provisions will benefit the environment, 

the regulated industry, and vehicle purchasers, because it has potential to accomplish 

early emissions reductions while maintaining the goal of a cost-effective, nationwide 

vehicle program in every model year going forward.

Although manufacturers will be allowed to meet the fleet average NMOG+NOX

standard through whatever combination of bin-specific vehicles they choose, it is 

instructive to note that the fully phased in fleet average standard for model years 2022 

and later will be the equivalent of a Class 2b fleet mix of 90 percent Bin 170 and 10 

percent Bin 250 vehicles, and a Class 3 fleet mix of 90 percent Bin 230 and 10 percent 

Bin 400 vehicles. Therefore, it is appropriate to consider Bin 170 Class 2b vehicles and 

Bin 230 Class 3 vehicles to be representative of Tier 3-compliant HDVs in the long term.

c. Alternative NMOG+NOX Phase-in

We believe the fleet average phase-in described above will be flexible, effective, 

and highly compatible with manufacturers’ desire to market vehicles nationwide, because 

of its close alignment with California’s LEV III program for medium-duty vehicles. 

However, for any HDV manufacturers seeking four years of lead time and three years of 

stability as specified in Clean Air Act section 202(a)(3)(C), we proposed an alternative 

compliance path.340 This alternative approach was crafted to be equivalent to the 

NMOG+NOX declining fleet average in the above-described LEV III-harmonized 

alternative in every model year, except that the period for the voluntary program in the 

alternative approach would extend an extra model year—through 2018. To ensure that 

this approach meets the Act’s stability requirement, instead of being structured around an 

annually declining fleet average standard, the alternative approach requires a 

 

340 For vehicles above 6,000 lbs GVWR, Clean Air Act section 202(a)(3)(C) requires EPA to provide 

manufacturers with a minimum of 4 years of lead time before mandatory changes to any standard 

applicable to hydrocarbon, NOX, carbon monoxide, or PM can be implemented, and 3 years of stability 

between changes to any such standard.
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manufacturer to demonstrate compliance (including through use of credits) with a 

schedule of annually increasing percent-of-sales of HDVs certified to the fully phased in 

178 mg/mi (Class 2b) and 247 mg/mi (Class 3) standards, as shown in Table IV-15. We 

are adopting the alternative percent-of-sales phase-in largely as proposed, with limited 

changes described below.

Table IV-15 Percent-of-Sales Alternative NMOG+NOX Phase-in

Voluntary Required Program

Model 

Year 2016 2017 2018 2019 a

2020 2021 2022 and later

Class 2b 29% 39% 54% 65% 77% 88% 100%

Class 3 21% 32% 47% 60% 73% 87% 100%

a Special provisions apply to models with an early-starting 2019 model year.

The availability of emissions averaging under our alternative phase-in, discussed 

below, makes the two alternatives functionally equivalent, not just in the annual 

emissions reductions they achieve, but also in how manufacturers may design their mix 

of products to meet the phase-in standards. Commenters who disagreed with this 

assessment for HDVs did not provide their reasoning, beyond referring to similar 

comments they had on the parallel light-duty (above 6000 lbs GVWR) alternative phasein. However, that proposed alternative differs from the one we proposed for HDVs, and 

the elements in it that were found objectionable by the manufacturers are not in the HDV 

alternative. (See Section IV.A.3 for discussion of comments on the light-duty

alternative.) 

Commenters objected that the proposed percent-of-sales alternative has not been 

shown by EPA to be feasible, or in fact is infeasible because it mandates the early phasein of low-emitting vehicles certified to the final standards. Such comments miss the fact 

that, with ABT, every manufacturer can produce the same mix of vehicles in any model 

year to comply with either HDV phase-in alternative, with the exception that MY 2018 is 

a voluntary phase-in year under the alternative phase-in and a required year under the 

LEV III-harmonized phase-in. The ABT provisions enable a manufacturer to adopt a 

fleet average compliance strategy while utilizing the percent-of-sales phase-in that is 

identical to what would be required under the LEV III-harmonized phase-in’s fleet 

average standards. By no means are manufacturers forced to make only vehicles certified 

to the final standards. The percent-of-sales phase-in is thereby no more stringent than the 

LEV III-harmonized phase-in, and the feasibility analysis provided in Section IV.B.5, 

which expressly addresses the LEV III-harmonized phase-in, serves to demonstrate the 

feasibility of both alternatives. 
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Some comments seem to assert that the percent-of-sales framework for the 

alternative was chosen by EPA to make this alternative so stringent (by requiring some 

vehicles to meet final standards four years early) that no reasonable company would use 

it. This is incorrect, both in regard to its actual effect (which as explained above is not 

more stringent), and in regard to our intent. The percent-of-sales framework for the 

alternative was proposed and is being adopted for the purpose of providing manufacturers 

with a phase-in alternative that explicitly meets the applicable Clean Air Act stability

requirement.

We are making one change to the percent-of-sales alternative, necessitated by the 

fact that this final rule is being signed in 2014, not 2013 as envisioned in the proposal. 

HDV models for which the 2019 model year begins before the fourth anniversary of the 

signature date of this final rule may be excluded from the Tier 3 fleet average compliance 

calculations and all other Tier 3 requirements. These excluded vehicles would instead 

need to comply with the applicable pre-Tier 3 standards and requirements for the entire 

production of these models throughout the 2019 MY. This limited allowance ensures that 

the alternative meets EPA’s obligation for four years of lead time under the Clean Air 

Act. It is similar to a phase-in alternative we provided in the light-duty vehicle Tier 2 

rule (see 65 FR 6747, February 10, 2000). Note that 40 CFR 86.1803-01 defines “model 

year” as “the manufacturer’s annual production period (as determined by the 

Administrator) which includes January 1 of such calendar year: Provided that if the 

manufacturer has no annual production period, the term ‘model year’ shall mean the 

calendar year.” Additional regulations pertaining to the definition of a model year are in 

40 CFR 85, subpart X.

This allowance remains optional within the percent-of-sales alternative-- a 

manufacturer may voluntarily include these early-starting 2019 MY vehicles in the Tier 3 

program, and in this case these vehicles would be treated no differently under the 

alternative than vehicles with a later-starting 2019 MY, including with regard to whether 

manufacturers choose to make them part of the “phase-in” fleet (vehicles counting 

toward the phase-in percentages) or the “phase-out” fleet (vehicles not counting toward 

the phase-in percentages).

Although it is conceivable that manufacturers would commence an early start of 

the 2019 model year specifically for the purpose of delaying Tier 3 obligations, we do not 

think this is likely, given the many important constraints and decisions that typically

factor into setting this date, and the fact that signature of this final rule is occurring 

relatively early in the calendar year, well before typical model year start dates. We 

believe this is a reasonable way to provide a viable percent-of-sales phase-in alternative 

that has four years of lead time without making the 2019 model year voluntary for all 

vehicles or putting new constraints on the timing of a manufacturer’s model year.

To help ensure that the percent-of-sales alternative is fully equivalent to the LEV 

III-harmonized alternative in terms of fleet-wide emissions control and technology mix 

choices, we are including some additional provisions, as proposed. First, the Tier 3 
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vehicles being phased in under the percent-of-sales alternative, in addition to meeting the 

fully phased-in FTP NMOG+NOX standards, must also meet all other FTP and (as 

described below) SFTP standards required by the LEV III-harmonized alternative. These 

include the CO and formaldehyde FTP standards, the 150,000 mile (15 year) useful life 

requirement, exhaust emissions testing with the new test fuel for gasoline- and ethanolfueled vehicles discussed in Section IV.F, and the NMOG+NOX and CO SFTP standards 

in Table IV-16. The specific standards are those for the bins in these tables closest to the 

fully phased-in NMOG+NOX standards: Bin 170 for Class 2b and Bin 230 for Class 3. 

(The PM and evaporative emissions standards phase in on separate schedules under both 

alternatives, as discussed in Sections IV.B.2.d and IV.C.)

Second, we are making an ABT program available for the percent-of-sales 

alternative, structured like the one created for the LEV III-harmonized alternative. This 

involves certifying the vehicles in a manufacturer’s HDV fleet to the bin standards, and 

demonstrating compliance with the fleet average standards for the LEV III-harmonized 

alternative in each model year, including through the use of ABT credits as in the LEV 

III-harmonized alternative. We are using the fleet average calculation method for 

purposes of ABT because, as explained above, we have determined that making this 

demonstration is equivalent to demonstrating compliance with the percent-of-sales 

requirement, and we see no value in complicating the program with another set of 

calculations.

However, we are establishing one difference between the LEV III-harmonized 

and percent-of-sales alternatives with respect to ABT provisions. Unlike in the LEV IIIharmonized alternative, manufacturers will not have to certify all vehicles into bins in 

order to take advantage of the ABT provisions under the percent-of-sales alternative. 

Rather they could choose to certify any “phase-out” vehicles (that is, those not counting 

toward the percent-of-sales phase-in) to the pre-Tier 3 NMHC and NOX standards, 

provided these vehicles do not have family emission limits (FELs) above those standards. 

These non-Tier 3 vehicles will not be subject to the Tier 3 standards or other vehiclespecific elements of the Tier 3 compliance program. There were no comments on these 

specific compliance and ABT provisions associated with the percent-of-sales alternative.

d. Phase-in of PM Standards

Consistent with the light-duty Tier 3 program discussed in Section IV.A, we are 

phasing in the PM standards for HDVs as an increasing percentage of a manufacturer’s 

production of chassis-certified HDVs (combined Class 2b and 3) per year. In addition to 

concerns regarding the availability and required upgrades of test facilities used for both 

light-duty and heavy-duty vehicle testing, manufacturers have expressed uncertainty 

about PM emissions with new engine and emissions control technologies entering the 

market as a result of new greenhouse gas (GHG) standards. Therefore we are adopting 

the same phase-in schedule as for the light-duty sector in model years 2018-2019-2020-

2021: 20-40-70-100 percent, respectively. This will apply to HDVs certified under 

either NMOG+NOX phase-in alternative. The California Air Resources Board (CARB) is 
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phasing in the LEV III PM standards for HDVs on the same schedule, except that LEV 

III will also involve a 10 percent PM phase-in in the 2017 model year. We asked for 

comment on our adding this to our voluntary program for 2017, but received no 

comments on it and are not including it in the Tier 3 program.

For manufacturers choosing the declining fleet average NMOG+NOX compliance 

path, the PM phase-in requirement for HDVs will be completely independent of the 

NMOG+NOX phase-in, with no requirement that both phase-ins be met on the same 

vehicles. As a result, vehicles certified to any of the bin standards for NMOG+NOX need 

not necessarily meet Tier 3 PM standards before the 2021 model year. Instead, the 

current 0.02 g/mi PM standard will apply for those vehicles not yet phased into the Tier 3 

PM standards. We are requiring that manufacturers choosing the percent-of-sales phasein alternative for NMOG+NOX meet the PM phase-in requirements with only those 

vehicles certified to the Tier 3 NMOG+NOX standard, except in the 2019 and earlier

model years when the standards, including the PM standards, are voluntary, and in the 

2021 model year when the 100 percent PM phase-in requirement exceeds the 87-88 

percent NMOG+NOX phase-in requirement. This is appropriate given the ability of 

manufacturers to build “phase-out” vehicles (those not counting toward the phase-in 

percentages) under the percent-of-sales NMOG+NOx alternative that are certified 

entirely to pre-Tier 3 standards while still participating in the Tier 3 ABT program, 

discussed above.

We will consider any vehicle under either compliance path that is not certified to 

Tier 3 standards for PM and NMOG+NOX (as well as the other, concomitant Tier 3 

standards and requirements such as the extended useful life), an “interim Tier 3” vehicle. 

This term also applies to vehicles certified in one of the interim bins, as discussed above.

Note that compliance with Tier 3 evaporative emissions requirements follows a 

separate phase-in schedule as described in Section IV.C. As a result, a vehicle in an 

exhaust emissions family that the manufacturer has phased in to the new useful life and 

test fuel requirements may be in an evaporative emissions family that has not yet phased 

in the Tier 3 useful life and test fuel for evaporative emissions compliance and testing.

i. Optional PM Phase-in

The percent-of-sales phase-in schedule for the PM standard, described above, will 

allow manufacturers with multiple vehicle models to determine and plan the phase-in of 

those models based on anticipated sales volumes of each model. However, 

manufacturers certifying only a few vehicle models may not be able to take meaningful 

advantage of this schedule. This is because their limited number of models may force 

them to over-comply to reach the required minimum percentages, compared to a 

manufacturer with many vehicle models available from which to choose a phase-in 

pathway.
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For instance, a manufacturer with only two models that each equally account for 

50 percent of its sales would be required to introduce (at least) one of the models in MY 

2018 to meet the phase-in requirement of 20 percent in the first year. At the 50 percent 

level, this model would then also meet the requirements for MY 2019 (40 percent). To 

meet the MY 2020 requirement of 70 percent of sales, however, the manufacturer would 

need to introduce the second Tier 3 vehicle that year. Thus the manufacturer would have 

introduced 100 percent of its Tier 3 models one year earlier compared to a manufacturer 

that was able to delay the final 30 percent of its fleet until MY 2021 by distributing its 

redesign of models over the entire phase-in period.

To provide for more equal application of this benefit among all manufacturers in 

the early years of the program, we are adopting the proposed optional “indexed” phase-in 

schedule that could be used by a manufacturer to meet the phase-in requirements. A 

manufacturer that exceeds the phase-in requirements in any given year will be allowed to, 

in effect, offset some of the phase-in requirements in a later model year. The optional 

phase-in schedule will be acceptable if it passes a mathematical test. The mathematical 

test is designed to provide manufacturers a benefit from certifying to the standards at 

higher volumes than they are obligated to under the normal phase-in schedule, while 

ensuring that the overall population of complying vehicles at the end of the phase-in is 

roughly the same as under the fixed percentage approach. In this alternative approach, 

manufacturers will weight Tier 3 PM-compliant vehicles in the earlier years by 

multiplying their percent phase-in by the number of years prior to MY 2022 (that is, the 

second year of the 100 percent phase-in requirement). 

The mathematical equation for applying the optional phase-in is as follows:

(4 x APP2018) + (3 x APP2019) + (2 x APP2020) + (1 x APP2021) ≥ 440, 

where APP is the actual phase-in percentage for the referenced model year. The sum of 

the calculation will need to be greater than or equal to 440, which is the result when the 

optional phase-in equation is applied to the primary percent phase-in schedule (4 x 20% + 

3 x 40% + 2 x 70% + 1 x 100% = 440). Commenters supported this optional PM phasein approach.

3. Supplemental FTP Standards for HDVs

Unlike passenger cars and light trucks, HDVs are not currently subject to SFTP 

standards. SFTP standards are intended to ensure vehicles have robust emissions control 

over a wide range of real-world driving patterns not well-covered by the FTP drive cycle. 

Even though HDVs are not typically driven in the same way as passenger cars and LDTs, 

especially as they frequently carry or tow heavy loads, we believe some substantial 

portion of real world heavy-duty pickup and van driving is not well-represented on the 

FTP cycle.
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The goal in setting the SFTP standards levels is not to force manufacturers to add 

expensive new control hardware for off-FTP cycle conditions, but rather to ensure a 

robust overall control program that precludes high off-FTP cycle emissions by having 

vehicle designers consider them in their choice of compliance strategies. High off-FTP 

cycle emissions, even if encountered relatively infrequently in real-world driving, could 

create a substantial inadequacy in the Tier 3 program, which aims to achieve very low 

overall emissions in use. The SFTP provisions will also help make the HDV program 

more consistent with the heavy-duty engine program, which for several years has 

included “not-to-exceed” provisions to control off-cycle emissions. Therefore, in addition 

to the SFTP provisions, we are further limiting enrichment on spark ignition engines in 

all areas of operation unless absolutely necessary.

a. SFTP NMOG+NOX, PM and CO Standards

The SFTP standards levels are provided in Table IV-16. These are consistent 

with those adopted in the LEV III program.

Table IV-16 SFTP Standards for HDVs

Vehicles in 

FTP Bins:

NMOG+NOX

(mg/mi)

PM

(mg/mi)

CO

(g/mi)

Class 2b with hp/GVWR ≤ 0.024 hp/lb:a

FTP Bins 200, 250 550 7 22.0

FTP Bins 150, 170 350 7 12.0

Class 2b:

FTP Bins 200, 250 800 10 22.0

FTP Bins 150, 170 450 10 12.0

Class 3:

FTP Bins 270, 400 550 7 6.0

FTP Bins 200, 230 350 7 4.0

a These standards apply for vehicles optionally tested using emissions from only the highway portion of the 

US06 cycle. 

We are linking Tier 3 SFTP implementation for HDVs directly to the Tier 3 FTP 

phase-in and bins for these vehicles. That is, an HDV certified to any of the Tier 3 FTP

bin standards must meet the SFTP standards for that bin as well. However, because the 

FTP PM standard phases in on a separate schedule, we will require that SFTP PM 

compliance be linked to the same schedule. That is, an HDV certified to the Tier 3 FTP 

PM standard must meet the applicable SFTP PM standard as well. This approach 

recognizes the complementary nature of FTP and SFTP provisions and helps to ensure 

that Tier 3 emissions controls are robust in real world driving. CARB expressed support 

in its written comments for this approach to linking FTP and SFTP requirements and an 

intent to propose aligning LEV III with it once the Tier 3 program is finalized.
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There are no SFTP requirements for the interim Tier 3 bins in each class (Class 2b 

Bins 340 and 395 and Class 3 Bins 570 and 630), because these are essentially carry-over 

bins from the previous standards to help facilitate the transition to Tier 3, and therefore 

are not intended to take on new requirements that might prompt a redesign. These 

implementation provisions are consistent with the approach taken in the LEV III 

program, except that California applies more of the Tier 3 requirements for SFTP and 

extended useful life to vehicles in the interim bins.

To help ensure a robust SFTP program that achieves good control over a wide 

range of real world conditions, we proposed to use a weighted-average composite SFTP 

cycle, with NMOG+NOX emissions calculated from results of testing over three cycles: 

the US06, the FTP, and the SC03, weighting these results by 0.28, 0.35, and 0.37, 

respectively. However, at proposal, we determined that the full US06 component of the 

composite cycle, along with the ALVW loaded test condition, would not be sufficiently

representative of real-world driving for two groups of HDVs: those with low power-toweight ratios and Class 3 vehicles.

Therefore, as discussed in the proposal, SFTP testing of Class 2b vehicles with 

power-to-weight ratios at or below 0.024 hp/lb, may, at the manufacturer’s option replace 

the full US06 component of the composite SFTP emissions with the test results from only

the second of the three emissions sampling bags in the US06 test, generally referred to as 

the “highway” portion of the US06. HDVs so tested will be subject to the 

correspondingly lower SFTP standards levels shown in the table above. These vehicles 

will be driven during the test in the same way as the higher power-to-weight Class 2b 

vehicles (over the full US06 cycle), using best effort (maximum power) if the vehicle 

cannot maintain the driving schedule. The large majority of Class 2b vehicles-- those 

with power-to-weight above 0.024 hp/lb --will be required to include emissions over the 

full US06 cycle in the composite SFTP. We believe that this approach provides a robust 

but repeatable and reliable test for the full range of Class 2b vehicles, as the highway

portion of the US06 retains broad coverage of vehicle speed/acceleration combinations 

measured in real-world driving. Any testing conducted by EPA would follow the 

manufacturer’s test path for the vehicle.

For Class 3 vehicles, which range up to 14,000 lbs GVWR, we are also concerned 

that the full US06 cycle would not provide a representative drive cycle for SFTP testing. 

These vehicles are much larger than the light-duty vehicles that formed the basis for 

development of the US06 cycle, and loading them to ALVW for the SFTP test yields a 

very heavy test vehicle, not likely to be safely driven in the real world in a manner that is 

typified by this aggressive cycle. We believe that the LA-92 (or “Unified”) driving cycle 

developed by CARB is more representative of Class 3 truck driving patterns and will 

produce more robust results for use in SFTP evaluations. Therefore we are adopting the 

proposed LA-92 cycle for use in place of the US06 component of the composite SFTP for 

Class 3 HDVs. 
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HDVs do not have SC03 emissions requirements under the current HDV 

standards. Manufacturers of HDVs have indicated that they expect the SC03 emissions 

to be consistently lower than either the US06 or the FTP emissions levels, and therefore 

the added SC03 testing burden may be unnecessary. We are therefore providing HDV 

manufacturers with the option to substitute the FTP emissions levels for the SC03 

emissions results for purposes of compliance. However, we will retain the ability to 

determine the composite emissions using SC03 test results in confirmatory or in-use 

testing. We received no adverse comments on this proposed approach.

The set of composite SFTP cycles and standards we proposed and are adopting 

for HDVs is consistent with the MDV LEV III program. We received no adverse 

comments on them, except with regard to in-use testing as discussed in Section IV.B.6.a.

b. Enrichment Limitation for Spark-Ignition Engines

To prevent emissions from excessive enrichment in areas not fully encountered in 

the SFTP cycles, we proposed and are adopting limitations in the frequency and 

magnitude of enrichment episodes for spark-ignition HDVs. These limitations are 

identical to those for light-duty vehicles. See Section IV.A.4.c for discussion of the 

requirements and relevant comments received.

4. HDV Emissions Averaging, Banking, and Trading

This section describes how exhaust emissions credits may be earned and used. 

See Section V.C for similar provisions that apply for evaporative emissions. We are 

continuing the practice of allowing manufacturers to satisfy standards through the 

averaging of emissions, as well as through the banking of emissions credits for later use 

and the trading of credits with others.

There are a number of facets of the Tier 3 ABT program for HDVs that are 

different from the existing program. First, instead of separate NMHC and NOX credits, 

manufacturers earn combined NMOG+NOX credits, consistent with the form of the 

standards.

Second, manufacturers may accrue a deficit in their credit balance. Deficits 

incurred in a model year may be carried forward but a manufacturer will not be permitted 

to have a negative overall HDV credit balance in more than 3 consecutive model years. 

Manufacturers will have to use any new credits to offset any shortfall before those credits 

can be traded or banked for additional model years. Credits not used within 5 years after 

they are earned will be forfeited. These 5/3-year credit/deficit life provisions are 

consistent with our light-duty Tier 3 approach, the California LEV III program for 

MDVs, and EPA programs for controlling GHG emissions from light- and heavy-duty 

vehicles.

Third, as part of our new requirement for chassis certification of complete diesel 

HDVs, we are allowing the chassis-certified diesel HDVs to participate in the Tier 3 ABT 
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program without restriction. Prior to Tier 3 they have not been allowed to earn or use 

ABT credits. We are not restricting or adjusting credit exchange between diesel and 

gasoline-fueled HDVs, consistent with our shift to combined NMOG+NOX standards that 

helps to ensure comparable stringency for these two engine types, and consistent also 

with the LEV III MDV program.

Credits earned by a chassis-certified Tier 3 HDV may be used to demonstrate 

compliance with NMOG+NOX standards for any other chassis-certified Tier 3 HDV, 

regardless of size and without adjustment. This effectively allows manufacturers to plan 

a comprehensive HDV compliance strategy for their entire Class 2b and Class 3 product 

offering, by balancing credits so as to demonstrate compliance with the standards for both 

classes.

Industry commenters argued that EPA should align the HDV credit provisions 

with the light-duty program by allowing early Tier 3 credits to be generated in MYs 2016 

and 2017, calculated relative to the highest Class 2b and Class 3 bin NMOG+NOx levels 

(395 and 630 mg/mi, respectively), and capped at a level proportional to the California 

level in MY 2018. However, these highest bin levels correspond to those of the existing 

HDV standards for NMHC and NOx, and are significantly higher than the MY 2016 and 

2017 LEV III levels. Thus vehicles designed to just meet the LEV III standards in these 

years could generate a large preliminary number of credits under the industry’s Tier 3 

early credits proposal, credits they would not earn in LEV III, thereby potentially

thwarting the harmonization of the two programs. Truncating that credit bank for each 

manufacturer in 2018 such that it is proportional to their LEV III balance could perhaps, 

with additional restrictions on trading and banking, restore a harmonized credit status in 

that year. However, it constitutes an unnecessarily complex and uncertain pathway to the 

same result as that achieved under EPA’s early opt-in provisions.

Commenters requested that we provide for the conversion of pre-Tier 3 HDV 

credits for use in Tier 3. However, as discussed in the proposal, we are not including 

provisions for doing so. We believe that by providing an early Tier 3 opt-in program for 

HDVs, capable of generating credits for two model years before the mandatory standards 

take effect (even longer under the alternative percent-of-sales phase-in approach), we are 

giving ample opportunity for the manufacturers to accumulate early credits.

Manufacturers commented that the proposed fleet average compliance approach is 

incongruous with California’s LEV III method based on vehicle equivalent credits 

(VECs). Although expressing that they have no preference for the method since the 

stringency is equivalent, they recommended that EPA foster harmonization by providing 

a compliance option based on VECs. We believe that such an option would add 

unnecessary complexity to the Tier 3 program, and is made even more unnecessary by

the intent expressed in CARB’s written comments to propose a fleet average option for 

LEV III that is identical to EPA’s approach.
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In the past we have set upper bounds, called family emission limit (FEL) caps, on 

how high emissions can be for credit-using vehicles, regardless of how many credits 

might be available. Under our Tier 3 bin structure, we believe that exhaust emission FEL

caps are no longer relevant for Tier 3 HDVs, as every vehicle must meet whatever 

standards apply in the bin chosen for the vehicle by the manufacturer. (The bin standard 

becomes the effective FEL.) Indeed, because credits and deficits are calculated based on 

the difference between a manufacturer’s fleet average emissions and the fleet average 

standards for a given model year, credits are not calculated for individual vehicle families 

at all. Thus the standard for NMOG+NOX in the highest allowable bin serves the purpose 

of the FEL caps in previous programs.

Consistent with our proposal, we are not creating an averaging program for the 

HDV SFTP program, because we believe that the bin structure and FTP-centered 

NMOG+NOX ABT program provide adequate flexibility for smooth program 

implementation, especially in light of our aim to have the FTP standards be the primary

technology forcers. A separate ABT program for SFTP compliance would add 

substantial complexity with little benefit, and, by making it possible to demonstrate 

robust SFTP emissions control on a vehicle that lacks commensurate FTP control, could 

prove at odds with the primary goal of the supplemental test for HDVs.

5. Feasibility of HDV Standards

The feasibility assessment, discussed in more detail in Chapter 1 of the RIA, 

recognizes that the Tier 3 program is composed of several new requirements for Class 2b 

and 3 heavy-duty vehicles, which include primarily large gasoline and diesel pick-up 

trucks and vans with diverse application-specific designs. These new exhaust emissions 

requirements include stringent NMOG+NOX and PM standards for the FTP and the 

SFTP, that will as a whole require new emissions control strategies and hardware in order 

to achieve the standards. The type of new hardware that will be required will vary

depending on the specific application and emissions challenges. Additionally, gasoline 

and diesel vehicles will require different emissions control strategies and hardware. The 

level of stringency for the SFTP NMOG+NOX standards will generally only require 

additional precise control of the engine parameters not necessitated in the past because of 

the lack of SFTP requirements. Similarly, the new PM standards on both the FTP and 

SFTP cycles will require more precise control of engine operation on gasoline vehicles 

while diesels already equipped with diesel particulate filters will require minimal

changes. The new PM standards may also require that manufacturers consider the 

durability of their engines to the 150,000 miles useful life requirement with respect to 

engine wear resulting in increased oil consumption and potentially higher PM emissions.

In order to assess the technical feasibility of NMOG+NOX national fleet average 

FTP standards of 178 mg/mi for Class 2b vehicles and 247 mg/mi for Class 3 vehicles, 

we conducted an analysis of certification data for the HDVs certified in the 2010 and 

2011 MYs. For this final rule, we also reviewed certification records for 2012 and 2013 

MY vehicles, and determined that these primarily involve carryover engines and emission 
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control hardware. Therefore we did not update the NPRM analysis however any new or 

updated certification results in the 2012 or 2013 MYs are included in the RIA chapter 1 

discussion. This analysis provided a baseline for the current HDV fleet emissions 

performance, as well as the emissions performance specific to the Class 2b and 3 

vehicles. The emissions performance of each heavy-duty vehicle class specific to 

gasoline and diesel is shown in Table IV-17 below. It is important to note that the 

emissions results are only the 4000 mile test point results and do not incorporate any 

deterioration which manufacturers must account for when certifying to a full useful life 

standard. Designs limiting the deterioration of emission control hardware are critical to 

meeting the emission standards at the useful life of the Tier 3 program. Deterioration 

factors to adjust the values to the Tier 3 useful life standard of 150,000 miles were not 

available. However, deterioration factors to adjust to 120,000 miles useful life, and their 

implications for performance at higher miles, are discussed in the RIA Chapter 1. 

The analysis also reflects the importance of the combined NMOG+NOX standard 

approach, where diesels and gasoline HDVs can balance their combined NMOG and 

NOX levels. Diesel vehicles in the analysis produce very low NMHC emissions (NMOG 

is not reported for diesels) but higher NOX emissions, while gasoline vehicles have 

opposite performance. The combined standard allows manufacturers to determine the 

proper balance of the unique emissions challenges of a diesel or gasoline vehicle.

Table IV-17 2010/11 Certification Test Results at 4000 Miles

NMHC NMOG NOX CO NMOG+NOX

Gasoline Class 2b 0.050 0.052 0.041 1.648 0.092

Class 3 0.080 0.083 0.073 2.373 0.156

NMHC+NOX

Diesel Class 2b 0.037 0.138 0.195 0.174

Class 3 0.019 0.249 0.158 0.268

Combined Class 2b 0.043 0.026 0.089 0.922 0.133

Combined Class 3 0.050 0.041 0.161 1.265 0.212

Manufacturers typically certify their vehicles at emissions levels well below the 

numerical standards. This difference is referred to as “compliance margin” and is a result 

of manufacturers’ efforts to address all the sources of variability that could occur during 

the certification or in-use testing processes and during in-use operation. These sources of 

variability include: test-to-test variability, test location, build variation and 

manufacturing tolerances, vehicle operation (for example: driving habits, ambient 

temperature, etc.), and the deleterious effects of sulfur and other oil and fuel 

contaminants. To meet the NMOG+NOX standard of 178 mg/mi for Class 2b and 247 

mg/mi for Class 3 vehicles and establish a compliance margin for these sources of 
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variability, manufacturers will need to reduce their emission levels considerably from the 

levels indicated in this data set, particularly for diesel vehicles.

However, as discussed above, these emission results do not include the expected 

emissions deterioration which will be determined by manufacturers during development 

and certification testing. Therefore, manufacturers will need to further reduce emissions 

levels in anticipation of the unavoidable emissions deterioration that will occur during the 

useful life of the vehicle. Further, deterioration is a function of several factors, but it is 

predominantly due to emissions control hardware thermal exposure (high temperatures), 

which is typically a significant issue on vehicles used for performing work like Class 2b 

and 3 vehicles. 

We also expect that the 2011 heavy-duty GHG rule will present new challenges to 

manufacturers’ emissions performance goals as vehicles begin to use new engines 

designed to meet the new GHG requirements.341 Some of these new technologies may

result in emissions challenges that are specific to certain operating conditions. For 

example, downsized gasoline engines will likely have improved FTP exhaust emissions 

but have increased challenge with the high-load SFTP requirements. Diesel-fueled 

vehicles may need to carefully balance engine controls which reduce GHG emissions but 

can increase criteria emissions (NOX).

With regard to the ability of the heavy-duty fleet to meet the PM standards for the 

FTP and the SFTP, we based our conclusions on some testing of current heavy-duty

gasoline vehicles (HDGVs) and the PM performance of the existing light–duty fleet with 

similar engines. Testing of two HDGVs with the highest sales volume (Ford F250 and 

Chevrolet Silverado 2500), albeit not aged to full useful life, confirmed that they have 

similar PM emissions levels as the light-duty counterparts and therefore also meet the 

standards for both the Class 2b and Class 3 configurations. Data from light-duty gasoline 

vehicles with similar or common engines with their heavy-duty “sister” vehicle models 

demonstrates that these vehicles are currently meeting the Tier 3 FTP PM standards at the 

Tier 2 useful life mileage of 120,000 miles. Heavy-duty diesel vehicles all are equipped 

with DPFs and have no challenges meeting the FTP or SFTP PM standards being set for 

Tier 3. 

The SFTP test data from the same two heavy-duty vehicles described above 

indicates that gasoline vehicles can achieve the standards for SFTP NMOG+NOX and 

PM. Since heavy-duty vehicles are not currently required to comply with any of the 

SFTP requirements, manufacturers have not focused on improving the emissions 

performance specifically over the SFTP cycles (US06, LA-92, and SC03). Therefore, 

although the limited testing results had a high degree of variability, several tests met the 

PM standards for the high power-to-weight Class 2b vehicles. Consistent with light-duty, 

 

341 76 FR 57106 (September 15, 2011).
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vehicles that are demonstrating high PM on the US06 will need to control enrichment and 

oil consumption from engine wear. Recently manufacturers have already been 

implementing product changes to reduce oil consumption to address both customer 

satisfaction issues and to reduce cost of vehicle ownership.

Given the technologies likely to be applied to meet the HDV exhaust emissions 

standards, discussed below, we consider the lead time available before the standards take 

effect under all of the alternatives to be sufficient. HDV manufacturers are already

adopting some of the complying technologies, especially for their light-duty vehicles, and 

these can readily be adapted for heavy-duty applications. In addition, manufacturers have 

already begun developing these technologies for HDVs, including diesels, in response to 

California’s recently adopted LEV III MDV standards which begin to take effect in the 

2015 model year. Finally, as described above in Sections IV.B.2, IV.B.3, and IV.B.4, our 

program incorporates a number of phase-in and alternative compliance provisions that 

will ease the transition to final standards without disrupting heavy-duty pickup and van 

product redesign cycles. Among these is an alternative phase-in that does not begin 

mandatory standards until model year 2019.

Comments we received on the proposed HDV standards did not specifically 

address our analysis of their technical feasibility. The Manufacturers of Emission 

Controls Association (MECA) outlined diesel and gasoline-engine technologies that they

expect will be used to achieve the Tier 3 standards cost-effectively, generally consistent 

with our draft RIA. Vehicle and engine industry commenters argued that the case we 

made for feasibility relied too heavily on extending light-duty truck test data, 

supplemented by testing of only two HDVs, neither of which were fully aged or 

representative of future vehicles designed to meet our new GHG standards. However, 

commenters did not question the feasibility, durability, implementability, or effectiveness 

of the technologies we identified, or their ability to achieve the proposed standards. 

Instead, the focus of these comments was on statutory provisions for lead time and 

stability, and on how relaxed standards for in-use testing and testing at high altitudes 

would help to implement the standards within the allotted lead time. These issues, 

including changes we are making in response to the comments, are addressed in Sections 

IV.B.2.c, IV.B.6.a, and IV.B.6.f.

i. Technologies Likely to be Applied

The technologies expected to be applied to vehicles to meet the lower standards 

levels will address the emissions control system’s ability to control emissions during cold 

start. Current vehicle emissions control systems depend on the time it takes for the 

catalyst to light-off, which is typically defined as the catalyst reaching a temperature of 

250 °C. While the specific emissions challenge is somewhat different for gasoline 

engines than for diesel engines, achieving the necessary temperatures in the catalysts is a 

common challenge. In order to improve catalyst light-off, the manufacturers will likely

add technologies that provide heat from combustion more readily to the catalyst or 

improve the catalyst efficiency at lower temperatures. These technologies could include 
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calibration changes, thermal management, close-coupled catalysts, catalyst Platinum 

Group Metal (PGM) loading, and possibly secondary air injection. In some cases, where 

the catalyst light-off response and efficiency are not enough to address the cold start 

emissions, hydrocarbon adsorbers may be applied to trap hydrocarbons until such time 

that the catalyst is lit-off. Note that with the exception of hydrocarbon adsorbers each of 

these technologies addresses both NMOG and NOX performance. Key potential 

technologies are described in greater detail below.

 Engine Control Calibration Changes – These include changes to retard spark 

and/or adjust air/fuel mixtures such that more combustion heat is created 

during the cold start on gasoline engines. Diesel engines may use unique 

injection timing strategies or other available engine control parameters. 

Engine calibration changes can affect NMOG, NOX and PM emissions.

 Thermal Management – This technology includes all design attributes meant 

to conduct the combustion heat into the catalyst with minimal cooling on both 

gasoline and diesel engines. This includes insulating the exhaust piping 

between the engine and the catalyst, reducing the wetted area of the exhaust 

path and/or reducing the thermal mass of the exhaust system. Close-coupling 

of catalysts (packaging the catalysts as close to the head of the engine as 

possible to mitigate the cooling effects of longer exhaust piping) can also be 

effective, but is more difficult to employ than in light-duty applications 

because of durability concerns with highly loaded operation and the potential 

increase in fuel consumption to protect the catalyst from high temperatures.

 Catalyst PGM Loading – Additional PGM loading in the catalyst provides a 

greater number of sites to catalyze emissions and addresses NMOG, NOX and 

PM emissions.

 Selective Catalytic Reduction Optimization – Diesel applications will 

continue to refine this NOX emissions control strategy through improved 

hardware design and implementation in vehicle applications. Additional 

engineering enhancements in the control of the SCR system and related 

processes will also help reduce emissions levels.

6. Other HDV Provisions

a. In-Use Emissions

The proposal requested comment on the need for relaxation of NMOG+NOx and 

PM standards for in-use vehicle testing. The LEV III program includes these on an 

interim basis in the more stringent bins in both FTP and SFTP testing. However, in its 

written comments, CARB expressed the view that the technologies required for SFTP 

compliance are well-established, and that sufficient lead time is provided such that 

interim in-use standards for SFTP are not needed. As a result, CARB expressed an intent 
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to propose aligning the LEV III program with the approach EPA proposed on this matter 

after the Tier 3 program is finalized. The manufacturers commented that relaxed interim 

in-use standards are needed in the HDV sector, both for FTP and SFTP standards. The 

reasons cited were a need to harmonize with LEV III, the scarcity of data on which to 

establish standards that apply over the full useful life, the extension of that useful life to 

150,000 miles, the need for manufacturers to address customer concerns with new 

products and technologies, uncertainties that accompany the new SFTP cycles and Part 

1066 testing requirements (especially for PM), and the introduction of innovative 

technologies required to meet GHG standards in the same timeframe.

After considering the comments we have concluded that relaxed interim in-use 

standards are appropriate for HDVs, both for FTP and SFTP testing. We are adopting 

HDV in-use standards levels that are identical to those adopted for LEV III, as shown in 

Table IV-18. We consider these levels reasonable, in line with relaxed in-use standards 

adopted in past programs, and helpful toward harmonization. We are not applying 

interim in-use NMOG+NOx standards to the interim (two highest) bins for the FTP 

standards, because these bins are intended for carry-over of existing designs, and there 

should be little uncertainty over their in-use emissions performance. Interim bin vehicles 

certified to the Tier 3 PM standards shall, however, be subject to the relaxed in-use PM 

standards in the same way as for HDVs in other bins. Bin 0 standards are driven by

specific zero-emissions technologies for which in-use margins would not be appropriate, 

and so we are not setting in-use standards for Bin 0.

We are also adopting the general approach taken in LEV III of making these 

interim standards available during the phase-in period (model years 2016-2022) for the 

first two model years that a test group is newly certified to a Tier 3 NMOG+NOx or PM 

standard. Test groups subsequently recertified to a more stringent NMOG+NOx bin 

standard may begin the two year cycle over again. A test group that is first certified into 

a Tier 3 bin in model year 2022 or later may not take advantage of the relaxed interim inuse standards. LEV III adopted somewhat different applicability years, for the most part 

ending earlier, in model year 2020. However, we believe that the modest extension is 

appropriate to facilitate the Tier 3 phase-in. If a vehicle test group is certified into a Tier 

3 bin, but not yet to the Tier 3 PM standard, the in-use standard for PM shall apply for the 

first two model years it is first certified to the PM standard. In order to better harmonize 

with LEV III, the availability of these in-use standards includes the voluntary model 

years.

Table IV-18 Interim In-Use Standards for HDVs

FTP (mg/mi) SFTP (mg/mi)

NMOG+NOX PM NMOG+NOX PM

Class 2b:

Bin 395 (interim) --

a

16 --

a

--

a

Bin 340 (interim) --

a

16 --

a

--

a

Bin 250 370 16 770/1120 b12/15b
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Bin 200 300 16 770/1120 b12/15 b

Bin 170 250 16 490/630 b12/15 b

Bin 150 220 16 490/630 b12/15 b

Bin 0 --

a

--

a

--

a

--

a

Class 3:

Bin 630 (interim) --

a

20 --

a

--

a

Bin 570 (interim) --

a

20 --

a

--

a

Bin 400 600 20 770 12

Bin 270 400 20 770 12

Bin 230 340 20 490 12

Bin 200 300 20 490 12

Bin 0 --

a

--

a

--

a

--

a

a

 No relaxed interim in-use standard. 

b

 The lower value applies to low power-to-weight vehicles optionally certified using only the highway 

portion of the SFTP US06.

b. HDV Useful Life

Currently the HDV regulatory useful life, the period of use or time during which 

emissions standards apply, is 120,000 miles or 11 years, whichever occurs first (40 CFR 

86.1805-4). For Tier 3 vehicle criteria emissions we are extending the useful life to 

150,000 miles or 15 years, whichever occurs first. This change better reflects the 

improvements in vehicle durability and longevity that have occurred in the several years 

since the 120,000 mile useful life was established, and maintains consistency with the 

LEV III MDV program and with our Tier 3 program for large LDTs, for which the same 

useful life period is being adopted.

The new useful life requirement applies to Tier 3 HDVs in all bins except those 

designated as interim bins, consistent with the purpose of the interim bins to provide for 

limited carry-over of pre-Tier 3 vehicle designs during the phase-in period. Although the 

percentage application in each year will therefore depend on each manufacturer’s fleet 

binning strategy, the declining NMOG+NOX fleet average standard will ensure a robust 

phase-in of the new useful life requirement over the 2018-2022 model years, such that it 

is expected to be about 50 percent in 2018, and necessarily reaches 100 percent by 2022 

when the interim bins are no longer available. For those manufacturers choosing to 

certify to the voluntary standards, the new useful life will apply even earlier, in model 

year 2016 or 2017. For manufacturers choosing the alternative percent-of-sales 

NMOG+NOX alternative, the new useful life requirement applies to all HDVs counted 

toward the phase-in requirement, resulting in a generally equivalent useful life phase-in 

rate to that of the LEV III-harmonized alternative. 

See Section IV.F.5 for further discussion of useful life requirements with regard 

to GHG standards. Manufacturers may optionally retain the 120,000 mile/11 year useful 
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life for PM on interim Tier 3 vehicles that are not phased in to the Tier 3 PM standards. 

We received no adverse comments on these useful life provisions.

c. Heavy-Duty Alternative Fuel Vehicles

As in the light-duty program, manufacturers must demonstrate heavy-duty 

flexible fuel vehicle (FFV) and dual-fuel vehicle compliance with both the FTP and the 

SFTP emissions standards when operating on both the conventional petroleum-derived 

fuel and the alternative fuel. Dedicated alternative fuel vehicles must demonstrate 

compliance with both the FTP and SFTP emission standards while operating on the 

alternative fuel. For all of these vehicles, this includes the requirement to meet FTP 

emissions standards when conducting fuel consumption and GHG emissions testing, and 

also to meet the FTP and highway test requirements at high altitudes (see Sections 

IV.B.6.e and f). Because FFVs can operate on various combinations of their 

conventional and alternative fuel, the emissions requirements apply to operation at any 

mix of the fuels achievable in the fuel tank with commercially available fuels, including 

for compliance at high altitudes, even though the required demonstration of compliance is 

limited to the conventional and alternative fuels designated for certification testing. We 

received no adverse comments on these provisions.

d. Existing Provision to Waive HDV PM Testing

EPA’s existing program includes a provision for manufacturers to waive 

measurement of PM emissions in non-diesel heavy-duty vehicle emissions testing. As 

proposed, we are eliminating this provision. We believe that the Tier 3 PM standards for 

these vehicles are of sufficient stringency that routine waiver of testing is not appropriate. 

The CARB LEV III program also reflects this view. We do not expect this change to be 

onerous for manufacturers, as the number of heavy-duty vehicle families is not large. We 

received no adverse comments on this change.

e. Meeting HDV Standards in Fuel Consumption and GHG Emissions Testing

As with the light-duty Tier 3 program, HDVs must meet the FTP bin standards 

when tested over both the city and highway test cycles. We do not believe this adds a 

very significant test burden as vehicle emissions are already required to be measured 

when these tests are run for GHG and fuel consumption determinations. Nor do we 

believe that this requirement is design forcing. Rather, we are creating this requirement 

to ensure that test vehicle calibrations are not set by manufacturers to minimize fuel 

consumption and GHG emissions, at the expense of causing high criteria pollutant 

emissions. Considering the additional work involved in measuring PM emissions and the 

reduced likelihood of high PM emissions on the highway test, we are not mandating that 

PM emissions testing be included in this requirement. We received no adverse comments 

on these proposed provisions.
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f. HDV Altitude Requirements

As in the past, we intend that HDV Tier 3 standards result in emissions controls 

that are effective over a full range of operating altitudes. We proposed that HDVs be 

required to meet the FTP bin standards (but not the SFTP standards) at high altitudes, and 

expressed our expectation that compliance with the FTP standards would require neither 

the use of special hardware nor adjustment to the level of the standards.

The manufacturers argued in their comments that the reasons EPA cited in 

proposing relief at high altitudes for light-duty vehicles apply for HDVs as well, and 

requested that relaxed NMOG+NOx standards be adopted in the more stringent bins for 

testing of HDVs at high altitudes. Ford argued that the challenges could be even greater 

for HDVs because they are designed to operate at high altitudes with heavy payloads and 

towed trailers, and this may necessitate the locating of emissions systems farther from 

exhaust manifolds, thereby increasing catalyst lightoff delays.

Although we agree to a certain extent about the performance of gasoline-fueled 

HDVs at high altitudes and their similarity to LDVs, the comments did not alter our view 

that the compliance margins provided in the HDV FTP bin standards compared to what 

the control technologies can achieve, and the freedom manufacturers have to shift to the 

more stringent bins gradually as the program phases in, are adequate to account for these 

effects at altitude. The manufacturers provided no data to counter this view. 

We note that our adoption of relaxed interim in-use standards for vehicles in these 

bins will be directionally helpful to address any remaining concerns by manufacturers 

regarding emissions at altitude (Section IV.B.6.a). This is because testing at high 

altitudes is often not required for certification (typically manufacturers use an 

engineering analysis instead), and thus the relaxed in-use standards will help to facilitate 

Tier 3 implementation for any HDV designs in which in-use problems at high altitudes 

surface in the initial model years.

C. Evaporative Emissions Standards

Gasoline vapor emissions from vehicle fuel systems, which are a mixture of 

hydrocarbon compounds, occur when a vehicle is in operation, when it is parked, and 

when it is being refueled. Evaporative emissions which occur daily from gasolinepowered vehicles are primarily functions of air and fuel temperature, fuel vapor pressure, 

and vehicle driving. EPA first instituted evaporative emissions standards in the early 

1970s to address hydrocarbon emissions when vehicles are parked after being driven. 

These are commonly referred to as hot soak and diurnal emissions. Over the subsequent 

years the test procedures have been modified and improved, the standards have been 

revised to be more stringent, and we have addressed emissions which arose from new 

fuel system designs by establishing new requirements such as running loss emission 

standards and test procedure provisions which address resting losses (e.g., permeation). 

Onboard refueling vapor recovery (ORVR) requirements for control of refueling 
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emissions first began to phase-in for light-duty vehicles (LDVs) and light-duty trucks 

(LDTs) in the 1998 MY. These were later expanded to cover medium-duty passenger 

vehicles (MDPVs) and some heavy-duty gasoline vehicles (HDGVs). 

Even though evaporative and refueling emission control systems have been in 

place for most of these vehicles for many years, evaporative emissions still contribute 30-

40 percent of the on-road mobile source hydrocarbon inventory. The rate of these 

emissions in grams/day (hot soak and diurnal), grams/mile (running loss) or grams per 

gallon (refueling) depends on (1) the stringency of the applicable emission standards, (2) 

ambient and fuel temperature, (3) fuel vapor pressure, and (4) the presence/ state of 

repair of the fuel/evaporative control system. 

These fuel vapor emissions are ozone and PM precursors, and also contain air 

toxics such as benzene. Even though there are mature evaporative emission control 

programs in place, further hydrocarbon emission reductions are needed and can be 

achieved from further evaporative emission controls on gasoline-powered highway motor 

vehicles. 

This section discusses the vehicle evaporative emission standards and related 

provisions for LDVs, LDTs, MDPVs, and HDGVs. The evaporative emissions program 

has six basic elements: (1) the early allowance program (MY 2015-2016), (2) the 

transitional program (MY 2017), (3) the Tier 3 evaporative emission phase-in program 

(MY 2018-2021), (4) the fully phased-in standards (MY2022+), (5) requirements for 

HDGVs including ORVR for the 2018MY, and (6) a leak standard and test procedure 

which become mandatory for Tier 3 vehicles in the 2018MY. As discussed below, we 

are finalizing more stringent standards that will apply for the 2- and 3- day evaporative 

emissions tests, a canister bleed test procedure and emission standard, and a new 

certification test fuel specification.342 As discussed in section IV.D, we are also adding a 

fuel/vapor system leak standard and test procedure for LDVs, LDTs, and MDPVs. EPA is 

not changing any existing light-duty running loss or refueling emission standards with the 

Tier 3 FRM, with the exception of the certification test fuel specification and the addition 

of a refueling emission controls for complete HDGVs over 10,000 lbs gross vehicle 

weight rating (GVWR). This section also describes phase-in flexibilities, credit and 

allowance programs, and other issues related to evaporative emissions control. 

In this rule, the vehicle classifications, LDVs, LDTs, MDPVs, and HDGVs, 

remain unchanged from Tier 2 (see 40 CFR 86.1803-010). For purposes of this 

discussion of the Tier 3 evaporative emissions program, the vehicle standards can be 

further placed in four categories: (1) “zero evaporative emission” PZEV vehicles certified 

by CARB as part of the ZEV program, (2) vehicles certified by CARB to meet LEV III 

evaporative emission program requirements on CARB certification fuel (7 RVP E10) as 

 

342 Certification fuel provisions for evaporative and refueling emissions testing for flexible fuel vehicles 

(FFVs) are discussed separately below.
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early as 2014 MY, (3) vehicles meeting the Tier 3 evaporative emissions program 

requirements using the Tier 3 certification test fuel (9 RVP E10), and (4) transitional 

vehicles meeting existing EPA evaporative requirements on Tier 2 certification test fuel 

(9 RVP E0).343,344 For ease of reference these four categories may be referred to as 

PZEV evap, LEV III evap, Tier 3 evap, and Tier 2/MSAT evap in this section.345

1. Tier 3 Evaporative Emission Standards 

a. Final Standards

The Tier 3 program for evaporative emissions builds on previous EPA 

requirements as well as the evaporative emissions portion of CARB’s recent LEV III rule 

which starts mandatory phase-in with the 2018 MY. The level of the standards, the 

timing of their implementation, and related provisions are designed in great measure to 

allow manufacturers to design, certify, and build one control system for each 

evaporative/refueling family to meet CARB and EPA requirements so that these vehicles 

can be sold in all 50 states. Commenters supported this approach and no commenter 

opposed the stringency or timing of the evaporative emission standards and related test 

procedures. We believe the program is appropriate since it will require new more 

stringent evaporative emissions control technology in new vehicles and also achieve 

improved in-use system performance. 

Section IV.C.1.a.i, which follows, describes the basic emission standard levels for 

LDVs, LDTs, MDPVs, and HDGVs. Section IV.C.1.a.ii, describes a new canister bleed 

standard and testing requirement for measuring emissions from the evaporative canister. 

Section IV.C.1.a.iii discusses the optional use of the CARB LEV III Option 1 evaporative 

emission standards during a transition period. Next, Section IV.C.1.a.iv discusses interim 

use of CARB PZEV zero evap data based on CARB Phase II fuel. Finally section 

IV.C.1.a.iv, discusses the ongoing requirement to meet running loss emission standards.

i. Hot Soak Plus Diurnal Standards

 The Tier 3 hot soak plus diurnal emission standards are designed to bring into 

the broader motor vehicle fleet the “zero evap” technology used by the manufacturers in 

their partial zero emission vehicles (PZEVs). Manufacturers developed this “zero evap” 

technology as part of their response to meeting the requirements of the CARB Zero 

Emission Vehicle (ZEV) program. This program, which is in effect in 11 other states, 

 

343 We adopted the most recent vehicle evaporative emission standards for LDVs, LDTs, and MDPVs in 

2007 (72 FR 8428, February 26, 2007). The most recent standards for HDGVs were adopted in 2000 (66 

FR 5165, January 18, 2001). 

344 See Section IV.F for a discussion of the final certification fuel provisions, including discussion of 

options for and implications of the certification test fuel having 10 percent ethanol.

345

 “PZEV evap” as discussed here refers only to the evaporative emission and useful life requirements of 

the PZEV program, not the exhaust emission requirements.
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allows manufacturers to meet their ZEV mandate percentages (totally or in-part) by the 

use of vehicles which among other characteristics have very low fuel vapor emissions. 

The hot soak plus diurnal emission standards we are adopting (presented in Table 

IV-19) are designed to be met with technology that limits Tier 3 vehicles to essentially

zero fuel vapor emissions. For the Tier 3 evaporative emissions program, we are not 

changing the basic 2-and 3-day evaporative emission test procedures other than the 

certification fuel requirements. The level of the standards primarily accommodates what 

is often referred to as new vehicle background hydrocarbon emissions. These emissions 

arise from the off-gassing of volatile hydrocarbons from plastics, rubbers, and other 

polymers found in new vehicles (e.g., new tires, interiors, seats, fuel system components, 

paints, and adhesives). In the field these emissions decrease over time as the vehicle 

ages, but this cannot necessarily be replicated in the time that manufacturers typically

allocate for vehicle certification or with the techniques normally used for vehicle preconditioning. Provisions related to vehicle pre-conditioning before evaporative emissions 

certification testing are discussed further below. 

In the past EPA has set relatively uniform (but not identical) evaporative emission 

standards for LDVs and LDTs and somewhat higher values for MDPVs and HDGVs. 

The Tier 3 hot soak plus diurnal emission standards follow this approach, because in 

general the vehicles have higher levels of non-fuel background emissions as they get 

larger. 

 As described in more detail in Section IV.C.2.d below, EPA is finalizing a 

program that will allow manufacturers to demonstrate compliance with the hot soak plus 

diurnal evaporative emission standards using averaging concepts. A manufacturer may

comply by averaging within each of the four vehicle categories but for the reasons 

discussed below, may not rely on averaging across categories. The technical approaches 

to meeting the standards are discussed in Section IV.C.2. 

Table IV-19 Final Evaporative Emission Standards (g/test)a,b,c

Vehicle Category/Averaging Sets Highest Hot Soak + Diurnal Level

(over both 2-day and 3-day diurnal tests)

LDV, LDT1 0.300

LDT2 0.400

LDT3, LDT4, MDPV 0.500

HDGVs 0.600

a The standards are in grams of hydrocarbons as measured by flame ionization detector during the diurnal 

and hot soak emission tests in the enclosure known as the sealed housing for evaporative determination 

(SHED).

b Note that the standards are the same for both tests; existing standards are slightly different for the 2- and 

3-day tests.

c Vehicle categories are the same as in EPA’s Tier 2 final rule; see 65 FR 6698, February 10, 2000. 

ii. Canister Bleed Emission Standard
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In addition to more stringent hot soak plus diurnal standards, EPA is finalizing a 

new canister bleed emission test procedure and standard as part of the Tier 3 program. 

The canister bleed test procedure is described in Section IV.C.6 below. EPA is adopting 

the canister bleed standard because it is an important tool in moving Tier 3 evaporative 

emissions control toward zero fuel vapor emissions. No commenter opposed the canister 

bleed standard or commented on the test procedure. The new test and standard align with 

the California LEV III requirements and help to ensure that near-zero fuel vapor 

emissions are being emitted by vehicles from the fuel tank through the evaporative 

emission canister. Manufacturers will be required to measure diurnal emissions over the 

2-day diurnal test procedure from just the fuel tank and the evaporative emission canister 

using Tier 3 certification fuel and comply with a 0.020 g/test standard for all LDVs, 

LDTs, and MDPVs and 0.030 g/test for HDGVs. The feasibility of this standard is 

discussed in Section IV.C.3 below. The canister bleed test and standard drives canister 

design elements such as total gasoline working capacity, internal architecture, and the 

type of carbon used. These are also key elements of canister design for the hot soak plus 

diurnal emission standards. 

The canister bleed standard will be implemented differently than the hot soak plus 

diurnal standard. EPA is not applying the averaging program to this new bleed test 

standard as compliance is relatively straightforward and low in cost. Therefore, each 

evaporative/refueling emission family certified by manufacturers will need to 

demonstrate compliance with their respective standard. As discussed below, the canister 

bleed standard will not apply at high altitude, but proportional control is expected. Since 

the performance of the canister is also evaluated in the hot soak plus diurnal evaporative 

emissions sealed housing for evaporative determination (SHED) test the canister bleed 

emission standard will not be included in the In-Use Verification Program of under 40 

CFR 86.1845 through 1853, but it must be met in use. We will not have canister bleed 

specific family criteria for certification but the test will have to be completed and the 

standard met for each evaporative/refueling family including potentially twice if there are 

two canisters used. A deterioration factor will not be required, but the manufacturer must 

certify that the standard will be met for the full useful life. As mentioned above, the 

standard will have to be met in-use and could be evaluated in EPA confirmatory testing.

The canister bleed standard will have to be met using the same fuels and test 

procedures used for the hot soak plus diurnal standards. We will accept results on either 

CARB or EPA test fuels/test temperatures for the canister bleed test provided the same 

are used for the hot soak plus diurnal test. 

iii. Hot Soak Plus Diurnal Standard with the Fuel System Rig Test 

As part of its LEV III program, CARB has included an alternative set of 

evaporative emission standards, referred to as Option 1 standards. These are shown in 

Table IV-20. 
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Table IV-20 CARB Option 1 Evaporative Emission Standards

Vehicle Category

Highest Hot Soak + 

Diurnal Level (over both 2-

and 3-day diurnal tests) 

(g/test)

Running Loss

(g/mile)

Vehicle 

SHED

Rig

SHED

Passenger Car 0.350 0.0 0.05

LDT < 6,000 lbs GVWR 0.500 0.0 0.05

All other vehicles > 6,000 

lbs GVWR 0.750 0.0 0.05

The Option 1 standards include evaporative emission standards (hot soak plus 

diurnal) that are slightly higher numerically than our final standards. Vehicles certified 

under this option may not use averaging in the CARB LEV III program because they

basically represent the same evaporative emission standards as exist for PZEVs under 

CARBs ZEV program wherein averaging is not permitted. Option 1 also includes an 

additional SHED test of the vehicle fuel system (rig test) that pre-dates development of 

the canister bleed emission standard. The rig SHED test is discussed in Section IV.C.6. 

From a practical perspective, this test is more difficult to conduct than the bleed test 

discussed above and is intended to force manufacturers to demonstrate at certification 

that their stand alone (not in chassis) fuel/vapor control system designs have < 54 mg fuel 

vapor emissions.346 While one commenter was in favor of permanently including Option 

1 in the EPA final rule based on what it viewed to be favorable pre-production 

engineering design features of the rig SHED test, EPA is including Option 1 only as 

interim compliance alternative for a limited period of time but not as a permanent option 

in the Tier 3 evaporative emission program. While we see the value to vehicle 

manufacturers of the rig SHED test as an engineering design and development tool, by its 

very nature, the rig SHED test and standard is not implementable as an enforceable 

standard because a fuel system cannot be removed from a vehicle and reconstructed in a 

SHED for testing without compromising its fundamental structural and mechanical 

integrity as it existed on the vehicle. We believe that the hot soak plus diurnal SHED 

test and standard and the canister bleed test and standard will accomplish the objective of 

keeping fuel vapor emissions to a minimum while doing so in an enforceable manner. 

EPA believes most manufacturers will prefer to certify to the averaging based 

standards in Table IV-1 (similar in stringency and program construct to CARB Option 2). 

However, because some manufacturers may have vehicle models meeting the CARB 

 

346 Any value < 54mg rounds down to zero under the regulations.
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Option 1 standards and emission requirements now or in the near future, EPA will allow 

compliance with the CARB Option 1 standards as an acceptable interim alternative to 

compliance with the Tier 3 evaporative emission standards if the model is certified by 

CARB to LEV III requirements before the 2017 MY. These vehicles could then be 

certified using carryover provisions through the 2021 MY as part of the evaporative 

emissions phase-in described below. This is two model years longer than in the proposal, 

but this extension is reasonable given the life cycle of most fuel/vapor control systems 

and the goal of aligning with the LEV III program for a national program where 

possible.347 As noted in the following sections, vehicles certified under this provision 

will count toward the phase-in percentage requirements and could earn allowances as 

discussed below, but the vehicles will not be eligible to earn or use credits for the 

evaporative emissions averaging program. Carryover vehicles will have to meet the EPA 

leak standard and the high altitude emission standard to be counted toward the sales 

percentage requirements for 2018 and later model years.

iv. Interim Carryover of PZEV Evap Data for Tier 3 Certification

To earn credits toward compliance with the CARB Zero Evaporative Emissions 

(ZEV) program requirements, many manufacturers have certified LDVs and LDTs to 

150,000 mile useful life emission standards similar to those found in Table IV-20. These 

vehicles have used CARB Phase II fuel (E0) and met the rig SHED test requirement in 

lieu of the canister bleed standard, but otherwise have employed the same basic 

technology EPA expects for the LEV III and Tier 3 programs. EPA is permitting data 

generated from certification of these vehicles in the 2015 and 2016 MYs to be used for 

Tier 3 evaporative emissions purposes through the 2021 MY.

v. Running Loss Emission Standards

EPA has required vehicles to meet running loss emission standards since the 1996 

model year. These requirements, which are specified in 40 CFR 86.134-96, apply to all 

gasoline-powered highway motor vehicles. EPA is not changing either the test 

procedures or emission standard for the running loss test. However, the change in 

certification test fuel will apply to testing for such standards. This is appropriate based 

on the rationale for implementing a certification fuel change and is necessary since the 

running loss test is part of the overall test sequence for the 3-day hot soak plus diurnal 

test. EPA does not anticipate that the change in certification test fuel will impact the 

stringency of the running loss test and standards or the manufacturers’ ability to comply 

as part of Tier 3.

 

347 EPA is incorporating by reference the CARB Option 1 test procedures and emission standards for this 

interim period. 
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b. High-Altitude Requirements

Prior to this rule, the most recent vehicle evaporative emission standards were 

adopted in 2007.348 The new standards adopted in 2007 apply only to testing under lowaltitude conditions.349

 In the 2007 rule, we decided to continue to apply the previous 

“Tier 2” standards for testing under high-altitude conditions. This was necessary to 

achieve an equivalent level of overall stringency for high-altitude testing, accounting for 

the various effects of altitude and lower atmospheric pressure on vapor generation rates, 

canister loading and purging dynamics, and other aspects of controlling evaporative 

emissions due primarily to lower air density and vapor concentrations at altitude. While 

it is important for vehicles to have effective emission controls at high altitudes, we do not 

want the high-altitude standards and test procedures to dictate the fundamental design of 

the Tier 3 evaporative emission control systems since the high altitude vehicle population

is only about five percent of the national total. Therefore, we believe it is appropriate to 

address this goal by applying the current 2-day low altitude evaporative emission 

standards and requirements for high-altitude testing.350 The vehicle categories for the 

high altitude standards in this rule are the same as for the low altitude standards. The 

standards are presented below in Table IV-21. This will both reduce evaporative 

emissions at high altitude and again create a requirement to confirm that emission 

controls function effectively at high altitude without forcing manufacturers to apply

altitude-specific technologies. The leak standard presented in Section IV.D below will 

apply equally at low and high altitude testing as compliance is not dependent on air 

density and vapor concentrations.

Table IV-21 Final High-Altitude Evaporative Emission Standards (g/test)

Vehicle Category Highest Hot Soak + Diurnal Level

(over both 2-day and 3-day tests)(g/test)

LDV, LDT1 0.65

LDT2 0.85

LDT3, LDT4 1.15

MDPV 1.25

HDGVs < 14,000 lbs GVWR 1.75

HDGVs > 14,000 lbs GVWR 2.3

 

348 See 72 FR 8428 (February 26, 2007).

349 Low altitude conditions means a test altitude less than 549 meters (1,800 feet). High-altitude conditions 

means a test altitude of 1,620 meters (5,315 feet) plus or minus 100 meters (328 feet) or equivalent 

observed barometric test conditions of 83.3 kPa (24.2 inches Hg) plus or minus 1kPA (0.30 inches Hg) See 

40 CFR 86.1803-01.. 

350 See Control of Air Pollution from New Motor Vehicles: Heavy-Duty Engine and Vehicle Standards and 

Highway Diesel Fuel Sulfur Control Requirements 66 FR 5002, January 18, 2001and Control of Hazardous 

Air Pollutants from Mobile Sources, 72 FR 8428, February 26, 2007.
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A few additional points should be noted about our Tier 3 high altitude evaporative 

emissions control program. First, EPA does not expect manufacturers to produce 

vehicles with high-altitude only evaporative control systems. Given the nature of 

evaporative emission control technology, there should be emission reductions at high 

altitude proportional to those achieved at lower altitudes. We are not applying the canister 

bleed test and emission standard at high altitude, but we expect similar emission 

reductions to those which will occur at low altitude. These vehicles will have to meet the 

canister bleed emission standard at low altitude and canister bleed emission reductions at 

high altitude should be proportional as is the case with the low altitude hot soak plus 

diurnal standards. Any adjustment to meet the standard at high altitude to account for 

canister adsorption and desorption effects of higher altitudes would result in 

fundamentally the same technology with an increase in the testing burden but not 

necessarily more emissions control. Therefore, we believe the low-altitude canister bleed 

test is sufficient for achieving the level of emission control for operation in both lowaltitude and high-altitude conditions. Second, for vehicles certified with FELs above or 

below the applicable standard for testing at low altitude, the same differential will apply

to the FELs for high-altitude. For example, if an LDV was certified with an FEL of 

0.400 g instead of the 0.300 g standard, the high-altitude FEL will be 0.75 g 

(0.65g+0.10g). This high-altitude FEL will not be used for any emission-credit 

calculations, but it will be used as the emission standard for compliance purposes. Third, 

gasoline RVP for certification test fuel will be set at 7.8 RVP with 10 percent ethanol, as 

specified in Section IV.F. Finally, we are finalizing a minor adjustment to the high 

altitude test procedures. The existing 2- and 3-day test procedures apply equally at low 

and high altitude. We are keeping the same basic requirement but will allow for a 

downward adjustment of 5 °F in the temperatures related to the running loss test within 

the 3-day test cycle. Thus, the applicable ambient temperatures at §86.134-96 (f) and (g) 

will be 90±5 °F instead of 95±5 °F for high altitude testing, and the entire fuel 

temperature profile from §86.129-94(d) shifts down by 5°F. EPA believes this is 

appropriate given the differences in atmospheric conditions at low versus high altitude 

and will still result in equivalent control of running loss emissions at higher altitudes. 

EPA requested comment on the alternative approach of keeping test temperatures the 

same, but omitting the 3-day test cycle for testing at high altitude. This was supported by

one set of commenters, but at this time EPA does not have the data needed to drop such a 

fundamental test requirement.

As mentioned above, emission data from vehicles meeting the current CARB 

PZEV zero evap and CARB LEV III Option 1 requirements could be used to qualify that 

vehicle to meet the Tier 3 evaporative emission regulations for the 2017-2021 MYs. To 

qualify for a federal certificate, the vehicle will also have to meet the Tier 3 high altitude 

evaporative emission requirements. CARB does not require vehicles to meet EPA high 

altitude requirements, so for these vehicles we are giving the manufacturers the option to 

certify either by providing SHED test data or based on an engineering demonstration 

using data and analysis and the application of good engineering judgment. For the 2015-
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2017MYs, manufacturers can use data based on either Tier 2 or Tier 3 test fuel. 

Beginning in the 2018 model year, for Tier 3 vehicle certification to the high altitude 

standard, the data must be based on Tier 3 fuel. 

c. Useful Life 

Trends indicate that vehicle lifetimes are increasing. It is important that emission 

control systems be designed to meet requirements while vehicles are in use. As discussed 

in Section IV.A.7 and IV.B.6 of this preamble, along with the new emission standards, 

we are finalizing a longer useful life of 150,000 miles/15 years, whichever comes first, 

for LDTs up to 6,000 lbs GVWR but over 3,750 lbs loaded vehicle weight (LVW) 

(LDT2s), all LDTs over 6,000 lbs GVWR (LDT3/4), MDPVs, and HDGVs. The longer 

useful life will apply to all certifications to the Tier 3 evaporative emission standards (see 

Table IV-19 and Table IV-20 above). For an evaporative/ refueling family certified to 

150,000 miles/15 year useful life for evaporative emissions this useful life will also apply

to the hot soak plus diurnal, running loss, canister bleed, fuel system rig, refueling, leak, 

and high altitude standards. All of these standards impact the fuel and vapor control 

systems and it is technologically consistent to require the same useful life for these 

standards because they all rely on the mechanical integrity, durability, and operational 

performance of the same components in the evaporative emissions control system. 

Due to limitations in the CAA, for LDVs and for LDTs up to 6,000 lbs GVWR 

and at or below 3,750 lbs LVW (LDT1s), we are keeping the current useful life of 

120,000 miles/10 years unless, as described in Section IV.A.7, a manufacturer elects 

alternative exhaust emission requirements that are associated with 150,000 mile/15 year 

useful life for these vehicles. For manufacturers that select those optional standards, the 

useful life of 150,000 miles/15 years will apply for all Tier 3 evaporative emission 

requirements as listed in the previous paragraph. 

During the early, transition, and phase-in program periods and until the final year 

of the allowed phase-in period for the Tier 3 evaporative emission program (MY 2015-

2021) the differences between the exhaust and evaporative emission phase-in programs 

presents the possibility that in some cases a manufacturer could certify a model to the 

Tier 3 exhaust requirements (or CARB equivalents) but not necessarily to the Tier 3 

evaporative emission requirements.351 In those situations, the final rule provides that a 

family could have a 150,000 miles/15 years useful life for exhaust emissions but maintain 

the current useful life for all of the evaporative and refueling emission standards since the 

vehicle does not yet meet Tier 3 evaporative emission requirements. During the phase-in 

period, if a family is certified to the Tier 3 evaporative emission requirements but not yet 

 

351 By the 2022 MY, all Tier 3 evaporative system emissions certifications must use Tier 3 certification test 

fuel and test procedures or equivalent CARB test procedures, certification and emission standards. This 

affects evaporative (hot soak plus diurnal), running loss, and canister bleed emission standards certification. 

Refueling, spit back and leak standards are only to be met using Federal certification test fuel.
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certified for Tier 3 exhaust emission requirements, then the useful life could be 150,000 

miles/15 years for evaporative and refueling emissions standards but the existing useful 

life for exhaust emissions. However, by the 2022 MY the useful life for all of these 

requirements will be 150,000 miles/15 years for LDT2/3/4s, MDPVs, and HDGVs since 

by that model year all vehicles must be certified using Tier 3 certification fuel and test 

procedures and meet Tier 3 evaporative emission standards or CARB equivalents.352

OBD regulations call for the systems to operate effectively over the useful life of 

the vehicle. We are not changing that requirement, but rather want to clarify that during 

the early, transition, and phase-in years of the program (MY 2015-2021), all of the OBD 

monitoring requirements have the same useful life as that for the exhaust emission 

standard except for the evaporative system leak monitoring requirement which has the 

same as that required for the evaporative and refueling emission standards control 

systems.

d. What Requirements Must a Vehicle Meet to Qualify as a Tier 3 Vehicle for 

Evaporative Emissions?

As mentioned above, there are three different revised or new evaporative emision 

requirements applicable to Tier 3 vehicles. These are the hot soak plus diurnal standards, 

the canister bleed standard, and the leak standard. In addition the refueling, running loss, 

and spit back standards are unchanged but will have to be met on Tier 3 certification fuel. 

Compliance with these requirements is potentially complicated by the fact that the CARB 

ZEV and LEVIII programs will bring zero evap technology into the market place before 

or at the same time that Tier 3 implementation begins but with test fuel and test procedure 

differences. In order to qualify as a Tier 3 vehicle for evaporative emission purposes the 

vehicle must meet all applicable requirements on the specified fuel. Unless otherwise 

specified (e.g., HDGV refueling spit back), if a vehicle does not meet all evaporative 

emission program requirements, including both the applicable standards and test fuel then 

it does not qualify as a Tier 3 vehicle for evaporative emission purposes. Table IV-4, 

below summarizes the requirements that vehicles in various categories must meet to 

qualify as a Tier 3 vehicle for evaporative emission purposes as a function of model year. 

The entries in the cells of the table specify the required test fuel. The table is for 

reference of the reader in reviewing subsequent sections of this preamble. Refer to the 

regulatory text for specific requirements for the various programs.

 

352 The only exception here will be for vehicles not meeting Tier 3 evaporative emission requirements in 

the 2022 MY as a result of the use of previously earned allowances.
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Table IV-22 Requirements for Vehicle to Qualify for Tier 3 Evaporative Emissions 

Program and Test Fuel Requirements

Model 

Year

Program/ 

Zero Evap 

Stds

HS+DI/ 

Running 

Loss

Rig Canister 

Bleed

Leak 

(except 

HHDGV)*

High Altitude 

& Refueling/ 

Spit back **

 MY 2017 TRANSITION PROGRAM

2017 Percentage 

- PZEV 

zero evap

(carryover)

CA Ph. 2 CA 

Ph. 

2

N/A N/A EPA Tier 2 or 

Tier 3 

2017 Percentage 

- LEV III 

Opt. 1

CA Ph. 3 CA 

Ph. 

3

N/A N/A EPA Tier 3 

2017 Percentage 

- LEV III 

Opt.2 

CA Ph. 3 N/A CA Ph. 3 N/A EPA Tier 3

2017 Percentage 

- Tier 3

Tier 3 N/A EPA Tier 

3

N/A EPA Tier 3

2017 PZEV zero 

evap only 

(carryover)

CA Ph. 2 CA 

Ph. 

2

N/A N/A EPA Tier 2 or 

Tier 3

2017 20/20-

PZEV zero 

evap

(carryover)

CA Ph. 2 CA 

Ph. 

2

N/A EPA Tier 3 EPA Tier 2 or 

Tier 3 

2017 20/20- LEV 

III Opt. 1 

CA Ph. 3 CA 

Ph. 

3

N/A EPA Tier 3 EPA Tier 3

2017 20/20 -

LEV III 

Opt. 2

CA Ph. 3 N/A CA Ph. 3 EPA Tier 3 EPA Tier 3

2017 20/20 - Tier 

3

Tier 3 N/A EPA Tier 

3

EPA Tier 3 EPA Tier 3

 MY 2018-2021 PHASE-IN PROGRAM

2018-

2019

PZEV zero 

evap 

(carryover)

CA Ph. 2 CA 

Ph. 

2

N/A EPA Tier 2 

or Tier 3

EPA Tier 2 or 

Tier 3 

2018-

2021

LEVIII 

Opt.1

CA Ph. 3 CA 

Ph. 

3

N/A EPA Tier 3 EPA Tier 3

2018- LEVIII CA Ph. 3 N/A CA Ph. 3 EPA Tier 3 EPA Tier 3
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

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2021 Opt. 2

2018-

2021

Tier 3 Tier 3 N/A EPA Tier 

3

EPA Tier 3 EPA Tier 3

 MY 2022+ FULLY PHASED-IN PROGRAM

2022+ LEV III 

Opt. 2

CA Ph. 3 N/A CA Ph. 3 EPA Tier 3 EPA Tier 3

2022+ Tier 3 Tier 3 N/A EPA Tier 

3

EPA Tier 3 EPA Tier 3

* LHDGVs are heavy-duty gasoline vehicles with a GVWR equal to or less than 14,000 lbs; HHDGVs 

are heavy-duty gasoline vehicles with a GVWR in excess of 14,000 lbs.

** Incomplete HDGVs without ORVR may defer demonstrating compliance with the spit back 

requirement on Tier 3 fuel until the 2022 MY.

2. Program Structure and Implementation Flexibilities 

a. Percentage Phase-In Requirements

As proposed, the final Tier 3 evaporative emission standards will be phased in 

over a period of six MYs 2017-2022. Manufacturers supported the proposed phase-in 

schedule and there were no issues raised with regard to lead time for any vehicle class. 

As discussed below, there will be three options for the 2017 MY. For the 2018-2019 

MYs, the requirement will apply to 60 percent of a manufacturer’s nationwide sales of all 

LDVs, LDTs, MDPVs, and HDGVs (including vehicles sold in California and the section 

177 states). This will increase to 80 percent for MYs 2020 and 2021 and by MY 2022 it 

will apply to 100 percent of sales in these four categories. Beginning in MY 2018 any

vehicle included in the percentage phase-in, except vehicles that had earned allowances, 

will have to meet the leak standard discussed in section IV.D.

 Evaporative emission requirements for the MY 2017 apply only to LDVs, 

LDT1s, and LDT2s as defined in 40 CFR 86.1803-01. To be consistent with the start 

date for Tier 3 exhaust standards, phase-in requirements will not include vehicles over 

6,000 lbs GVWR until the 2018 MY. The manufacturers will have three options. The 

first, which we are calling the “primary” or “percentage” option, requires that a value 

equal to 40 percent of a manufacturer’ s LDVs, LDT1s, and LDT2s sold outside of 

California and the states that have adopted the CARB ZEV or LEV III programs must 

meet the Tier 3 evaporative emission requirements on average. The 40 percent is 

calculated based on vehicles at or below 6,000 lbs GVWR but compliance can be based 

on vehicles regardless of their GVWR. The second which we are calling the “PZEV zero 

evap only” option, requires a manufacturer to sell all of the LDVs, LDT1s, and LDT2s 

certified with CARB as meeting the PZEV evaporative emission requirements (zero 

evap) in MY 2017 throughout all of the U.S. and not to offer for sale any non-PZEV zero 

evap version of those specific vehicle models/ configurations in any state whose vehicles 

are covered by the Tier 3 evaporative emission standards. Thus, this will apply to sales in 

any state except for California and states that have adopted the CARB ZEV or LEV III 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

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programs under section 177 of the Clean Air Act. Under this second option, no tracking 

of sales or end of year compliance calculation will be required. Some manufacturers may

find this option attractive, as they have more limited product offerings and find tracking 

of production and sales more difficult. The third option, which we are terming the 20/20 

option, requires that 20 percent of a manufacturer’s LDVs, LDT1s, and LDT2s (e.g., 

equal to or less than 6,000 lbs GVWR) sold outside of California and the states that have 

adopted the CARB ZEV or LEV III programs meet the Tier 3 evaporative emission 

requirements on average and that this 20 percent or another 20 percent of vehicles in the 

three groups listed above meet the leak standard discussed in section IV.D. Each 

percentage requirement must be met, (i.e., there is no flexibility to permit meeting 

shortfalls of the hot soak plus diurnal or leak standard percentages with higher values 

from the leak standard category). However, as was the case with the 40 percent option 

above, compliance can be based on vehicles regardless of their GVWR. The third option 

was supported by several commenters as a means to address 2017 MY transition issues 

related to phase-out of current products and phase-in of future products. EPA believes 

that for these vehicles the leak standard will provide emission reduction benefits 

comparable in magnitude to the Tier 3 evaporative emission standards. Thus, under this 

approach, the manufacturers’ product transition concerns can be addressed while 

achieving the overall evaporative emission reductions from 2017 MY vehicles. It should 

be noted that these vehicles must also meet the 0.020 inch evaporative system leak 

monitoring requirement which also takes effect in the 2017 model year.

As discussed below, beginning in the 2018 MY, to be counted toward the 

percentages needed to meet the Tier 3 phase-in percentages (e.g., 60% in 2018 and 2019 

MYs) a Tier 3 compliant vehicle must also meet the leak standard. 

At the time of certification, manufacturers will identify which families will be 

included in their Tier 3 evaporative emission percentage calculations (this could be 

families above or below the individual Tier 3 evaporative emission standards for the 

given class of vehicles (Table IV-19) as well as vehicles meeting CARB’s PZEV zero 

evap or LEV III Option 1 standards (Table IV-20) and could also include earned 

allowances as discussed below. The manufacturers will use projected sales information 

for these families plus allowances as desired and available, to show how they expect to 

meet the phase-in percentage requirements for the model year of interest. At the end of 

the model year reconciliation the manufacturers will be expected to show that the 

percentages were met. If the percentages are not met, the manufacturers will either use 

additional allowances and/or bring more vehicle families/vehicles into the calculation 

until the sales percentage is met. This step is being required because the initial 

demonstration of compliance with the fixed percentage at certification is based on 

projected sales. If the manufacturers did not have to demonstrate that the fixed 

percentages were met, the percentage would then be a goal and not a requirement and 

there would be no means to capture the emission reduction shortfalls. This step is unique 

to the evaporative emission program relative to the NMOG+NOx and PM programs 

because the evaporative program involves both fixed percentages and ABT. The 
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NMOG+NOx program involves ABT but does not involve fixed percentages and the PM 

program involves fixed percentages but does not involve ABT. 

 The additional vehicles added to meet the percentage could only be meeting the 

Tier 2 hot soak plus diurnal requirements. In this case, use the larger of the 2- or 3- day

hot soak plus diurnal certification emission levels. Adding these vehicle families/vehicles 

into the calculations (discussed below) may result in a credit deficit for that model year 

for a given averaging set. A manufacturer could not have an unresolved deficit for more 

than three consecutive model years as discussed below. The deficit would have to be 

eliminated with positive credits not later than the ABT calculation and credit 

reconciliation which occurs after the fourth model year. 

As discussed above for exhaust emissions, while unlikely, it is possible that a 

manufacturer could in its annual certification preview meeting with EPA, indicate that its 

technology mix is such that it will have a credit deficit when the sales percentages 

requirement is met. This could occur if the fleet average evaporative emission value for 

Tier 3 vehicles did not meet the Tier 3 hot soak plus diurnal standard for the Tier 3 

vehicles in any given averaging set. Also, a manufacturer could have a deficit from a 

previous model. In these situations, certifying with a projected or actual deficit would 

require EPA approval after submission of a plan from the manufacturer which explains 

how it will eliminate the deficit within the model years permitted. Even if a manufacturer 

had projected or actual deficits for two or three consecutive model years, all accrued 

deficits would have to be eliminated by the reconciliation which occurs after the fourth 

model year. Within this plan, which would have to be submitted and approved at each 

annual certification preview meeting, EPA would expect to see progress toward 

compliance as indicated by such factors as improved emissions performance for future 

test groups, a substantiated trend toward a more favorable fleet technology sales mix, no 

backsliding in projected fleet average values, and perhaps other situation specific criteria. 

Requiring a showing at the time of certification based on projected sales requires 

due diligence by the manufacturers and EPA, but the Tier 3 evaporative emissions 

program allows for fleet averaging, so a validation or “truing up” of these sales 

projections after the end of the model year is necessary for determining compliance with 

the requirements of the standard. This is discussed in Section IV.C.2.d.iii. As discussed 

further below, validated sales information will also be used for earning early allowances 

and to show compliance with the alternative phase-in schedule approach. 

For these purposes, vehicles included in the phase-in percentage could be: (1) 

families which certified to PZEV zero evap or CARB LEV III Option 1 requirements in 

MYs 2015 and 2016, (2) families certified to meet Tier 3 evaporative emission 

requirements, (3) any vehicle family certified to the CARB LEV III Option 2 hot soak 

plus diurnal evaporative emission standards, and (4) vehicles from the early allowance 

program. To qualify as a Tier 3 certification for evaporative emission purposes, any new 

evaporative/refueling emission family certifications will have to meet the EPA Tier 3 

certification requirements for both test procedure and certification test fuel for the 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 204 of 1039

evaporative (hot soak plus diurnal and canister bleed, running loss), refueling, and spit 

back emission standards. The leak standard will apply in the 2018 and later MYs to all 

Tier 3 vehicles except HHDGVs and those from the early allowance program. 

Furthermore, assuming the EPA provisions related to carryover of emissions data are 

met, 2015-2016 MY CARB PZEV zero evap evaporative emissions certifications could 

be carried over until the end of the 2019 MY and included as compliant vehicles within 

the Tier 3 program if they meet the other applicable Tier 3 requirements. The same is true 

for CARB LEVIII Option 1 certification, except carryover would be permitted through 

the 2021 MY if they meet the other Tier 3 requirements. See Table IV-4 for more detail 

on the program options and fuel requirements by model year. 

The phase-in percentages for MYs 2017 through 2022 reflect a percentage phasein concept applied successfully by EPA in previous rules involving evaporative and 

refueling emissions control. The phase-in provides an appropriate balance between the 

needed emission reductions and time for the manufacturers to make an orderly transition 

to the new technology on such a broad scale. The higher initial percentage here is 

appropriate because the expected evaporative emission control technology is already 

being used to varying degrees by 12 manufacturers on over 50 vehicle models today and 

is projected to gain even deeper penetration by 2017 due to the partial zero emission 

vehicles (PZEV) option within the CARB ZEV program.353

b. Alternative Phase-in Percentage Scheme

As part of program flexibility, we are allowing manufacturers to demonstrate 

compliance with the phase-in percentage requirements of the evaporative emissions 

program by using a manufacturer-determined alternative phase-in percentage scheme. 

The alternative phase-in percentage provisions allow manufacturers to use a phase- in 

more consistent with product plans such as beginning with a lower percentage(s) than 

required under the primary phase-in during the early years or to benefit from producing 

and selling more than the minimum percentage of compliant vehicles early. This 

flexibility could also be helpful in the event that a manufacturer elects to put some 

vehicles on different phase-in schedules for meeting Tier 3 exhaust and evaporative 

emission standards. As explained further below, with some limitations, allowances could 

be used toward compliance with the alternative phase-in scheme values for any given 

model year.

This approach, which was widely supported in comments by the manufacturers, 

would be available beginning in the 2017 MY for all manufacturers, except for any

manufacturer which used the “PZEV zero evap only” nationwide option for the 2017 MY 

for whom the approach would be available beginning in 2018 MY. Vehicle and fuel 

 

353See http://driveclean.ca.gov/searchresults_by_smog.php?smog_slider_value=9&x=12&y=12,(last 

accessed on December 6, 2013).
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

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eligibility requirements for the program are summarized in Table IV-23. Refer to the 

regulatory text for specific requirements.

Table IV-23 Vehicle Qualifications for 2017-2022MY Alternative Phase-in

Percentage Schemes & Test Fuel Requirements

Model 

Year

Program Zero 

Evap Stds.

HS+DI / 

Running 

Loss

Rig Canister 

Bleed

Leak (except 

HHDGV)*

High Altitude 

& Refueling/

Spit back**

2017 PZEV evap

(carryover)

CA Ph. 2 CA 

Ph. 2

N/A N/A EPA Tier 2 

or Tier 3 

2017 LEV III Opt. 

1

CA Ph. 3 CA 

Ph. 3

N/A N/A EPA Tier 3

2017 LEV III Opt. 

2

CA Ph. 3 N/A CA Ph. 3 N/A EPA Tier 3

2017 Tier 3 Tier 3 N/A EPA Tier 

3

N/A EPA Tier 3

2018-

2019

PZEV evap

(carryover)

CA Ph. 2 CA 

Ph. 2

N/A EPA Tier 2 

or Tier 3

EPA Tier 2 

or Tier 3 

2018-

2021

LEV III Opt. 

1

CA Ph. 3 CA 

Ph. 3

N/A EPA Tier 3 EPA Tier 3

2018-

2022

LEV III Opt. 

2

CA Ph. 3 N/A CA Ph. 3 EPA Tier 3 EPA Tier 3

2018-

2022

Tier 3 Tier 3 N/A EPA Tier 

3

EPA Tier 3 EPA Tier 3

* LHDGVs are heavy-duty gasoline vehicles with a GVWR equal to or less than 14,000 lbs; HHDGVs are 

heavy-duty gasoline vehicles with a GVWR in excess of 14,000 lbs.

** Incomplete HDGVs without ORVR may defer demonstrating compliance with the spit back requirement 

on Tier 3 fuel until the 2022 MY.

Under this approach, before the 2017 MY (2018MY for a manufacturer which 

used the “PZEV zero evap only” nationwide option for the 2017 MY), a manufacturer 

will present a plan to EPA which demonstrates that the sum of the products of a 

weighting factor and the percentages of their U.S. vehicle sales for each model year from 

2017 (2018) through 2022 is greater than or equal to 1280 if the program started in the 

2017 MY (or 1040 if the program started in the 2018 MY). The 1280 and 1040 

numerical values are equal to the sum of the product of the weighting factors and the 

percentage requirements for MY 2017 or 2018 start dates, respectively, as applicable 

through MY 2022. These are calculated in the following manner: 

[(6)(2017MY%)+(5)(2018MY%) +4(2019MY%)+ 3(2020MY%) +2(2021MY%) 

+(1)(2022MY%)]. The 2017 MY portion of the calculation would not be included if the 

manufacturer used the “PZEV zero evap only” nationwide option and thus started the 

alternative phase-in scheme in the 2018 MY. Under the regulations, EPA has the 

authority to question elements of the plan and to seek clarifications and potential changes 

as needed. EPA could disapprove the plan and potentially not allow the use of an 

alternative phase-in scheme for the model year of interest if the manufacturer does not 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

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present a viable explanation and rationale as to how the required numerical sum for the 

phase-in would be achieved. 

EPA also sought comment on including the 20 percent value hot soak plus diurnal 

value from the 20/20 option described above for 2017MY in this calculation. 

Manufacturers generally supported including the 2017 MY in the calculation but did not 

clearly state whether the 40 percent or 20/20 option approach or both were supported. 

EPA has decided to include both options for the 2017MY in the alternative phase-in 

percentage scheme; 40 percent as described above or 20 percent, with the stipulation that 

any vehicle used to meet the 20 percent requirement in the 2017MY would also have to 

meet the OBD evaporative leak monitoring requirements and the leak standard. In other 

words, the flexibility of using different vehicles as allowed for the 20/20 option in the 

primary phase-in scheme is not included in the alternative phase-in. Including this 

restriction avoids the complexity that would be added if two different sets of vehicles 

were allowed to meet the two elements of the 20/20 option for the 2017 MY, as in the 

primary phase-in (e.g., expanding the calculation and tracking requirements and 

incorporating leak standard compliance and OBD evaporative system monitoring as part 

of the alternative phase-in scheme). If a manufacturer’s hot soak plus diurnal value 

exceeded 20 percent then that larger value could be used in the alternative phase-in 

calculation. However, the leak standard value cannot be less than 20 percent and for the 

first 20 percent the hot soak plus diurnal and the leak must be on the same vehicle and 

that vehicle must meet the 0.020 inch OBD evaporative system leak monitoring 

requirement. Compliance would be calculated in the following manner: 

[(6)(2017MY%)+(5)(2018MY%)+(2019MY%)+3(2020MY%) + 2(2021MY%) 

+(1)(2022MY%)]. If choosing the 20/20 option approach for MY 2017, the value to be 

met or exceeded in the alternative phase-in would be 1160 which is based on substituting 

the required phase-in percentages for MYs 2017-2022 in the equation. Under this option 

as above, before the 2017 MY, the manufacturer would have to submit a plan to EPA 

which demonstrates that the sum of the products of a weighting factor and the 

percentages of their U.S. vehicle sales for each model year from 2017 through 2022 is 

greater than or equal to 1160. A manufacturer that over complies with the targets (i.e., 

1040, 1160, 1280) may not trade the excess to another manufacturer. Also, a 

manufacturer must include all of its affected products in program, not just specific 

vehicle categories or subcategories. 

A manufacturer’s alternative phase-in plan must be approved by EPA prior to the 

start of production for a given model year and will have to be reviewed with EPA each 

subsequent model year to confirm that the manufacturer’s target percentages are being 

met. This would be expected to occur at the annual certification preview meeting. 

Manufacturers not meeting their target goals must present revised plans for EPA approval 

to show how the target percentages and equivalent emission standards will be met. 

Manufacturers using the alternative phase-in percentage scheme must still show 

compliance with the hot soak plus diurnal standards in each year as discussed in Section 

IV.C.2.d.iii even if they fall short of their individual target goal percentages for a given 

year. EPA is not requiring that manufacturers include Tier 2 vehicles in the calculation 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

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for a given model year if they fall short of projections (e.g., if a manufacturer projects 

25% in a given model year but only achieves 22%) because it will have to be made up in 

a subsequent year using a lower multiplier.

c. Allowance Program

We are finalizing incentives for early introduction of vehicles compliant with the 

Tier 3 evaporative emission regulations. Manufacturers can take advantage of these 

incentives prior to MY 2018 by selling vehicles that meet the Tier 3 evaporative emission 

regulations earlier than required or in greater numbers than required. Vehicle eligibility

requirements for the allowance program are summarized in Table IV-24. Refer to the 

regulatory text for specific provisions.

Table IV-24 Vehicle Eligibility to Earn Allowances & Test Fuel Requirements

Model Year 

& Program

Vehicle 

Category

HS+DI / 

Running 

Loss

Rig Canister 

Bleed 

High 

Altitude & 

Refueling

/Spitback*

 EVAPORATIVE EMISSIONS

2015-2016

PZEV zero 

evap 

carryover

LDV, 

LDT

CA Ph. 2 CA 

Ph. 2

N/A EPA Tier 2/ 

Tier 3

2015-2016

LEV III 

Option 1

LDV, 

LDT

CA Ph. 3 CA 

Ph. 3

N/A EPA Tier 2/ 

Tier 3

2015-2016

LEVIII 

Option 2

All CA Ph. 3 N/A CA Ph. 3 EPA Tier 2/ 

Tier 3

2015-2016

Tier 3

All Tier 3 N/A Tier 3 EPA Tier 3

2017 “PZEV 

evap only”

carryover

LDT 3&4 CA Ph. 2 CA 

Ph. 2

N/A EPA Tier 2/ 

Tier 3

2017 

“Percentage” 

option -

LEVIII 

Option 1

LDT3 &4 

MDPV, 

HDGV

CA Ph. 3 CA 

Ph. 3

N/A EPA Tier 

3

2017 

“Percentage” 

option

LDT3/4 

MDPV, 

HDGV

CA Ph. 3 CA 

Ph. 3

CA Ph. 3 EPA Tier 3
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

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LEVIII - 

Option 2

2017 

“Percentage” 

option

Tier 3

LDT3/4 

MDPV, 

HDGV

Tier 3 EPA 

Tier 3

EPA Tier 

3

EPA Tier 3

2017 “20/20” 

and all MY 

alt phase-in 

schemes

Not 

available

--- --- --- ---

2018+ LDV, 

LDT, MDPV 

& HDGV

Not 

available

 ORVR***

2015-2017

Early ORVR

Complete 

HDGV>

10,000 but 

<14,000

lbs. 

GVWR

--- --- --- EPA Tier 2/ 

Tier 3

2015-2021

Early ORVR

Complete 

HDGV>

14,000

lbs. 

GVWR

EPA Tier 2/ 

Tier 3

2015-2021

ORVR

Incomplet

e HDGV 

> 8,500

lbs. 

GVWR

EPA Tier 2/ 

Tier 3

* LHDGVs are heavy-duty gasoline vehicles with a GVWR equal to or less than 14,000 

lbs; HHDGVs are heavy-duty gasoline vehicles with a GVWR in excess of 14,000 lbs.

** Incomplete HDGVs without ORVR may defer demonstrating compliance with the spit 

back requirement on Tier 3 fuel until the 2022 MY.

*** All ORVR certifications must use Tier 3 fuel by the 2022 model year

As described below, manufacturers can earn “allowances” for selling any vehicle 

meeting the Tier 3 evaporative emission program requirements as specified in Table 

IV-22 earlier than required. The vehicles may be LDVs, LDTs, MDPVs, or HDGVs. 

Specifically, the allowance program includes the following: (1) for MYs 2015 and 2016, 

any LDVs and any LDTs meeting the Tier 3 evaporative emission program requirements 

as specified in Table IV-22 which are sold outside of California and the states that have 
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adopted CARB’s ZEV or LEV III programs, (2) for MYs 2015-2017, any MDPV or 

HDGV meeting the Tier 3 evaporative emission program requirements as specified in 

Table IV-22 early and sold in any state, (3) for MY 2017, any LDT3/4 meeting the Tier 3 

evaporative emission program requirements as specified in Table IV-22 and sold outside 

of California and the states that have adopted CARB’s LEV III or ZEV programs, and (4) 

for MYs 2015-2017, any complete or incomplete HDGV with a GVWR greater than 

10,000 lbs meeting the EPA refueling emissions regulations and sold outside of 

California and the states that have adopted CARB’s LEV III program. EPA asked for 

comment on extending the ORVR requirement to all HDGVs, complete and incomplete. 

As discussed in section IV.C.4.b, we are extending ORVR to all complete vehicles over 

14,000 lbs GVWR, but are not including incomplete vehicles over 8,500 lbs GVWR in 

the ORVR requirement at this time. However, we are permitting complete vehicles over 

14,000 lbs GVWR and incomplete HDGVs meeting the refueling emission standard to 

earn allowances through the 2021 MY. Any complete or incomplete HDGV eligible to 

earn allowances for the model years and areas discussed above will earn them at a 1:1 

rate for refueling emissions compliance purposes and at a 2:1 rate for Tier 3 evaporative 

emissions purposes because the refueling emission reductions are much larger. 

Furthermore, for the 2017 MY, manufacturers choosing EPA’s “percentage” 

option (see Section IV.C.2.a) could earn allowances for sales of LDT3s, LDT4s, 

MDPVs, and HDGVs that meet the CARB LEV III or Tier 3 evaporative emission 

standards and related requirements assuming their LDV, LDT1/2 sales meet the 40 

percent requirement. Similarly, manufacturers choosing EPA’s “PZEV zero evap only”

option could earn allowances in MY 2017 for LDT3/4s, MDPVs, and HDGVs that meet 

the “PZEV zero evap” evaporative emission standards, CARB LEV III, or EPA Tier 3 

evaporative emission standards and related requirements. EPA has decided not to include 

allowances for the 2017MY for any manufacturer using the 20/20 option since it would 

involve identifying not only the vehicles exceeding the 20 percent for the Tier 3 

evaporative emission requirements but also the vehicles exceeding the 20 percent for the 

leak standard and these may be different vehicles. For both the “percentage” and “PZEV 

zero evap only” options for the 2017 model year, to avoid double counting, the 

allowances will be earned only for those vehicles sold outside of California and the states 

that have adopted CARB’s LEV III/ZEV program requirements.

 To qualify as a Tier 3 vehicle for evaporative emission allowance purposes the 

vehicle must meet the requirements summarized in Table IV-22. Manufacturers will earn 

one allowance for each qualifying vehicle sold. Manufacturers can use these allowances 

in MY 2017 through 2022 to help demonstrate compliance with the phase-in percentage 

requirements and fleet average evaporative emission standards for those years. Since 

credits and allowances serve primarily the same purpose and allowing for splits of 

allowances/credits greatly complicates program implementation, the final rule provides 

that manufacturers can only earn allowances in MYs 2015-2016 for any LDVs and 
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LDT1/2s meeting the Tier 3 evaporative emission regulations which are sold outside of 

California and the states that have adopted CARB’s ZEV or LEV III programs and for 

.MYs 2015-2017 for any qualifying LDT3/4, MDPV, and HDGV.354

Allowances will be used in the compliance determination in the following 

manner. Vehicles qualifying for allowances can be used in the fleet average evaporative 

emission standard calculation for any year during the phase-in. This applies to the 

primary phase-in and alternative phase-in programs. Allowance vehicles will be entered 

into the compliance calculation with an emission value equivalent to the evaporative 

emission standard for their vehicle category from Table IV-19 even if it was certified to 

CARB PZEV zero evap or LEV III Option 1 standards (Table IV-20). For the percent 

phase-in requirement in either the primary or alternative phase-in schemes, allowance 

vehicles will count for one vehicle for each allowance used within their vehicle category. 

For the primary scheme this will be counted as one vehicle, but for the alternative phasein option the value will be multiplied by the weighting factor (6 for 2017, 5 for 2018, 4 

for 2019, 3 for 2020, etc). Within the alternative phase-in scheme the manufacturer will 

be limited to using these early allowances for no more than 10 percentage points of the 

phase-in requirements in any given model year (e.g., MYs 2017-2022). EPA believes 

this limitation is appropriate since early use in the alternative phase-in scheme is 

multiplied and early introduction of “zero evap” technology should be encouraged, but 

not necessarily at the expense of its widespread use across the various vehicle categories 

as the phase-in progresses. The allowances are designed primarily to facilitate 

manufacturer transition during the program phase-in. As such, they may not be traded 

between manufacturers and unused allowances will expire after the 2022 MY. 

An example here may be helpful in demonstrating how allowances will work. 

Take a hypothetical manufacturer who earned a total of 10,000 allowances in MYs 2015 

and 2016 and sells 100,000 units per year. In MY 2018, the manufacturer will have a 

phase-in requirement of 60 percent or 60,000 vehicles. For the primary phase-in option 

the manufacturer could use part or all of its allowances in 2018 without restriction. For 

the alternative phase-in scheme assume the manufacturer set its alternative phase-in value 

at 60 percent for the 2018 MY. The final regulations limit the use of allowances to 10 

percentage points of the 60 percent or in this case 10,000 vehicles out of 60,000. Without 

a multiplier this will require the use of all 10,000 allowances in 2018, but with the 

multiplier of 5 for MY 2018 only 2,000 allowances are needed to reach the 10 percentage 

point maximum. Using a similar calculus, the manufacturer could use another 10 

percentage points in MY 2019, but it will require 2,500 allowances to reach this level 

since the multiplier is 4 assuming sales remain at 100,000 units per year. The number of 

allowances to reach the 10 percentage point level will increase each year as the multiplier 

decreases.

 

354 LDVs and LDT1/2 sold in California and states which have adopted the LEV III or ZEV programs 

cannot generate allowances because these programs will already require zero evap technology vehicles in 

those states in MYs 2015-2016. 
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d. Evaporative Emissions Averaging, Banking, and Trading

i. Introduction

Throughout EPA’s programs for mobile source emission controls, we have often 

included emission averaging programs for exhaust emissions. An emission averaging 

program is an important factor we take into consideration in setting emission standards 

under the Clean Air Act. An emission averaging program can reduce the cost and 

improve the technological feasibility of achieving standards, helping to ensure the 

standards achieve the greatest achievable reductions, considering cost and other relevant 

factors, in a time frame that is earlier than might otherwise be possible. Manufacturers 

gain flexibility in product planning and the opportunity for a more cost-effective 

introduction of product lines meeting a new standard. Emission averaging programs also 

create an incentive for the early introduction of new technology, which allows certain 

emission families to act as leaders for new technology. This can help provide valuable 

information to manufacturers on the technology before they apply the technology

throughout their product line. 

These programs generally involve averaging and banking, and sometimes trading 

(ABT). Averaging allows a manufacturer to certify one or more families at emission 

levels above the applicable emission standards as long as the increased emissions are 

offset by one or more families certified below the applicable standards. These are 

referred to as individual family emission limits (FELs). The over-complying families 

generate credits that are used by the under-complying families. Compliance is 

determined on a total mass emissions basis to account for differences in production 

volume, and on other factors as necessary such as useful life. The average of all 

emissions for a particular manufacturer’s production within a vehicle category must be at 

or below the level of the applicable emission standards. Banking allows a manufacturer 

to generate emission credits and bank them for future use in its own averaging program in 

later years. Trading allows a manufacturer to sell credits or obtain credits from another 

manufacturer.

EPA proposed and is finalizing an emissions ABT program for the Tier 3 hot soak 

plus diurnal evaporative emissions standards. The evaporative emissions ABT program 

is generally structured and operates the same as that for exhaust emissions as discussed in 

Section IV.A.7.m. The major difference is the added requirement to reconcile 

compliance with the fixed percentage requirement as discussed in detail in Section 

IV.C.2.a. Also, there is a five year credit life for evaporative emissions as opposed to the 

longer interim values for NMOG+NOx FTP and SFTP credits. 

This is the EPA’s first averaging type program for evaporative emissions from 

light-duty or heavy-duty vehicles. It does not apply to the canister bleed standard or the 

leak standard because it is the low altitude “zero evap” hot soak plus diurnal standard 

which will drive the fundamental approach used to comply with all of these requirements. 

We sought comment on the value of including trading in the program. The comments 
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from the Alliance of Automobile Manufacturers and the Association of Global 

Automakers very generally supported the inclusion of trading but provided no detail. 

Upon follow-up from EPA no manufacturer provided any further explanation on the need 

for the program or how they might use it.355 In past similar programs for exhaust 

emissions there have been only a few trades, but incorporating trading within the program 

adds a degree of flexibility if a manufacturer finds itself in a credit deficit situation. 

Thus, we have decided to include trading, but credit trades are limited based on the same 

averaging set restrictions as discussed below for averaging and banking. 

The evaporative emissions ABT program will start with the 2017 MY for the 

percentage and 20/20 options. Prior to the 2017 MY and for other options as discussed in 

Section IV.C.2.b, manufacturers may earn allowances. The programs will continue for 

the 2018 MY and beyond for all manufacturers regardless of their 2017 MY option and 

will not sunset, as does the allowance program. Vehicles generating ABT credits in the 

2017 MY or later will not be permitted to also generate allowances as this would be 

double counting.

A key element of an averaging program is the identification of the averaging sets. 

This establishes the basis within which evaporative emission families can be averaged for 

purposes of compliance as well as credit and deficit determinations. As proposed, we are 

finalizing four averaging sets and the applicable emission standard for each of the 

averaging sets as shown in Table IV-19. Except as noted in Section IV.C.2.d.2 below, 

credit exchanges between averaging sets will not be permitted. Participation in ABT is 

voluntary since a manufacturer could elect to certify each family within the averaging set 

to its individual standard as if there were no averaging program. 

An evaporative emission ABT calculation and assessment involves two distinct 

steps. The first is the determination of the credit/deficit status of each family relative to 

its applicable standard from Table IV-19. The second is the role of ABT calculations in 

the overall compliance demonstration which is discussed in Section IV.C.2.d.

ii. Family Emission Limits

A manufacturer choosing to participate in the evaporative emissions ABT 

program will certify each emission family to an FEL that applies for the hot soak plus 

diurnal standard for low altitude testing. The FEL selected by the manufacturer becomes 

the emission standard for that emission family. Emission credits (or deficits) are based 

on the difference between the emission standard that applies (by vehicle category) and 

the FEL. The vehicles will have to meet the FEL for all emission testing. As mentioned 

in Section IV.C.1.b., above, for vehicles certified with FELs above or below the 

 

355 See Alliance of Automobile Manufacturers and Association of Global Automakers comments on the 

NPRM (dated July 1, 2013) and Passavant, G. (June 2013 ) EPA and Auto Industry Meeting Related to Tier 

3 Evap and OBD NPRM. Memorandum to the docket.
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applicable standard for testing at low altitude, the same differential will apply to the FELs 

for high-altitude. This high-altitude FEL will not be used for any emission-credit 

calculations, but it will be used as the emission standard for compliance purposes. 

The final rule provides that the FELs selected by the manufacturer must be 

selected at 0.025 g/test increments above or below the applicable Tier 3 evaporative 

emission standards for each vehicle category. For example, for LDVs the increments for 

the FELs would be +/- 0.025 from 0.300 g/test (e.g., 0.225, 0.250, 0.275, 0,300, 0.325, 

0.350, 0.375 ... 0.500). The FEL is used in the compliance demonstration not the 

certified level. The certified level must be below the FEL, but the FEL could be a higher 

value than the closest increment value. For example, a certified value of 0.235 g/test 

could support an FEL of 0.250 g/test or any other higher increment value. One 

commenter asked that the gradation be finer than 0.025 g/test, but EPA believes this is 

the appropriate increment, since the standard itself is the sum of two values and rounding 

of the measured values is involved.

FELs are capped such that they cannot be set any higher than 0.500 g/test for 

LDVs, 0.650 g/test for LDT1s and LDT2s, 0.900 g/test for LDT3s and LDT4s, 1.000 

g/test for MDPVs, 1.4 g/test for HDGVs at or below 14,000 lbs GVWR, and 1.9 g/test for 

those above 14,000 lbs GVWR, respectively. These FEL caps are the 3-day hot soak plus 

diurnal emission standards applicable under EPA’s existing regulations. While we asked 

for input on these FEL caps and vehicle groupings, no party provided comment.

Total evaporative emission credits (or deficits) under the Tier 3 hot soak plus 

diurnal ABT program will be calculated differently in the 2017 model year and the 2018 

and later model years. For 2017 calculations will be based on sales in the U.S. excluding 

California and the section 177 states which have adopted the LEV III/ZEV programs. 

For 2018 and later model years it will be based on all 50 states. Calculations will use the 

following equation: Credits = (fleet average standard – fleet average FEL) × “U.S. 

sales”. The “fleet average standard” term here is the applicable Tier 3 hot soak plus 

diurnal standard for the vehicle category from Table IV-19. The sales number used in the 

2018 and later MY calculation will be the number of vehicles of the evaporative emission 

families in that category sold in the U.S. which are subject to the Tier 3 evaporative 

emission standards. Emission credits banked under the evaporative emission ABT 

program will have a five year credit life and will not be discounted. This means the 

credits will maintain their full value through the fifth model year after the model year in 

which they are generated. At the beginning of the sixth model year after they are 

generated, the credits will expire and cannot be used by the manufacturer. We are 

limiting credit life so there is a reasonable overlap between credit generating and credit 

using vehicles. As mentioned above, for purposes of the compliance calculation, 

allowance vehicles will have an FEL equivalent to the EPA emission standard (Table 

IV-19) for their respective vehicle category. 

iii.Compliance Demonstration
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Demonstration of compliance with the evaporative emissions standards is done 

after the end of each model year. There are two steps. In the first step, as discussed 

above, manufacturers must show compliance with the applicable phase-in percentages 

from the primary phase-in scheme (i.e., 40, 60, 80, and 100), the 20/20 option for MY 

2017, or an alternative phase-in percentage scheme. It is sales from these families 

together with their respective FELs which will be used to make the demonstration of 

compliance with the emission standard on average within each vehicle averaging set. 

Compliant vehicle types for these purposes are the same as described in Section IV.C.1.c 

above for projected sales. If the required sales percentages are not met by direct sales or 

allowances, non-Tier 3 vehicles would have to be identified to make up the shortfall in 

this calculation but would not be subject to the canister bleed or leak standard 

requirements.

 In the second step, using the FELs, manufacturers calculate the sales-weighted 

average emission levels within each of the four vehicle categories using sales for each 

family.

356

 Manufacturers are allowed to use credits only within a defined averaging set. 

The averaging sets are: (1) LDVs and LDT1s, (2) LDT2s, (3) LDT3s, LDT4s, and 

MDPVs, and (4) HDGVs. These sales-weighted calculated values must be at or below 

the emission standard for that vehicle category as shown in Table IV-19, (unless credits 

from ABT are used). If the difference between the standard and the sales-weighted 

average FEL is a positive value this could generate banked credit available for future use. 

If the difference between the standard and the sales-weighted average FEL is a negative 

value this would be a credit deficit which could be covered by previously banked credits. 

Credit deficits will be allowed to be carried forward through negative banking. However, 

manufacturers are required to make up any deficits within the three subsequent model 

years with credits from vehicles in the same averaging set, except as described below. 

That is, after calculations for the fourth model year are complete, all previous deficits 

from the preceding model years will have to be resolved by credits generated by the 

manufacturer or acquired through trading from vehicles within the same averaging set. 

As an illustration, a credit deficit accumulated in MY 2017 would have to be eliminated 

not later than the time that the 2020 MY ABT calculation is submitted to EPA. In no 

case will a manufacturer be permitted to carry a deficit (negative credit balance) for more 

than three consecutive model years. Using a similar illustration, all credit deficits 

accumulated in MYs 2017, 2018, and 2019 would have to be eliminated not later than the 

time that the 2020 MY ABT calculation is submitted to EPA. 

As discussed above, manufacturers are required to identify and include in the 

calculations for each of the four averaging sets, vehicle families from each of the vehicle 

categories (see Table IV-19) until the total annual nationwide sales in the given model 

year equals or exceeds the prescribed percentages. This could include non-Tier 3 

 

356 For MY 2017 calculations will be based on sales in the U.S. excluding California and the section 177 

states which have adopted the LEV III/ZEV programs. For 2018 and later model years it will be based on 

all 50 states.
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vehicles. If the inclusion of non-Tier 3 vehicles results in an exceedance of the hot soak 

plus diurnal emission standard for that category of vehicles, the credit deficit would have 

to be made up in a subsequent model year. Credits from banking and trading can be used 

to cover deficits at any time within the appropriate averaging set. 

Allowances can also be used to demonstrate compliance with the percentage 

phase-in requirements and the vehicle category average emission standard. For purposes 

of the percentage phase-in requirements, vehicles which have earned allowances are 

counted as compliant in the percentage calculation. For purposes of the calculations for 

compliance with the emission standard, allowance vehicles enter into the evaporative 

emissions compliance calculation as having an emission rate equivalent to the standard 

for that category of vehicle. Thus, allowance vehicles can help in demonstrating 

compliance with the percentage phase-in requirement (up to ten percentage points per 

model year in the alternative phase-in scheme) and can help in reducing deficits since 

their calculation value is equivalent to the level of the standard. 

 As presented in detail above, during the 2017-2021 MYs EPA is allowing 

manufacturers limited flexibility to meet the percentage phase-in requirements using 

carryover certification data from vehicles certified to CARB PZEV zero evap and CARB 

LEV III Option 1 standards in the 2015 or 2016 model years. These vehicles may have 

certification values slightly higher than those of EPA’s Tier 3 program for the given 

vehicle and vehicle category. Since the emission standard values in Table IV-19 and 

Table IV-20 are very similar for any given vehicle category, for purposes of 

simplification during the phase in, EPA in the final rule provides that any CARB PZEV 

zero evap or CARB LEV III Option 1 vehicles used in the 2017-2021MYs emission 

standard compliance determination be entered into the calculation with the emission level 

equivalent to the Tier 3 vehicle category in which the vehicle model would otherwise fit. 

However, we are not allowing manufacturers to generate emission credits for families 

certified with EPA based on carryover CARB PZEV zero evap or CARB LEV III Option 

1 evaporative emissions data as provided for in Table IV-20. We are not including these 

vehicles in the ABT program since the programs are not directly comparable, and the 

structure of the current CARB ZEV program, which is the genesis of most PZEV zero 

evap offerings, allows for a different number of PZEV sales as a function of 

manufacturer size and CARB LEV III Option 1 does not permit averaging. 

 As mentioned above, we are limiting use of credits to only within a defined 

averaging set. Cost effective technology is available to meet the hot soak plus diurnal 

emission standards on average within each of the vehicle categories in the averaging sets, 

especially since the standards are designed to accommodate nonfuel hydrocarbon 

background emissions. Thus, further flexibility is not needed. Moreover, we are 

constraining averaging to within these sets because of equity issues for the 

manufacturers. We are concerned that in the absence of such constraints the four or five 

manufacturers with a wide variety of product offerings in most or all of these categories 

would have a competitive advantage over the majority of manufacturers which have more 

limited product lines. This effect could be even more pronounced if the number of 
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evaporative families is considered, since larger more diverse manufacturers have more 

models and thus more evaporative families. 

Nonetheless, manufacturer use of credits from different averaging sets to 

demonstrate compliance is permitted in limited cases. As noted above, if a manufacturer 

has a credit deficit at the end of a model year in a given averaging set, they will have to 

use credits from the same averaging set during the next three model years to make up the 

deficit. However, if a deficit still exists at the end of the third year (i.e., the deficit has 

existed for three consecutive model years) , we are incorporating provisions to permit a 

manufacturer to use banked or traded credits from a different averaging set to cover the 

remaining deficit in the fourth model year’s ABT calculation, with the following 

limitations. Manufacturers are able to use credits from the LDV and LDT1 averaging set 

to address remaining deficits in the LDT2 averaging set, and vice versa. Furthermore, 

manufacturers are permitted to use credits from the LDT3, LDT4, and MDPV averaging 

set to address remaining deficits in the HDGV averaging set, and vice versa. No other 

use of credit exchanges across different averaging sets is allowed. These restrictions are 

being finalized because of equity concerns caused by the different nature and size of 

various manufacturer product lines. 

For both the percentage phase-in and sales-weighted average calculation steps 

above, we are basing the calculation on nationwide sales (excluding California and the 

section 177 states which have adopted the LEVIII/ZEV programs) in the 2017 MY since 

the anti-backsliding provisions of the LEV III evaporative emissions program are in place 

through the 2017 MY. The program uses annual nationwide sales beginning in the 2018 

MY. We believe this approach is consistent with the manufacturers’ plans for 50-state 

vehicles. A program design which enables a nationwide program has been an important 

premise of this rulemaking. Furthermore, this is simpler for the manufacturers and for 

EPA since it relieves the need to project future model year sales or track past model year 

sales at a disaggregated level. We recognize that decisions by the manufacturers on a 

national fleet versus a bifurcated approach such as exists today (California and the 

section 177 states which have adopted the LEVIII/ZEV programs separate from the rest 

of U.S. sales) may not yet have been made. The CARB LEV III and EPA phase-in 

requirements are identical beginning in 2018, so EPA sees little need for concern that a 

nationwide-based accounting approach could lead to disproportionate state by state 

impacts or the encouragement of practices which would lead to any particular state or 

area not receiving the anticipated emission reductions with this nationwide approach to 

the calculation. 

As discussed above, manufacturers not meeting the percentage phase-in 

requirements will need to include non-Tier 3 vehicles in the count and include their 

emissions in the overall calculation of compliance with the hot soak plus diurnal standard

and resolve shortfalls in compliance with the emission standard with future reductions, 

earned allowances, or credits. These non-Tier 3 vehicles would not be subject to leak 

standard or canister bleed standard requirements. The additional vehicles could only be 

meeting the Tier 2 hot soak plus diurnal requirements and adding these vehicle 
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families/vehicles into the calculation may result in a credit deficit. A manufacturer could 

not have an unresolved deficit for more than three model years as discussed below. The 

deficit would have to be eliminated with positive credits not later than the ABT 

calculation and credit reconciliation which occurs after the fourth model year.

Resolving this sales percentage shortfall problem becomes a bit more complicated 

for the 2017 MY 20/20 option because it requires that 20 percent of vehicles meet the 

Tier 3 evaporative emission requirements and that 20 percent meet the leak standard. 

These may or may not be the same vehicles. As a means to resolve this potential 

problem, EPA is requiring that any shortfall of either of the 20 percent values (Tier 3 

evaporative or leak standard) for the 2017 MY be covered by allowances or by future 

sales of vehicles meeting the Tier 3 evaporative emission requirements in excess of the

evaporative emission percentage sales requirement for that MY or some combination of 

MYs. For example, if a manufacturer was five percentage points short of either the 20 

percentage points for the hot soak plus diurnal or the 20 percentage points for the leak 

standard in the 2017 MY, then it will have to accelerate sales of vehicles meeting Tier 3 

evaporative emission requirements in the 2018-2021 MYs to cover the 5 percentage 

points (e.g., 65 percent in 2018 instead of 60 percent or 63 percent in 2018 MY and 62 

percent in the 2019 MY, etc.). These vehicles as Tier 3 vehicles in MY 2018 or later 

would also have to meet the leak standard.

e. Small Volume Manufacturers 

As flexibility, we are establishing provisions for small volume manufacturers and 

for those small business manufacturers and operationally independent small volume 

manufacturers with average annual nationwide sales of 5,000 units or less.357 These 

manufacturers would be permitted to delay meeting the Tier 3 evaporative emission 

standards, including the requirement to use EPA certification test fuel, until the 2022 

MY. See pages 29892 and 29998-29999 of the preamble to the NPRM and Section 

IV.G.5 below for a discussion of the 5,000 vehicle threshold. This includes the hot soak 

plus diurnal standards, the canister bleed emission standard, and the leak standard. In the 

interim, these vehicles must meet the existing evaporative and refueling emission 

standards. The initial determination of whether a manufacturer is under the 5,000 unit 

threshold will be based on the three year average of actual nationwide sales for MYs 

2012-2014. This allowance would not be affected if a qualifying manufacturer’s 

nationwide sales later exceed that value before 2022. Similarly, new market entrants (not 

in the market in the 2012 MY) with projected sales of less than 5,000 units could be 

covered by the small volume manufacturer provisions. However, in this case if actual 

running average nationwide sales exceed 5,000 units per year in any three consecutive 

model years they will have to meet the Tier 3 evaporative requirements in the third model 

year thereafter. For example, if a new market entrant in 2015 projects nationwide 

 

357 See 40 CFR§86.1838-01(d).
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production of 4,000 units per year and the average of actual values in 2015-2017 exceeds 

5,000 units per year they will have to meet Tier 3 evaporative requirements by the 2020 

MY.

3. Technological Feasibility

Evaporative/refueling emission control systems are an integral part of the overall 

vehicle engine and fuel system. EPA is establishing two revised and three new standards 

in this rule (2-/3-day hot soak plus diurnal standards, high altitude standards canister 

bleed standards, fuel rig SHED standard, leak standard) and a new test fuel which applies 

to these standards as well as the current running loss, refueling, and spit back emission 

standards. 

Hot soak plus diurnal emissions are fuel vapors which arise from the fuel system 

when it is parked immediately after operation (hot soak) and during daily ambient heating 

and cooling or by means of permeation when the vehicle is at rest. Control of hot soak 

plus diurnal emissions is primarily achieved by routing fuel vapors to a canister filled 

with activated carbon. These vapors are stored on the carbon and purged in the engine 

during vehicle operation. Hot soak plus diurnal emission rates vary with fuel vapor 

pressure, temperature, and fuel system design. Permeation emissions have been reduced 

by improving fuel tank and fuel line materials. Permeation emissions are sensitive to the 

gasoline ethanol content. While EPA has required ethanol in the fuel used for assessing 

evaporative system durability since 2004, Tier 3 is the first rule to require the 

certification test fuel for gasoline-fueled vehicles to include ethanol (E10). 

Canister bleed emissions are fuel vapors which diffuse from the canister vent as a 

result of the normal redistribution of vapors within the activated carbon while the vehicle 

is at rest. The emission rate depends on the tank volume, its fill quantity, the size and 

architecture of the canister and the characteristics of the carbon itself. While the biggest 

effect of this vapor redistribution is a uniform vapor concentration within the canister, it 

can also cause vapors to escape through the canister vent even without continued canister 

loading resulting from fuel tank heating. 

Vapor leaks in the vehicle fuel/evaporative system can arise from micro-cracks or 

other flaws in various fuel/evaporative system component structures or welds, problems 

with component installations, and more generally from connections between components 

and fuel lines and vapor lines. Control of leaks is especially important to achieving full 

useful life emission control system performance. 

In Tier 3, the emissions test fuel is changing from 9 RVP E0 to 9 RVP E10. EPA 

does not expect the change in emissions test fuel to affect refueling, spit back, or running 

loss compliance technology or strategies.

While these elements of the evaporative/refueling program are separate 

requirements for compliance purposes, the integrated nature of the design and operation 
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of the evaporative/ refueling control systems and the vehicle engine/fuel systems often 

leads to co-benefits when technology is added or upgraded. In some cases technology to 

meet one of the new or revised evaporative emission requirements will either help in 

efforts to meet other evaporative type requirements or enhance durability. For example, 

technology used to address the canister bleed standard will also reduce hot soak plus 

diurnal emissions and technology to meet the leak standard will reduce hot soak plus 

diurnal emissions and enhance durability.

Based on review of current certification data and the documentation in current 

professional literature, there is no doubt that the technology is available to meet the final 

evaporative emission standards described in this rule.358 There are at least 50 vehicle 

models which met the requirements in 2013.359 There are many technologies 

manufacturers can consider which will reduce emissions and enhance durability. 

Manufacturer compliance options and cost considerations are also addressed by the 

phase-in flexibilities and as the ABT program.

In the NPRM we described a variety of technology approaches and calibrations 

which manufacturers could use to meet the Tier 3 evaporative emission requirements. No 

comments were provided on the stringency of the standards, the technologies, the 

feasibility of the standards, or the costs of compliance. Nonetheless, we updated our 

technology analysis in light of new certification data and vehicle technology projections. 

As in the analysis supporting the NPRM, we identified technologies on the basis of their 

control effectiveness and cost to implement. Not every model will use every technology

described below. Rather we expect manufacturers to apply the technologies needed on 

any given model to meet the compliance target level. The technologies could be broadly 

grouped into two segments. The first are those expected to see widespread use based on 

their effectiveness and cost to implement. The second are those which are in relatively 

widespread use today, but could be optimized if necessary to achieve further reductions. 

In many cases the reductions available from this second group are relatively small and the 

costs are slightly higher than for the other strategies. The anticipated control technologies 

to comply with the hot soak plus diurnal, canister bleed/rig, and leak standards are 

described briefly below and are grouped in these two basic segments. A more detailed 

analysis for each vehicle category is found in Chapter 1 of the Regulatory Impact 

Analysis (RIA). 

a. Technologies expected to see widespread use:

Engine/fuel system conversion: As projected in our RIA for the 2017-2025 light-duty

GHG emissions final rule, EPA projects a significant movement from port fuel injection 

(PFI) engines to gasoline direct injection (GDI) engines. This ranges from 60-100 percent 

 

358 Passavant, G. (December 2013). Assessment of 2013 MY Evaporative Emission Results. Memorandum 

to the docket.

359 See Chapter 1 of the RIA for more detail.
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of products for all categories except gasoline-powered trucks over 14,000 lbs GVWR. 

This reduces air induction systems emissions by 90 percent.

Air Induction System (AIS) Scrubber: For vehicles/engine models not converted to GDI, 

EPA projects the use of an AIS scrubber as is now used on some PZEV models. These 

would reduce air induction system emissions by 85 percent. 

Canister honeycomb: This is a lower gasoline working capacity activated carbon device 

designed to load and purge very easily and quickly. This device reduces canister bleed 

emissions by 90 percent but also provides control for the hot soak plus diurnal test. 

Reduce leaks from connections and improve seals and o-rings: Vapor leaks from 

connections and the emission rates from these leaks is exacerbated if poor sealing 

techniques or low grade seal materials are use in connectors such as o-rings. Reducing 

connections in the fuel and evaporative systems and improving techniques and materials 

would reduce these emissions by 90 percent. This would reduce hot soak plus diurnal 

emissions, improve durability, and help to assure compliance with the leak standard.

Move parts into the fuel tank: Another means to reduce leak-related vapor emissions is to 

move fuel evaporative system parts which are external to the fuel tank to the inside. 

Emissions from these parts would be completely eliminated. This would reduce hot soak 

plus diurnal emissions, improve durability, and help to assure compliance with the leak 

standard.

OBD evaporative system leak monitoring: Beginning in the 2017 model year, the OBD 

system will need to be able to find, confirm, and signal a leak in the evaporative system 

of 0.020 inches cumulative diameter or greater. This is currently done on most vehicles 

less than 14,000 lbs GVWR as a result of the manufacturers’ response to meeting CARB 

requirements, but will be mandatory under EPA regulations. 

b. Technologies expected to be optimized if necessary to achieve further 

reductions:

In the NPRM, EPA discussed a number of other technologies with the 

demonstrated potential to further reduce evaporative emissions. These included: (1) 

upgrading the activated carbon canister and optimizing purge calibrations (especially for 

larger displacement engines), (2) upgrading fuel line materials to reduce permeation, (3) 

improving the fuel tank barrier layer to reduce permeation, (4) improving fuel tank 

manufacturing processes to reduce tank seam permeation emissions, (5) upgrading the 

fuel tank fill tube material to reduce permeation, and (6) improving the security of the fill 

tube connection to the fuel tank. While each of these approaches reduces evaporative 

emissions, they are to large degrees in use today. Thus their further application may be 

limited to specific situations. It is worth noting, that the use of these technologies has 

contributed to the relatively large compliance margins under the existing hot soak plus 

diurnal standards. 
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The reductions required and cost of compliance for any given vehicle model will 

depend on its current certification level and the type of evaporative emission control 

technology applied. The baseline emission values for 2-day hot soak plus diurnal 

evaporative emission certification for current models range from 0.42-0.96 grams per test 

(g/test). Achieving the desired compliance targets (at least 25 percent below the Tier 3 

standard) would require reductions ranging from 0.12 g/test for LDT2s to 0.51 g/test for 

HDGVs.360 EPA estimates 2025MY costs in the range of $9-15 per vehicle with a fuel 

cost savings of about $2 over the vehicle life. The application of the technologies 

expected to see widespread use under Tier 3 will create the margins need for compliance 

and in some cases create excess reductions which could be used to generate credits for 

ABT.

4. Heavy-Duty Gasoline Vehicle (HDGV) Requirements 

a. Background on HDGV

HDGVs are gasoline-powered vehicles with either a GVWR of greater than 8,500 

lbs, or a vehicle curb weight of more than 6,000 lbs, or a basic vehicle frontal area in 

excess of 45 square feet.361 HDGVs are predominantly but not exclusively commercial 

vehicles, mostly trucks and other work type vehicles built on a truck chassis. EPA often 

discusses HDGVs in three basic categories for regulatory purposes according to their 

GVWR class. These are Class 2b (8,501-10,000 lbs GVWR), Class 3 (10,001-14,000 lbs 

GVWR), and Class 4 and above (over 14,000 lbs GVWR). These are further subcategorized into complete and incomplete vehicles.362

 Class 2b HDGVs are mostly

produced by the manufacturers as complete vehicles and are very similar to lower 

GVWR LDTs of the same basic model sold by the manufacturers. Class 3 HDGVs are 

also built from LDT chassis with fuel system designs that are similar to their Class 2b and 

LDT counterparts, but these are on some occasions sent to secondary manufacturers as 

incomplete vehicles to attach a load carrying device or container. EPA estimates that 

more than 95 percent of Class 2b/3 vehicles are complete when they leave the original 

equipment manufacturer (OEM). Class 4 and above HDGVs are built on a more 

traditional heavy-truck chassis and in most cases leave the OEM as an incomplete 

vehicle. For Class 2b/3 vehicles, it is common to certify the vehicle for emissions 

purposes (exhaust, evaporative, etc) as a full chassis, while for Class 4 and above the 

 

360 Passavant, G. (December 2013). Assessment of 2013 MY Evaporative Emission Results. Memorandum 

to the docket.

361 MDPVs also meet the definition of HDVs, but they are classified separately for evaporative and 

refueling emission purposes. See 40 CFR 86.1803-01.

362 Heavy-duty vehicles may be complete or incomplete. A complete HDGV is one that has the primary 

load carrying device or container (or equivalent equipment) attached, normally by the vehicle OEM. An 

incomplete vehicle is one that does not have the primary load carrying device or container (or equivalent 

equipment) when it leaves control of the manufacturer of the engine. 
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vehicle is certified as a chassis for evaporative emissions while the engine is 

dynamometer certified for exhaust emissions.

HDGVs have been subject to evaporative emission standards since the mid 1980s. 

Recently, the timing of the standards has lagged requirements for LDVs and LDTs by 

several years, but the standards are of comparable stringency when vehicle size and fuel 

tank volume are considered. The most recent 2/3 day hot soak plus diurnal standards for 

HDGVs took effect in 2008. Refueling control requirements apply to complete Class 2b 

vehicles only. These requirements phased-in over the period from 2004-2006.

b. HDGV Evaporative Emission Control Requirements

As discussed above, EPA is including HDGVs within the Tier 3 evaporative 

emissions program. The hot soak plus diurnal and canister bleed test emission standards 

that will apply to these HDGVs are presented in Table IV-19 and-Table IV-20 and the 

high altitude standard is presented in Table IV-21. These vehicles will be included in the 

averaging calculation beginning in the 2018 MY and will be eligible for creating and 

using allowances and credits. 

Furthermore, for the reasons discussed below, EPA is requiring that all complete 

HDGVs regardless of their GVWR be required to meet the refueling emission standards 

and use the test procedures currently required for LDVs and LDTs and complete Class 2b 

vehicles. (See §86.1813-17). In their comments, manufacturers expressed concern about 

the amount of gasoline used in the development and certification of refueling emission 

control systems for HDGVs (due to the larger fuel tanks). To address this concern, EPA 

will permit manufacturers to certify using two separate processes for vehicles with tanks 

of 40 gallons or larger. The first will be the engineering evaluation of canister and purge 

data from lighter weight HDGVs certified in the SHED to show that similar or scaled-up 

systems on heavier HDGVs have the purge volume and canister working capacity to pass 

the refueling standard. This could include a comparison of control system design 

elements such as canister shape, canister internal architecture, total canister volume, and 

total gasoline working capacity as well as purge air volume over the Federal Test 

Procedure. This would be subject to the application of good engineering judgment. The 

second is application of the provisions of 40 CFR 86.153-98 (a) through (b)(1) on a 

bench set up for a tank of the appropriate volume in lieu of a vehicle test to show the 

efficacy of the fill neck seal. Such a test could be conducted in a conventional SHED. 

The ORVR requirement applies to complete Class 3 vehicles by the 2018MY and 

all other complete HDGVs by the 2022MY. EPA proposed these requirements for Class 

3 HDGVs and asked for comment on extending the requirements to all HDGVs. The 

manufacturers expressly commented that HDGV ORVR requirements should be limited 
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to complete HDGVs.363 There are only four manufacturers of HDGVs. Of these, three 

offer complete products in the Class 3 weight range and none offer complete products in 

the Class 4 and above weight range. As mentioned above, Class 3 vehicles have largely

the same vehicle chassis and fuel system configurations as Class 2b vehicles. The 

manufacturers of complete Class 2b vehicles indicated to the CARB and EPA that they

carry across their Class 2b fuel evaporative control system designs onto Class 3 and this 

includes the onboard refueling vapor recovery (ORVR) system used for control of 

refueling emissions. Thus, applying refueling emission controls to complete Class 3 

vehicles adds no cost and has little additional emission reduction benefit. However, it 

does set a requirement to continue these controls in future model years. There are no 

complete Class 4 and above HDGVs and neither manufacturer who certifies incomplete 

HDGVs above 14,000 lbs GVWR objected to establishing an ORVR requirement for 

complete HDGVs.364 This sector is made of incomplete HDGV chassis and dieselpowered products. However, setting a requirement for potential future Class 4 and above 

designs establishes certainty for manufacturers but brings no near term cost burden or 

emission reductions. 

Incomplete HDGVs make up 15-20 percent of all HDGV sales. Of this, 

approximately 80 percent are Class 2b/3 and 20 percent are Class 4 and above. EPA is 

not extending the refueling emission control requirement to incomplete HDGVs at this 

time. The control system designs would be essentially the same as on complete HDGVs, 

but manufacturers have indicated to EPA that they would have to establish additional 

measures to ensure that the steps taken to complete the vehicle by the secondary

manufacturer do not compromise the integrity and safety of the fuel/evaporative control 

system (including ORVR) and that the ORVR system continues to perform properly with 

regard to emissions control. While there are relatively few of these vehicles, their 

contributions to the inventory are larger than might be expected due to their lower fuel 

economy. Given these contributions, EPA may consider proposing to apply ORVR to 

incomplete HDGVs in a future action. 

EPA is also including a provision that manufacturers be permitted to comply with 

the refueling emission standard as early as the 2015 MY to earn on a one-to-one basis 

allowances which could be used to phase-in the Class 3 refueling emission control 

requirement or as an allowance on a 2:1 basis under the Tier 3 evaporative emission 

program. EPA believes this is appropriate since the expected daily average reduction in 

vehicle refueling emissions for this class of vehicles is large relative to the reduction in 

evaporative emissions expected under Tier 3. This would also apply to any incomplete 

HDGV a manufacturer voluntarily certified to the refueling emission standards. Any

 

363 See comments of Alliance of Automobile Manufacturers and Association of Global Automakers in the 

public docket at EPA-HQ-OAR-2011-0135-4451. 

364 Passavant, G., (September 2013). EPA and General Motors Meeting on Issues Related to Tier 3 NPRM 

and (September 2013). EPA and Ford Meeting on Issues Related to Tier 3 NPRM. Memorandums to the 

docket.
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certifications, including those done early, must use EPA Tier 3 test procedures and 

certification test fuels or CARB LEV III equivalents.

c. Other Program Elements for HDGVs 

In the NPRM, EPA sought comment on several provisions related to Tier 3 

certification test fuel and evaporative emission control requirements. 

First, EPA sought comment on whether heavy-duty gasoline engines (HDGEs) 

not subject to new Tier 3 exhaust emission standards (those certified for exhaust 

emissions using an engine dynamometer) which are used in HDGVs subject to Tier 3 

evaporative emission standards should certify for exhaust emissions on Tier 3 emissions 

test fuel.365 Manufacturers responded by asking that the use of Tier 3 fuel for HDGE 

exhaust emissions certification be voluntary, but agreed that the use of Tier 3 certification 

fuel would not change the stringency of the current dynamometer-based emission 

standards or the costs of compliance. Based on consultations with manufacturers, EPA 

has decided to require that all HDGEs be certified on Tier 3 fuel by the 2022MY.366 To 

provide flexibility for very unique applications or circumstances, EPA will allow up to 

five percent of a manufacturer’s dynamometer-certified HDGE sales in any given model 

year to be certified using Tier 2 certification fuel. This flexibility is limited to 

certification based on carryover data beginning in the 2022MY. 

Second, as discussed in Section IV.F.5 for light-duty vehicles, we are committed 

to the principle of ensuring that any change in test fuel for heavy-duty gasoline 

vehicles/engines will not affect the stringency of either the fuel consumption or GHG 

emissions standards. As part of the separate rulemaking discussed in Section IV.F.5, we 

expect to establish the appropriate test procedure adjustment for HD engine fuel 

consumption standards and to determine the need for any test procedure adjustment for 

GHG emissions standards based on the change in certification test fuels. 

Third, to simplify the evaporative emission regulations for HDGVs and to bring 

them more in line with the current structure of the product offerings in this sector, we are 

finalizing provisions to permit evaporative emissions certification by engineering 

analysis for vehicles above 14,000 lbs GVWR (instead of above 26,000 lbs GVWR as 

permitted in the existing regulations). We are also finalizing regulatory language to 

clarify how these provisions are to be implemented. This applies to the hot soak plus 

 

365 EPA also sought comment on whether to require HDGVs to use Tier 3 emissions test fuel for 

evaporative emissions standards even if we did not adopt the proposed Tier 3 evaporative emission 

standards and whether to allow Class 4 and above HDGVs to earn allowances or credits if EPA did not 

adopt the Tier 3 standards for these vehicles. These have been superseded by our decision to apply the Tier 

3 evaporative emission standards to all HDGVs as described above. 

366 Passavant, G. (September 2013). EPA and General Motors Meeting on Issues Related to Tier 3 NPRM 

and (September 2013). EPA and Ford Meeting on Issues Related to Tier 3 NPRM. Memorandums to the 

docket.
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diurnal, running loss, and canister bleed standards. These HDGVs will remain subject to 

the emission standards when tested using the specified procedures. This is the same cut 

point allowed by CARB and will allow for one certification method. Even though it was 

supported by one commenter, we are not including specific provisions for design-based 

certification for HDGVs over 14,000 lbs GVWR. EPA believes that the option to certify

using engineering analysis and data serves the same purpose.

Fourth, we are finalizing a revised description of evaporative emission families 

that does not reference sealing methods for carburetors or air cleaners as this technology

is now obsolete for HDGEs.

Fifth, EPA is finalizing regulatory language permitting HDGVs over 14,000 lbs 

GVWR to be grouped with those between 10,001 and 14,000 lbs GVWR for purposes of 

complying with evaporative and refueling emission control standards and related 

provisions. In these cases, we require these HDGVs to meet all the requirements 

applicable to the group in which they are being included (e.g., useful life, OBD, etc.).

Finally, the regulations at 40 CFR part 86, subpart M, describe how to test heavyduty vehicles above 14,000 lbs GVWR to demonstrate compliance with evaporative 

emission standards. Most of these provisions are identical to those that apply under 40 

CFR part 86, subpart B. We are eliminating subpart M and replacing it with a simple 

instruction to test these heavy-duty vehicles using the procedures of subpart B, with a 

small number of appropriate modifications noted as exceptions to the light-duty test 

procedures. Relying on references to subpart B instead of largely copying them into 

subpart M eliminates many pages of unnecessary regulatory text and makes it easier to 

maintain a consistent set of requirements. Changing a provision in subpart B in the future 

will automatically apply for evaporative testing of both light-duty and heavy-duty 

vehicles unless otherwise provided in the particular rulemaking. 

In response to comments received, we are specifying that heavy-duty vehicles 

above 14,000 lbs GVWR must use the same drive schedules and test fuels that apply for 

light-duty vehicles. Subpart M already allows light-duty drive schedules and certification 

test fuels as an alternative to using those for heavy-duty vehicles, and most if not all 

manufacturers of these vehicles already use the light-duty drive schedules, which 

facilitates testing simplicity and coordination of design parameters with light-duty

vehicles. The heavy-duty drive schedule generally involves less driving, which makes 

this the more stringent test option for designing purge. Omitting this more stringent 

option therefore does not change the effective stringency of the applicable standards. 

With these changes from the proposed rule, there are only two aspects of testing 

that are different for heavy-duty vehicles above 14,000 lbs GVWR. First, the regulations 

specify that the exhaust emission measurements are not required for the driving portion 

of the test between canister pre-conditioning and diurnal testing. Exhaust emission 

standards in this vehicle size range apply based on engine testing only. Second, wider 

engine speed tolerances apply. This is captured in part 1066 by specifying wider engine 
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speed tolerances for any testing that does not require exhaust emission measurements 

since the greater allowance has no effect on emissions measurements. This applies, for 

example, for pre-conditioning drives for light-duty vehicles, and it also applies for preconditioning related to evaporative emissions of heavy-duty vehicles above 14,000 lbs 

GVWR. 

There are some differences in the existing test provisions in subparts B and M that 

we are not preserving. Some of these differences arose from changes to subpart B that 

were inadvertently not carried over to subpart M. In other cases, there may have been an 

intentional distinction that no longer applies (such as provisions related to slippage on 

twin-roll dynamometers). Also, we are not retaining distinctions in Subpart M related to 

procedures for determining road load settings and for operating manual or automatic 

transmissions. Additional differences we are not preserving include gas divider 

specifications, SHED and dynamometer calibration procedures, and some provisions for 

alternative canister loading and vehicle pre-conditioning. We are also restoring the 

content of §86.1235(b) through (i) related to dynamometer operating procedures, which 

were inadvertently removed in an earlier rulemaking. 

5. Evaporative Emission Requirements for FFVs

A flexible fuel vehicle (FFV) as defined in 40 CFR 86.1301-01 means any motor 

vehicle engineered and designed to be operated on a petroleum fuel and on a methanol or 

ethanol fuel or any mixture of the petroleum fuel and methanol or ethanol. Many 

manufacturers have one or more FFVs in their product offerings. These include many

different LDV and LDT vehicle chassis styles including passenger cars, mini-vans, pickups, sport utility vehicles and even a few HDGVs.

The EPA regulations implementing the FFV provisions for ethanol FFVs, 

including those in 40 CFR 86.1811-04 and 86.1811-09, have been applied primarily for 

FFVs capable of operating on gasoline/ethanol mixtures up to E85. As a matter of 

policy, EPA has not required certification testing for evaporative and refueling emissions 

on the full range of E0-E85 fuel blends, but instead has allowed the option to use a blend 

created when Tier 2 fuel (9 RVP E0) is splash blended with ethanol to a 10 percent 

gasoline/ethanol blend. This simulates what often occurs in the vehicle fuel tank when 

Tier 2 fuel (9 RVP E0) is dispensed into a tank containing mostly E85. This yields a 

blend which has a Reid vapor pressure of about 10 psi. Nearly all manufacturers have 

certified using this option. The California ARB LEV III program has no special 

evaporative or refueling emission test fuel requirements for FFVs. 

In the Tier 3 NPRM, EPA proposed to revise the certification test fuel for 

evaporative emissions, to revise the hot soak plus diurnal emission standard, and to add a 

canister bleed emission standard and a leak standard. These standards apply to FFVs and 

non-FFVs. EPA proposed to revise the ethanol content of the certification test fuel for 

refueling emissions but did not otherwise propose to change the fuel vapor pressure, the 

level of the refueling emission standard or the test procedure. Furthermore, in the 
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NPRM, EPA sought comment on leaving unchanged the basic approach to FFV 

certification test fuel for Tier 3 evaporative and refueling emissions, except that the 

certification test fuel would be 9 RVP E0 splash blended with E15 such that the blend 

would have a 10 psi vapor pressure, i.e., the RVP of the evaporative emissions test fuel 

used by nearly all manufacturers. Manufacturers commented that the Tier 3 certification 

test fuel should be the same for FFVs and non-FFVs and that carryover should be 

permitted from Tier 2 to Tier 3. EPA met with several manufacturers to clarify their 

comments and to discuss issues affecting the evaporative and refueling emissions 

certification fuel for FFVs.367

For FFVs, EPA has several factors to consider for evaporative and refueling 

emission certification test fuel. First, EPA is finalizing a 9 RVP E10 certification test 

fuel for non-FFVs for evaporative and refueling emissions. This is consistent with our 

broader policy objective to allow the manufacturers to sell the same vehicles in all 50 

states. Second, 10 psi RVP certification test fuel for the Tier 3 evaporative emission 

standards for FFVs could result in more evaporative emission reductions than a 9 psi 

RVP test fuel, but this would be counter to the broader policy objective regarding a 

national program since CARB has no separate FFV evaporative emission standards and 

likely would affect the stringency of the final evaporative emission standards. 

Specifically, finalizing 10 psi RVP certification test fuel for the Tier 3 evaporative 

emission standards as applied to FFVs would increase the stringency of the evaporative 

emission standards for FFVs both compared to the Tier 3 evaporative emission standards 

with 9 psi RVP test fuel for non-FFVs and compared to the Tier 2/MSAT evaporative 

emission standards with 10 psi RVP test fuel for FFVs. Third, we are not changing the 

level of the refueling emission standard (though we are adding ethanol to the test fuel and 

extending ORVR to complete Class 3 HDGVs) and we did not examine how a potential 

change from the existing 10 psi RVP test fuel for FFV refueling would affect in-use 

emission reductions or the stringency of the refueling standard for FFVs. A change in the 

test fuel vapor pressure likely would likely lead to a change in the stringency of the 

refueling emission standard as they are now applied to FFVs. Retaining the current 

requirements for refueling emissions for FFVs does not affect the national program since 

CARB currently follows Federal Test Procedures and test fuels for ORVR. 

Balancing all of these factors, EPA is adopting a bifurcated scheme for 

evaporative and refueling emission certification for Tier 3. Evaporative emission 

requirements for the hot soak plus diurnal, canister bleed, running loss, spit back, and 

leak standards will be based on Tier 3 certification fuel (9 RVP E10) for FFVs. This will 

permit reciprocity between the LEVIII and Tier 3 evaporative emission standards 

programs and subject the manufacturers to only one set of evaporative emission tests for 

FFVs and non-FFVs. However, for the refueling emission standard, EPA is retaining the 

 

367 Passavant, G. (September, 2013). EPA, GM, Ford, and Chrysler Meeting on Tier 3 Certification Fuel for 

Evaporative and Refueling Emission Standards for FFVs. Memorandum to the docket.
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10 psi certification test fuel requirement for FFVs because the worst case in-use RVP 

conditions when E0 and E85 are commingled will still be possible. In current systems, 

the fuel vapor pressure in the refueling emission test drives the total gasoline working 

capacity of the activated carbon canister that is necessary in the integrated 

evaporative/refueling control system. Although a 10 psi RVP certification fuel for 

evaporative emissions control could be viewed as more stringent, we believe that keeping 

the fuel vapor pressure at 10 psi in the refueling test, which is what was proposed for 

comment, will help to assure that the in-use emission reduction benefits of current 

evaporative systems on FFVs are retained. We expect that total canister gasoline 

working capacities will still be driven by the 10 psi RVP fuel used in the refueling test 

and therefore the higher in-use RVP conditions which impact evaporative emissions will 

still be addressed. 

EPA is specifying a 10 RVP E10 test fuel specification for FFV refueling 

emissions certification. However, as a compliance alternative EPA will continue to 

permit certification based on in vehicle fuel tank blending of two different fuels (i.e., 

vehicle fuel tank filled to 10 percent of capacity with E85 and then refueled to at least 95 

percent of capacity with (9 RVP E0). Either of these approaches will also meet CARB 

certification test fuel requirements as the test fuel vapor pressure would be higher than 

with EPA’s 9 RVP E10 or CARB’s 7 RVP E10 test fuel. In addition, we are not 

changing existing requirements that all IUVP testing for evaporative and refueling tests 

are done on the non-FFV fuel (i.e., Tier 2 IUVP vehicles are tested on 9 RVP E0 and Tier 

3 IUVP vehicles are tested on 9 RVP E10.

In their comments on the Tier 3 NPRM, manufacturers asked that EPA allow 

carryover of certification emission data from Tier 2 to Tier 3. Since the regulatory

approach for refueling emissions is basically the same as what is currently being used by 

the manufacturers, we believe there should be opportunity for carryover of refueling 

emission data under the current regulatory program. Manufacturers also expressed 

concern that the refueling emission standard would require them to keep a 10 RVP E10 

or 9 RVP E0 test fuel solely for refueling emission standard certification purposes. To 

help address this concern, in certification testing, EPA would consider approving other 

refueling test fuel blends with 10 percent ethanol and 10 psi such as a refueling event 

where a tank is filled initially with 10 percent E85 and during refueling test is filled with 

90 percent 9 RVP E0. EPA would also permit manufacturers the option to seek EPA 

approval to certify by attestation using alternative procedures or through engineering 

analysis based on similar evaporative/refueling emission system configurations and 

emission test results and data on similar vehicles showing that the vehicle could pass the 

refueling emission standard and meet the requirements in use on 10 psi RVP E10 fuel. 

They would remain subject to confirmatory testing on 10 RVP E10. Both of these 

options could only be implemented with approval of the Administrator. 
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6. Test Procedures and Certification Test Fuel 

a. Review and Update of Testing Requirements

EPA adopted the current test requirements for controlling evaporative emissions 

in 1993.368 Those changes included: (1) diurnal testing based on heating and cooling the 

ambient air in the SHED369 instead of forcing fuel temperatures through a specified 

temperature excursion; (2) repeated 24-hour diurnal measurements to capture both 

permeation and diurnal emissions; (3) high-temperature hot soak testing; (4) hightemperature running-loss measurements with a separate standard, including controlled 

fuel temperatures according to a fuel-temperature profile developed for the vehicle; and 

(5) canister preconditioning to ensure that vehicles could effectively create canister 

capacity to prepare for several days of non-driving.

These test procedures are generally referred to as “enhanced evap” testing. EPA 

adopted these “enhanced evap” test procedures in coordination with CARB. The test 

requirements include two separate test sequences to demonstrate the effectiveness of 

evaporative emission controls. The “2-day sequence” involves canister loading to twogram breakthrough, followed by driving for the exhaust test (about 31 minutes), a hot 

soak test, and two days of cycled ambient temperatures. The “3-day sequence” involves 

canister loading with 50 percent more vapor than needed to reach breakthrough, followed 

by driving for the exhaust test, driving for the running loss test (about 97 minutes total), a 

high-temperature hot-soak test, and three days of cycled ambient temperature.

The 2-day sequence was intended primarily to insure a purge strategy which 

would create enough canister capacity to capture two days of diurnal emissions after 

limited driving. The two-day measurement period is also effective for requiring control 

of permeation and other fugitive emissions. The 3-day sequence was intended to 

establish a design benchmark for achieving adequate canister storage capacity to allow 

for several days of parking on hot summer days, in addition to requiring vehicle designs 

that prevent emissions during high-temperature driving and shutdown conditions. 

After adopting these evaporative test procedures, we set new standards for 

refueling emissions control which called for onboard refueling vapor recovery

(ORVR).370 Manufacturers have typically designed their ORVR systems to be integrated 

with their evaporative controls, using a single canister and purge strategy to manage all 

fuel vapors vented from the fuel tank. Due to the magnitude of the refueling emission 

load and the manner in which the load rates affect activated carbon capture efficiency, it 

 

368 58 FR 16002 (March 24, 1993).

369 SHED is the Federal Register acronym for sealed housing for evaporative determination. The SHED is 

the enclosure in which the evaporative emissions are captured before measurement.

370 59 FR 16262 (April 6, 1994). 
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has become clear that ORVR testing with these integrated systems serves as the 

benchmark for achieving adequate canister storage capacity. 

In the nearly 20 years since adopting these test procedures, manufacturers have 

made great strides in developing designs and technologies to manage canister loading and 

purging and to reduce permeation emissions. Except as discussed below, we are not 

changing the test procedures for demonstrating compliance with the Tier 3 emission 

standards. As described above, we are adopting a new standard based on measured values 

over a canister bleed test, and a fuel system rig test. These are intended to measure only 

fuel vapors which diffuse from the evaporative canister or permeate/leak from a fuel 

system. CARB developed these procedures as a means for setting standards that are not 

affected by nonfuel background emissions. The canister bleed test procedure is a 

variation of the established two-day test sequence. The canister is preconditioned by

purging and loading to breakthrough, then attached to an appropriate test vehicle for 

driving over the duty cycle for the exhaust test. The canister is then attached to a fuel 

tank for measurement. After a stabilization period, the tank and canister undergo two 

days of temperature cycling. Canister emissions are measured using a flame ionization 

detector (FID), with a conventional SHED approach or by collecting emissions in a bag 

and measuring the mass. Rather than repeating CARB’s regulations, we are 

incorporating those regulations by reference into the CFR.371 This will avoid the 

possibility of complications related to minor differences that may occur with separate test 

procedures. The fuel system rig test is a bench test where a complete vehicle fuel system 

(without the vehicle chassis) is constructed in the SHED and evaluated over the 3-day

cycle in both a “wet” and “dry” state.372

CARB adopted the fuel system “rig test” as an optional approach to demonstrate 

control of evaporative emissions without the effects of the nonfuel hydrocarbon 

emissions that are seen in testing the whole vehicle in the SHED. We generally expect 

manufacturers to comply with the EPA requirements which include the canister bleed test 

and emission standard instead of CARB LEV III Option 1 which includes the rig test and 

emission standard. However, since we are accepting PZEV zero evap and CARB LEV 

III Option 1 certifications for the 2017-2018MYs and 2017-2021 MYs, respectively, we 

are also incorporating by reference CARB’s rig test into the CFR to accommodate those 

manufacturers that do in fact rely on this approach.

 

371 For a description of the canister bleed test procedure (BETP), see pp.III-51 to III-55 of 

http://www.arb.ca.gov/db/search/search_result.htm?cx=006180681887686055858%3Abew1c4wl8hc&cof=

FORID%3A11&q=BETP&siteurl=http%3A%2F%2Fwww.arb.ca.gov%2Fhomepage.htm (last accessed on 

January 13, 2014).

372 See http:www.arb.ca.gov/msprog/macs/mac0503/mac0503.pdf for a description of the rig test standard 

and test procedure (last accessed on January 13, 2014).
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Also, as discussed further below, we are adopting a new leak test procedure which 

will be used to measure leak rates for the leak standard. The leak test standard test 

procedure is contained in the regulatory text. 

Manufacturers have raised a pair of related concerns regarding the current test 

procedures. First, hybrid vehicles and new engine designs for meeting fuel economy 

standards and CO2 emission standards increase the challenge of maintaining an adequate 

purge volume to prepare vehicles for the diurnal test. For hybrid vehicles this is related 

to the amount of time the engine is running. For other technologies this is related to the 

trend toward decreasing available vacuum in the intake manifold, which is the principal 

means of drawing purge air through the canister. Second, preconditioning the canister by 

loading to breakthrough serves as a disincentive for some control strategies that might 

otherwise be effective at reducing emissions, such as designs involving greater canister 

capacity or better containment of fuel vapors inside the fuel tank. In addition, we have 

learned from studying in-use emissions and in-use driving behaviors and usage patterns 

that it is not uncommon for vehicles to go for an extended period with little or no 

opportunity to purge the canister.

In the NPRM, we requested comment on an optional adjustment to the test 

procedure intended to address these three concerns. In this alternative, for designs 

involving pressurized tanks, manufacturers would determine an alternative vapor load to 

precondition the canister before the exhaust test. If, for example, a fuel system is 

designed to stay sealed up to 1 psi and to vent vapors to the canister if rising temperatures 

trigger a pressure-relief valve, the manufacturer could quantify the actual vapor load to 

the canister during three consecutive days of cycling through diurnal test temperatures. 

This three-day vapor load would be the amount of fuel vapor used to precondition the 

canister (loaded at the established rate of 15 grams per hour). This canister loading may

also involve butane instead of fuel vapor, but we would likely require a greater mass of 

butane to account for the fact that it is easier to remove the butane from the activated 

carbon in the canister. This approach would be flexible to accommodate any design 

target for pressurizing fuel tanks. Canister preconditioning for the ORVR test (for 

integrated and nonintegrated systems) would remain unchanged. EPA sees merit in 

further consideration of such test procedure flexibilities, but auto manufacturers did not 

provide support these concepts in their comments and we are not adopting the proposed 

optional adjustment. 

b. Test Fuel for Certification

EPA is changing the certification test fuel specifications as described in Section 

IV.F. Here we discuss some implications for evaporative and refueling emissions testing 

beyond those discussed above for FFVs. We are revising the certification test fuel 

specification in conjunction with the Tier 3 standards, principally to include ethanol and 

reduce sulfur such that the test fuel better aligns with the current and projected in-use 

fuel. Although we received unsolicited comment asking that we set durability test fuel 

specifications for evaporative and refueling emission control systems to be the same as 
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those for the certification test fuel (9 RVP E10 in this final rule), we are not changing 

durability fuel specifications in this rule other than to remove minimum sulfur content 

requirements. In particular, we are not changing the existing requirement that “any

mileage accumulation method for evaporative emissions must employ gasoline fuel for 

the entire mileage accumulation period which contains ethanol in, at least, the highest 

concentration permissible in gasoline under federal law and that is commercially

available in any state in the United States”. See §§ 86.1824-08(f)(1) and 86.113-

04(a)(3)(i). EPA believes this is prudent policy to ensure that emission control systems 

are designed for the fuels with the potential to adversely affect durability and there is no 

reason to change the existing approach especially since E15 fuel is now legally

permissible and commercially available for appropriate vehicles and there is potential for 

its market penetration to increase in the future. Any bench aging using E15 fuel must 

simulate the effects of alcohol in-use fuels on evaporative emission system components. 

Since there are already vehicles in the market which employ the technology 

needed to meet the new hot soak plus diurnal requirements, EPA is taking a flexible 

approach to the phase-in of the certification test fuel. This is summarized in Table IV-22. 

To accommodate vehicles already designed to meet CARB PZEV zero evap 

evaporative emission requirements, EPA’s phase-in provides that PZEV zero evap 

vehicles which qualify for carryover can use CARB Phase 2 fuel for evaporative 

emissions (hot soak plus diurnal and running loss standards) and rig test certification for 

MYs 2015-2019. For CARB PZEV zero evap vehicles, high altitude, refueling, and spit 

back standard certification may use either EPA Tier 2 or Tier 3 fuel in MYs 2015-2019. 

For the leak standard in the 2018 and later MYs, they must use Tier 3 test fuel. 

Beginning in the 2017 MY, the use of PZEV zero evap data is limited to carryover of 

data from 2015 or 2016 MY certifications. 

Those using CARB LEVIII Option 1 can use CARB Phase 3 fuel for evaporative 

emissions (hot soak plus diurnal and running loss standards) and rig test certification for 

MYs 2015-2021. For CARB Option 1, high altitude, refueling, and spit back standard 

certification must may use Tier 2 or Tier 3 fuel in MYs 2015-2016 but in the 2017 and 

later MYs all LEV III option 1 certifications for the high altitude, refueling, spit back, 

and leak standards must use EPA Tier 3 fuel. 

CARB LEV III Option 2 evaporative emission vehicles may use CARB Phase 3 

fuel to meet evaporative (hot soak plus diurnal and running loss standards) and canister 

bleed standards beginning in 2015MY and following. High altitude, refueling, and spit 

back may use Tier 2 or Tier 3 fuel in model years 2015 and 2016. For 2017 and later 

model years CARB LEV III option 2 evaporative families must use Tier 3 test fuel for 

high altitude, refueling, spit back, and leak standard certifications. 

Tier 3 evaporative emission vehicles must use Tier 3 fuel to meet evaporative 

emission (hot soak plus diurnal and running loss standards), high altitude, canister bleed, 

and refueling/spit back emission standards beginning in the 2015MY and following. 
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Beginning in the 2018 MY, Tier 3 vehicles must use Tier 3 emission test fuel to 

demonstrate compliance with the leak standard requirements.373

When the program is fully phased-in, any Tier 3 evaporative emission 

certification will have to use Tier 3 certification test fuel and test procedures or CARB 

equivalent test procedures and fuels. This could be done as early as the 2015 MY and 

will be required for all vehicle models by the 2022 MY.374 As indicated above and in 

Table IV-22, we are further applying the new test fuel at the same time to ORVR testing. 

Therefore, beginning in the 2017 MY if manufacturers do any new testing to demonstrate 

compliance with the Tier 3 evaporative emission standards (using Tier 3 or LEV III fuel), 

they will need to submit test data to demonstrate compliance with the refueling emission 

standards using the new certification test fuel as well as the leak (when applicable), spit 

back, canister bleed, running loss, and high altitude emission standards. Any family that 

is not yet captured within the Tier 3 phase-in percentage may remain on Tier 2 

certification fuel through the 2021 MY. By the 2022 MY all evaporative and refueling 

emission certifications will have to be on EPA test procedures and certification fuels or 

CARB equivalents as identified in the regulations. Policies regarding test procedures and 

test fuels for EPA confirmatory and other post certification testing are discussed in 

Section IV.C.6.e below. 

Finally, we are including provisions to allow any vehicle certified to the refueling 

spit back standard separately (mostly incomplete HDGVs)to continue to do so using Tier 

2 current certification fuel until the 2022 MY even if its evaporative emissions are 

certified on Tier 3 certification fuel. This is reasonable since the fill quality of the vehicle 

and eliminating spit back are not necessarily related to the ethanol or sulfur content of the 

gasoline. The manufacturers must meet this requirement through testing, as the 

engineering evaluation flexibility available for HDGVs over 14,000 lbs GVWR does not 

apply to this standard.

c. Correction for Ethanol Portion of the SHED Measurement

Another issue related to adding ethanol to the certification test fuel relates to the 

emission measurement in the SHED. Emissions are detected by flame ionization 

detectors (FID), which are less responsive to ethanol than gasoline. This effect causes 

under-reporting from the ethanol portion of the fuel vapor. Fuel-related emissions from 

the vehicle may be slightly more weighted toward ethanol than gasoline, depending on 

how the different fuel constituents permeate through various fuel-system materials, how 

they evaporate from the bulk fuel in the tank at varying temperatures, and how they

 

373 This provision applies in 2017 MY for vehicles meeting the Tier 3 requirements using the 20/20 option 

and does not apply to HDGVs with a GVWR greater than 14,000 lbs. Incomplete HDGVs have until the 

2022 MY to meet the spit back standard. 

374 The only exception here would be if a vehicle uses allowances in the 2022 model year to meet the Tier 3 

evaporative emission requirements.
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adsorb onto and desorb from the activated carbon in the canister. We proposed to address 

this issue by the use of a prescribed correction factor. Under this approach manufacturers 

would simply multiply their SHED measurement results by a fixed value to adjust 

upward for the difference in the FID response to ethanol. Data available to EPA at the 

time of the NPRM suggested that a value of approximately 1.1 would be appropriate for 

E15.375 For an E10 certification fuel, California ARB finalized a value of 1.08. 

In their comments, the manufacturers supported the use of a correction factor, but 

stipulated that the value put forth by EPA was too large and they should be given the 

option to measure the ethanol fraction of the vapor in the SHED through procedures and 

instrumental approaches prescribed in the regulations (see 40 CFR1065.269, 1065.369, 

and 1065.805) instead of using a fixed correction value. Two manufacturers provided 

data based on testing with E10 test fuel which generally showed lower ethanol fractions 

than represented by the 1.1 value proposed by EPA for hot soak plus diurnal emissions, 

and uniformly showed very low ethanol fractions for refueling measurements.376

EPA has reviewed the data provided by the manufacturers and has considered 

their comment that they should be given the option to measure the ethanol fraction and 

adjust the SHED results rather than be required to use a fixed correction factor. Based on 

these considerations, EPA is establishing the following approach with regard to ethanol 

corrections. First, EPA will permit measurement or the use of a fixed correction factor 

on an evaporative family by evaporative family basis. However, once the manufacturer 

selects an approach for any given evaporative family, that approach must be used in all 

subsequent testing of all vehicles certified using that data including carry over. For 

example, if a manufacturer chooses to measure the ethanol fraction for purposes of 

certification of a test group in a given model year, that same method must be used in any

manufacturer confirmatory testing as well as IUVP or IUCP testing of all vehicles in that 

test group. Alternatively, if a manufacturer uses the fixed correction factor in 

certification it must also use it for all evaporative emission tests covered by the 

requirement for a given test group and for all follow on testing. Second, the decision on 

measurement or correction factor must be uniform on a test group basis for all 

evaporative emission standards covered by the correction requirement. In this case this 

includes hot soak, diurnal, high altitude, running loss, and rig test measurements. Third, 

in terms of a fixed correction factor, EPA believes that the 1.08 value adopted by

California is consistent with the data and is specifying that value for hot soak plus diurnal 

(low and high altitude), running loss, and rig test measurement corrections for any testing 

conducted with 10 percent ethanol. Based on the data provided by the manufacturers, 

EPA is not requiring a fixed correction value or measurement for refueling, spit back, or 

canister bleed measurements for testing conducted with 10 percent ethanol. This aligns 

with the expectation that ethanol concentrations will be very low with FID-based 

 

375

 Moulis, C. (2012, January). SHED FID Responses for Ethanol. Memorandum to the docket. 

376 Passavant, G. (2013, October). Manufacturer Data on Ethanol Measurements in the SHED. 

Memorandum to the docket.
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measurements and that mass-based measurements will capture any ethanol adequately 

without a need for correction. Finally, EPA will use the method selected by the 

manufacturer in any confirmatory or surveillance testing. However, since corrections 

will always be zero or greater, no correction is needed to make a failure determination if 

the FID value exceeds the emission standard or FEL. With regard to the 1.08, EPA 

remains open to future revisions to this value, in coordination with CARB, if a fuller data 

set representative of various vehicle models, SHED FID ethanol response values, FID 

designs (analog vs. digital), ethanol calculation approaches (photo acoustic and 

impinger), and test sites demonstrates that a different value would be technically

appropriate and adequately conservative relative to the direct measurement methods 

permitted in 40CFR1065.

 For higher ethanol blends (such as E85), the regulation already specifies 

measurement and calculation procedures to adjust for this effect. We are not making any

changes to these procedures.

d. Vehicle Preconditioning for Nonfuel Hydrocarbon Emissions for the Tier 3 

Evaporative Emission Standards

The Tier 3 hot soak plus diurnal, leak, and canister bleed emission standards taken 

together are expected to bring about the widespread use of technology which effectively 

eliminates fuel vapor emissions. The fuel rig, canister bleed, and leak standards are not 

influenced by nonfuel hydrocarbon emissions from the vehicle. Nonfuel hydrocarbon 

emissions from the vehicle are measured as part of SHED emission testing, and are 

indistinguishable from fuel hydrocarbons when a FID is used to measure the 

concentration. The level of these nonfuel hydrocarbon emissions vary by vehicle and 

component design and material. These emissions arise from paint, adhesives, plastics, 

fuel/vapor lines, tires, and other rubber or polymer components and are generally greater 

with larger size vehicles. These nonfuel hydrocarbon emissions are usually highest with 

newly manufactured vehicles and decrease relatively quickly over time. 

Currently, manufacturers normally conduct some preconditioning to reduce or 

eliminate the effects of these nonfuel hydrocarbon emissions on evaporative emissions 

measurements in the SHED. In the past, this practice has not been addressed through 

regulatory provisions. However, given the stringent level of the Tier 3 hot soak plus 

diurnal evaporative emission standards, and that nonfuel hydrocarbon emissions are 

expected to be a significant portion of the hydrocarbon emissions measured in the SHED, 

EPA believes that some sort of preconditioning before certification testing is appropriate 

and that a regulatory provision addressing this practice is warranted. Providing some 

recognition of and allowance for this practice will help to create the proper balance 

between necessary and proper preconditioning to address high nonfuel hydrocarbon 

emissions and excessive preconditioning which could undermine the intent of the hot 

soak plus diurnal emission standard (~ 50 mg or less of fuel evaporative emissions). EPA 

believes the goal of evaporative emissions preconditioning should be to get nonfuel 

hydrocarbon emissions to what we call vehicle background levels. A working definition 
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of vehicle background level might be the level which will occur naturally twelve months 

after production. A provision in the regulations which addresses preconditioning reduces 

ambiguity for the manufacturers and could reduce or eliminate any uncertainty in the true 

meaning of certification test results. 

Manufacturer activity with regard to preconditioning often involves two practices. 

First, manufacturers in some cases “bake” their test vehicles at temperatures of 50 °C or 

higher for periods of up to ten or more days to accelerate the off-gassing of these nonfuel 

hydrocarbon emissions before testing is conducted. While this practice is common, there 

is no standardized method or protocol for this preconditioning prior to new vehicle 

certification testing. For example, some manufacturers bake for a set period of time in a 

climate chamber while others bake in the climate chamber and periodically measure 

nonfuel background in a SHED until an acceptable or stable level of nonfuel hydrocarbon 

emissions is achieved. Second, manufacturers often remove, modify, or clean certain 

components which are the largest source of nonfuel hydrocarbon emissions. 

Preconditioning could also include measures to eliminate minor fuel drips, spills, or other 

fuel remnants which occur as a result of vehicle preparation for testing.

We are not specifying standardized pre-conditioning practices or protocols with 

regard to addressing nonfuel hydrocarbon emissions before evaporative emission 

certification testing. However, we are finalizing general provisions in four areas. First, 

we specify in the regulations that preconditioning for the purpose of addressing nonfuel 

hydrocarbon emissions is permitted. Second, we specify that any preconditioning is 

voluntary. Third, we specify that if preconditioning is conducted, the details must be 

specified to EPA before certification testing, (i.e., at the time of the pre-certification 

planning meeting). The goal of this preconditioning should be to get nonfuel 

hydrocarbon emissions to vehicle background levels as discussed above. The specifics to 

be discussed with EPA could include details on vehicle baking practices such the 

temperature and time duration in the climate chamber and practices conducted as an 

alternative or complement to vehicle baking such as installing used tires (drive and spare) 

on certification vehicles, and allowing the windshield washer tank to be filled only with 

water. EPA’s goal in these discussions is to gain certainty that manufacturers are not 

preconditioning vehicles so severely that they create a level of nonfuel hydrocarbons that 

is artificially low and would not occur in use and thereby creating a false additional 

compliance margin for fuel hydrocarbons in the certification test. Fourth, except as 

discussed below we are providing in the regulations that no pre-conditioning is permitted 

for testing of any vehicle aged more than twelve months from its date of manufacture. 

This restriction for vehicles older than 12 months includes certification, confirmatory and 

in-use testing for any vehicle certified to the Tier 3 evaporative emission standards. For 

these vehicles, nonfuel hydrocarbon emissions will presumably be reduced to a stable 

level due to natural off gassing which begins after the vehicle is manufactured. 

Emissions from any replacement parts or other vehicle maintenance will presumably be 

encompassed within the margin below the standard created by this natural off-gassing.
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 EPA received several comments concerning the proposed restriction on preconditioning of vehicles older than 12 months from the date of manufacture. The Alliance 

of Automobile Manufacturers and the Association of Global Automakers asked that 

baking be permitted if such a vehicle is found to have identifiable contamination due to 

causes such as a fuel spill, refrigerant leak, or washer fluid leak and that the manufacturer 

be given the option to age the tires (tires only) from any vehicle where the tires are less 

than twelve months from manufacture as indicated on the sidewall. CARB asked that 

EPA only allow the use of an aged spare tire in any testing and not spare tire removal. 

EPA generally agrees with these commenters and is finalizing provisions for limited 

flexibility subject to EPA approval. Under these provisions manufacturers may be 

permitted to clean any spills or leaks but not to bake the entire vehicle. Baking of tires 

less than 12 months old may also be permitted with EPA prior approval. Vehicles must 

be tested with a spare tire in place since emissions from the spare tire were considered as 

the standard was developed. Manufacturers may exchange a new spare tire for one that is 

baked or aged. Finally, one manufacturer indicated that there may be circumstances 

where the base chassis for a certification vehicle was used in previous certification but 

that this base chassis was modified for a new model year and cleaned, reconfigured, and 

recertified with new components which affect background emissions.377 While EPA 

believes this would be a rare occurrence, regulatory provisions in this rule allow EPA to 

approve additional pre-conditioning for vehicles in this situation upon manufacturer 

request and justification.

e. Reciprocity with CARB

Over the past 15 years EPA’s “enhanced evap” test procedures have been based 

on testing with 9 pound per square inch (psi) RVP gasoline with test temperatures 

representing a summer day with peak temperatures of about 96 °F. CARB adopted the 

same basic procedures, but specified that testing should occur with 7 psi RVP gasoline at 

temperatures of up to 105 °F. EPA and CARB agreed that certification could be based on 

testing with either EPA or CARB conditions and that these provided equivalent 

stringency for purposes of evaporative control system design. However, the provision 

allowing for this equivalence of test data preserved EPA’s ability to also test with either 

EPA or CARB temperature conditions and related test fuels. CARB always specified 

EPA test conditions for refueling as they were deemed worst case. CARB recently 

changed their certification test fuel to a 7 RVP gasoline with 10 percent ethanol and as 

discussed in Section IV.F, we are changing the Federal certification test fuel specification 

to a 9 RVP gasoline with 10 percent ethanol.

 During the development of this FRM we carefully considered the practice of 

CARB/EPA reciprocity with regard to certification test fuels, hot soak plus diurnal test 

 

377 See public comment EPA-HQ-OAR-2011-0135-4299 and Passavant, G. (2013, October). VW E-mail to 

EPA Regarding Vehicle Preconditioning. Memorandum to the docket.
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procedures, running loss test procedures, and emission test results when it comes to 

evaporative emissions certification. Based on these considerations and the alignment of 

the ethanol content for the EPA and CARB certification fuels, we have decided to retain 

our current approach with regard to CARB/EPA reciprocity for evaporative and refueling 

emissions. EPA and CARB have agreed to continue accepting emission test data on 

each other’s test fuels and temperature conditions for certification such that a uniform 

national program for certification test fuel will be able to exist. For model years during 

the evaporative emissions standard phase-in discussed above (ending after the 2021 

MY), EPA will conduct any post certification testing on any vehicle in the Tier 3 

program manufactured in the 2015-2021 MYs using the fuel and temperatures used by 

the manufacturer for certification. This approach covers families certified using carry

over PZEV evaporative emissions data (through the 2019 MY) and LEV III Option 1 

certifications (through the 2021MY). Our program flexibility in the area of test fuels for 

hot soak plus diurnal, running loss and SHED rig/canister bleed emission standards is 

summarized in Table IV-25. After the 2021model year, EPA will retain the option to test 

on either set of temperatures/fuels. This applies to all evaporative emission standards (hot 

soak plus diurnal, running loss, and canister bleed). For the other emission standards 

(refueling, leak, spit back, and high altitude hot soak plus diurnal) EPA will use the test 

fuel used by the manufacturer through the 2019 model year. For the 2020 model year 

and later we may use Tier 3 fuel or California Phase 3 if its use is permitted for 

certification. Please refer to the regulatory text for specific provisions.

EPA will review all Tier 3 program evaporative emissions data. If the data shows 

that the EPA and CARB based test requirements give fully equivalent results, in the 

future we may revise our regulations so that a vehicle is always tested on the fuel used for 

its initial certification.

Table IV-25 Tier 3 Evaporative Emissions Program Options and Test Fuels

Vehicle 

Program

Start 

MY

Program 

Standards

Cert Fuel EPA test fuel for 

confirmatory, 

surveillance & IUVP

End MY 

for Use in 

Tier 3

PZEV 

zero 

evap.

2015 Hot soak + 

diurnal, 

running loss & 

SHED rig

CA Ph. 2 Fuel used by the 

manufacturer

After 

2019MY

LEVIII 

Opt. 1

2015 Hot soak + 

diurnal, 

running loss & 

SHED rig

CA Ph. 3 CA Phase 3 through 2019 

MY, after EPA may use 

Tier 3 or CA Phase 3

After 

2021MY

LEV III 

Opt. 2

2015 Hot soak + 

diurnal, 

running loss & 

canister bleed

CA Ph. 3 CA Phase 3 through 2019 

MY, after EPA may use 

Tier 3 or CA Phase 3

N/A
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Tier 3 2015 Hot soak + 

diurnal, 

running loss & 

canister bleed

Tier 3 Tier 3 N/A

As shown in Table IV-22, to qualify as a Tier 3 vehicle for evaporative emission 

purposes vehicles must meet the hot soak + diurnal, high altitude, rig/canister bleed, 

running loss, refueling, and spit back standards. The leak standard applies beginning in 

the 2018MY and the SHED rig/ canister bleed tests are program specific.

Generally, a vehicle test group using Tier 3 certification fuel and test procedures 

for meeting the various evaporative and refueling emission standards will qualify for 

inclusion in the Tier 3 evaporative emission standards phase-in. However, EPA 

recognizes that the California and federal evaporative emission standard programs are 

starting from different bases and that the transition provisions are different in some ways. 

For example, the EPA program starts in the 2017 MY but after that has the same basic 

program construct as CARB in 2018. However, prior to the 2017 MY, CARB has a ZEV 

program provision which will continue to bring zero evap technology into the fleet before 

the 2017 MY and CARB also allows early LEV III Option 1 and Option 2 evaporative 

emission certifications. To capitalize on this technology and to facilitate transition, we 

are finalizing provisions that any CARB evaporative emission test data from MYs 2015 

and 2016 PZEV zero evap certifications (hot soak plus diurnal and running loss) can be 

used in federal certification for those evaporative families through the 2019 MY. 

Similarly, we are finalizing provisions that CARB LEV III Option 1 certifications (hot 

soak plus diurnal and running loss) can be used in federal certification for those 

evaporative families through the 2021 MY. Assuming the vehicle test groups also meet 

the Tier 3 high altitude evaporative emission standards, the refueling emission standard, 

the spit back standard, and the leak standard when applicable, they could be included in 

the percentage phase-in calculations as Tier 3 vehicles. If the vehicles do not meet the 

Tier 3 evaporative emission requirements manufacturers could potentially sell them 

nationwide, but they could not be included as Tier 3 compliant vehicles in the percentage 

phase-in calculation. Table IV-22 provides a concise summary of the requirements a 

vehicle must meet to qualify as a Tier 3 vehicle during the program’s early, transition, 

and phase-in periods. 

 EPA proposed a similar provision for a manufacturer who elects to use the 

CARB test procedures and test fuels to meet the refueling emission standard. However, 

no manufacturer indicated interest in their comments and we have decided not to include 

reciprocity for this provision in the Tier 3 program. While experimental data based on 

field bench testing suggests that the CARB test fuel RVP and dispensed temperature 

together would give the same results as the EPA test fuel RVP and dispensed temperature 

there are no vehicle test data in the record at this time. CARB has always accepted 

refueling and spit back certification on EPA test fuel and will continue to do so in the 
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future. This provision would have added another layer of complexity to the program and 

was not necessary since the refueling and evaporative tests are done separately. 

f. Evaporative and Refueling Emission Standards for Various Fuels

The evaporative and refueling emission standards apply in different ways to 

different fuels. First, with regard to the evaporative emission standards, Clean Air Act

section 202(k) specifies that gasoline-fueled vehicles must be certified to evaporative 

emission standards. Section 202(a) authorizes EPA to establish evaporative emission 

standards for other fuels. Today evaporative emission standards apply to LDVs, LDTs, 

MDPVs, and HDVs fueled by gasoline methanol, ethanol, natural gas, and liquified 

petroleum gas (LPG). For the refueling emission standard the situation is quite different. 

Section 202(a)(6) of the Clean Air Act specifies that the refueling emission standards 

apply to all LDVs regardless of the fuel used. Section 202(a) of the Clean Air Act 

authorizes EPA to establish emission standards for other fuels and classes of vehicles. 

Prior to the Tier 3 final rule, the refueling emission standards applied to all vehicles less 

than 10,000 lbs GVWR regardless of the fuel used. 

In the NPRM, EPA requested comment on applying the refueling standards to all 

vehicles regardless of fuel used. This would include all volatile fuels.378 The evaporative 

standards apply today to all volatile fuels379 (except for diesel) and we asked for comment 

on explicitly including dedicated ethanol as well as fuel-cell vehicles, and electric 

vehicles. EPA also requested comment on applying the refueling and evaporative 

standards only to vehicles using volatile liquid fuels instead of all volatile fuels. 

EPA received four comments on this issue. One commenter expressed the view 

that evaporative requirements should be expanded to apply to volatile liquid fuels plus 

liquified petroleum gas (LPG) and liquified natural gas (LNG) while the three other 

commenters did not see the need to apply the requirements to any gaseous fueled vehicle 

or other vehicle using a non-volatile liquid fuel because these vehicle fuel systems are 

sealed and rarely vent during normal operation or never vent at all. 

As is discussed further in the Summary and Analysis of comments, based on the 

comments, the fuel properties, and current industry fuel system design practices, EPA has 

decided to retain the requirement that the evaporative and refueling emission standards 

apply to vehicles using any volatile fuel. For gaseous fueled vehicles (LPG and 

LNG/CNG vehicles), only the Tier 3 3-day hot soak plus diurnal and running loss 

standards apply. For the other volatile fuels all of the Tier 3 evaporative emission 

standards apply. For the refueling emission standard the requirements apply to all 

 

378 A volatile fuel is a volatile liquid fuel or any fuel that is a gas at atmospheric pressure; gasoline, 

methanol, ethanol, natural gas, and LPG are volatile fuels.

379 A volatile liquid fuel is a fuel that is liquid at atmospheric pressure and has a Reid Vapor Pressure 

higher than 2.0 pounds per square inch – gasoline, ethanol, and methanol.
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complete vehicles less than 10,000 lbs GVWR regardless of the fuel used. This is not 

being changed, except that the requirement will not apply to diesel-powered LDTs and 

HDVs vehicles. For vehicles over 10,000 lbs GVWR, the refueling emission standards 

will apply only to complete vehicles. This includes LPG, CNG, LNG, and dedicated 

ethanol or methanol vehicles. While the test procedures for these standards would apply, 

EPA is including regulatory provisions to permit manufacturers to certify based on 

related data, engineering analysis, and compliance with published consensus standards. 

We are not applying these requirements to electric or fuel cell vehicles.

For vehicles equal to or less than 8,500 lbs GVWR, the Tier 3 evaporative and 

refueling emission standards for alternative fuel vehicles apply to each vehicle of a 

vehicle evaporative/refueling family as the family is included in the manufacturer’s 

phase-in for the Tier 3 evaporative emission standards. For vehicles over 8,500 lbs 

GVWR, the application of the Tier 3 evaporative emission standards depends on the Job 

1(first build) date for the vehicle evaporative family. If the Job 1 date for a vehicle model 

is before the fourth anniversary date of the signature of the rule then the Tier 3 

evaporative emission standards do not apply until the next model year. If the Job 1 date 

is after the fourth anniversary date, the Tier 3 evaporative emission standards apply in 

that model year. This determines when the vehicle is to be included in the denominator of 

the percentage phase-in calculation. The refueling emission standard applies only to 

complete vehicles and we are applying the same phase-in requirements as for complete 

HDGVs. For complete vehicles between 10,000 and 14,000 lbs GVWR the refueling 

emission standard applies in the 2018 model year. For complete vehicles with a GVWR 

in excess of 14,000 lbs GVWR, compliance is required in the 2022 model year. Finally, 

for all small businesses, the Tier 3 evaporative and refueling emission standards do not 

apply until the 2022 model year. 

g. Other Changes and Future Considerations 

This rulemaking included consideration of several amendments or clarifications to 

existing requirements related to evaporative emissions. As part of this process, EPA has 

concluded that the following provisions warrant adjustment, clarification, or correction: 

 Even though the evaporative emission standards in 40 CFR part 86 apply to the 

same engines and vehicles that must meet exhaust emission standards, we require 

a separate certificate for complying with evaporative and refueling emission 

standards. An important related point to note is that the evaporative and refueling 

emission standards always apply to the vehicle, while the exhaust emission 

standards may apply to either the engine or the vehicle. Since we plan to apply

evaporative/refueling/leak standard and the recently adopted greenhouse gas 

standards to vehicle manufacturers, we believe it will be advantageous to have the 

regulations related to their certification requirements written together as much as 

possible to reduce burden and increase efficiency. Therefore, for 2015 and later 

model years, we are moving the emission standards and certification 

requirements for HDGVs from 40 CFR part 86 to the new 40 CFR part 1037, 
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which was originally used for greenhouse gas standards for heavy-duty highway

vehicles. This is not intended to change the requirements that apply to these 

vehicles, except as noted in this section. 

 Section 86.1810-01 contains specifications addressing whether diesel fuel 

vehicles can be waived from demonstrating compliance with the refueling 

emission standard through testing. In the existing regulation the potential for a 

waiver from testing depended on the diesel fuel having an RVP equal to or less 

than 1psi and the fuel tank having a temperature which does not exceed 130°F. 

We have examined this provision and are withdrawing the fuel temperature limit 

specification. Short of fuel spillage in the SHED, EPA sees no likelihood that a 

diesel fueled vehicle with RVP less than 1 psi could fail the refueling emission 

standard even at fuel tank temperatures above 130°F. This is due to the inherently 

low vapor pressure of diesel at these temperatures and the likelihood that vapor 

shrinkage conditions will occur in the fuel tank during refueling since the 

dispensed fuel will be much cooler than the tank fuel. 

 When adopting the most recent prior set of evaporative emission regulatory 

changes we did not carry through the changes applying evaporative emission 

standards to vehicles using methanol-fueled compression-ignition engines. This 

final rule corrects this oversight.

 We are finalizing provisions to address which standards apply when an auxiliary 

(nonroad) engine is installed in a motor vehicle, which is currently not directly 

addressed in the highway regulation. The approach requires testing complete 

vehicles with any auxiliary engines (and the corresponding fuel-system 

components). Incomplete vehicles are to be tested without the auxiliary engines, 

but any such engines and the corresponding fuel-system components will need to 

meet the standards that apply under our nonroad program as specified in 40 CFR 

part 1060.

 We are removing the option for secondary vehicle manufacturers to use a larger 

fuel tank capacity than is specified by the certifying manufacturer without recertifying the vehicle. Secondary vehicle manufacturers needing a greater fuel 

tank capacity must either work with the certifying manufacturer to include the 

larger tank, or go through the effort to re-certify the vehicle. This provision has 

not been used and is better handled as part of certification rather than managing a 

separate process. We are including corresponding changes to the emission control 

information label.

 We are revising the provisions for setting the vehicle air conditioning controls 

during the running loss portion of the evaporative emissions test cycle to simply

reference the specifications for exhaust emission testing described in 40 CFR part 

1066. This allows test labs to use a uniform set of test procedures for setting up 
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test vehicles. This change is expected to have no effect on the stringency of the 

running loss test.

 EPA regulations at §86.1824-01 permit manufacturers to develop their full-useful 

life deterioration factors for evaporative and refueling emission standards based 

on the use of good engineering judgment. These factors are additive in nature, and 

when added to the “undeteriorated low mileage” test value the sum must be less 

than the applicable emission standard or FEL. Manufacturers usually certify such 

that this summed value falls below the emission standard or FEL enough to 

provide a margin for in-use compliance and to address variability and other 

uncertainty. Regulations (at §86.1824-08) require that evaporative emissions 

durability assessments must employ gasoline fuel for the entire mileage 

accumulation period which contains ethanol in, at least, the highest concentration 

permissible in gasoline under federal law and that is commercially available in 

any state in the United States (currently E15). In their comments the Alliance of 

Automobile Manufacturers and the Association of Global Automakers asked to be 

able to use evaporative emissions deterioration factors from Tier 2/LEVII 

assessments even if the assessed or measured full life emission value used to 

determine the deterioration factor from the Tier 2/LEV II 2 testing is above the 

Tier 3/LEV III emission standard for the vehicle category of interest. (This 

situation, which is often referred to as line crossing, is not prohibited in the EPA 

regulation.) 380 Thus, EPA is permitting the use of this data but requires that: (1) 

the manufacturers use good engineering judgment in the testing used to develop 

their deterioration factors and the assessment and application of this data in 

developing deterioration factors, (2) the manufacturers use the 

evaporative/refueling emissions test fuel as stipulated in the regulations for Tier 3, 

and (3) the addition of the deterioration factor to the low mileage test result does 

not result in an exceedance of the emission standard or the FEL cap for that 

category of vehicles.

D. Improvements to In-Use Performance of Fuel Vapor Control Systems 

1. Reasons for Adding a Leak Test Standard

As emission standards approach zero, as in the “zero evap” standards discussed 

above, in-use performance becomes critical for vehicles to meet the standards over their 

useful life periods and provide the expected emission reductions. Fuel vapor control 

system leaks are not a new problem, in fact it was one of the main reasons for replacing 

the canister method for assessing evaporative emissions with the enclosure (SHED test) 

 

380. Passavant, G. (December 2013) Background Information on Background Information: Carryover of 

Emissions Data and Line Crossing. Memorandum to the docket. 
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method used today.

381

 However, as emission standards have become more stringent, test 

procedures have improved, and vehicle lifetimes have increased, any malfunction or 

deterioration in the system causes significant emissions increases. Even a small leak can 

cause large amounts of HC vapor. Therefore, the prevalence of leaks in the fleet can have 

a significant effect on the average evaporative emissions overall. 

As discussed in detail in the NPRM, recent laboratory and field data382 show very

high emissions from vehicles with liquid/vapor leaks. Field studies have indicated 

approximately 10 percent of overall fleet have significantly elevated evaporative 

emissions. The studies show that this frequency increases as vehicles age. The 

Coordinating Research Council (CRC) E-77 programs randomly recruited sixteen 

vehicles and almost half had some type of leak. Emissions related to these leaks grew in 

magnitude over the course of the program which lasted a few years. In addition, the EPA 

recently completed a test program to gather information on running loss emissions with 

implanted leaks of varying sizes, locations and fuel volatility.

383 Data from this study is 

not included in the modeling analysis for this final rule, but the results show that there are 

significant emissions from leaks while driving as the fuel tank temperature rises. 

Therefore the reductions from the future prevention of leaks will be larger than our 

current estimates. These data led EPA to examine the OBD-based evaporative system 

leak data available from I/M programs from several states to more accurately gauge the 

rate of leaks above the 0.020 inch monitoring threshold met by most manufacturers as a 

result of CARB’s 2004 model year OBD II requirements.384 These are important data 

because even a vehicle with a fuel/evaporative system leak as small as 0.020 inches

would be expected to fail the Tier 3 evaporative emission standard in a SHED test and in 

fact emit 4- 5 times above the Tier 3 emission standard on a daily basis due to the number 

of vehicle trips per day.

We examined data for vehicles meeting CARB’s OBDII evaporative emission 

leak monitoring requirements as well as either the CARB/EPA enhanced evaporative 

 

381 Rarick.T, “Evaporative Emission Enclosure (SHED) Procedure Analysis of Surveillance Program Data,” 

Evap 75-2, June 1975 and “Investigation and Assessment of Light-Duty Vehicle Evaporative Emission 

Sources and Control,” EPA -460/3-76-014, June, 1976.

382 CRC E-77 reports: Haskew, H., Liberty, T. (2008). Vehicle Evaporative Emission Mechanisms: A Pilot 

study, CRC Project E-77; Haskew, H., Liberty, T. (2010), Enhanced Evaporative Emission Vehicles (CRC 

E-77-2); Haskew, H., Liberty, T. (2010), Evaporative Emissions from In-Use Vehicles: Test Fleet 

Expansion (CRC E-77-2b); Haskew, H., Liberty, T. (2010), Study to Determine Evaporative Emission 

Breakdown, Including Permeation Effects and Diurnal Emissions Using E20 Fuels on Aging Enhanced 

Evaporative Emissions Certified Vehicles, CRC E-77-2c; DeFries, T., Lindner, J., Kishan, S., Palacios, C. 

(2011), Investigation of Techniques for High Evaporative Emissions Vehicle Detection: Denver Summer 

2008 Pilot Study at Lipan Street Station; DeFries, T., Palacios, C., Weatherby, M., Stanard, A., Kishan, 

S.(2013) Estimated Summer Hot-Soak Distributions for Denver’s Ken Caryl I/M Station Fleet.

383 Kishan, S., Sabisch, M., Stewart, J., Glinsky, G. (2014) Running Loss Testing with Implanted Leaks.

384 Weatherby, M., Sabisch, M., Kishan, S. (2014) Analysis of Evaporative On-Board Diagnostic (OBD) 

Readiness and DTCs Using I/M Data. Note: the data was presented in a docket memo for NPRM\ and is 

now part of a peer reviewed report.
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emission or Tier2/LEV II evaporative emission standards. Since the data were gathered

by the states under different protocols and time periods, the content of the data sets is not 

identical. To provide some degree of uniformity in our analysis, we examined the data 

for model years 2000 and later, but within each state we only looked at calendar years of 

data beginning after the initial state I/M exemption period had passed (2-6 calendar years 

depending on the state). Thus the analysis focused on I/M OBD information for calendar 

years 2004-2012.

Examined together, the data generally indicate the following. 

 For all our States analyzed, the trend lines show that between 2 – 4 percent of the 

vehicles entering the I/M program (at about 2 years old) have a “not ready” 

evaporative monitor. The percentage increased to between 8 – 11 percent as the 

vehicle aged to 8 years old with a rate increase of approximately 1 percent per 

year as the vehicle ages.

 The model years and time periods analyzed for the four States shows 

approximately 0.7-2.5 percent of vehicles overall with a “ready” evap monitor 

had one or more stored evap DTCs, indicating a potential evaporative emissionsrelated problem as defined in the OBD regulations.

 A further review of the data shows that, overall, in the three States with an 

enforced OBD program approximately 0.7 – 1.6 percent of vehicles with a 

“ready” evap monitor had one or more stored evaporative emissions related 

DTCs. The fourth State, which does not enforce the OBD test, had a higher 

percentage (2.5 percent) of evap monitor “ready” vehicles that had stored evap 

related DTCs. 

 For the same model years and time periods analyzed for the three States with 

enforced OBD programs, EPA estimates about 0.5 percent of vehicles with a 

“ready” evap monitor evaluated at four years old in an I/M program had a stored 

DTC. This rate increased at a rate of about 0.15 percent per year and was about 

1.1 percent for vehicles at 8 years old. For the fourth state, which does not 

enforce OBD evaporative results, EPA estimates about 1.4 percent of vehicles 

evaluated at four years old had a stored DTC. This rate increased at a rate of 

about 0.5 percent per year and was about 3.5 percent for vehicles at 8 years old. 

 Analyzing each state’s data for specific evaporative DTCs, over 50 percent of all 

evaporative codes were for evaporative system leaks. The second most common 

category (15-20 percent) involved some sort of error in the operation of the purge 

flow control which could also contribute to evaporative leaks. 

 The monitor “ready” rates are relatively uniform for all States analyzed, but the 

percentage of evaporative emissions related MILs illuminated and the percentage 

of evaporative system leak related DTCs were larger in the fourth State. EPA 
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believes this is the case because OBD is advisory only in this State’s I/M 

program, meaning that a vehicle could pass its I/M requirement with a MIL 

illuminated and not have to repair it.

In considering this information for the fleet as a whole, a few other factors must 

be considered. First, a vehicle can pass its I/M requirements (based on provisions of 

individual State I/M programs) with the evaporative emissions monitor “not ready”. 

Second, the vehicle can pass with a pending DTC. Third, it is not uncommon for vehicle 

repair related to an OBD MIL to occur just before I/M visits. Based on factors such as 

these, the values presented above are likely to be conservative on a fleet average basis. 

Beyond this, as discussed in the NPRM, earlier research conducted by EPA and the state 

of Colorado indicated that OBD is not designed to catch every evaporative system leak 

and sometimes misses leaks it should have found but did not for various reasons (some 

determined and some unknown).385 This suggests that overall leak prevalence is higher 

than indicated by the OBD data alone. 

Estimating a nationwide fleet average leak rate is possible with the limited data 

available if some informed assumptions are made. Only about 24.5 percent of vehicles in 

the U.S. are in I/M areas and of these only 20.8 percentage points (~4/5) are in areas 

which rely on OBD as part of the pass/fail protocol. There is at present no data on the 

prevalence of evaporative system leaks for vehicles in areas without I/M. However, 

based on these data it reasonable to assume that the rates in these areas are no less than 

for areas with I/M (where I/M mandates repair) and are likely similar to or larger than 

those for the one state analyzed where OBD is advisory only. Under those assumptions, 

the average leak rate across the country is much higher than for I/M areas alone. For 

example, if one considers data from the eight year age point in the I/M data for states 

which require repair, the leak prevalence rate is about 1.4 percent and in the state where 

OBD is advisory it is 3.5 percent. Weighted by the fleet percentages given above, this 

indicates a leak rate of about 3.0 percent in the fleet for the eight year age point. This is a 

conservative estimate based on historic evaporative I/M data.

386

The propensity for leaks in the vehicle fleet has the potential to reduce the 

benefits of the Tier 3 evaporative emission standards substantially. If on any given day, 

as few as 3 percent of Tier 3 vehicles have a leak(s) of 0.020 inches or greater this will 

cause in-use emissions equivalent to essentially all of the projected emission reductions

from the Tier 3 evaporative emission standards on that day.

387

 

 

385 Eastern Research Group (2013) Evaluation of the Effectiveness of On-Board Diagnostic (OBD) Systems 

in Identifying Fuel Vapor Losses from Light-Duty Vehicles.

386 USEPA (2014), “Development of Evaporative Emissions Calculations for Tier 3 FRM” memorandum to 

the Tier 3 docket.

387 See EPA memorandum: “Initial Comparison of Emission Rates from Vehicles with Fuel/Vapor System 

Leaks to Tier 3 Evaporative Emission Reductions, December, 2013.” 
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The leak standard we are adopting will help technology to meet the Tier 3 

evaporative emission standards and to improve in use durability. These technology

measures (see Section IV.C.3) coupled with the upgrade to the OBD evaporative 

emissions certification and monitoring requirements to signal problems at smaller 

threshold diameters (discussed in Section IV. E below) and additions to the IUVP 

program focused on testing a larger sample of vehicles for fuel/evaporative system leaks 

in IUVP than for evaporative emission standards alone will help to ensure improved inuse performance of evaporative emission control systems.

Based on the above discussion, there needs to be an increased focus on 

evaporative emissions durability. Nevertheless, there is no question of the value of OBD 

leak monitoring for evaporative systems, especially when owners complete needed 

repairs in response to the DTCs set. The I/M OBD statistics and associated in-use leak 

values discussed above would be higher without OBD evaporative system leak 

monitoring. However, these data suggest that EPA OBD regulations in place for 2004 

and later model year vehicles will not alone be sufficient to address concerns regarding 

the emission effects of vapor leaks from the fuel and evaporative control systems.388 

In the NPRM, EPA included a substantial discussion of the work we conducted on 

high evaporative emission rates and our rationale for the need for a leak standard to help 

address these concerns. No commenter challenged the data or the premises for our 

conclusion that a leak standard was needed. Manufacturers asked that the leak standard 

be phased-in with the Tier 3 evaporative emission standards and that use of upgraded 

OBDII evaporative system monitoring capability be included as part of the in-use 

verification program (IUVP) provisions. Both elements are contained in this final rule. 

CARB fully supported the proposed leak standard and test procedure and indicated its 

intent to adopt such provisions after the Tier 3 FRM is adopted. 

2. Nature, Scope and Timing of Leak Standard

The evaporative emission standards in this FRM will help to promote widespread 

use of improved technology and materials which will reduce evaporative emissions inuse. The new requirement for a leak standard and test procedure will help to ensure the 

durability of Tier 3 evaporative emission control systems nationwide. As discussed in 

the technological feasibility discussion in Section IV.C above, the actions of 

manufacturers to meet the Tier 3 evaporative emission standards are expected to address 

fuel/evaporative system design features which currently have a greater propensity for 

developing leaks and thus improve in-use durability for evaporative control systems 

 

388 Existing OBD regulations specify that if the fuel tank volume exceeds 25 gallons then the manufacturer 

may seek a larger leak detection orifice value. If a manufacturer seeks and is granted a larger value for 

OBD leak detection purposes, then that same numerical value becomes the leak standard value. We do not 

expect this value to exceed 0.040 inches.
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compared to vehicles meeting previous evaporative emission standards. The leak 

standard will provide added assurance that as the manufacturers design for “zero evap” 

standards they also design the systems to avoid leaks over the full useful life.

Based on the information described above concerning evaporative emissions inuse, we believe a leak standard is necessary to ensure that vehicles meeting Tier 3 

evaporative emission requirements not have evaporative emissions in excess of the Tier 3 

standards for their full useful life. Toward that end, we are finalizing a leak standard to 

be met both at new vehicle certification and in use for IUVP testing. The leak standard 

will apply beginning in the 2017 MY to vehicles in the 20/20 option for that year and in 

the 2018 MY and later model years to any vehicle certified to the Tier 3 evaporative 

emission standards or a CARB carryover vehicle counted toward the sales percentage 

phase-in requirements discussed in Section IV.C, including LDVs, LDTs, MDPVs, and

complete HDGVs up to 14,000 lbs GVWR. The standard will be applicable for the same 

useful life period as for the evaporative emission standards that apply to the vehicle. The 

standard will apply to vehicles using volatile fuel (e.g., gasoline, FFV, and methanol fuel 

vehicles, but not diesel or CNG vehicles).

To be compatible with CARB OBD requirements being met by most 

manufacturers and the OBD requirements included in this notice, we are specifying that 

the leak standard be expressed in the form of a cumulative equivalent orifice diameter. 

We are finalizing a value of 0.02 inches.389 The standard basically requires that the 

cumulative equivalent diameter of any orifices or “leaks” in the system not exceed 0.02 

inches. This is consistent with California OBD requirements (and those being finalized in 

this rule as well) that the OBD system be capable of identifying leaks in the 

fuel/evaporative system of a cumulative equivalent diameter of 0.020 inches EPA 

believes a standard at this level is feasible since earlier testing programs identified 

vehicles with essentially no leaks and it is essentially equivalent to that required for 

CARB OBD evaporative system leak monitoring. We are finalizing a leak standard of 

0.02 inches which with rounding is a bit less stringent than the 0.020 inch OBD 

evaporative system leak monitoring requirement. EPA believes this level of precision is 

sufficient to accomplish the air quality objective and yet provides some compliance 

margin between the standard and the monitor requirement such as is reflected through 

multipliers for the exhaust emission standards established for other OBD monitors. The 

leak standard will be specified to one significant digit (e.g., 0.02 inches) but will have to 

be measured and reported to at least two significant digits.

The leak standard will apply at the time of certification as well as during 

confirmatory and in-use verification program testing. We do not expect that new vehicles 

 

389 Existing OBD regulations specify that if the fuel tank volume exceeds 25 gallons then the manufacturer 

may seek a larger leak detection orifice value. If a manufacturer seeks and is granted a larger value for 

OBD leak detection purposes, then that same numerical value becomes the leak standard value. We do not 

expect this value to exceed 0.040 inches.
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being certified will have a leak problem, and since a vehicle with a leak would likely fail 

the evaporative emissions SHED test, there is little value in mandating a leak test at 

certification. Thus, EPA will permit a manufacturer to attest to compliance with the leak 

standard at certification.

To implement the leak standard within the existing regulatory structure a few 

minor rule changes are being made. First, existing EPA regulations such as those at 

§86.098-24, specify criteria for evaporative/refueling emission families. EPA believes 

this basic structure is appropriate for the leak standard, with the additional criteria that 

vehicles in the same evaporative/refueling family must use the same basic approach to 

OBD leak detection. Significantly different volume fuel tanks would likely also be a 

family determinant, but we believe this is already covered by the evaporative/ refueling 

family criteria. Second, since the leak standard is a pass/fail requirement and not an 

emission rate, there is no requirement for the application of a deterioration factor. Third, 

EPA requires that the manufacturers recommend two or more leak test points for each 

test group. One of these points should be near the canister/purge valve (ideally in the 

vapor line between the canister/purge valve and the fuel tank) and the other in the gas 

cap/fill pipe area. Three points are required for vehicles with two separate evaporative 

and refueling canisters such as non-integrated ORVR systems which employ two 

activated carbon canisters and four points are required for vehicles with dual fuel tanks 

and two separate evaporative/refueling control systems.

EPA believes that linking the timing of the leak standard to the beginning of the 

phase-in of the Tier 3 evaporative emission standards in the 2018 model year provides 

adequate lead time and is consistent with the technical rationale supporting the feasibility

of the Tier 3 evaporative emission standard. 

3. Leak Standard Test Procedure 

The fundamental concepts underlying fuel/evaporative system leak test are not 

new to the manufacturers. There is already a simple leak check in 40 CFR 86.608-

98(a)(1)(xii)(A) and in the past at least three states included a fuel/evaporative system 

pressure leak test in I/M programs. More importantly, all LDVs, LDTs, MDPVs and 

HDGVs manufactured today have the onboard capability to run a pressure or vacuum 

leak based check on the vehicle’s evaporative emission system as part of OBD 

evaporative system leak monitoring. These systems employ either positive or negative 

pressure leak detection pumps or operate based on natural vacuum for negative pressure 

leak detection. EPA is finalizing a test based on a similar concept of placing the system 

under a slight positive pressure (but from an external source), measuring the flow needed 

to maintain that pressure in the fuel/evaporative control system, and converting that flow 

rate to an equivalent orifice diameter. With regard to the test procedure we will first 

discuss where the leak test can occur in the FTP test sequence. We will then discuss how 

the test is to be conducted. EPA proposed this test procedure as part of the NPRM and 

discussed it extensively in the preamble to the proposed rule, and provided a full draft of 
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the Recommended Practice for comment as an Appendix to the RIA. No comments were 

received. We are finalizing this test procedure as proposed.390

First, when conducted, the leak test should be completed immediately following 

the first two preconditioning steps within the FTP sequence (see Figure B96-10 in 40 

CFR 86.130-96). Thus, the vehicle preconditioning steps for the leak test are: (1) fill the 

vehicle fuel tank to 40 percent of capacity using the appropriate certification test fuel and 

then (2) let the vehicle soak for a minimum of a six hour period at a temperature in the 

range of 68-86 °F. EPA requires that the test be conducted with 9 RVP E10 test fuel for 

both certification and IUVP.391 After preconditioning is complete, the leak test is 

conducted and the test sequence proceeds as prescribed in subpart B or testing is 

terminated if the purpose is only to conduct leak testing. EPA believes this modest level 

of preconditioning is sufficient to create standard conditions which enable repeatable and 

reliable measurement results. Preconditioning cannot include any prescreening for leaks 

nor will any tightening of fittings or connections be permitted. 

After preconditioning is complete, manufacturers then run the leak test. To fully

complete testing on a vehicle, two or more test points are required depending on the fuel 

evaporative system configuration. All points must pass for the vehicle test to be a pass. 

As discussed above, one of these points should be near the canister/purge valve (ideally 

in the vapor line between the canister/purge valve and the fuel tank) and the other in the 

gas cap/fill pipe area. Three points are required for vehicles with two separate 

evaporative and refueling canisters such as non-integrated ORVR systems which employ

two activated carbon canisters and four points are required for vehicles with dual fuel 

tanks and two separate evaporative/refueling control systems such as dual tank LDTs. If 

the fuel/ evaporative system has an embedded evaporative system test port then that point 

can be used. Also, a manufacturer can develop a test rig such as a “fill pipe extension” 

which screws into the fill pipe opening using cap threads at one end and on the other end 

has threads to screw the fill pipe vehicle cap in place. Within this extension there must 

be an access port for the leak test equipment to be attached. Thus, the full system could 

be tested without any direct intrusion or the need for a separate gas cap assessment. The 

manufacturer must specify the test points at the time of the pre-certification meeting. If 

the manufacturer selects an entry point which requires the fuel cap to be removed, then 

the cap will have to undergo a separate test as is now done in many I/M stations.392 In 

this case, tests from both points combined must pass the standard. Manufacturers 

commented that only one test point was needed, but when asked by EPA they offered no 

 

390 Smith, P. and Passavant, G., “Recommended Test Procedure and Supporting Testing Data for the 

Evaporative Emissions Leak Test”, December 2013.

391 This is the same preconditioning that is called for in existing 40 CFR 86 subpart B for exhaust, 

evaporative, and refueling emissions testing. EPA will consider permitting the leak standard to be evaluated 

using CARB LEV III test fuel if CARB ultimately adopts this requirement.

392 For related information see “IM240 & Evap Technical Guidance”, EPA 420-R-00-007, April, 2000. 
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data to counter that provided by EPA in the NPRM which showed the potential for 

different results at different test point locations for the same vehicle.

The procedure is conducted as follows:

 Calibrate the testing apparatus and otherwise verify testing apparatus is ready

and able to complete the procedure 

 Seal fuel system so as to pressure test entire system (purge valve, cap, etc.) 

 Attach test apparatus to vehicle’s fuel system at selected test point 

 Pressurize fuel system with nitrogen or another inert gas to at least 2.4 

kilopascals (kPa) 

 Allow flow and pressure to stabilize in accordance with specification provided 

in the regulatory text 

 Calculate effective leak orifice diameter from measured output flow rate and 

temperature and pressure data or use apparatus with built in computer 

providing an equivalent digital readout. Calculate to the nearest 0.01 inch. 

 Calculated effective orifice diameter must be less than or equal to the standard 

 If leak test is conducted at the fuel cap opening then the manufacturer must 

also show evidence that the vehicle’s fuel cap is performing properly.

393

 Use two or more separate test points, near the evaporative canister/purge valve 

and the other near the fuel cap are required. This is especially important if the 

fuel cap/fill neck area is isolated from the rest of the fuel/evaporative system 

as a result of the 40 percent fill or if dual tanks are not otherwise connected 

through vapor lines. 

 Tests can be void if the test apparatus fails, becomes disconnected, fails to 

maintain a stable flow rate or pressure, or the test was stopped before 

completion due to safety considerations or some other relevant vehicle issue. 

 

393 Such tests are done routinely in I/M stations using a commercially available apparatus. The gas cap leak 

rate may be determined by pressure loss measurement, direct flow measurement, or flow comparison 

methods and shall be compared to a pass/fail flow rate standard of 60 cubic centimeters per minute of air at 

30 inches of water column. The flow rate methods are referenced to standard conditions of 70 °F and 1 atm. 
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 Leak tests at all points (2 or more depending on the fuel tank/evaporative 

system configuration) must pass for a vehicle to pass. This includes 

performance within specification for the fuel cap if it is removed for testing.

The test procedure presented above is based on current fuel system designs. In 

the future, it is reasonable to expect changes in designs of the fuel systems such that the 

procedure above may need adjustment. EPA will monitor these fuel system changes and 

modify the test procedure provisions as needed. Furthermore, existing EPA regulations 

(see §1065.10(c)) contain provisions which provide the opportunity for manufacturers to 

seek approval for special or alternate test procedures if from a practical perspective their 

systems cannot be evaluated under EPA requirements or they have an approach deemed 

equivalent or better. Any such special or alternative procedures must be reported under 

§86.004-21(b)(9).

4. Certification and Compliance

As part of the Compliance Assistance Program (CAP 2000) in-use verification 

program (IUVP)394 the manufacturers began testing the evaporative emissions 

performance of small samples of in-use vehicles owned and used by the public. These 

regulations can be found at 40 CFR 86 1845-01, and 1845-04. In 2000, EPA extended 

this requirement to cover chassis-certified HDVs, which for these purposes are basically 

all HDGVs up to 14,000 lbs GVWR.395 The in-use testing for evaporative emissions 

started in 2004 for 2001 MY LDVs, LDTs, and MDPVs and in 2008 for 2007 MY 

chassis certified HDGVs. Current IUVP data for evaporative emissions (including LDVs, 

LDTs, MDPVs, and HDGVs up to 14,000 lbs GVWR) covers about 1800 vehicle tests. 

These data show that when evaluated in the laboratory using certification test procedures, 

the vast majority (over 95 percent) of the vehicles pass the evaporative emission 

standards to which they were certified. While this information is indicative of good in-use 

performance, it has limitations. First, the test results are for small sample sizes. For the 

approximately 150 million LDVs, LDTs, MDPVs, and chassis-certified HDGVs 

produced between 2001 (the start of the IUVP program) and 2010 (latest available data), 

only about 0.001 percent of vehicles were tested. Second, the IUVP regulations place 

limits on the age/mileage for vehicle testing. Each model year is tested in two “batches,” 

nominally at the one and four year age points. One year old vehicles must have at least 

10,000 miles and four year old vehicles must have at least 50,000 miles with at least one 

within the higher mileage group having an odometer reading of at least 75 percent of 

useful life (90,000 miles for most Tier 2 vehicles). With the even longer useful life 

periods under Tier 3, attention to in-use durability for evaporative systems becomes even 

more important. Including the leak standard within the IUVP protocol, as structured in 

the discussion below, will provide better information to EPA and manufacturers 

 

394 See 64 FR 23906 (May 4, 1999).

395 See 65 FR 59922-59924 (October 6, 2000).
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concerning evaporative system performance and help to focus manufacturer efforts on 

using designs and hardware with full useful life durability in mind.

a. In-Use Verification Program (IUVP) Requirements for the Leak Standard 

i. Introduction

We believe it is important to identify leaks since vehicles with leaks are expected 

to have daily emission rates above the Tier 3 evaporative emissions standards, and the 

recent laboratory and field data382 suggest a propensity for the diameter of vehicle leak 

orifice to get larger over time and thus to have even higher emissions. This is also 

important because evaporative leak emissions occur virtually every day whether the 

vehicle is driven or not. Thus identifying potential leak problems is important to 

capturing the emission benefits of the Tier 3 evaporative emission requirements.

Toward that end, EPA is including assessment of compliance with the leak 

standard within the IUVP program. In developing the proposed rule, we considered 

expanding the evaporative emission testing portion of the IUVP program as a means to 

assess leaks, but we decided to focus on the leak standard because it is less burdensome 

than a full evaporative emissions SHED test and is a cost effective step toward assessing 

many aspects of evaporative emissions performance in-use. 

EPA believes adding a leak test requirement does not create an unreasonable 

burden. The test procedure described above is simple to run, inexpensive to conduct in 

terms of equipment and labor, and can be completed relatively quickly compared to an 

evaporative emissions test. However, we are retaining the evaporative emissions testing 

requirements currently in IUVP to monitor broader evaporative control system 

effectiveness (e.g., purge, canister control efficiency, permeation). 
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ii. IUVP Test Requirements 

We are requiring that the leak test be conducted for each and every vehicle 

assessed in IUVP for exhaust emissions under 40 CFR 86.1845-04. This will begin for 

2017 MY vehicles meeting the leak standard under the 20/20 option and more fully in the 

2018 MY certifications for all test groups meeting the new leak standard. The leak test 

IUVP requirement includes the low and high mileage tests for any exhaust vehicle 

evaluated for exhaust emissions plus a requirement that there be at least one 

representative of each evaporative/refueling/leak family evaluated at each mileage/year 

point. We are finalizing this approach to implementing IUVP for the leak standard in lieu 

of creating a new set of requirements which would require another set of vehicles to be 

procured for testing. We are not including the leak test with any evaporative emissions 

test in IUVP, since a leak will be evident in the results of the evaporative emissions test.

The existing IUVP regulations at §86.1845-04, Table S04-07, call for test sample 

sizes on a sliding scale based on annual vehicle sales by test group. This can vary from 

zero for very small sales test groups to six vehicles for test groups with sales exceeding 

250,000. There are more exhaust emission test groups than there are 

evaporative/refueling test families and exhaust emission test groups may cover one or 

more of the same evaporative/refueling/leak families, so we expect to receive multiple 

leak test results for most evaporative/ refueling/leak families. This will expand the 

amount of IUVP data we receive in this important area and improve our ability to assess 

the overall leak performance for a given evaporative/refueling/leak family and the fleet as 

a whole.

As discussed above, EPA believes that the fuel and evaporative control system 

leaks are heavily influenced by age as well as design and other factors. EPA asked 

comment on extending the age point for leak testing for IUVP beyond the four year point 

to better assess this effect. However, in the past, manufacturers have expressed concern 

about the implications of testing older vehicles and about finding vehicles still within 

their warranty and recall liability periods. EPA believes further consideration of longer 

year test points is merited for exhaust, evaporative, refueling and leak tests but because 

such a change could potentially affect all four tests we have decided to defer that action 

to a broader IUVP program review. Extending the time point for the leak test alone 

would create a different programmatic test burden in terms of more vehicle procurements 

than the program laid out above.

iii.Assessment of IUVP Leak Emission Standard Test Results

The existing regulations contain provisions addressing follow-on testing 

requirements for exhaust emissions for vehicles which fail to meet various performance 

thresholds within IUVP (see 40 CFR 86.1846-01). As mentioned above, we expect that it 

will be common to get more than one leak test result over the course of each model year’s 

mileage testing point for each evaporative/ refueling/leak family as a result of the 

requirement to assess leaks with each exhaust IUVP test. However, the leak standard is 
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basically pass/fail at 0.02 inches and it is difficult to establish a threshold criteria for a 

pass/fail standard such as has been done for exhaust emissions where there is a multiplier 

applied to the level of the individual exhaust emission standard.

Given the importance of the leak standard in assuring in-use evaporative 

emissions control, we are finalizing a set of criteria for assessing leak standard results 

from IUVP. These criteria can be summarized as follows for each low and high mileage 

test point for each model year tested:

 lf 50 percent or more of all vehicles evaluated in an evaporative/refueling/leak 

emission family for any given model year pass the leak standard, testing is complete. 

This applies to cumulative testing for that family throughout the model year for that 

mileage group. This is consistent with the exhaust emission requirements for IUVP 

and EPA believes it is reasonable since vehicles are tested in the “as received” 

condition from consumers.

 If only one representative of the evaporative/refueling/leak family is tested in a 

mileage group for that model year’s vehicles and it passes the leak standard testing is 

complete. If that vehicle does not pass the leak standard a manufacturer may test an 

additional vehicle to achieve the 50 percent rate.

 If an evaporative/refueling/leak emission family fails to achieve the 50 percent rate, it 

is presumed that the family will enter into In-Use Confirmatory Testing Program 

(IUCP).

Before IUCP begins, the manufacturer may ask for engineering analysis 

discussions with EPA to evaluate and understand the technical reasons for the testing 

outcomes and the implications for the broader fleet. Technical information for these 

discussions could include but will not be limited to detailed system design, calibration, 

and operating information, technical explanations as to why the individual vehicles tested 

failed the leak standard, and comparisons to other similar families from the same 

manufacturer. Relevant information from the manufacturer such as data or other 

information on owner complaints, technical service bulletins, service campaigns, special 

policy warranty programs, warranty repair data, state I/M data, and data available from 

other manufacturer specific programs or initiatives could help inform understanding of 

implications for the broader fleet. As part of this process a manufacturer could elect to 

provide evaporative emissions SHED test data on the individual vehicle(s) that did not 

pass the leak standard during IUVP. With an adequate technical basis, the outcome of 

this engineering analysis discussion could result in an EPA decision not to require IUCP 

testing. 

We will operate within the basic structure of the IUCP program in the existing 

regulations. Prior to commencing IUCP testing the manufacturer, after consultation with 

EPA submits a written plan describing the details of the vehicle procurement, 

maintenance, and testing procedures. This plan could include inclusion of a hot soak plus 
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diurnal SHED test to supplement leak test results. EPA must approve this plan before 

testing begins. As prescribed in the IUCP regulations for exhaust, if five vehicles are 

tested and all pass the leak standard then testing will be complete. If all five vehicles do 

not pass, then five more are tested. More vehicles can be tested at the manufacturer’s 

discretion but all testing must be completed within the time period specified in the 

regulations. EPA and the manufacturer then enter into discussions regarding 

interpretation, technical understanding, and compliance/enforcement implications of the 

test results, if any. 

iv. Optional Test Procedure Approach for IUVP/IUCP

With the implementation of the OBD regulation changes in Section IV.E below 

regarding evaporative system leak rate monitoring, EPA is finalizing an optional 

approach to a portion of the leak test procedure. This optional testing approach is 

included in the IUVP/IUCP testing program for the leak standard, but will not be used for 

certification testing for the leak standard. EPA can also use this procedure for conducting 

compliance assessments. Under this optional approach manufacturers will be able to rely 

upon the operation of their OBD evaporative system leak detection hardware and 

operating protocols in lieu of running the stand alone in-use leak test to check for the 

presence of a 0.02 inch leak in the fuel/evaporative system.

Quite simply, if a vehicle is brought in for IUVP or IUCP testing and a scan tool 

query of the onboard computer indicates that the vehicle has successfully completed a 

full OBD-based evaporative system leak monitoring check within the last 750 miles and 

no evaporative system leak problems for any diameter above 0.020 inches are indicated 

(no pending or confirmed diagnostic trouble code(s) P0440, P0442, P0446, P0455, 

P0456, or P0457), the vehicle would be deemed to have met and passed the leak standard 

test requirement. However, if the system has not successfully completed a full OBDbased evaporative system leak check within 750 miles with no problem indicated then the 

manufacturer will have the option to run its OBD-based evaporative system leak check in 

the laboratory after prescribed preconditioning. This OBD-based approach is sometimes 

used in auto manufacturer dealerships and repair facilities to diagnose and fix evaporative 

system leaks found by the OBD system. If the vehicle completes the full OBD-based 

leak test in the laboratory then the vehicle’s pass/fail results for the 0.02 inch cumulative 

equivalent diameter orifice will be based on the OBD test result. This optional protocol 

can apply to every leak standard test after certification unless not approved by EPA for 

IUCP under 40 CFR 1846.01(i). Replicate tests will not be required or allowed but void 

tests could be repeated. 

Furthermore, EPA will permit the manufacturer to run the stand alone EPA leak 

test in several situations. First, manufacturers can conduct the stand alone test to confirm 

that a problem identified by the OBD-based evaporative system monitoring leak check is 

a leak and not a problem with the OBD leak monitor itself. Second, a manufacturer can 

run the stand alone EPA leak test to confirm that the leak value identified by the OBD 

system is truly above the level of the leak standard. Third, it can be used for vehicles 
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which have not successfully completed a full OBD-based evaporative system leak 

monitoring check within the last 750 miles. Fourth, it can be used to confirm that a DTC 

set within the last 750 miles actually indicates the presence of a leak(s) greater than the 

standard. However, if a manufacturer elects to use only OBD-based evaporative system 

leak based monitoring in its IUVP testing; these results will be the basis for decisions 

regarding IUCP. As required in the existing IUVP regulations, all test data whether OBD 

based or based on EPA’s stand alone test procedure must be reported to EPA.

There may be some advantages to this option since it employs a pressure/vacuum 

approach manufacturers understand and creates positive/negative pressures 

manufacturers have accommodated within their fuel/evaporative system. One potential 

downside is that under current designs vehicle engines will have to be operating to create 

the pressure or vacuum and because the engine is operating this will require the OBDbased leak test to be stand alone after the preconditioning sequence is complete. This 

will be more challenging for natural vacuum leak detection systems unless extended 

driving is involved to create the fuel system heat needed for a natural vacuum event or 

this is done through a climate chamber or SHED based diurnal heat build.

Allowing for this approach raises at least two implementation questions. The first 

is related to the value of conducting the OBD-based test for a vehicle with a confirmed or 

pending leak DTC already set in the computer and/or an MIL indicated. In this case, 

EPA will permit the manufacturer to run the OBD-based leak test and/or the stand alone 

EPA leak test or concede that the vehicle will not pass the leak standard and count the 

result. Second is the question of gas caps. This is among the most common codes found 

in OBD records and is often related to operator error such as not tightening the gas cap 

properly. Codes of this nature have no value in this leak assessment, so a manufacturer 

will be permitted to correct the problem before testing and clear this OBD code before 

testing or run the stand alone EPA leak test. 

E. Onboard Diagnostic System Requirements

1. Onboard Diagnostic (OBD) System Regulation Changes - Timing

EPA first adopted OBD requirements for 1994 and later model year LDVs and 

LDTs. While EPA has extended its requirements from LDVs and LDTs to larger and 

heavier vehicles,396 EPA’s last broad upgrade to its basic OBD regulation was in the 2005 

timeframe. Since that time, CARB has adopted and the manufacturers have implemented 

a number of additional provisions to enhance the effectiveness of their OBD programs. 

These provisions include new requirements for OBD evaporative system leak detection 

as well as provisions to help insure that systems are built and operate as designed over 

 

396 EPA’s OBD regulations for LDVs, LDTs, and MDPVs, are found at 40 CFR 86.1806-05. EPA has also 

adopted OBD requirements for incompletes and heavier vehicles (greater than 14,000 lbs GVWR) (see 74 

FR 8324, February 24, 2009 and 40 CFR 86.010-18). 
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their full useful life, give reliable results (find and signal only true deficiencies), and 

operate frequently during in use operation. It is permitted in existing EPA regulations 

and is common practice for the industry to certify their OBD systems with CARB and for 

EPA to accept CARB OBD certifications as satisfying EPA requirements. EPA is 

continuing that practice and we are updating our regulations to be consistent with the 

latest CARB regulations.

EPA proposed to adopt, with a few adjustments, the CARB regulatory

requirements related to OBD II (see California Code of Regulations (CCR) 1968.2 dated 

May 18, 2010). We received comment from CARB that since our NPRM was issued, 

they were s completing an update of their OBD II regulations and that EPA should adopt 

these provisions in lieu of the May 18, 2010 provisions.397 We have reviewed these 

updates and concur with the commenters, so we are adopting the provisions officially 

approved by CARBs Office of Administrative Law on July 31, 2013. We are also adding 

provisions and continuing the exceptions as discussed below. The changes we are 

adopting do not include any changes to requirements for engines used in vehicles over 

14,000 lbs GVWR or to vehicles over 14,000 lbs GVWR, except for HDGVs optionally

certified using chassis procedures. To be consistent with the manner in which the Tier 3 

exhaust emission standards are being implemented for the heavy-duty vehicles between 

8,501 and 14,000 lbs GVWR, the OBD requirements will be based on the Job 1 (first 

production) date for the vehicle/engine model. If the vehicle/engine model Job 1 date is 

before the fourth anniversary date of the signature of the Tier 3 rule the requirements will 

not be mandatory in that model year. If the Job 1 date is on or after the fourth 

anniversary of the signature date of the Tier 3 rule the OBD requirements will apply in 

that model year. The Tier 3 OBD requirements will apply to all 8,501-14,000 lb HDVs in 

the 2020 model year. To be consistent with the manner in which the Tier 3 exhaust 

emission standards 

We are taking this approach to OBD for three basic reasons. First, this is 

consistent with the goal of a national program and one vehicle technology for all 50 

states. Second, compliance with the current CARB OBDII requirements is now 

demonstrated technology, compliance with these requirements is common within the 

industry today, and we expect that to continue in the future with the 2013 CARB 

changes. Thus, the added burden is minimal since essentially all manufacturers certify

their CARB OBD systems nationwide with EPA. Third, the latest OBD systems run 

frequently on in-use vehicles to identify potential exhaust and evaporative system 

performance problems, so adopting these provisions will create the opportunity for OBD 

to serve a more prominent role in ensuring the Tier 3 emission standards are met in-use. 

 

397 The latest update of CARB’s OBD regulations was adopted on July 31, 2013. See section 1968.2 at 

http://www.arb.ca.gov/msprog/obdprog/obdregs.htm/
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Alignment with the existing CARB OBD II requirements will be required by the 

2017 MY, except as discussed below. Manufacturers requested a phase-in compliance 

approach in lieu of a fixed compliance date, but no specific justification was provided by 

the commenters and EPA could not establish a need for this accommodation since the 

most recent changes to CARB OBDII regulations (2013) did not meaningfully affect 

provisions regarding vehicles/engines under 14,000 lbs GVWR which have been in place 

since 2006. LDVs, LDTs, MDPVs and vehicles under 14,000 lbs GVWR already 

comply with CARB OBDII requirements and use the CARB certification as the basis for 

EPA certification. . 

There is an important link between OBD provisions related to evaporative 

emission control system leak monitoring and the leak standard. They each provide an 

important incentive to design fuel/evaporative systems with fewer propensities to develop 

leaks in use but each addresses the issue from a different perspective. The distinction is 

that the leak standard prohibits leaks of greater than 0.02 inches cumulative equivalent 

diameter, while the OBD evaporative system leak monitoring provision requires that the 

OBD system find leaks larger than 0.020 inches cumulative equivalent orifice diameter 

and notify the owner, but with no explicit requirement to repair the problem. Thus 

adopting a 0.020 inch cumulative equivalent orifice diameter aligns these two programs 

and, as discussed above, facilitates the use of OBD evaporative system leak monitoring 

hardware/strategy as an optional leak detection test procedure for in-use testing. 

With regard to OBD evaporative system leak detection, EPA received comment 

that we should permit a phase-in for compliance with the 0.020 inch evaporative system 

leak monitoring requirement. Even though the 0.020 inch leak monitoring requirement 

has been in place since the 2004MY for CARB OBDII, and essentially manufacturers 

have met it for years, the existing EPA regulation actually only requires monitoring at the 

0.040 inch threshold level. After considering the comments received, EPA is permitting 

a limited and minimal phase-in for the 0.020 inch leak detection criterion for the OBD 

evaporative system monitoring requirement. We are permitting this phase-in, because a 

few vehicle models still only meet the 0.040 inch monitoring threshold in their Federal 

configuration and complying with the 0.020 inch CARB OBD II requirement entails 

validating performance in high altitude and cold weather regimes not seen in California. 

Thus, the 0.020 inch requirement would be new for those few models currently certified 

only to the EPA evaporative leak monitoring requirement. We are, therefore, 

implementing the following phase-in provision for the 0.020 inch leak detection criterion 

for the OBD evaporative system monitoring requirement. First, if a vehicle model meets 

the 0.020 inch requirement in the 2016 model year it is not eligible for the phase-in 

provision. No backsliding is permitted. Second, for manufacturers with models not 

meeting the CARB OBDII evaporative system leak monitoring requirement in the 2016 

MY(see 13 CCR 1968.2(e)(4)), they will be permitted to delay product-wide compliance 

with the 0.020 inch leak provision of the evaporative system monitoring requirements 

until the 2018 model year by engaging in a voluntary early phase-in. This phase-in would 

begin in the 2016 model year and conclude in the 2018 model year at a 100 percent 

implementation rate. For example, a manufacturer could delay attaining 100 percent 
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compliance with the OBD evaporative system leak monitoring requirement until the 2018 

model year by complying in the 2016 model year using a percentage which is at least as 

large as the delay for the 2017 model year (e.g., 40% in 2016 MY, 60% in 2017MY, and 

100% in 2018MY).

2. Revisions to EPA OBD Regulatory Requirements

As discussed above, we are updating our OBD regulations to be consistent with 

current California OBD II requirements. We are incorporating by reference section 

1968.2 of the California Code of Regulations as adopted July 31, 2013 (13 CCR 1968.2). 

This includes paragraphs (c) through (j) in their entirety. These paragraphs are entitled: 

(c) Definitions, (d) General Requirements, (e) Monitoring Requirements for 

Gasoline/Spark Ignited Engines, (f) Monitoring Requirements for Diesel/Compression 

Ignition Engines, (g) Standardization Requirements, (h) Monitoring System 

Demonstration Requirements for Certification, (i) Certification Documentation, (j) 

Production Vehicle Evaluation Testing. The substance of many of these provisions is 

already contained in existing EPA OBD requirements for LDVs, LDTs, MDPVs, and 

complete HDGVs less than 14,000 lbs GVWR.398 399 EPA will continue to accept 

certifications with CARB OBD requirements as satisfying EPA OBD requirements. 

The most noteworthy changes we are finalizing are summarized below. The CCR 

below is the California Code of Regulations cite for each pertinent provision.

 EPA is adding a 0.020 inch leak detection monitoring threshold upstream of the 

purge valve for all 4 vehicle categories LDV, LDT, MDPV, and complete 

HDGVs up to 14,000 lbs GVWR except for those with fuel tanks larger than 25 

gallons capacity (see 13 CCR 1968.2(e)). OBD leak monitoring systems will have 

to identify, store, and if required signal any leak(s) equal to or greater than 0.020 

inches cumulative equivalent diameter. This will thus include diagnostic trouble 

codes (DTC) P0440, P0442, P0446, P0455, P0456, and P0457.

 EPA is incorporating by reference the full array of rate based monitoring 

requirements (see 13 CCR1968.2 (d)(3)-(6)). Meeting the rate based monitoring 

requirements will help to insure that, even with enable criteria, the exhaust and 

evaporative system monitors run frequently enough that on average a problem 

would be identified and signaled to the owner in operation within two weeks. This 

will help to improve the fraction of time monitors are ready to find a potential 

problem.

 

398 MDVs in the CARB regulations basically incorporate MDPVs and complete HDGV less than 14,000 lbs 

GVWR as defined by EPA.

399 We are not changing the requirement for incompletes and vehicles with a GVWR above 14,000 lbs. 
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 EPA is incorporating by reference provisions regarding monitoring system 

demonstration requirements for certification. We are incorporating by reference 

CARB provisions in this area and accepting submissions to CARB for purposes of 

compliance demonstration (see 13 CCR 1968.2(h)). Adopting current CARB 

monitoring system demonstration requirements assures that monitoring systems 

operate as designed when installed on certification vehicles.

 EPA is incorporating by reference the CARB production vehicle evaluation data 

program. This program requires manufacturers to demonstrate that the OBD 

system functions as designed and certified when installed on production vehicles. 

(See 13 CCR 1968.2(j)).

In addition, we are adding two new requirements, and retaining three 

minor exceptions. Each of these actions is described separately below.

 We are adding the requirement that before certification a manufacturer must 

demonstrate the ability of its OBD leak monitoring system to detect and report a 

0.020 inch leak in the fuel/evaporative system. Current CARB protocols within 13 

CCR 1968.2(h)(3) do not require this demonstration as part of certification. This 

requirement helps to ensure the OBD system’s capability to function as designed 

and the OBD-based evaporative system leak monitoring hardware to be used as an 

optional test procedure for IUVP testing for the leak standard. This requirement 

being added for the same vehicles that are subject to monitoring system 

demonstration requirements for certification under CARB OBD regulations under 

1968.2(h)(3).400 EPA test procedures are contained in 40CFR 86.1806-17(b). In 

the spirit of aligning CARB and EPA OBD provisions, if CARB ultimately adopts 

this demonstration requirement and CARB’s test procedure provisions fulfill the 

purpose of the EPA requirement, EPA will strongly consider proposing to adopt 

the CARB test procedures in lieu of those in 40 CFR 86.1806-17(b). 

This requirement applies to any vehicle test group certified to the OBD 0.020 inch

evaporative system leak monitoring requirement. Since the regulation requires 

only a relative few test groups each model year per manufacturer, we will permit 

the manufacturers either to meet the requirement for the remainder of its test 

groups on production vehicles of a previous model year which used the identical 

monitoring hardware and strategies or to certify by attestation that each of their 

remaining test groups meets the requirement based on development, calibration, 

and other information. If a manufacturer chooses to certify by attestation for 

some test groups for a given model year, the regulations are structured such that 

 

400 Passavant,G. (January, 2014). “Development of 0.020” Evaporative Leak Monitoring System 

Demonstration Requirement Test Procedure”. Memorandum to the docket.
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over several model years a manufacturer would evaluate through testing all test 

groups as new groups are selected in subsequent model years. 

 For the OBD evaporative system leak monitoring requirement, EPA is 

establishing a requirement for a scan tool readable function (a new InfoType $14 

in Service $09 of SAE J1979DA) which can be used to obtain the distance 

traveled since the OBD leak monitoring diagnostic was last completed 

successfully, i.e., the system passed or failed (identified any leak above 0.020 

inches) during that monitoring event (unless it is otherwise already required in 

other OBD system modes). The purpose of this requirement is to facilitate 

implementation of the leak standard within IUVP, by permitting the use of OBD 

evaporative system monitoring results as a tool to make pass/fail determinations 

during IUVP. As discussed in section IV.D above, if a vehicle successfully 

completed an evaporative system leak monitoring within the most recent 750 

miles then the manufacturer could use this result for its IUVP requirement for the 

leak standard. EPA asked for comment on how best to implement this 

requirement within the OBD system, in what model year(s) it should be required 

and to which vehicle classes it should apply.

Manufacturers supported this requirement, and suggested a lower cost approach 

which we are adopting in the final rule. Rather than requiring that the distance and 

monitoring results be stored in NVRAM to avoid false results based on a user 

induced code clear or battery disconnect, the manufacturers suggested that the 

“distance since evap monitoring decision” InfoType be reset to the maximum 

value ($FFFF/65,535km) when codes are cleared or after a reprogramming event 

(e.g., battery disconnect). The InfoType would be reset to zero km when an 

evaporative monitoring pass/fail decision is later made, allowing the mileage to be 

read directly at IUVP. In the usual situation where no user induced code clear or 

reprogramming event (e.g., battery disconnect) occurred, the mileage since the 

last decision could be read directly. In either circumstance, the presence of an 

evaporative system leak related DTC (P0440, P0442, P0446, P0455, P0456, and 

P0457 or manufacturer specific equivalent DTC) will indicate a failure and the 

lack of such a DTC will indicate a pass. The mileage and the pass/fail results will 

then be taken together for purposes of the 750 mile option in the IUVP assessment 

for the leak standard.401

This requirement applies to all vehicle categories subject to the leak test including 

LDVs, LDTs, MDPVs, and complete HDGVs less than 14,000 lbs GVWR. 

Manufacturers commented that this requirement should apply only to vehicles/test 

groups meeting the leak standard. Since the leak standard phases-in between 

 

401 Passavant, G. (January, 2014). “Manufacturer Input on Distance Since Last Evaporative Monitoring 

Decision”. Memorandum to the docket.
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2018 and 2022 model years (2017 for manufacturers using the 20/20 evaporative 

emission option), a manufacturer may phase-in compliance with this requirement 

as well.

 The minor exceptions which are contained in EPA’s existing OBD regulations are 

to be continued. Compliance with 13 CCR 1968.2(d)(1.4), pertaining to tampering 

protection is not required. Also, the deficiency provisions of 13 CCR 1968.2(k) 

are not being adopted. In addition, demonstration of compliance with 13 CCR 

1968.2(e)(15.2.1)(C), to the extent it applies to the verification of proper 

alignment between the camshaft and crankshaft, will apply only to vehicles 

equipped with variable valve timing. For all model years, the deficiency

provisions of paragraph (i) of the existing EPA regulations apply only to 

alternative fuel vehicle/engine manufacturers selecting this paragraph for 

demonstrating compliance.

These changes, taken together will improve the performance, reliability, general 

utility, and effectiveness of OBD systems for Tier 3 exhaust and evaporative emission 

controls. Furthermore, these changes create the opportunity for OBD evaporative system 

leak monitoring systems to serve a more prominent role in ensuring compliance with the 

leak standard. EPA believes that they can be implemented for minimal cost since most 

manufacturers are meeting them today and will have to for LEV III vehicles. The 

provisions we are incorporating by reference give manufacturers the flexibility to seek a 

revision to the emission threshold for a malfunction on any diagnostic required if the 

most reliable monitoring method developed requires a higher threshold to prevent 

significant errors of commission in detecting a malfunction.402 Any decision on a 

potential exception would be preceded by a consultation between EPA and CARB. 

As discussed below, the OBD requirements will apply to small entities in the 

2022 model year, if they choose to take advantage of one of the revised implementation 

schedules for small volume manufacturers and small businesses. However, as is the case 

for larger manufacturers, no backsliding is permitted meaning that if they voluntarily

meet the OBD requirements on their Federal configurations in the 2016 model year as a 

result of compliance with CARB regulations they must continue to meet the requirements 

on the Federal configurations in the 2017 and later model years. Small alternative fuel 

converters will still be able to meet the OBD requirements using the provisions of 40 

CFR 85 Subpart F. Finally, it should be noted that as CARB updates its OBD regulations 

in the future EPA will consider these changes and propose to adopt them or incorporate 

them by reference, if appropriate.

 

402 See 13 CCR 1968.2 (e)(17).
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3. Provisions for Emergency Vehicles

It is common for emergency vehicles such as law enforcement, medical response, 

and fire protection vehicles operated by government entities to be derived from similar 

publicly available vehicle configurations. However, these vehicles often have chassis 

configurations, auxiliary equipment packages, and performance requirements different 

from the standard publicly available configurations. These emergency response vehicles 

typically meet the various EPA emission standards based on the engineering calibrations 

and emission control hardware used in the publicly available configuration. OBD 

requirements also apply to these vehicles and occasionally their unique design and/or 

operating characteristics may prevent them from meeting one or more of the various 

OBD requirements. 

In comments on the NPRM, one manufacturer raised a concern that EPA’s 

proposed adoption of the current CARB OBDII requirements for the 2017 model year 

would create a compliance problem for two of their law enforcement vehicle 

configurations. These two vehicle configurations cannot meet one element of the current 

CARB OBDII requirements (CCR 1968.2 (e)(6.2.1)(C)) without compromising the 

performance expected by law enforcement personnel.403 To address this issue CARB 

provided these vehicles an exemption from this provision, by permitting it to meet 

Federal requirements as permitted by the California Vehicle Code. This solved the 

problem because the CARB OBD II provision of interest did not exist within the Federal 

OBD requirements at that time.

This raises both a near term and a broader policy issue related to emergency

vehicles. First, we are incorporating a definition for emergency vehicle that is specific to 

the Tier OBD requirements.404 Second,, with regard to the two law enforcement vehicle 

configurations identified by the manufacturer, EPA has reviewed the manufacturer’s 

technical information and agrees with CARB’s previous assessment.405 Thus, EPA will 

grant the manufacturer a three model year exemption from the requirement as requested 

by the manufacturer (MY2017-2019 inclusive). Specifically, we are delaying the need to 

comply with the requirements of CCR 1968.2 (e)(6.2.1)(C)- incorporated by reference by

EPA- until the 2020MY for any emergency vehicle which does not meet the requirement 

in the 2016 model year. This specifically applies to the two test groups identified by the 

commenter. Second, in a broader context, there is a need to address the potential future 

need for a deficiency or an exemption for emergency response vehicles. If CARB grants 

 

403 See Ford Motor Company comments on the Tier 3 NPRM at EPA-HQ-OAR-2011-0135-4349.

404 For the Tier 3 OBD requirements, emergency vehicle means a motor vehicle manufactured primarily for 

use as an ambulance or combination ambulance-hearse or for use by the United States Government or a 

State or local government for fire protection or law enforcement. 

405 Passavant, G, (January, 2014). Information Related to CARB AFRIM OBD Requirements for 

Emergency Vehicles. Memorandum to the docket.
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a deficiency for emergency response vehicles under CCR 1968.2(k) we would expect this 

to be done in consultation with EPA. Furthermore, we are incorporating provisions to 

address a potential situation where an emergency vehicle needs a deficiency (a temporary

or permanent allowance for manufacturers to be non-compliant with a specific 

requirement of the OBD regulations as long as certain requirements are met) or 

exemption which is not addressed by CARB under CCR 1968.2(k). EPA is adopting a 

provision which authorizes us to address these circumstances based on an application 

from the manufacturer. Under this provision, EPA may approve a request for a 

deficiency or in extreme circumstances a temporary or potentially permanent exemption 

from a given OBD requirement. In considering decisions to approve/disapprove this 

request, EPA will consider the provisions of CCR 1968.2 (k)(1) plus engineering 

information and vehicle emission and performance data provided by the manufacturer 

which demonstrates significant vehicle engineering or system performance issues (e.g., 

vehicle speed, , acceleration, handling, safety, fuel economy, cost) related to complying 

with the OBD requirements. 

4. Future Considerations

EPA and CARB coordinate closely on OBD II requirements. When changes to 

the requirements occur, CARB provisions often precede those from EPA. Since LEV III 

begins before Tier 3, EPA expects that CARB will revise any OBD II requirements 

related to the LEV III before EPA would do so for Tier 3. EPA expects to work with 

CARB on any potential changes to OBD II requirements related to LEV III and to 

consider proposing such changes in a future action since we expect great commonality

between Tier 3 and LEV III exhaust and evaporative emission control systems. Two 

presentations related to CARB’s initial thinking for LEV III related OBDII revisions are 

available in the docket.406 In the interim, for any Tier 3 exhaust emission bin which does 

not have a corresponding bin value in the Tier 2 program, the threshold for the exhaust 

emission malfunction criteria is that of the next higher bin in the Tier 2 regulation as 

prescribed for the latest model year in CCR 1968.2(e)(1)-(3) . 

In the NPRM, EPA discussed the basics of evaporative emission control 

technology and laid out concerns regarding the loss of evaporative and refueling emission 

control which occurs if a canister is not purged. This can potentially occur if the purge 

hardware fails or if the flow of purge air through the canister is impeded by foreign 

matter collecting at the inlet port or on the carbon itself, canister poisoning due to fuel or 

water intrusion, or activated carbon breakdown from phenomena such as road vibration. 

Failure of purge hardware is already covered by OBD and a recent study indicates that 

 

406 McCarthy,M. , “CARB Light-duty OBD Regulation Update”, SAE 2012 Onboard Diagnostics 

Symposium, Nov 2012 and Remenus, M., “CARB Light-duty OBD Regulation Update”, SAE 2013 

Onboard Diagnostics Symposium, September 2013.
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this is a relatively rare evaporative system problem.407 Failure of the activated carbon to 

purge due to problems such as those mentioned above are not covered by OBD. EPA is 

undertaking a study to better characterize the causes and frequency of such potential 

problems, and may propose in a future rulemaking an OBD-based monitoring 

requirement related to activated carbon/canister capture should the study indicate a 

significant frequency of loss of canister efficiency in-use and loss in emissions control 

relative to other evaporative system failure modes. 

In the NPRM we also asked for comment on several other issues related to the 

role of OBD in future technology fuel/evaporative control systems. This included 

pursuing a monitoring threshold less than the 0.020 inches cumulative diameter that we 

are finalizing in this notice for non- pressurized and pressurized fuel systems. We asked 

about the feasibility and cost of requiring the OBD leak detection monitoring system to 

detect and signal the presence of a smaller diameter orifice, such as 0.010 inch upstream 

of the purge valve for a pressurized system with a designed in-use operating pressure 

threshold in excess of 0.36 psi (10 inches water). Also, for the pressurized system, we 

asked for comment on a potential provision to require that the fuel tank vent to the 

canister at key off if the OBD system identifies a leak. In their comments manufacturers 

indicated concerns about the need for such provisions or their value in reducing 

emissions relative to current requirements. EPA believes both of these provisions merit 

further investigation, but at the present time we lack the data to assess the feasibility and 

emission reduction benefits associated with each approach and so are not taking action on 

them.

Finally, in the NPRM we sought input on whether the operation of a vacuum 

pump or similar device used to assist or supplement vehicle engine vacuum purge or any 

device otherwise used to enhance or control purge flows, rates, or schedules should be 

required to be monitored as part of OBD. In their comments the manufacturers indicated 

their view that this would be covered by current OBD provisions, and we are not taking 

further actions. Emissions Test Fuel

F. Emissions Test Fuel 

In-use gasoline has changed considerably since EPA last revised specifications for 

the gasoline used in emissions testing of light- and heavy-duty vehicles. Sulfur and 

benzene levels have been reduced and, perhaps most importantly, gasoline containing 10 

percent ethanol by volume (E10) has replaced non-oxygenated gasoline (E0) across the 

country. This trend has had second-order effects on other gasoline properties. In-use fuel 

is projected to continue to change as refiners adjust their gasoline production to reflect 

 

407 Weatherby, M., Sabisch, M., Kishan, S. (2014) Analysis of Evaporative On-Board Diagnostic (OBD) 

Readiness and DTCs Using I/M Data.
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the renewable fuel volumes required under the RFS2 program, as well as further sulfur 

reduction under the Tier 3 rule.408 As a result, we are updating federal emission test fuel 

specifications to better match in-use fuel. The revised test fuel specifications apply for 

exhaust emissions testing, fuel economy/greenhouse gas testing, and emissions testing for 

non-exhaust emissions (with some exceptions discussed elsewhere in this preamble, e.g., 

for refueling tests in flex-fuel vehicles). The revised gasoline specifications, found at 

§1065.710 and discussed below, apply to emissions testing of light-duty cars and trucks 

as well as heavy-duty gasoline vehicles certified on the chassis test, where the vehicles 

are certified to the Tier 3 standards.409

1. Gasoline Emissions Test Fuel: Ethanol Content and Volatility

a. Emission Test Fuel Ethanol Content

In the NPRM, EPA proposed that the emissions test gasoline be changed from E0 

to E15 as a forward-looking position based on indications following the 2011 E15 waiver 

decision that the market would move in that direction.410 Since the time when we 

developed the proposal, several relevant factors have led EPA to reconsider that position, 

including limited proliferation on a national scale of stations offering E15 and the 

complexities E15 test fuel would introduce for long-term harmonization of the Tier 3 

vehicle emission regulations with California’s LEVIII program (which uses E10 for 

emissions testing).

We received comments supporting use of E10 as emissions test fuel from the 

automotive and oil industries, as well as states and NGOs citing the fact that this was 

most representative of current market conditions. Other stakeholders involved in fuel 

marketing and distribution cited significant infrastructure cost and liability concerns in 

making E15 widely available at existing stations. Ethanol industry commenters generally

supported E15 certification fuel as proposed, but provided no specific timeline on which 

this blend level would become representative of in-use fuel. The most recent surveys of 

the market show that E10 now comprises nearly 100% of in-use gasoline, with very small 

 

408 See 78 FR 49794 (August 15, 2013) for the latest renewable fuel requirements under the RFS2 program.

409As discussed elsewhere in Section IV, we are also generally requiring the use of Tier 3 test fuel in 

conducting exhaust, evaporative, and refueling emissions testing of heavy-duty gasoline engines certified 

on an engine dynamometer. These could include engines installed in incomplete Class 2b and Class 3 

vehicles and engines used in vehicles above 14,000 lb GVWR.

410 EPA issued a waiver allowing E15 to be introduced into commerce for use in MY 2001 and newer lightduty motor vehicles. On July 25, 2011, EPA finalized regulations to mitigate the potential for misfueling 

of vehicles, engines, and equipment not covered by the E15 waiver, i.e., MY 2000 and older light-duty

motor vehicles, all heavy-duty gasoline vehicles and engines, motorcycles, and all gasoline-powered 

nonroad products (which includes boats).410 Two of the required mitigation measures are a label for fuel 

pumps that dispense E15 to alert consumers to the appropriate and lawful use of the fuel and a prohibition 

on the use of E15 by consumers in vehicles not covered by the waiver, excluding flexible fuel vehicles 

(FFVs). For more details, see 76 FR 44406 (July 25, 2011).
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amounts of E0 and E15 being sold in limited areas where there is specific interest.411 

Based on this information and considering comments, EPA is finalizing E10 as the 

ethanol blend level in emissions test gasoline for Tier 3 light-duty and heavy-duty 

gasoline vehicles. We will continue to monitor the in-use gasoline supply and based on 

such review may initiate rulemaking action to revise the specifications for emissions test 

fuel to include a higher ethanol blend level. 

As discussed above in Sections IV.A.7.d (tailpipe emission testing) and IV.C.5.b 

(evaporative emission testing), we are requiring all light-duty and chassis-certified heavyduty gasoline vehicles to be certified to Tier 3 standards on federal E10 test fuel. As 

described in those sections, EPA will accept emission certification test results performed 

according to CARB’s LEVIII procedures including CARB’s E10 test fuel. Confirmatory

and in-use exhaust or evaporative testing of vehicles certified on CARB’s E10 test fuel 

will be performed using that same test fuel through MY 2019. After MY 2019, EPA will 

continue the practice of accepting emission data at certification on the LEVIII test fuel; 

however confirmatory and in-use testing may be performed using Tier 3 E10 test fuel at 

the discretion of the Agency. 

b. Certification Fuel Volatility (RVP) Specification

In deciding to finalize E10 as the emissions test fuel it is appropriate to consider 

whether a change in the volatility of the test fuel is warranted, typically expressed as in 

pounds per square inch (psi) Reid Vapor Pressure (RVP) or dry vapor pressure equivalent 

(DVPE). The Clean Air Act (Section 211(h)(1)) sets a national limit on summertime 

RVP in northern conventional gasoline areas of 9.0 psi to control ozone pollution. 

However, Congress included a waiver allowance (Section 211(h)(4)) granting an 

additional 1 psi RVP to 10% ethanol blends, meaning that E10 could have an RVP up to 

10 psi in these conventional gasoline areas unless specifically prohibited by state or local 

rules. Under Section 211(h)(4), E15 is not covered by the waiver and thus is restricted to 

9 psi nationwide.

The automakers submitted comments that recommended leaving the RVP of 

emissions test fuel at 9 psi on the basis that raising the specification to 10 psi would 

increase the stringency of the proposed evaporative emission standards significantly. We 

agree that the resulting increased vapor generation rates during the refueling test would 

increase emissions (by about 10 percent and during the hot soak, diurnal, canister bleed, 

and running loss tests by as much as 25 percent in total). While the likely increase in 

canister volume in response to higher certification fuel RVP would not be difficult for 

automakers to accommodate in most cases, there are additional uncertainties regarding 

cost and feasibility of strategies for removing the larger vapor loads from the canister 

during vehicle operation (vapor “purging”). Some vehicles have adequate engine 

 

411 More detail on fuel survey data is available in Chapter 3 of the Regulatory Impact Analysis.
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vacuum available to accomplish the increased vapor purge, while others may require new 

or innovative approaches to increase purge volume or efficiency (as discussed in the 

evaporative emissions technology discussion in Section IV.C.3). 

Several other commenters, such as NGOs and environmental groups, supported 

setting certification gasoline RVP to 10 psi to be representative of the worst-case 

volatility vehicles may see in the market, making the test procedure more stringent than 

in the proposed program and further reducing evaporative emissions. 

Raising the certification test fuel RVP to 10 psi would also impact the 

equivalency of CARB and EPA hot soak plus diurnal evaporative emission test 

procedures. (California requires the use of 7 psi RVP test fuel, which, in conjunction 

with higher test temperatures, produces equivalent results to the federal test procedures 

using 9 psi fuel.) If we were to adopt 10 psi test fuel, we would likely need to develop 

and adopt new test procedure adjustments in order to maintain the equivalency of CARB 

and EPA evaporative procedures (and allow reciprocal acceptance of test data generated 

under either agency’s program). 

In addition, the 1 psi RVP waiver for E10 does not apply to gasoline with higher 

ethanol levels; for example, under current regulations E15 is subject to an RVP limit of 9 

psi. If EPA had adopted 10 psi test fuel in this rule and if gasoline with higher ethanol 

levels than E10 were to become commonly used nationwide, maintaining alignment with 

in-use fuel could necessitate a change in emissions test fuel back to 9 psi. 

A review of 2011 gasoline batch data submitted to EPA shows that just under half 

of summertime gasoline was conventional gasoline at 10 psi RVP. An additional third 

was RFG at approximately 7 psi RVP, with the remainder having intermediate RVPs 

under local volatility control programs. A volume-weighted average of these data is 

approximately 8.7 psi RVP. Thus, an emissions test gasoline volatility at 9 psi aligns 

well with the average nationwide in-use RVP today. In addition, virtually all of the areas 

that have elevated summertime ozone levels where excess evaporative VOC emissions 

would be of greatest concern already control in-use gasoline RVP to levels less than 9 

psi. Furthermore, under section 211(a)(5), governors can request that the 1 psi waiver for 

E10 not apply in their state if it causes an emissions increase that contributes to air 

pollution. Any state exercising this authority would have in-use E10 RVP levels limited 

to 9 psi.

After considering these technical and policy issues in the context of the 

information available and comments received, we conclude that the most appropriate 

approach is to set an RVP of 9 psi for Tier 3 emissions test fuel. 

c. Durability Test Fuel

EPA’s motor vehicle emissions standards typically require a level of performance 

over a specified test procedure, with emissions measured while the engine or the vehicle 
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is operated using the specified test fuel and operated in a specified manner. The test fuel 

specifications typically apply for all emissions testing used to determine compliance with 

the standard, including emissions testing to obtain a certificate of conformity, as well as 

compliance testing for newly produced or in-use engines or vehicles. While this test fuel 

is sometimes referred to as “certification fuel,” the test fuel specifications are not limited 

to certification related emissions testing, but also apply to compliance related emissions 

testing after the certificate of conformity has been issued. The certification process also 

typically involves a process to ensure that the emissions controls system is durable over 

the regulatory useful life of the vehicle or engine. This can involve long-term or 

accelerated aging of a vehicle or engine prior to emissions testing. The fuel used for such 

aging is commonly referred to as service accumulation or durability fuel, and in many

cases is specified as commercial gasoline that will be generally available through retail 

outlets (§86.113-04(a)(3)), or in some cases may be specified as gasoline which contains 

ethanol in, at least, the highest concentration permissible in gasoline under federal law 

and that is commercially available in any state in the United States, such as for durability 

aging of evaporative emissions system (§86.1824-08(f)). EPA is not changing the 

specifications for fuel used during durability related aging that is part of the certification 

process. The regulatory changes in this final rule only apply to the test fuel used during 

emissions testing, both for purposes of certification and for later compliance related 

testing.

We are not changing the exhaust or evaporative durability fuel requirements

outlined in the provisions of §86.113-04(a)(3), except to remove the minimum sulfur 

content (15 ppm) specified at §86.113-04(a)(3)(i). Those provisions require that 

“[u]nless otherwise approved by the Administrator, unleaded gasoline representative of 

commercial gasoline that will be generally available through retail outlets must be used in 

service accumulation.” We expect that manufacturers will use service accumulation fuels 

that are generally representative of the national average in-use fuels (or worst case for 

durability) during the model year which is being certified, including, for example, the 

ethanol content (for exhaust emissions), sulfur level, and fuel additive package. For 

exhaust emission bench aging durability programs as allowed under the provisions of 

§86.1823-08(d) and (e), the bench aging program should be designed using good 

engineering judgment to account for the effects of in-use fuels on exhaust emissions, 

including the effects of future in-use fuels on catalytic converters, oxygen sensors, fuel 

injectors, and other emission-related components. 

For evaporative emissions, durability fuel requirements are the same as for 

exhaust emissions (as outlined above), plus an additional requirement in the provisions of 

§86.1824-08(f), that the service accumulation fuel “contains ethanol in, at least, the 

highest concentration permissible in gasoline under federal law and that is commercially

available in any state in the United States. Unless otherwise approved by the 

Administrator, the manufacturer must determine the appropriate ethanol concentration by

selecting the highest legal concentration commercially available during the calendar year 

before the one in which the manufacturer begins its mileage accumulation.” Thus, we 

expect that E15 service accumulation fuel will be used for whole vehicle evaporative 
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durability programs. Similarly, evaporative bench aging durability programs allowed 

under the provisions of §86.1824-08(d) and (e), should be designed using good 

engineering judgment to account for the durability effects of in-use fuels on evaporative 

emissions, bleed emissions, and leakage emissions. 

2. Other Gasoline Emissions Test Fuel Specifications

Where possible, we are changing test fuel specifications to be consistent with 

CARB’s LEV III gasoline test fuel specifications.412 In addition to the ethanol and 

volatility specifications discussed above, below is an overview of some of the key

changes. Table IV-26 provides a summary of the new test fuel properties. For more 

information on how we arrived at the test fuel property ranges and ASTM test methods, 

refer to Chapter 3 of the RIA.

 Octane - lowering gasoline octane to around 87 (R+M)/2 to be representative 

of in-use fuel, i.e., regular-grade E10 gasoline. Manufacturers can continue to 

use high-octane gasoline for testing of premium-required413 vehicles and 

engines as well as for testing unrelated to exhaust emissions. Historically, the 

high octane rating of test fuel has not had any real emissions implications. 

However, as manufacturers begin introducing new advanced vehicle 

technologies (e.g., turbocharged/downsized), this may no longer be the case. 

For those vehicles where operation on high-octane gasoline is required by the 

manufacturer, we are allowing the manufacturer to test on a fuel with a 

minimum octane rating of 91 (R+M)/2 (in lieu of the 87 (R+M)/2 specified for 

general test fuel). According to the regulations found at §1065.710(d), 

vehicles or engines are considered to require premium fuel if they are 

designed specifically for operation on high-octane fuel and the manufacturer 

requires the use of premium gasoline as part of their warranty as indicated in 

the owner’s manual. Cases where premium gasoline is not required but is 

recommended to improve performance would not qualify as a vehicle or 

engine that requires the use of premium fuel. For qualifying vehicles and 

engines, all emission tests must use the specified high-octane fuel. For 

vehicles and engines certified on high-octane gasoline, all EPA confirmatory

and in-use testing would also be conducted on high-octane gasoline. All other 

test fuel specifications are the same as those described in Table IV-26. 

 Distillation Temperatures - adjusting gasoline distillation temperatures to 

better reflect in-use E10 gasoline. This includes minor T10, T90 and FBP 

adjustments based on AAM fuel surveys and refinery batch data. These data 

show that T50 varies widely in in-use fuel, from around 150°F to 220°F. 

 

412 LEV III test procedures, including a description of test fuel, can be found at 13 CCR 1961.2.

413 Premium-required defined at §1065.710(d).
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Adopting a wide specification range for test fuel may have undesirable effects 

on consistency of results between facilities and over time. Therefore, we have 

chosen a range of 190-210°F to maintain some overlap with CARB’s 

specification of 205-215°F but extending somewhat lower to better capture 

federal in-use fuel. For more information on how we arrived at the distillation 

temperatures in Table IV-26, refer to Chapter 3 of the RIA. 

 Sulfur - lowering the sulfur content of test fuel to 8-11 ppm to be consistent 

with our new Tier 3 gasoline sulfur standards. The 10 ppm annual average 

sulfur standard for in-use gasoline standard is expected to result in two-thirds 

less sulfur nationwide so it is appropriate to lower the gasoline test fuel 

specification in concert.

 Benzene - setting a benzene test fuel specification of 0.5-0.7 volume percent to 

represent in-use fuel under the MSAT2 regulations.414 The MSAT2 standards, 

which took effect January 1, 2011, limit the gasoline pool to 0.62 volume 

percent benzene on average. 

 Total Aromatics - lowering the range of aromatics content in the test fuel to 

better match today’s in-use E10 gasoline, and narrowing the range to limit 

variability of results. Data from recent gasoline batch data as well as AAM 

surveys support a specification of 22-26 volume percent.415 

 Distribution of Aromatics – in addition to total aromatics and benzene, the 

updated test fuel requirements place boundaries on the distribution of 

aromatics by carbon number (i.e., prescribed volume percent ranges for each 

of C7, C8, C9, and C10+ hydrocarbons). There is evidence that the heaviest 

aromatics in gasoline contribute disproportionately to PM emissions, so 

compliance with emission standards should be demonstrated on fuel with a 

composition representative of in-use gasoline. For more information on the 

aromatics specifications, refer to Chapter 3 of the RIA. 

 Olefins - adjusting the olefins specification to a range of 4-10 volume percent 

to better match in-use E10 gasoline. 

 Other Specifications - adding distillation residue, total content of oxygenates 

other than ethanol, copper corrosion, solvent-washed gum, and oxidation 

stability specifications to better control other performance properties of test 

fuel. These specifications are consistent with ASTM’s D4814 gasoline 

specifications and CARB’s LEV III test fuel requirements.

 

414 72 FR 8434 (February 26, 2007).

415 More details on fuel property analysis are available in Chapter 3 of the RIA.
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 Updates to Gasoline Test Methods – updating some of the gasoline test 

methods previously specified in §86.113 with more appropriate, easier to use, 

or more precise test methods for ethanol-blended gasoline. Key changes 

include replacement of ASTM D323 with ASTM D5191 for measuring vapor 

pressure; replacement of ASTM D1319 with ASTM D5769 for measuring 

aromatics and benzene; and replacement of ASTM D1266 with three 

alternative ASTM test methods (D2622, D5453 or D7039) for measuring 

sulfur. 
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Table IV-26. Gasoline Emissions Test Fuel Properties

Property Unit

SPECIFICATION

Reference 

Procedurea

General 

Testing

LowTemperature 

Testing

High Altitude 

Testing

Antiknock Index 

(R+M)/2 - 87.0 - 88.4b 87.0 Minimum

ASTM D2699 and 

D2700

Sensitivity (R-M) - 7.5 Minimum ASTM D2699 and 

D2700

Dry Vapor Pressure 

Equivalent (DVPE)

c,d kPa (psi) 60.0-63.4 

(8.7-9.2)

77.2-81.4

(11.2-11.8)

52.4-55.2 

(7.6-8.0) ASTM D5191

Distillatione

10% evaporated °C (°F) 49-60(120-140)

43-54 

(110-130)

49-60

(120-140)

ASTM D86

50% evaporated °C (°F) 88-99 (190-210)

90% evaporated °C (°F) 157-168 (315-335)

Evaporated final 

boiling point °C (°F) 193-216 (380-420)

Residue milliliter 2.0 Maximum

Total Aromatic 

Hydrocarbons volume % 21.0-25.0

ASTM D5769

C6 Aromatics 

(benzene) volume % 0.5-0.7

C7 Aromatics 

(toluene) volume % 5.2-6.4

C8 Aromatics volume % 5.2-6.4

C9 Aromatics volume % 5.2-6.4

C10+ Aromatics volume % 4.4-5.6

Olefins5 mass % 4.0-10.0 ASTM D6550

Ethanol blended volume % 9.6-10.0 See 

§1065.710(b)(3)

Ethanol confirmatoryfvolume % 9.4-10.2 ASTM D4815 or 

D5599

Total Content of

Oxygenates Other 

than Ethanolf

volume % 0.1 Maximum ASTM D4815 or 

D5599

Sulfur mg/kg 8.0-11.0 ASTM D2622, 

D5453 or D7039

Lead g/liter 0.0026 Maximum ASTM D3237

Phosphorus g/liter 0.0013 Maximum ASTM D3231

Copper Corrosion - No. 1 Maximum ASTM D130

Solvent-Washed Gum 

Content

mg/100 

milliliter 3.0 Maximum ASTM D381

Oxidation Stability minute 1000 Minimum ASTM D525

aASTM procedures are incorporated by reference in §1065.1010. See §1065.701(d) for other allowed 

procedures.

bOctane specifications apply only for testing related to exhaust emissions. For engines or vehicles that require 

the use of premium fuel, as described in paragraph (d) of this section, the adjusted specification for antiknock 

index is a minimum value of 91.0; no maximum value applies. All other specifications apply for this high-
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octane fuel.

cCalculate dry vapor pressure equivalent, DVPE, based on the measured total vapor pressure, pT, using the 

following equation: DVPE (kPa) = 0.956∙pT - 2.39 (or DVPE (psi) = 0.956∙pT – 0.347. DVPE is intended to be 

equivalent to Reid Vapor Pressure using a different test method.

d

Parenthetical values are shown for informational purposes only. 

eThe reference procedure prescribes measurement of olefin concentration in mass %. Multiply this result by 

0.857 and round to the first decimal place to determine the olefin concentration in volume %. 

fThe reference procedure prescribes concentration measurements for ethanol and other oxygenates in mass %. 

Convert results to volume % as specified in Section 14.3 of ASTM D4815.

As mentioned earlier, we will continue to allow manufacturers to test vehicles on 

premium-grade gasoline should the vehicles require it. In addition, since we cannot 

predict all future changes in gasoline vehicle technologies and in-use fuels, we will allow 

vehicle manufacturers to specify an alternative test fuel under certain situations. Under 

this provision, if manufacturers were to design vehicles that required operation on a 

higher octane, higher ethanol content gasoline (e.g., dedicated E30 vehicles or FFVs 

optimized to run on E30 or higher ethanol blends), under 40 CFR 1065.701(c), they can 

petition the Administrator for approval of a higher octane, higher ethanol content test fuel 

if they can demonstrate that such a fuel would be used by the operator and would be 

readily available nationwide, vehicles would not operate appropriately on other available 

fuels, and such a fuel would result in equivalent emissions performance. For vehicles 

certified on high-octane, high-ethanol gasoline, all EPA confirmatory and in-use testing 

would also be conducted on high-octane, high-ethanol gasoline. This could help 

manufacturers who wish to raise compression ratios to improve vehicle efficiency as a 

step toward complying with the 2017 and later light-duty greenhouse gas and CAFE 

standards. This in turn could help provide a market incentive to increase ethanol use 

beyond E10 and enhance the environmental performance of ethanol as a transportation 

fuel by using it to enable more fuel efficient engines. 

We received comments in general support of allowing certification on higher 

octane fuels if the vehicles require it, although some commenters believe that the criteria 

EPA is specifying for such an allowance are too severe. We have considered these 

comments, and as discussed in the Summary and Analysis of Comments document, we 

continue to believe that our approach is appropriate, and we are finalizing these 

provisions as proposed. 

3. Flexible Fuel Vehicle Exhaust Emissions Test Fuel 

We are also finalizing specifications for the fuel used in flexible fuel vehicles 

(FFV) exhaust emissions testing including certification testing. EPA is establishing 

specifications for FFV test fuel to resolve confusion and inconsistency among FFV 

manufacturers in carrying out their certification and other testing requirements and to 

ensure that FFV emissions are appropriately controlled over the range of in-use fuels. 

The FFV exhaust emissions test fuel specifications will phase in on the same schedule as 

the E10 standard gasoline test fuel specifications for light- and heavy-duty gasoline 

vehicles (described in Section IV.F.4). These FFV exhaust emissions test fuel 
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specifications may be used voluntarily prior to when they are required to be used. The 

base fuel stock used to formulate FFV exhaust emissions test fuel must comply with the 

specifications finalized today for the standard E10 emissions test fuel as described in 

preamble Sections IV.F.1 and 2. This practice avoids the need to specify the ranges for a 

number of fuel parameters as we have done for gasoline test fuel in Table IV-26 and 

helps to minimize the number of test fuels that a vehicle manufacturer must store. 

Denatured fuel ethanol (DFE) that meets the specifications discussed in preamble Section 

V.G. must be blended into this base fuel stock to attain an ethanol content of 80 to 83 

volume percent in the finished test fuel. Commercial grade normal butane can be added

as a volatility trimmer to meet a 6.0 to 6.5 psi RVP specification for the finished test 

fuel.416

As an alternative to the use of DFE to manufacture FFV test fuel, neat 

(undenatured) fuel grade ethanol can be used. As an alternative to using a finished E10

standard gasoline test fuel in the manufacture of FFV test fuel, the gasoline blendstock 

used by the fuel provider to produce a compliant E10 test fuel can also be used to 

manufacture the FFV test fuel. This would allow ethanol to be blended only once to

produce FFV test fuel. In such cases, a sample of the subject gasoline blendstock must be 

tested after the addition of ethanol to produce a finished standard E10 gasoline test fuel to 

demonstrate that the blend meets all of the requirements for standard gasoline test fuel 

described in Section IV.F. 

The public comments were supportive of EPA establishing specifications for FFV 

exhaust emissions test fuel. However, some commenters stated that the ethanol content 

and RVP specifications for FFV exhaust emissions test fuel should be based on typical 

values for in-use E85.417 Automobile manufacturers commented that EPA should wait to 

finalize FFV test fuel specifications until a review of in-use E51-83 fuel quality can be 

completed in later 2013. They stated that this would allow the FFV test fuel 

specifications to be representative of the change to in-use “E85” composition since 

ASTM reduced the minimum ethanol concentration from 68 to 51 volume percent.

Substantial publicly available literature exists to demonstrate that the ethanol 

content of fuel used in FFVs has a significant effect on vehicle emissions. The effect of 

ethanol content on FFV emissions becomes more pronounced with increasing ethanol 

concentration. The current ASTM specification for E85 provides that the ethanol content 

 

416 The specifications for commercial grade butane are contained in 40 CFR 80.82.

417 The term “E85” has historically been used to describe an ethanol blend for use in FFVs with a maximum 

ethanol content of 83 volume percent and satisfying other fuel parameter specifications established by 

ASTM International. ASTM D5798-13, “Standard Specification for Ethanol Fuel Blends for Flexible-Fuel 

Automotive Spark-Ignition Engines”. 
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of E85 may vary from 51 to 83 volume percent depending on climactic conditions. 418 

Consistent with our long standing policy regarding the exhaust emissions testing of 

FFVs, we continue to believe that FFVs must comply with all emissions control 

requirements while using any fuel that they have the potential to operate on in-use. This 

ensures vehicles are designed and calibrated for emissions performance across the full 

range of potential in-use fuel formulations. FFVs are required to have exhaust emissions 

certification testing conducted using both E10 and FFV exhaust emissions test fuel to 

account for the effect on emissions of the full range of potential ethanol blend 

formulations. To ensure that FFV certification testing adequately accounts for in-use 

emissions performance, we are finalizing the ethanol content of FFV exhaust emissions 

test fuel at 81-83 volume percent as proposed. Exhaust emissions testing conducted 

using a fuel containing 81-83 volume percent ethanol will provide results that represent 

the effect of ethanol on FFV emissions performance when this effect is most pronounced. 

The complimentary emissions certification testing required for FFVs on E10 will ensure 

that the effect on FFV emissions from the full range of potential in-use ethanol 

concentrations is represented. Given the need to ensure that FFV emissions certification 

testing is representative of the full range of potential in-use ethanol blends, it would be 

inappropriate to set the required ethanol concentration for FFV emissions test fuel based 

on typical in-use levels as suggested by some of the commenters.

Similarly, the RVP of FFV exhaust emissions test fuel must assure emissions 

performance over the range of in-use fuels. When ethanol and gasoline are blended to 

produce high level ethanol blends, the RVP can be and often is very low. As a result, 

ASTM instituted a minimum RVP for E51-83 of 5.5 psi. Given that low volatility fuels 

can make the control of cold start emissions more challenging, we are finalizing the RVP 

of FFV exhaust emissions test to be near the minimum RVP that will be encountered inuse. The 6.0 to 6.5 RVP specification finalized today will help to ensure that FFVs are 

designed and calibrated to maintain their exhaust emissions performance across the range 

of in-use fuels. 

The levels of other fuel parameters for in-use E51-83 are determined by the levels 

of these parameters present in the gasoline blendstock used as diluted by the addition of 

ethanol. Therefore, we believe that requiring that the levels of these other fuel 

parameters present in FFV exhaust emissions test fuel be determined by the dilution of 

the levels present in standard gasoline emissions test fuel appropriately reflects their 

potential effect on emissions performance. Given the considerations discussed above in 

determining the FFV exhaust emissions test fuel specifications finalized today, we do not 

believe that there would be a substantial benefit in waiting for the completion of the E51-

83 fuel quality survey currently underway to finalize FFV test fuel specifications. 

 

418 ASTM International D5798-13, “Standard Specification for Ethanol Fuel Blends for Flexible-Fuel 

Automotive Spark-Ignition Engines”. 
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As discussed in preamble Section V.H., the Agency is also considering finalizing 

the in-use fuel quality standards for higher level ethanol blends on which we sought 

comment in the NPRM. These standards included an in-use RVP standard of 9.0 psi 

matching that of conventional gasoline. They also contained provisions to allow the 

production of high-level ethanol blends for use in FFVs from natural gasoline and other 

higher volatility components. Were we to finalize these in-use standards, we would also 

consider raising the RVP for the FFV exhaust emissions test fuel.

We are revising the definition of “alcohol” in 40 CFR part 600 to align with the 

change in the ASTM specification for in-use fuels. Under the revised regulation, we 

consider an alcohol-fueled vehicle to be one that is designed to operate exclusively on a 

fuel containing 51 percent or more ethanol or other alcohol by volume. This is not 

intended to change the applicability, procedures, or requirements for the fuel economy

provisions in 40 CFR part 600.

4. Implementation Schedule 

As described earlier in this Section IV, we are establishing Tier 3 exhaust and 

evaporative emission standards. The changes in the specifications for test fuel apply to 

vehicles certified to these new standards. The program is designed to transition to the 

new test fuel during the first few years as the Tier 3 standards are phasing in. Testing 

requirement with the new Tier 3 test fuel starts with light-duty vehicles certified to Tier 3 

bin standards at or below Bin 70, and heavy-duty vehicles certified to Tier 3 bin 

standards at or below Bin 250 (for Class 2b) and Bin 400 (for Class 3). For light-duty

vehicles, Table IV-27 below describes the implementation schedule of the new Tier 3 

gasoline test fuels for each of the program elements in addition to the all the gasoline test 

fuel options available during the transition period. Table IV-3 below similarly describes 

the heavy-duty gasoline vehicle test fuel implementation schedule and gasoline test fuel 

options. The new Tier 3 PM requirements for both light-duty vehicles and heavy duty 

vehicles which phase-in independent of other vehicle exhaust emission requirements 

must be met using the certification test fuel for meeting the NMOG+NOX standards. 

Starting with model years 2020 for light-duty and 2022 for heavy-duty, all 

manufacturers will use the new test fuel for all exhaust emission testing (with the 

exception of small volume manufacturers and small businesses, which can delay using 

the new test fuel for all vehicles until model year 2022). Manufacturers also need to 

comply with cold temperature CO and NMHC standards using the new test fuel for any 

models that use the new test fuel for meeting the light-duty Tier 3 exhaust emission 

standards as indicated in the tables below. These same tests will also provide the basis 

for meeting GHG requirements under 40 CFR part 86 and fuel economy requirements 

under 40 CFR part 600, as described in the following section. 
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Table IV-27. Exhaust Emissions Gasoline Test Fuels for LDVs, LDTs, and MDPVs

Emission Compliance 

Program

Test purpose: 

demonstration of 

compliance to the 

emissions 

standards: 

Test Cycles

FTP City/ HWFE/SFTP Cold CO 

and 

NMHC

High 

Altitude

Tier 2 Certification (1)(2)(3)(4) (1) (1)

Confirmatory and 

In-use

Certification fuel 

and/or (1)*

(1) (1)

Tier 3 Early Certification (1)**(2)***(3)(4) (1)**(3) (1)**(3)

2015 to 2017 Confirmatory and 

In-use 

Certification fuel (1)**(3) (1)**(3)

Tier 3 phase-in Certification (1)**(2)***(3)(4) (1)**(3) (1)**(3)

2017 to 2019 Confirmatory and 

In-use 

Certification fuel (1)**(3) (1)**(3)

Tier 3 complete Certification (3)(4) (3) (3)

2020+ Confirmatory and 

In-use

Certification fuel 

and/or (3)*

(3) (3)

Fuels: (1) Tier 2 (2) LEV II (3) Tier 3 E10 (4) LEV III E10

*EPA accepts the use of California certification fuels (or Tier 3 E10 for Tier 2 

certification) but manufacturer must comply on the program specific Federal fuel. EPA 

may perform or require manufacturer testing on the Federal fuel. 

**Fuel (1) only allowed for Bins 160, 125, 110, 85.

*** Fuel (2) only allowed for carryover SULEV 150k exhaust. 

Table IV-28. Exhaust Emissions Gasoline Test Fuels for Heavy Duty Vehicles

Emission Compliance 

Program

Test purpose: 

demonstration of 

compliance to the 

emissions 

standards: 

Test Cycles

FTP City/ HWFE/SFTP High 

Altitude

Pre-Tier 3 Certification (1)(2)(3)(4) (1)
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Confirmatory and 

In-use

Certification fuel 

and/or (1)*

(1)

Tier 3 Early Certification (1)** (3)(4) (1)**(3)

2016 to 2017 Confirmatory and 

In-use 

Certification fuel (1)**(3)

Tier 3 phase-in Certification (1)** (3)(4) (1)**(3)

2018 to 2021 Confirmatory and 

In-use 

Certification fuel (1)**(3)

Tier 3 complete Certification (3)(4) (3)

2022+ Confirmatory and 

In-use

Certification fuel 

and/or (3)*

(3)

Fuels: (1) Tier 2 (2) LEV II (3) Tier 3 E10 (4) LEV III E10

*EPA accepts the use of California certification fuels (or Tier 3 E10 for Tier 2 

certification) but manufacturer must comply on the program specific Federal fuel. EPA 

may perform or require manufacturer testing on the Federal fuel. 

**Fuel (1) only allowed for Bins 340, 395, 570, 630.

Additionally, heavy-duty gasoline engines (HDGEs) not subject to new Tier 3 

exhaust emission standards (those certified for exhaust emissions using an engine 

dynamometer) are required to be certified on Tier 3 fuel by MY 2022. Further discussion 

can be found in Section IV.C.4.c. 

For evaporative emission testing, manufacturers will need to use the new test fuel 

for any models that are to be certified to the Tier 3 evaporative emission standards. To 

the extent that these models are different than those used for exhaust emission testing 

with the new test fuel, manufacturers will need to do additional testing to demonstrate 

compliance with all applicable standards. They may alternatively use the new test fuel 

earlier than the regulations specify to avoid additional testing. We further require that 

manufacturers submit certification data based on the new test fuel to demonstrate 

compliance with refueling emission standards for any vehicles that are certified to the 

Tier 3 evaporative emission standards.

5. Implications of Emission Test Fuel Changes on CAFE Standards, GHG 

Standards, and Fuel Economy Labels 

a. Test Fuel

Under regulations in 40 CFR part 600, vehicles use the same test fuel in emission 

testing conducted for CAFE standards, greenhouse gas (GHG) emissions, and the fuel 

economy label as that used for emission testing for criteria pollutants. This includes the 

test fuel used for testing on all five cycles (FTP, highway fuel economy test (HFET), 
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US06, SC03, and Cold FTP). In the Tier 3 NPRM, EPA proposed a change in emissions 

test fuel used to determine compliance with criteria pollutant standards and this test fuel 

change would also apply to CAFE and GHG standards and the fuel economy label such 

that a common test fuel under 40 CFR part 600 was retained. At the same time, EPA 

indicated its commitment to the principle that the change in test fuel would not affect the 

stringency of the CAFE or GHG standards and that the labeling calculations would be 

updated in a future action to reflect the change in test fuel properties.

The NPRM indicated that more data and time were needed to assess the effects on 

stringency and implementation of these programs. While EPA’s initial review of 

available data suggested that the change in test fuel would not impact the GHG standards, 

more time and data were needed to confirm this initial view regarding the GHG standards 

and to determine what adjustments if any would need to be made to the CAFE program 

and fuel economy label calculation procedures to account for the change in test fuel. 

EPA indicated we would defer action on appropriate adjustments, if any, for the GHG 

and CAFE programs until data were available to assess how the difference in the fuel 

properties (Tier 3 fuel compared to Tier 2 fuel) would impact the stringency of the CAFE 

and GHG standards for Tier 3 technology vehicles and the calculations for the fuel 

economy label. EPA indicated that any adjustments or changes in the regulatory text 

would be done through a future action.

Manufacturers commented that EPA should take action on the necessary

adjustments to compliance calculations as part of the Tier 3 final rule. The 

methodologies for addressing some elements of the changes in fuel properties such as the 

difference in energy density are already addressed in the regulation. One key element, 

the “R” factor found in the equation of 40 CFR 600.113-12(h)(1) is intended to capture 

inefficiencies and differences in how vehicles respond to changes in the energy content of 

the fuel. This factor is empirically based, developed using vehicle test data. This value is 

presently set at 0.6 and is shown in the denominator of the aforementioned equation. 

While there has been some data evaluated to assess the impact of changing the emission 

test fuel on the “R” factor, EPA did not propose a value in the NPRM and specifically 

stated that we would continue to investigate this issue and if necessary address it as part 

of a future action, as opposed to changing it in the Tier 3 final rule. Furthermore, as 

discussed above, there is a need for more data to fully understand how other changes in 

certification fuel for Tier 3, such as the octane specification, may affect the stringency of 

the CAFE and GHG standards which were based on Tier 2 emission fuel, as well as any 

implications for the fuel economy label. These potential effects are best understood using 

emission data generated on Tier 3/LEV III vehicles tested on both Tier 3 and Tier 2 test 

fuel.
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In addition, the manufacturers commented that even with the use of “analytically

derived data” as permitted under current EPA regulations and guidance419, EPA should 

finalize an appropriate test procedure adjustment in the Tier 3 rulemaking, including 

adoption of an “R” factor of 1.0, and should allow manufacturers the option of using Tier 

2 fuel for CAFE, GHG, and fuel economy labeling at least through MY2019 to provide 

time for adjusting to the new test fuel. 

In the NPRM, EPA indicated that we would not be changing the “R” factor or 

implementing other adjustments or changes in the regulatory text in the FRM. In followup meetings with the manufacturers, we expressed a willingness to consider permitting 

GHG and CAFE to continue on Tier 2 fuel until the future rulemaking action to address 

the “R” factor and other potential changes was complete and in effect. The 

manufacturers responded that under this approach the existing regulations would require 

a significant amount of additional emission testing for any model certified to the Tier 

3/LEVIII exhaust emission standards before the future rulemaking is completed and in 

effect.420 This is because Tier 3 test fuels would be used in emission data vehicles 

(EDVs) evaluated for compliance with Tier 3 criteria pollutant standards, but these same 

EDVs would also have to be tested on Tier 2 fuel for GHG, fuel economy label, and 

CAFE program data purposes. Also, while Tier 2 fuel would apply to EDVs and fuel 

economy data vehicles (FEDVs) evaluated for fuel economy label, CAFE program data 

values, and compliance with GHG standards, these same FEDVs would have to be 

retested on Tier 3 fuel to show compliance with the Tier 3 criteria pollutant standards. 

This additional testing would also extend to in-use verification program (IUVP) testing 

under 40 CFR 86.1845 through 86.1853.

In response to the concerns expressed by the manufacturers, EPA has identified 

five interim changes to existing regulations to both clarify testing requirements and to 

provide the manufacturers a reasonable opportunity to continue to test for CAFE, GHG, 

and labeling purposes on Tier 2 test fuels for each EDV and FEDV until such time as 

EPA determines appropriate adjustments, if any, related to a change to Tier 3 test fuels. 

EPA believes these changes can be implemented without impacting the integrity of the 

testing conducted for the criteria pollutant, CAFE, and GHG standards or values 

generated for determination of fuel economy labels. It is very important to note that the 

emission test data generated by these early Tier 3/LEVIII vehicles covering both Tier 2 

and Tier 3 test fuel will provide data needed to assess the “R” value and the impact of the 

fuel change on the stringency of the CAFE and GHG standards, and the calculations for 

the fuel economy labeling program. These data will be instrumental in developing any 

appropriate adjustments to maintain equivalent stringency for the CAFE and GHG 

standards and to update the fuel economy labeling calculations, as needed. At the present 

time, EPA expects to have the needed data in early to mid 2015 and will then be in a 

 

419 See 40 CFR §600.006-08(e) and EPA guidance letter CD 12-03, February 27, 2012 and CCD-04-06, 

March 11, 2004, available at http://iaspub.epa.gov/otaqpub/. 

420 This could start as early as the 2015 MY when the LEV III program begins to phase-in.
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

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position to conduct a thorough assessment of the impacts of different emission test fuels 

on Tier 3/LEV III vehicles and develop any appropriate adjustments and changes, in 

consultation and coordination with NHTSA. 

These interim changes which are presented below and shown in Table IV-29, 

apply only to vehicles certified to the Tier 3 and/or LEV III exhaust emission standards in 

the model years before the future action mentioned above takes effect. These are 

reflected in 40 CFR 80.600.117.

1. For any given EDV or FEDV, our regulations will require that testing related 

to CAFE and GHG standards and the fuel economy label must still be done on Tier 2 fuel 

even if criteria pollutant testing is done on Tier 3 or LEV III fuel. The “R” value used in 

the fuel economy equation would remain at 0.6 until any change is made in a future 

rulemaking.

2. The requirement continues that FEDVs are expected to meet the criteria 

pollutant emission standards. As a flexibility, rather than requiring FEDVs to retest on 

Tier 3 fuel to show that they pass the criteria pollutant emission standards, we are 

providing in the regulations that FEDVs may meet these standards using Tier 2 fuel on 

each of the five cycles (as applicable) or be subject to retesting and passing on Tier 3 fuel 

if they do not meet requirements on Tier 2 fuel or otherwise do not comply with 40 CFR 

86.1835-01(b) and 40 CFR 600.008(b). In these circumstances, assuming a retested 

vehicle meets criteria pollutant standards on Tier 3 fuel, the emissions results on the Tier 

2 fuel will still be used for CAFE, GHG, and fuel economy labeling purposes. Retesting 

on Tier 3 fuel is only required for those cycles where the FEDV did not meet the criteria 

pollutant standards on Tier 2 fuel.

3. As a flexibility, if EDV testing is conducted on Tier 3/LEV III fuel for criteria 

pollutants (all 5 cycles), then we are requiring the EDV testing to be conducted on Tier 2 

fuel for only 2 cycles (FTP and HFET) for GHG and CAFE purposes. These emission 

results on Tier 2 fuel are expected to meet the Tier 3 criteria pollutant standards. Our 

regulations then require manufacturers to use these EDV Tier 2 fuel test results (FTP and 

HFET) for the CAFE, and GHG standards. The EDV Tier 2 fuel test results (FTP and 

HFET) would also be used for fuel economy label calculations except in rare cases where 

the EDV does not pass the litmus test or if the manufacturer voluntarily elects to use the 

vehicle specific 5-cycle method to determine fuel economy label values. In those two 

cases, the EDV would need to be tested on Tier 2 test fuel on each of the five cycles.

4. As a flexibility, during the interim model years, manufacturers may use either 

Tier 2 or Tier 3/LEVIII test fuel emission results to conduct the litmus evaluations for 

fuel economy labeling under 40 CFR 600.115-11. All emission results for the five tests 

involved used must be from the same test fuel. EPA believes this is appropriate since the 

litmus evaluation is based on a comparison of the percent differences of 2 and 5 cycle 

values rather than absolute differences in the values. If a manufacturer chooses to conduct 

the litmus evaluation using LEVIII fuel, the cold FTP test must still use Tier 3 fuel. In 
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the situation where the manufacturer uses Tier 3/LEV III test fuel for the litmus test the 

R-factor will be 0.6. EPA will provide guidance on determining the values for the other 

fuel quality parameters needed for the fuel economy calculations when Tier 3/LEVIII 

fuel is used. 

5. Exhaust emission testing for IUVP for GHGs shall be conducted using the 

same test fuel as used for criteria pollutant certification, unless the manufacturer 

uniformly elects to conduct its IUVP GHG testing on Tier 2 fuel. This relieves the need 

to conduct IUVP testing for criteria pollutants on Tier 3 fuel and GHG testing on Tier 2 

fuel. EPA believes this is an acceptable interim regulatory flexibility, since the IUVP 

testing for GHGs does not involve the IUCP provisions of 40 CFR 86.1846-01.

Table IV-29: Interim Testing Requirements for EDVs and FEDVs on Tier 3 and 

Tier 2 Test Fuel

Criteria 

Pollutant 

(EDVs)

GHG/Label/CAFE Litmus IUVP

(EDVs and FEDVs) (Tier 2 

fuel)

Calculation

Tests/Cycles 5-cycle 5-

cycle

2- cycle 

(CAFE/GHG/label)

5-cycle Criteria 

Pollutant

GHG*

(label)

Test fuel 

requirements

Tier 3 

fuel or 

other 

transition 

option**

Tier 2 

fuel

Tier 

2 fuel

Tier 3 fuel Tier 2 or 

Tier 3 fuel

Tier 3 

fuel

Tier 2 

fuel

FTP X X X Show 

criteria 

pollutant 

standards 

are met 

using Tier 

2 fuel or 

must retest 

on Tier 3 

fuel

Use 5-

cycle Tier 

3 fuel or 

Tier 2 fuel 

test results

X X

HFET X X X X X

US06 X X X

SC03 X X

Cold FTP X X

* Manufacturer may uniformly elect to use Tier 2 fuel results to meet the IUVP GHG requirements or rely on Tier 3 results.

** California Phase 2 fuel is only permitted for GHG/Label/CAFE and Litmus assessments for vehicles certified for criteria 

pollutants in the Tier 3 program using carryover data from CARB LEV II certifications such as SULEVs and PZEVs.
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Manufacturers may use LEVIII fuel (California Phase 3) in lieu of Tier 3 fuel, but 

any cold FTP testing must be done using Tier 3 Cold FTP fuel. LEV III fuel is 7 RVP 

E10, Tier 3 fuel is 9 RVP E10, and Tier 2 fuel is 9 RVP E0. 

Manufacturers have presented two points of view with regard to when the 

potential new requirements (including a revised “R” factor and other possible test 

procedure changes/adjustments related to CAFE, GHG, and fuel economy labeling) 

should take effect once the future rulemaking action mentioned above is complete. Some 

have stated that use of the new provisions should be available for use as soon as possible 

after the rule is completed. This would minimize the need for any future duplicate testing 

and put manufacturers on course for fully aligning with the new requirements quickly. 

Others have asked that there be lead time provided before the application of the new 

requirements becomes mandatory. The manufacturers have expressed concern that the 

use of the new requirements more quickly by one manufacturer versus another could 

create a competitive imbalance. At the same time, manufacturers do not necessarily want 

to be forced to certify all products to the new requirements by a cut-off date (e.g., 2020 

model year) without EPA consideration of phase-in or phase-out provisions and data 

carryover. 

EPA understands the manufacturers’ various issues and concerns in this area. 

Based on the information available at this time, EPA is expecting to allow the optional 

use of any future adjustments for compliance calculation and labeling purposes as soon as 

the future rule mentioned above becomes effective. Furthermore, we expect that the 

mandatory use of any such new adjustments with all Tier 3 certifications would be 

required for the 2020 MY. These initial timing projections are subject to revision based 

on timing of the completion of the future action and the data and record developed in that 

future rulemaking. 

b. Useful Life for GHG Standards

As stated above, EPA is committed to retaining equivalent stringency for GHG 

emissions compliance beginning in MY 2017. We need more emissions test data to 

better understand the GHG emission impacts of Tier 3 fuel in Tier 3 technology vehicles. 

However, we believe that certifying a vehicle to a longer useful life for any emission 

constituent would have only a beneficial effect on emissions. To address potential 

concerns about changes in the stringency of the GHG standards resulting from a longer 

useful life, we are not requiring a longer useful life for GHG emission standards, 

although manufacturers can optionally certify GHG emissions to a 150,000 mile, 15 year 

useful life.

6. Consideration of Test Fuel for Nonroad Engines and Highway Motorcycles

As described earlier in Section IV.F., we are adopting new specifications for the 

gasoline emissions test fuel used for testing highway vehicles subject to the Tier 3 

standards. Earlier in the development of this rulemaking, EPA also considered changing 
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the test fuel specifications for other categories of engines, vehicles, equipment, and fuel 

system components that use gasoline. These include a wide range of applications, 

including small nonroad engines used in lawn and garden applications, recreational 

vehicles such as ATVs and snowmobiles, recreational marine applications, and highway

motorcycles. While engines in some of these categories employ advanced technologies 

similar to light-duty vehicles and trucks, the vast majority of these engines employ much 

simpler designs, with many of the engines being carbureted with no electronic controls. 

Because of the lower level of technology, emissions from these engines are potentially

much more sensitive to changes in fuel quality.

EPA is not applying the new emissions test fuel specifications to these other 

categories of engines, vehicles, equipment, and fuel system components. In discussing 

the potential change in test fuel specifications with the large number of businesses

potentially impacted by such a change, many companies supported such a change. 

However, a number of manufacturers raised concerns about the level of ethanol in the 

new fuel, the cost of recertifying emission families on the new fuel, the impact on 

nationwide product offerings, and the cost impact of complying with the existing 

standards on the new test fuel. EPA believes it is important that the test fuel for these 

other categories reflect real-world fuel qualities but has elected to defer moving forward

now pending additional analysis of the impacts of changing the test fuel specifications for 

the wide range of engines, vehicles, equipment and fuel system components that could be 

impacted. These impacts include the impact on the emissions standards, as well as the 

other issues raised by the manufacturers. EPA plans to explore such a change in a 

separate future action. 

While we are not changing the test fuel specifications for these other types of 

vehicles and engines, we are updating the reference standards associated with specific 

parameters and making minor adjustments to calculation methods. For certified engines 

and vehicles that have already been using the test fuel specified in §1065.710, we are 

clarifying that the RVP is calculated using the same equation described above for the new 

fuel specified for Tier 3 vehicles. We are also taking the opportunity to align and update 

test methods for the various gasoline test fuels in 40 CFR part 86. Specifically, we are 

revising §§86.113 and 86.213 to (1) use both ASTM D2699 and ASTM D2700 for octane 

measurements involving both research and motor octane specifications (including octane 

sensitivity), (2) use ASTM D2622 for all sulfur measurements, which is widely used and 

provides superior results compared with the methods that have been referenced in the 

regulations, (3) use ASTM D5191 for measuring fuel volatility, including the calculation 

described above. We are also updating the regulations to reference a newer version of the 

following currently referenced procedures: ASTM D86, ASTM D1319 ASTM D2699, 

ASTM D3231, and ASTM D3237. All these changes and updates align with fuel 

specifications in 40 CFR part 1065.
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7. CNG and LPG Emissions Test Fuel Specifications

There are currently no sulfur specifications for the test fuel used for certifying 

natural gas (CNG) vehicles. There is also no sulfur specification in 86.113 for the test 

fuel used for certifying liquefied petroleum gas (LPG) light duty vehicles. The LPG 

certification test fuel for heavy-duty highway engines and for nonroad engines in 

1065.720 includes an 80 ppm maximum sulfur specification. We requested comment on 

the appropriateness of changing 86.113 to reference 40 CFR part 1065 for all natural gas 

and LPG test fuels. We further requested comment on amending these specifications to 

better reflect in-use fuel characteristics, and in particular on the appropriateness of 

aligning the sulfur specifications with those that apply for gasoline test fuel. We noted 

that changing the sulfur specifications would depend on establishing that the new 

specification is consistent with the range of properties expected from in-use fuels.

The Alliance of Automobile Manufacturers (the Alliance) stated that EPA should 

adopt a 10 ppm maximum sulfur specification for CNG and LPG vehicle certification test 

fuels. They also stated that §86.113 should reference part 1065 for CNG and LPG test 

fuels (for light and heavy duty vehicles). The American Petroleum Institute (API), the 

Association of Fuel and Petrochemical Manufacturers (AFPM), and several individual 

refiners stated that EPA should not establish new sulfur standards for CNG and LPG 

vehicle certification test fuels until additional data are available on the sulfur content of 

in-use CNG/LPG fuels. The National Propane Gas Association (NPGA) stated that they

are opposed to a change in the sulfur specifications for LPG vehicle certification test 

fuels given that they are unaware of any issue that would warrant such a change. 

As discussed in Section V.J. of today’s preamble, additional time is needed for 

EPA to work with industry to collect data on current CNG/LPG sulfur content, to 

determine whether additional control of in-use CNG/LPG sulfur content is needed, and to 

evaluate the feasibility and costs associated with potential additional sulfur controls. 

Therefore, we are deferring finalizing in-use quality and certification test fuel 

specifications for CNG and LPG at this time.

G. Small Business Provisions

We are adopting special flexibility provisions for small businesses that are subject 

to the Tier 3 emissions standards. Such businesses are typically vehicle manufacturers, 

independent commercial importers (ICIs), or alternative fuel vehicle converters. We are 

also providing Tier 3 flexibility to companies that, though they may not meet the 

eligibility requirements for small businesses, sell less than 5,000 vehicles per year in the 

United States, and thus qualify as small volume manufacturers (SVMs). These 

companies and small businesses typically face similar challenges in implementing new 

EPA vehicle standards.

As in previous vehicle emissions rulemakings in which we have provided such 

flexibilities, our reason for doing so is that these entities generally have more 
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implementation difficulty than larger companies. Small companies generally have more 

limited resources to carry out necessary research and development; they can be a lower 

priority for emission control technology suppliers than larger companies; they have lower 

vehicle production volumes over which to spread compliance costs; and they have a 

limited diversity of product lines, which limits their ability to take advantage of the 

phase-in and averaging provisions that are major elements of the Tier 3 program.

We proposed small business provisions largely based on the recommendations of 

the Small Business Advocacy Review (SBAR) Panel, described in Section XIII.C of the 

Notice of Proposed Rulemaking (NPRM). We proposed provisions for additional lead 

time, reduced testing requirements, and opportunities for hardship relief to help small 

entities to leverage technological developments by others and to spread the availability of 

needed engineering, supplier, and capital resources. Based on the comments we received, 

we have improved on the proposed provisions in the final rule as described in detail 

below.

1. Lead Time and Relaxed Interim Standards

We proposed that small businesses and SVMs be allowed to postpone compliance 

with the standards and other Tier 3 requirements, including use of the new certification 

test fuel, until model year (MY) 2022. For MY 2022 and later, they would be subject to 

the same Tier 3 requirements as other manufacturers, including the declining fleet 

average NMOG+NOx standards and the fully phased in 30 mg/mi FTP standard for MYs 

2025 and later. We requested comment on adopting relaxed FTP NMOG+NOx standards 

for small companies in the light-duty market segment, noting that LEV III provides lightduty SVMs with relaxed FTP NMOG+NOx standards of 125 and 70 mg/mi in MYs 2022 

and 2025, respectively.

We did not receive comments from non-SVM small businesses subject to the Tier 

3 vehicle standards about our proposed small entity phase-in provisions. However, we 

received comments from SVMs, as well as the Alliance of Automobile Manufacturers 

and the Association of Global Automakers, arguing that the proposed phase-in did not 

provide adequate lead time relief for SVMs, and that the long-term Tier 3 standards for 

light-duty vehicles are not technologically feasible for SVMs. They highlighted the 

ability of large manufacturers to offset high emissions from high-performance, luxury

models by averaging with their low-emitting models, while competing SVM products 

must be designed to actually achieve low emissions while still meeting customers’ 

performance expectations. Their limited production can also result in emission control 

technology suppliers placing a lower priority on SVM orders than on those of larger, 

high-volume manufacturers. 

Because of these factors, SVMs suggested that their companies meet a slightly

more stringent NMOG+NOX standard (125 mg/mi) than what we proposed for SVMs in 

the early years of the program, and a permanently relaxed standard of 51 mg/mi 

beginning in MY 2022. Ferrari suggested a compliance schedule for SVMs similar to 
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the California LEV III program, with either a permanently relaxed standard (matching the 

California LEV III 70 mg/mi long-term standard) or a delay until MY 2030 to meet the 

primary 30 mg/mi Tier 3 standard (when they suggest that SVMs could potentially

comply). CARB comments supported Tier 3 adoption of its LEV III provisions for 

SVMs, including the long-term 70 mg/mi standard beginning in MY 2025. VNG, a 

natural gas fuel network provider, commented that gaseous-fuel small-volume test groups 

should be given extended phase-in opportunities identical to those proposed for SVMs, 

regardless of company size. As justification, VNG pointed to challenges unique to 

converting vehicles to operate on natural gas: thermal management of direct injection 

fueling and engine oil systems, adaptation of gasoline direct injection (GDI) controls to 

natural gas port fuel injection, and improvement of turbocharger response times. 

After considering the comments, we agree with SVMs that their unique logistical 

and technological challenges, especially in the later years of the primary FTP 

NMOG+NOx standards phase-in schedule, warrant a significant period of relaxed 

standards for these manufacturers. However, we have found no fundamental reason why, 

given sufficient lead time, all manufacturers, regardless of company size and vehicle 

characteristics, will not be able to meet the Tier 3 standards. Thus, we are finalizing an 

optional program for SVMs, available to non-SVM small businesses as well, under which 

they can choose an alternative 3-stage FTP NMOG+NOx fleet average standard phase-in 

schedule: an initial standard of 125 mg/mi for MYs 2017 through 2021, a more stringent 

standard of 51 mg/mi for MYs 2022 through 2027, and the final Tier 3 standard of 30 

mg/mi thereafter. 

Because companies choosing this 3-stage compliance option are certifying to Tier 

3 bin standards in MY 2017, we are requiring that other exhaust emissions standards, 

including SFTP and PM standards, apply for their vehicles as well, to the same degree 

and on the same schedule as for other manufacturers. Application of evaporative 

emissions and onboard diagnostics (OBD) standards, on the other hand, is not affected by 

choice of the 3-stage compliance option for the FTP NMOG+NOx standards, and small 

companies may separately choose to delay compliance with evaporative emissions and 

OBD standards (except as noted in Section IV.G.3) until MY 2022, as proposed. In 

addition, small companies choosing the 3-stage compliance option may delay the longer 

useful life and new test fuel requirements for exhaust emissions standards until MY 2022 

to align these changes with the 3-stage schedule. This option would not preclude use of 

other applicable small entity flexibility provisions discussed in this subsection.

Although we are adopting this revised implementation schedule for SVMs and 

small businesses, we believe the proposed approach of allowing postponement of Tier 3 

compliance until MY 2022 may be useful for small companies needing more lead time to 

begin certifying Tier 3 vehicles. Therefore we are finalizing the proposed approach as an 

additional but separate option for such companies, including SVMs, ICIs, and alternative 

fuel vehicle converters. Furthermore, because the optional 3-stage SVM implementation 

schedule, and the record of comments that prompted it, are specific to the light-duty 

sector, we are not extending it to heavy-duty vehicles and instead are finalizing only the 
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proposed approach of allowing postponement of Tier 3 compliance until MY 2022 for 

any SVMs and small businesses in the heavy-duty sector.

Companies that take advantage of one of the SVM and small business 

implementation schedule provisions in either the light-duty or heavy-duty sector are not 

allowed to generate or use Tier 3 exhaust emissions credits in that sector while or before 

they are subject to significantly less stringent standards than other manufacturers. That 

is, they cannot earn or use Tier 3 exhaust emissions credits before MY 2022 under the 3-

stage light-duty SVM revised implementation schedule, and they also cannot do so before 

MY 2022 if they are using the postponed compliance schedule that we proposed, unless 

they choose to end their use of these SVM implementation options earlier than MY 2022.

We disagree with VNG’s assessment that small-volume test groups of large 

manufacturers should have until 2022 to comply with Tier 3. The technical challenges 

outlined by VNG have to do with converting gasoline vehicles to run reliably and durably 

on natural gas. Although these conversion challenges may be exacerbated for the new 

generation of turbocharged GDI vehicles, we have no evidence or comments from a 

vehicle manufacturer indicating that meeting Tier 3 standards is significantly more 

difficult for natural gas vehicles than for gasoline vehicles. Note that we are providing 

some relief for small volume test groups in the form of assigned deterioration factors 

(discussed below), but not because of feasibility concerns. Rather, we believe that 

assigned deterioration factors provide a sufficient alternative to the extensive process of 

developing a unique factor for each low-volume vehicle model. We find no justification 

to delay compliance with Tier 3 standards for larger manufacturers’ low-volume models 

as requested by VNG.

2. Assigned Deterioration Factors

In Tier 3 as in past programs, manufacturers must demonstrate compliance with 

emissions standards throughout the vehicle’s useful life. This is generally done by testing 

vehicles at low mileage and then applying a deterioration factor to the measured 

emissions levels. The deterioration factors are determined by testing emissions control 

systems before and after an aging process. In the past we have allowed small entities to 

use deterioration factors assigned by EPA instead of performing the extended testing, and 

we proposed to do so again for demonstrating compliance with Tier 3 exhaust and 

evaporative emissions standards. We did not propose specific assigned deterioration 

factors, but noted that the proposed delay in the small entity compliance schedule to MY 

2022 would allow sufficient deterioration data from large manufacturers to accumulate 

for timely development of these factors.

We are adopting the assigned deterioration factor provisions for small businesses 

and SVMs (as well as for small volume test groups), as proposed. Commenters 

expressed support, and asked that the Agency commit itself to keeping these factors up to 

date as durability data accumulates. In response, we can state that we are committed to 

periodically updating and publishing these assigned deterioration factors. Given that 
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SVMs will be allowed to use the revised implementation schedule described above, 

starting in MY 2017, it becomes necessary to consider assigned deterioration factors in 

stages. Because there may not be a sufficient base of accumulated durability data on Tier 

3 vehicles by MY 2017, we expect that the current set of assigned factors based on Tier 2 

vehicles may continue in place for some time, noting that the MY 2017-2021 SVM fleet 

average of 125 mg/mi is not too much different from the average of today’s Tier 2 

vehicle emissions. By MY 2022, when the SVM NMOG+NOx fleet average standard 

drops to 51 mg/mile, we expect to have new assigned factors available. We note that 

small businesses and SVMs may also, with advance EPA approval, use deterioration 

factors developed by another manufacturer (40 CFR 86.1826-01(b)).

3. Reduced Testing Burden and OBD Requirements

Under our existing regulations, manufacturers must perform in-use testing on 

their vehicles and demonstrate that their in-use vehicles comply with the emissions 

standards. These regulations provide for reduced levels of testing for small companies 

with annual sales under 15,000, and for no in-use testing for those with annual sales up to 

5,000. We received no adverse comments on our proposal to continue this approach in 

Tier 3, and are retaining it.

As described in Sections IV.A and IV.B, we are requiring manufacturers to test 

for PM emissions from vehicles of all fuel types, a change from previous practice in 

which non-diesel vehicles could be waived from PM testing. However, we proposed and 

have decided to continue the PM testing waiver in Tier 3 for small businesses and SVMs. 

In lieu of testing, these companies are required to make a statement of compliance with 

the Tier 3 PM standards, and their vehicles are still subject to the standards. We may

however measure PM emissions to determine compliance in EPA confirmatory or in-use 

testing.

We proposed to apply CARB’s OBD requirements to Tier 3 vehicles, except that 

small alternative fuel vehicle converters would be allowed to instead meet our existing 

OBD requirements (40 CFR 86.1806-05). The natural gas fuel network provider VNG 

objected that the proposed exception disadvantages larger vehicle manufacturers and 

should be made equally available to all vehicle manufacturers’ small volume test groups. 

We expect that larger manufacturers wishing to produce alternative fuel vehicles will be 

familiar with CARB’s OBD requirements and well-positioned to implement these 

requirements in Tier 3. We note that larger OEMs themselves did not request to be 

covered by an extension of this provision. 

We are finalizing the exception to the Tier 3 OBD requirements as proposed. 

Note that the optional delay in Tier 3 implementation until MY 2022 that is available to 

small businesses, discussed above, includes a delay in the Tier 3 OBD requirement to 

MY 2022, as proposed, except that vehicles already meeting this requirement in MY 

2017 must continue to do so in subsequent years. We are also adopting this Tier 3 OBD 

delay to MY 2022 for small companies taking advantage of the revised light-duty 3-stage 
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implementation schedule discussed above, even though other Tier 3 requirements start for 

them in MY 2017, in order to avoid overburdening these manufacturers with multiple sets 

of new OBD design constraints.

4. Hardship Relief

We proposed and are adopting provisions for small businesses and SVMs in 

hardship situations to apply for additional time to meet the Tier 3 standards. Such 

appeals will need to include evidence that the noncompliance would occur despite the 

manufacturer's best efforts to comply, and that severe economic hardship would occur if 

the relief is not granted, though the company need not show that its solvency will be in 

jeopardy without the relief. (This showing is required in other EPA programs granting 

hardship relief under 40 CFR 1068.250.) The duration of relief will be established on a 

case-by-case basis for Tier 3 and is not being limited by regulation. Commenters 

supported these proposed provisions, within the context of a revised approach to SVM 

lead time, discussed above.

5. Eligibility for the Flexibilities

As proposed, we are using the federal Small Business Administration (SBA) 

criteria to define small businesses eligible for the special provisions. SBA defines small 

business vehicle manufacturers as those with less than 1,000 employees, and small 

business ICIs and alternative fuel vehicle converters are evaluated using SBA criteria

based on annual revenues. See Section IV.H.3 for a discussion of additional provisions 

that apply specifically to ICIs. Also, as proposed, we are defining SVMs in 40 CFR 

86.1838-01 for purposes of Tier 3 as companies with nationwide annual U.S. sales 

volumes at or below 5,000 vehicles, though the 15,000 vehicle threshold used in Tier 2 

continues to apply in a few regulatory provisions that Tier 3 changes are not impacting. 

Eligibility will be evaluated using an average of 2012-2014 MY sales. For companies 

with no 2012 MY sales, projected sales may be used, but their eligibility will be reevaluated thereafter using a three-year running average.

VNG commented that the proposed 5,000 vehicle threshold could potentially limit 

the ability (or willingness) of natural gas SVMs to scale up production by forcing a 

tradeoff between sales and regulatory burden, pointing also to the fact that 15,000 

vehicles is only 0.1% of annual light-duty vehicle sales. We do not believe that the SVM 

relief provisions are so advantageous as to cause self-limiting of sales, except possibly in 

the unlikely case of a company very near the threshold. Even if this were to happen, 

moving the threshold to 15,000 would not prevent the same dynamic from happening at 

that sales level. Furthermore, our use of a three-year average of sales for determining 

SVM eligibility protects the SVMs from being penalized for having an especially good 

year not reflective of its long-term growth trend. See the MY 2017 and later light-duty 

GHG final rule for a discussion of our basis for adopting the 5,000 vehicle threshold (77 

FR 62793, October 15, 2012).
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We requested comment on extending eligibility for the Tier 3 SVM provisions to 

small manufacturers that are owned by large manufacturers but are able to demonstrate 

that they are operationally independent. We established such a provision in the light-duty 

greenhouse gas (GHG) program, and CARB did so in LEV III. Comments from CARB 

and Ferrari supported this extension. No commenters opposed it; however, Advanced 

Biofuels USA recommended caution to avoid advantaging SVMs capable of leveraging 

parent company resources to drastically increase U.S. market share within 2-3 years. 

Given the establishment of this provision in our GHG program, and the value of this 

extension for harmonization with LEV III, we are adopting this change into Tier 3 using 

the same eligibility criteria as in our GHG program, set forth in 40 CFR 86.1838-01(d). 

We believe these criteria are sufficiently strict and objective to address the concerns 

expressed by Advanced Biofuels USA.

To qualify as SVMs in either the light-duty or heavy-duty Tier 3 programs, the 

company’s total sales of vehicles subject to standards under Part 86 Subpart S count 

toward the vehicle sales limit, including both light- and heavy-duty vehicles. Companies 

so qualified may take advantage of SVM provisions in both sectors.

H. Compliance Provisions

1. Exhaust Emission Test Procedures

We are finalizing most of the amendments we proposed to 40 CFR part 1066 as 

part of the effort to migrate test requirements from 40 CFR part 86. We began this 

process a couple of years ago when we established part 1066, but we applied these test 

procedures only to certain vehicles above 14,000 lbs gross vehicle weight rating 

(GVWR) for the purpose of measuring greenhouse gas emissions (76 FR 57470, 

September 15, 2011). This final rule extends these procedures, with some amendments, 

to vehicles at or below 14,000 lbs GVWR for measurement of both criteria pollutants and 

greenhouse gas emissions. The procedures in part 1066 cover the same requirements that 

have been included in 40 CFR part 86, but include more detailed specifications for how 

to measure exhaust emissions using a chassis dynamometer. They also reference large 

portions of 40 CFR part 1065 to align test specifications that apply equally to enginebased and vehicle-based testing, such as CVS and analyzer specifications, calibrations, 

test fuels, calculations, and definitions of many terms. Overall, the part 1066 procedures 

represent a modernization of the part 86 procedures rather than fundamentally different 

procedures.

Until this rule, testing requirements related to chassis dynamometers have relied 

on a combination of regulatory provisions, EPA guidance documents, and extensive 

learning from industry experience that has led to a good understanding of best practices 

for operating a vehicle in the laboratory to measure emissions. The revisions we are 

finalizing capture this range of material, integrating and organizing these specifications 

and procedures to include a complete set of provisions to ensure that emission 

measurements are accurate and repeatable.
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This final rule includes the following revisions to part 1066:

• Clarification of regulatory requirements.

• Migration of mass-based emission calculations from part 86 to part 1066.

• Introduction of a new NMOG calculation.

• Revision of 40 CFR part 1066, subpart B, to increase the specificity with which 

part 1065 references are made as they pertain to testing equipment, test fluids, test gases, 

and calibration standards.

• Addition of coastdown procedures for light-duty vehicles.

• Reordering of the test sequence with respect to vehicle preparation and running 

a test.

• Specifying part 1065 procedures for PM measurement, including certain 

deviations from part 1065 for chassis testing.

• Insertion of detailed test specifications for vehicles certified under 40 CFR part 

86, subpart S.

• Addition of provisions related to testing with four-wheel drive dynamometers, 

as described below.

• Correction of typographical errors.

We are finalizing the use of part 1065 for PM measurement with slight 

adjustments to the dilution air temperature, minimum dilution ratio, and background 

measurement requirements. By controlling the parameters that affect PM formation 

(dilution air temperature, dilution factor, sample residence time, filter face temperature, 

and filter face velocity), the procedures will reduce lab-to-lab and test-to-test variability.

The regulations being finalized will provide alternative approaches to sample PM 

onto different combinations of filters. One option is to collect a sample for phases 1 and 

2 of the FTP on a single filter, and collect a sample for phases 2 and 3 of the FTP onto a 

second filter. Another option is to collect a sample for phases 1, 2, and 3 on a single 

filter. A final option is to sample PM emissions from two full UDDS cycles; however 

manufacturers choosing this option must still run a separate three-bag test for evaporative 

emission testing. We will continue to allow sampling under the traditional FTP 

methodology of a bag or filter per test phase (3 phases in total) instead of these new 

methods. We are also finalizing new PM sampling and calculation methods as proposed.

We are revising the chassis dynamometer specifications in part 1066 by removing 

the maximum roll diameter and by requiring speed and force measurements at a 
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minimum frequency of 10 hertz (Hz). Some manufacturers may be interested in testing 

with nonstandard dynamometer configurations, such as new flat-track dynamometers or 

old twin-roll dynamometers. We may approve the use of these and other nonstandard 

dynamometer configurations as alternative procedures under 40 CFR 1065.10(c)(7).

We proposed that EPA may test vehicles with the capability of all-wheel drive 

operation with dynamometers operating in either two-wheel drive or four-wheel drive 

mode, regardless of the type of dynamometer that the manufacturer used for certifying 

the vehicle. However, the final regulations specify that we will conduct our testing using 

the same drive mode as the manufacturer. Vehicle manufacturers commented that 

differences in test results between a vehicle tested on a two-wheel drive and a four-wheel 

drive dynamometer might be due to differences in dynamometer characteristics more 

than in vehicle operation. Results of a government-industry study that tested vehicles on 

both two-wheel and four-wheel drive dynamometers indicated fuel economy differences 

in the range of ±4%, although the study was inconclusive with respect to the cause of the 

differences.421 Based on the results of this study, we will continue to test vehicles during 

confirmatory tests using the manufacturer’s dynamometer configuration for that vehicle, 

and that test will be the official certification result. We are, however, finalizing revisions 

to 40 CFR 1066.410(g) to clarify that we may also test the manufacturer’s vehicle in a 

different dynamometer configuration than what was used for certification testing for 

information-gathering purposes. If we decide to perform this testing, we will depend on 

the manufacturer to cooperate in reconfiguring the test vehicle for our testing. We will 

continue to investigate the effects of four-wheel drive dynamometers on emission results 

and will not rule out possible future test procedure changes that might require 

certification of, or allow EPA to perform confirmatory testing on, any vehicle on a fourwheel drive dynamometer.

In their comments to this rulemaking, vehicle manufacturers stressed the 

importance to them that EPA use the same test procedures that they used for their 

certification testing when we perform confirmatory testing on their vehicles. Although 

the manufacturers did not explain the reasons for their comment, we presume that the 

manufacturers’ concern relates to situations where EPA test procedures would lead to 

higher emission levels than those resulting from a slightly different test procedure used 

by a manufacturer. If so, the concern is misplaced. The purpose of EPA’s test procedure 

flexibility provisions is not to allow manufacturers to use test procedures as a tool to 

enable compliance with the standards – in other words, to demonstrate compliance for 

engines that in the absence of the regulatory test procedure flexibility would not meet the 

standard. Rather, the purpose is to reduce the burden of testing. We go through the 

rulemaking process to establish the specified default test procedures as a means of 

creating an objective measure of compliance with emission standards. Where we also 

 

421 “Four Wheel Drive Dynamometer Meeting with the Alliance of Automobile Manufacturers and the 

Global Automakers,” EPA Memo from Chris Laroo, November 13, 2013.
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include alternative procedures, they generally are not intended to change the conclusions 

from the rulemaking related to the stringency of the emission standards, or to lead to a 

different conclusion regarding compliance relative to the specified test procedures. EPA 

has addressed this issue previously for engine testing in §1065.10(a), where we note that 

we condition the allowance to use alternate procedures on the provision that they would 

“not affect your ability to show that your engines comply with the applicable emission 

standards.” We note further that this provision “generally requires emission levels to be 

far enough below the applicable emission standards so that any errors caused by greater 

imprecision or inaccuracy do not affect your ability to state unconditionally that the 

engines meet all applicable emission standards.”

In a related context, §1065.10(c)(1) explains that the intent of the test procedures 

is “to produce emission measurements equivalent to those that would result from 

measuring emissions during in-use operation”. This provision, which also applies for 

vehicle testing, envisions a process in which both the manufacturer and EPA can apply 

their engineering judgment to improve the representativeness of the testing. It would be 

appropriate for a manufacturer to ask EPA to modify our test procedures if the 

manufacturer believed EPA’s test procedures would lead to results that were 

unrepresentative of in-use operation. However, it would not be appropriate to ask us to 

modify our test procedures to make them less representative of in-use operation.

The proposed rule included discussion of SI units as part of emission 

measurement procedures. At this time we are not converting emission standards to SI

units. Note however that like part 86, part 1066 relies extensively on calculations 

involving physical parameters to calculate emission rates and perform various 

calibrations and verifications. As already reflected in part 1066, manufacturers have used 

a variety of units to perform these calculations. We would expect that dynamometers and 

other laboratory equipment are all capable of operating in SI units even if current practice 

in some laboratories is to use other units. Moving toward standardized units for 

calculations will allow us to more carefully and appropriately specify precision values for 

various measured and calculated parameters. This will also simplify calculations, 

facilitate review of results from different laboratories, and help with communications 

regarding any round robin testing that might occur.

As proposed, we will phase in the part 1066 test procedures for certifying all sizes 

of chassis-tested vehicles. All aspects of part 1066 related to PM testing must be met at 

the start of MY 2017 for vehicles certified to the PM standards. All other aspects of part 

1066 must be met starting with the certification of MY 2022 vehicles. Manufacturers 

may begin using the part 1066 procedures before these deadlines, including step-wise 

changes to migrate gradually to part 1066 procedures. The regulations will require that 

good engineering judgment be used during this transition to ensure that the effective 

stringency of the standards is not changed. We recognize that individual differences 

between part 86 and part 1066 test procedures may have a slight upward or downward 

impact on measured emissions, even though the combined overall impact will be 
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negligible. Thus, during the migration, care must be taken to avoid applying an 

unbalanced mix of changes that could bias emissions.

As described in Section IV.D, we are finalizing new test fuel specifications for 

E10 gasoline test fuel in 40 CFR part 1065. The test fuels specified for natural gas and 

liquefied petroleum gas, while not used for very many engine families, are currently

following different specifications under 40 CFR part 86 and part 1065. We intend to 

revisit these fuel specifications in the future in the hope of adopting single, 

comprehensive fuel specifications for natural gas and liquefied petroleum gas that 

properly represent in-use fuels for highway and nonroad applications. 

The proposal also included various technical amendments to 40 CFR part 1065, 

which we are finalizing largely as proposed. See the Summary and Analysis of 

Comments for a discussion of changes we have made in response to comments. Of 

particular note is the revision to subpart F specific to preconditioning engines with 

exhaust aftertreatment devices. We are also adopting test procedures for unregulated 

pollutants such as semi-volatile compounds (PAHs, etc.). These technical amendments, 

which have no effect on the stringency of any emission standards, include several minor 

changes to clarify regulatory requirements, align with chassis-testing procedures where 

appropriate, and correct typographical errors.

2. Reduced Test Burden

We are updating the regulatory provisions that allow manufacturers to omit 

testing for certification, in-use testing, and selective enforcement audits in certain 

circumstances. Sections IV.A.3, IV.B.6, and IV.G.3 describe how this applies for 

demonstrating that vehicles meet the Tier 3 PM standards. We are also allowing 

manufacturers to omit PM measurements for fuel economy and GHG emissions testing 

that goes beyond the testing needed for certifying vehicles to the Tier 3 standards. 

Requiring such measurement would add a significant burden with very limited additional 

assurance that vehicles adequately control PM. We are also allowing manufacturers to 

ask us to omit PM and formaldehyde measurement for selective enforcement audits. If 

there is a concern that any type of vehicle would not meet the Tier 3 PM or formaldehyde 

standards, we will not approve a manufacturer’s request to omit measurement of these 

emissions during a selective enforcement audit.

The existing regulations have allowed for waived formaldehyde testing for 

gasoline- and diesel-fueled vehicles. The Tier 3 NMOG+NOX emission standards are 

stringent enough that it is unlikely that vehicles will comply with the NMOG+NOX

standards while exceeding the formaldehyde standards. We are therefore continuing this 

waiver practice, such that manufacturers of Tier 3 vehicles do not need to submit 

formaldehyde data for certification.
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3. Miscellaneous Provisions

The following additional certification and compliance provisions are included in 

the final rule:

 The certification practice for assigned deterioration factors that are available 

for both small volume manufacturers and small volume test groups has 

matured significantly since it was first adopted. We are revising §86.1826 to

more carefully reflect the current practice. For example, the existing 

regulations specified that manufacturers with sales volumes between 300 and 

15,000 units per year should propose their own deterioration factors based on 

engineering analysis of emission data from other families. We believe it is 

best for EPA to develop a set of assigned deterioration factors that can apply

to all small volume manufacturers and small volume test groups. The revised 

regulation accordingly spells out a process for EPA to use available 

information to establish assigned deterioration factors that can be used for any

number of manufacturers and test groups.

 The regulations in 40 CFR part 86 rely on rounding procedures specified in 

ASTM E29. This standard is revised periodically. The newer versions are not 

likely to change in a way that affects the regulation, but the updates make it 

difficult to maintain a coordinated reference to the current protocol. We are 

addressing this by specifying that the rounding protocol described in 40 CFR 

1065.20(e) applies, unless specified otherwise. We are not changing all the 

references in part 86; rather, we are defining “round” in subparts A and S to 

have the meaning given in 40 CFR part 1065 so that all new regulatory text 

would rely on this new description. The rounding specifications in 40 CFR 

part 1065 are intended to be identical to those in the latest versions of ASTM 

E29 and NIST SP811. For example, this now includes procedures for 

nonstandard rounding, such as rounding to the nearest 25 units, or the nearest 

0.05, where that is appropriate.

 Independent Commercial Importers (ICIs) are companies that import 

specialized vehicles into the U.S. and are subject to EPA requirements 

specified in 40 CFR part 85, subpart P. The standards that apply to the 

imported vehicles depend in part on the vehicle’s model year. Therefore, 

vehicles imported by ICIs in the future will eventually be subject to the Tier 3 

standards. Because all existing ICIs are small businesses, the Tier 3 standards 

generally do not apply until 2022 at the earliest. In addition, the certification 

practices for ICIs have matured significantly since they were first adopted. 

EPA is adopting two changes to update how the regulations affect ICIs. First, 

we are adopting a requirement for ICIs to use electric dynamometers when 

running exhaust emission tests. Electric dynamometers have been required 

for many years for vehicle manufacturers, and EPA believes it is time to 

require that ICIs use such test equipment. In cases where an ICI can 
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demonstrate that they will incur a substantial increase in compliance costs, the 

regulations include a provision allowing EPA to approve requests on a caseby-case basis to allow testing on other types of dynamometers until the ICI is 

able to use an electric dynamometer meeting current specifications. Second, 

we are adopting an allowance for ICIs to use a specific set of reduced testing 

procedures for up to 300 vehicles each year that have been modified to a U.S.-

certified configuration. This has been allowed for ICIs since 1999 and was 

approved under EPA’s authority to establish equivalent alternate test 

procedures.422 Instead of running a full set of emission tests, the reducedtesting requirements allow ICIs to run an FTP for exhaust emissions, a 

highway fuel economy test, and the hot soak test and the one-hour diurnal 

emission test that applied prior to the evaporative emission test procedures 

that involve 24-hour cycling of ambient temperatures. We do not believe 

these changes will have any significant cost impacts on ICIs. Most ICIs have 

electric dynamometers or can upgrade for a relatively small cost. The reduced 

testing burden provisions keep the cost of testing low, compared to the cost of 

running a full set of emission tests that would otherwise be required. 

 We are adopting CARB’s onboard diagnostic requirements for light-duty

vehicles, light-duty trucks, and heavy-duty vehicles at or below 14,000 lbs 

GVWR, as described in Section IV.C.5.d. We currently allow for this as an 

option, and almost all manufacturers do this already to avoid certifying 

multiple systems. Now that we are adopting evaporative provisions that are 

largely based on California’s regulatory specifications and we are making 

efforts to adopt a single, national regulatory program, we believe this is an 

appropriate step. These changes apply starting in MY 2017 for vehicles 

subject to Tier 3 standards. In the case of alternative fuel conversions, we 

continue to apply the requirements of 40 CFR 86.1806-05.

4. Manufacturer In-Use Verification Program (IUVP) Requirements

The fuel on which an in-use vehicle will be operated and tested is considered an 

integral part of the vehicle’s emission control system design. The Tier 2 program 

recognized that to achieve the desired emission reductions, vehicles must operate on the 

same fuel that the emission control system was originally designed to encounter in-use 

and during testing. In the Tier 2 program, we acknowledged that during the transition of 

the in-use fuel from sulfur levels of 300 ppm to 30 ppm average level, vehicles designed 

for 30 ppm could encounter in-use sulfur levels well above the level for which their 

emission control systems were designed. To address this issue, we allowed 

manufacturers, with agency approval, to perform specific preconditioning test procedures 

during the IUVP testing to ensure that potential exposure to high sulfur fuel would not 

 

422 See 40 CFR 86.106-96(a) and Enclosure 2 to EPA Guidance letter CCD-02-04, February 6, 2002.
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impact the emission test results. These procedures included specific drive cycles or 

maneuvers not regularly encountered during normal in-use operation that would result in 

removal of sulfur contamination from the emission control system. 

Consistent with the Tier 2 program, EPA continues to recognize the importance 

of the fuel to the emission control system design, particularly on Tier 3 vehicles designed 

to meet the most stringent emission levels of the program (i.e., Bin 70 and cleaner). 

Under the requirements of this final rule, in-use fuel will transition from an average 

sulfur level of 30 ppm to a new average level of 10 ppm. These sulfur requirements are 

average standards. Thus, even after the transition to the 10 pm average sulfur level, 

vehicles may still encounter sulfur levels during in-use operation that are above 10 ppm, 

and as high as the 95 ppm cap, which could adversely impact the emission control 

system. Tier 3 vehicles tested by manufacturers in IUVP that have been exposed to such 

sulfur levels could experience sulfur-related impacts, which in turn could cause the 

vehicle to temporarily exceed emission standards. 

To address the potential emission impact on Tier 3 vehicles from exposure to 

higher sulfur levels, we are modifying the IUVP testing process based in part on what 

was allowed under the Tier 2 program. Tier 3 vehicles tested in the IUVP are to be tested 

initially without allowing any sulfur cleanout procedure, such as a US06 test run prior to 

the FTP or Highway Fuel Economy (HFET) tests. If a vehicle fails the NMOG+NOX

standard for the FTP or HFET cycle during the initial round of testing, manufacturers 

may perform a sulfur cleanout procedure before repeating the FTP or HFET, consisting 

of up to two US06 cycles. The measured US06 cycle and a preconditioning US06 cycle, 

if performed as part of the initial measured tests would serve as the cleanout procedure 

and therefore no additional US06 cycles would be allowed. Alternative sulfur cleanout 

procedures would require EPA approval. Following the sulfur cleanout procedure, the 

manufacturer will prep and soak the vehicles and then repeat the FTP and HFET tests. 

Manufacturers choosing to perform the sulfur cleanout procedure would need to submit 

evidence that the vehicle encountered high sulfur levels in the fuel just prior to emission 

testing. This would need to include an analysis of a fuel sample from the vehicle fuel 

system as received from in-use operation just prior to testing. If the fuel sample indicated 

that the vehicle had been operating on fuel containing 15 ppm or higher sulfur levels, 

only the emission results of the tests following the cleanout procedure would be used to 

determine emission compliance and whether to enter the in-use compliance program 

(IUCP). We intend to monitor the emission results of in-use testing and sulfur-related 

test failures to determine if further reductions in the sulfur cap are required to ensure that 

Tier 3 vehicles are meeting the standards under in-use driving conditions.

The changes to the IUVP testing described above apply for light-duty vehicles, 

light-duty trucks, and MDPVs. These changes are not applicable to heavy-duty vehicles 

tested in the IUVP program. Also, as described in Section IV.D, we are incorporating 

leak testing into the IUVP test protocol. 

 
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V. Fuel Program

Under today’s Tier 3 program, we are finalizing reductions in gasoline sulfur 

levels nationwide. These standards will help reduce current levels of sulfur that 

contribute to ambient levels of air pollution that endanger public health and welfare. It 

will also help prevent the significant impairment of the emission control systems 

expected to be used in Tier 3 technology, significantly improve the efficiency of 

emissions control systems currently in use, and continue prevention of the substantial 

adverse effects of sulfur levels on the performance of vehicle emissions control systems.

A. Overview

1. Background

a. History of Gasoline Sulfur Control

Sulfur is naturally occurring in crude oil. Crude oil containing higher 

concentrations of sulfur (i.e., greater than 0.5 percent) is called “sour” and crude 

containing lower sulfur concentrations (e.g., West Texas Intermediate) is referred to as 

“sweet.” Regardless of the concentration, because sulfur is naturally occurring in crude 

oil, it is also naturally occurring in gasoline. As discussed in Section IV.A, sulfur impairs 

the performance of today’s vehicle emission control technologies (i.e., precious metal 

catalytic converters), reducing the emission benefits of current and advanced vehicles. 

As explained below, in 2000 EPA took action to reduce gasoline sulfur levels under what 

is known as the Tier 2 Program423 and we are taking further action with today’s Tier 3 

Program.

Tier 2 was a major, comprehensive program designed to reduce emissions from 

passenger cars, light trucks, and large passenger vehicles (including sport utility vehicles, 

minivans, vans, and pick-up trucks) and the sulfur content of gasoline. Under this 

program, automakers were required to manufacture low-emission vehicles when operated 

on low-sulfur gasoline, and refiners were required to produce low-sulfur gasoline 

nationwide. 

Required reductions in gasoline sulfur under the Tier 2 program began in 2004 

with refinery and importer caps of 300 ppm and a corporate average cap of 120 ppm. For 

most refiners and importers, compliance with the final sulfur standards (30 annual 

average and 80 per-gallon cap) was required beginning in 2006. The Tier 2 program was 

fully implemented on January 1, 2011 (the ultra-low sulfur diesel program allowed for 

some extensions of the Tier 2 gasoline program flexibility provisions). The Tier 2 

gasoline sulfur program also included an averaging, banking, and trading (ABT) program 

that allowed companies to generate credits for implementing the required changes earlier 

 

423 67 FR 6698 (February 10, 2000).
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than their required start date, and allowed ongoing flexibility to meet the 30 average 

sulfur standard.

At full implementation, the Tier 2 program (treating vehicles and fuels as a 

system) required passenger vehicles to be over 77 percent cleaner and gasoline sulfur to 

be reduced by up to 90 percent from pre-program levels.

b. Need for Additional Gasoline Sulfur Control

The authority under which we are lowering the existing gasoline sulfur standards 

comes from Clean Air Act section 211(c)(1). This is because emission products of 

gasoline with current levels of sulfur cause or contribute to air pollution which may

reasonably be anticipated to endanger public health or welfare, and because emission 

products of gasoline with current levels of sulfur will impair to a significant degree the 

emissions control device or systems on the vehicles subject to today’s final Tier 3 

standards. For more on our legal authority to set gasoline sulfur standards, refer to 

Section V.M.

As explained in Section IV.A, robust data from many sources show that gasoline 

sulfur at current levels (i.e., around 30 ppm on average) continues to degrade vehicle 

catalytic converter performance during normal operation. NOx emissions are the most 

significantly affected by this degradation. The NMOG+NOX vehicle emission standards, 

representing an 80 percent reduction from current Tier 2 standards, will not be possible 

without the gasoline sulfur controls we are finalizing today. Today’s 10 ppm sulfur 

standard should enable vehicle manufacturers to certify their entire product line of 

vehicles to the final Tier 3 fleet average standards. Tier 3 vehicles must achieve 

essentially zero warmed-up NOX emissions to comply and must maintain this 

performance for up to 150,000 miles. An increase in emissions of only a few milligrams 

per mile due to sulfur could make compliance impossible for some vehicles. The 

standards are projected to be especially challenging for larger SUVs and pick-up trucks. 

Based on testing of these vehicles, as shown in Section IV.A, reducing gasoline sulfur to 

10 ppm should enable these vehicles to maintain their emission performance in-use over 

their useful life. Lowering gasoline sulfur will also help reduce emissions of pollutants 

that endanger public health and welfare from vehicles already on the road today. As also 

discussed above in Section IV.A, we have tested a wide range of vehicles to better 

understand the impact that even lower gasoline sulfur could have on emissions. Our test 

data showed significant NOX and VOC reductions when vehicles were tested on low 

sulfur gasoline. As also explained in more detail in Section III.B, lowering average 

gasoline sulfur from 30 to 10 ppm will result in approximately 260,000 less tons of NOX

and 50,000 less tons of VOC almost immediately as the Tier 3 gasoline sulfur standards 

take effect. 
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2. Summary of Final Tier 3 Fuel Program Standards

The major elements of the fuel program being finalized today are summarized 

below. Please refer to sections V.B through V.J for more discussion on each of the 

elements summarized here.

a. Annual Average Sulfur Standard

Under today’s final Tier 3 fuel program, gasoline and any ethanol-gasoline blend 

will be required to have a sulfur level of 10 ppm or less on an annual average basis 

beginning January 1, 2017. The 10 ppm average will apply to a refiner or importer’s 

annual gasoline production. Similar to the Tier 2 gasoline program, the Tier 3 program 

applies to gasoline in the United States and the U.S. territories of Puerto Rico and the 

Virgin Islands, excluding California. Please see Section V.B for a more detailed 

discussion of the annual average sulfur standard.

b. Per-Gallon Sulfur Caps

Refiners and importers will continue to be subject to refinery gate per-gallon 

sulfur caps of 80 ppm. Similarly, gasoline downstream of the refinery gate (e.g., at 

terminals, retail stations, etc.) will continue to be subject to a 95 ppm per-gallon sulfur 

cap. We are also committing to continue to evaluate if reductions in the per-gallon sulfur 

caps are warranted.

A more detailed discussion on our decision to continue the current 80 and 95 ppm 

per-gallon sulfur caps, and elements of an in-use study, can be found below in Section 

V.C.

c. Small Refiner and Small Volume Refinery Provisions

As described in further detail in Section V.E.1, approved gasoline small refiners 

and small volume refineries must produce gasoline meeting the 10 ppm annual average 

sulfur standard beginning January 1, 2020. Small refiners and small volume refineries 

who meet the 10 ppm sulfur standard prior to this date may generate credits for early Tier 

3 program compliance.

d. Averaging, Banking, and Trading (ABT) Program

Section V.D discusses our averaging, banking, and trading (ABT) program. 

Refiners and importers may continue to generate credits for reductions in their gasoline 

sulfur levels below the current (Tier 2) 30 ppm average gasoline sulfur standard through 

December 31, 2016; and for reductions below the new 10 ppm average standard 

beginning January 1, 2017. These credits can be used for compliance with either the Tier 

2 standard through 2016 or the Tier 3 standard beginning in 2017. The Tier 3 ABT 

program will have similar credit use provisions as the Tier 2 ABT program. These 

provisions include: five-year credit life from the year of generation; two-trade limit for 
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inter-company trading; and the ability to use credits internally, bank for future use, or 

trade to other refiners/importers. Although credits generated prior to January 1, 2017 

will be valid for five years or until December 31, 2019, whichever is earlier. 

e. Gasoline Additive Cap

As discussed further in Section V.C., manufacturers of gasoline additives that are 

used downstream of the refinery at less than 1.0 volume percent will be required to limit 

the sulfur contribution to the finished gasoline from the use of the additive to less than 3 

ppm when the additive is used at the maximum recommended treatment rate. For each 

batch of additive produced, the manufacturer must retain sulfur test records for 5 years, 

and must make these records available to EPA upon request.

Parties that introduce additives to gasoline at over 1.0 volume percent will be 

required to satisfy all of the obligations of a refiner and fuel manufacturer, including 

demonstration that the finished blend meets the applicable sulfur specification.

f. Requirements for Denatured Fuel Ethanol and Other Gasoline Oxygenates

Today’s rule finalizes a 10 ppm sulfur cap for denatured fuel ethanol (DFE). 

While DFE is the predominant gasoline oxygenate currently in use, these standards also 

apply to other gasoline oxygenates. Today’s rule finalizes a 3.0 volume percent limit on 

ethanol denaturant concentration. We are adopting the current ASTM International 

specifications that only natural gasoline, gasoline blendstocks, or gasoline may be used as 

denaturants for DFE.424 As discussed in the Summary and Analysis of Comments, we 

believe it is not necessary to finalize the proposed additional limits on the potential 

denaturants that may be used at this time. We are also finalizing regulatory text to state 

that DFE must be composed solely of carbon, hydrogen, oxygen, and sulfur. Testing, 

recordkeeping, and reporting obligations are also being finalized to implement these new 

standards as discussed in Section V.G. Sulfur testing using approved analytical methods 

or volumetric blending records and denaturant product transfer documents (PTDs) can be 

used by manufacturers/importers of DFE in demonstrating compliance with the 10 ppm 

sulfur cap for DFE finalized today. 

g. Fuel Used in Flexible Fuel Vehicles

As discussed in Section V.H., we are deferring finalizing additional fuel quality

requirements for E16-50 and E51-83 at this time. We continue to believe in the 

importance of implementing additional fuel quality standards for higher-level ethanol 

blends and will continue to work with stakeholders in their development following the 

publication of this final rule. 

 

424 ASTM D4806-13a, “Standard Specification for Denatured Fuel Ethanol for Blending with Gasoline for 

Use as Automotive Spark-Ignition Engine Fuel”. 
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h. Standards for Butane and Pentane

As discussed further in Section V.I, we are finalizing a 10 ppm sulfur cap for 

butane blended into gasoline effective January 1, 2017. This is consistent with the Tier 3 

10 ppm refinery average sulfur specification finalized today. In addition, as discussed 

below in Section VI.A.4, we are also finalizing provisions to allow pentane to be blended 

into gasoline downstream of the refinery. These provisions are similar to the existing 

provisions for butane blending. This allowance will become effective [INSERT DATE 

60 DAYS AFTER PUBLICATION IN THE FEDERAL REGISTER]; a 30 ppm sulfur 

cap will apply to pentane blended into gasoline (consistent with the existing sulfur cap for 

butane under the Tier 2 program) until December 31, 2016, after which a 10 ppm sulfur 

cap will apply.

i. CNG/LPG

As discussed below in Section V.J, we are deferring establishing in-use sulfur 

requirements for compressed natural gas (CNG) and liquid propane gas (LPG) to provide 

additional time to work with stakeholders to collect data on current CNG/LPG sulfur 

content; to determine whether additional control of in-use CNG/LPG sulfur content is 

needed; and to evaluate the feasibility and costs associated with potential additional 

sulfur controls. 

B. Annual Average Sulfur Standard

Under today’s final Tier 3 fuel program, gasoline and any ethanol-gasoline blend 

will be required to have a sulfur level of 10 ppm or less on an annual average basis 

beginning January 1, 2017. The 10 ppm average will apply to a refiner or importer’s 

annual gasoline production. Similar to the Tier 2 gasoline program, the Tier 3 program 

applies to gasoline in the United States and the U.S. territories of Puerto Rico and the 

Virgin Islands, excluding California. We are finalizing the 10 ppm average sulfur 

standard both to enable the new vehicle fleet to meet the Tier 3 vehicle standards being 

finalized today pursuant to CAA section 211(c)(1)(B), and to reduce emissions from the 

existing in-use vehicle fleet that endanger public health and welfare pursuant to section 

211(c)(1)(A) of the Clean Air Act (CAA). 

We received numerous comments both in support of and against the proposed 10 

ppm annual average sulfur standard. Commenters opposing the standard believe that 10 

ppm is too low and/or is not needed to enable Tier 3 vehicle technologies. Some 

commenters suggested that EPA should consider setting a less stringent sulfur standard 

than the proposed 10 ppm annual average (detailed information regarding the comments 

can be found in the Summary and Analysis of Comments document, which is located in 

the docket for this rulemaking). We believe that a 10 ppm annual average standard will 

help reduce current levels of sulfur that contribute to ambient levels of air pollution that 

endanger public health and welfare. It will also help prevent the significant impairment 

of the emission control systems expected to be used in Tier 3 technology, significantly 
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improve the efficiency of emissions control systems currently in use, and continue 

prevention of the substantial adverse effects of sulfur levels on the performance of 

vehicle emissions control systems. This level is also feasible, and is the level that 

appropriately balances costs with the emission reductions that it provides and enables. 

As discussed in Section IV.A.6., and further in Chapter 5 of the RIA, we believe 

that a standard of 10 ppm is appropriate, and when combined with the advances in 

emissions control technologies will be sufficient to meet the Tier 3 emissions standards. 

The feasibility of the 30 mg/mi NMOG+NOx fleet average depends on exhaust catalyst 

systems that require gasoline with average sulfur levels of 10 ppm or less. Further, 

annual average sulfur levels greater than 10 ppm would significantly impair the emission 

control technology that we expect will be used to meet the Tier 3 standards and to ensure 

in-use compliance over a vehicle’s useful life. This is particularly a concern for some 

larger vehicles that will need to reduce NOx to near-zero levels, due to greater difficulty 

in reducing cold-start NMOG, in order to meet a combined NMOG+NOx standard. As 

discussed in Section IV.A.6, increasing gasoline sulfur from 10 ppm to 20 ppm or 30 

ppm would make it impossible for vehicle manufacturers to meet the Tier 3 standards. 

Achieving Tier 3 standards would require offsetting the resultant higher emissions but 

EPA is not aware of existing technology or developing technology that could address 

these higher emissions when taking into consideration the entire vehicle fleet. Increasing 

gasoline sulfur from 10 ppm to 20 ppm or 30 ppm would also forego the very large 

immediate reductions from the existing fleet. 

We also do not believe a sulfur standard lower than 10 ppm is necessary to enable 

vehicles to meet the Tier 3 standards. As also discussed in Section IV.A, reducing sulfur 

below 10 ppm would further reduce vehicle emissions and allow the Tier 3 vehicle 

standards to be achieved more easily. However, we believe that a 10 ppm average 

standard is sufficient to allow vehicles to meet the Tier 3 standards. Furthermore, as 

discussed below, there are significant challenges associated with reducing sulfur below 

10 ppm. 

As explained in Section IV.A, sulfur in fuel oxidizes in the exhaust and coats the 

sites where chemical reactions can take place on the precious metal catalysts used in 

vehicles to reduce emissions of VOC, NOX, PM, CO, and toxics. Accordingly, any sulfur 

in gasoline causes vehicle emissions to increase. Sulfur can be burned off the catalyst 

during high-temperature, rich operation of the vehicle (i.e., aggressive driving 

conditions), but as long as there is any sulfur in the fuel, exhaust emissions will increase. 

Because any amount of sulfur in the fuel can have this effect, the lower the sulfur the 

better. Refiners experience the same phenomenon with precious metal catalysts used in 

the reformer and isomerization units at their refineries.425 To protect the precious metal 

 

425 Together, the streams from the reformer and isomerization units account for approximately one-third of 

gasoline. 
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catalysts in these units, refiners reduce the sulfur in the feed to these units to 1 ppm or 

below. Thus, it is technically possible for refiners to reduce their gasoline sulfur levels to 

virtually zero. While refiners did not have reason to reduce the sulfur in FCC gasoline 

until Tier 2 required such reductions, some refiners have achieved reductions in this 

stream at some of their refineries for other reasons such as: 1) protecting the FCC catalyst 

from the contaminants in the gas oil feed, 2) reducing stack emissions from the 

regenerator of the FCC unit, and most importantly 3) increasing gasoline yields from the 

FCC unit. For most refineries, FCC gasoline accounts for about one-third of gasoline and 

before Tier 2 was the source of over 95 percent of the sulfur in gasoline. Under Tier 2,

most refiners significantly desulfurized FCC gasoline to around 70 to 80 ppm, yet FCC 

gasoline continues to contribute the majority of sulfur in gasoline today.

An annual average sulfur level of 10 ppm will achieve very large immediate 

reductions from the existing fleet, as discussed in Sections III and IV. Because any sulfur 

in gasoline will continue to impair vehicle catalyst performance, reducing sulfur levels to 

zero would maximize vehicle emission reductions. However, there are two reasons why

we believe a 10 ppm average sulfur standard is sufficient and further reductions (e.g., 10 

ppm cap or 5 ppm average) are not necessary at this time. First, our analysis shows that a 

10 ppm annual average is sufficient to enable vehicles to reach the Tier 3 standards. 

Consequently, while reducing sulfur levels further would continue to yield reductions 

from the in-use fleet, they would not be necessary to enable the new Tier 3 vehicle 

standards to be met. Second, while sulfur levels would continue to reduce emissions 

from the existing fleet, reducing sulfur further below 10 ppm becomes increasingly 

difficult and costly. FCC naphtha is very rich in high-octane olefins. As the severity of 

desulfurization increases, more olefins are saturated, further sacrificing the octane value 

of this stream and further increasing hydrogen consumption. Making up for this lost 

octane represents a significant portion of the sulfur control costs. Furthermore, as 

desulfurization severity increases, there is an increase in the amount of sulfur removed (in 

the form of hydrogen sulfide) which recombines with the olefins in the FCC naphtha, 

thus offsetting the principal desulfurization reactions. There are means to deal with the 

recombination reactions, but they result in even greater capital investments. In addition, 

while FCC gasoline contributes the majority of sulfur to the finished gasoline, as the 

sulfur level drops below 10 ppm, the sulfur level of the various other gasoline streams 

within the refinery also become important. Any necessary treatment of these additional 

streams increases both capital and operating costs. 

U.S. refineries are currently in different positions, both technically and 

financially. In general, they are configured to handle the different crude oils they process 

and turn them into a widely varying product slate to match available markets. Those 

processing heavier, sour crudes may have a more challenging time reducing gasoline 

sulfur under the Tier 3 program. Also, those with higher sulfur levels in other refinery

streams may have a more difficult time desulfurizing gasoline. Perhaps most important, 

U.S. refineries vary greatly in size (atmospheric crude capacities range from less than 

5,000 to more than 500,000 barrels per day) and thus have different economies of scale 

for adding capital to their refineries. Therefore, it can be less costly per gallon for some 
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larger refineries to get down to 10 ppm than for smaller refineries, as discussed in 

Chapter 5 of the RIA. As a result, with a 10 ppm average standard, the flexibility

afforded by the ABT program helps those refineries with very high costs. They have the 

option of staying above 10 ppm if they can acquire credits from other refineries that were 

able to lower their sulfur level below 10 ppm. However, if the gasoline sulfur standard 

were lower, this would essentially end the ability of refiners to average sulfur reductions 

across their refineries. There simply would not be enough opportunity to generate credits 

at levels much below 10 ppm. 

As discussed further in Chapter 5 of the RIA, we assessed the potential costs of an 

annual average standard lower than 10 ppm (e.g., 5 ppm). Our analysis shows that sulfur 

control costs for refineries to meet a standard below 10 ppm could be on the order of two 

times more costly per ppm-gallon of gasoline sulfur reduced. In addition, a standard 

below 10 ppm could be cost-prohibitive for more challenged refineries. Further, such a 

standard would also introduce additional costs to address the contribution to gasoline 

sulfur from gasoline additives, transmix, ethanol denaturants, and contamination in the 

distribution system. 

Therefore, we believe that the 10 ppm annual average standard will help reduce 

current levels of sulfur that contribute to ambient levels of air pollution that endanger 

public health and welfare. It will also help prevent significant impairment of the 

emission control systems expected to be used in Tier 3 technology, significantly improve 

the efficiency of emissions control systems currently in use, and continue prevention of 

the substantial adverse effects of sulfur on the performance of vehicle emissions control 

systems. The level is also feasible (especially considering its associated ABT provisions, 

described in Section V.D), and is the point which appropriately balances costs with the 

emission reductions that it provides and enables.

C. Per-Gallon Sulfur Caps

1. Standards

The final Tier 3 program is composed of a 10 ppm refinery annual average sulfur 

standard (discussed above in Section V.B) with an 80 ppm per-gallon cap at the refinery

gate and a 95 ppm per-gallon cap downstream; these per-gallon caps currently exist under 

the Tier 2 program. We believe this is the most prudent approach for lowering in-use 

sulfur while maintaining flexibility considering cost and other factors. These per-gallon 

caps are important in the context of an average sulfur standard to provide an upper limit 

on the sulfur concentration that vehicles must be designed to tolerate. The caps also limit 

downstream sulfur contamination and enable the enforcement of the gasoline sulfur 

standard in-use. Our 10 ppm average standard with higher per-gallon caps compares to a 

10 ppm cap standard in much of Europe, Japan, and Korea. In addition to the gasoline 

standards we are finalizing today, we are also finalizing caps on the sulfur content of 

gasoline additives, to limit their contribution to the overall in-use gasoline sulfur level. 
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a. What We Proposed

We proposed two options for the per-gallon sulfur caps—maintaining the Tier 2 

80 ppm refinery gate sulfur and 95 ppm downstream sulfur caps and, beginning January

1, 2020, lowering to 50 ppm refinery gate and 65 ppm downstream caps. The 50 ppm 

refinery gate cap was proposed to take effect on January 1, 2020, as this is the date when 

the small refiner, small volume refinery, and early credit use provisions would expire; 

and also to avoid forcing additional refinery investments during the early credit usage 

period. We also requested comment on lowering the caps to 20 ppm at the refinery gate 

and 25 ppm downstream.

We received comments on both of the proposed per-gallon cap options of 80/95 

ppm and 50/65 ppm, as well as comments on finalizing lower caps of 20/25 ppm and a 20 

ppm overall cap. Comments supporting lower caps noted potential environmental 

benefits, greater certainty that vehicles would see lower and more uniform gasoline sulfur 

levels, and enabling new vehicle technologies that require very low sulfur levels. 

Comments in support of maintaining the current Tier 2 caps cited concerns on cost, 

flexibility for turnarounds/unplanned shut downs (due to refinery fire, natural disaster, 

etc.), and potential impacts on gasoline supply and pricing. Detailed information 

regarding the comments we received on the per-gallon sulfur caps is provided in the 

Summary and Analysis of Comments document, which is available in the rulemaking 

record.

b. Final Refinery Gate Sulfur Cap

In today’s action, we are retaining the 80 ppm refinery gate cap. The refinery

gate cap provides flexibility for batch-to-batch variability that naturally occurs at a 

refinery due to the varying types of crude that refineries process, variations in unit 

operations, and variations in product mix. It further provides for flexibility during unit 

turnarounds, and unplanned upsets (e.g., refinery fires, natural disasters, etc.), to avoid a 

complete refinery shutdown. A lower cap could create situations where refiners would 

need to store more off-spec gasoline for future processing. However, if a refinery does 

not have adequate tankage for storing this product, and/or if its processing units are not 

large enough to “catch up” in refining off-spec product, it could result in significant 

impacts to fuel pricing or supply. For a refiner that produces multiple products, any

potential supply impacts could also impact other fuel markets (e.g., diesel, jet fuel, etc.). 

Additionally, the refinery gate cap is a “hard” limit—a refinery’s actual production has to 

be well below this limit to account for in-use testing tolerances, safety margins, and any 

additives that a refiner may need to add prior to the fuel leaving the refinery. An 80 ppm 

refinery gate cap will provide refiners needed flexibility, and more certainty that they will 

be able to continue producing and distributing at least some gasoline during 

turnarounds/upsets to avoid a total shutdown. It will further provide more certainty for 

transmix processors, additive manufacturers and other downstream parties.
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As described below in Section VII, we believe that most refineries would not have 

significant costs as a result of the Tier 3 program because they will be able to meet the 10 

ppm average sulfur standard largely through revamps and operational changes at their 

facilities, rather than installing grassroots units. Lowering to a cap of 50 ppm would 

directionally increase the costs of the Tier 3 program. The American Petroleum Institute 

(API) provided a detailed study with their comments426 quantifying the additional costs 

associated with successively more stringent per-gallon caps. While we do not agree with 

the study’s overall cost analysis, we do agree that with a refinery gate cap of 50 ppm, a 

number of refiners would incur higher capital costs due to the decreased ability to handle 

off-spec product with a lower refinery gate cap. As refiners must ensure that they can 

continue to produce saleable product and meet demand in the event of an upset or an offspec batch of fuel, the need for installation of additional tankage and/or increased refinery

processing capability would be greater with a 50 ppm refinery gate cap. While at the 

time of the proposal we believed that a cap of 50 ppm would have little cost impact, our 

more recent analysis shows that a 50 ppm cap would increase the cost of the Tier 3 

gasoline sulfur standards by approximately 10 percent (see RIA Chapter 5.2.2.4). At the 

same time, the more stringent cap with its associated increase in cost would be unlikely to 

provide significant additional emission benefits nationwide. As discussed previously in 

Sections III and IV above, the emissions benefits associated with the Tier 3 program are 

mainly driven by the reduction in the average sulfur content of gasoline from 30 to 10 

ppm, since vehicle emissions are proportional to the sulfur content of the fuel. Changes 

in the cap would not affect this. In the context of the final ABT provisions, a higher cap 

does allow for increases in emissions on a temporal basis as one batch of fuel is allowed 

to have higher sulfur levels. However, this is then offset by reductions in emissions from 

batches of fuel that are then required to be below the 10 ppm average standard. 

Similarly, the final ABT provisions allow for the possibility that the fuel from different 

refineries will cause varying emission reductions as one refinery’s higher average sulfur 

levels would lead to less emission reductions in-use. However, this is then offset by 

greater reductions in emissions due to the fuel produced by refineries with sulfur levels 

below the average standard.

Based on our cost analysis, which is discussed below in Section VII.B., we 

project nearly 40% of the gasoline pool would be at 5 ppm, about 45% at 10 ppm and the 

remaining approximately 15% at levels higher than 10 ppm. The sulfur level for this 

15% in our analysis ranges from 11 ppm all the way up to 70 ppm. However, as 

discussed in Section VII.B., these high sulfur levels are more a function of the limitations 

of our analysis where we could only model these refineries as remaining at their current 

Tier 2 sulfur levels. We anticipate that in most (if not all) cases refineries will make 

operational changes and/or investments in order to reduce their credit burden and reduce 

 

426 “Economic and Supply Impacts of a Reduced Cap on Gasoline Sulfur Content; Prepared for the

American Petroleum Institute”; Turner, Mason & Company. Document number: EPA-HQ-OAR-2011-

0135-4285; API-AFPM Attachment 13.
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their compliance costs. This anticipation, along with the fact that a 10 ppm average 

standard by definition limits the amount of gasoline that can remain at higher sulfur 

levels (regardless of the cap), means that we anticipate most refineries, including those 

using credits, will still average less than 20 or 30 ppm in their physical gasoline 

production. Nevertheless, the final ABT program does allow for the possibility

(regardless of the cap) that were this higher sulfur fuel to be concentrated in any certain 

geographical area, it would not receive the full emission reductions from the Tier 3 

program. We have considered the potential for areas to consistently receive fuel that 

might be predominantly higher than the 10 ppm average. Because refineries generating 

credits and using credits are interspersed across the country, and because most areas 

receive a considerable portion of their fuel by pipeline, barge, rail, or truck from 

refineries in other areas, we expect the variation in average sulfur levels across the 

country to be too limited to warrant lowering the per-gallon cap to 50 ppm. Given the 

stringency of the 10 ppm average standard, we predict that in-use sulfur levels will 

generally be well below 50 ppm. 

Further reductions in the refinery gate cap are also not needed to enable the 

vehicle emissions standards, as the vehicle standards are a function of the 10 ppm annual 

average sulfur standard. While vehicle manufacturers have expressed concerns about the 

potential impacts on emissions performance if individual vehicles are exposed to gasoline 

above 10 ppm due to higher per-gallon caps and/or credit usage427, we believe that 

vehicles will see sulfur levels closer to the 10 ppm average rather than the 80 ppm cap 

due to the fact that the 10 ppm average will drive reductions in gasoline sulfur levels.

Thus, we believe it is prudent at this time to retain an 80 ppm refinery gate cap. 

However, we are committing to monitor and further evaluate in-use sulfur levels and their 

impact on vehicle emissions. If it is warranted, we will reassess the sulfur cap level and 

the need for potential future regulatory action. Such ongoing evaluation will include 

analyses of: in-use fuel surveys; batch data that refineries are required to submit; and the 

sulfur credit market. It will also include the evaluation of any issues or concerns that 

might arise during implementation of the program. Finally, we will also carry out an 

ongoing evaluation of data submitted by the vehicle manufacturers on the performance of 

their Tier 3 vehicles in-use. 

c. Downstream Sulfur Cap

With regard to the downstream sulfur cap, we believe that maintaining a 15 ppm 

differential between the refinery gate sulfur cap and the downstream sulfur cap will 

provide pipeline operators, transmix processors, and gasoline additive users the same 

flexibility as was provided under the Tier 2 program. As was the case under the Tier 2 

program, allowing a 15 ppm differential is needed to ensure adequate flexibility in 

 

427 Alliance of Automobile Manufacturers (2011, October 6). Letter to EPA Administrator, Lisa Jackson.
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accommodating gasoline produced from transmix, instances of contamination during 

distribution, and for the use of necessary (sulfur-containing) additives. In rare 

circumstances when the sulfur contribution from all these sources are coincidently at their 

maximum levels, a very limited number of batches of gasoline at the 95 ppm downstream 

sulfur cap may be present in the distribution system. However, we expect that this will 

not have a substantial impact on the average sulfur content of in-use gasoline. Comments 

received on this issue were generally in support of maintaining the 15 ppm delta.

Pipeline operators are currently allowed to blend limited volumes of transmix into 

gasoline in their systems provided that the resulting gasoline meets all fuel quality

specifications and the endpoint of the blended gasoline does not exceed 437 °F.428 This 

enables pipeline operators to avoid the installation of additional transmix storage and 

loading equipment at a number of remote locations to facilitate shipping small volumes 

of transmix to processing facilities by truck. 

Currently transmix processors must produce gasoline sufficiently below the 95 

ppm downstream sulfur cap to accommodate any downstream sulfur increases from the 

use of gasoline additives and contamination from further distribution. The sulfur content 

of the gasoline produced by transmix processors is determined by the sulfur content of 

the transmix they receive, which in turn is primarily a function of the sulfur content of 

gasoline and jet fuel components in the transmix.429 Transmix processors do not handle 

sufficient volumes to support the installation of currently available desulfurization 

units.430 

d. Accounting for Ethanol Blending in the Determination of Compliance with 

Gasoline Sulfur Requirements

In demonstrating compliance with the gasoline sulfur standards finalized today, 

gasoline refiners and importers may adjust the sulfur levels in the gasoline and 

blendstocks for oxygenate blending (BOBs) that they produce/import to account for the 

downstream addition of ethanol. We proposed that the sulfur content of denatured fuel 

ethanol (DFE) used for downstream blending would be assumed to be 10 ppm in making 

such demonstrations of compliance. Refiners commented that refiners and importers 

should be allowed to either use the actual sulfur value of the DFE or conduct laboratory

hand blends of a representative sample of DFE to determine the effect on the sulfur 

content of the blended fuel from the addition of DFE. We agree that refiners and 

 

428 The requirements for transmix blenders are contained in 40 CFR 80.84(d). 437 °F is the maximum 

endpoint allowed for gasoline in ASTM D4814. 

429 Transmix is a by-product of the multi-product pipeline distribution system. 40 CFR 80.84(a) defines 

transmix pipeline interface that does not meet the specifications for a fuel that can be used or sold, and that 

is composed solely of any combination of: previously certified gasoline (including previously certified 

gasoline blendstocks that become gasoline solely upon the addition of an oxygenate); distillate fuel; or 

gasoline blendstocks that are suitable for use as a blendstock without further processing.

430 Transmix processors produce ~0.1 percent of the gasoline consumed in the U.S.
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importers should be allowed to use the actual sulfur content of DFE when a sulfur test 

result is available and when the refiner can demonstrate that the test result was derived 

from a representative sample of the DFE that was blended with the gasoline or BOB. 

The sulfur content of in-use DFE will typically be lower than the 10 ppm sulfur cap 

finalized today for DFE. We assumed that DFE would have an average sulfur content of 

5 ppm in conducting the refinery analysis to support this rule. Therefore, today’s final 

rule requires that in determining their compliance with today’s sulfur standards, refiners 

and importers must either use the actual sulfur content of the DFE established through 

testing of the DFE actually blended or assume a 5 ppm sulfur content for the DFE added 

downstream. To prevent potential bias, a refiner or importer must choose to use only one 

method during each annual compliance period. 

2. Requirements for Gasoline Additives

Today’s action finalizes the requirement that manufacturers of gasoline additives 

used downstream of the refinery at less than 1 volume percent must limit the sulfur 

contribution to the finished gasoline from the use of their additive to no more than 3 ppm 

when the additive is used at the maximum recommended treatment rate. The additive 

manufacturer will be required to maintain records of its additive production quality

control activities which demonstrate that the sulfur content of additive production batches 

is such that when the additive is used at its maximum recommended treatment rate it will 

add no more than 3 ppm to sulfur content of the finished gasoline. We received 

comments in support of our proposed requirements (these comments can be found in the 

docket to this rulemaking, and are summarized in the Summary and Analysis of 

Comments document, which is also located in the docket). An environmental 

organization commented that the sulfur contribution from additives can have a material 

effect on emissions performance given the level of vehicle emissions control that is being 

finalized today. We also received comments from gasoline additive manufactures were 

in favor of the proposed controls. 

The requirements finalized today are designed to prevent the potential dumping of 

high sulfur materials into gasoline under the guise of the addition of gasoline additives. 

We continue to believe that all current gasoline additives contribute less than 3 ppm to 

the sulfur content of the finished fuel when used at the maximum recommended 

treatment rate (with 3 ppm being the extreme). Normal additive production quality

control practices already have had to consider the sulfur contribution of the additive to 

finished gasoline as a result of the Tier 2 gasoline sulfur requirements. The maximum 

recommended treatment rate is already stated on product transfer document or packaging 

for the additive. Additive manufacturers are to retain production quality control records 

for 5 years and make these available to EPA upon request. Therefore, the requirements 

finalized today will not constrain the use of genuine gasoline additives or result in 

significant additional costs to gasoline additive manufacturers. Parties that introduce 

additives to gasoline at over 1.0 volume percent are required to satisfy all of the 

obligations of a refiner and fuel manufacturer including demonstration that the finished 

blend meets the applicable sulfur specification.
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We also received comments from an environmental organization requesting that 

EPA promulgate limits on the combined sulfur contribution for all additives blended into 

a batch of gasoline in addition to controlling the sulfur contribution from individual 

additives. We believe that such additional controls are not necessary, would add an 

unwarranted additional compliance burden, and could interfere with the use of necessary 

downstream additives. Certain additives that provide critical fuel performance 

characteristics (e.g., corrosion control, demulsifiers) contain sulfur-containing 

compounds as an essential functional component. Such additives are used to remedy 

specific instances of gasoline quality problems, and their treatment rate is governed by 

the desire to limit the added cost from their use.

D. Averaging, Banking, and Trading Program 

In today’s rule, we are finalizing an ABT program that will reduce the compliance 

costs and promote the feasibility of the Tier 3 gasoline sulfur program, because it will 

allow refiners and importers to choose the most economical compliance strategy (i.e., 

investment in technology, credits, or both) to meet the 10 ppm average sulfur standard. 

In response to comments received on our proposal, we have simplified and added 

flexibility to the ABT program. The ABT program allows refiners and importers to 

continue to generate credits for overcompliance with the current Tier 2 30 ppm average 

gasoline sulfur standard through 2016, and the new 10 ppm average standard beginning 

in 2017. (Small refiners and small volume refineries have a January 1, 2020 compliance 

date, as described below.) These credits can be used for compliance with either the Tier 

2 standard through 2016 or the Tier 3 standard beginning in 2017. Credits can also be 

banked for future use or transferred to other refineries for compliance with the average 

sulfur standard. In addition, we are allowing refiners and importers to also use any valid 

credits banked from 2012 and 2013 under the Tier 2 program toward compliance with 

either the Tier 2 or Tier 3 sulfur programs. We believe these provisions will provide a 

seamless transition from Tier 2 to the Tier 3 program.

1. How Will the ABT Program Assist with Compliance?

The Tier 3 ABT program allows refiners and importers the flexibility to: 1) have 

varying gasoline sulfur levels for their batches of fuel as long as they meet the 10 ppm 

average over the course of the year; 2) use credits generated at one of its refineries to 

offset higher sulfur gasoline produced at another of its refineries; 3) bank generated 

credits for future use; and 4) participate in trading (via buying and/or selling) of credits 

from another refiner to help lower costs. The ABT program allows for the generation of 

credits by refiners and importers for over-compliance with the 10 ppm sulfur standard (on 

a refinery/facility basis), and for the transfer of these credits to other refiners (for use a 

refinery) to reduce or eliminate their need to make capital investments to meet the 10 

ppm standard. The ABT program will provide refiners and importers with multiple 

approaches to compliance, and each can choose the approach that best minimizes their 

costs.
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2. ABT Modeling

For the proposed rule, we modeled the effects of an ABT program on refinery

compliance. Our modeling determined the lowest cost approach on a refinery-by-refinery

basis under two scenarios: the first, in which every refinery has the opportunity to make 

credit transfers with every other refinery in the nation, and a more limited scenario in 

which credit transfers would only occur within companies that own more than one 

refinery.

In developing today’s final program, we also analyzed the Tier 2 credit market 

and found that, currently, Tier 2 sulfur credits are both transferred within companies 

(intra-company) and traded between companies (inter-company). As discussed in 

Chapter 4.3 of the RIA, in 2012 approximately 56% of the Tier 2 credit transactions were 

inter-company trades. The remaining 44% were intra-company trades. This analysis 

shows that there is a functioning, well-established gasoline sulfur credit trading market. 

There does not appear to be any hindrance to credit trading currently or in the future. We 

anticipate that a significant number of refineries will take advantage of the opportunity to 

generate or use credits, thus lowering their compliance burden for the Tier 3 program. 

For a more complete discussion of our analysis of credit trading and the associated cost 

impacts of the ABT program, refer to Chapter 4.3 of the RIA. 

3. Eligibility

Consistent with our proposal, under today’s final program, sulfur credits may be 

generated by both U.S. refiners and importers of gasoline into the U.S. only for gasoline 

that is subject to the sulfur requirements as described in the regulations at §80.1603. This 

excludes gasoline produced or imported for use in California (“California gasoline”) and 

gasoline designated for export, but includes gasoline produced by California refineries for 

use outside the state. We sought comment in the proposed rule on whether or not to 

include California. All comments received on this issue were against the inclusion of 

such gasoline in the ABT program, largely because it would cause additional burden but 

provide no appreciable credits to the market to justify the additional compliance burden 

(such as batch reporting). We agree with these comments, and are finalizing the 

provision that California gasoline and gasoline for export will not be included in the ABT 

program. In order to exclude exported gasoline and California gasoline, refiners must 

keep records to demonstrate that the excluded gasoline was designated for export or as 

California gasoline, and was actually exported or used in California.

While under existing fuel programs (e.g., MSAT2), we precluded importers from 

generating “early” credits (credits generated before a program start date), we are allowing 

importers to generate early credits in the Tier 3 ABT program, consistent with our 

proposal. Importers were previously precluded from generating early credits because 

they generally did not need additional lead time to comply with our fuel standards (as 

they most likely would not be investing in new refining technologies) and we also 

thought it would be difficult for them to establish representative baselines from which 
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early credits could be generated. However, early credit baselines are not a part of the 

Tier 3 program, as discussed above. In addition, commenters noted that while importers 

may not necessarily have to take actions to desulfurize fuel like domestic refiners do, 

these parties may have to pay premiums on obtaining lower sulfur fuel, thus their efforts 

to provide lower sulfur fuel should also be able to generate early credits. Thus, we are 

finalizing provisions allowing importers to generate early credits for sending overcompliant gasoline to the United States prior to January 1, 2017. 

We proposed to limit credit generation to refiners and importers. Under the Tier 2 

gasoline program, we allow refiners who produce gasoline by combining blendstocks 

together or adding blendstocks to previously certified gasoline (refiner-blenders) to 

participate in the in the sulfur ABT program, but do not allow butane blenders who 

comply with the reduced sampling, testing, and reporting requirements to participate in 

the sulfur ABT program.

431

 We are extending these provisions to butane and pentane 

blenders under the Tier 3 program.432 Under today’s rule, any refiner who uses the 

reduced sampling, testing, and reporting provisions for blending butane or pentane into 

gasoline will not be allowed to generate credits. Refiner-blenders who comply with the 

full suite of sampling, testing, and reporting requirements will, however, be allowed to 

generate credits.

We received several comments from ethanol producers and Growth Energy

(representing ethanol producers), who commented that DFE should be subject to an 

annual average sulfur standard and that ethanol producers should be able to participate in 

the ABT program that is available to refiners and importers of gasoline. These 

commenters stated that preventing them from participating in the ABT program would 

provide refiners with pathways to allow delayed adoption of cleaner fuel standards at 

their expense. Some ethanol producers commented that they should be allowed to 

participate in the ABT program as a means of offsetting the additional cost of the 

proposed per-batch sulfur testing and reporting requirements. We also received 

comments from refiners stating that credit generation should be permitted only for 

refiners and importers. 

As in existing EPA fuel programs, we continue to believe that it is not appropriate 

expand the ABT provisions to cover ethanol producers and oxygenate blenders for 

several reasons. First, expanding the ABT program beyond refiners and importers could 

greatly increase the number of parties participating thereby potentially complicating EPA 

compliance assurance activities while having little overall impact on the sulfur credit 

pool. Second, the current ABT program under the Tier 2 gasoline sulfur program, which 

is limited to gasoline refiners and importers, has functioned effectively with few 

compliance irregularities. Third, experience with the unleaded gasoline program suggests 

 

431 The provisions for butane blenders are located in 40 CFR 80.82.

432 See Section V.I. for a discussion of the requirements for pentane blenders.
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widespread abuse and fraud when credits have been allowed to be generated or sold by

parties other than refiners or importers subject to the regulations. Fourth, it would require 

a considerably more complicated compliance structure, including the application of all 

refiner responsibilities to ethanol producers and blenders. Fifth, there is no need for DFE 

producers to generate credits in order to recoup the value for any lower sulfur content of 

their product. The value of any lower sulfur content will be reflected in the market price 

of DFE, similar to the octane value to refiners. Sixth, the sulfur ABT provisions were 

included to ease the burden of compliance for refiners who have to make capital changes 

to their facilities to meet today’s more stringent sulfur standards. In addition to reducing 

the cost of today’s gasoline sulfur program, the ABT provisions allow for an earlier 

effective date of the sulfur standards than would otherwise be possible. Such 

considerations are not applicable to ethanol producers since capital expenditures for 

desulfurization equipment or other equipment will not be needed at their facilities to 

comply with the sulfur standards finalized today.

433

 Finally, overcompliance with the 

per-gallon sulfur cap for DFE is not a valid basis for credit generation. We expect that in 

all cases, the DFE sulfur level will be below the cap. To allow credit generation for these 

parties, we would need to set an additional annual average sulfur standard for DFE at 

some level below 10 ppm and allow credits to be generated for overcompliance with that 

standard. Accordingly, we do not believe it is appropriate to allow ethanol producers or 

blenders to generate sulfur credits under the Tier 3 gasoline sulfur program, and as such, 

we are not finalizing such a provision. The Tier 3 rule prohibits any person downstream 

of the refinery or importer that produced or imported gasoline, CBOB, or RBOB who 

adds oxygenate to such product from including the volume and sulfur content of the 

oxygenate in any compliance calculations for credit generation.

4. Credit Generation and Use

Under the Tier 3 ABT program, the credit generation provisions are nearly the 

same as those under the Tier 2 program. In essence, the Tier 2 program simply continues 

with a lower standard below which credits are generated. Refiners and importers are 

allowed to average within and across companies to meet the standard in the most costeffective manner possible, including generating and using credits. For Tier 3, refiners

and importers can generate credits for overcomplying with the 10 ppm standard on a 

volume-weighted annual average basis beginning January 1, 2017. Credit generation 

periods remain 12 months long and continue to be synchronized with annual compliance 

demonstration periods. The final Tier 3 ABT program provisions for approved small 

refiners and small volume refineries are discussed below in Section V.D.6.

Consistent with our proposal, and to encourage early gasoline desulfurization and 

give the refining industry flexibility to stagger their investments over time, we are also 

 

433 The requirements for ethanol producers finalized today are discussed in Section V.G.4.
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finalizing provisions to allow refiners and importers to generate credits prior to January 1, 

2017 (i.e., early credits).

We proposed an early credit program for overcompliance with the current Tier 2 

30 ppm gasoline sulfur standard from January 1, 2014 through December 31, 2016. 

These early credits were proposed to have a credit life of three years, and could be used 

through December 31, 2019. We also proposed that refiners and importers who 

generated early credits would then have to designate them at the end of the compliance 

year as either Tier 2 credits or Tier 3 early credits, and the credits would have to be used 

in accordance with the designation.

We received several comments on our early credit provisions. Some commenters 

stated that the requirement to designate credits as either Tier 2 or Tier 3 would not 

provide refiners and importers the intended amount of flexibility, as they may not 

necessarily be able to predict if they will need to use those early credits for either Tier 2 

or Tier 3 compliance. Further, commenters were concerned that if more refiners than 

anticipated opt to bank the credits for possible future use at their own refineries, it could 

result in less credits being made available to the market. We also received comments 

both in support of and against the proposed three-year credit life. Some commenters 

stated that they believed that all credits should have a five-year life to provide maximum 

flexibility and more certainty on the availability of credits; while other commenters 

supported the three-year credit life limit, because it would coincide with the end of the 

small refiner/small refinery provisions thus providing more certainty of the benefits of the 

Tier 3 program. Finally, while not proposed, we received many comments requesting 

that EPA clarify what would become of “banked” Tier 2 credits (Tier 2 credits generated 

in 2012 and/or 2013 that were not used before the end of their five-year credit life and 

would have expired when the Tier 3 program began, under the terms of the proposed 

ABT program). Commenters further stated that these credits should not expire, but rather 

should be allowed to receive their full five-year credit life, as they represent actual 

reductions in refinery sulfur levels.

As discussed above, we are finalizing a more flexible approach to the ABT 

program than what we proposed. We believe this will provide for a more seamless 

transition from the Tier 2 to the Tier 3 credit programs and more certainty on credit 

availability.

Consistent with our proposal, refiners and importers may begin generating early 

credits on January 1, 2014, and continue through December 31, 2016. These credits will 

be generated on an annual average basis, from a demonstration that the refiner or 

importer’s annual average gasoline sulfur level is below the current Tier 2 30 ppm annual 

average sulfur standard. We believe this simple early credit approach is possible because 

U.S. gasoline was averaging around 30 ppm as we started developing the Tier 3 program, 

based on compliance data. Since refiners and importers would need to continue to 

comply with the existing Tier 2 sulfur standards during the early credit period, absent 

Tier 3, they would need to maintain this level of performance on an industry average 
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basis. Accordingly, any additional gasoline sulfur reductions beyond 30 ppm will be 

attributed to the proposed Tier 3 program. 

In response to comments received, we are not requiring that credits be designated 

as either Tier 2 or Tier 3 and only used for the program for which they were designated. 

Refiners and importers may use early credits either for ongoing compliance with the Tier 

2 program, or bank them for future compliance with the Tier 3 program (within the limits 

of the credit life restrictions). Essentially, the Tier 2 credit generation provisions simply

continue, and any banked credits generated in 2014 through 2016 that were not used for 

compliance with the Tier 2 standards would be carried over for use in complying with 

Tier 3. We believe that this will allow for more certainty of credit availability before 

refiners must make their Tier 3 investment decisions, thus reducing the cost of the 

program. It will also avoid any incentive for refiners to use up banked Tier 2 credits prior 

to 2017 causing increased in-use sulfur levels and emissions.

Based on our analysis of the Tier 2 credit market for 2012, we believe that there 

will be a balance of 2012 banked credits equivalent to approximately two months of 

compliance, and we anticipate a similar amount (perhaps more) for 2013. Although we 

did not propose to allow for banked 2012 and 2013 Tier 2 credits to be used for 

compliance with the Tier 3 program, we are finalizing this provision for a number of 

reasons. First, the Tier 2 banked credits represent real reductions—refiners and importers 

are currently generating these credits for overcompliance with the Tier 2 gasoline sulfur 

standard. Second, allowing these banked credits to receive their full five-year credit life 

will provide more assurance of the credit availability for trading for those who need them 

to comply with Tier 3 without a large capital investment. As previously explained, this 

will allow for more certainty of credits available far before making Tier 3 investment 

decisions, thus reducing the cost of the program. A lack of certainty in the credit trading 

market could lead to refiners banking more credits than usual for their own use rather 

than allowing these credits to be available in the market for trading. As shown in Chapter 

4.3 of the RIA, refiners tend to hold credits as an insurance policy until they approach the 

end of their credit life. If credit-generating refiners continue with this approach, credits 

generated in 2012 and 2013 will likely be available for purchase in 2017 and 2018 for 

those refiners that may want to rely on them for compliance (along with additional early

credits generated in 2014 through 2016). Finally, as we anticipate that these credits will 

be equal to about four months of compliance, the allowance of 2012 and 2013 banked 

Tier 2 credits makes for a more flexible program by effectively allowing for a small 

amount of additional lead time without adversely affecting the overall benefits of the Tier 

3 program. As discussed previously, this will avoid any incentive for refiners to use up 

banked Tier 2 credits prior to 2017 causing increased in-use sulfur levels and emissions. 

We believe these provisions will allow the Tier 3 program to begin on January 1, 2017, 

with more certainty regarding the availability of credits for those refiners needing (or 

choosing) to defer investment to better align with their existing turnaround/shutdown 

schedules.
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All credits generated before January 1, 2017 will be valid for five years or until 

December 31, 2019, whichever is earlier—no early credits may be used for compliance 

beginning January 1, 2020. Thus, banked Tier 2 credits generated in 2012 and 2013 will 

receive their full five-year life and will not expire at the start of the Tier 3 program. 

However, credits generated in 2015 and 2016 that are unused as of December 31, 2019 

will expire and become invalid. We believe that structuring the early credit program this 

way will offer considerable flexibility to refiners phasing in Tier 3 gasoline sulfur 

controls, while still placing a date at which point the intended sulfur program will be fully

implemented and enforceable—January 1, 2020 (the same date small refiners and small 

refineries must begin complying with the 10 ppm sulfur standard). This will also provide 

a date certain to give auto manufacturers greater confidence for the design of their 

vehicles that all vehicles in-use are running on 10 ppm average fuel. Otherwise, it is 

possible that the greater ease of generating early credits relative to 30 ppm sulfur (as 

opposed to 10 ppm in 2017 and beyond) would allow higher sulfur levels to continue 

well beyond 2019.

Consistent with our proposal, all credits generated beginning January 1, 2017 will 

be for overcompliance with the Tier 3 10 ppm annual average sulfur standard, and will 

have a five-year credit life. We believe five years will give refiners and importers 

sufficient time to use credits generated in previous years while still placing limitations on 

credit life to help with enforcement. Five years is consistent with the Tier 2 ABT 

program, as well as the current credit life and recordkeeping provisions for other 40 CFR 

part 80 fuels programs, and coincides with the applicable statute of limitations for 

violations by parties who generate invalid credits. Credits must be used within five years 

from the year they were generated (regardless of when/if they are traded), otherwise they

will expire and become invalid. For example, credits generated in 2017 can be applied 

towards 2018-2022 compliance, as well as 2017 compliance. After March 31, 2023 

(when reports for the 2022 annual compliance period will be due), credits generated in 

2017 will expire and become invalid. Similarly, credits generated in 2018 can be applied 

towards 2019-2023 compliance, as well as 2018 compliance. After March 31, 2024, 

credits generated in 2018 expire, and so on and so forth.

5. Credit Trading Provisions

We are also finalizing provisions for credit trading in Tier 3 that are identical to 

those under the current Tier 2 program. As in that program, it is possible that sulfur 

credits could be generated by one party, subsequently transferred or used in good faith by

another, and later found to have been calculated or created improperly or otherwise 

determined to be invalid. As in the current Tier 2 program as well as other 40 CFR part 

80 fuel programs, if this occurs, we are requiring that both the seller and purchaser will 

have to adjust their sulfur calculations to reflect the proper credits and either party (or 

both) could be determined to be in violation of the standards and other requirements if the 

adjusted calculations demonstrate noncompliance with the 10 ppm standard.
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Sulfur credits must be transferred directly from the refiner or importer generating 

them to the party using them for compliance purposes. This ensures that the parties 

purchasing them are better able to assess the likelihood that the credits are valid. As 

proposed, we are also finalizing an exception for the case where a credit generator 

transfers credits to a refiner or importer who inadvertently cannot use all the credits. In 

this case, the credits can be transferred a second time to another refiner or importer. 

After the second trade, the credits must be used or they will expire. Allowing a 

maximum of two trades is consistent with other recent fuel programs and we believe it is 

sufficiently flexible while still preserving adequate means for enforcement. While some 

commenters stated that they believe the two-trade maximum is not necessary given the 

fact that credits are only being traded within a small part of industry, we believe that 

unlimited trading could result in an unenforceable program and potentially lead to 

problems with invalid credit trading. Given the widespread use of credit trading between 

different companies under the Tier 2 program despite this provision, there appears to 

already be sufficient flexibility in the program. We received comments requesting that 

we clarify that intra-company trading will continue to be unlimited as it is in the existing 

Tier 2 ABT program. Intra-company trading will in fact remain unlimited, and we have 

added language to the final Tier 3 regulations to clarify this.

There are currently no prohibitions against brokers facilitating the transfer of 

credits from one party to another. Any person can act as a credit broker, regardless of 

whether such person is a refiner or importer, as long as the title to the credits is 

transferred directly from the generating refiner or importer to the using refiner or 

importer. This prohibition on outside parties taking ownership of credits was 

promulgated in response to problems encountered during implementation of the unleaded 

gasoline program, and has since been extended to subsequent fuels rulemakings. We 

continue to believe that maintaining this prohibition will allow for maximum program 

enforceability and consistency with all of our other ABT programs for mobile sources 

and their fuels.

6. ABT Provisions for Small Refiners and Small Volume Refineries

Consistent with our proposal, approved small refiners and small volume refineries 

must comply with the 10 ppm annual average standard by January 1, 2020, which allows 

for an additional three years for compliance. This is the primary form of relief offered to 

small refiners and small volume refineries under the Tier 3 gasoline sulfur program 

(discussed further in Section V.E, below). Approved small refiners and small volume 

refineries may continue to generate credits for overcomplying with the 30 ppm Tier 2 

standard before January 1, 2020. Prior to January 1, 2017, credits generated by small 

refiners and small volume refineries can be traded/sold to non-small refiners for use by 

December 31, 2019, and the credit revenues could be used to help offset their Tier 3 

investments.

When the Tier 3 program begins on January 1, 2017, small refiners and small 

volume refineries may continue to generate credits for overcompliance with the 30 ppm 
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sulfur standard (as they will still be subject to the Tier 2 standards through December 1, 

2019), or they may generate credits for overcompliance with the Tier 3 10 ppm sulfur 

standard. We are finalizing that small refiners and small volume refineries must 

designate their credits as being generated for either the Tier 2 or Tier 3 ABT program, as 

proposed. Credits designated and generated as Tier 2 credits may only be traded with 

other small refiners and small volume refineries (and these credits may only be used for 

compliance through December 31, 2019). However, credits designated and generated as 

Tier 3 credits may be traded with non-small refiners as well. Additionally, from January

1, 2017 through December 31, 2019, if a small refiner’s annual average sulfur level is 

below 10 ppm, they may elect to split the designation and generation of credits between 

both the 10 ppm and 30 ppm standards (without double-counting). For example, in 2017, 

a small refiner with an annual gasoline sulfur average of 8 ppm could generate 20 ppmvolume Tier 2 credits (30 ppm-10 ppm) that could be used by other small refiners and 

small volume refineries, or banked by the refinery for future Tier 2 compliance. This 

small refiner would also generate 2 ppm-volume Tier 3 credits (10 ppm-8 ppm) that 

could be sold to refiners and importers subject to Tier 3, or banked by the refiner for 

future Tier 3 compliance. 

7. Deficit Carryforward

Under the final Tier 3 sulfur program, we are finalizing deficit carryforward 

provisions similar to the existing Tier 2 program, whereby an individual refinery that 

does not meet the 10 ppm standard in a given year may carry a credit deficit forward for 1 

year. Under this deficit carryforward allowance, the refinery will have to make up the 

credit deficit and come into compliance with the Tier 3 sulfur standard the next calendar 

year. We received comments expressing concern that it will be more challenging for 

refineries to make up their credit deficit in one year with a 10 ppm sulfur standard, and 

requesting that the deficit carryforward allowance be extended to two or three years. We 

disagree with these comments primarily because of concerns with the enforceability of 

allowing for a deficit beyond one year. In addition, we believe that an extended deficit 

carryforward will further delay Tier 3 sulfur reductions. While we acknowledge that 

there might be an increased hurdle for some refiners to make up their own credit shortfall, 

we believe the ABT program provides ample opportunity to purchase credits from others. 

However, in recognition of unanticipated circumstances, such as where credits are 

unavailable or are prohibitively expensive such that the refiner could not make up the 

deficit in one year, the Tier 3 hardship provisions provide EPA with the authority to 

allow for extended deficit carryforward, if a refiner’s hardship petition demonstrates that 

it meets the criteria. Thus, we are finalizing that a refiner could carry a deficit forward 

for up to 3 years only in cases of hardship situations, as described below in Section 

V.E.2.
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E. Additional Program Flexibilities

1. Regulatory Flexibility Provisions

a. Small Business Regulatory Flexibility Provisions

We are finalizing several regulatory flexibility provisions for small entities in the 

fuels industry to reduce the burden that the Tier 3 program could have on them. As in 

previous fuel rulemakings, our justification for including provisions specific to small 

businesses is that these entities generally have a greater degree of difficulty in complying 

with the standards compared to other entities.

In developing the Tier 3 gasoline sulfur program, we evaluated the environmental 

need as well as the technical and financial ability of refiners and others in the fuel 

industry to meet the sulfur standards as expeditiously as possible. We believe it is 

necessary and feasible for the vast majority of the program to be implemented in the 

established time frame to achieve the air quality benefits as soon as possible. Based on 

information available from small refiners and others (as discussed further in the 

Regulatory Flexibility Analysis description in Section XII.C), we believe that the 

category of entities classified as small generally face unique circumstances with regard to 

compliance with environmental programs, compared to larger entities. Thus, as 

discussed below, we are finalizing several regulatory flexibility provisions for small 

refiners to reduce the burden that the Tier 3 program could have on them.

Small entities as a category generally lack the resources that are available to 

larger companies to raise capital for investing in a new regulatory program, such as 

shifting of internal funds, securing of financing, or selling of assets. Small entities are 

also likely to have more difficulty in competing for any needed engineering and 

construction resources. This is because the magnitude of their projects tends to be both 

smaller and less profitable for the contracted firms. As such, we are including provisions 

in today’s rule that would provide assistance for small entities in meeting the 10 ppm 

sulfur standards. This proposed approach would allow the overall program to begin as 

early as possible; achieving the air quality benefits of the program as soon as possible, 

while helping to ensure that small entities have adequate time to raise capital for new fuel 

desulfurization equipment or to make any other needed changes. We also believe that 

small business regulatory flexibilities can provide these entities with additional help 

and/or time to accumulate capital internally or to secure capital financing from lenders, 

and could spread out the availability of any needed engineering and construction 

resources in a manner that they are available by the time they are needed.

i. Delayed Standards for Small Refiners

We are finalizing a compliance date of January 1, 2020 for small refiners, 

allowing small refiners to postpone compliance with the Tier 3 program for up to three 

years. Small refiners will have from January 1, 2017 through December 31, 2019 to 
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continue production of gasoline with an average sulfur level of 30 ppm (per the Tier 2 

gasoline sulfur program). This delayed compliance schedule for small refiners is not 

intended as an opportunity for those refiners to increase their production of gasoline with 

sulfur levels greater than 10 ppm, but rather will help small refiners with compliance with 

the program. Since the compliance costs for their competitors may rise during these three 

years and since their gasoline will be sold into the same fungible market, this delay will 

not only provide them more lead time, but also financial support towards later 

compliance. Compliance with the 10 ppm annual average sulfur standard will begin on 

January 1, 2020 for small refiners. Further, as discussed in greater detail in Section 

V.D.5, a small refiner would be allowed to continue using Tier 2 gasoline sulfur credits 

through December 31, 2019 to meet their refinery average 30 ppm sulfur standard.

ii. Refinery Gate and Downstream Caps

During the Small Business Regulatory Enforcement Fairness Act (SBREFA) 

Panel process, small refiners raised the concern that a refinery gate cap of 20 ppm could 

cause problems during a refinery turnaround or an upset because a cap of this level could 

result in a refiner not being able to produce saleable gasoline. The Panel likewise had 

concerns that a downstream cap of 25 ppm may cause problems for small downstream 

entities such as transmix processors and gasoline additive manufacturers. They stated it 

would not be feasible for transmix processors to install desulfurization equipment to 

produce gasoline that meets a 25 ppm sulfur cap. They also stated that such a low sulfur 

cap could preclude certain necessary gasoline additives from the market whose activity 

depends on sulfur containing components. Thus, the Panel recommended that EPA 

assess and request comment on retaining the current Tier 2 refinery gate and downstream 

caps of 80 and 95 ppm, respectively, to help provide maximum flexibility and avoid 

system upsets for the entire refining and distribution system. Further, the Small Business 

Administration (SBA) and Office of Management and Budget (OMB) Panel members 

recommended that EPA propose retaining the 80 ppm and 95 ppm caps. The Panel also 

recommended that, if EPA were to propose caps lower than 80 and 95 ppm, the Agency 

request comment on additional refinery gate and downstream caps that are above 20/25 

ppm but below 80/95 ppm. As discussed above, we proposed options to maintain the 

current 80/95 ppm caps or to lower them to 50/65 ppm and sought comment on a refinery

gate cap of 20 ppm with a downstream cap of 25 ppm. We are retaining the current 

80/95 ppm per-gallon sulfur caps in today’s final rule. For more information on today’s 

final per-gallon sulfur cap provisions and related comments, refer to Section V.C of this 

preamble and Chapter 5 of the Summary and Analysis of Comments document.

b. Small Volume Refinery Provisions

Consistent with our proposal, we are finalizing a compliance date of January 1, 

2020 for small volume refineries. Approved small volume refineries will receive a threeyear delay (January 1, 2017 through December 31, 2019) in meeting the 10 ppm average 

gasoline sulfur standard, similar to the small refiner delay. During the development of 

the Tier 3 rulemaking and throughout the SBREFA process, it became evident that some 
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refineries may experience higher compliance costs on a per-gallon basis than other 

refineries, and in some cases considerably higher. These are refineries owned by a 

refiner/company that would not meet the SBA definition of a small business. In an 

oversupplied gasoline market, these refineries may have difficulty justifying capital 

investments to comply with new standards. In recognition of this concern under the RFS 

program, Congress granted all refineries with a crude oil throughput of less than or equal 

to 75,000 barrels per calendar day (bpcd) additional time to comply. Consistent with this 

allowance, we are including delayed Tier 3 sulfur standards for approved small volume 

refineries. Overall, we believe that these small refineries are disproportionally impacted 

when it comes to their cost of compliance and ability to rationalize the investment costs 

in today’s gasoline market. Giving these refineries additional lead time will allow more 

time to invest in desulfurization technology, take advantage of advancements in 

technology, develop confidence in a Tier 3 credit market as a means of compliance, and

avoid competition for capital, engineering, and construction resources with the larger 

refineries. Credit generation opportunities for approved small volume refineries are 

identical to those for small refiners, as described above in Section V.D. 

A refiner must apply and be approved for small volume refinery status. We are 

finalizing a small volume refinery net crude throughput of less than or equal to 75,000 

bpcd, based on the highest crude throughput for the 2012 calendar year. We received 

comment suggesting that a higher crude throughput (e.g., 90,000 bpcd) would be more 

appropriate, as the refining industry has changed since Congress set the 75,000 bpcd 

throughput limit for small refineries in the RFS program. In analyzing various crude 

throughput maximums between 75,000 and 90,000 bpcd, we do not believe it is 

appropriate or necessary to increase the threshold beyond what was previously set by 

Congress. The 75,000 bpcd limit set by Congress was to recognize those refineries that 

would have difficulty with compliance with a rulemaking (from both a cost and 

feasibility standpoint), raising this limit would go beyond Congress’ intent.

2. Provisions for Refiners Facing Hardship Situations

We are finalizing hardship provisions that are intended to accommodate a 

refiner’s inability to comply with the 10 ppm sulfur standard at the start of the Tier 3 

program, and to deal with unforeseen circumstances that may occur at any point during 

the program. These provisions, which are similar to those in existing fuels programs, are 

available to all refiners, small and non-small, though relief will be granted on a case-bycase basis following a showing of certain requirements; primarily that compliance 

through the use of credits is not feasible. Any hardship waiver granted will not be a total 

waiver of compliance; rather, a hardship waiver will consist of short-term relief that will 

allow a refiner facing a hardship situation to, for example, receive additional time to 

comply. EPA will determine appropriate hardship relief based on the nature and degree 

of the hardship, as presented by the refiner in its hardship application, and on our 

assessment of the credit market at that time. Further, as discussed above in Section 

V.D.7, hardship waivers could grant relief in the form of additional deficit carryforward 

for up to three years, depending on the level of hardship and the status of the credit 
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market. A detailed description of the requirements for applying for a hardship waiver is 

located in the regulations at 40 CFR 80.1625.

We do not anticipate a great need for hardship relief, given the flexibilities offered 

as part of the Tier 3 program and an expected robust credit trading market. Nevertheless, 

we are finalizing hardship provisions in this action as a failsafe for unforeseen 

circumstances, or should credits become scarce or prohibitively expensive.

a. Temporary Waivers Based on Unforeseen Circumstances

We are finalizing a provision to allow for temporary waivers based on unforeseen 

circumstances. EPA would, at our discretion, permit a refiner to seek a temporary waiver 

from the Tier 3 sulfur standards under certain rare circumstances. This waiver provision 

is intended to provide refiners relief in unanticipated circumstances - such as a refinery

fire or a natural disaster (i.e., force majeure) - that cannot be reasonably foreseen now or 

in the near future. Under this provision, a refiner can seek a hardship waiver for relief if 

it can demonstrate that the magnitude of the impact is so severe as to require such an 

extension. A refiner would need to show that: (1) the waiver is in the public interest; (2) 

the nonconformity is unavoidable; (3) it will meet the proposed Tier 3 standards as 

expeditiously as possible; (4) it will make up the air quality detriment associated with the 

nonconforming gasoline, where practicable; and (5) it will pay to the U.S. Treasury an 

amount equal to the economic benefit of the nonconformity less the amount expended to 

make up the air quality detriment. These conditions are similar to those in existing fuels 

regulations, and are necessary and appropriate to ensure that any waivers granted would 

be limited in scope.

Such a request will be based on the refiner’s inability to produce compliant 

gasoline at the affected facility due to extreme and unusual circumstances outside the 

refiner’s control that could not have been avoided through the exercise of due diligence. 

The hardship request will also need to show that other avenues for mitigating the 

problem, such as the purchase of credits toward compliance under the ABT program 

provisions, have been pursued and yet were insufficient or unavailable. In light of other 

flexibilities, including the ABT program, we expect that the need for such requests will 

be rare.

b. Temporary Waivers Based on Extreme Hardship Circumstances

In addition to the provision for short-term relief in extreme unforeseen 

circumstances, we are also finalizing a hardship provision where a refiner may receive a 

hardship waiver based on severe economic or physical lead time limitations of the 

refinery to comply with the Tier 3 standards at the start of the program. A refiner seeking 

such hardship relief under this provision must demonstrate that these criteria were met. 

In addition to showing that unusual circumstances exist that impose extreme hardship in 

meeting the Tier 3 standards, the refiner will need to show that: (1) it has made best 

efforts to comply, including through the purchase of credits; (2) the relief granted under 
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this provision is in the public interest; (3) the environmental impact is acceptable; and (4) 

it has active plans to meet the requirements as expeditiously as possible. We expect that 

hardship relief requests under this provision will mostly be applicable at the beginning of 

the Tier 3 program, when refiners are making their investments to comply. If hardship 

relief under these circumstances is approved, we expect to impose appropriate conditions 

to ensure that the refiner is making best efforts to achieve compliance offsetting any loss 

of emission control from the program. 

We believe that providing short-term relief to those refiners that need additional 

time due to hardship circumstances will help to facilitate the adoption of the overall Tier 

3 program for the majority of the industry. However, we do not intend for hardship 

waiver provisions to encourage refiners to delay planning and investments they would 

otherwise make. Again, because of the flexibilities of the overall Tier 3 program, 

especially the ABT program, we expect the need for additional relief to be rare.

F. Compliance Provisions

This section describes the compliance provisions of today’s program. For the 

most part, the Tier 3 sulfur standards simply reflect a lowering of the current Tier 2 sulfur 

standards. Thus, we are retaining most of the same compliance provisions as the current 

Tier 2 program, with exceptions as noted. However, we also proposed and sought 

comment on several fuel program regulatory streamlining measures, including a broader 

program redesign to streamline the reformulated gasoline and anti-dumping 

regulations.434 As discussed below, some of these streamlining measures will also impact 

the Tier 3 sulfur compliance provisions. 

1. Registration, Reporting, and Recordkeeping Requirements

Registration, recordkeeping, and reporting are necessary to track compliance with 

the Tier 3 standards and the ABT program. 

a. Registration Requirements

Refiners, importers, and anyone acting as a refiner (e.g., a terminal with blending 

or other refining operations) who expects to produce or import gasoline must register 

each of its facilities with EPA by June 1, 2016, or six months prior to producing gasoline 

meeting the Tier 3 standards and/or participating in the credit program. Manufacturers of 

denaturants that are designated as suitable for use in the manufacture of DFE that meets 

federal requirements must also register each of their facilities with EPA by June 1, 2016, 

 

434 For more information on Part 80 regulatory streamlining options, refer to Section VI.
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or six months prior to producing denaturant that is so designated.435 Manufacturers of 

pentane designated as suitable for use by blenders into previously certified gasoline 

(PCG) subject to the Tier 2 program must register each of their facilities with EPA prior 

to manufacturing pentane for such downstream blending.436 Manufacturers of pentane 

for use by blenders of pentane into PCG subject to the Tier 3 program must register each 

of their facilities with EPA by June 1, 2016, or six months prior to producing such 

pentane. After the Tier 3 program begins on January 1, 2017, any non-registered parties 

must register at least three months prior to producing gasoline, participating in the credit 

market, producing denaturant designated as suitable for use in the manufacture of DFE 

that meets federal requirements, or producing pentane for downstream blending into PCG 

under the Tier 3 program. Consistent with the existing registration requirements for 

butane blenders, pentane blenders must comply with the fuel registration requirements 

under the fuel and fuel additives registration program of 40 CFR part 79. Most refiners, 

importers, and ethanol producers and some ethanol denaturant manufacturers are 

currently registered with EPA under other 40 CFR part 80 fuels programs. All 

manufacturers of gasoline additives for use in highway vehicles are already required to be 

registered with EPA under 40 CFR part 79 fuel and fuel additives program. Parties who 

are already registered do not have to register again.

The same basic forms currently being used for existing fuels programs will be 

used for Tier 3 registration. These forms are well known in the regulated community and 

are simple to fill out. Upon receipt of a completed registration form, EPA will issue a 

unique 4-digit company identification number and a unique 5-digit facility identification 

number. As with existing fuels programs, these numbers will be required for all reports 

sent to EPA and for PTDs.

Registrations do not expire and do not have to be renewed; however, registered 

parties are responsible for notifying us of any change to their company or facility

information.

An entity’s registration must include a corporate name and address (including the 

name, telephone number, and e-mail address of a corporate contact person); and, for each 

facility operated by the entity:

 Type of facility (e.g., refinery, import facility, pipeline, terminal, transmix 

facility, etc.)

 

435 As discussed in section V.I. of this preamble, the use of denaturants that are so designated enables DFE 

manufacturers to use streamlined provisions to demonstrate compliance with the Tier 3 sulfur requirements 

for DFE.

436 The provisions for downstream blending of pentane into gasoline described in section VI.A.3. will 

become effective 60 days after the publication of this rule and may be used for gasoline subject to the Tier 

2 program requirements as well as gasoline subject to the Tier 3 program requirements.
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 Facility name

 Physical location

 Name, telephone number, and e-mail address of a corporate contact person

b. Reporting Requirements

Refiners and importers must submit annual reports demonstrating their 

compliance with the Tier 3 standards, and on the generation, use, and transfer of sulfur 

credits at each of its refineries or import facilities. Similar to our other sulfur programs, 

refiners and importers must submit data on individual batches of gasoline (including 

batch volume and sulfur content). Based on our experience with existing gasoline and 

sulfur-based programs, we believe that requiring annual reports and individual sulfur 

batch data provides an effective means of monitoring compliance with the standards and 

the credit program.

Producers and importers of blender grade pentane for use by pentane blenders 

must also submit annual reports that include data on individual batches demonstrating 

compliance with the quality requirements for blender grade pentane and batch volume. 

We proposed that producers and importers of DFE and other oxygenates would be 

required to submit an annual report that includes the total volume of DFE/oxygenate 

produced and an attestation that all batches met the proposed fuel quality requirements. 

We continue to believe that such annual reports are important enforcement and 

compliance assurance mechanism and thus are finalizing the proposed annual reporting 

requirements for oxygenate producers and importers. 

Tier 3 reports will be due annually on March 31, on forms as required by EPA.

c. Recordkeeping Requirements

Similar to current EPA fuels programs, refiners and importers must retain all 

records that demonstrate compliance with the Tier 3 program, including the ABT 

program. 

Manufacturers of DFE and other oxygenates must keep records for five years on 

individual batches of DFE/oxygenate (including batch volume,, denaturant concentration, 

and sulfur test results or other records to demonstrate compliance with the Tier 3 sulfur 

requirements as applicable).437

 

437 As discussed in section V.G. of this preamble, DFE manufacturers may demonstrate compliance with 

Tier 3 sulfur requirements either by testing each batch or mathematically using volumetric blend records 
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Manufacturers of ethanol denaturant that is designated as suitable for use in the 

manufacture of DFE that meets federal requirements must keep records on individual 

batches of such denaturant including batch volume, and sulfur content. 

Manufacturers of pentane that is designated as suitable for use for blending into 

PCG must keep records on individual batches of such pentane including batch volume, 

sulfur content, benzene content, olefin content, aromatic content, C6 and higher 

hydrocarbon content, and purity as applicable.

Manufacturers of gasoline additives for use in highway vehicles must keep 

records on individual batches of such additives including batch volume and additive 

production quality control activities which demonstrate that the sulfur content of additive 

production batches complies with the Tier 3 sulfur requirements. We expect that such 

records would include the results of periodic sulfur testing but not necessarily testing on 

each production batch.

All parties in the gasoline, DFE, ethanol denaturant, pentane, and gasoline 

additive production and distribution system subject to the Tier 3 sulfur program are also 

required to keep records of all PTDs and records of any quality assurance programs. 

Records must be retained for five years. For credit transactions, records must be retained 

for five years from the usage date. Records must be made available to EPA on request; if 

electronic records are kept, hard copies must be made available upon request.

Information submitted to EPA may be claimed as confidential business 

information (CBI). Parties making such a claim must follow all reporting guidance and 

clearly mark the information being claimed as proprietary. EPA will treat information 

covered by such a claim in accordance with the regulations at 40 CFR part 2 and other 

Agency procedures for handling proprietary information.

2. Sampling and Testing Requirements

Under the Tier 2 program, a sulfur concentration must be determined for every

batch of gasoline. We are retaining this requirement under the Tier 3 program. As with 

the existing Tier 2 program, this every-batch testing requirement will be required to occur 

prior to the batch leaving the refinery. We are also retaining the Tier 2 sampling, testing, 

and sample retention requirements in today’s final rule. Additionally, as discussed below 

in Section VI, we have included performance based measurement standards that will 

allow refiners to use alternate test methods for measuring sulfur if they so choose.

We proposed that manufacturers of DFE would be required to test each individual 

batch of DFE for its sulfur content. In response to comments, we are finalizing an 

 

and product transfer documents from the denaturants used provided such denaturants are from a registered 

denaturant producer.
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alternative means for DFE manufacturers to demonstrate compliance with the Tier 3 

sulfur requirements in addition to per batch testing.438 We anticipate that DFE 

manufacturers will typically use this alternative means in the place of per batch sulfur 

testing.

As discussed above, manufacturers of additives for use in highway gasoline 

vehicles must maintain records of additive production quality control activities which 

demonstrate that the sulfur content of additive production batches complies with the Tier 

3 sulfur requirements. We expect that periodic sulfur testing will be needed to comply

with this requirement but not necessarily testing on each additive production batch. 

Manufacturers of pentane that is designated as suitable for use by blenders into PCG must 

test every batch to demonstrate compliance with the requirements sulfur content, benzene 

content, olefin content, aromatic content, C6 and higher hydrocarbon content, and purity

as applicable. Blenders of pentane into gasoline must conduct periodic sampling and 

testing of the pentane they receive from each separate pentane supplier to demonstrate 

that the pentaene is compliant with the applicable compositional requirements.

3. Small Refiner Compliance

To qualify for small refiner status under the Tier 3 program, a refiner must apply

by June 1, 2016. As with our other existing EPA fuels programs, we are continuing to 

use the Small Business Administration definition of a small refiner: 1,500 employees 

(company-wide). To qualify for small refiner status under Tier 3, a small refiner must 

also meet the following additional criteria:

 The refiner must have produced gasoline from crude oil during the 2012 

calendar year.

 The refiner must have owned and operated the refinery during the period from 

January 1, 2012 through December 31, 2012. New owners that purchased a 

refinery after that date will have done so with full knowledge of the proposed 

Tier 3 regulations, and should have planned to comply along with their 

purchase decisions. As with existing fuel programs, a refiner that restarts a 

refinery in the future may be eligible for small refiner status. Thus, a refiner 

restarting a refinery that was shut down or non-operational during calendar 

year 2012 can apply for small refiner status. In such cases, we will judge 

eligibility under the employment and crude oil capacity criteria based on the 

most recent 12 consecutive months prior to the application, unless we 

conclude from data provided by the refiner that another period of time is more 

appropriate. However, this is limited to a company that owned the refinery at 

 

438 The alternative means of demonstrating compliance with the Tier 3 sulfur requirements for DFE 

manufacturers is discussed in section V.G. of this preamble
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the time that it was shut down. New purchasers will not be eligible for small 

refiner status for the same reasons described above.

 The refiner must have had 1,500 employees or less based on the average 

number of employees for all pay periods from January 1, 2012 through 

December 31, 2012 for all subsidiaries, parent companies (i.e., any company

or companies with controlling interest), and joint ventures.

 The refiner must have had a crude oil capacity less than or equal to 155,000 

bpcd during the 2012 calendar year.

A refiner applying for small refiner status must apply and provide EPA with 

several types of information, as specified in the regulations, by June 1, 2016. All refiners 

seeking small refiner status under this program must apply for small refiner status, 

regardless of whether the refiner has been approved for small refiner status under another 

fuel program. As with applications for relief under other rules, applications for small 

refiner status under this final rule that are later found to contain false or inaccurate 

information will be void ab initio.

Requirements for small refiner status applications:

 The total crude oil capacity as reported to the Energy Information 

Administration (EIA) of the U.S. Department of Energy (DOE) for the most 

recent 12 months of operation. This includes the capacity of all refineries 

controlled by a refiner and by all subsidiaries and parent companies and joint 

ventures. We will presume that the information submitted to EIA is correct. 

(In cases where a company disagreed with this information, the company may

petition EPA with appropriate data to correct the record when the company 

submitted its application for small refiner status. EPA will accept such 

alternate data at its discretion.)

 The name and address of each company location where employees worked 

during the 2012 calendar year; and the number of employees at each location 

during this time period. This includes the locations and number of employees 

working at all subsidiaries, parent companies, and joint ventures.

 In the case of a refiner who reactivates a refinery that was either shutdown or 

non-operational from January 1, 2012 through December 31, 2012, the name 

and address of each company location where employees worked since the 

refiner reactivated the refinery and the average number of employees at each 

location for each calendar year since the refiner reactivated the refinery.

 The type of business activities carried out at each location.
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 Contact information for a corporate contact person, including: name, mailing 

address, phone and fax numbers, e-mail address.

 A letter signed by the president, chief operating officer, or chief executive 

officer of the company (or a designee) stating that the information contained 

in the application is true to the best of his/her knowledge and that the 

company owned the refinery as of January 1, 2012.

An approved small refiner that exceeds the employee count or crude capacity 

criteria due to merger with, acquisition by, or the acquisition of another entity will lose its 

small refiner status. In situations where a small refiner loses its small refiner status due 

to merger with a non-small refiner, acquisition of another refiner, or acquisition by

another refiner, we are finalizing provisions that are similar to those in our existing fuels 

programs to allow up to an additional 30 months of lead time to comply with the Tier 3 

program after the disqualifying event, but no later than December 31, 2019.439 This 30 

months of additional lead time will only apply to refineries that were previously subject 

to small refiner relief, as we believe there will be no adverse environmental impact 

because of the pre-existing relief provisions that applied to the small refiner. A refiner 

will also lose its small refiner status if it ceases to process crude oil.

Our intent has been, and continues to be, limiting the small refiner relief 

provisions to a small subset of refiners that are challenged, as discussed above. However, 

it is also our intent to avoid stifling normal business growth. Therefore, an approved 

small refiner who exceeds the employee count or crude oil capacity criteria through 

normal business practices may retain its small refiner status. Further, in the sole case of a 

merger between two approved small refiners, such refiners will be permitted to retain 

their individual small refiner status. Additional financial resources would not typically 

be provided in the case of a merger between two small refiners. Small refiner status for 

the two entities of the merger would not be affected; hence the original compliance plans 

of the two refiners should not be impacted. Moreover, no environmental detriment will 

result from the two small refiners maintaining their small refiner status within the merged 

entity as they would have likely maintained their small refiner status had the merger not 

occurred.

4. Small Volume Refinery Compliance

In the case of small volume refineries, the application process for qualification is 

similar to that of a small refiner. A refiner that is both a small refiner and owns a small 

volume refinery need not apply for small volume refinery status; the small refiner 

application is all that is needed. Small refineries must have a net crude throughput 

 

439 See, for example, 69 FR 39051 (June 29, 2004).
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threshold of no more than 75,000 bpcd based on the highest throughput in calendar years 

2011 or 2012 as the basis for receiving small volume refinery status.

Refiners must include the following in their applications for small volume 

refinery status:

 Proof that the refiner produced gasoline from crude oil during the 2012 

calendar year.

 Proof that the refiner owned and operated the refinery during the period from 

January 1, 2012 through December 31, 2012.

 The refinery’s total crude throughput as reported to EIA for each of calendar 

years 2011 and 2012. Again, we will presume that the information submitted 

to EIA is correct. In cases where a refiner disagrees with this information, the 

refiner may petition EPA with appropriate data to correct the record when the 

refiner submits its application for small volume refinery status. EPA will 

accept such alternate data at its discretion.

 Contact information for a corporate contact person, including: name, mailing 

address, phone and fax numbers, e-mail address.

 A letter signed by the president, chief operating officer, or chief executive 

officer of the company (or a designee) stating that the information contained 

in the application is true to the best of his/her knowledge and that the 

company owned the refinery as of January 1, 2012.

5. Attest Engagements, Violations, and Penalties

In today’s final rule we are retaining the existing Tier 2 requirements for attest 

engagements for generation of both early and standard credits, use of credits, and 

compliance with the proposed program, using the procedures currently used in existing 

EPA fuels programs for attest engagements. The violation and penalty provisions 

applicable to today’s Tier 3 program will be very similar to the provisions currently in 

effect in other gasoline programs as well.

6. Special Fuel Provisions and Exemptions

The following paragraphs discuss several provisions and exemptions from the 

Tier 3 gasoline sulfur standards in special circumstances.

a. Gasoline Used in Military Applications

In both our diesel fuel program and the Tier 2 gasoline sulfur program, we 

provided an exemption for fuel used in tactical military vehicles and nonroad engines and 

equipment with a national security exemption (NSE) from the vehicle and engine 
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emissions standards. Due to national security considerations, some of EPA’s existing 

regulations allow the military to request and receive NSEs for vehicles, engines, and 

equipment from emissions regulations if the operational requirements for such vehicles, 

engines, or equipment warrant such an exemption. Fuel used in these applications is also 

exempt if it is used in tactical military vehicles, engines, or equipment that are not 

covered by an NSE but, for national security reasons (such as the need to be ready for 

immediate deployment overseas), need to be fueled on the same fuel as those with an 

NSE. We are including this exemption in the Tier 3 gasoline program.

b. Gasoline Used in Research, Development, and Testing

Similar to existing EPA fuels programs, we are finalizing provisions to allow for 

requests for an exemption from the Tier 3 standards for gasoline used for research, 

development, and testing purposes (“R & D exemption”). We recognize that there may

be legitimate research programs that require the use of gasoline with sulfur levels greater 

than those allowed under the Tier 3 program. Thus, we are including provisions for 

obtaining an exemption from the prohibition against persons producing, distributing, 

transporting, storing, selling, or dispensing gasoline that does not meet the Tier 3 gasoline 

sulfur standards, where such fuel is necessary to conduct a research, development, or 

testing program.

Parties seeking an R & D exemption must submit an application for exemption to 

EPA that describes the purpose and scope of the program, and the reasons why the 

noncompliant gasoline is necessary. Upon presentation of the required information, an 

exemption may be granted at the discretion of EPA, with the condition that EPA can 

withdraw the exemption in the event the Agency determines the exemption is not 

justified. In addition, an exemption based on false or inaccurate information will be 

considered void ab initio. Gasoline subject to an exemption will be exempt from certain 

provisions of this rule, including the sulfur standards, provided certain requirements are 

met. These requirements include the segregation of the exempt gasoline from nonexempt gasoline, identification of the exempt gasoline on PTDs, and pump labeling.

c. Gasoline for Export

Gasoline produced for export, and that is actually exported for use in a foreign 

country, will be considered exempt from the fuel content standards and other 

requirements of the Tier 3 gasoline sulfur program. In order to exclude exported 

gasoline, refiners must retain records to demonstrate that the gasoline was exported. 

Such gasoline must be designated by the refiner, and the PTD must state that the gasoline 

is for “export only”; otherwise, the gasoline will be considered as intended for use in the 

U.S. and subject to the Tier 3 standards. Gasoline intended for export must be segregated 

from all gasoline intended for use in the U.S. Distributing or dispensing such fuel for 

domestic use will be illegal.
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d. Other Special Provisions and Exemptions

Additionally, in existing EPA fuels programs we have included exemptions for 

racing fuel and for fuel used in the U.S. territories of Guam, American Samoa, and the 

Northern Mariana Islands; we are finalizing such exemptions for the Tier 3 program as 

well.

G. Standards for Oxygenates (Including Denatured Fuel Ethanol) and Certified 

Ethanol Denaturants

The following discussion is focused on the standards finalized today for denatured

fuel ethanol (DFE) because DFE is the predominant gasoline oxygenate currently inuse.440

 These standards also apply to other gasoline oxygenates.441

1. Sulfur Standard

The Tier 2 gasoline requirements include the prohibition on blending gasoline 

with DFE that has sulfur content higher than 30 ppm.442 This requirement reflects the 30 

ppm refinery gasoline average sulfur requirement under the Tier 2 program. Consistent 

with the approach under the Tier 2 program and our proposed 10 ppm refinery average 

sulfur standard for gasoline under the Tier 3 program, we proposed that producers of 

DFE for use by oxygenate blenders would be required to meet a 10 ppm sulfur cap 

beginning January 1, 2017. We proposed requiring DFE producers to test each batch of 

DFE to demonstrate compliance with the sulfur content standard, and to retain and 

provide batch reports to EPA. 

The Renewable Fuels Association (RFA) commented that if EPA were to accept 

current industry practices used to assure that DFE is compliant with the state of

California’s 10 ppm sulfur cap for DFE in place of per-batch sulfur testing and reporting 

there would be no additional burden to ethanol producers in meeting a 10 ppm sulfur 

cap.443 In 2002, RFA conducted an industry survey that demonstrated DFE 

manufacturers were meeting California’s 10 ppm maximum sulfur content requirement. 

Since then, RFA has recommended to the ethanol industry that all DFE meet this 

California requirement and indicated that ethanol producers are adhering to this 

recommendation. Other commenters also stated that DFE manufacturers have been 

producing DFE that complies with California specifications because of logistical 

difficulties in segregating ethanol destined for California from other destinations.

 

440 An importer of biofuels commented that EPA should clarify that the standards for DFE will apply to 

importers as well as domestic producers. The regulations finalized today specifically state that the 

standards for denatured fuel ethanol apply to importers are will as domestic producers of DFE.

441 Public comments supported our proposal to apply the same standards to all gasoline oxygenates.

442 40 CFR 80.385(e).

443 RFA requested regulatory relief from the proposed batch testing and reporting requirements as discussed 

in preamble Section V.G.4. 
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An environmental organization commented that the proposed 10 ppm sulfur cap 

for DFE was necessary to ensure that the Tier 3 program benefits are actually realized. 

Refiners commented that requiring DFE to meet a 10 ppm sulfur cap was essential to 

facilitating their compliance with the Tier 3 gasoline sulfur requirements. In 

demonstrating compliance with the 10 ppm average gasoline sulfur standard finalized 

today, gasoline refiners and importers may adjust the sulfur levels in the gasoline and 

BOBs that they produce/import to account for the downstream addition of ethanol.444 

Therefore, the sulfur level of DFE has a direct effect on the extent of the desulfurization 

measures that a refiner/importer will have to undertake to comply with the gasoline sulfur 

standards finalized today. A refiner commented that if the sulfur standard for DFE was 

left at its current level of 30 ppm, greater capital investments would be needed to adjust 

and lower the sulfur content of other gasoline blending streams to prevent violation of the 

ultimate 10 ppm annual average standard.

Some ethanol producers and Growth Energy (representing ethanol producers) 

commented that DFE should be subject to an annual average sulfur standard and be able 

to participate in the averaging banking and trading (ABT) program that is available to 

refiners and importers of gasoline. Some ethanol producers commented that they should 

be allowed to participate in the ABT program as a means of offsetting the additional cost 

of the proposed per-batch sulfur testing and reporting requirements.

EPA believes that requiring DFE to comply with a 10 ppm sulfur cap is the most 

appropriate means of ensuring that finished gasoline blends attain the sulfur control goals 

of the Tier 3 program. Therefore, today’s rule finalizes a 10 ppm sulfur cap for DFE. 

Because essentially all (if not all) DFE already meets California’s 10 ppm sulfur 

standard, EPA believes that the implementation of a federal 10 ppm sulfur cap for DFE 

would not result in a significant increased burden for ethanol producers.445 Neat ethanol 

produced with standard quality control practices should have negligible sulfur content. 

Denaturants with sufficiently low-sulfur content to facilitate compliance with the 10 ppm 

sulfur cap for DFE are widely available. Allowing DFE to exceed 10 ppm would result 

in the use of higher-sulfur denaturants, thereby increasing gasoline refiner capital costs to 

install desulfurization equipment. As discussed in Section V.D.3 of this preamble, there 

are several reasons why we do not believe that it is appropriate to expand the ABT 

provisions to include ethanol producers and importers. Furthermore, as discussed in 

Section V.G.4, sulfur testing on each batch of DFE will not be required provided that the 

DFE producer or importer demonstrates compliance with the 10 ppm sulfur cap for DFE 

with volumetric blending records, whereas an average standard would require testing of 

 

444 Accounting for the effect of oxygenate added downstream of the refinery or import facility in 

demonstrating compliance with the average gasoline sulfur standard is addressed in regulations finalized 

today at §80.1603(d). See Section V.C. in today’s preamble regarding the sulfur level in DFE that must be 

used by refiners and importers in making this compliance determination. 

445 The potential for additional burden associated with demonstrating compliance with a 10 ppm sulfur cap 

is discussed in Section V.G.4.
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every batch. We anticipate that DFE producers and importers will typically choose to 

demonstrate compliance with the 10 ppm sulfur cap using volumetric blending records 

rather than per-batch sulfur testing. Therefore, we do not anticipate that DFE producers 

and importers will need to install additional sulfur testing equipment as a result of today’s 

rule. Hence, there is no need to extend the flexibility of meeting an annual average sulfur 

standard and participation in the ABT program to ethanol producers and importers to help 

facilitate their compliance as exists for gasoline refiners.446 

Comments were supportive of the proposed January 1, 2017 implementation date 

for standards applicable to DFE. Today’s action requires that importers and 

manufacturers of DFE comply with the standards finalized today beginning January 1, 

2017.

2. Limitation on the Type of Ethanol Denaturant

To limit the variability in DFE composition and the associated potential impact on 

vehicle emissions, we proposed to allow the use of only certified gasoline, gasoline 

blendstocks for oxygenate blending (BOBs), and natural gasoline as denaturants. 

Commenters stated that it would be unnecessary to place additional limits on the types of 

denaturants that could be used beyond those in the ASTM specification for DFE. Groups 

representing refiners stated that EPA had not presented data to support that additional 

limitations on the types of denaturants that can be used (or the allowed concentrations at 

which they may be used) are needed beyond those adopted by ASTM and the State of 

California to address concerns about the potential adverse impacts on vehicle emissions 

performance. The ASTM specification for DFE requires that the only denaturants that 

can be used are gasoline, gasoline blendstocks, and natural gasoline. The State of 

California incorporated the ASTM limits on allowable denaturants into its regulations for 

DFE by reference.447 Thus, both ASTM and the State of California allow the use of 

gasoline blendstocks other than BOBs as denaturants. One refiner stated that DFE 

producers have used refinery gasoline blendstocks such as “light straight run” and “light 

naphtha” as denaturants and that removing this flexibility would increase DFE production 

costs. They noted that access to this flexibility could become more important under a 10 

ppm sulfur cap for DFE. In addition to needing to preserve the flexibility to use a range 

of gasoline blendstocks, ethanol manufacturers stated that EPA should consider the 

possibility of approving denaturants that are not currently allowed under the ASTM 

specification for DFE. One refiner stated that ASTM is the appropriate technical forum 

for the consideration of adding new allowable denaturants.

 

446 See Section V.D.3. of this preamble for additional discussion of why we are not extending the sulfur 

averaging, banking, and trading program to cover DFE manufacturers. 

447 The California Code of Regulations references ASTM D 4806-99 which limits the allowed denaturants 

to gasoline, gasoline components, and natural gasoline.
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EPA continues to believe that it is appropriate to implement additional controls to 

address the potential impact of fuel components in denaturants other than sulfur on 

vehicle emissions. However, we agree with the comments that it is not appropriate to 

implement additional controls on the types of denaturants that may be used beyond those 

currently adopted by ASTM and the State of California at this time. Therefore, in 

response to comments, today’s rule includes the requirement that only gasoline, gasoline 

blendstocks, and natural gasoline may be used to denature DFE.448 This requirement is 

essentially the same as the current ASTM and State of California specifications for the 

type of denaturants that may be used. We will continue to monitor the potential need for 

additional controls on ethanol denaturants, and may revisit this issue in the context of 

setting in-use quality specifications for E85 in the future.449 We will also continue to 

monitor the need for additional denaturants, and when appropriate EPA may undertake a 

future rulemaking to consider allowing their use.

As discussed in Section V.G.4, in order for DFE producers and importers to take 

advantage of streamlined provisions for demonstrating compliance with the 10 ppm 

sulfur cap for DFE, they must only use denaturants from registered producers that have 

been demonstrated as meeting EPA compositional requirements. Denaturants from 

unregistered denaturant producers may be used by DFE producers provided that they test 

each batch of DFE to demonstrate compliance with the 10 ppm sulfur cap for DFE.

3. Limitation on Ethanol Denaturant Concentration

To further limit the potential impact on vehicle emissions of fuel parameters in 

ethanol denaturants other than sulfur, we proposed to limit denaturant concentration in 

DFE to a maximum of 2 volume percent, which translates to 2.5 volume percent 

considering rounding. We also requested comment on alternately adopting the additional 

fuel specifications currently in force for DFE in the State of California. While California 

allows a maximum denaturant content of 5 volume percent consistent with the industry

consensus ASTM International (ASTM) specification for DFE, they also have maximum 

specifications for benzene, olefins, and aromatics as well as sulfur.450

A number of refiners and ethanol manufacturers stated that it was unnecessary to 

limit denaturant concentration beyond the 5 volume percent specified by ASTM. Ethanol 

manufacturers stated that the RFS2 program requirement that DFE contain no more than 

2 volume percent denaturant for Renewable Identification Number (RIN) generation 

purposes already provides a strong incentive to keep denaturant concentration under 2 

 

448 Finished gasoline used as denaturant must be compliant with the applicable EPA requirements. 

449 See Section V.H. for a discussion of potential FFV in-use fuel quality requirements.

450 California Code of Regulations 13 CCR section 2262.9. ASTM International D4806-13a, “Standard 

Specification for Denatured Fuel Ethanol for Blending with Gasolines for Use as Automotive SparkIgnition Engine Fuel”.
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percent.451 However, they stated that the flexibility to have a slightly higher denaturant 

content can be important to ethanol producers. One ethanol producer stated that the 

proposed maximum 2 volume percent cap on denaturant concentration would provide 

insufficient tolerance given that the Alcohol and Tobacco Tax and Trade Bureau requires 

a 1.96 percent minimum denaturant concentration.452 They stated that EPA should 

provide a more reasonable tolerance to avoid inadvertent compliance issues.

A number of refiners stated that the current 5 volume percent maximum on 

denaturant concentration established by ASTM would limit concerns regarding 

components other than sulfur so that they would be unlikely to impact vehicle emissions 

performance. One refiner stated that EPA should adopt the entire California 

specifications for DFE in order to address concerns about potential emissions impacts of 

fuel components in denaturants other than sulfur. They stated that this would not impose 

an additional burden on DFE producers since logistical difficulties in segregating ethanol 

destined for California from other destinations has already caused producers to DFE to 

California specifications. 

Since we are not finalizing benzene, olefin, or aromatics specifications for ethanol 

denaturants like California, we continue to believe that it is appropriate to implement a 

more stringent limit on maximum denaturant concentration to address concerns about the 

potential impact on vehicle emissions of fuel parameters in ethanol denaturants other than 

sulfur. Setting a more stringent limit on denaturant concentration will ensure that 

harmful components such as benzene potentially present in ethanol denaturants are 

adequately diluted in the finished fuel blend. We agree with comments that it is 

appropriate to provide additional flexibility for the allowable denaturant levels that may

be used. Therefore, we are finalizing a 3.0 volume percent maximum on ethanol 

denaturant concentration. This approach provides sufficient flexibility to DFE producers 

while avoiding the need to impose additional testing burdens on denaturant and DFE 

producers (e.g., for benzene and aromatics). We will consider whether additional 

controls may be needed for mid-level ethanol blends and E85 in a later action. 

4. Demonstration of Compliance with the Sulfur Requirements and 

Requirements for Certified Ethanol Denaturants

To demonstrate compliance with the 10 ppm sulfur cap finalized today, we 

proposed that producers and importers of DFE would be required to test the sulfur 

 

451 This RFS2 program provision is covered under the definition of renewable fuel/ethanol in 40 CFR 

80.1401. The volume of denaturant used in excess of 2 volume percent must be subtracted from the total 

volume of DFE for RIN generation purposes.

452 Alcohol and Tobacco Tax and Trade Bureau formulas require a minimum of two parts of approved 

denaturant to 100 parts of ethanol with a minimum of 195 proof ethanol.: 27 CFR Subpart X, Distilled 

Spirits for Fuel Use; ASTM International D4806-13a, “Standard Specification for Denatured Fuel Ethanol 

for Blending with Gasolines for Use as Automotive Spark-Ignition Engine Fuel”.
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content of each batch of DFE they produce. We also proposed that DFE producers would 

be required to provide batch records to EPA on an annual basis. We requested comment 

on whether to require producers of denaturants for use in DFE to register with EPA and 

to demonstrate compliance with a maximum sulfur specification based on the anticipated 

dilution with ethanol. 

Refiners stated that producers of DFE should be subject to requirements similar to 

those for gasoline refiners including batch sampling. However, refiners stated there 

would be no added value in requiring batch reports from DFE producers. Ethanol 

producers currently use certificates of sulfur analysis from denaturant producers and 

volumetric DFE blending records to assure themselves that when a sample of DFE is 

tested by the State of California that it will be found to be compliant with a 10 ppm sulfur 

cap.453 They stated that EPA should accept such records to demonstrate compliance with 

the federal 10 ppm sulfur cap for DFE in place of per-batch sulfur testing on DFE. Under

this approach, ethanol producers would maintain records regarding the denaturant sulfur 

content and the calculations used to determine the sulfur content of the finished DFE. 

Because the sulfur content of neat (un-denatured) ethanol manufactured using industry

standard quality control practices should be negligible, the sulfur content of DFE is 

effectively determined by the sulfur content of denaturant used.454 Ethanol producers 

stated that they would also perform standard quality assurance activities including 

sampling incoming shipments of denaturant for sulfur content on a periodic basis. 

Ethanol producers stated that many DFE production facilities do not have on site 

sulfur testing equipment and the installation of such equipment would represent a 

substantial burden to DFE producers. Ethanol producers stated that they had worked with 

denaturant producers to ensure access to a low-sulfur stream of denaturants, and that it is 

common business practice for denaturant producers to provide them with information on 

the sulfur content of their product. Ethanol producers stated that sulfur test results from 

the ASTM Inter-laboratory Crosscheck Program (ILCP) for DFE illustrate that batch 

reporting for DFE is unnecessary. They noted that the ILCP data shows DFE typically 

has sulfur content of 1 to 5 ppm. 

Ethanol producers stated that requiring denaturant manufacturers to register with 

EPA would limit the number of denaturant suppliers willing to supply the ethanol 

industry. They stated that it is inappropriate to require a natural gasoline producer to 

register in order to supply product for DFE, because they are not required to register in 

order to supply the same product to a gasoline blender.

 

453 The State of California does not rely on industry testing and recordkeeping to help establish compliance 

with their sulfur requirements for DFE, instead choosing to focus on direct testing that they conduct. EPA 

relies on the review of industry records including those associated with tesing conducted by industry as 

well as direct testing conducted by EPA for compliance assurance.

454 Ethanol manufacturers conduct periodic sulfate testing on neat ethanol to ensure that sulfur 

contamination from the manufacturing process is negligible. 
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EPA agrees that is appropriate to finalize requirements for the demonstration of 

compliance with the 10 ppm sulfur cap for DFE that are based on current industry

practices rather than requiring sulfur testing on each batch of DFE.455 We agree that that 

potential contribution to the sulfur content of DFE other than from the addition of 

denaturants can be adequately addressed by the retention of production quality control 

records by the ethanol manufacturer. We agree that it is most appropriate to place the 

primary focus of compliance assurance on the denaturant manufacturers given the 

denaturant typically contributes the majority of the sulfur to the finished DFE. Therefore, 

we are finalizing streamlined provisions that DFE producers and importers may use in 

demonstrating compliance with the 10 ppm sulfur cap for DFE as an alternative to testing 

each batch of DFE for its sulfur content. These streamlined provisions are based on the 

use of denaturant batch sulfur testing conducted by denaturant producers who have 

registered with EPA and certified the denaturant they produce as meeting EPA 

requirements.456 Uncertified denaturants from unregistered denaturant producers may be 

used by DFE producers provided that they test each batch of DFE to demonstrate 

compliance with the 10 ppm sulfur cap for DFE.457

DFE manufacturers that use denaturants that have been certified and designated 

on the denaturant product transfer document (PTD) as suitable for use in the manufacture 

of DFE that meets federal requirements will be able use PTDs for the denaturants used 

and volumetric blending records which show that the denaturant was added at 3.0 volume 

percent or less in demonstrating compliance with the 10 ppm sulfur cap for DFE in lieu 

of per-batch sulfur testing of DFE. The sulfur content of “neat” (i.e. un-denatured) 

ethanol may be assumed to be negligible for the purposes of demonstration of compliance 

using volumetric blending records provided that the DFE manufacturer maintains quality

control records that demonstrate this assumption is justified. Today’s rule also requires 

that DFE manufacturers conduct quality assurance to demonstrate affirmative defenses to 

presumptive liability.

458

 Producers and importers of DFE must initiate a PTD to 

accompany each batch of DFE which states that it meets federal standards. 

Denaturant manufacturers are accustomed to providing certificates of sulfur 

analysis to DFE manufacturers. Therefore, we believe that the requirements finalized 

today for denaturant manufacturers to conduct per-batch sulfur testing, initiate a product 

 

455 Per-batch sulfur testing for other potential oxygenates will be required to demonstrate compliance with 

the 10 ppm sulfur cap. EPA may consider amending the requirements for other potential oxygenates in a 

later rulemaking based on additional information that we might receive.

456 Certified denaturant producers and importers will be required to register with EPA as a certified 

denaturant producer or importer by November 1, 2016, or 60 days before introducing certified denaturant 

into commerce, whichever is earlier. 

457 The limitation on the types of denaturants that may be used and the maximum concentration at which a 

denaturant may be used discussed in Section V.G.2 and 3 would apply regardless of whether a denaturant 

from a registered or non-registered denaturant manufacture are used.

458 Such quality assurance practices include periodic calibration of the denaturant blending equipment to 

ensure that denaturants are not added in excess of 3.0 volume percent.
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transfer document stating that denaturant is suitable for use in manufacturing DFE that 

meets federal requirements, retain records, and register with EPA will not represent a 

substantial new burden. DFE manufacturers who use the mathematical method to 

demonstrate compliance with DFE sulfur requirements must only use certified 

denaturants from registered denaturant manufacturers. Registering with EPA will be a 

one-time act, as will be the necessary modifications to denaturant product transfer 

documents. Thus, the requirement to register with EPA should not be a serious 

impediment for a manufacturer to enter the denaturant supply market. We believe that it 

is necessary to require denaturant manufacturers to register with EPA in order to facilitate 

compliance oversight. EPA needs to be able identify all manufacturers of denaturants in 

order to periodically audit their records, and to recognize potential denaturants in the 

system that are incorrectly designated as a certified denaturant appropriate for use in 

manufacturing DFE that meets federal sulfur requirements. Denaturant manufacturers 

that supply their product to refiners for use in the manufacture of gasoline are not 

required to register with EPA because, unlike the DFE manufacturers, refiners are 

responsible for testing the final gasoline they produce.

As is current practice today, we anticipate that ethanol manufacturers will 

negotiate the specific sulfur level they require from denaturant manufacturers to facilitate 

compliance with the 10 ppm sulfur cap for DFE taking into consideration what level of 

compliance margin a given manufacturer feels is necessary. We believe that it is 

appropriate to allow this practice to continue. We understand that ethanol manufacturers 

currently require denaturant manufacturers to provide a product with a sulfur content of 

120 ppm or less in order to ensure that DFE that contains 5 volume percent denaturant 

can comply with California’s 10 ppm sulfur cap for DFE. Thus, we expect that 

denaturant manufacturers will not need to change the sulfur content of the denaturant 

they manufacture in order to comply with the requirements finalized today.

Manufacturers of certified denaturants used by DFE producers that employ the 

volumetric blending record method in demonstrating compliance with the sulfur 

requirements for DFE must retain per batch sulfur test data on the denaturants they

produce to demonstrate that the sulfur content of the denaturant will not cause the sulfur 

content of DFE to exceed 10 ppm when added to neat ethanol at 3.0 volume percent. The 

sulfur content of the certified denaturant must be stated on the PTD and must be no 

greater that 330 ppm. Any sample of denaturant which is designated as appropriate for 

use in manufacturing DFE that meets federal requirements, that is found by EPA to have 

sulfur content above 330 ppm will be deemed to be noncompliant, and the denaturant 

manufacturer may be liable for the associated penalties. A denaturant with a sulfur 

content of 330 ppm when used at 3.0 volume percent would result in a sulfur content of 

the finished DFE of 10 ppm. Certified denaturant manufacturers may represent the 

denaturant they produce as having a sulfur content of less then 330 ppm on the PTD. In 

such cases, the denaturant batch must not exceed the sulfur content stated on the PTD. 

We continue to believe that annual reports from oxygenate producers are 

important enforcement and compliance assurance tool. Therefore, we are finalizing the 
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requirement that producers and importers of DFE and other oxygenates must register with 

EPA as and oxygenate producer or importer and submit annual reports to EPA that 

include the total volume of DFE/oxygenate produced and an attestation that all batches 

met the proposed fuel quality requirements.459

5. Additional Requirements for Denatured Fuel Ethanol, Ethanol 

Denaturants, and Other Gasoline Oxygenates 

We are finalizing regulatory text to clarify that DFE and other gasoline 

oxygenates must be composed solely of carbon, hydrogen, oxygen, nitrogen, and sulfur. 

Manufacturers of denaturants that are designated as suitable for use in the manufacture of 

DFE that meets federal requirements will also be required to attest that the denaturant is 

composed solely of carbon, hydrogen, oxygen, nitrogen, and sulfur.

Producers and importers of gasoline oxygenates, producers and importers of 

denaturants designated as suitable for manufacturing DFE meeting federal sulfur 

requirements, fuel distributors, and oxygenate blenders will be required to maintain the 

applicable records for 5 years and provide them to EPA upon request. 

H. Standards for Fuel Used in Flexible Fueled Vehicles

Flexible fuel vehicles (FFVs) are vehicles that are capable of operating on both 

gasoline and gasoline blends containing up to 83 volume percent ethanol. Ethanol fuel 

blends that contain from 51 and 83 volume percent ethanol (E51-83) have historically

been referred to as “E85” in reference to the maximum allowed content of denatured 

ethanol assuming a 2 percent denaturant concentration.460 Fuel blends that contain from 

16 to 50 percent ethanol (E16-50) are sometimes referred to as mid-level ethanol blends. 

Both E51-83 and E16-50 are currently used only in FFVs.

Whether FFVs are operating on clear gasoline (E0), E85, or any level of ethanol 

in between, to maintain emission performance the vehicles still need fuel that meets 

certain quality specifications, such as the 10 ppm average gasoline sulfur standard 

finalized today. We anticipate that the use of higher level ethanol blends in FFVs will 

continue to increase in the future as the RFS program continues to be implemented. 

Significant public and private initiatives are also currently underway to expand the use of 

ethanol blender pumps that dispense a variety of ethanol blends for use in FFVs.461 

 

459 Oxygenate producers and importers will be required to register with EPA as an oxygenate producer or 

importer by November 1, 2016, or 60 days before introducing certified denaturant into commerce, 

whichever is earlier. 

460 Industry consensus standards for E51-83 are described in ASTM International D5798-13, “Standard 

Specification for Ethanol Fuel Blends for Flexible-Fuel Automotive Spark-Ignition Engines”.

461 The U.S. Department of Agriculture (USDA) has a program to assist in the funding for the installation 

of as many as 10,000 ethanol blender pumps over the next 15 years in rural areas. Growth Energy has a 

“Blend Your Own Ethanol” program to encourage the installation of ethanol blender pumps. 
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Therefore it is becoming increasingly important that all fuels used in FFVs, not just 

gasoline, meet fuel quality standards. The lack of separate fuel quality standards that 

apply to fuels used in FFVs could act to impede the further expansion of ethanol blended 

fuels, which is important to satisfying the requirements of the RFS program. For these 

reasons, we believe it is important that our gasoline quality standards for not just sulfur, 

but also benzene, Reid Vapor Pressure (RVP), detergency, and compliance with the 

interpretive rule defining the phrase “substantially similar” in CAA section 211(f)(1)462

(i.e., contain only carbon, hydrogen, oxygen, nitrogen, and sulfur) apply to any fuel used 

in an FFV.

Our various standards for gasoline currently apply to any fuel sold for use in 

motor vehicles, which is commonly or commercially known or sold as gasoline. In the 

fuel and fuel additive registration program, the gasoline family includes fuels composed 

of at least 50 percent clear gasoline by volume.463 As a result, our gasoline standards 

currently apply to E16-50 ethanol blends. However, additional regulatory provisions 

could be useful to facilitate compliance assurance if we are to continue to treat such midlevel ethanol blends as gasoline. 

The existing requirement that E51-83 must be substantially similar (sub-sim) to 

the vehicle certification test fuel has provided a limited measure of control over in-use 

E51-83 fuel quality. The finalization of specifications for FFV exhaust emission test fuel 

in today’s action will provide improved clarity regarding what constitutes sub-sim for inuse E51-83. However, these specifications are not sufficient to provide clarity as to what 

is considered sub-sim for E51-83. For example, E51-83 manufactured using only 

gasoline, gasoline blendstocks for oxygenate blending (BOBs), a limited volume of 

butane that meets the standards for downstream blending into gasoline, and denatured 

fuel ethanol that meets the standards finalized today would clearly be sub-sim. However, 

use of natural gasoline may or may not result in an E51-83 blend that is sub-sim. In 

addition to the need for additional clarity regarding what constitutes sub-sim for E51-83, 

standards for sulfur, benzene, and RVP are needed to ensure fuel quality supports the 

attainment of our environmental goals.

At proposal, we sought comment on appropriate regulatory mechanisms to 

implement in-use quality standards for E51-83 and E16-50. We requested specific 

comment on possible approaches, including draft regulations, which were described in 

detail in a memorandum to the docket.464 The draft regulations contained fuel quality

specifications for E51-83 and two options that E51-83 manufacturers could use to 

demonstrate compliance. We sought comment on whether the Agency should continue to 

treat E16-50 as gasoline and on the need to clarify existing regulations on the meaning of 

 

462 73 FR 22277, 22281 (April 25, 2008).

463 40 CFR 79.56(e)(1)(i).

464 Possible Approach to Fuel Quality Standards for Fuel Used in Flexible-Fuel Automotive Spark-Ignition 

Vehicles (FFVs), Memorandum to the docket, Jeff Herzog, April 2013.
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gasoline as any fuel that contains 50 percent or more gasoline. Given that E16-50 can 

only be used in FFVs, we also sought comment on whether to amend the regulations to 

treat E16-50 as an alternative fuel. If EPA were to treat E16-50 as an alternative fuel 

rather than gasoline, we sought comment on whether we should take the same approach 

for E16-50 as detailed in the draft regulations for E51-83 with respect to sulfur, benzene, 

RVP standards, and substantially similar requirements under CAA section 211(f). 

We received comments in support of and against our proposal. The vast majority

of comments supported the need for EPA to promulgate in-use quality standards for these 

higher level ethanol blends. We also received a number of detailed productive comments 

on the draft regulations. A number of stakeholders also expressed their willingness to 

work with EPA to provide supplementary information on issues that were not addressed 

at proposal and not contained in their comments. At this time, we acknowledge that 

additional work is needed on some issues and we note that such work could not be 

accommodated within the timeline for this Tier 3 final rule. Therefore, we are deferring 

final action on these provisions at this time. We will continue to work with stakeholders 

in developing in-use fuel quality standards for higher level ethanol blends following the 

publication of this final rule. Subsequently, we may issue a supplementary proposal prior 

to issuing a final rule if the additional information we receive from stakeholders warrants 

such an action.

I. Sulfur Standards for Purity Butane and Purity Pentane Streams Blended into 

Gasoline

Under the Tier 2 gasoline program, “purity” butane blended into gasoline 

downstream of the refinery is subject to a 30 ppm sulfur cap and other specifications 

regarding its composition.465 This is consistent with the 30 ppm refinery average sulfur 

standard under the Tier 2 program. Today’s action finalizes the proposed 10 ppm sulfur 

cap for purity butane blended into gasoline effective January 1, 2017. This is consistent 

with the Tier 3 10 ppm refinery average sulfur specification finalized today.

As discussed in Section VI.A.4 in today’s preamble, we are finalizing provisions 

to allow “purity” pentane to be blended into gasoline downstream of the refinery that are 

similar to the existing provisions for butane blending. This allowance will become 

effective [INSERT DATE 60 DAYS AFTER PUBLICATION IN THE FEDERAL

REGISTER]. Until December 31, 2016, a 30 ppm sulfur cap will apply to purity 

pentane blended into gasoline consistent with the existing sulfur cap for purity butane 

under the Tier 2 program.466 Beginning January 1, 2017, a 10 ppm sulfur cap will apply

to purity pentane blended into gasoline consistent with the butane sulfur standard 

finalized today.

 

465 40 CFR 80.82.

466 Other requirements regarding the composition of purity pentane will also apply that are similar to those 

for purity butane.
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Butane blenders commented that a significant fraction of butane and pentane 

might be expected to have sulfur content in excess of 10 ppm after the Tier 3 gasoline 

sulfur requirements become effective. To maintain a stable and adequate supply of 

butane and pentane for downstream RVP trimming, butane blenders requested that EPA 

adopt a 10 ppm sulfur average cap with a 30 ppm sulfur cap.467 

Butane and pentane have an inherently low sulfur content that can be made to 

meet a 10 ppm sulfur cap with relatively mild desulfurization techniques. We anticipate 

that butane and pentane suppliers will desulfurize these blendstocks to well below 10 

ppm sulfur as part of their response to the Tier 3 gasoline sulfur requirements. Therefore, 

we believe that allowing butane and pentane used for RVP trimming to exceed a 10 ppm 

sulfur cap would needlessly complicate compliance assurance and defer some of benefits 

of the Tier 3 sulfur requirements.

J. Standards for CNG and LPG

The vehicle emissions standards finalized today are fuel neutral (i.e., they are 

applicable regardless of the type of fuel that the vehicle is designed to use). There 

currently are no sulfur standards for the fuel used in compressed natural gas (CNG) and 

liquid propane gas (LPG) vehicles. We requested comment on whether it is necessary for 

EPA to establish sulfur standards for CNG and LPG to enable them meeting more 

stringent vehicle emissions standards, and whether a 15 ppm sulfur cap similar to that 

established for highway diesel fuel would be appropriate. Comment was also requested 

on whether and how to address the sulfur contribution from odorants and other additives 

used in CNG and LPG. 

We received comments in support of and against EPA establishing sulfur 

standards for CNG and LPG and whether such standards are necessary to enable CNG 

and LPG vehicles to meet the vehicle emissions standards finalized today.

468

 In addition, 

some commenters stated that EPA should not establish new sulfur standards for in-use 

CNG and LPG fuels until additional data is available on current sulfur levels, and the 

feasibility/costs associated with potential additional sulfur controls have been evaluated. 

EPA is deferring finalizing in-use sulfur requirements for CNG/LPG in this final 

rule to provide additional time to work with stakeholders to collect data on current 

CNG/LPG sulfur content, to determine whether additional control of in-use CNG/LPG 

sulfur content is needed, and to evaluate the feasibility and costs associated with potential 

additional sulfur controls. Given that the information currently available suggests already 

low sulfur levels in CNG/LPG, the vehicle emissions standards finalized today will apply

 

467 RVP trimming refers to the practice of adding a limited amount of butane/pentane to previously certified 

gasoline at a terminal so that the finished gasoline is closer to the maximum applicable volatility standard 

(summer or winter) than can be attained at the refinery level.

468 See Chapter 5.8. in the Summary and Analysis of Comments Document that accompanies this rule.
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to CNG/LPG vehicles in addition to vehicles fueled on gasoline, diesel fuel, or any other 

fuel.469 

K. Refinery Air Permitting Interactions

EPA recognized when it proposed the Tier 3 fuel program that it is important to 

the success of the Tier 3 fuel program that refineries be able to obtain air permits, if 

needed, in time to complete the modifications necessary to comply with the proposed 

gasoline sulfur program. Accordingly, to help inform the public and obtain comment on 

this topic, a section of the preamble to the proposed rule presented background 

information on air permitting requirements and programs. That information is not 

repeated in full here. Based on our preliminary assessment of the proposed rule’s 

implications for needed refinery modifications, we estimated at the time of our proposal 

that only a small percentage of refineries would likely need to make modifications that 

would trigger a requirement to obtain air permits. Moreover, we anticipated that these 

permit applications would be processed quickly enough that air permitting would not be a 

significant obstacle to timely compliance with the proposed gasoline sulfur program. We 

continue to anticipate that there will be no such obstacle.

Based on our final assessment, which takes into consideration updated 

information on current refinery configurations and operations and refineries’ future plans 

as well as the requirements and flexibilities in the final Tier 3 fuel program, we believe 

that under the final Tier 3 gasoline sulfur standard from a low of four to a high of nine 

refineries would need major source NSR permits, which includes nonattainment New 

Source Review (NSR) and/or Prevention of Significant Deterioration (PSD) permits. 

This estimate equates to approximately four to eight percent of the 108 refineries 

projected to sell gasoline that will be subject to the Tier 3 standards. The number of 

refineries needing major source NSR permits could be even lower if refineries apply 

emission controls to reduce emissions increases below the significance levels applicable 

to affected pollutants or if they “net out” of NSR for the affected pollutants. As stated 

above, EPA continues to anticipate that permit applications associated with refinery

changes needed to comply with the Tier 3 fuel program will be processed quickly enough 

that air permitting will not be a significant obstacle to timely compliance with the 

gasoline sulfur program.

1. Proposal 

In the proposed rule, we stated our anticipation that the types of changes (both 

physical and operational) that would occur at most refineries would not result in 

sufficient emissions increases to require major NSR permits as a prerequisite for 

completing the needed changes for several reasons: because the emissions increase or the 

 

469 Several commenters provided information on CNG and LPG sulfur levels as discussed in the Summary 

and Analysis of Comments associated with this rule.
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net emissions increase is naturally less than the significant level, because the refinery

installs control technologies on project-affected units to further limit the emissions 

increase, and/or because the refinery “nets out” all or part of the emissions increase. 

However, we anticipated that a small number of refineries had the potential to 

experience emissions increases to meet the proposed gasoline sulfur standard that are 

large enough to trigger major NSR (Nonattainment NSR and/or PSD). This small 

number of refineries would have to obtain a major NSR preconstruction permit prior to 

making these necessary process changes. For any required major NSR permits, the 

associated control technology requirements (BACT and/or LAER) would apply only to 

new or modified units associated with the project and not to units at the refinery that are 

not affected by the project. We did not anticipate that the time frames required for the 

small number of affected refineries to obtain any needed NSR and/or PSD permits would 

present an obstacle to timely compliance with the proposed Tier 3 gasoline sulfur 

requirements.

In the proposal we also discussed a number of concepts that might facilitate more 

expeditious permitting where it is required as a result of refinery changes needed to meet 

the new requirements. That discussion was based primarily on concepts that had arisen 

during the earlier Tier 2 fuel program. That discussion is not repeated here. We invited 

public comment on those concepts. 

2. Updated Assessment of Tier 3 Refinery Changes and Permitting Implications

EPA has updated our refinery-by-refinery assessment of the physical and 

operational changes that are likely to be needed to allow each active refinery in the U.S. 

to produce gasoline that complies with the final Tier 3 fuel specifications. We have also 

assessed the likely effects of those changes on refinery emissions. This updated 

assessment is described in more detail in the final RIA. Using this updated assessment, 

we were able to update our understanding of the potential scope of the major NSR 

permitting requirements refiners might face under the final Tier 3 program. In general, 

our assessment indicates that only a small number of refineries will likely need to make 

modifications of a type and size that would trigger the need for a PSD or nonattainment 

NSR permit. 

In our updated analysis, we adjusted the analysis to reflect the existence of a 

nationwide average, banking, and trading (ABT) program and refined our estimates 

regarding the physical and operational changes that will be required at each refinery (as 

described in the final RIA). The modifications at a given refinery could include revamps 

to existing FCC pre- or post-treatment unit(s) or the installation of a new grassroots posttreatment unit for sulfur reduction. Based on the updated projections of refinery-specific 

changes, we re-estimated the increased demand for energy (i.e., fuel to generate process 

heat, steam, and electricity), hydrogen, and sulfur recovery associated with meeting the 

final Tier 3 standards. Having received no comments suggesting that they should be 

changed, we re-applied the representative industry emission factors for NAAQS 
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pollutants, their precursors, and GHGs for each emitting process and combined them with 

estimates of incremental activity to estimate the emissions changes at each equipment 

unit (or group of similar units) at each refinery. 

We determined upper and lower bounds for emissions increases resulting from 

changes necessary to meet the final Tier 3 gasoline sulfur specification. We did not have 

sufficient detailed information to predict which refineries would find it most profitable to 

generate additional electrical power and hydrogen on site rather than purchasing these 

inputs from external suppliers. If a refinery generates these additional inputs internally

on site, the additional emissions would count towards the significant emissions rates and 

could affect the need for a major NSR permit. To account for these variables, we 

evaluated a high and a low case for each identified scenario. Under the high case, we 

assumed 100 percent internal generation of the additional electrical power and hydrogen, 

and under the low case, 100 percent external generation of the same. We expect 

refineries to actually be somewhere between these two extreme cases in the future. For 

the identified high and low cases, we compared the emissions increase for each pollutant 

at each refinery to the significant emissions increase threshold for that pollutant, taking 

into consideration the current attainment status for each pollutant where the refinery is 

located. 

An important aspect of our analysis is that we assumed that refineries would not 

install new emission controls on affected units for the purpose of staying below the 

significant emissions increase threshold and thereby not triggering major NSR. In 

particular, we did not assume that selective catalytic reduction (SCR) to control NOX

emissions would be applied to new or modified fuel combustion units. This is an 

important assumption that tends to result in overestimates of the number of major NSR 

permits needed for NAAQS-related pollutants. In reality, applying new emission 

controls would be an option that refineries may employ to legally avoid major NSR 

permitting. We also did not assume that refineries would “net out” of NSR by taking 

credit for any emissions reductions occurring within a contemporaneous timeframe, 

including any new emissions reduction projects initiated specifically for the purpose of 

“netting out.” This analysis resulted in a prediction of whether a PSD and/or a 

Nonattainment NSR permit would be needed for each refinery and the pollutants that 

would have to be addressed in those permits, under each of the two scenarios. Only the 

results for the high case are presented here. More detailed results as well as the 

underlying methodology used in the permitting analysis are described in the final RIA for 

this rulemaking. In general terms, we found that for the low case only about one-half the 

number of refineries were estimated to trigger major NSR as were estimated for the high 

case.

We found that under the high case, nine refineries appeared likely to have 

significant emissions increases for one or more pollutants and thus would trigger major 
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NSR.470 This estimate equates to approximately eight percent of the 108 refineries 

projected to sell gasoline that will be subject to the Tier 3 standards. Of these nine 

refineries, we predicted that three refineries would need major source permits for 

NAAQS-related pollutants and their precursors (PSD and/or Nonattainment NSR) and for 

GHGs (results for GHG are discussed below). Thus, we believe that under the final Tier 

3 program only about three refineries may need major NSR air permits to address 

NAAQS pollutants. This number could be lower if those refineries apply pollution 

controls, such as SCR for NOX, to sufficiently reduce the emissions increases to levels 

that are below the applicable pollutant significance level, or if the refineries can achieve 

emissions reductions elsewhere at the facility to “net out” of major NSR. For refineries 

that are required to obtain a major NSR permit for NAAQS pollutants, the permitting 

process is expected to normally take about 9 to 12 months once the permitting authority 

has received a complete application.

All three refineries just described as potentially needing NSR permits for NAAQS 

pollutants are also projected to need PSD permits for GHGs. In addition to these three 

refineries, we estimated that six other refineries may require a PSD permit addressing 

only GHG emissions from new or modified equipment that is part of the project. For 

these nine refineries, BACT would have to be applied for GHG emissions, which we 

expect in most cases would mean that new or modified fuel-burning equipment would 

have to be designed for good energy efficiency. We expect that the types of equipment 

and process technologies that refiners are likely to modify or add to meet the final Tier 3 

standards will generally be sufficient to satisfy BACT requirements for GHG emissions 

in terms of achievability, cost-effectiveness, and energy-efficiency even absent the 

requirement to obtain a permit, meaning that having to demonstrate that BACT is in place 

would not necessitate any shift in project design or cause increased costs. This 

expectation is based on the fact that there are strong economic incentives for refiners to 

design and purchase the most energy-efficient process equipment to minimize the cost of 

production. For example, some of the new or modified equipment expected to be 

involved in refinery projects designed to meet the final Tier 3 standards are fuel 

combustion units (e.g., process heaters). Because fuel cost (direct cost in the case of 

purchased natural gas and opportunity cost in the case of refinery-generated fuel gas) 

represents a significant component of total operating cost for such units, refineries will 

strive to maximize energy efficiency based on available technologies as part of their 

project design. 

In 2010, EPA issued a white paper on available and emerging technologies for 

reducing GHGs from the petroleum refining industry.

471

 This white paper addresses the 

 

470 Because state requirements regarding minor NSR permitting vary and we do not expect minor NSR 

permitting programs to be a significant challenge for refinery modification projects, we did not attempt to 

estimate how many of the remaining refineries might need to obtain minor NSR permits.

471 See “Available and Emerging Technologies for Reducing Greenhouse Gas Emissions from the 

Petroleum Refining Industry,” October 2010, available at http://www.epa.gov/nsr/ghgpermitting.html.
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types of equipment expected to be involved in projects designed to meet the final Tier 3 

fuel standards, including process heaters/boilers, hydrogen plants, and sulfur recovery

units. The identified GHG control technologies for these types of units predominately 

involve opportunities for energy efficiency. Consistent with the findings reported in the 

white paper, our experience to date with GHG permitting at refineries and other similar 

sources supports the application of energy efficient design and operation of affected units 

for meeting BACT requirements, and we do not expect that in the time frame associated 

with Tier 3-related projects, add-on controls would be required. 

For EPA-issued permits and permits issued by state or local agencies under 

delegation, consultation with other federal agencies under the Endangered Species Act 

and consideration of environmental justice will also be required. Significantly, no air 

quality modeling of GHGs will be required, and thus there would be no need to obtain 

extensive input information on meteorology and emissions from other nearby sources. 

Given these differences, we expect that the timeline for obtaining a permit only for GHG 

emissions should be shorter by several months than the timeline for a permit that 

addresses NAAQS pollutants.

On March 22, 2012, the President issued Executive Order 13604 (EO 13604), 

Improving Performance of Federal Permitting and Review of Infrastructure Projects. EO 

13604 states that federal permitting and review processes must provide a transparent, 

consistent, and predictable path for both project sponsors and affected communities, and 

that a number of described elements must be incorporated into routine agency practices to 

provide improvements in the performance of federal permitting processes. 

Under the EO, EPA has adopted a plan identifying the permitting and review 

processes that EPA views as most critical to significantly reduce the aggregate time 

required to make permitting and review decisions on infrastructure projects while 

improving outcomes for communities and the environment, and describing specific and 

measurable actions the agency will take to improve these processes.472 With regard to 

permitting under the Clean Air Act, this plan stated EPA’s intention to issue a guidance 

memorandum by the end of 2012 to apply to PSD permits issued by EPA and by state or 

local agencies with delegated authority from EPA, aimed at clarifying expectations and 

responsibilities regarding the timely processing of permit applications by an EPA 

Regional Office or delegated agency. This memorandum was subsequently issued on 

October 15, 2012.473 EPA Regional Offices serving as the permitting authorities for

refineries making modifications as part of the Tier 3 program will be guided by the 

 

472 The U.S. EPA Plan for Modernizing Federal Permitting and Review Pursuant to EO 13604, August 9, 

2012. http://www.epa.gov/epainnov/pdf/eo-infrastructure-epa-final-plan.pdf

473 Timely Processing of Prevention of Significant Deterioration (PSD) Permits when EPA or a PSDDelegated Air Agency Issues the Permit, Stephen D. Page to Regional Air Division Directors, October 15, 

2012. http://www.epa.gov/region07/air/nsr/nsrmemos/timely.pdf
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memorandum. The memorandum also recommends that other permitting authorities 

consider following the approaches outlined in the memorandum where applicable.

3. Comments and Responses

Several oil industry commenters expressed doubt about whether EPA’s prediction 

of the small number of refineries that would need GHG permits was realistic. 

Commenters generally stated that permits for the modifications needed to comply with 

the Tier 3 requirements should be issued expeditiously. Some industry commenters 

expressed doubt that this would be the case, noting what they characterized as the slow 

pace at which GHG permits have been issued since the requirement for GHG permitting 

became effective. One oil industry commenter suggested that Tier 3-related modifications 

be completely exempt from permitting if they would not increase refinery capacity by

more than 10 percent. No other specific suggestions for streamlining were submitted. 

Environmental groups commented that any efforts to streamline permitting should not 

relax the substantive requirements to get a permit. 

The final rule does not establish any new flexibilities or exceptions to current 

permitting regulations. On an ongoing basis, EPA continues to consider ways to 

streamline the permitting process consistent with CAA requirements and goals. EPA has 

concluded that only a small number of refineries appear to have the potential of triggering 

major source permitting as a result of modifications needed to meet the Tier 3 fuel 

program, given the flexibilities provided by the final program in terms of when 

modifications must be in place in order to achieve compliance. There were no industry

comments that demonstrated a specific reason for concern about permitting implications 

on a broad scale. 

The Response to Comment Document includes a fuller summary of the comments 

on refinery permitting implications and the EPA responses to these comments.

L. Refinery Feasibility

While evaluating the merits of a national gasoline sulfur program to reduce 

emissions and enable future vehicle technologies, we also considered the refining 

industry’s ability to reduce sulfur to 10 ppm on average by January 1, 2017 and the 

associated costs (for more on fuel costs, refer to Section VII.B). Based on information 

gathered from numerous stakeholder meetings and discussions with vendor companies 

that provide the gasoline desulfurization technologies both before and after the proposal, 

as well as the results from our refinery-by-refinery modeling, we believe it is 

technologically feasible at a reasonable cost for refiners to meet the sulfur standards in 

the lead time provided. A summary of our feasibility analysis is presented below. For 

more on our feasibility and cost assessments and the refinery modeling that supports 

them, refer to Chapters 4 and 5 of the RIA. 
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1. Comments Received

We received a number of comments on the proposed rule regarding feasibility and 

lead time. Commenters in the refining industry generally stated that they believe that the 

amount of lead time proposed is not sufficient. These commenters noted concerns that 

the short lead time proposed would drive up costs as there would be unscheduled shutdowns to install and/or revamp equipment to meet the Tier 3 sulfur standard, and would 

not provide enough time for the permitting process. These commenters requested at least 

five years of lead time, and noted that EPA has historically provided at least four years of 

lead time in previous fuels rulemakings. Commenters in the auto industry, as well as 

states and non-governmental organizations (NGOs), encouraged us to finalize the rule as 

soon as possible and to retain the January 1, 2017 start date to harmonize our program 

with California’s LEVIII program and to enable Tier 3 benefits as soon as possible. As 

discussed in more detail below, we believe the amount of lead time provided is sufficient, 

especially given the flexibilities being provided. A complete discussion on the comments 

received with regard to lead time can be found in Chapter 5 of the Summary and Analysis 

of Comments document.

2. Is it Feasible for Refiners to Comply with a 10 ppm Average Sulfur Standard?

Gasoline desulfurization technologies are well known and are readily available. 

Many technologies were demonstrated under Tier 2 and have been further demonstrated 

by current fuel programs in California, Japan, and Europe. Under California’s Phase 3 

Reformulated Gasoline program (CaRFG3), gasoline sulfur is limited to 15 ppm on 

average with a 20 ppm per-gallon cap.474 California reduced their per-gallon cap in 

phases from 60 ppm effective December 31, 2003, to 30 ppm effective December 31, 

2005, to 20 ppm effective December 31, 2011. Actual in-use gasoline sulfur levels, 

however, have been largely constrained by the Predictive Model that California refiners 

are using to demonstrate compliance. As a result, gasoline sulfur levels are lower than 

the CaRFG3 limits. Based on the Predictive Model, California gasoline contained 

approximately 10 ppm sulfur on average in 2010 (9 ppm in the summer and 11 ppm in 

the winter).

Japan currently has a 10 ppm gasoline sulfur cap that took effect in January 2008. 

Europe also has a 10 ppm sulfur cap that has been adopted by the 30 Member States that 

comprise the European Union (EU) and the European Free Trade Association (EFTA) as 

well as Albania and Bosnia-Herzegovina.475 Beijing, China also recently introduced a 10 

 

474 California Air Resources Board. (2008, August 29). The California Reformulated Gasoline Regulations, 

Title 13, California Code of Regulations, Sections 2250-2273.5. Retrieved from 

http://www.arb.ca.gov/fuels/gasoline/082908CaRFG_regs.pdf.

475 Hart Energy Consulting. (2011). International Fuel Quality Center: 2011 Worldwide Fuel Specifications 
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ppm sulfur limit for gasoline.476 These standards are considerably more stringent than the 

10 ppm annual average standard being finalized today because each batch of gasoline 

produced at every refinery must meet the 10 ppm cap. As a result, every refinery must be 

designed to meet this cap regardless of changes in crude oil supply, operation conditions, 

or product mix. We note, however, that many oil refineries outside of the United States 

operate differently from their U.S. counterparts. U.S. refiners have invested more heavily

in fluidized catalytic cracker (FCC) units than the rest of the world to maximize gasoline 

production. Because the FCC unit is responsible for nearly all the sulfur that ends up in 

gasoline, many U.S. refineries may face a bigger challenge in achieving 10 ppm gasoline 

sulfur levels. Even in the U.S., however, the picture is changing. The Annual Energy

Outlook for 2013 produced by the Energy Information Administration supports the view 

that the U.S. demand for diesel fuel is increasing while the demand for gasoline is 

decreasing, starting the process that will make the U.S. more like Europe. Thus, U.S. 

refiners seem to be beginning to move away from relying on the FCC unit as the most 

important refinery unit. For this reason, the challenge of complying with more stringent 

gasoline sulfur control will decrease over time, and we discuss this more at the end of this 

section. 

The review of gasoline sulfur control in California and elsewhere and the future 

trend for gasoline demand support that achieving 10 ppm is feasible. The Tier 3 

requirements are less demanding than those of Europe or Japan. This is because the Tier 

3 sulfur standard is an average standard instead of a cap standard. The accompanying 

Tier 3 cap standard is 80 ppm, which is much higher than the average standard, allows 

individual gasoline batches to vary in sulfur level throughout the year. Complying with 

Tier 3 is also made easier, as compared to California, Europe and Japan, by the ABT 

program which allows refineries with an easy path to compliance with Tier 3 to reduce 

their gasoline sulfur to less than 10 ppm sulfur and generate and sell those credits to 

refineries, which are more challenged by Tier 3. 

3. Can Refiners Meet the January 1, 2017 Start Date?

An adequate amount of lead time is required for the implementation of any

rulemaking. Depending on the level of effort required to comply, more or less lead time 

is also required. In the case of Tier 3, refiners need time to select the technology and the 

vendor that will provide the technology needed for compliance with the fuels standard. 

Next, they need time to arrange an engineering and construction (E & C) contractor 

which will design and oversee the construction of the refinery unit and the time needed to 

obtain the necessary permits and procure the necessary hardware. Next, refiners need 

time to construct the unit. Finally, the refiner needs time to make the necessary unit tieins of the unit with the rest of the refinery and then startup the unit. 

 

476 Article from China.org.cn entitled “Beijing to implement stricter fuel standards”, May 19, 2012, 

retrieved from http://www.china.org.cn/environment/2012-05/19/content_25422404.htm
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This section, along with detailed analysis provided in the RIA, explains that when 

taking into account the time to revamp existing FCC postreater units or build grassroots 

postreater units, tie-in the new or revamped units with the rest of the refinery and 

considering the flexibility offered by the ABT program, refiners will be able to comply 

with the Tier 3 program within the lead time provided. 

a. Time Required to Install Grassroots Units and Revamp Existing Units

The technologies for complying with Tier 3 are well known and well proven. 

Refiners which complied with Tier 2 using FCC naphtha desulfurization technologies 

installed the following units: Axens Prime G+, CDTech’s CDHydro and CDHDS, 

UOP’s ISAL Sinopec’s S-Zorb and Exxon’s Scanfining. Refiners shopped around and 

chose among these various technologies which were largely untested at the time, which 

required us to provide more lead time for Tier 2. Since the Tier 2 sulfur standard began 

to be phased in, nine years have elapsed, and we believe that refiners now have direct 

experience with the installation and operation of these technologies and the vendor 

companies that license them and continue to support their installations onsite. We 

therefore believe that refiners will be able to reach a decision very quickly when 

complying with Tier 3, particularly, because in most cases the refiners will be revamping 

the units already installed for Tier 2 when complying with Tier 3. 

Based on our conversations with refiners, construction companies, vendor 

companies and from published literature, we estimated the time it takes to revamp 

existing postreaters and install grassroots postreaters. To revamp an existing postreater it 

is expected to require up to two years. Installing a grassroots postreater is estimated to 

require three years. Figure A reflects these project completion times showing the various 

major intermediate steps for completing the projects. 
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Figure V.L-1. Estimated Project Lead Time for Revamps and Grassroots Units

0- 3-

6

6-

9

9-

12

12-

15

15-

18

18-

21

21-

24

24-

27

27-

30

30-

33

33-

36

Revam

p

Pre- &

Postreaters

Scoping 

Studies

Process

Design

Permitting

Detailed 

Engineering

Field 

Construction

Start-up / 

Shakedown

Grassroots Postreater

Scoping 

Studies

Process

Design

Permitting

Detailed 

Engineering

Field 

Construction

Start-up / 

Shakedown

Since many of the Tier 3 revamps are expected to be very modest (e.g., change 

out a reboiler or heat exchanger), we believe that the revamping of postreaters could take 

less time than what we estimate in Figure V.L-1. Following EPA held discussions with 

many refiners in 2011 about EPA’s plan to pursue additional sulfur control post-Tier 2 

(Tier 3), refiners began the process of assessing how they would comply. The Tier 3 

proposal was delayed for about a year and it is our understanding from recent discussions 

with vendor companies and some refiners that, during this time, many refiners began 

assessing how they intended to comply with Tier 3. Thus, many refiners likely have 

completed the scoping studies, which involves technology selection, and in the case of 

grassroots units, vendor selection as well (refiners with a particular postreater technology

in most cases are expected to simply revamp the same vendor’s technology, so there is no 

need to select a vendor). If refiners have already completed their scoping studies, we 

estimate that installation of the revamps or grassroots units would be about 3 months 

shorter than the 2 and 3 years, respectively, than we estimate in Figure V.L-1. 

We believe that these project timelines are reasonable in light of past industry 

experiences which show FCC postreaters being installed in refineries in less time than 
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what we estimate. At the Motiva refinery in Port Arthur, TX, a grassroots CDTech 

postreater was designed, constructed and started up in less than 2 years. At two refineries 

in Germany, two Prime G+ units were designed, constructed and started up – one of them 

in two years, and the other in 18 months. As an extreme example, the $3.6 billion dollar, 

180 kbbl/day crude oil expansion at Marathon’s Garyville, LA refinery was designed, 

constructed and started up in 4 years. This project involved construction of 10 major 

refinery units. Since these may be best case examples, we continue to believe the 

projections provided above in Figure V.L-1 are reasonable. In contrast, EPA received 

comments and feedback during meetings from the refining industry suggesting that many

of the steps outlined in Figure V.L-1 could take considerably longer. For example, they 

stated that permits could take 2 years and procurement of vessels, pumps, compressors 

and heaters could take 2 years as well, extending the time needed to complete their 

projects. However, even if this may be true in some situations, the examples above 

highlight that this is not true in all situations. Furthermore, most refineries, as discussed 

in section V.K. will not need to go through any extensive permitting process and as 

discussed below, not all refineries will need to undertake extensive revamps of existing 

units or installation of grassroots units. So once again, we believe the timeline shown is 

reasonable for the vast majority of refineries. Many can complete there actions faster. 

For those that may require a longer timeline, the program flexibilities discussed below 

allow for this within the lead time provided. 

b. Program Flexibility that Extends Lead Time

As discussed in Section V.D, the final Tier 3 program includes an ABT program 

that significantly helps refiners comply with the January 1, 2017 start date. There are 

several provisions of the ABT program that help with respect to any leadtime constraints. 

The ABT program allows for ongoing intra-company and inter-company trading 

nationwide. This will allow some refineries to over-comply with the 10 ppm gasoline 

sulfur standard (in our analysis, we modeled these refineries bringing their gasoline down 

to 5 ppm), allowing other refineries that would otherwise need to install grassroots units 

to not invest and purchase credits instead. This aspect of the ABT program is very

important because our analysis estimates that only one refinery would need to install a 

grassroots hydrotreater whereas without the ABT provisions, there could be as many as 

20 grassroots units. This one aspect has huge implications for leadtime because as 

discussed in the previous subsection, revamps require two years or less whereas 

grassroots FCC postreater units require approximately three years to install. We are 

convinced that this aspect of the ABT program will be utilized to the maximum extent 

possible because refineries revamping their postreaters in lieu of installing grassroots 

postreaters results in the most cost-effective mechanism for meeting the 10 ppm annual 

average standard. 

An important issue to consider is that in order for refiners to opt not to invest in a 

grassroots unit they would have to trust that credits will be available to them. For the 

proposal, we conservatively assumed that refiners would only rely on credits if they could 
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generate them internally. However, for the final rule analysis, we have assessed how the 

sulfur credits were being traded under Tier 2 and found that over half the sulfur credits 

were freely traded between companies (as opposed to only being used within companies), 

and many single-refinery companies had sulfur levels above 30 ppm (single-refinery

companies must purchase credits from other companies). Because credits have a 5-year 

life, we also see in the Tier 2 data that refiners tend to sell credits rather than let them 

simply expire. Refiners may hold them as a contingency, but then sell them prior to their 

expiration. For example, in 2012, 40 percent of the credits traded were generated in 2007 

and were set to expire at the end of 2012. This one quality of the Tier 2 program ensures 

the free access to credits. We designed the Tier 3 credit trading program to work just like 

the Tier 2 credit trading program, thus we are confident that there will be widespread 

trading within and between refining companies. 

A second aspect of the ABT program that helps with leadtime is the provision for 

generating early sulfur credits and banking them for later use. As discussed in Section 

V.D above, this provision allows refineries to reduce their gasoline sulfur to less than 30 

ppm prior to January 1, 2017 and bank the credits for later use. Based on comments that 

we received on the proposed rule, we are allowing Tier 2 credits which are generated 

during the years 2012 and 2013 to also be used to show compliance for Tier 3. This 

effectively extends the early credit generation period for Tier 3 to encompass the years 

2012 to 2016, which is 5 years. Analyzing the 2012 gasoline quality data that refiners 

reported to EPA, we found that gasoline sulfur levels in the U.S. averaged about 26.7 

ppm. Thus, refiners have already begun overcomplying with Tier 2 by 3.3 ppm, and are 

therefore already generating early credits that can be used for Tier 3. If refiners do 

nothing more but continue to overcomply with Tier 2 by 3.3 ppm over the 5 years of 

early credit generation, refiners will have generated enough credits to delay the 

completion of their capital projects by roughly a year. Furthermore since those credits 

generated in 2012 and 2013 will expire in 2017 and 2018 respectively, refiners will have 

an incentive to either use them themselves or trade them in 2017 and 2018. Thus refiners 

that may need to count on them to delay their capital investment are likely to be able to 

have access to them. 

When the extent of the flexibility afforded by the final ABT provisions is fully

understood by refiners, we believe that refiners will generate a lot more early credits with 

their existing gasoline sulfur control units than the 3.3 ppm we observed in 2012. As we 

discussed in our cost analysis, to produce more diesel fuel in response to a greater 

demand for diesel fuel relative to gasoline, refiners are undercutting the swingcut portion 

of FCC naphtha at their refineries.477 This action to shift what historically was blended 

into the gasoline pool to the diesel fuel pool, actually also dramatically reduces the sulfur 

content of the gasoline pool. If the entire swingcut portion of FCC naphtha is undercut to 

 

477 The term swingcut means that this portion of the FCC product pool can be blended into gasoline or 

diesel fuel while still meeting the fuel quality specifications for either fuel regardless of where this 

swingcut is blended. 
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the diesel fuel pool, the amount of sulfur in the gasoline pool is reduced by about 50 

percent. Our cost analysis estimates that at almost one quarter of U.S. refineries, refiners 

are fully undercutting the FCC naphtha to diesel fuel today. At many other refineries, 

refiners are only partially undercutting their FCC naphtha. These refineries will be able 

to reduce the sulfur of their gasoline well below their current levels and generate a large 

number of early credits for Tier 3. Even for the subset of refineries at which the FCC 

naphtha is not being undercut, refiners can assess how much activity or catalyst life is left 

in its FCC postreater catalyst and compare this time with the time to the next turnaround 

when the FCC postreater catalyst is scheduled to be replaced. If there is spare catalyst 

life, the refiner could elect to “turn up” their postreaters to reduce their gasoline sulfur 

levels to under 30 ppm. With this strategy, the refiner would generate early sulfur 

credits. Also, when the refiner replaces the catalyst in its Tier 2 postreater, it can elect to 

do so with a more active catalyst which would allow the refinery to produce gasoline at 

sulfur levels below 30 ppm and generate more early credits for Tier 3. 

Based on the early actions refiners are already taking, or could take, to reduce 

their gasoline sulfur levels, we believe that refiners would be able to reduce their gasoline 

sulfur to as low as 20 ppm, on average. By averaging 20 ppm for 2.5 years prior to 2017, 

refiners would be able to delay completion of all capital investments for Tier 3 until mid 

2019. If we add the 3.3 ppm of credits during 2012, 2013 and first part of 2014, refiners 

would be able to delay completion of all capital investments in Tier 3 until 2020. Thus, 

the early credit provisions will, in-effect, provide nearly 6 years of leadtime for full 

compliance with the fuels program. This will allow ample time for refiners to complete 

their investment and schedule their tie-ins during normal shutdown activities. It 

effectively provides even more lead time than the 5 years that the refining industry

requested in their comments. The delay in the program implementation will also help to 

distribute the demand on the E & C industry over more years ensuring that the E & C 

industry won’t be overwhelmed. 

We are also finalizing a compliance deadline of January 1, 2020 for small refiners 

and small volume refineries (i.e., refineries processing less than or equal to 75,000 net 

barrels per day of crude oil). This will provide approximately 36 of the 108 affected 

refineries with nearly 6 years of lead time; again more than the 5 years that the refining 

industry requested in their comments. We believe that these refiners and refineries are 

disproportionally impacted when it comes to their cost of compliance and ability to 

rationalize investment costs in today’s gasoline market. Giving these refiners and 

refineries additional lead time provides more time to invest in desulfurization technology, 

take advantage of advancements in technology, develop confidence in a Tier 3 credit 

market as a means of compliance, and avoid competition for capital, engineering, and 

construction resources with the larger refineries. Due to the January 1, 2020 compliance 

deadline for small refiners and small volume refineries we estimate that of the 64 

refineries that will ultimately need to revamp (63) their existing hydrotreaters or add a 

grassroots hydrotreater (1) over the course of implementing the Tier 3 program 15 

refineries could wait to take such actions until 2020. Further, as discussed in more detail 

in Section V.E.1, small refiners and small volume refineries can generate early credits 
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(from January 1, 2017 through December 31, 2019) relative to 30 ppm for sale to other 

small refiners/small volume refineries, and relative to 10 ppm for sale to non-small 

refiners. This could provide another pool of early credits for Tier 3 prior to January 1, 

2017 and ongoing credits during the years of 2017, 2018 and 2019.

Despite the flexibility afforded by the ABT program, some refiners have 

expressed concern that should they want or need to rely on credits for compliance, they

may not be able to do so if they cannot be assured that they will be able to acquire the 

necessary credits from other parties when the time comes. This could force them into 

making relatively costly investments that they would otherwise be able to avoid. We 

recognize that this may be a concern, particularly prior to 2020 when the market will be 

in a state of transition. While we cannot guarantee credit availability, and we are 

confident that the program as designed provides ample opportunity for credit generation, 

we do believe that providing the market with at least some basic information on credit 

availability may provide some added assurance and aid in credit market liquidity. 

Consequently, we pledge to work with the refining industry on ways to make information 

on the sulfur credit market more transparent over the period leading up to 2020, 

balancing their need for information with the resource constraints of the Agency. In 

doing so, to protect confidentiality, we will not be able to identify individual company

credit balances or deficits, but would intend to provide an aggregated level of 

information, such as total credit balances for each vintage year, on an annual basis 

leading up to 2020. Because industry has already shown the ability to identify and 

establish the necessary trading relationships under the Tier 2 program, we anticipate that 

they will be able to continue to do so under Tier 3. 

In summary, we believe that the ABT program we are finalizing today provides 

ample flexibility for complying with Tier 3. The averaging provisions will allow refiners 

that only need to revamp their Tier 2 postreaters to generate credits by overcomplying 

with the 10 ppm standard, and in turn allow refineries that otherwise need to install 

grassroots units to comply solely through the purchase of credits. The banking provisions 

also allow refiners to generate early credits, effectively delaying investments for 

compliance to potentially as late as 2020. Finally, the small refiner and small refinery

provisions delay compliance for approximately 36 refineries until 2020, as well as 

generate and trade early credits. We believe that all of these provisions effectively 

address any leadtime concerns. Furthermore, there are additional options available to 

refineries to avoid a noncompliance situation should all these program flexibilities prove 

insufficient. Refineries are permitted to carry a credit deficit for one year as long as they

make it up the following year, and the final rule allows refiners to apply for hardship 

waivers if necessary. In addition, refineries with access to export markets can always 

choose to export fuel until such time as they can bring their desulfurization capacity

online. There is a large and growing gasoline export market from the U.S. already. Such 

exports of higher sulfur gasoline could be offset through imports of compliant gasoline 

such as historically occurred from Europe, which has a 10 ppm sulfur cap on gasoline. 
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c. Impact of Turnaround Timing

We received numerous comments on the proposed January 1, 2017 compliance 

deadline. In their comments to the proposed Tier 3 rulemaking, the oil industry stated 

that EPA must consider and include the time it takes to tie-in the revamps and grassroots 

units in the proposed leadtime. The oil industry urged EPA increase the leadtime for Tier 

3 to 5 years to allow for refiners to make their investments needed to comply with Tier 3 

and tie-in those new investments. In today’s action we are finalizing a compliance 

deadline of January 1, 2017. As previously explained above, various provisions of the 

ABT program effectively provide nearly 6 years of leadtime to complete capital projects. 

We also note that the capital projects do not have to be completed prior to installing the 

necessary tie-ins. We do agree, however, that the need to make tie-ins must be 

considered when assessing the feasibility of leadtime, and in doing so, our analysis shows 

that refiners can comply with Tier 3 within the leadtime provided. This is true not only

because the final rule effectively provides nearly 6 years of leadtime to complete capital 

projects, as described above, but also because the capital projects do not have to be 

completed prior to installing the necessary tie-ins.

When a refiner builds a grassroots unit or some sort of revamp which involves 

new reactor volume or perhaps by adding a splitter, this new capital must be “tied-in” to 

the rest of the refinery. The tie in usually involves connecting a pipe from the existing 

unit to the new capital installed for complying with Tier 3. However, a pipe cannot 

simply be added while the refinery is operating. Instead, the refiner will add the 

necessary pipe for making the tie-in when the refinery is shutdown for regular 

maintenance. The revamp or grassroots unit does not have to be started up at that time. 

Instead, the connection pipe just needs to be added and blocked off with a sealing-type 

valve and a blind flange (essentially a flat piece of steel) is bolted on as a precaution 

against a leaky valve. Once this piping has been added, the refiner can restart its refinery. 

Then when the refiner is ready to complete the tie-in to the completed Tier 3 revamp or 

grassroots unit, the refiner would remove the blind flange and connect a pipe which 

connects the existing part of the refinery to the newly installed grassroots postreater unit 

or revamp postreater subunit. This last step can either occur when the refinery is 

shutdown or still operating. At that point the refiner would only need to open the block 

valve to complete the tie-in of the grassroots unit or revamp to the existing refinery. 

On its webpage, the American Petroleum Institute (API) reports that the average 

time between turnarounds is 4 years when the U.S. refineries perform maintenance on the 

FCC unit.478 This means that on average, 25% of U.S. refineries shutdown to perform 

maintenance on its FCC units each year. Most often, refiners conduct maintenance 

turnarounds on their refineries during the spring when the demand for gasoline and diesel 

 

478 Fact Sheet entitled “Refinery Turnarounds,” American Petroleum Institute (API) webpage: 

http://www.api.org/oil-and-natural-gas-overview/fuels-and-refining/refineries/refinery-turnarounds; 

downloaded June 21, 2013.
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fuel is at their lowest. Thus, refiners will have the years of 2014, 2015 and 2016 to make 

their tie-ins during a regularly scheduled refinery turnaround to be able to comply by

January 1, 2017, thus roughly three-quarters of the tie-ins could occur before the January

1, 2017 compliance date.479 If we superimpose the tie-in issue with the types of 

investments we project will be made for Tier 3, we project that for three-quarters of the 

revamps, refiners will be able to make their tie-ins prior to the January 1, 2017 start date, 

while the other refineries will require until the spring of 2017 to make their tie-ins. As a 

worse-case scenario, if refiners don’t even try to begin making their tie-ins until the 

spring of 2015, they would need the spring of 2015 to the spring of 2018 to complete 

their tie-ins. 

However, regardless of whether we assume that tie-ins begin to occur in 2014 or 

2015, the flexibility afforded by the ABT program will readily enable refiners to 

complete their capital investments and tie-ins and comply with Tier 3 within the lead time 

provided. A more detailed discussion and analysis of Tier 3 compliance considering unit 

construction time, the tie-ins of revamps and grassroots units and availability of credits is 

contained in Chapter 4 of the RIA.

d. Hardship

While we project that there will be plenty of credits available to allow refiners to 

complete their capital investments and tie in the new or revamped unit to the rest of their 

refinery, we are providing another option to refiners as a safety valve in case there is a 

shortfall of credits. Consistent with our proposal, today’s rule contains provisions for a 

refiner to apply for a hardship waiver. Thus, where a refiner cannot complete its project 

by January 1, 2017 and credits are not available or are prohibitively expensive, the refiner 

may file a hardship waiver. Details of our hardship provisions can be found in Section 

V.E.2. 

e. Impact on the Engineering and Construction Industry

As in prior rules, we also evaluated the capability of E&C industries to design and 

build gasoline hydrotreaters as well as performing routine maintenance. Two areas 

where it is important to consider the impact of the fuel sulfur standards are: (1) refiners’ 

ability to procure design and construction services, and (2) refiners’ ability to obtain the 

capital necessary for the construction of new equipment required to meet the new 

gasoline quality specification. We evaluated the requirement for engineering design and 

 

479 Since most refiners have already completed their scoping studies with the vendor companies which 

license the desulfurization technologies, they likely already understand what steps would need to be taken 

to tie-in their revamps and grassroots units with their existing refinery. For this reason, we believe that 

refiners can begin making their tie-ins as soon as the spring of 2014, and perhaps even earlier than that. 

One refiner who owns a number of refineries shared with us that they prepared the tie-ins for Tier 3 when 

they installed their Tier 2 units. 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

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construction personnel in a manner consistent with the Tier 2 analysis, particularly for 

three types of workers needed to implement the refinery changes: front-end designers, 

detailed designers, and construction workers. We developed estimates of the maximum 

number of each of these types of workers needed throughout the design and construction 

process and compared those figures to the number of personnel currently employed in 

these areas. 

The number of job hours necessary to design and build individual pieces of 

refinery equipment and the job hours per piece of equipment were taken from Moncrief 

and Ragsdale.480 Their paper summarizes analyses performed in support of a National 

Petroleum Council study of gasoline desulfurization, as well as other potential fuel 

quality changes. The design and construction factors for desulfurization equipment are 

summarized in Table V-1.

Table V-1 Design and Construction Factors

Gasoline Refiners

Number of New Pieces of Equipment per Refinery 60

Number of Revamped Pieces of Equipment per Refinery 15

Job Hours Per Piece of New Equipmenta

Front End Design 300

Detailed Design 1,200

Direct and Indirect Construction 9,150

a Revamped equipment estimated to require half as many hours per piece of equipment

Refinery projects will differ in complexity and scope. Even if all refiners desired 

to complete their project by the same date, their projects would inevitably begin over a 

range of months. Thus, two projects scheduled to start up at exactly the same time are 

not likely to proceed through each step of the design and construction process at the same 

time. Second, the design and construction industries will likely provide refiners with 

economic incentives to avoid temporary peaks in the demand for personnel. 

Applying the above factors, we projected the maximum number of personnel 

needed in any given month for each type of job. The results are shown in Table V-2. In 

addition to total personnel required, the percentage of the U.S. workforce in these areas is 

also shown, assuming that half of all projects occur in the Gulf Coast. 

 

480 Moncrief, Philip & Ragsdale, Ralph. (2000). Can the U.S. E&C Industry Meet the EPA’s Low Sulfur 

Timetable? Paper presented at NPRA Annual Meeting, March 26-28, 2000. Paper No. AM-00-57.
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Table V-2 Maximum Monthly Demand for Personnel

Front-End 

Design

Detailed 

Engineering

Construction

Tier 3 Gasoline Sulfur Program

Number of Workers 202 809 6,012

Percentage of Current Workforcea11% 9% 4%

a Based on current employment in the U.S. Gulf Coast assuming half of all projects occur in the Gulf Coast

To meet the Tier 3 sulfur standards, refiners are expected to invest $2.0 billion 

between 2014 and 2019 and utilize approximately 250 front-end design and engineering 

jobs and 1,500 construction jobs. The number of estimated jobs required is small relative 

to overall number available in the U.S. job market. As such, we believe that three years, 

plus the additional flexibilities provided, is adequate lead time for refineries to obtain 

necessary permits, secure E&C resources, install new desulfurization equipment, and 

make all necessary retrofits to meet the Tier 3 sulfur standards. For an in-depth 

assessment of stationary source implications, refer to Section V.K. For more on our E&C 

assessment, refer to Chapter 4 of the RIA.

M. Statutory Authority for Tier 3 Fuel Controls

Consistent with our proposal, we are adopting gasoline sulfur controls under our 

authority in section 211(c)(1) of the Clean Air Act. This section gives us the authority to 

“control or prohibit the manufacture, introduction into commerce, offering for sale, or 

sale” of any fuel or fuel additive for use in a motor vehicle, motor vehicle engine, or 

nonroad engine or nonroad vehicle (1) whose emission products, in the judgment of the 

Administrator, cause or contribute to air pollution which may reasonably be anticipated 

to endanger the public health or welfare [section 211(c)(1)(A)] or (2) whose emission 

products will impair to a significant degree the performance of any emission control 

device or system which is in general use, or which the Administrator finds has been 

developed to a point where in a reasonable time it would be in general use were the fuel 

control or prohibition adopted [section 211(c)(1)(B)]. Consistent with our proposal, we 

are finalizing controls on gasoline sulfur levels based on both of the Clean Air Act 

criteria, as described in more detail below.

1. Section 211(c)(1)(A)

Under the first criterion, we believe that emission products of gasoline with 

current levels of sulfur contribute to ambient levels of ozone, particulate matter (PM), 

nitrogen dioxide (NO2), sulfur dioxide (SO2) and carbon monoxide (CO), which are all 

pollutants for which EPA has established National Ambient Air Quality Standards 

(NAAQS). These pollutants are linked with respiratory and/or cardiovascular problems 

and other adverse health impacts leading to increased medication use, hospital 

admissions, emergency department visits, and premature mortality. Approximately 149 
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million people currently live in counties exceeding a NAAQS.481 Motor vehicles also 

emit air toxics, and the majority of Americans continue to be exposed to ambient 

concentrations of air toxics at levels which have the potential to cause adverse health 

effects, including cancer, immune system damage, and neurological, reproductive, 

developmental, respiratory, and other health problems.482 A more detailed discussion of 

the health and environmental effects of these pollutants is included in Section II.B. As 

discussed there, emissions of these pollutants cause or contribute to ambient levels of air 

pollution that are reasonably anticipated to endanger public health and welfare. Control 

of gasoline sulfur to 10 ppm will lead to significant reductions in emissions of these 

pollutants, with the benefits to public health and welfare significantly outweighing the 

costs. 

EPA has evaluated the technical feasibility of achieving these sulfur levels, 

including the cost of the reductions. We have concluded that these reductions are 

feasible in the lead time provided. For more on the feasibility of the fuel standards, refer 

to Section V.L above and Chapter 4 of the RIA.

As discussed in Section III, and further supported by the discussion in Section 

IV.A.6, EPA also evaluated the emissions reductions from pre-Tier 3 vehicles that will be 

achieved by controlling gasoline sulfur level to 10 ppm on average. The 10 ppm sulfur 

standard will provide significant reductions in harmful emissions independent of the 

vehicle standards and these reductions are significant and contribute to the total 

monetized health benefits. Already in 2018, when the emission reductions are almost 

entirely due to the sulfur standards, the Tier 3 program will provide significant benefits. 

We continue to believe that the Tier 3 program will produce benefits to public health and 

welfare whose value significantly outweighs the costs. These reductions can be achieved 

in a manner that is technologically feasible. In sum, EPA concludes that the entire body 

of evidence strongly supports the view that controlling gasoline sulfur to 10 ppm is quite 

reasonable in light of the emissions reductions and benefits achieved, taking costs into 

consideration. For more detail on the costs and benefits of the Tier 3 program, refer to 

Chapter 5 of the RIA. 

Section 211(c)(2)(A) requires that, prior to adopting a fuel control based on a 

finding that the fuel’s emission products contribute to air pollution that can reasonably be 

anticipated to endanger public health or welfare, EPA must consider “all relevant medical 

and scientific evidence available, including consideration of other technologically or 

economically feasible means of achieving emission standards under [section 202 of the 

Act].” EPA’s analysis of the medical and scientific evidence relating to the emissions 

 

481 Data come from Summary Nonattainment Area Population Exposure Report, current as of July 20, 2012 

at: http://www.epa.gov/oar/oaqps/greenbk/popexp.html and contained in Docket EPA-HQ-OAR-2011-

0135.

482 U.S. EPA. (2011) Summary of Results for the 2005 National-Scale Assessment. 

www.epa.gov/ttn/atw/nata2005/05pdf/sum_results.pdf.
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impact from motor vehicle engines, which are impacted by gasoline sulfur, is described 

in more detail in Chapter 6 of the RIA. EPA has also satisfied the statutory requirement 

to consider “other technologically or economically feasible means of achieving emission 

standards under section [202 of the Act].” This provision has been interpreted as 

requiring consideration of establishing emission standards under section 202 prior to 

establishing controls or prohibitions on fuels or fuel additives under section 211(c)(1)(A). 

See Ethyl	Corp.	v.	EPA, 541 F.2d. 1, 31-32 (D.C. Cir. 1976). In Ethyl, the court stated 

that section 211(c)(2)(A) calls for good faith consideration of the evidence and options, 

not for mandatory deference to regulation under section 202 compared to fuel controls. 

Id. at 32, n.66. EPA is also adopting Tier 3 emissions standards for motor vehicles under 

section 202. These standards could not achieve any emission reductions for vehicles 

already in use, while reducing fuel sulfur will achieve large emission reductions for 

vehicles already in use. For new vehicles, the use of 10 ppm average sulfur fuel is an 

essential part of achieving Tier 3 levels while applying an array of advancements in 

emissions control technology to the light-duty fleet. As shown in Section IV.A, we 

believe that achieving the Tier 3 exhaust emission standards will require technological 

improvements such as very careful control of the exhaust chemistry and exhaust 

temperatures to ensure high catalyst efficiency. These technology improvements, which 

are described in greater detail in the RIA (Chapter 1) – improving warm-up and catalyst 

light-off after cold starts and maintaining very high catalyst efficiency – all rely on 10 

ppm sulfur average fuel to achieve the very significant emissions reductions required for 

the fleet to achieve Tier 3 emissions levels.

Achieving Tier 3 emissions standards without a reduction in sulfur to 10 ppm 

levels would only be possible if there were technology improvements significantly above 

and beyond even those mentioned above. EPA cannot identify technology improvements 

that could provide such a large additional increase in emissions control effectiveness, 

across the fleet, above and beyond that provided by the major improvements in 

technology discussed above, without any additional gasoline sulfur control. As discussed 

in Section IV.A.3, the Tier 3 fleet average exhaust emissions standards of 30 mg/mi 

NMOG+NOx will require large reductions of emissions across a broad range of lightduty vehicles and trucks with differing degrees of utility. Specifically, achieving Tier 3 

emissions standards as an average across the fleet will require fleet wide reductions of 

approximately 80%. We believe this means significant reductions from all sectors, with 

the result that there is a need for major reductions from all types of vehicles in the lightduty fleet, including those above as well as most vehicles that are already near, at, or 

below the Tier 3 Bin 30 fleet average standard.

Achieving these reductions presents a major technology challenge and EPA is not 

aware of technology improvements that could provide such large additional increases in 

emissions control effectiveness, across the fleet, above and beyond that provided by the 

major improvements in control technologies expected for use in meeting today’s Tier 3 

standards. Rather, as available test data indicates, in addition to lower gasoline sulfur 

levels, the required reductions are of a magnitude that EPA expects manufacturers to 

employ advances in technology in all of the relevant areas of emissions control – exhaust 
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catalyst technologies, (such as reducing the time to catalyst light off, improving exhaust 

catalyst durability at 120,000 or 150,000 miles and improving efficiency of fully warmed 

up exhaust catalysts), reducing engine out emissions, power train calibration primarily

focused on reducing cold-start NMOG emissions, and on reducing both cold-start and 

warmed-up (running) NOX emissions.

The impact of sulfur reduction on the effectiveness of the available technology

improvements plays such a large role in achieving the Tier 3 emissions standards that it is 

clearly unrealistic to expect that technology would be available, at the 30 ppm sulfur 

standard, to fill the emission control gap left from no sulfur reduction, and still achieve 

the very significant fleet wide reductions needed to meet the Tier 3 fleet average. In 

effect reducing sulfur from 30 ppm to 10 ppm has such a large impact on the ability of 

the technology improvements to achieve Tier 3 emissions levels that absent these sulfur 

reductions there is not a suite of technology advancements available to fill the resulting 

gap in emissions reductions. As also discussed in Section IV.A.6, testing of Tier 2 and 

Tier 3 type vehicles, as well as other information, shows that sulfur has a very large 

impact on the effectiveness of the control technologies expected to be used in Tier 3 

vehicles. Without the reduction in sulfur to a 10 ppm average, the major technology

improvements projected under Tier 3 would only result in a limited portion of the 

emissions reductions needed to achieve Tier 3 levels. For example, without the reduction 

in sulfur from a 30 ppm to 10 ppm average, the technology improvements would not 

come close to achieving Tier 3 levels. In some cases this may result in the same 

effectiveness as the current Tier 2 technology and achieve only approximately Tier 2 

levels of exhaust emissions control. 

As earlier explained, EPA has not identified technology that would achieve the 

average Tier 3 emissions standards, across the fleet, with sulfur at 30 ppm levels, and as a 

result Tier 3 emissions standards would not be technically feasible and achievable. This is 

also the case for levels in-between 30 and 10 ppm, e.g., 20 ppm. The required emissions 

reductions are so large and widespread across the fleet, and the technology challenges are 

high enough, especially for heavier vehicles, that the large increase in emissions that 

would occur even from a higher average sulfur level compared to 10 ppm average would 

lead to an inability for the technology to widely achieve the Tier 3 fleet wide average 

emissions standards. 

Further, as also explained in Section IV.A.6, larger vehicles (the largest LDVs 

and LDT3s, LDT4s and MDPVs) will have greater difficulty achieving cold-start NMOG 

emissions control as a result of today’s emissions standards. (Certifying to a useful life of 

150,000 miles versus the current 120,000 miles will further add to manufacturers’ 

compliance challenge for large light trucks; see Section IV.A.7.c for the useful life 

requirements.) This is based in part on the impact on NMOG emissions of the larger 

engine surface-to-volume ratio and resultant heat conduction from the combustion 

chamber during warm-up. There are also tradeoffs between some cold-start NMOG 

controls and cold-start NOx control. For example, secondary air injection and/or leaner 

fueling strategies improve catalyst light-off for NMOG after a cold-start but also place 
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OSC components in an oxidation state that limits potential for NOx reduction and thus 

often result in higher cold-start NOx emissions. Some applications achieve lower 

NMOG+NOx emissions without the use of secondary air injection by careful calibration, 

changes to the catalyst formulation and balancing of catalyst HC and NOx activity. The 

EPA Prototype Silverado and the developmental Ford Explorer discussed in Section 

IV.A.6.c are specific examples of this approach. Thus, as a result of today’s emissions 

standards these larger vehicles, in addition to needing to reduce NOx emissions to nearzero levels (as is generally the case for all Tier 3 vehicles, as discussed below), these 

trucks may also have additional NMOG reduction challenge. 

2. Section 211(c)(1)(B)

Under the second criterion, we believe that sulfur in gasoline will significantly

impair the emission-control systems expected to be in general use in motor vehicle 

engines designed to meet the Tier 3 emission standards. The Tier 3 fuel sulfur standards 

will restrict gasoline sulfur content to an annual average of 10 ppm beginning in 2017, to 

enable compliance with new emission standards based on the use of advanced emission 

control technology that will be available to Tier 3 vehicles.

Section IV describes the substantial adverse effect of high gasoline sulfur levels 

on the emission-control devices or systems for vehicles and engines meeting the Tier 3 

emission standards. As discussed in Section IV.A.6, sulfur in gasoline inhibits the 

emissions control performance of modern three-way exhaust catalyst systems by

selectively binding with, and in some instances reacting with active sites and coating 

materials. The amount of sulfur retained by the catalyst is primarily a function of its 

operating temperature, the active materials and coatings used within the catalyst, the 

concentration of sulfur oxides in the incoming exhaust gases, and air-to-fuel ratio 

feedback and control by the engine management system. In addition to its interaction 

with catalyst materials, sulfur can also react with the wash-coating itself to form alumina 

sulfate, which in turn can block coating pores and reduce gaseous diffusion to active 

materials below the coating surface. Sulfur also interferes with the ability of OSC 

components to reduce NOX emissions. Water-gas-shift reactions, which are also 

important for NOX reduction over catalysts combining Pd and ceria, can be blocked by

sulfur poisoning and may be responsible for observations of reduced NOX activity over 

Pd/ceria catalysts even with exposure to fairly low levels of sulfur (equivalent to 15 ppm 

in gasoline). 

Operating the catalyst at a sufficiently high temperature under net reducing 

conditions (e.g., air-to-fuel equivalence that is net fuel-rich of stoichiometry) can 

effectively release the sulfur oxides from the catalyst components. Thus, regular 

operation at sufficiently high temperatures at rich air-to-fuel ratios can minimize the 

effects of fuel sulfur levels on catalyst active materials and catalyst efficiency. As

discussed in Section IV.A.6, however, it cannot completely eliminate the effects of sulfur 

poisoning. In current vehicles, desulfurization conditions occur typically at high loads 

when there is a degree of commanded enrichment (i.e., fuel enrichment commanded by
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the engine management system primarily for protection of engine and/or exhaust system 

components). A study of Tier 2 vehicles in the in-use fleet recently completed by EPA 

shows that emission levels immediately following high speed/load operation is still a 

function of fuel sulfur level, suggesting that lower gasoline sulfur levels will bring 

emission benefits unachievable by catalyst desulfurization procedures alone. 483 For 

example, if a vehicle operates on gasoline with less than 10 ppm sulfur, exhaust 

emissions stabilize over repeat FTP tests at emissions near those of the first FTP that 

follows the high speed/load operation and catalyst desulfurization. Continued operation 

on gasoline with 10 ppm average sulfur content or lower is necessary after catalyst 

desulfurization in order to achieve emissions reductions with the current in-use fleet.484 

As also discussed in Section IV.A.6, the emission effects study performed by SGS also 

suggests that negative effects of exposure to a somewhat higher sulfur level (80 ppm in 

this case) are largely reversible for Tier 2 vehicles, and thus, suggests that reducing fuel 

sulfur levels nationwide will bring significant immediate benefits by reducing emissions 

of the existing fleet. Finally, to the extent such conditions do not occur today as part of 

normal driving for vehicles in the in-use fleet, there is no practical way to modify such 

existing vehicles to do so. Thus, reducing fuel sulfur levels has been the primary 

regulatory mechanism to minimize sulfur contamination of the catalyst and ensure 

optimum emissions performance over the useful life of a vehicle and is the only effective 

means for the in-use fleet. 

For Tier 3 vehicles, there are several reasons why regular operation at the high 

exhaust temperatures and rich air-to-fuel ratios necessary for catalyst desulfurization is 

not desirable and may not be possible. The temperatures necessary to release sulfur 

oxides are high enough to lead to thermal degradation of the catalyst over time through 

thermal sintering of active materials. Sintering reduces the surface area available to 

participate in reactions. Additionally, it is not always possible to maintain these catalyst 

temperatures (because of cold weather, idle conditions, light load operation). Also, the 

rich air-to-fuel ratios necessary for sulfur removal can result in increased PM, NMOG 

and CO emissions.

The impact of gasoline sulfur has become even more important as vehicle 

emission standards have become more stringent. Some studies have suggested an 

increase in catalyst sensitivity to sulfur when standards increase in stringency and 

emissions levels decrease.485, 486 Emission standards under the programs that preceded 

 

483 The Effects of Ultra-Low Sulfur Gasoline on Emissions from Tier 2 Vehicles in the In-Use Fleet, EPA420-R-14-002.

484 See Preamble Section IV.A.6.c and Chapter 1 of the RIA (Section 1.2.3.2) for more details on this study 

and its results. 

485 Takei, Y., Kungasa, Y., Okada, M., Tanaka, T. Fujimoto, Y. (2000). Fuel Property Requirement for 

Advanced Technology Engines. SAE Technical Paper 2000-01-2019.

486 Ball, D., Clark, D., Moser, D. (2011). Effects of Fuel Sulfur on FTP NOX Emissions from a PZEV 4 

Cylinder Application. SAE Technical Paper 2011-01-0300. 
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the Tier 2 program (Tier 0, Tier 1 and National LEV, or NLEV) were high enough that 

the impact of sulfur was considered negligible. The Tier 2 program recognized the 

importance of sulfur and reduced the sulfur levels in the fuel from around 300 ppm to 30 

ppm in conjunction with the new emission standards. At that time, very little work had 

been done to evaluate the effect of further reductions in fuel sulfur – especially on in-use 

vehicles that may have some degree of catalyst deterioration due to real-world operation. 

As also shown in Section IV.A.6, there are currently available data from various studies 

and testing on Tier 2 vehicles that indicate that emissions performance is sensitive to 

sulfur levels in gasoline. Specifically, the MSAT studies of Tier 2 vehicles showed the 

emission reduction potential of lower sulfur fuel on Tier 2 and later technology vehicles 

over the FTP cycle. For instance, there was a 48 percent increase in NOx over the FTP 

when gasoline sulfur was increased from 6 ppm to 32 ppm. Further, emissions data from 

testing conducted by EPA on a representative subset of vehicles (after clean-out 

procedures) on 28 ppm and 5 ppm fuel with accumulated mileage, showed Bag 2 NOX

emissions were 47 percent lower on the 5 ppm fuel as compared to 28 ppm fuel. The 

reductions found in these studies are also consistent with the MSAT and Umicore studies 

on Tier 2 vehicles in terms of the magnitude of NOX and HC reductions when switching 

from 28 ppm to 5 ppm fuel. The results of the emission effects study performed by SGS 

and included with API’s comments on the Tier 3 proposal are also consistent with the 

findings of EPA’s Tier 2 in-use study, namely that emissions performance is sensitive to 

fuel sulfur level. In sum, these studies confirm our view that reducing sulfur levels in 

gasoline from current levels to levels in the range of today’s final gasoline sulfur 

standards will be expected to achieve significant reductions in emissions of NOX, 

hydrocarbons, and other pollutants of interest from the in-use fleet. 

The importance of lower sulfur gasoline is also demonstrated by the fact that 

vehicles certified to California SULEV typically certify to higher bins for the federal Tier 

2 program. Light-duty vehicles certified to SULEV under LEV II are more typically 

certified federally to Tier 2 Bin 3, Bin 4 or Bin 5. In particular, non-hybrid vehicles 

certified to California SULEV are not certified to federal Tier 2 Bin 2 emissions 

standards even though the numeric limits for NOX and NMOG are shared between the 

California LEV II and federal Tier 2 programs for SULEV and Bin 2. Confidential 

business information shared by the auto companies indicate that the primary reason is an 

inability to demonstrate compliance with SULEV/Bin 2 emission standards after 

vehicles have operated in-use on gasoline with greater than 10 ppm sulfur and with 

exposure to the higher sulfur gasoline sold nationwide. While vehicles certified to the 

SULEV and Tier 2 Bin 2 standards both demonstrate compliance using certification 

gasoline with 15-40 ppm sulfur content, in-use compliance of SULEV vehicles in 

California occurs after significant, sustained operation on gasoline with an average of 10 

ppm sulfur and a maximum cap of 20 ppm sulfur while federally certified vehicles 

operate on gasoline with an average of 30 ppm sulfur and a maximum cap of 80 ppm 

sulfur. Although the SULEV and Tier 2 Bin 2 standards are numerically equivalent, the 

increased sulfur exposure of in-use vehicles certified under the federal Tier 2 program 

results in a need for a higher emissions compliance margin to take into account the 

impact of in-use gasoline sulfur on full useful life vehicle emissions.
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As further discussed in Section IV.A.6.d, available studies and testing also 

confirm that there is significantly increased sensitivity of exhaust emissions to gasoline 

sulfur by vehicles with exhaust emission control technologies that we expect to be used 

with vehicles complying with today’s Tier 3 emissions studies. Specifically, available 

test data from the Ford Motor Company developmental heavy-light-duty truck and the 

Umicore Autocat 2009 Chevrolet Malibu PZEV show more increases in NOx and 

NMOG+NOx emissions with increased gasoline sulfur than was observed for Tier 2 

vehicles. Similarly, test data from the EPA Tier 3 prototype 2012 Chevrolet Silverado 

heavy-light duty pickup also showed increased NMOG+NOx emissions and one 

exceedance of today’s final Bin 30 exhaust emissions standards. In sum, available test 

data indicate that increasing gasoline sulfur levels from 10 ppm to 30 ppm on vehicles 

meeting Tier 3 standards essentially negated the entire benefit of the advances in 

emissions control technology that were applied to meet Tier 3 developmental goals. 

Because of the resulting need to reach near-zero NOX levels to offset NMOG emissions, 

any significant degradation in NOX emissions control over the useful life of the vehicle 

will likely prevent some if not most larger vehicles from reaching a combined 

NMOG+NOX level low enough to comply with the 30 mg/mi fleet-average standard. 

Any degradation in catalyst performance due to gasoline sulfur will also reduce or 

eliminate the margin necessary to ensure in-use compliance with the Tier 3 emissions 

standards. Thus, the impact of gasoline sulfur poisoning on exhaust catalyst performance 

and the relative stringency of the Tier 3 exhaust emissions standards, particularly for 

larger vehicles and trucks, when considered together make a compelling argument for the 

virtual elimination of sulfur from gasoline. 

As discussed in Section V.B, the average 10 ppm gasoline sulfur standard is 

feasible and is the level that appropriately balances costs with the emission reductions 

that it provides and enables. Not only will a 10 ppm sulfur standard enable vehicle 

manufacturers to certify their entire product line of vehicles to the Tier 3 fleet average

standards, but reducing gasoline sulfur to 10 ppm will better enable these vehicles to 

maintain their emission performance in-use over their full useful life. Higher sulfur 

levels would make it impossible for vehicle manufacturers to meet the Tier 3 standards, 

and would forego the very large immediate reductions from the existing fleet. Reducing 

the sulfur level below 10 ppm would further reduce vehicle emissions and allow the Tier 

3 vehicle standards to be achieved more easily. However, we believe that a 10 ppm 

average standard is sufficient to allow vehicles to meet the Tier 3 standards. Further, as 

discussed in Sections V.B and IX.B there are significant challenges associated with 

reducing sulfur below 10 ppm. 

3. Section 211(c)(2)(B)

Section 211(c)(2)(B) requires that, prior to adopting a fuel control based on a 

significant impairment to vehicle emission-control systems, EPA consider available 

scientific and economic data, including a cost benefit analysis comparing emission-
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control devices or systems which are or will be in general use that require the proposed 

fuel control with such devices or systems which are or will be in general use that do not 

require the proposed fuel control. As described above and in the RIA (Chapter 1), we 

conclude that the emissions control technology expected to be used to meet Tier 3 

standards would be significantly impaired by operation on gasoline with annual average 

sulfur levels greater than 10 ppm. Our analysis of the available scientific and economic 

data can be found below in Section VII. The RIA includes a detailed analysis of the 

environmental benefits of the emission standards (Chapters 6 and 8), an analysis of the 

technological feasibility and cost of controlling sulfur to the levels established in the final 

rule (Chapters 4 and 5), and a cost analysis of the sulfur control and motor vehicle and 

engine emission standards (Chapter 9). Under section 211(c)(2)(B), as just noted, EPA is 

also required to compare the costs and benefits of achieving emission standards through 

emission-control systems that would not be sulfur-sensitive, if any such systems are or 

will be in general use. We have determined that there are not (and will not be in the 

foreseeable future) emission control devices available for general use in motor vehicles 

that can meet the emission standards and would not be significantly impaired by gasoline 

with current gasoline sulfur levels. Emissions cannot be reduced anywhere near the 

magnitude contemplated by the emission standards without the application of the kind of 

emissions control technology discussed in this final rule.

4. Section 211(c)(2)(C)

Section 211(c)(2)(C) of the Clean Air Act requires that prior to prohibiting a fuel 

or fuel additive, EPA establish that such prohibition will not cause the use of another fuel 

or fuel additive “which will produce emissions which endanger the public health or 

welfare to the same or greater degree” than the prohibited fuel or additive. This finding 

is required by the Act only prior to prohibiting a fuel or additive, not prior to controlling a 

fuel or additive. Since EPA is not prohibiting use of gasoline sulfur, but rather is 

controlling the level of sulfur in these fuels, this finding is not required for this 

rulemaking. However, EPA does not believe that the gasoline sulfur controls will result 

in the use of any other fuel or additive that will produce emissions that will endanger 

public health or welfare to the same or greater degree as the emissions produced by 

gasoline with current sulfur levels. Unlike the case of unleaded gasoline in the past, 

where lead performed a primary function by providing the necessary octane for the 

vehicles to function properly, sulfur does not serve any useful function in gasoline. It is 

not added to gasoline, but occurs naturally in the crude oil into which gasoline is 

processed. Were it not for the expense of sulfur removal, it would likely have been 

removed from gasoline years ago in order to improve the maintenance and durability 

characteristics of motor vehicle engines. 

We are also adopting the various controls for DFE, other oxygenates, butane and 

pentane blended into gasoline, and gasoline additives, under our authority in section 

211(c)(1). As explained above, these controls are necessary to prevent emissions 

products that may endanger the public health or welfare or impair to a significant degree 

the performance of any emission control device or system. This action basically extends 
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various controls on gasoline to DFE, other oxygenates, butane, and gasoline additives. 

The reasons for adopting the controls for gasoline apply as well to adopt the controls for 

DFE, other oxygenates, butane, and gasoline additives. 

VI. Technical Amendments and Regulatory 

Streamlining

In addition to adopting new Tier 3 vehicle standards and new gasoline sulfur 

standards, we are also finalizing a range of technical amendments and regulatory

streamlining actions as part of the Regulatory Review initiative. Some of these may have 

some bearing on implementation of the Tier 3 vehicle and fuel standards, while others 

deal with other aspects of EPA’s existing fuel and vehicle regulations.

EPA is also synchronizing several different reporting deadlines under various 

regulations affecting transportation and motor vehicle fuels and fuel additives. This 

action will reduce regulatory burdens by aligning reporting deadlines across several 

programs and lays the foundation for the overall goal of combining various fuels reports 

together into a single, simplified electronic format in the near future. 

A. Fuel Program Amendments

The following sections discuss the changes being finalized today to the fuels 

regulations in 40 CFR parts 79 and 80. Some of these changes are technical amendments 

to correct minor errors or inconsistencies in the regulations; others are to address areas in 

the regulations that needed clarification and/or streamlining; still others are to provide 

additional flexibility. 

With regard to regulatory streamlining, the majority of these items involve 

providing additional clarity, removing or updating outdated provisions, and decreasing 

the frequency and/or volume of reporting burden where data are either no longer needed 

or are redundant in light of other EPA fuels programs. In general, we believe that these 

changes are straightforward and will reduce burden on industry with no expected 

environmental impact. 

We are also finalizing regulations to adopt a performance-based measurement 

systems approach to fuel parameter testing as discussed in Section VI.A.2, to expand the 

downstream butane blending provisions to allow for pentane blending as discussed in 

Section VI.A.3, and to accept Top Tier test data under the gasoline deposit control 

program as discussed in Section VI.A.4. We may undertake additional regulatory

streamlining in a future action following additional stakeholder interactions, as discussed 

in Section VI.A.5.

Below is a table listing the provisions that we are amending in today’s action. We 

have provided additional explanation for those amendments that warrant additional 

explanation in the following sections.
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Table VI-1 Summary of Regulatory Streamlining and Technical Amendments

Section Description

Varied Various sections amended to update references to test methods 

(see Section VI.A.1.a.iii).

79.5 Revised periodic reporting requirements.

80.2 Revised and added definitions.

80.8 Amended to update sampling test methods, and to state to 

which fuels §80.8 applies.

80.46 Revised measurement of RFG fuel parameters.

80.47 Added Performance-Based Test Method Approach.

80.65 Amended to reduce complex model test parameters and 

reporting and to accommodate RVP adjustment when blender 

grade pentane is blended into gasoline downstream of the 

refinery.

80.65(f)(5) Added to allow for designation of an alternative lab.

80.66(f) Amended to delete references to appendices that no longer 

exist.

80.74 Amended to reflect the recordkeeping requirements for entities 

in the blender grade pentane distribution system.

80.75 Revised RFG reporting requirements. Added reporting 

requirements for produces and importers of blender grade 

pentane. 

80.77 Amended to reflect the product transfer document requirements 

for entities in the distribution system for blender grade pentane.

80.80 Amended to reflect the potential penalties requirements for 

entities in the distribution system for blender grade pentane.

80.82 Amended to apply butane blending provisions to entire part 80 

and to revise RVP test method.

80.85 Added the requirements for downstream pentane blending.

80.86 Added the requirements for producers and importers of blender 

grade pentane.

80.87 Added the controls and prohibitions for entities in the blender 

grade pentane distribution system.

80.101 Revised measurement of conventional gasoline fuel parameters.

80.105 Amended to require identification of test methods used in 

refiner reports, and to add reporting requirements for butane 

blenders.

80.161(b)(1)(ii)(A)(2) Amended to specify the requirements for certification of an 
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additive under the new alternative gasoline deposit control 

certification option.

80.161(b)(1)(ii)(A)(3) Added to specify the requirements for certification of an 

additive under all gasoline deposit control options other than 

the alternative certification option. 

80.161(b)(2) Amended to address the submission of gasoline deposit control 

additive samples under the alternative gasoline detergent 

certification option.

80.161(b)(3)(ii)(C) Amended to reflect that documentation of the fuel injector 

deposit demonstration test will be required under the alternative 

gasoline deposit control certification option.

80.161(b)(3)(v) Amended to state that the results of the intake valve and fuel 

injector deposit demonstration test must be submitted to EPA as 

part of the certification letter under the alternative gasoline 

deposit control certification option.

80.161(b)(3)(viii) Amended to change “PFID test” to “fuel injector test”.

80.161(d)(1) Amended to reflect the availability of the alternative gasoline 

deposit control certification option.

80.163(a)(1)(iii) Amended to specify that gasoline deposit control additives may

be certified under the new alternative certification option.

80.164(a) Amended to reference the test fuel requirements under the 

alternative gasoline deposit control certification option.

80.165 Amended to accommodate the alternative deposit control test 

procedures and standards under the alternative gasoline deposit 

control certification option.

80.167(a) Amended to specify how confirmatory testing will be 

conducted for additives certified under the alternative gasoline 

deposit control certification option.

80.176 Added to specify the certification test procedures and standards 

under the alternative gasoline deposit control certification 

option.

80.177 Added to specify the certification test fuels under the alternative 

gasoline deposit control certification option.

80.178 Added to incorporate standards and test methods by reference.

80.330 Revised sampling and testing requirements.

80.340 Amended to add standards for gasoline produced by blending 

pentane into previously certified gasoline.

80.370 Amended to require identification of test method used and 

revises reporting requirements.

80.511 Revised per-gallon and marker requirements.

80.572 Revised labeling requirements. Amended to remove the 

requirement for 15 ppm highway diesel fuel pump labels 

beginning November 30, 2014, and to amend the title to reflect 

that the section includes labeling requirements for dispensers of 
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motor vehicle diesel fuel.

80.573 Revised labeling requirements.

80.574 Revised labeling requirements.

80.580 Incorporated test methods by reference.

80.584(b)(3)(i) Amended to correct typographical error (“notc” to “not”).

80.585 Revised test method approval process.

80.604 Revised reporting requirements.

80.1235(a)(6) Amended to allow refiners and importers who are blending 

blendstock into previously certified gasoline (PCG) an 

alternative to directly test the blendstock for benzene.

80.1235(a)(5) Amended to clarify that refiners and importers may use either 

approach for blendstocks that are blended into either 

conventional gasoline or reformulated gasoline.

80.1235(b)(2) Amended to clarify EPA’s intent (per §80.1238(b)) to allow 

refiners and importers to include oxygenate blended 

downstream of a refinery or import facility in their annual 

average benzene calculation, and to make the section consistent 

with §80.1238(b).

80.1238 Revised benzene determination.

80.1347(a)(5) Amended to require that a negative annual average must be 

reported as zero, and that a refiner must comply with §80.65(i) 

when producing RBOB or RFG and §80.101(g)(9) when 

producing conventional gasoline.

80.1347(a)(6) Added to allow refiners and importers who are blending 

blendstock into previously certified gasoline (PCG) an 

alternative to directly test the blendstock for benzene.

80.1348 Revised sample retention requirements.

80.1349 Added to allow importers who import gasoline into the U.S. by

truck to use the sampling and testing requirements in 40 CFR 

part 80 subpart E as an alternative to the sampling and testing 

requirements in subpart L.

80.1354 Revised reporting requirements for gasoline benzene program.

80.1407 Amended to reflect that pentane blenders incur a renewable 

volume obligation (RVO) for the blender grade pentane they

add to previously certified gasoline (PCG)

80.1451 Revised RFS reporting requirements.

80.1640(d) Added to allow refiners who blend only blender-grade pentane 

into PCG to meet the sampling and testing requirements for

sulfur by using sulfur test results pursuant to §80.85.
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1. Fuels Program Regulatory Streamlining

a. Amendments Related to Reduction of Testing and Reporting of

Complex Model Gasoline Parameters

In §§80.65 and 80.75, we are streamlining and reducing the reformulated gasoline 

(RFG) and conventional gasoline (CG) testing and reporting burden of gasoline refiners 

and importers by reducing the testing and reporting requirements of certain fuel 

parameters associated with the complex model. Currently, for RFG, every batch must be 

tested for every parameter listed in §80.65. No monthly compositing of batch samples is 

allowed for any parameter. For CG, monthly compositing and batch reporting based on 

those monthly composites is allowed for all parameters except sulfur and benzene. With 

the phasing out of complex model standards487, reduced testing and reporting is 

appropriate, particularly for RFG. In cases where a refiner is subject to only benzene, 

RVP, and sulfur standards, certain parameters no longer need to be tested and reported on 

an every-batch basis. However, the full slate of complex model parameters will still be 

needed in some cases. Specifically, refiners producing RFG during the summer volatile 

organic compound (VOC) control season will still need to use the complex model to 

determine VOC performance, and thus must still measure and report the relevant 

complex model fuel parameters. In addition, small refiners that are subject to the delayed 

compliance option for the 0.62 volume percent benzene standard will have to use the 

complex model (and thus measure all complex model parameters) until 2015 for CG 

MSAT1 compliance.488

Currently, there are 17 complex model parameters on the RFG/anti-dumping 

batch report. We are reducing testing and reporting requirements for some of these 

parameters for RFG, CG or both. For both RFG and CG, we are eliminating testing and 

reporting of American Petroleum Institute (API) gravity. In addition, we are finalizing 

that oxygenates need not be reported unless the refiner’s gasoline includes oxygenates or 

the refiner is including downstream added oxygenate in its compliance calculations. 

Apart from being necessary for use in the complex model, these parameters have little 

use for program compliance. Commenters agreed with the elimination of testing of API 

gravity and oxygenates. 

For winter RFG, we are eliminating the requirement to test and report aromatics, 

distillations and olefins on an every batch basis and instead will allow testing and 

reporting of monthly composites. Commenters from the refining industry strongly 

suggested that we eliminate testing of these parameters altogether, since they are not 

needed, and their elimination would further reduce the burden on regulated parties. 

While we agree that a reduction in burden would occur if refiners were not required to 

 

487 Per §§80.41(e) and (f), and §80.101(c), applicable NOx and toxics emissions requirements are 

superseded by the Tier 2 gasoline sulfur standards and MSAT2 benzene standards, respectively.

488 61 FR 17230 (March 29, 2001).
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test, even on a monthly composite basis, for these parameters, the many interconnected 

aspects of the RFG program make any seemingly innocuous change potentially fraught 

with unintended consequences. Thus, we are deferring the consideration of any action to 

completely eliminate the testing of these parameters to any future fuel program 

restructuring, as discussed in Section VI.A.5.

Sulfur and benzene will continue to be tested and reported on an every batch basis 

as these values are necessary for the Tier 2 and Tier 3 gasoline sulfur and MSAT2 

benzene programs. All summer complex model parameters will still be required to be 

tested and reported on an every batch basis because of the summer VOC requirement for 

RFG. For CG, only benzene, sulfur, and any oxygenates that are actually included in the 

gasoline batch must be tested and reported on an every-batch basis (except for refiners 

that are still subject to a complex model toxics standard; they must test all parameters but 

may use monthly composite testing and reporting except for sulfur and benzene, and 

oxygenate, where applicable). In the proposal, we stated “...values for aromatics, 

olefins, and distillation terms may continue to be determined from monthly composites.” 

Some commenters thought the term “may” in that sentence meant that reporting on those 

parameters at all is optional. That is an incorrect interpretation. In this final rule, we are 

finalizing requirements for use of either monthly composites or batch testing. The 

parameters must still be measured and reported. Commenters in the refining industry do 

not think these parameters need to be measured at all for parties subject to the MSAT2 

benzene standard, as compliance with that standard is not dependent on aromatic, olefin, 

or distillation values. As mentioned earlier, there are several areas of the RFG and/or 

anti-dumping programs where testing and reporting burden could likely be reduced; 

however, we have not fully evaluated the implications of changing the current 

requirements, and thus we are leaving consideration of such changes to the broader 

program restructuring discussed in Section VI.A5. Nonetheless, the changes that are 

finalized today will substantially reduce the testing and reporting burden on regulated 

parties.

b. Amendments Related to Reporting Dates

EPA is amending various provisions in 40 CFR parts 79 and 80 to reduce the 

number of different reporting deadlines that regulated parties must meet and to enable the 

future use of a unified and simplified reporting form. Currently under 40 CFR parts 79 

and 80, there are ten separate cyclical reporting dates each year (eleven in a leap year). 

Streamlining reporting deadlines will allow EPA to develop a single, user-friendly, 

electronic form that will collect all required data, maximizing the capability of electronic 

reporting to provide reuse of data and avoid duplicate data submission. EPA’s goal is to 

simplify reporting and reduce the number of hours parties spend preparing and submitting 

reports while simultaneously improving data received from stakeholders. This overall 

effort responds to Executive Orders 13563 and 13610, which direct government agencies 

to simplify rules and to achieve reductions in paperwork and reporting burdens, and is 

part of EPA’s agency-wide effort to streamline regulatory reporting requirements.
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We are amending these deadlines so that all affected programs use the same four 

reporting deadlines. Programs that will be affected by this change include: 

 the fuels and fuel additives registration program (40 CFR part 79, subpart A);

 the Reformulated Gasoline and Anti-Dumping program (40 CFR part 80, subparts 

D and E);

 the Gasoline Sulfur program (40 CFR part 80 subpart H);

 the Motor Vehicle, Nonroad, Locomotive, and Marine Diesel program (40 CFR 

part 80 subpart I);

 the Gasoline Benzene program (40 CFR part 80 subpart L);

 the Renewable Fuel Standard program (40 CFR part 80 subparts K and M); and

 the Tier 3 program being finalized today (40 CFR part 80 subpart O). 

We are finalizing that reporting deadlines will be standardized as follows: June 1, 

for all reports covering quarter 1 of the compliance year (January through March); 

September 1, for quarter 2 (April through June); December 1, for quarter 3 (July through 

September); and March 31 for quarter 4 (October through December). End-of-year 

compliance reports will also be due on March 31. These changes will either delay or 

maintain current deadlines for nearly all required reports. Deadlines for all other annual 

reports will either be maintained if they matched the new quarterly deadline, or extended 

to match the new quarterly deadline. It should be noted that even with the changes 

finalized today, respondents will still have the option to report earlier than any given 

deadline. Commenters generally agreed with the proposed date changes. Some 

commenters in the refining industry suggested eliminating all quarterly reporting for RFG 

if winter aromatics, olefins and distillation are no longer required to be reported as they

suggested. These values are normally reported in the 1st and 4th quarters. As one 

commenter stated, “In addition, there is no point in splitting up summer RFG/RBOB 

reporting between the 2nd and 3rd quarters.” As noted above, winter aromatics, olefins 

and distillation are still required to be reported, albeit on a monthly composite basis. 

Thus, the need for quarterly reporting remains. However, we expect that the need for 

quarterly reports will be evaluated as part of the broader program restructuring discussed 

in Section VI.A.5.

EPA proposed not to include “Attest Engagements” (currently due May 31 of the 

following year) or reporting related to specific events under the Fuels Program, such as 

trading Renewable Identification Numbers (RINs) in EPA’s Moderated Transaction 

System (EMTS), in the reporting revisions described above. Rather, all reporting 

deadlines for Attest Engagements and reporting specific events will remain the same. 

Some commenters communicated that if the annual and fourth quarter reporting deadlines 
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were to be extended to March 31 of each year, then the attest engagement date should 

also be shifted one month from May 31 to June 30 to allow sufficient time for the 

significant data-gathering and communications required to complete those engagements. 

EPA is not changing the compliance period associated with the new extended reporting 

date, but rather, is simply allowing additional time for data review, preparation and 

reporting. EPA does not believe that extending the attest engagement date is necessary

because companies have the flexibility to use the extra reporting time to begin 

preparation for the attest engagement if they prefer. As stated previously, the extension to 

reporting deadlines does not preclude stakeholders from reporting before the deadline. 

EPA is not extending the date for attest engagements from May 31 to June 30. That said, 

EPA is streamlining reporting dates to aid in our development of a single electronic 

reporting format and is updating the due date for attest engagements found in part 80 

from May 31 to June 1. This change will not affect compliance or increase burden of 

reporting entities. Rather, the purpose of streamlining various reporting deadlines is to 

ease reporting burden and help aid EPA in the development and implementation of a 

single electronic reporting format.

We are also correcting a typographical error in 40 CFR 80.1451(f)(2) and 

clarifying that reports are to be signed by the “responsible corporate officer.” One 

commenter suggested that EPA revise the instances when a “responsible corporate 

officer” signature is required, and when perhaps someone else in the company can sign. 

The example given in the comment was that a phone number change should not require a 

“responsible corporate officer” signature, as getting this level of signature can be 

burdensome, and the company can have appropriate delegations in place when someone 

other than the “responsible corporate officer” is the signatory. While we understand the 

concern expressed, EPA does not believe a regulatory action is necessary to address this 

concern but rather believes this issue is best addressed via administrative procedures. 

EPA plans to further evaluate this specific concern and similar “responsible corporate 

officer” issues and address the concerns in the future, outside of the regulatory

framework.

Finally, we are addressing a typographical error in the regulatory text. 

Specifically, incorrect references under 40 CFR 79.5(a)(2) and 79.5(b) are being 

addressed as well as clarification being added.

c. Amendments to Update Fuel Parameter Test Methods

Refiners, importers and oxygenate blenders producing gasoline and diesel motor 

vehicle fuel are required to test RFG, CG and diesel fuel for various fuel parameters 

including aromatics, benzene, distillation, olefins, oxygenate content, RVP, and sulfur. 

As stated in the proposal, a number of relevant regulatory provisions had references to 

test methods that have been revised and updated. Several comments were received 

indicating that since the time of the proposal, some of the proposed updates have been 

further revised and updated and the desire was expressed for the regulated community to 

have the opportunity to use the most current version of each of these test methods. 
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Today, we are updating those test methods to reflect current test methods in order to 

ensure that all test methods are readily available to the regulated community. ASTM 

International (ASTM) test method D2622 is currently the designated test method for 

measuring sulfur, in gasoline and diesel fuel at the 500 ppm sulfur standard. 

(§§80.46(a)(1), 80.580(b)(2).) ASTM test methods D5453, D6920, D3120 and D7039 

are currently alternative test methods for measuring sulfur in gasoline. (§§80.46(a)(3)(i), 

80.46(a)(3)(ii), 80.46(a)(3)(iii), 80.46(a)(3)(iv).) ASTM test method D5453 is also an 

alternative test method for measuring sulfur in diesel fuel at the 500 ppm sulfur standard, 

as well as ASTM test method D4294. (§80.580(c)(2).) ASTM test method D6667 is 

currently the designated test method for measuring sulfur in butane. (§80.46 (a)(2).) 

ASTM test methods D4468 and D3246 are currently alternative test methods for 

measuring the sulfur content in butane. (§§80.46(a)(4)(i), 80.46(a)(4)(ii).) ASTM D1319 

is currently the designated test method for measuring olefins in gasoline and aromatics in 

diesel fuel and is also allowed as an alternative test method for measuring aromatics in 

gasoline. (§§80.46(b), 80.2(z), and 80.46(f)(3), respectively.) ASTM D6550 is currently 

an alternative test method for measuring olefins in gasoline. (§80.46(b)(2)(i).) ASTM 

test method D5599 is currently the designated test method for measuring oxygenates in 

gasoline. (§80.46(g)(1).) ASTM test method D4815 is currently an alternative test 

method for measuring oxygenates in gasoline. (§80.46(g)(2).) ASTM test method 

D5769 is currently the designated test method for measuring aromatics in gasoline. 

(§80.46(f)(1).) ASTM test method D3606 is currently the designated test method for 

measuring benzene in gasoline. (§80.46(e).) ASTM test method D86 is currently the 

designated test method for measuring the distillation of gasoline. (§80.46(d).) ASTM 

test method D5191 is currently the designated test method for measuring the RVP of 

gasoline. (§80.46(c).) ASTM test method D976 is currently the designated test method 

for measuring the Cetane Index of diesel fuel. (§80.2(w).) ASTM standard practice 

D4057 is currently the manual sampling standard practice for petroleum and petroleum 

products. (§80.8(a).) ASTM standard practice D4177 is currently the automatic 

sampling standard practice for petroleum and petroleum products. (§80.8(b).) ASTM 

standard practice D5842 is currently the RVP sampling standard practice for fuels. 

(§80.8(c).) ASTM standard practice D5854 is currently the composite sampling standard 

practice for petroleum and petroleum products. (§80.8(a).)

Table VI-2 lists the designated analytical test methods and alternative analytical 

test methods for RFG, CG and diesel fuel that we are updating in today’s action. The 

Agency has reviewed these updated ASTM test methods and believes that the revisions 

contained in them will result in improvements in the utilization of these test methods for 

the regulated industry. We also believe that our revisions to these test methods will not 

result in significant changes that would cause a user of an older version of the same 

method to incur increased compliance costs. Moreover, all of the revisions were deemed 

necessary by ASTM so that improvements in the test method’s procedures would ensure 

better operation for the user of the test method. Thus, EPA is today updating the 

regulations for the following ASTM test methods: 1) ASTM D2622-10, the designated 

test method for measuring sulfur in RFG, CG, and alternative test method for diesel fuel 

at the 500 ppm sulfur standard; 2) ASTM D3120-08, alternative test method for sulfur in 
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gasoline; 3) ASTM D4294-10, alternative test method for sulfur in diesel fuel at the 500 

ppm sulfur standard; 4) ASTM D5453-12, alternative test method for sulfur in gasoline 

and diesel fuel at the 500 ppm sulfur standard; 5) ASTM D6667-10, designated test 

method for sulfur in butane; 6) ASTM D4468-85(Reapproved 2011), alternative test 

method for sulfur in butane; 7) ASTM D3246-11, alternative test method for sulfur in 

butane; 8) ASTM D1319-13, designated test method for measuring olefins in gasoline 

and aromatics in diesel fuel, as well as the alternative test method for measuring 

aromatics in gasoline; 9) ASTM D6550-10, alternative test method for measuring olefin 

content in gasoline; 10) ASTM D4815-13, alternative test method for measuring 

oxygenate content in gasoline; 11) ASTM D5599-00 (2010), the designated test method 

for measuring oxygen content in gasoline; 12) ASTM D5769-10, the designated test 

method for measuring aromatics in gasoline; 13) ASTM D3606-10, the designated test 

method for measuring benzene in gasoline; 14) ASTM D86-12, the designated test 

method for measuring distillation properties of gasoline; 15) ASTM D5191-12, the 

designated test method for measuring the RVP of gasoline; 16) ASTM D976-06(2011), 

the designated test method for measuring the Cetane Index of diesel fuel; and 17) ASTM 

D7039-13, alternative test method for measuring sulfur in gasoline.

Table VI-2 Designated & Alternative ASTM International Analytical Test Methods 

Under RFG, CG & Diesel Motor Vehicle Fuel Programs

Fuel Parameter ASTM Analytical Test Method

Sulfur (designated test 

method for gasoline)

ASTM D2622-10, entitled “Standard Test Method for 

Sulfur in Petroleum Products by Wavelength Dispersive 

X-Ray Fluorescence Spectrometry”

Sulfur (designated test 

method for 500 ppm 

sulfur diesel)

ASTM D2622-10, entitled “Standard Test Method for 

Sulfur in Petroleum Products by Wavelength Dispersive 

X-Ray Fluorescence Spectrometry”

Sulfur (alternative test 

method for gasoline)

ASTM D3120-08, entitled, “Standard Test Method for 

Trace Quantities of Sulfur in Light Petroleum 

Hydrocarbons by Oxidative Microcoulometry”

Sulfur (alternative test 

method for 500 ppm 

sulfur diesel)

ASTM D4294-10, entitled, “Standard Test Method for 

Sulfur in Petroleum Products by Energy Dispersive X-ray

Fluorescence Spectrometry”

Sulfur (alternative test 

method for gasoline)

ASTM D5453-12, entitled, “Standard Test Method for 

Determination of Total Sulfur in Light Hydrocarbons, 

Spark Ignition Engine Fuel, Diesel Engine Fuel, and 

Engine Oil by Ultraviolet Fluorescence”

Sulfur (alternative test 

method for 500 ppm 

sulfur diesel)

ASTM D5453-12, entitled, “Standard Test Method for 

Determination of Total Sulfur in Light Hydrocarbons, 

Spark Ignition Engine Fuel, Diesel Engine Fuel, and 

Engine Oil by Ultraviolet Fluorescence”

Sulfur (designated test 

method for butane)

ASTM D6667-10, entitled, “Standard Test Method for 

Determination of Total Volatile Sulfur in Gaseous 

Hydrocarbons and Liquefied Petroleum Gases by 
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Ultraviolet Fluorescence”

Sulfur (alternative test 

method for butane)

ASTM D4468-85(Reapproved 2011), entitled, “Standard 

Test Method for Total Sulfur in Gaseous Fuels by 

Hydrogenolysis and Rateometric Colorimetry”

Sulfur (alternative test 

method for butane)

ASTM D3246-11, entitled, “Standard Test Method for 

Sulfur in Petroleum Gas by Oxidative Microcoulometry”

Olefins (designated test 

method for gasoline)

ASTM D1319-13, entitled “Standard Test Method for 

Hydrocarbon Types in Liquid Petroleum Products by

Fluorescent Indicator Adsorption”

Aromatics (alternative 

test method for 

gasoline and 

designated test method 

for diesel)

ASTM D1319-13, entitled “Standard Test Method for 

Hydrocarbon Types in Liquid Petroleum Products by

Fluorescent Indicator Absorption,” for diesel fuel, this 

method is the designated test method; for gasoline, this 

method is an alternative test method and if used as an 

alternative method, its results must be correlated to 

ASTM D5769.

Olefins (alternative test 

method for gasoline)

ASTM D6550-10, entitled, “Standard Test Method for the 

Determination of Olefin Content of Gasolines by

Supercritical-Fluid Chromatography”

Oxygen content 

(designated test 

method for gasoline)

ASTM D5599-00 (2010), entitled, “Standard Test Method 

for Determination of Oxygenates in Gasoline by Gas 

Chromatography and Oxygen Selective Flame Ionization 

Detection”

Oxygen content 

(alternative test method 

for gasoline)

ASTM D4815-13, entitled “Standard Test Method for 

Determination of MTBE, ETBE, TAME, DIPE, tertiaryAmyl Alcohol and C1 to C4 Alcohols in Gasoline by Gas 

Chromatography”

Aromatics (designated 

test method for 

gasoline)

ASTM D5769-10, entitled, “Standard Test Method for 

Determination of Benzene, Toluene, and Total Aromatics 

in Finished Gasolines by Gas Chromatography/Mass 

Spectrometry”

Benzene (designated 

test method for 

gasoline)

ASTM D3606-10, entitled, “Standard Test Method for 

Determination of Benzene and Toluene in Finished Motor 

and Aviation Gasoline by Gas Chromatography”

Distillation (designated 

test method for 

gasoline)

ASTM D86-12, entitled, “Standard Test Method for 

Distillation of Petroleum Products at Atmospheric 

Pressure”

Reid Vapor Pressure 

(designated test 

method for gasoline)

ASTM D5191-12, entitled, “Standard Test Method for 

Vapor Pressure of Petroleum Products (Mini-Method)”

Cetane Index 

(designated test 

method for diesel)

ASTM D976-06(2011), entitled, “Standard Test Method 

for Calculated Cetane Index of Distillate Fuels”

Sulfur (alternative test ASTM D7039-13, entitled, “Standard Test Method for 
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method for gasoline) Sulfur in Gasoline, Diesel Fuel, Jet Fuel, Kerosine, 

Biodiesel, Biodiesel Blends, and Gasoline Ethanol Blends 

by Monochromatic Wavelength Dispersive X-ray

Fluorescence Spectrometry” 

d. Amendments Related to Downstream Blending and Upstream 

Refiner/Importer Compliance Determination

Today’s rule also clarifies the list of products that are not to be included in a 

refinery’s or importer’s compliance determination under §80.1240. Refiners and 

importers are currently required under §80.1235(b)(2) to exclude oxygenate added to 

finished gasoline, RBOB or CBOB downstream of either the refinery that produced the 

gasoline or the import facility where the gasoline was imported. This conflicts with 

EPA’s intended approach in §80.1238(b), which allows refiners and importers to include 

oxygenate blended downstream of a refinery or import facility in their annual average 

benzene calculation, provided the refiner or importer meets certain requirements. We are 

finalizing changes that will allow refiners and importers to include oxygenate blended 

downstream of their facility and that will make these related sections consistent. EPA 

received significant support for this action from commenters. 

e. Amendments Regarding Previously Certified Gasoline

For compliance with the MSAT2 regulations, for blendstock that is blended into 

previously certified gasoline (PCG), we are providing flexibility for refiners and 

importers by providing an alternative allowing them to directly sample and test each 

batch of blendstock, and treat the blendstock as a produced batch. We are adding 

§80.1347(a)(6) to reflect this alternative. This practice is already allowed under the Tier 

2 sulfur program (at §80.340(a)(2)). Refiners and importers are currently required to 

determine the benzene content of the PCG before the addition of blendstock, determine 

the benzene content of the combined blend of PCG and blendstock, and calculate the 

properties of the blendstock by treating the PCG as a negative volume batch and treating 

the blended product as a positive batch. Due to variability in the benzene test method, the 

PCG approach can sometimes result in calculated blendstock benzene concentrations that 

are negative, which is physically impossible. We are amending the regulations at 

§80.1235(a)(6) (and adding §80.1347(a)(6), as mentioned) to allow refiners and 

importers who blend blendstock into PCG to directly test the blendstock for benzene. We 

expect that this method will improve accuracy and ensure a positive benzene test result. 

Also, today’s action will clarify that regardless of the approach used, a negative sulfur or 

benzene result cannot be reported; rather, any negative result must be rounded to zero. 

Similarly, no negative annual average result can be reported. We are also amending the 

regulations at §80.1235(a)(5) to clarify that refiners and importers may use either 

approach for blendstocks that are blended into either conventional gasoline or 

reformulated gasoline.
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Lastly, we are allowing importers who import gasoline into the United States by 

truck to use the sampling and testing requirements in subpart E for truck importers as an 

alternative to the sampling and testing requirements in subpart L. EPA provided these 

alternative requirements in subpart E to eliminate the need to test every truckload of 

imported conventional gasoline for all complex model parameters, including benzene.489 

Since Subpart L also requires importers to test every truckload of imported gasoline for 

benzene, EPA believes it is appropriate to allow truck importers of gasoline to use the 

sampling and testing requirements in subpart E as an alternative. We are amending the 

regulations to provide this alternative by adding a new §80.1349. EPA received 

significant support for this action from commenters.

f. Amendments Related to Designation of an Alternative Lab

Refiners have indicated to EPA that significant problems are created when a 

facility’s designated lab is nonoperational and testing cannot be performed at the lab 

during that time period. We are thus finalizing (at §80.65(f)(5)) that a facility will have 

the ability to designate a back-up or alternative lab for testing during such times. In no 

case could this alternative lab be used to select the best test result, rather it may only be 

used on those occasions where operational necessity causes a need for it (e.g., the normal 

lab is closed, the apparatus for certain test methods are down, or independent lab 

personnel are not available). EPA received significant support for this action from 

commenters.

g. Amendments Related to De Minimis Reporting Changes

We proposed that parties who submit batch reports would not be required to 

correct inconsequential errors in reporting batch volumes under certain conditions, the 

primary condition being that the discrepancy met the definition of “de minimis”, which as 

proposed, was an amount no greater than the smaller of 500 gallons or one (1) percent of 

the true batch volume. Under the proposal, regulated parties would no longer be required 

to provide a complete resubmission of a compliance report when a minor discrepancy of 

a few barrels was uncovered. We proposed that this new provision would apply to 

reporting for RFG, anti-dumping, gasoline and diesel sulfur, and MSAT2. We proposed 

that it would also apply to the RFS renewable volume obligation (RVO), but would only 

apply to the volume of fuels produced or exported that result in a RVO for obligated 

parties. 

We received comments on this proposed change, many of which generally agreed 

with our concept. However, commenters who agreed with the concept stated that they 

believe the proposed levels are so small that they are of little practical value, and that a de 

minimis volume of 500 gallons will almost always be less than 1 percent of the true batch 

volume. In examples provided, commenters stated that pipeline batch volumes are 

 

489 70 FR 74561 (December 15, 2005).
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approximately 25,000 barrels, and that a 500 gallon difference equates to a 0.05% 

difference; 500 gallons on a 250,000 gallon refinery production batch equates to 0.005%. 

Thus, according to the commenters, the 500 gallon limit – which is clearly less than 1% 

in the two examples - would fail to provide the intended relief and would not prevent a 

party from having to make inconsequential volume corrections. These commenters 

suggested that a de minimis threshold value of 0.5 percent be applied regardless of batch 

size. Several commenters also recommended that we delete the proposed regulatory text 

at §80.10 (c) and (d), as the application of a de minimis threshold implies that small 

volume errors in batch reporting are truly inconsequential and do not have an impact on 

compliance with fuel standards, so no separate demonstration of material impact should 

be required. 

One commenter stated that it opposes the de minimis provision with respect to the 

RFS program. According to the commenter, EPA did not provide sufficient legal or 

factual basis for the proposal in order for the public to provide meaningful comment. In 

addition, according to the commenter, the proposed de minimis change, if finalized, 

would allow obligated parties to under report their volume, thereby reducing their RVO.

The commenter also stated that EPA cannot finalize the proposed provision based on 

other comments it receives because, according to the commenter, EPA would still not be 

satisfying notice and comment requirements.

We have decided not to finalize the proposed de minimis provisions at this time. 

One of the primary motivations for proposing the de minimis provision was to avoid the 

need for inconsequential corrections to production volumes that would have no impact on

compliance with standards that rely on production volumes (e.g., average standards and 

RFS). Late changes to production volumes for whatever reason can necessitate 

simultaneous changes to compliance calculations that, if de minimis, would have no 

meaningful impact on compliance. However, as comments highlight, it is has proven 

difficult to come up with an acceptable de minimis threshold that can apply across all 

potential situations. Furthermore, the proposed provision focused only on volume 

corrections, but in reality our experience suggests that corrections often take place for 

other purposes such as data entry, coding, formating or other typographical errors – not 

only minor corrections to reported volume. We believe that adjusting reports for 

inconsistencies will become less burdensome, as EPA intends to transition all reporting to 

electronic reporting in the future. In addition, EPA received input from the regulated 

community about a de minimis provision specifically as it related to the RFS program. 

As discussed below in Section VI.A.1.h, we are finalizing a one-month delay in the RFS 

reporting deadline, which we believe will provide obligated parties with more time to 

review and correct their records and reports, and help to minimize the need for late 

corrections. We will revisit the need for a de minimis threshold in the future if these 

changes prove insufficient.
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h. Amendments Related to RFS2 Annual Report Date

EPA is finalizing the proposed changes to the RFS2 annual report date from the 

last day of February to March 31. EPA intended the change would 1) alleviate staffing 

problems for regulated entities because the regulatory requirements are often handled by 

the same personnel and 2) provide relief from the urgent need to obtain RINs when small 

discrepancies in gasoline production or import volumes are realized. Another reason for 

proposing a change to the reporting deadline from the last day in February to March 31 

was described in Section VI.A.1.b. (Amendments Related to Reporting Dates). 

Streamlining reporting dates will allow EPA to develop a single, user-friendly, electronic 

form that will collect all required data, maximizing the capability of electronic reporting 

to provide reuse of data and avoid duplicate data submission. Commenters generally 

agreed with the proposed date change. One commenter pointed out that the staffing issue 

described would not be addressed by the change date because EPA is changing both RFG 

and Anti-dumping compliance deadlines to March 31 – same as the RFS2 annual 

reporting. EPA understands the point made but nonetheless, believes that delaying the 

RFS reporting date will give reporting entities additional time and flexibility to review 

data and will have no impact on emissions, air quality, or compliance with the standard. 

EPA also believes that the overarching goal of streamlining reporting dates to develop a 

single electronic reporting format, in and of itself, will provide general relief to regulated 

parties. Comments received generally support this view. 

EPA requested comment on whether or not the same date extension from the last 

day of February to March 31 should apply to those transferring RINs in EMTS for 

satisfying RVOs under the previous compliance year. Some commenters wanted to have 

RIN trading through the new deadline (March 31), while others wanted trading to end on 

the last day of February to allow time for data cleanup which could improve compliance 

and reporting accuracy. One commenter also pointed out that changing the RIN trading 

deadline might have an unforeseen impact on the RIN market and suggested EPA 

carefully consider this possibility before making a decision on extending the RIN trading 

date. EPA agrees that providing enough time for data cleanup is important to ensure 

reporting accuracy and meet compliance goals. In addition, EPA understands 

stakeholders’ concerns about how such a change in RIN trading could conceivably

impact the RIN trading market dynamics. As such, RIN transfers in EMTS for satisfying 

RVOs under the previous compliance year will continue to end on the last day of 

February. 

i. Amendments to the Highway Diesel Pump Label Requirements 

We are removing the requirement for diesel fuel pump labels for 15 ppm highway

diesel fuel. Beginning December 1, 2010, all highway diesel fuel was required to be 15 

ppm or less; thus, highway diesel fuel labels are no longer needed to distinguish it from 

500 ppm highway diesel fuel. However, we do recognize that it may confuse consumers 

who are accustomed to seeing the highway diesel fuel pump labels if those labels were to 

disappear, thus, retail and wholesale purchaser-consumer facilities will be free to 
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continue labeling to eliminate confusion if they so choose. The elimination of this 

requirement from the regulations does not preclude retail and wholesale purchaserconsumer facilities from keeping 15 ppm highway diesel fuel labels, it only eliminates 

the EPA requirement that such labels must be present. 

Comments from parties in the fuels industry expressed support for this proposal. 

Additionally, we received a comment suggesting that the requirement of vehicle labeling 

for 15 ppm highway diesel fuel (ultra low sulfur diesel fuel, or “ULSD”) should also be 

removed in conjunction with this change, as the vehicle labels would be unnecessary for 

the same reasons noted for the pump labels. We note that this change was in fact made 

for vehicles under 14,000 lbs GVWR in a previous rulemaking for MY 2014 and later 

vehicles (see 40 CFR 86.1807-01(h)). Further, in today’s action, we are discontinuing 

the ULSD labels for MY 2014 and later vehicles above 14,000 lbs GVWR at 40 CFR 

86.007-35(c).

2. Performance-Based Measurement Systems (PBMS)

Today we are finalizing a performance-based measurement system (PBMS) for 

chemical and physical properties of fuels regulated by EPA’s motor vehicle and engine 

fuel programs. Specifically, they are gasoline properties at §80.46, gasoline sulfur at 

§80.195, and diesel fuel properties at §80.2(z). At proposal, we explained that PBMS 

would set forth procedures and criteria for those laboratories making measurements to 

demonstrate compliance with fuels regulations to qualify alternative analytical test 

methods. We also explained that it would set minimum statistical quality control (SQC) 

requirements, based on standard industry practices, and that laboratories must maintain 

and document the precision and accuracy of analytical methods used in the context of this 

program. We further explained that EPA envisioned that PBMS would provide 

additional flexibility to the regulated industry in choosing test methods and foster 

innovation and improvement in the precision and accuracy of the measurement of motor 

vehicle and engine fuel properties while not reducing the emission benefits that result 

from these fuel programs. We reasoned that PBMS should also provide cost savings to 

the regulated industry by providing rapid access to newly-developed test methods with 

superior speed and ease of analysis. This is because some of these newer methods use 

less-expensive easier to automate instrumentation and smaller quantities of consumables, 

thus, reducing both operating costs and environmental impact (78 FR 29953). Table VI-3

below lists fuel parameters and their corresponding designated test methods that we 

proposed to update. 

Table VI-3 Designated Analytical Test Methods for Gasoline and Diesel Fuel

Fuel Parameter Designated Analytical Method

Sulfur in gasoline ASTM D 2622-10

Sulfur in butane ASTM D 6667-10

500 ppm Sulfur Diesel Fuel ASTM D 2622-10

Olefins in gasoline ASTM 1319-10
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Reid vapor pressure (RVP) in gasoline ASTM D 5191-10b, with the following 

correlation equation:

RVP psi = (0.956 * X) - 0.347

RVP kPa = (0.956 * X) - 2.39

where:

X = total measured vapor pressure in psi or 

kPa.

Distillation in gasoline ASTM D86-11a

Benzene in gasoline ASTM D 3606-10, except that instrument 

parameters shall be adjusted to ensure 

complete resolution of benzene, ethanol, and 

methanol peaks.

Aromatics in gasoline ASTM D 5769-10, except that sample chilling 

requirements in section 8 of this standard are 

optional.

Oxygen and oxygenate content in 

gasoline

ASTM D 5599-00 (2010)

Aromatics in diesel fuel ASTM D1319-10

a. Overview of Proposed Program Requirements

As explained at proposal, in a June 29, 2004 rulemaking, EPA specified a 

performance-based approach for measuring diesel sulfur at 15 ppm and 500 ppm and 

removed previous requirements that had specified particular designated and alternative 

methods for 15ppm diesel sulfur.490 We decided, in that rulemaking, to offer two options 

for test methods for diesel sulfur at the 500 ppm level. The first option required use of 

either the designated test method or specific alternative test methods.491 The second 

option was for a test method to meet performance based requirements similar to those 

adopted for 15 ppm diesel sulfur.492 We proposed extending the performance-based 

approach to method selection and qualification to other parameters besides diesel sulfur, 

with modifications appropriate to accommodate the differences among fuel parameters. 

Today, consistent with our proposal, we are finalizing requirements for PBMS subject to 

a few revisions of certain requirements that we are making in response to comments on 

our proposal.

 

490 See 40 CFR 80.584 and 80.545.

491 See 40 CFR 80.580(c)(2).

492 See 40 CFR 80.584(a)(2), 40 CFR 80.584(b)(2)(i) through 40 CFR 80.584(b)(2)(iii), and 40 CFR 

80.585.
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Specifically, in today’s action we are setting forth requirements that laboratories 

should use to demonstrate the precision493 and accuracy494 of chosen fuel parameter 

measurement methods. As also explained at proposal, PBMS as finalized would: 1) 

require individual laboratories to demonstrate adequate measurement quality, 2) allow 

laboratories to choose methods that meet their own needs, provided they can meet quality

criteria, 3) prescribe criteria rather than specific methods495, and 4) require all 

laboratories making regulatory measurements to establish and maintain a statistical 

quality control program (72 FR 29955). EPA continues to believe that PBMS will not 

compromise on either precision or accuracy relative to the system that exists under 

current regulations. We have also incorporated the standards and practices of Voluntary

Consensus Standard Based (VCSB) organizations wherever feasible.

Today’s requirements apply to the qualification of analytical test instrumentation 

and methods used to measure various characteristics of individual fuel samples. 

Consistent with our proposal, it does not apply to sampling methods or in-line blending 

methods. The Agency received several comments asking to extend PBMS to in-line 

blending methodologies expeditiously. As earlier explained, today’s final action does not 

extend to sampling methods or in-line blending methods. This is because, in-line 

blending already has a certification process that sets forth qualification criteria that take 

into account the unique combinations of sampling, control, and analysis that are involved 

with in-line blending. See 40 CFR 80.65(f).

b. How Can We Establish the Accuracy of the Measurement System (All 

Qualified Methods/Installations) For Each Parameter?

We proposed grouping the gasoline and diesel fuel parameters that must be 

measured (e.g., aromatics, sulfur, etc.), into two categories, depending upon whether it is 

practically feasible to construct and use gravimetric standards496 for defining the 

parameter and thus, for determining the accuracy of a measurement method. To establish 

the accuracy of methods measuring each parameter for which gravimetric standards are 

 

493 Precision – the amount of consistency in a set of measurements performed on the same material. ASTM 

repeatability and reproducibility are examples of measures of precision. ASTM Repeatability (“r”) – the 

difference between successive test results obtained by the same operator with the same apparatus under 

constant operating conditions on identical test material. ASTM Reproducibility (“R”) – the difference 

between two single and independent test results obtained by different operators working in different 

laboratories on identical test material using the same method.

494 Accuracy – the closeness of a single measurement to its true value of what is being measured.

495

 For some parameters the criteria will be based on the laboratory’s chosen method’s ability to closely 

predict the measurements made by EPA’s chosen or “designated” method. This approach is made 

necessary by the “method-dependent” definition of some of the parameters to be measured.

496 Gravimetric standards are test materials made by adding a carefully weighed (hence “gravimetric”) 

quantity of the analyte of interest to a measured quantity of another substance known not to contain any of 

the analyte. The result is a solution with a very accurately known concentration of the analyte. The 

accuracy of gravimetric standard reference materials can be closely controlled and is not dependent on an 

analytical test method. 
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not feasible, we proposed retaining an EPA-prescribed reference method or designated 

method that would, in effect, define the parameter—as in “parameter X is, for federal 

regulatory purposes, whatever method Z measures.” We explained that parameters that 

require such treatment would be described as “method-defined” parameters. We also 

explained that anchoring the accuracy of a method intended to measure such a parameter 

would be accomplished by relating its measurements on a particular set of test fuels to 

measurements made on the same fuels by a laboratory operating the designated method. 

We further explained that this approach is often referred to as “correlating” the new 

method with the designated method. Such a correlative approach to qualification is 

dependent for its workability upon the test fuels used to establish the correlation. They

must be sufficiently varied along all important dimensions so that day-to-day production 

laboratory operations are very unlikely to turn up some unusual fuels (or a new class of 

fuels produced, say, by some new refining process) for which the correlation equation 

derived earlier does not hold true and where the predictions of the designated method’s 

results are quite erratic and inaccurate.

As also explained at proposal, our classification of parameters into the absolute or 

method-defined categories is not entirely straightforward. Of the parameters subject to 

our proposal, only those with sulfur as the analyte seem to fall unambiguously into the 

absolute category. We additionally explained that sulfur is a single element rather than a 

compound (or, worse, a class of compounds with numerous members) and thus lends 

itself to the construction of gravimetric standards. We further explained that the methods 

that are currently used to measure sulfur in gasoline and diesel fuel have been subject to 

intensive recent development work and are largely free of matrix effects. Sulfur in 

butane is, arguably, even more amenable to the absolute approach, since the matrix, 

butane, is a single compound rather than a constantly varying mixture of many

compounds. We noted that the diesel sulfur rule used the absolute approach. We 

therefore proposed to treat gasoline sulfur and sulfur in butane as absolute parameters. 

For a complete discussion of our classification scheme see 78 FR 29955-29956.

Given logical and practical difficulties with using a gravimetric approach to 

qualifying methods for parameters other than sulfur, EPA proposed and sought comment 

on classification of parameters into either the absolute category to be used for sulfur or 

method defined or correlative category to be used for all parameters other than sulfur. 

All comments received were in support of this approach. Therefore, today, EPA is 

adopting a classification of fuel parameters where the absolute category will be used for 

sulfur in gasoline and butane, and a method defined category will be used for all other 

gasoline and diesel fuel parameters.

c. How Would Analytic Methods be Evaluated for Qualification? 

i. General Provisions: To Which Methods and Which Parties do the 

Proposed Requirements Apply?
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We proposed and requested comments on requiring laboratories to qualify all 

methods used in measurements for regulatory purposes. We explained that EPA did not 

believe that a relatively simple qualification test would ensure continued measurement 

quality, but rather that these requirements would greatly reduce the likelihood of a 

laboratory undertaking important measurements without some assurance that an 

instrument is in working order, that at least one operator497 in the laboratory understands 

the method for its use, and that it can be made to perform to meet acceptable criteria. We 

received comments that were supportive of these requirements.

ii. How Would Laboratories Demonstrate the Precision and Accuracy 

of Methods for Measuring “Absolute” Parameters and Thus Qualify 

the Methods for Use?

As explained at proposal, test methods typically used for gasoline sulfur are also 

frequently used for diesel sulfur. We also noted that the ASTM test method designations 

for both are the same. At proposal, we explained that examination of test method 

descriptions, however, pointed toward substantial differences in how these test methods 

are used in the different matrices. Thus, while we considered the possibility of allowing 

the diesel sulfur qualifications to be used also for gasoline sulfur, we believed differences 

between a diesel fuel matrix and gasoline fuel matrix were likely too great to permit such 

a sweeping exemption from qualification requirements. We reasoned that reworking test 

methods to measure gasoline sulfur would, in many cases, generate most of the data 

needed for qualification, and thus would not represent a major additional effort. So, 

despite VCSB-sponsored gasoline sulfur test methods bearing the same organizational 

designations as their diesel counterparts, we proposed to require that these test methods 

qualify separately for use in measuring gasoline sulfur (78 FR 29956). No negative 

comments were received on our proposal to require test methods that have already been 

qualified for diesel fuel to qualify separately for gasoline. Thus, consistent with our 

proposal, we are finalizing requirements for test facilities that have already qualified a 

method for measuring sulfur in diesel fuel to qualify test methods for measuring sulfur in 

gasoline.

Operational Description: We proposed requiring applications for qualification to 

include a complete operational description of the test method in question. For methods 

published by organizations such as ASTM International, we explained that the test 

method designation number and title would satisfy this requirement. We also proposed 

requiring the description to include the scope of the test method, a summary, discussion 

 

497 The intent behind the qualification process is to demonstrate the facility’s capability with the method. 

Accordingly we did not propose that each instrument used to implement a particular method be required to 

qualify (some labs may have several instruments implementing a single method) or that each operator be so 

required. We recommend, but did not propose to require, that a laboratory rotate operators during the 

testing required for qualification, thereby both improving and testing the skills of all operators for a given 

method and strengthening its quality program.
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of interferences that are expected, apparatus needed, reagents, sampling and specimen 

preparation, calibration, test method procedure, calculations, and any test method-specific 

quality control (78 FR 29956). We received comments in support of these requirements 

as well as comments indicating that the regulations should explicitly state that the test 

method designation number and title of the test method would meet the operational 

description requirement for VCSB test methods. The Agency agrees with this comment 

and has modified the final regulations as suggested. In today’s action we are also 

finalizing all other operational description requirements as proposed. 

Precision Qualification: We proposed and sought comments on requirements for 

precision qualification that were similar to requirements set forth in the non-road diesel 

sulfur rule. As explained at proposal that rule imposed a maximum value for the standard 

deviation498 of a series of at least 20 measurements over at least 20 days on a single fuel 

under site precision conditions. Specifically, the diesel rule used 1.5 times the 

repeatability standard deviation (ASTM “r”/2.77) of what was the least precise of the 

then-allowed methods. We explained that the factor of 1.5, expands the allowable 

variability from that of back-to-back tests (as in ASTM’s definition of repeatability) to 

account for the sources of greater variability that find their way into a longer series of 

tests on the same material. We explained that in the qualification process for ultra-low 

sulfur diesel testing, the factor of 1.5 proved to be neither so tight that most laboratories 

were unable to meet it, nor so loose as to not be challenging at all. Thus, we considered it 

to be reasonable, as well as having proven to be workable in practice, and therefore 

proposed that the precision qualification for diesel fuel be applied to both absolute and 

method defined fuel parameters.

Comments were supportive of our proposed precision criteria for the absolute 

fuel parameters of sulfur in gasoline and sulfur in butane. We also received comments 

that were against the extrapolation of precision qualification for absolute fuel parameters 

based on published method repeatability (r) to method defined parameters. These 

comments will be addressed in more detail below under the discussion of precision 

criterion for method defined fuel parameters.

Gasoline Sulfur Precision Criteria: We proposed and sought comments on the 

use of the repeatability for ASTM D7039-07 (i.e., 1.76 ppm at 10 ppm) to set the 

precision criterion for sulfur in gasoline. We reasoned that the maximum allowable 

standard deviation of the twenty test results on a 10 ppm gasoline would be 0.95 ppm499. 

 

498 Where the standard deviation is estimated from a sample of the population (formula uses “N-1” in the 

denominator).

499 This number was determined by using the repeatability equation for “r” from ASTM D7039-07 for a 10 

ppm sulfur gasoline to get 1.76 ppm, dividing the “r” in ppm by 2.77 to obtain the underlying standard 

deviation of 1.39 ppm, and multiplying the result by 1.5 (criterion used in diesel sulfur rule) to get 0.95 

ppm.
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We did not propose to prescribe the parameter level for the fuel used for these precision 

tests, because we believed that this maximum limit will vary depending upon the 

repeatability number that the ASTM D7039-07 test method’s repeatability formula 

yields, given the parameter value of the test fuel chosen. We also explained that if a 

laboratory selected a 5 ppm fuel to test instead of a 10 ppm fuel, the maximum limit for 

the standard deviation would be 0.67 ppm (78 FR 29956-29957). Comments provided 

were in support of this requirement. Thus the Agency is finalizing the precision criterion 

for sulfur in gasoline that is based on the repeatability of ASTM D7039-07. This would 

require dividing it by 2.77 to obtain the underlying standard deviation, and multiplying 

the result by 1.5 to get the applicable precision criterion based on the concentration of 

sulfur in gasoline.

Sulfur in Butane Precision Criteria: We proposed a precision criterion based on 

the repeatability of ASTM D6667-10. We explained that this test method’s repeatability

at the 10 ppm level would be1.15 ppm, and that calculations for sulfur yielded an upper 

limit for the standard deviation of the 20 tests for sulfur in butane of 0.62 ppm (78 FR 

29957). Most of the comments we received were in support of our proposal. We also 

received one comment from the Independent Fuel Terminal Operators Association 

(IFTOA), a trade association for fuel terminal operators, which provided comments on 

behalf of its members. IFTOA expressed concerns over the repeatability calculation we 

provided at proposal for 10 ppm sulfur in butane. IFTOA explained that reduced sulfur 

levels would inhibit butane blending due to reduced availability of butane with very low 

sulfur. IFTOA requested additional flexibility and noted the difficulty and expense 

involved in finding butane with sulfur content of 10 ppm or below. Therefore, IFTOA 

urged the Agency to consider focusing on the sulfur content of the final blend and not the 

sulfur content of the butane component. IFTOA further provided comments urging the 

Agency to allow blenders downstream of the refinery and importer gate to add butane 

that meets the downstream per gallon cap so long as the butane blending operation does 

not cause the blender’s finished gasoline to have annual average sulfur content above 10 

ppm.

The Agency disagrees with IFTOA’s reading of the example calculation provided 

in the proposed preamble and regulations, which utilized the repeatability of ASTM 

D6667-10 as the basis for the precision criterion when the sulfur level of butane was at 10 

ppm. The intent of this example was not to provide a cap on sulfur in butane at 10 ppm, 

but rather only intended to be an example explaining that the precision criterion for sulfur 

in butane would be 0.62 ppm if the sulfur level in butane was 10 ppm. The Agency

agrees with IFTOA that blenders downstream of the refinery and importer gate should be 

permitted to add butane that meets the downstream per gallon cap of 80 ppm so long as 

the butane blending operation does not cause the blender’s finished gasoline to have an 

annual average sulfur content above 10 ppm. Accordingly, today’s final regulations 

include examples if sulfur in butane is at the 80 ppm cap, instead of the 10 ppm sulfur 

average. We are also finalizing precision criteria for sulfur in butane that is based on the 

repeatability of ASTM D6777-10, consistent with our proposal.
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Temporal Distribution of Precision Tests: With regard to spacing of the required 

20 precision tests, we proposed and sought comments on requiring 7 or fewer tests per 

week and 2 or fewer tests per day. We also sought comments on the following two 

options: 1) a requirement that 23 or more hours must elapse between tests (this option 

requires either testing on weekends or an extension of the 20 days); and 2) tests arranged 

into no fewer than five batches of five or fewer tests each, with only one such batch 

allowed per day over 20 days (78 FR 29957). We received comments in support of 

option 2, (i.e., arranging tests into no fewer than five batches or fewer tests each, with 

only one such batch allowed per day over the minimum of 20 days) because, according to 

commenters, it would provide the most flexibility and be easier to implement. Today’s 

rule includes requirements for testing that are consistent with our proposed option 2.

Accuracy Qualification: We proposed and sought comments on accuracy criteria 

for absolute fuel parameters that are similar to the criteria for sulfur in diesel fuel. We 

proposed that applicants for qualification would be required to select two commercially 

available gravimetric standard reference materials (SRM), and then show that their 

laboratory and method are capable of getting an average of ten consecutive results that 

are very close to the Accepted Reference Value (ARV), for each SRM. We proposed to 

use 0.75 times the precision criterion described above, which is the same value for sulfur 

in diesel. We explained that in the case of gasoline sulfur, for a gravimetric standard with 

ARV = 10 ppm, this would be 0.75 times 0.95 ppm or 0.71 ppm. The corresponding 

numbers for sulfur in butane at the 10 ppm level would be 0.75 times 1.15 or 0.47 ppm. 

For other parameters that might eventually fall into the absolute category, we proposed 

that the precision and accuracy criteria would be determined as a function of the ASTM 

repeatability of one of the methods (selected by EPA) available for measuring that 

parameter(78 FR 29957). 500 Comments were supportive of our proposed requirements 

for determining accuracy criteria for absolute fuel parameters. Thus, the Agency is 

finalizing the accuracy qualification criteria as proposed.

iii.How Would Laboratories Demonstrate The Precision and Accuracy 

of Methods for Measuring “Method-Defined” Parameters and Qualify 

the Methods for Use?

Operational Description: We proposed the same operational description 

requirements for both method defined and absolute parameters. We explained that 

 

500 It is important to understand that the numerical examples presented in the text are entirely hypothetical, 

because use of precision testing material or gravimetric standards at levels other than those used in the 

examples would change all of the numbers. Use of a gasoline sulfur gravimetric standard at 5 ppm (instead 

of the 10 ppm used in the example) would require computing the repeatability of the method at 5 ppm using 

the equation given in the method description, dividing it by 2.77, multiplying the result by 1.5, and then 

multiplying that result by 0.75. As a short-cut, the accuracy criterion could be determined by multiplying 

the ASTM repeatability of the method at the level in question by 0.4061.
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publication of a test method by a VCSB organization, such as ASTM, where the test 

method number and title is cited, would meet this criterion. We also explained that a 

non-VCSB test method would require additional information because non-VCSB test 

methods have not been fully vetted by a VCSB. We explained that the underlying 

scientific measurement principles must be thoroughly explained and the apparatus 

described well enough that a trained outsider could successfully implement the nonVCSB test method and replicate the applicant’s results (78 FR 299957). In addition, for 

non-VCSB test method we proposed that the description must include the scope of the 

test method, a summary, discussion of any interferences that are expected, apparatus 

needed, reagents, sampling and specimen preparation, calibration, test method procedure, 

calculations, and any test method-specific quality control. As previously discussed in 

Section VI.A.3.c.ii, we received comments in support of these requirements as well as 

comments indicating that the regulations should explicitly state that the test method 

designation number and title of the test method would meet the operational description 

requirement for VCSB test methods. The Agency agrees with this comment and has 

modified the final regulations as suggested. In today’s action we are also finalizing all 

other operational description requirements as proposed.

Precision Qualification Specifics: We proposed the same precision qualification 

criteria for both method defined and absolute parameters. For reference installations, we 

proposed additional requirements that the instrument must be shown to be in statistical 

control, as provided for in ASTM D6299-10e1 (and the proposed SQC procedures) and 

that the applicant must submit control charts showing a record of in-control operation for 

at least five months. At proposal we acknowledged that while these requirements would 

likely result in a delay between instrument setup and the ability to qualify a reference 

installation, we believed that any delay was necessary to demonstrate the stability of 

these critically important installations. We reasoned that EPA expected no lack of 

laboratories that are capable of meeting these standards considering the number of longestablished installations of these designated test methods (78 FR 29957).

The Agency received several comments from the American Petroleum Institute, 

the Association of Fuel and Fuel Petrochemical Manufacturers, Chevron Products 

Company, and Marathon Petroleum Company LP that were against extrapolating the 

same precision qualification criteria for absolute fuel parameters, which is based on the 

published method’s repeatability (r), to the precision qualification criterion of method 

defined fuel parameters. Specifically, according to the commenters, precision criteria for 

method defined fuel parameters are sensitive to the matrix making up the fuel material 

that is to be analyzed. This degree of sensitivity to the fuel matrix is different for 

different test methods, techniques, and instrumentation that measure the same method 

defined fuel property. Commenters recommended instead that the precision standard 

deviation qualification criterion be based on the Test Performance Index (TPI), as 
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described in ASTM D6792.501 The commenters further explained that the TPI in ASTM 

D6792 sets minimum site precision performance criteria based on test method 

reproducibility (R) and the Precision Ratio (PR) of the published test method. Also, 

commenters noted that using the TPI as outlined ASTM D6792 would be consistent with 

OMB Circular 119, which directs agencies to use voluntary consensus standards in lieu of 

government unique standard except where inconsistent with law or otherwise impractical.

The Agency has evaluated ASTM D6792 and agrees that it would be appropriate 

to base the precision qualification criterion for method defined parameters on the TPI as 

described in ASTM D6792. We also agree that method-defined test methods are subject 

to fuel matrix effects, and therefore, that the degree of sensitivity to the fuel matrix is 

different for different test methods, techniques, and instrumentation that measure the 

same method defined fuel property. Therefore, in a change from proposal, and in 

response to comments, we are requiring that the precision qualification criterion for 

method defined parameters be based on the Test Performance Index (TPI) as described in 

ASTM D6792.

Olefins in Gasoline Criterion: We had proposed to base the precision 

qualification for olefins in gasoline on the repeatability of ASTM D1319-10. Thus, we 

explained that for a test fuel with olefins at, say, 9 volume percent (Vol.%), the 

repeatability would be 0.972, the underlying standard deviation would be 

0.972/2.77=0.351, and the precision criterion would be 1.5 times that or 0.53 Vol.%. We 

had proposed that a laboratory’s standard deviation for the 20 tests could not exceed that 

value and still qualify for precision (78 FR 29957-58). Several commenters including 

the American Petroleum Institute, the Association of Fuel and Fuel Petrochemical

Manufacturers, Chevron Products Company, and Marathon Petroleum Company LP, 

argued that that the precision standard deviation criterion for method-defined parameters 

should be based on the TPI described in ASTM D6792-07.502 Also, both API and AFPM 

stated that using the TPI as outlined in ASTM D6792 is consistent with OMB Circular 

119, which directs agencies to use voluntary consensus standards in lieu of government 

unique standards except where either inconsistent with law or otherwise impractical.

As previously explained, the Agency has evaluated and agrees with the comment 

that the TPI, in ASTM D6792, should be used because it sets minimum site precision 

performance criteria based on test method reproducibility (R) and the Precision Ratio 

(PR) of the published test method. The Agency is therefore, finalizing the requirement 

that precision criteria for olefins in gasoline will be based on the TPI in ASTM D6792. 

Additionally, consistent with our proposal to afford the regulated community the use of 

the most current version of test methods, we are also updating the olefin in gasoline test 

 

501 ASTM D6792-07, entitled, “Standard Practice for Quality System in Petroleum Products and Lubricants 

Testing Laboratories”.

502 ASTM D6792-07, Standard Practice for Quality System in Petroleum Products and Lubricants Testing 

Laboratories1.
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method ASTM D1319 to the 2013 year version, as discussed in Section VI.A.1.a.iii 

above. We are also finalizing requirements that the reproducibility of ASTM D1319-13 

be utilized in setting the precision criterion. For example, the reproducibility is 3.06, and 

the precision criterion is 0.3 times 3.06 or 0.92 volume percent (Vol. %), for a test fuel 

with olefins at 9 Vol. %.

Table VI-4 provides the TPI in ASTM D6792 for setting the olefin precision 

criterion.

Table VI-4 Method-Defined Precision Criterion for Olefins in Gasoline

ASTM 

Method

Property Precision 

Ratio (R/r)

ASTM 

D6792 

minimum

TPI = (r/R’)

Maximum 

acceptable 

site 

precision 

(R’)

Site 

Precision 

Standard 

Deviation 

Qualification 

= R’/2.77

D1319-13 Olefins 3.2 1.2 0.83R 0.3R

Aromatics in Gasoline Criterion: We proposed use of the repeatability standard 

deviation for D1319-10 to set the precision criteria for aromatics in gasoline (78 FR 

29958). As previously explained, in response to comments received on proposed 

requirements for precision criteria for method-defined parameters, such as olefins in 

gasoline, the Agency is finalizing regulations for the use of the TPI in ASTM D6792 

because we believe that it sets minimum site precision performance criteria based on test 

method reproducibility (R) and the Precision Ratio (PR) of the published test method. 

Additionally, as also previously explained, consistent with our proposal to afford the 

regulated community the use of the most current version of test methods, we are updating 

the aromatic in gasoline test method ASTM D1319 to the 2013 year version, as discussed 

in Section VI.A.1.a.iii. Thus, the reproducibility of ASTM D1319-13 should be utilized 

in setting the precision criterion. In today’s action, the Agency is finalizing precision 

criteria for aromatics in gasoline that is based on the TPI in ASTM D6792 TPI. Thus, for 

example, the reproducibility is 3.7, and the precision criterion is 0.3 times 3.7 or 1.11 

Vol. % for a test fuel with aromatics at 32 Vol. %.

Table VI-5 provides the TPI in ASTM D6792 TPI for setting the aromatics 

precision criterion along with the use of ASTM D1319-13’s reproducibility.

Table VI-5 Method-Defined Precision Criterion for Aromatics in Gasoline

ASTM 

Method

Property Precision 

Ratio (R/r)

ASTM 

D6792 

Maximum 

acceptable 

Site 

Precision 
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minimum 

TPI = (r/R’)

site 

precision 

(R’)

Standard 

Deviation 

Qualification 

= R’/2.77

D1319-13 Aromatics 2.8 1.2 0.83R 0.3R

Oxygen and Oxygenates in Gasoline Criterion: We proposed use of the 

repeatability for D5599-00 (2010) to determine the precision criterion for oxygen and 

oxygenates in gasoline. We explained that for a test gasoline with 3 mass% total oxygen, 

the repeatability would be 0.083 mass% and the criterion for precision in this example to 

be 0.045 mass% (78 FR 29958). As previously explained, in response to comments we 

received on our proposed precision criteria for method-defined parameters, the Agency is 

finalizing the use of the TPI in ASTM D6792 for setting precision criteria for method 

defined parameters. Thus, for a test fuel with total oxygenate content at 3 mass % total 

oxygen, the reproducibility would be 0.32, and the precision criterion is 0.3 times 0.32 or 

0.10 mass % total oxygen. Table VI-6 provides the TPI in D6792for setting oxygen and 

oxygenates precision criterion.

Table VI-6 Method-Defined Precision Criterion for Oxygenates in Gasoline

ASTM 

Method Property

Precision 

Ratio (R/r)

ASTM 

D6792 

minimum 

TPI = 

(r/R’)

Maximum 

acceptable 

site 

precision 

(R’)

Site 

Precision 

Standard 

Deviation 

Qualification 

= R’/2.77

D5599—00 

(2010) Oxygenates 6.8 2.4 0.42R 0.15R

For each method defined fuel parameter that lacked alternative test methods we 

proposed a precision criterion of 1.5 times the repeatability for the designated test method 

divided by 2.77. We had proposed that a laboratory’s standard deviation for the 20 tests 

could not exceed that value and still qualify for precision (Table VI-6, 78 FR 29958). As 

explained above, as it relates to the Agency’s response to the proposed precision criterion 

for method defined fuel parameters, the Agency today is finalizing precision criterion as 

provided in Table VI-7 for the various method defined fuel parameters lacking 

alternatives to the designated test method using the ASTM D6792 TPI approach, except 

for distillation. The distillation method defined fuel parameter is discussed in further 

detail below.

Table VI-7 Method-Defined Precision Criterion for Fuel Parameters lacking 

Alternatives to the Designated Test Method

Test Property Precision ASTM Maximum Site 
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Method ratio (R/r) D6792 

minimum 

TPI = 

(R/R’)

acceptable 

site 

precision 

(R’)

Precision 

Standard 

Deviation 

Qualification 

= R’/2.77

D5191-12 RVP 1.9 1.2 0.83R 0.3R

D3606-10 Benzene 4.6 2.4 0.42R 0.15R

D1319-13 Aromatics 

in Diesel 2.8 1.2 0/83R 0.3R

With regard to distillation properties, (which is one of the parameters lacking 

alternatives to designated test methods), several commenters, including API and AFPM, 

recommended the use of ASTM D86-07 for setting the precision criterion for distillation 

properties. According to these commenters, the precision criterion as published in later 

year versions of ASTM D86 is not consistently supportable by actual ASTM ILCC 

program data. As support, they referenced Note 31 of the current ASTM D86 test 

method.503 They commented that a plausible explanation for this is that the 

interlaboratory study (ILS) used to derive the current precision criteria required several 

runs on the ILS material to select heating profile, and hence does not reflect how the 

method is actually conducted in a routine production environment. In addition, the ILS 

study sample set may not adequately cover the range of available real world production 

gasoline. They also stated that there is general consensus that the precision of this test 

method is sensitive to the slope of the boiling curve; hence, a constant precision as 

articulated in the cited ASTM D86-11, a method may not be appropriate as a one-sizefits-all measure for gasolines with different matrices and volatility properties for winter 

as compared to summer fuels. According to commenters, directionally, and based on ongoing discussions with ASTM, it would appear that the ASTM test method precision may

revert to a boiling curve slope based approach, similar to ASTM D86-07. They further 

commented that for gasoline containing ten volume percent ethanol (E10), the boiling 

curve slope and hence precision is impacted by the location of the azeotrope point 

relative to the distillation points of interest (T10, T50 and T90).504 Both API and AFPM 

also commented that the precision function as stated in ASTM D86-07 is a more realistic 

representation for E-10 gasoline precision with different fuel matrices. Finally, API and 

AFPM expressed concerns on the use of ASTM D86-11a precision criteria and the 

proposed precision qualification of 1.5r/2.77, which they described as too restrictive. 

 

503 Note 31 of the current ASTM D86 test method reads “NOTE 31– A new inter laboratory study is being 

planned to address concerns that laboratories are not able to meet the precision for percent evaporated 

temperature at fifty percent.”

504 The azeotrope point is a function of the base stock gasoline composition, and therefore can vary with 

different fuel matrices.
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Both API and AFRPM provided fuel producer control chart data as an example, which is 

reproduced in Table VI-10.505

Table VI-8: API & AFPM Example of ASTM D86-11a Fuel Producer Control Chart 

Data

IBP E10 E50 E90 FBP

Avg F 103.65 151.32 224.88 351.44 417.16

Stdev F 1.93 1.66 1.36 1.22 2.66

Avg C 39.81 66.29 107.16 177.47 213.98

StDev C 1.07 0.92 0.75 0.68 1.48

EPA 

precision 

criteria

1.54 0.72 0.40 0.97 1.80

After reviewing these comments and especially data set out in Table VI-8, we 

agree that our proposed distillation precision criterion would likely be too restrictive, 

especially for the distillation point of E50. Accordingly, in a change from proposal and 

in response to these comments and additional data, the Agency is finalizing precision 

criterion for the gasoline distillation parameter based on 0.3 times the automated 

reproducibility of ASTM D86-07 instead of ASTM D86-11a. Table VI-9 provides the 

precision criterion for the gasoline distillation method defined fuel parameter.

Table VI-9 Method-Defined Precision Criterion for Gasoline Distillation 

based on 0.3 times the Automated Reproducibility of ASTM D86-07

Percent Evaporated Point 0.3* Reproducibility (0C)

Initial Boiling Point 0.3 * 8.5 

10 Percent Evaporated 0.3 *(3.0 +2.64*Sc)

50 Percent Evaporated 0.3*(2.9+3.97*Sc)

90 Percent Evaporated 0.3*(2.0+2.53*Sc)

Final Boiling Point 0.3*10.5

Where Sc is the average slope (or rate 

change) of the gasoline distillation curve as 

calculated in accordance with Section 13.5 

of ASTM D86-07

 

505 The raw data supporting the control data is supplied by API and AFPM in docket EPA-HQ-OAR-2011-

0135.
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Accuracy Qualification: At proposal, we also explained that test methods used to 

measure method-defined parameters would likely fall into three separate tracks: reference 

installations of designated methods intended for use in qualifying alternative methods; 

designated method installations intended for ordinary production measurements; and nondesignated methods. We proposed and sought comments on requirements that reference 

instruments must be shown to have been near the middle of the distribution of the 

industry monthly inter-laboratory crosscheck program (ILCC) for at least five months 

prior to application. We also proposed that laboratories would specifically compute the 

difference between the instrument's average measurement of the fuel closest to the 

applicable standards (or to the average value for the fuel type in the complex model) and 

the robust mean for that fuel obtained by all of the non-outlier labs in the program. We 

further proposed that this difference would be standardized by expressing it in robust 

standard deviation units. These standardized ILCC differences would be put into a 

moving average with a span of, say, 5 months. We proposed to set the standard so that 

the instrument's moving average would be within the central 50% of the distribution of 

participating designated method labs. We also reasoned that because a robust standard 

deviation is used by the ILCC program this percentage will have to be approximate (78 

FR 29958).

Several commenters, including API and AFPM commented on the proposed 

requirements for reference installations of method defined fuel parameters used to qualify

other method defined test methods. These comments and our response to these 

comments are discussed in further detail below.

At proposal we discussed the role of Voluntary Consensus Bodies in qualifying

alternative analytical test methods as well as the use of reference materials in qualifying 

and maintaining such test methods. We requested comments on the appropriateness of 

using three types of standard reference materials for accuracy and on their applicability in 

the qualification process and statistical quality control process of analytical test methods. 

Specifically, we proposed use of the following: 1) Gravimetric standards, 2) Consensus 

named fuels (e.g., gasoline or diesel fuels), and 3) Locally named standards. For a 

complete discussion of these issues see 78 FR 29958-29960. All comments received 

were in support of the use of these kinds of reference materials in the qualification 

process and statistical control program.

d. Qualification Criteria for Designated Method Installations Used to 

Qualify Method-Defined Parameter Instruments.

We proposed the following requirements for designated test method installations 

(also known as are reference installations) that would be used to qualify method-defined 

parameter instruments. We explained that these reference installations would be used to 

evaluate the accuracy of other alternative test methods and to establish correlation 

equations, and as such that we believed that they should be held to higher standards.
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First, we proposed that reference instruments must meet precision qualification 

requirements that are similar to the criteria set forth in the non-road diesel sulfur rule. As 

explained earlier, that rule imposed a maximum value for the standard deviation506 of a 

series of at least 20 measurements over at least 20 days on a single fuel under site 

precision conditions. Specifically, the diesel rule used 1.5 times the repeatability 

standard deviation (ASTM “r”/2.77) of what was the least precise of the then-allowed 

methods. We proposed that for those method-defined parameters, shown in Table VI-6 

of the proposed preamble, lacking currently allowed alternatives to their designated 

methods, the precision criteria would be based on the fuel parameter’s designated test 

method. At proposal, we also explained that in each case the precision criterion is 

determined by (“r”/2.77) times 1.5 where “r” is the ASTM repeatability determined for 

the particular fuel that is being used for the purpose of demonstrating the test method’s 

precision (79 FR 29960).

As previously discussed, the Agency received comments that were not in support 

of extrapolating the same precision qualification criteria for absolute fuel parameters, 

which is based on published method repeatability (r) of the applicable fuel parameter 

times 1.5 and dividing by 2.77, to precision criterion of method defined parameters. As 

previously explained, these commenters stated that the precision criteria of method 

defined parameters are sensitive to the matrix of the fuel. This degree of sensitivity to 

fuel matrix effects is different for different test methods, techniques, and instrumentation 

that claim to measure the same method defined fuel property. Also, commenters 

recommended that the precision standard deviation qualification criterion for method 

defined parameters be based on a TPI as described in ASTM D6792.507 As previously

explained, the Agency has evaluated ASTM D6792 and agrees that the precision 

qualification criterion for method defined parameters be based on a TPI as described in 

ASTM D6792. Thus, in a change from proposal, we are finalizing requirements for 

reference instruments to meet precision qualification requirements as discussed above for 

their respective fuel parameter in Table VI-4 through Table VI-9 of this preamble.

Second, we proposed that reference instruments must be shown to be near the 

middle of the distribution of the ILCC program for at least the five months prior to 

application.508 We proposed requiring laboratories to specifically compute the difference 

between the instrument's average measurement of the fuel closest to the applicable 

standards (or to the average value for the fuel type in the complex model) and the robust 

mean for that fuel obtained by all of the non-outlier labs in the program. We further 

 

506 Where the standard deviation is estimated from a sample of the population (formula uses “N-1” in the 

denominator).

507 ASTM D6792-07, entitled, “Standard Practice for Quality System in Petroleum Products and Lubricants 

Testing Laboratories”.

508 There may be an alternative to this measure to be had from the D6299-10e1 calculations, so that we 

could require that the instrument be doing SQC and having a certain quality of performance. This could 

reduce the burden of calculations and align this requirement better with the NTTAA.
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proposed that this difference be standardized by expressing it in robust standard deviation 

units. We also proposed that these standardized ILCC differences would be put into a

moving average with a span of, say, 5 months. We proposed to set the standard such that 

the instrument's moving average would be within the central 50% of the distribution of 

participating designated method labs. We explained that because a robust standard 

deviation is used by the ILCC program this percentage would have to be approximate. 

We further explained that such lab-specific qualification would be outside of the normal 

qualification of a lab for making regulatory measurements for certifying fuel and would 

pertain only to use of the instrument in certifying other methods. In essence, these 

designated method installations would serve as surrogates for the gravimetric standards 

that cannot be used in qualifying alternative methods for method-defined parameters (79 

FR 29960).

Both API and AFPM stated that this requirement would be feasible for a single 

entity wishing to qualify alternate test methods under ASTM D6708 by using a single 

reference installation; however, they described the requirement as overly restrictive in 

other instances. Based on a workup, provided as a separate attachment to their 

comments509, of the proposed requirements using ASTM D5599 Total Oxygen results on 

eleven RFG distributions, RFG1205 through RFG1303, they showed that less than fifteen 

percent of the participants met the proposed EPA requirement of staying within the 

central 50 percent for 5 successive exchanges. Therefore, they suggested a requirement of 

3 out of 5 successive exchanges staying within the middle 50 percent of the distribution 

of measurements on the ILCC program would be more realistically achieved in practice. 

After reviewing these comments and data, the Agency agrees that setting a requirement 

of 3 out of 5 successive exchanges to stay within the middle 50% of the distribution of 

measurements of the industry monthly ILCC program for at least five months is more 

appropriate and achievable as compared to 5 out of 5 successive exchanges staying 

within the middle 50% of the distribution of measurements of the ILCC for at least five 

months. Another commenter recommended the option of using other crosscheck 

programs besides those from ASTM, and suggested that EPA revise criteria for the 

reference installations at 40 CFR 80.47(k)(2) to also refer to use of commercially

available monthly ILCC. The Agency agrees that the regulated community should be 

able to use both commercially available and industry monthly ILCC, and has made this 

change to 40 CFR 80.47(k) to afford this flexibility. Therefore, in a change from 

proposal, and in response to these comments, the Agency is setting a requirement that a 

reference installation of the designated test method must be shown to be within the 

middle 50% of the distribution of measurements for 3 out of 5 exchanges of either the

industry or commercially available monthly ILCC program for at least five months.

 

509 For a description of workup and spreadsheet associated with these comments, see attachment No. 4 in 

Docket number EPA-HQ-OAR-2011-0135-4276-A5.pdf and attachment No. 5 in EPA-HQ-OAR-2011-

0135-4276-A6.pdf.
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Another commenter suggested that EPA should require applicants to submit 

control charts showing a record of in-control operation for at least five months provided 

that: 1) regular maintenance and/or re-calibration conducted during the 5 month incontrol qualification period is considered as part of in-control normal operation, and 2) 

the clock for the 5 month period does not re-start (in other words the system is still 

considered to be in-control) if an assignable cause for out of control is found, mitigated, 

and the system is brought back in-control during the period that the reference installation 

is attempting to meet the 5 month in-statistical-control requirement. The Agency agrees 

with these two conditions and in a change from our proposal, we are finalizing 

regulations that would allow systems meeting these two conditions to be in-control with 

respect to the 5 month in-statistical-control requirement. Finally, for reference 

installations, we proposed that the reference instrument must be shown to be in statistical 

control, as provided for in ASTM D6299-10e1, comply with applicable SQC procedures 

as well as have control charts showing a record of in-control operation for at least five 

months. We explained that while these requirements would likely impose a delay

between instrument setup and the ability to qualify as a reference installation we believed 

that any delay would be necessary to demonstrate the stability of these critically

important installations. We also reasoned that we expected no lack of facilities capable 

of meeting these standards considering the number of long-established installations of 

these designated methods. 

API and AFPM disagreed with this requirement and stated that summary statistics 

(mean and standard error = standard deviation / square root [no. of results]) from ILCC 

program data can be used as is, i.e., without imposing the reference installation criteria to 

conduct an ASTM D6708 assessment on VCSB alternate test methods, provided that the 

number of non-outlying results is greater than 16 for both designated and alternate 

methods. According to both commenters, this is the current de facto methodology for 

determination of ARV of check standards as specified in ASTM D6299, clause 6.2.2.1 

and Note 7. Both commenters also suggested that using ASTM D6299 for establishing 

ARV would be consistent with OMB Circular 119. They noted also that ASTM ILCC 

program data for the method-defined parameters of interest exceeds this number (16) 

significantly.

API and AFPM also commented that it is neither necessary nor statistically 

justified to apply the reference installation precision and middle 50 percent criteria to the 

ILCC program data for designated test method because the relevant ILCC program 

statistics are calculated using outlier-free data, and the number of data points is large, 

hence providing a better statistical sample of the laboratory population. According to 

them, the mean calculated using the full ILCC program outlier-free data set is a more 

accurate representation of the population parameter (μ) than the mean calculated using 

only the middle 50 percent. They noted the standard error for the arithmetic mean 

calculated using the full ILCC program data set is significantly reduced due to the square 

root [number of non-outlying results] term in the denominator for calculation of standard 

error. Both API and AFPM also urged EPA to clearly state that the use of ILCC 

program data as described above is suitable for an ASTM D6708 assessment of VCSB 
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alternate test methods. EPA agrees that the use of ASTM ILCC program data is suitable 

for an ASTM D6708 assessment of VCSB alternative test methods, provided that the 

number of non-outlying results is greater than 16 for both designated and alternate 

methods. In these situations where VCSB ILCP data is utilized during an ASTM D6708 

assessment, the reference installation criteria provided in the regulations will not apply, 

rather a VCSB will have the flexibility of utilizing the VCSB ILCC program data to 

conduct an ASTM D6708 assessment. The Agency has made these changes in the final 

regulations to reflect these comments.

Finally, API and AFPM noted that the current “robust” outlier treatment 

methodology for the ASTM CS92 ILCP program will be replaced with a statistically

more rigorous approach using the Generalized Extreme Studentized Deviation (GESD) 

technique. Thus, they suggested that EPA remove the term “robust” from the preamble 

and regulations wording. EPA agrees with the comment and has removed “robust” from 

the final regulations wording. 

e. Qualification Criteria for Designated Test Method Installations that are 

“Method-Defined” Parameters Instruments and Not Used to Qualify Other 

“Method-Defined” Methods

At proposal, we explained that refiners, importers and oxygenate blenders 

producing gasoline and diesel fuel are required to test these fuels to determine the levels 

of various specified parameters. A designated test method is associated with each 

parameter to be tested (except for sulfur concentration in ultra-low sulfur diesel fuel, 

which must meet performance-based requirements510) in 40 CFR part 80. Table VI-5 of 

the proposed rule preamble listed the fuel parameters and their corresponding designated 

test methods. We proposed that installations of designated methods must maintain 

records and meet certain statistical quality control requirements. We explained that 

requiring all installations of all methods, including existing designated method

installations, to implement statistical quality control, would likely suffice to homogenize 

and improve measurement quality in these already-stable and standardized methods (78 

FR 29961).

f. Qualification Criteria for Method Defined Parameter Instruments Other 

Than Designated Test Methods

With regard to method-defined parameters, the Agency today is finalizing two 

options for qualification of alternative test methods. The first option, known as the 

VCSB approach, allows for qualifying methods that have been sponsored and published 

by a voluntary consensus standards body, such as ASTM International. The second 

option, known as the non-VCSB approach, involves qualification for a laboratory that has 

developed its own analytical test method but has decided not to offer it for evaluation and 

 

510 See 40 CFR 80.580, 40 CFR 80.584 and 40 CFR 80.585.
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establishment through a VCSB-based organizational process. At proposal, we explained 

that both options would require the candidate method to have a precision criterion that is 

at least equal to that of the designated analytical test method (though not defined in 

precisely the same way). We also proposed to require that the alternative method must 

also be capable of close correlation with the designated method for the parameter such 

that the refiner may use the alternative method results to produce predicted designated 

method results that it can subsequently use in demonstrating compliance with the 

applicable fuel composition or performance standards (78 FR 29961).

Consistent with our proposal, we are finalizing the following criteria for both the 

VCSB and non-VCSB approaches to qualify method-defined instruments that are 

discussed in further detail below.

i. Qualification Criteria for VCSB Method-Defined Parameter Test 

Methods

For methods that have been sponsored and published by a VCSB, such as ASTM, 

we expect that at a minimum, the VCSB must have fully described the analytical test 

method, so that it is replicable in many different laboratories and its operation may be 

understood by a technician. (We continue to consider publication of a method by a 

VCSB organization such as ASTM as meeting this criterion.) The VCSB must have 

tested the candidate method in a round robin program against the designated method, 

must have published a determination that the method meets the criteria specified in the 

discussion below, and must have published the information necessary to correlate the 

alternative method to the designated method. Consistent with our proposal, a VCSBbased candidate alternative analytical test method need not be qualified separately in each 

laboratory that adopts it. This is because by the time such a test method has been through 

the extensive development process typically required by a VCSB, the method’s 

procedures would have been exhaustively described. At this point there will be little 

uncertainty about how the analytical test method is to be applied, and it will have been 

implemented in a variety of different laboratories and used on a variety of different types 

of fuels. Therefore, we continue to believe that the VCSB-based process gives EPA 

some confidence that the analytical test method is likely to be stable in use and can be 

implemented with very little ambiguity regarding instrumentation, materials, and 

procedures. Moreover, VCSB method evaluation protocols have been established; 

including a protocol for comparing methods provide means for establishing a VCSB 

alternative method’s precision parity with the designated method for the parameter and 

for determining whether the alternative method can be adequately correlated with the 

designated method.511 Further, consistent with our proposal, VCSB method-defined test 

methods must utilize ASTM D6708 to determine if a correlation equation is necessary.

 

511 ASTM D 6708-08, entitled, Standard Practice for Statistical Assessment and Improvement of Expected 

Agreement Between Two Test Methods that Purport to Measure the Same Property of a Material.
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ii. Qualification Criteria for non-VCSB Method-Defined Parameter 

Test Methods

Consistent with our proposal, a candidate method that follows the non-VCSBbased route for qualification must be qualified independently by each analytical 

laboratory that wishes to adopt the method. We proposed the following seven 

qualification criteria for non-VCSB method-defined parameter test methods.

First, the Agency proposed to require a complete operational description of the 

non-VCSB test method, as described above in Section VI.A.2.c.iii of this preamble. We 

explained that the operational description must be thorough enough that a person lacking 

expertise in the operation of the test instrument would be able to replicate its results.

Second, the Agency proposed that the candidate non-VCSB test method be tested 

on a range of fuels512 and by a qualified reference installation of the applicable designated 

test method.

Third, the Agency proposed that the specific laboratory using the candidate nonVCSB test method must statistically establish through application of ASTM D6708-08 

that the candidate method measures the same aspect of samples as the applicable 

designated test method.

Fourth, the Agency proposed to disqualify non-VCSB test methods with 

important sample-specific biases (matrix effects) that cannot be considered as random as 

determined by ASTM D6708-08. We explained that it was possible that a non-VCSB 

test method suspected by the applicant of being highly matrix-sensitive may be qualified 

on a narrowly circumscribed range of fuels (which must, meet the D6708 statistical 

variability criteria). In this situation, types of fuels used for qualification and the method 

that is to be approved must be specified in the method description. Fuels outside of this 

scope would have to be analyzed for regulatory purposes by some other method. The 

Agency believes that any restriction on the scope of fuels to be used in qualifying a 

method must be accompanied by a discussion of how the applicant plans to screen 

samples for conformity to the scope.

Fifth, the Agency proposed that precision qualification be conducted in the form 

of cross-method reproducibility of the candidate and applicable designated test method, 

where the “cross-method reproducibility” must be equal to or less than 70 percent of the 

published reproducibility of the applicable designated test method.

 

512 Fuels, either consensus named fuels or locally named reference materials, used must be typical of those 

to be analyzed by the facility in practice and must meet the data requirements (variability, etc.) of ASTM 

D6708-08.
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We explained that the Agency believes that when ASTM D6708-08 is used in this 

manner (without joint round robin data) the cross-method reproducibility (Rcm) output 

by the program is not really a reproducibility in the usual sense, but rather indicates the 

expected value with uncertainty of the differences between the designated method and 

qualification candidate method. We believe that when used this way, Rcm from ASTM 

D6708-08 is more analogous to a site precision than to an inter-laboratory

reproducibility. For a detailed description of cross-method reproducibility (Rcm) see 78 

FR 29962.

Sixth, the Agency proposed that the applicant would demonstrate, through the use 

of ASTM D6708-08, whether a correlation to the designated test method is necessary. 

We explained that ASTM D6708-08 could also be used to determine whether the 

candidate methods results are either null compared to the designated test method and 

thus, needs no adjustment or correlation, or whether some correction or correlation 

equation is required so the candidate method may predict designated method results. We 

proposed the use of ASTM 6708-08 for corrections, if it is determined that the candidate 

method requires such a correction to predict designated test method results. The Agency

proposed that the correction would be applied to the candidate instruments output to 

obtain measurements results for regulatory purposes.

Finally, we proposed to require that applicants for non-VCSB test methods secure 

an independent third party oversight and audit review of the data generated and used to 

qualify non-VCSB test methods. We proposed that the independent third party would 

provide an overall assessment of the analytical technique and methodology and discuss 

any limitations in the scope of the method, as well as attest that all requirements for nonVCSB test method qualification have been satisfied. The Agency explained that this 

requirement would provide additional assurance that a non-VCSB test method is found to 

be adequate in use for compliance (78 FR 29961-29962).

We received comments in support of the proposed qualification criterion for nonVCSB Method-Defined Parameters. One commenter recommended allowing third-party 

oversight service providers that have good working knowledge of ASTM D6708 and 

ASTM D6299 in addition to degrees in Chemistry or Statistics. Further, they believed 

that limiting the third party oversight qualification to only U.S. degree holders would 

exclude non-U.S. degreed subject matter experts with equivalent knowledge and 

qualification. They suggested that rule language be expanded to include non-U.S. 

equivalent degreed or industry recognized subject matter experts. Another commenter 

recommended professional chemical engineers with demonstrated experience in 

analytical techniques as an option to chemists and statisticians because, according to the 

commenter, chemical engineers have a strong background in chemistry, and based on 

trends within industry they would also have experience in statistical process control. The 

Agency agrees with these comments and has amended the final regulations to include 

chemical engineers and non-U.S. degreed subject matter experts with equivalent 

knowledge and qualifications as third party oversight service providers. Rule revisions 
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have also been made to reflect the recommendation that all of these candidates should 

also have a good working knowledge of ASTM D6708 and ASTM D6299.

Consistent with our proposal, the Agency today is finalizing the qualification 

criteria for non-VCSB method defined fuel parameters with the few changes in response 

to comments as discussed above.

g. Statistical Quality Control: How Can We Ensure that Test Methods 

Continue to Deliver Quality Measurement in Practice?

Today’s final action also includes a statistical quality control (SQC) program that 

must be applied to any analytical test method used in the regulatory programs covered by 

this final action. Consistent with our proposal, every laboratory that uses test instruments 

to measure fuel parameters to satisfy EPA’s reporting or recordkeeping requirements 

must implement and maintain a basic SQC program. Unlike the qualification criteria 

requirements, where only one set of essentially identical instruments implementing the 

same method in a laboratory must qualify, every laboratory must have a separate SQC 

program for each instrument used to make measurements for reporting or recordkeeping 

purposes.513

Consistent with our proposal, we are also finalizing requirements that provide 

implementation of a SQC program by a laboratory as a defense in any subsequent 

enforcement actions where measurements are in issue. Today’s requirements also reflect 

our proposal to adopt a subset of SQC procedures that are already widely in use from 

ASTM D6299-10e1. We continue to anticipate that the measures we are finalizing would 

not require the generation of much additional data by the laboratory that employs them 

and that the SQC program would improve the quality of measurement among those 

laboratories that adopt such measures. These SQC procedures used by laboratories 

would ensure that the test methods they have qualified and the instruments on which the 

methods are run yield results with appropriate accuracy and precision, e.g., that the 

results from a particular instrument does not drift over time to yield unacceptable values. 

The finalized minimum specific SQC requirements for laboratories for absolute 

parameters, VCSB-approved methods used to measure method-defined parameters, and 

non-VCSB proprietary methods used to measure method-defined parameters are 

discussed in further detail below.

 

513 Such SQC programs are already an established part of VCSB protocols for analytical laboratory 

operation (as indicated by such practices as ASTM’s D6299-10e1) and are likely to be part of most 

laboratories ”standard operating procedures.” Thus, such a requirement very likely adds little or nothing in 

the way of burden for most laboratories. Laboratories that lack such programs and would have to expend 

significant effort to create them are those most at risk for poor measurements and for which the effort is 

most easily justified.
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We proposed similar precision and accuracy SQC requirements for each 

instrument used to measure absolute and VCSB-approved and non-VCSB proprietary

methods for measuring method-defined parameters in the laboratory. We proposed that 

every instrument would test a quality control (QC) material514 either once per 20 

production tests or once per week and maintain both an “I” chart515 and an “MR” chart.516 

We proposed that any violation of the control limit would be investigated by laboratory

personnel, corrective action taken as required, and records kept of the incident for a 

period of 5 years. We also proposed allowing used of ASTM D6299-10e1 procedures for 

transitioning from one batch of QC material to another.

We also proposed use of Annex A1.9, entitled “Q-Procedure”, of ASTM D6299-

10e1 for validating new QC material. We proposed that when QC material is soon-to-bedepleted, that a new batch of QC material would be prepared and its value compared to 

the old QC material on a chart. We explained that the new batch of QC material would be 

tested concurrently with the soon-to-be-depleted old QC material. And the results would 

be plotted from the “old” and “new” QC materials on respective charts, and if no specialcause signals are noted, then the result for the new material would be considered valid 

(78 FR 29963-64). 517

We received comments in support of all these requirements with the exception of 

requirements for both QC verification and validation of new QC materials. One 

commenter recommended that test facilities conduct verification of new QC material 

three times a year rather than on a quarterly basis so that this requirement is aligned with 

ASTM International ILCC program sample cycle frequency. The Agency agrees with 

this comment and has made rule language changes to reflect that test facilities can 

conduct verification of new QC material three times a year in order to align this 

requirement with ASTM ILCC program sample cycle frequency. Additionally, the 

Agency envisions this change will help encourage the participation of ASTM 

Subcommittees in the PBATM approach for their respective alternative test methods.

One commenter noted that the Q-procedure in ATSTM D6299, which relates to 

the handling of QC material batch transition, is intended to be an alternative approach to 

the concurrent testing (overlap) protocol. They suggested the option of using either one 

of the two procedures, and not both the Q-Procedure and I-procedure as we had proposed. 

According to the commenter, the Q-procedure is technically equivalent to the I-

 

514 See ASTM D6299-10e1, paragraph 3.2.3 for a definition and Section 6 for guidance, selection, 

construction, handling, storage and use of reference material samples.

515 See ASTM D6299-10e1, section 7 and Section A1.5.1 for chart construction and usage, including criteria 

for deciding upon corrective action.

516 See ASTM D6299-10e1, Section A1.5.2 for chart construction and usage. Any exceedance of the control 

limit should be investigated.

517 See ASTM D6299-10e1, Annex A1.9 Q-Procedure. Procedures differ depending whether an I-chart, MR 

chart, EWMA chart, Q-chart or a combination of these charts are utilized by the laboratory.
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procedure. They also suggested that for sites opting to use the Q-procedure, the very first 

run on the new QC batch should be validated by either an overlap in-control result of the 

old batch, or by a single execution of an accompanying SRM. Then the new result would 

be considered validated if the single result of the SRM is within the established site 

precision (R’) of the ARV of the SRM. The Agency agrees that the Q-procedure is 

functionally equivalent to the I-procedure and that laboratories should be given the 

flexibility to use either of these two procedures instead of both procedures, as proposed. 

The Agency also agrees that for sites opting to use the Q-procedure, the very first run on 

the new QC batch should be validated by either an overlap in-control result of the old 

batch, or by a single execution of an accompanying SRM. The new result would be 

considered validated if the single result of the SRM is within the established site 

precision (R’) of the ARV of the SRM. In response to these comments, we have revised 

our proposed regulations to reflect these suggested changes.

We proposed requiring every instrument to test a commercially available 

gravimetric “SRM” (“check standard” as defined in ASTM D6299-10e1) on a quarterly

basis. We explained that the absolute difference between the mean of multiple back-toback tests of the SRM and the ARV of the SRM that is greater than 0.75 times the 

published reproducibility of the test method must be investigated by laboratory personnel, 

appropriate action taken, and records kept of the incident and investigation. We proposed 

to require that records of the SRM measurements and investigations into any exceedance 

of these proposed criteria must be kept for a period of 5 years. Additionally, we proposed 

to require laboratories to pre-treat and assess results from the check standard testing after 

at least 15 testing occasions518, construct “MR” and “I” charts519 with control lines, and 

maintain control charts, logging, investigating, and correcting underlying causes of any

control limit violations as discussed in ASTM D6299-10e1. We proposed to require that 

records of such incidents and the underlying control charts must be kept by the facility

for a period of 5 years. (78 FR 29963.)

One commenter suggested that the expanded uncertainty of the ARV should be 

incorporated into the accuracy qualification criterion as follows: Accuracy qualification 

criterion = square root [(0.75R)^2 + (0.75R)^2/L], where L = the number of single results 

obtained from different labs used to calculate the consensus ARV. According to the 

commenter, this is because the standard error of the ARV in the consensus-named fuels 

may not in all cases be negligible when compared to 0.75R. The Agency agrees with this 

comment and has incorporated the standard error of the ARV in the consensus-named 

fuel into the accuracy qualification criteria for determining when appropriate action 

should be taken during an SQC investigation.

 

518 See ASTM D6299-10e1, Section 8.2 (pretreatment) and Section 8.4 (assessment). Procedures differ 

depending upon whether a single check standard is used for multiple testing occasions or multiple check 

standards must be used.

519 See ASTM D6299-10e1, Section 8.4 and appropriate Annex sections for chart construction and guidance.
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Today, the Agency is also finalizing the Statistical Quality Control requirements 

for absolute fuel parameters, and VCSB-approved and non-VCSB proprietary methods 

that are used for measuring method defined parameters, as proposed. Consistent with our 

proposal, the Agency is also finalizing requirements allowing use of either the “I” chart 

or Q-procedure for validation of new check standards, and the incorporation of the 

standard error of the ARV in the consensus-named fuel into the accuracy qualification 

criteria for determining when appropriate action should be taken during an SQC 

investigation.

h. Agency Approval Options

We proposed to require qualification of only proprietary analytical test methods, 

i.e., non-VCSB test methods for fuel parameters. We also sought comment on whether 

we should require qualification of all analytical test methods for fuel parameters. The 

following section contains a discussion of our proposal, as well as our final decision 

based on the comments received on our proposal.

At proposal, we explained that the approach to performance-based qualification of 

test methods would go considerably beyond the minimum requirements of the National 

Technology Transfer and Advancement Act of 1995 in providing flexibility of method 

choice, and accomplish performance-based qualification without compromising 

measurement quality. We also reasoned that the primary tools for achieving the latter 

objective are laboratory-specific qualification of method installations and a requirement 

for across-the-board SQC. We also explained that while EPA would benefit from PBMS, 

when finalized, by no longer having to evaluate new alternative measurement 

methodologies, this benefit would likely not offset the substantial and unpredictable 

resource costs involved in administering a qualification process and providing 

infrastructural support for laboratories’ SQC programs (78 FR 29964-65).

We proposed qualification requirements for only non-VCSB test methods for fuel 

parameters. We also proposed excluding designated test methods that have been in 

operation 6 months prior to finalizing this rule, as well as test methods that are developed 

by VCSBs, like ASTM International or the International Organization for Standards 

(ISO) from qualification requirements. We had also proposed subjecting laboratories that 

develop test methods but decide not to offer them for evaluation and establishment 

through a VCSB-based organizational process to qualification requirements.520 We 

proposed that all test methods subject to qualification requirements must be qualified 

independently by each analytical laboratory that wishes to adopt the test method. We 

 

520 Reasons for not submitting a local method for VCSB evaluation may include the proprietary nature of 

software or apparatus or the fact that the method is highly matrix-sensitive and not likely to perform 

consistently when used to analyze fuels with widely varying properties. EPA recognizes that matrix 

sensitivities may be subtle and methods with such characteristics may have been sponsored and published 

by VCSB’s.
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explained that this is because such a test method would not have been shown to be 

capable of accurately measuring the fuel parameter in different laboratories and across a 

variety of fuel matrices. We also explained that the precision for the candidate analytical 

test method must be established by a medium-term series of measurements on production 

fuels, the workability of the test method must be verified by at least on other laboratory, 

and its accuracy must be demonstrated by direct correlation to the designated analytical 

test method for the particular fuel parameter.

For test methods that have been sponsored and published by a VCSB such as 

ASTM or ISO, we proposed that the test method must be fully described so that it is 

replicable in many different laboratories and so that its operation may be understood by a 

technician. We also proposed that the VCSB must have tested the candidate test method 

in a round robin program against the designated test method, must have published a 

determination that the test method meets the performance criteria as discussed, and must 

have published the information necessary to correlate the alternative test method to the 

designated test method.521

We also proposed that a VSCB-based alternative test method need not be 

qualified separately in each laboratory that adopts it. We explained that this is because 

the test method’s procedures would have been exhaustively described by the time the 

VCSB-based candidate alternative test method has been through the extensive 

development process typically required by a VCSB. We also reasoned that at this point 

there would be little uncertainly about how the analytical test method is to be applied, and 

it would have been implemented in a variety of different laboratories and used on a 

variety of different types of fuels. We continue to believe that the VCSB-based process 

gives some confidence that the analytical test method is likely to be stable in use and can 

be implemented with very little ambiguity regarding instrumentation, materials, and 

procedures. As also explained at proposal, VCSB method evaluation protocols have been 

established, including a recently developed protocol for comparing methods, which 

provide means for establishing a proposed VCSB alternative method’s precision parity

with the designated method for the parameter522 and for determining whether the 

alternative test method can be adequately correlated with the designated test method.523

We also recognized that imposing qualification requirements on existing test 

methods developed by a VCSB without adequate lead time may be problematic. We thus 

 

521 This first approach assumes that a single such equation can be used for all labs using the method, an 

assumption that may not always hold true. The more detailed discussion of the two approaches that follow 

s this introduction explores this problem.

522 ASTM D6708-08, entitled, Standard Practice for Statistical Assessment and Improvement of Expected 

Agreement Between Two Test Methods that Purport to Measure the Same Property of a Material.

523 ASTM D6708-08, entitled, Standard Practice for Statistical Assessment and Improvement of Expected 

Agreement Between Two Test Methods that Purport to Measure the Same Property of a Material.
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proposed to give methods published and in operation upon publication of the Tier 3 

proposed rule (May 21, 2013) a grace period of one year from the effective date of a final 

rule to comply with today’s requirements.

We also proposed to exempt existing (i.e., in use for six months prior to 

publication of the proposal) installations of designated test methods that are methoddefined parameters from the qualification requirement. We reasoned that these 

installations were stable and capable methods in relatively experienced hands because 

they are already being used to certify fuels, and that requiring their qualification could be 

disruptive and burdensome to both their operators and to whomever manages the 

qualification process. We further reasoned that such installations would not benefit 

tangibly from this rule (as by obtaining access to a desired new method), but would 

nevertheless bear a newly-imposed burden.

We also proposed record keeping and retention requirements for both VCSB 

alternative and non-VCSB test methods. Parties would need to maintain qualification 

records for demonstrating compliance for a period of 5 years after they cease use of the 

particular test method. Parties must also maintain a complete description of the test 

method and data with statistical analysis that supports its qualification.

We also sought comment on whether the Agency should require qualification of 

all analytical test method for the fuel parameters of 40 CFR part 80. This would include 

each designated test method, all alternative test method currently allowed by our 

regulations, as well as any other analytical test method regardless of whether the test 

method was developed by a voluntary consensus standards based organization, like 

ASTM, or if it is a proprietary analytical test method, that is, non-VCSB test method.

We recognized that imposing the qualification requirement on existing and 

operational installations of all methods without adequate lead time may be problematic. 

We thus proposed to give laboratories (i.e., those in operation when the proposal was 

published (May 21, 2013)) a grace period of one year from the effective date of the final 

rule prior to complying with the requirements being finalized in today’s rule. We 

explained that we believed that a year should be enough time to determine whether an 

existing test method is likely to qualify or to adopt and qualify a replacement test method 

if it should fall short. New installations of previously accepted methods, including 

alternatives, would be required to qualify their laboratory before being put into service 

just like all other installations of new test methods in a laboratory (78 FR 29964-29965).

All comments received were in support of our proposal to require qualification of 

only non-VCSB test methods for fuel parameters. We also received several comments 

requesting a compliance period of 18 months from the effective date of this rule rather 

than one year. According to commenters, this period of time was needed by the regulated 

community to help ensure adequate lead time to implement this new performance based 

measurement system program especially because there of expected modifications based 

on comments that were received on the proposed PBMS requirements. Thus, there will 
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be a need for further clarification and implementation guidance beyond what was 

proposed and finalized today. Some commenters noted the discrepancy between the 

preamble and regulatory text as it related to the proposed exemption for installations of 

designated test methods of method-defined parameters that were in use six months prior 

to publication of the proposed rule. Consistent with our proposal, the Agency today is 

finalizing requirements for qualification of only non-VCB test methods for fuel 

parameters, as proposed. We are also finalizing as proposed the exemption of existing 

(i.e., in use for six months prior to May 21, 2013) installations of designated test methods 

from today’s qualification requirements. Further, in response to comments and in a 

change from our proposal, we are now providing a compliance period of 18 months from 

the effective date of this final rule for when these performance based analytical test 

methods measurement system requirements at 40 CFR 80.47 will be effective.

3. Downstream Pentane Blending

Today’s action finalizes provisions to allow blender grade pentane to be blended 

into previously certified gasoline (PCG) downstream of a crude oil refinery.524 These 

provisions will become effective [INSERT DATE 60 DAYS AFTER PUBLICATION IN 

THE FEDERAL REGISTER]. These provisions that are being finalized today are 

similar to the long standing provisions for blending butane into gasoline at 40 CFR 80.82, 

with additional provisions to provide adequate compliance assurance. 

Refiners are not able to produce gasoline or BOBs that are as close to the 

applicable maximum volatility (RVP) standard in a given area as what can be achieved at 

a terminal through RVP trimming due to spatial and temporal considerations regarding 

the shipment of gasoline to terminals. Butane is currently blended into PCG downstream 

of the refinery in order to trim RVP levels closer to the applicable maximum RVP 

specifications. Butane blenders are required to test the finished gasoline they produce to 

demonstrate compliance with the maximum RVP requirements. Testing for RVP is 

quick, and requires relatively inexpensive and easy to operate equipment. Hence, RVP 

testing can be accommodated at a terminal where small (tank truck sized) batches are 

continually produced by blending for delivery to retail stations. Testing for other fuel 

parameters such as sulfur and benzene content requires more costly and technically 

demanding equipment that cannot readily be accommodated at a terminal. Such testing 

can also not be completed in a time frame that is compatible with the need for terminals 

to quickly move product to retailers in order to maintain adequate supply for consumers. 

These considerations informed the Agency’s prior decision to allow butane blenders to 

primarily rely on testing conducted by the butane supplier (and the producer of the PCG) 

to demonstrate compliance with gasoline fuel quality requirements other than maximum 

 

524 Blender grade pentane refers to pentane that meets the specifications for either commercial grade or 

non-commercial grade pentane discussed below and as such may be added to previously certified gasoline 

by pentane blenders meeting the requirements finalized today. .
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RVP.525 The same considerations exist today regarding blending pentane into PCG. 

Therefore, we are finalizing provisions to allow pentane blenders to also primarily rely on 

testing conducted by the pentane producer or importer and the producer of the PCG to 

demonstrate compliance with gasoline fuel quality requirements other than maximum 

RVP. We are requiring that the test results on the pentane be generated by the producer 

or importer of the pentane because we believe that it is necessary to identify a specific 

party that must register with EPA and be responsible for the pentane quality 

requirements. 

The fuels regulations place primary responsibility for sampling, testing, reporting 

and assuring that gasoline meets applicable fuel standards on refiners. The flexibility that 

this rule provides to butane blenders and pentane blenders does not shift this primary

compliance obligation. The rule does, however, provide a limited flexibility for refiners 

who add these blendstocks to previously certified gasoline. The agency has provided this 

limited flexibility because of the unique nature of these blendstocks, and because of 

additional compliance requirements that are imposed on the manufacturers of these 

blendstocks and the refiners who use these blendstocks. Refiners who use the special 

allowance for butane and pentane blending will remain liable for any fuel quality

violations, but will be able to rely on sampling and testing from the butane and pentane 

manufacturer, if all of the requirements of the regulations are met. All other refiners, 

including blender-refiners, must comply with all of the applicable sampling, testing, 

reporting recordkeeping and fuel quality standards, and may not rely on test results from 

blendstock suppliers. 

As discussed in Section V.C. of today’s preamble, the current butane sulfur cap 

will also apply to blender grade pentane blended into gasoline by until the 

implementation of today’s Tier 3 sulfur requirements, when a 10 ppm sulfur cap will 

apply to both butane and pentane blended into gasoline. The benzene, olefins, and 

aromatics specifications for “commercial grade” and “non commercial grade” blender 

grade pentane discussed below are similar to the requirements for butane. 

We received comments in favor of our proposal to allow pentane blending into 

PCG. During our discussions with stakeholders following the proposal and from the 

review of public comments, we became aware of additional potential issues associated 

with assuring the quality of pentane for gasoline blending beyond those that exist for 

butane.526 In response to comments and to further limit variability in pentane quality, C6 

and higher hydrocarbons in pentane blended into gasoline must be limited to 5 volume 

percent or less. We were also made aware of the possibility that parties that handle 

 

525 Regulation of Fuels and Fuel Additives: Modifications to Standards and Requirements for Reformulated 

and Conventional Gasoline Including Butane Blenders and Attest Engagements; Final Rule, December 15, 

2005, 70 FR 74552. 

526 See the Summary and Analysis of Comments for this rule for a detailed response to comments on the 

pentane blending provisions finalized today.
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natural gasoline liquids (NGL) might misinterpret the pentane blending provisions 

finalized today to apply to natural gas liquids. A pentane stream for gasoline blending 

does not currently exist, and there are currently varying definitions of NGL, which is 

sometimes referred to pentanes-plus. There is also concern about potential contamination 

if the same equipment is used to transport blender grade and NGL. Today’s rule finalizes 

the following additional requirements, that will preclude potential confusion of NGL with 

blender grade pentane, help ensure that the quality of blender grade pentane is maintained 

throughout the distribution system, and facilitate EPA enforcement and compliance 

assurance of the quality requirements for blender grade pentane.

First, producers and importers of pentane for gasoline blending must register with 

EPA. Such registrations must include sufficient information to demonstrate that the 

producer or importer will be capable of producing or importing blender grade pentane 

meeting today’s quality specifications and that contamination during distribution to the 

pentane blender can be adequately limited. Second, producers and importers of pentane 

for gasoline blending must test each batch of blender grade pentane to demonstrate that 

the quality requirements are met. Third, producers and importers of pentane for gasoline 

blending must submit an annual report to EPA that includes batch test data and 

information on the volume produced or imported. These requirements will enable EPA 

to perform effective oversight of entities that produce pentane for use by pentane 

blenders. 

Fourth, pentane blenders must use only blender grade pentane from registered 

producers or importers. We believe that this requirement will provide additional 

assurance that pentane blenders are obtaining product only from legitimate producers. 

Fifth, pentane blenders must conduct periodic quality assurance testing on both the 

commercial grade pentane and the non-commercial grade pentane that they receive. 

Sixth, we are requiring a more frequent sampling frequency than is required for butane. 

For commercial-grade pentane, pentane blenders must sample and test once for every 

350,000 gallons of pentane received, or once every three months, whichever is more 

frequent. For non-commercial-grade pentane, pentane blenders must sample and test 

once for every 250,000 gallons of pentane received, or once every three months, 

whichever is more frequent. We believe that the heightened level of concern regarding 

assuring the quality of pentane used by downstream blenders warrants these additional 

requirements. 

Finally, we are finalizing specific product transfer document and recordkeeping 

requirements for parties that produce and take custody of pentane for gasoline blending. 

Entities in the distribution chain for blender grade pentane must maintain records of their 

quality assurance activities to manage contamination while blender grade pentane is in 

their custody. We proposed amendments to 40 CFR 80.79 to address the liability and 

prohibited activities for entities in the blender-grade pentane distribution system. During 

our review of the regulations finalized today, we noted that such provisions are already

covered under existing regulations that pertain to entities in the distribution system for 
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butane used by downstream butane blenders as well as other parties. Therefore, we are 

not finalizing the proposed amendments to 40 CFR 80.79. 

A party that blends pentane into gasoline is a refiner, similar to butane blenders. 

Similar to the butane blending provisions, pentane blending will not be allowed into RFG 

or RBOB from April 1 through September 30, or into any RFG or RBOB that is 

designated as VOC-controlled. Like butane blenders, pentane blenders must test the 

finished gasoline to ensure that the applicable volatility requirements are met. Consistent 

with the requirements for butane blenders, pentane blenders will not be subject to other 

sampling and testing requirements that would otherwise apply to a refiner, provided that 

they use blender grade pentane that meets today’s specifications and conduct today’s 

specified quality assurance practices.

Testing to demonstrate compliance with gasoline compositional requirements 

other than maximum RVP will not be required for pentane blender provided that the 

blender has product transfer documents from the supplier that demonstrate the pentane is 

“commercial grade”. Until December 31, 2016, commercial grade pentane is defined as 

pentane that test results demonstrate is 95 percent pure and has the following properties: 

sulfur ≤ 30 ppm, benzene ≤ 0.03 volume percent, olefins ≤ 1.0 volume percent, aromatics 

≤ 2.0 volume percent, and C6 and higher hydrocarbon content ≤ 5.0 volume percent. 

Beginning January 1, 2017, a sulfur standard of ≤ 10ppm will apply while the other 

specifications for commercial grade pentane will remain unchanged. Product transfer 

documents from the supplier demonstrating the pentane is “non-commercial grade” may

also be used to demonstrate compliance with gasoline quality requirements other than 

volatility. Until December 31, 2016, non-commercial grade pentane is pentane that test 

results demonstrate as having the following properties: sulfur ≤ 30 ppm, benzene ≤ 0.03 

volume percent, olefins ≤ 10.0 volume percent, aromatics ≤ 2.0 volume percent, and C6 

and higher hydrocarbon content ≤ 5.0 volume percent. Beginning January 1, 2017, a 

sulfur standard of ≤ 10ppm will apply while the other specifications for non-commercial 

grade pentane will remain unchanged. As discussed above, producers and importers of 

pentane for gasoline blending must test each batch of finished gasoline to demonstrate 

compliance with these quality requirements.

The pentane parameter testing that is required of pentane producer/importers and 

pentane blenders must be conducted using test procedures that have been approved by the 

Administrator. No such test procedures are currently approved. As part of their 

registration requirements, pentane producers and importers must specify the test 

procedures that they will use to demonstrate compliance with the pentane quality

requirements finalized today. EPA will continue to work with industry in establishing 

test procedures for use in meeting pentane testing requirements. 

We believe that the butane blending provisions have reduced the burden of 

compliance with EPA gasoline quality requirements. We anticipate that expanding these 

provisions to allow pentane to be blended into gasoline will further reduce the burden of 

compliance. The requirement that final blends must comply with maximum gasoline 
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volatility requirements will ensure that the flexibility to conduct downstream RVP 

trimming will not reduce the environmental benefits of EPA’s gasoline quality

requirements. Due to its lower volatility compared to butane, larger volumes of pentane 

than butane can be blended into gasoline while still meeting the gasoline RVP standards. 

Thus, allowing pentane to be blended into gasoline downstream of the refinery may

displace butane blending. Since pentanes have a lower boiling point than butane, this 

could result in some environmental benefit from reduced vehicle evaporative emissions. 

A prominent butane blender stated that allowing pentane blending would provide an 

opportunity to increase domestic gasoline supply which in turn could help reduce 

gasoline prices. 

One commenter requested that the blending flexibility for pentane be extended to 

other gasoline range hydrocarbons such as heavy naptha. We disagree. We are not 

expanding today’s provisions beyond pentane. Pentane is a clean burning alkane like 

butane. The only concern with respect to the effect of downstream pentane and butane 

blending on vehicle emissions can be addressed through compliance with gasoline 

maximum volatility requirements. Less is known about the potential impacts on vehicle 

emissions of the downstream blending of blendstocks other than butane and pentane. We 

note that such blendstocks can still be utilized by refiners. 

Allowing blending of heavier boiling range hydrocarbons, such as heavy naptha, 

would also likely raise additional compliance assurance issues. Similar to butane, 

blender grade pentane requires special pressure vessels for transport, storage, and

blending into gasoline due to its relatively high vapor pressure / boiling point.527 These 

special equipment and handling needs present a significant barriers to entry into the 

pentane blending market, thereby limiting the potential number of parties engaged in the 

market. The substantial investments needed for such special equipment also provides 

assurance that parties engaged in the pentane blending market will be motivated to 

comply with EPA requirements. These factors make us confident that the compliance 

assurance requirements finalized today are sufficient to support provisions for pentane 

blending. On the other hand, in the case of heavier hydrocarbons that are liquid under 

ambient conditions, gasoline handling equipment could be used. This would greatly

multiply the number of potential parties that could supply product to downstream 

blenders, thereby substantially increasing compliance assurance concerns. Therefore, we 

are not finalizing provisions for downstream blending other than those for pentane at this 

time.

4. Acceptance of Top Tier Deposit Control Test Data

Today’s action finalizes the proposed amendments to EPA’s gasoline deposit 

control regulations to accept test data collected for the industry-based “Top-Tier” deposit 

 

527 The boiling point of pentane is ~ 97° F and butane is ~30° F.
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control program as demonstration of compliance with EPA’s intake valve deposit (IVD) 

and fuel injector deposit (FID) control requirements. The “Top Tier” deposit control 

gasoline standards developed by four major automakers are based on the premise that a 

more robust level of the control of vehicle engine and fuel systems beyond that provided 

by the EPA deposit control requirements is desirable and necessary for current vehicle 

technology.

528

 Several major gasoline marketers have adopted Top Tier for their 

gasoline. It is widely accepted that conformance with the Top Tier IVD and FID control 

testing requirements is more challenging than complying with the standard EPA IVD and 

FID testing requirements. Accepting IVD/FID test data that complies with the Top Tier 

requirements in place of the standard EPA IVD/FID testing requirements will provide 

significant savings to industry from reduced deposit control testing while maintaining the 

emissions benefits of EPA’s gasoline deposit control program. These changes are being 

codified in the regulations at §§80.161(b), 80.163(a)(1)(iii), 80.164(a), 80.165, 80.167(a), 

80.176, and 80.177.

The comments we received were in favor of the proposal to accept test data that 

demonstrates compliance with the Top Tier program as alternative compliance data under 

EPA’s deposit control program. Chevron stated that their extensive experience with 

deposit control and related vehicle/engine performance testing, combined with the vast 

body of technical literature on the subject, shows that compliance with Top Tier IVD/FID 

requirements provides improvements in emissions and performance compared to fuels 

with deposit control additive levels that merely meet EPA’s deposit control requirements. 

Chevron identified a typographical error in the proposed regulations to codify the Top 

Tier testing requirements at §80.177(b)(1)(iv). The proposed regulations stated that test 

fuel used in IVD testing must contain no less than 240 ppm sulfur. This error is corrected 

in the regulations finalized today to state that test fuel used in IVD testing must contain 

no less than 24 ppm sulfur, consistent with the Top Tier deposit control standard.

5. Potential Broader Regulatory Streamlining Through Program 

Restructuring

The current set of fuel regulations is the result of programs that have been 

established over the years to reduce emissions from mobile sources. These programs 

include gasoline volatility (RVP), reformulated gasoline and anti-dumping, sulfur control 

(which today’s Tier 3 program will revise), mobile source air toxics (MSAT1), benzene 

control (MSAT2), and the renewable fuel standards (RFS). Most of these regulations 

have been amended numerous times.

The RFG and anti-dumping regulations in particular contain some of the more 

extensive requirements on sampling, testing, and reporting. They also have some of the 

more stringent restrictions on gasoline use (e.g., restricting where fuel produced can be 

 

528 The industry-based Top Tier deposit control program is discussed at http://www.toptiergas.com/
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sold, what it may be commingled with, etc.). EPA used the RFG and anti-dumping rules 

as the foundation for many aspects of subsequently developed fuel regulatory programs. 

However, the subsequent rules, considered as a whole, have supplanted most of the RFG 

and anti-dumping standards. For this reason, we proposed to streamline the regulations 

in several places as described above. Initial discussions with fuel industry representatives 

have indicated that a comprehensive review of the complete set of fuel regulations 

contained in 40 CFR parts 79 and 80 (“Registration of Fuels and Fuel Additives” and 

“Regulation of Fuels and Fuel Additives,” respectively) of the Code of Federal 

Regulations could lead to further streamlining of the regulations beyond the streamlining 

provisions being finalized today. EPA expects that further streamlining would result in 

more efficient and less costly compliance determinations for affected parties while 

maintaining the environmental benefits of the programs. However, in many cases such 

changes could require not just the removal or streamlining of existing provisions but also 

the replacement of several provisions with new, less onerous ones that require further 

development, notice and comment. We intend to continue to seek comment in future 

actions on potential areas in the fuel regulations that may benefit from such a more 

comprehensive streamlining effort. For example, it may be possible for the RFG VOC 

standard to be met if a sufficiently stringent RVP level is attained. Under this scenario, 

sampling and testing requirements at the refinery would be reduced. Another potential 

scenario could involve consolidation of some RFG and anti-dumping rules; for example, 

a single set of rules governing the treatment of downstream ethanol blending and in-use 

surveys could provide greater efficiency and flexibility regarding fuel distribution.

We received a number of comments supporting the concept of further 

streamlining in 40 CFR parts 79 and 80, including suggestions for additional areas of the 

regulations to consider in the future.

B. Engine, Vehicle and Equipment Programs Amendments

We are amending several regulatory requirements for motor vehicles and other 

types of vehicles and engines. These changes are intended to align with the Tier 3 

standards and to make various adjustments and corrections to the regulations. We are 

also removing large portions of obsolete regulatory text and updating cross references 

accordingly. 

1. Fuel Economy Labeling

EPA adopted updated fuel economy labeling requirements in 40 CFR part 600 on 

July 6, 2011.529 The label displays a smog rating based on relative emission rates for 

certified vehicles. With new Tier 3 standards, this rating scale becomes less useful, since 

the Tier 3 standards disallow certification to half of the existing smog ratings. We are 

therefore adopting a new transitional smog rating scale starting in model year 2018. 

 

529 76 FR 39478 (July 6, 2011). 
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Manufacturers choosing to transition to the Tier 3 NMOG+NOX standards based on a 

percentage phase-in may continue to meet Tier 2 standards for the “phase-out” fraction of 

the fleet through model year 2020, but must use a new smog rating scale that lines up, to 

the extent possible, the Tier 2 standards with the new Tier 3 scale. We believe it is 

appropriate to shift to the new transitional smog rating scale in model year 2018 to reflect 

the start of Tier 3 program for the majority of vehicles. 

The smog rating scale ranges from 1 to 10. The federal Tier 3 program comprises 

seven different NMOG+NOX emission certification levels. In addition, the California 

ZEV program for 2018 and later model years includes a unique TZEV category, which 

falls between a ZEV (Bin 0) and a SULEV20 (Bin 20), resulting in a total of eight 

emission standards.530 EPA received comment asking that we develop appropriate 

ratings that account for both the exhaust certification and all-electric range of TZEV 

vehicles. EPA plans to develop guidance for smog ratings for TZEV vehicles in its 

annual fuel economy guidance letter. Therefore we are not finalizing a smog rating for 

California TZEV vehicles at this time. As proposed, we are omitting rankings 2 and 4 to 

help convey the larger absolute differences in the g/mile standards between Bins 70 and 

125 and Bins 125 and 160. 

We are also adjusting the scale again in model year 2025, once the Tier 3 

standards are fully implemented, so that, the middle of the scale (a smog rating of 5 or 6) 

is equivalent to the fleet average standard of 0.030 g/mile for NMOG + NOx, consistent 

with the fuel economy and greenhouse gas rating. 

We revised the regulations slightly after the proposal to accommodate the 

presence of LEV III vehicles in 2017 and earlier model years.

2. Removing Obsolete Regulatory Text

EPA regulations for highway and nonroad engines, vehicles, and equipment in 

many cases apply for a range of model years before being replaced by a new set of 

standards, requirements, and other provisions for implementing a program that changes to 

reflect technological innovation, changing environmental needs, new business dynamics, 

and other factors. 

We are taking steps in this rulemaking to remove substantial portions of 

regulatory text that no longer have any regulatory significance, generally because they

have been superseded by newer provisions. In many cases, this simply involves 

removing paragraphs or sections related to certifying products that no longer apply to 

2004 or newer model years. In other cases, we can remove whole subparts that apply 

only to engines and vehicles that have reached the end of their useful lives for the 

purpose of regulation. For example, the in-use regulations from 40 CFR part 86, subpart 

 

530 http://www.arb.ca.gov/regact/2012/zev2012/fro2rev.pdf
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H, applied only for 1993 through 2003 model year light-duty vehicles, light-duty trucks, 

and medium-duty passenger vehicles. Also, the National LEV standards in 40 CFR part 

86, subpart R (and in Appendix XIII through XVIII of part 86), applied only for 1999 

through 2003 model years. These subparts, and references to that content, can be 

removed from the CFR.

Similarly, the provisions of 40 CFR part 86, subpart A, applied to light-duty

vehicles only through model year 2000 for light-duty vehicles and model year 2004 for 

light-duty trucks and chassis-certified heavy-duty vehicles. Much of that subpart 

continues to apply for heavy-duty engines, so the obsolete portions must be removed 

more selectively. We are removing substantial portions of 40 CFR part 86, subpart A, to 

omit text that applies only for light-duty vehicles or light-duty trucks, and additional 

portions that do not apply for any 2004 or newer model years. 

There are also instances where we are streamlining the organization of regulatory

sections in 40 CFR part 86. For those places where there is a new section for a given 

model year where all the old provisions continue to apply, and the new section introduces 

a narrow additional provision, we are copying the new paragraph into the section for the 

older model-year provisions, with descriptive language in place to say when the new 

provision applies as appropriate. This consolidation allows us to take out numerous 

sections that can lead to confusion for the reader. 

The following sections describe additional changes to remove material.

a. Certification Short Test and I/M Provisions

Inspection and maintenance (I/M) programs have been implemented by state and 

local governments for many years. These programs have been effective at identifying 

vehicles that need some kind of repair to restore the performance of a vehicle’s emission 

control system. In that context, they have also provided useful information to facilitate 

warranty coverage where defective components or systems were still covered by the 

manufacturer’s warranty, as required by section 207 of the Clean Air Act. In 1993, EPA 

adopted a requirement for the certification short test (“CST” or “cert short test”).531 The 

purpose of the cert short test was to correlate the vehicle manufacturer’s certification and

I/M testing. Under this approach, the vehicle manufacturer certifies that a properly 

maintained and operated vehicle will pass I/M testing. When such a vehicle fails I/M 

during the warranty period, the manufacturer is responsible for the cost of repairs 

necessary to correct the problem so the vehicle can pass the I/M test. 

EPA adopted requirements in 1993 for manufacturers to design and build their 

vehicles with OBD, which provides performance feedback for evaluating whether 

emission control systems are functioning properly. This rule, combined with fleet 

 

531 58 FR 58382 (November 1, 1993).
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turnover, has resulted in vehicles subject to I/M being equipped with OBD. The standard 

protocol for I/M programs now depends on the OBD system instead of tailpipe tests to 

determine which vehicles need maintenance. Since vehicle manufacturers have to certify

the performance of OBD systems as part of the certification process, the use of OBD for 

I/M testing also provides a basis for determining that emission repairs are covered by the 

manufacturer’s warranty, when necessary. For many years, manufacturers have 

submitted a compliance statement for certification instead of submitting data to 

demonstrate that they meet the standards associated with the cert short test. Since 

emission measurements are no longer part of any standardized I/M testing, it has become 

clear that OBD systems have completely replaced the cert short test as the means of 

making warranty determinations for I/M testing. We are therefore entirely removing the 

cert short test standards and test procedures from 40 CFR part 86, subparts O and S, and 

similarly removing the emission measurement procedures from 40 CFR part 85, subpart 

W.

The remaining regulatory text in 40 CFR part 85, subpart W, relates only to the 

role of OBD testing in the determination of manufacturers’ warranty obligations resulting 

from I/M testing. In addition to removing material that no longer applies based on model 

years, we are updating this remaining text in two ways. First, we are expanding the scope 

to include medium-duty passenger vehicles since these vehicles are now subject to both 

OBD certification requirements and I/M testing. Second, we are replacing all citations to 

SAE reference procedures with a cross-reference to 40 CFR 86.1806, which accounts for 

the relevant OBD reference procedures. This avoids the possibility of changing the 

certification procedures in a way that departs from the I/M and warranty provisions. 

Since these programs are paired, there will never be a need to specify different reference

procedures for the two programs.

b. Testing for Heavy-Duty Highway Engines

We recently completed the migration of test procedures for heavy-duty highway 

engines from 40 CFR part 86, subpart N, to 40 CFR part 1065. Now that these 

manufacturers are all relying on the new test procedures, we are eliminating the 

regulatory provisions that no longer apply. This involves large portions of text in 40 CFR 

part 86, subpart N, that have been superseded by analogous material in 40 CFR part 1065, 

such as analyzer specifications, calibration procedures, calculation methods, and fuel 

specifications. The obsolete text also included several references to 40 CFR part 86, 

subpart D, which we will also no longer print in the CFR. 

We are keeping regulatory provisions in 40 CFR part 86, subpart N, that serve as 

the “standard-setting part” for matters related to testing, such as the duty cycles and notto-exceed test procedures. These provisions are unique to heavy-duty highway engines 

and are therefore not suitable for the general test specifications in 40 CFR part 1065. We 

will eventually migrate these remaining provisions to 40 CFR part 1036, where we 

already describe the greenhouse gas emission standards and certification requirements for 

heavy-duty highway engines.
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In the case of testing in-use engines that were originally certified using the 

procedures in 40 CFR part 86, subpart N, we are including a regulatory provision to 

allow EPA and manufacturers to continue to use the original certification procedures as a 

pre-approved alternate procedure.

c. Testing for Heavy-Duty Highway Vehicles

The regulations at 40 CFR part 86, subpart M, describe how to test heavy-duty

vehicles above 14,000 lbs GVWR to demonstrate compliance with evaporative emission 

standards. Most of these provisions are identical to those that apply under 40 CFR part 

86, subpart B. As described in Section IV.C, we are eliminating subpart M and replacing 

it with a simple instruction to test these heavy-duty vehicles using the procedures of 

subpart B, with a small number of appropriate modifications noted as exceptions to the 

light-duty test procedures. 

d. Service Information Requirements for Light-Duty Vehicles

The service information regulations were originally adopted for light-duty motor 

vehicles 40 CFR 86.038-96. These requirements applied for 1996 and later model year 

vehicles. Starting with the 2001 model year, these same requirements were copied into 

§86.1808-01. These two sets of requirements are identical except for the model year 

applicability and a variety of very minor stylistic differences. We are revising the service 

information regulations in §86.1808-01 to apply also to 1996 through 2000 model year 

vehicles, and to correct several typographical and formatting errors. These changes 

should have no practical significance, since the requirements are the same in both 

regulatory sections.

3. Motorcycle Driving Schedules

The CFR includes two separate driving schedules for motorcycles. The first, for 

motorcycles at or above 170 cubic centimeters (cc), is identical to that used for light-duty 

vehicles except that the speeds are converted to kilometers per hour. The second driving 

schedule, for smaller motorcycles, is also identical except for a period of about three 

minutes of reduced-speed operation. To simplify this arrangement, and to better 

incorporate the new LA-92 driving schedule described in Section IV.B for heavy-duty 

vehicles, we are eliminating the identical portions of these drive schedules. This revised 

approach involves referencing the driving schedule for light-duty vehicles with 

instructions to convert to kilometers per hour and round the resulting speeds to the 

nearest 0.1 kilometers per hour, instead of repeating the driving schedule just to publish 

the same speed trace in different units. The unique portion of the driving schedule is laid 

out, with reference to the light-duty driving schedule for the portions that are unchanged. 

This is not intended to cause any change in the current requirements or practices for 

certifying motorcycles.
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4. Updating Reference Procedures

The regulations in 40 CFR part 1065 depend on a large number of reference 

procedures and technical standards from ASTM, SAE International, and ISO, among 

others. These reference procedures and technical standards are updated periodically to 

keep them current with ongoing developments in the field. Many times these changes 

include only minor corrections or clarifications. In other cases the updates incorporate 

new test methods, accommodate changing engine technologies, or other more substantive 

changes. Whether the updated reference documents involve major changes or not, it is 

important for the regulations to rely on documents that are readily available. Toward that 

end, we are updating §1065.1010 with the latest versions of all the reference procedures 

and technical standards that we were able to identify. 

In areas of the regulations other than part 1065, we are generally updating the 

regulation to rely on the latest reference documents where we are changing or adding a 

provision that depends on one of these reference documents, but we are not making broad 

or universal changes to these references in other parts of the regulation.

One particular area of interest relates to rounding. As described in Section 

IV.H.3, we are defining “round” for 40 CFR part 86 to have the meaning we give in 40 

CFR 1065.20, which spells out a detailed rounding protocol that is consistent with ASTM 

E29 and NIST SP811. This definition of “round” will defer to existing references in part 

86 so that the part 1065 protocol will apply only where we do not specifically refer to 

ASTM E29. This is not intended to change the policy for calculating or reporting 

numerical quantities, but rather to clarify the protocol and avoid the administrative 

complication of referencing multiple versions of the ASTM document. We expect to 

eventually remove all mandatory references to ASTM E29 and NIST SP811 and rely 

exclusively on §1065.20 as the method for rounding numerical quantities.

VII. What are the Cost Impacts of the Rule?

We have estimated the costs for both the vehicle standards described in Section 

IV and the fuel standards described in Section V. This section summarizes these costs, 

while further information on the methodology we used to develop these costs can be 

found in Chapters 2 and 5 of the RIA.

Section VII.C provides a summary of total costs for the final vehicle and fuel 

programs together. For a comparison of the program costs to the monetized health and 

welfare benefits, see Section VIII.

A. Estimated Costs of the Vehicle Standards

To determine the cost for vehicles, we first determined which technologies were 

most likely to be applied by vehicle manufacturers to meet the standards. These 

technologies were then combined into technology packages which reflected vehicle 
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design attributes that directly contribute to a vehicle’s emissions performance. The 

attributes considered included vehicle type (car or truck), number of cylinders, engine 

displacement, and the type of fuel used (gasoline or diesel). We also created separate 

packages for light-duty and heavy-duty trucks and vans. In estimating both cost and 

technology application, we have relied on publicly available information (such as that 

developed by California or submitted as comments on the proposal), confidential 

information supplied by individual manufacturers and suppliers, and the results of our 

own in-house testing. The technology packages that we developed represent what we 

consider to be the most likely average emissions control solution for each vehicle type.

In general, we expect that the majority of vehicles will be able to comply with the 

Tier 3 standards which we are adopting through refinements of current emissions control 

components and systems. Some vehicles may require additional emission controls, such 

as large trucks with large displacement engines (in particular, LDT3s and LDT4s). 

Overall, smaller, lighter-weight vehicles will require less extensive improvements than 

larger vehicles and trucks. Specifically, we anticipate a combination of technology

upgrades including:

 Catalyst Platinum Group Metal (PGM) Loading. Increased catalyst 

application of precious metals.

 Optimized Close-coupled Catalyst: Improvements to the catalyst system 

design, structure, and packaging to reduce light-off time.

 Optimized Thermal Management: Overall thermal management of the 

emissions control system to shorten the time it takes for the catalyst to lightoff.

 Secondary Air Injection: Increased application of secondary air injection for 

some 6-cylinder and larger engines.

 Engine Calibration: Engine control and calibration modifications to improve 

air and fuel mixtures, particularly at cold start and/or to control secondary air 

and hydrocarbon adsorbers.

 Hydrocarbon Adsorber: Limited application of hydrocarbon adsorbers to trap 

hydrocarbons during cold start and release the hydrocarbons after the catalyst 

lights off.

 Evaporative Emissions Controls: Improved evaporative emissions systems, 

including canister scrubbers, more permeation-resistant materials, and 

improved system integration.
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1. What Changes Have Been Made to Vehicle Program Costs Since Proposal?

Chapter 2 of the final RIA contains details about what changes have been made 

since the proposal and why we have made those changes. We have made several changes 

since the proposal, but two changes have significant impacts on the final rule vehicle 

costs and help to explain the large reduction in cost estimates between proposal and final 

rule. The first of these significant changes involves the catalyst platinum group metal 

(PGM) loading costs. As commenters pointed out, the cost estimates in the proposal have 

become dated, as they were based largely on four-year-old estimates of the CARB 

LEVIII program. For this final rule, we have developed a more robust catalyst loading 

cost estimate using a methodology suggested by one commenter.532 This more robust 

estimate results in lower costs than estimated in the proposal.

The second significant contributer to reduced final rule cost estimates is the use of 

the MY 2017-2025 fleet mix projected to result from the most recent GHG and fuel 

economy rules. That projected fleet mix shows a large percentage of four-cylinder 

engines (generally these are inline engines, or I4), which are less costly to modify to 

achieve Tier 3 compliance than the proposal’s projected MY 2012-2016 fleet mix, which 

included many more V-configuration six-cylinder (V6) and eight-cylinder (V8) engines. 

We mentioned in the preamble to the proposal our intention to use the projected MY 

2017-2025 fleet for our final rule cost analysis (see 78 FR 29970).

We have made many other updates to the analysis for this final rule. For 

example, we reviewed the MY2013 certification database to evaluate the certified 

emission levels of the fleet. We found that many vehicles are already being certified with 

emission levels that would meet final Tier 3 standards. Further, many vehicles have 

certified emission levels that are 70% of the 0.30 g/mi NOx+NMOG standard, meaning 

that sufficient compliance margin exists for those vehicles to comply with Tier 3 without 

any additional costs.533 Our final rule estimates no exhaust emission-related Tier 3 costs 

for these vehicles (evaporative emission-related costs are discussed below).

We have also concluded that active HC adsorbers are not expected on any

vehicles and, instead, a passive HC adsorber will be used. The passive HC adsorber is 

considerably less costly. We base this on comments from MECA and ICCT and on 

confidential business information (CBI) provided by Tier 1 suppliers after the 

proposal.534 We have also decreased our evaporative emission control costs, in part 

 

532 ICCT Comments in Response to the Tier 3 Proposed Rulemaking, Docket ID No. EPA-HQ-OAR-2011-

0135-4304; Posada, Francisco, et. al., “Estimated Cost of Emission Control Technologies for Light-Duty 

Vehicles Part 1 – Gasoline,” SAE 2013-01-0534, 4/8/2013.

533 As discussed in Section IV, we expect manufacturers to target 60-80% of the standard, or 20-40% 

compliance margins under Tier 3.

534 See ICCT, Docket ID No. EPA-HQ-OAR-2011-0135-4304, at page 11 of 21; see MECA, Docket ID 

No. EPA-HQ-OAR-2011-0135-4675, at page 3 of 7.
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because of the high penetration of gasoline engines with direct injection as projected by 

the MY 2017-2025 GHG and fuel economy rules. Direct injection removes a large 

source of evaporative emissions and, thus, means fewer vehicles need to add certain 

evaporative control technologies. We have also decreased the penetration rates of 

secondary air injection in the later years of the program, for reasons described below. 

Lastly, we have modified very slightly our indirect cost markups to account for the fact 

that most of the research and development efforts required of auto makers are in response 

to CARB’s LEVIII rule and need not be conducted again for Tier 3 compliance.

We have made some changes that have increased costs, although the cost 

increases are smaller in magnitude than the cost decreases from other changes so, on net, 

estimated vehicle-level costs are lower than in the proposal. One such change was to 

increase the engine calibration costs (from roughly $2/vehicle to $5/vehicle), to cover 

expected calibration efforts associated with PM control on direct injected gasoline 

engines. We have also increased the penetration rates of the technology we term 

“optimized thermal management” for some vehicle classes. This was done to ensure that 

all vehicles adding technology include costs for either optimized close-coupled catalysts 

or optimized thermal management by setting the combined phase-in rate in each vehicle 

category to 100%. Another change was to update all costs from 2010 dollars to 2011 

dollars.535 

With respect to total program costs, the significant change since proposal was to 

exclude costs incurred on vehicles sold in all states (California and elsewhere) that have 

adopted the California LEVIII program. As a result, our estimated costs per vehicle are 

applied to millions fewer vehicles in the final rule, thus making the total program costs 

considerably lower. And finally, we have included operating savings (fuel savings) 

associated with avoiding the loss of fuel that would have otherwise evaporated absent the 

new Tier 3 controls. The otherwise evaporated fuel is ultimately used to propel the 

vehicle, thus providing a savings to the consumer.

2. Summary of Vehicle Program Costs

As in the proposal, we have developed our costs with respect to a given vehicle 

type and the type of engine with which it is equipped. The final cost per vehicle is the 

result of not only the cost per technology, but also the application rate of that technology

for each vehicle type. For example, while the $119 (2017 cost in 2011$) cost of 

secondary air injection is the same for both a 6-cylinder (V6) and 8-cylinder (V8) 

application, we anticipate that only 25 percent of the V6 and 75 percent of the V8 

 

535 We have updated 2010 dollars to 2011 dollars using the Gross Domestic Product (GDP) price deflator as 

reported by the Bureau of Economic Analysis on May 30, 2013. The factor used, taken from Line 1 of 

Table 1.1.4 Price Indexes for Gross Domestic Product, was 1.035 to convert from 2009$ and 1.021 to 

convert from 2010$. For example, to convert from 2010$ to 2011$, we calculated the (value in 

2010$)x1.021=(value in 2011$).
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passenger car applications will require it in MY2017. In the same way, we anticipate that 

light truck applications will not add that technology until MY2018, again at a 25%/75% 

penetration rate for V6/V8 applications, respectively. Table VII-1 below shows our 

estimate of the cost of each of the emission control technologies for the gasoline vehicles 

affected by this final rule. Table VII-2 provides the anticipated application rate of the 

technology by vehicle type. Note that all of the costs shown in this section are in 2011 

dollars and are marked-up by an Indirect Cost Multiplier (ICM) so they include both 

direct and indirect costs. (For details of regarding ICMs and their application refer to 

Chapter 2 of the RIA.)

Table VII-1 MY2017 Technology Costs by Gasoline Engine Type (2011$)a

Technology PC I4

PC 

V6 PC V8 LT I4

LT 

V6

LT 

V8

HDc

Class 

2b

HD 

Class 

3

>14K 

HD d

Catalyst 

Loading $43 $68 $101 $50 $75 $108 $59 $59 N/R

Optimized 

Closecoupled 

Catalyst

$24 $48 $71 $24 $48 $71 N/R N/R N/R

Optimized 

Thermal 

Management

$36 $36 $36 $36 $36 $36 $36 $36 N/R

Secondary

Air Injection N/Rb

$119 $119 N/R $119 $119 N/R N/R N/R

Engine 

Calibration $5 $5 $5 $5 $5 $5 $5 $5 N/R

Hydrocarbon 

Adsorber N/R N/R $20 N/R N/R $20 N/R N/R N/R

Evaporative 

Emissions 

Controls

$15 $15 $15 $14 $14 $14 $11 $17 $17

a

PC=passenger car; LT=light truck; I4=In-line 4-cylinder; V6= 6-cylinder, V8= 8-cylinder

b N/R – Not Required

c Heavy-duty

d Gasoline only
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Table VII-2 Technology Application Rates for Gasoline Vehicles

Technology PC I4 a PC V6 a PC V8 

a LT I4 b LT V6 b

LT V8 

b

Class 

2b & 3 

b

>14K 

HD c

Catalyst 

Loading 100% 100% 100% 100% 100% 100% 100% 0%

Optimized 

Closecoupled 

Catalyst

50% 60% 75% 50% 60% 75% 0% 0%

Optimized 

Thermal 

Management

50% 40% 25% 50% 40% 25% 25% 0%

Secondary

Air Injection 

d

0% 25% 75% 0% 25% 75% 0% 0%

Engine 

Calibration 100% 100% 100% 100% 100% 100% 100% 0%

Hydrocarbon 

Adsorber 0% 0% 15% 0% 0% 15% 0% 0%

Evaporative 

Emissions 

Controls

100% 100% 100% 100% 100% 100% 100% 100%

a MY2017 and later

b MY2018 and later (Note that, for the vehicle cost analysis, LDT1/2/3/4 are treated 

collectively as light trucks.)

c Gasoline only

d

Secondary air injection penetration rates ramp down from values shown here as follows: 

Passenger car and light truck V6 gasoline: 25/25/25/15/15/5/5/5/5% beginning in 2017

except for light trucks which have a 0% penetration in MY2017; Passenger car and light 

truck V8: 75/75/75/65/65/55/55/45/45% beginning in 2017 except for light trucks which 

have a 0% penetration in MY2017.

Note the footnote to Table VII-2 describing the penetration rates used for 

secondary air injection systems in V6 and V8 gasoline vehicles. In the proposal, we did 

not use a ramped down penetration rate like that being used in this final rule for this 

technology. We have revised the penetration rates in this final rule because of the 

historical pattern by which secondary air injection has been implemented in the light-duty 

fleet. Generally, secondary air makes an appearance in the early implementation stages

and then is slowly phased out as auto makers learn more about and become more 

comfortable with their ability to meet any new emission standards with a lower degree of 

reliance on secondary air. Presumably, this technology is added in the early stages 

because it provides effective and relatively easily implemented cold temperature control 

for difficult applications in which auto makers tend to consider every technique at their 

disposal to ensure full useful life compliance. Then, as experience is gained, the 
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secondary air injection systems slowly disappear from the new light-duty fleet due to its 

relatively high cost. We expect a similar implementation pattern in response to Tier 3. 

This position is corroborated by ICCT in their comments where they say, in the context 

of LEV II vehicles meeting the LEV III standards, “In some cases it was easier and 

cheaper for manufacturers to add existing hardware (i.e., secondary air injection) than to 

invest the engineering resources to fully optimize precise air/fuel control and fast lightoff strategies, or to develop new hardware” (emphasis added).536

 

Medium Duty Passenger Vehicles (MDPVs) were included in the light-duty fleet 

as part of Tier 2. Given their current certification requirements for criteria pollutants, we 

have included the costs for MDPVs to meet the Tier 3 standards with the light truck cost 

estimates. We do not expect that the technologies required to meet the Tier 3 standards 

for MDPVs will be different from those applied to light trucks (with V8 engines), as in 

many cases there are identical powertrains and chassis between the large light truck and 

MDPV platforms.

We also expect that some manufacturers may continue to build and sell light-duty

diesel vehicles and certify those vehicles to Tier 3. All light-duty diesel vehicles 

currently being sold in the federal fleet are equipped with some means of controlling 

NOX emissions, either a Lean NOX Trap (LNT) or selective catalytic reduction (SCR) 

system. As these systems are already very effective in controlling NOX emissions, we 

expect that they will remain the primary emissions control systems to meet Tier 3. 

Similar to gasoline engines, diesel powertrains may be required to improve the 

effectiveness of their emission control systems during cold start. Therefore, we have 

developed our costs for diesels with the expectation that the incremental costs will be 

realized to improve LNT and SCR systems during cold start. The improvements have 

been categorized as general SCR optimization, which include packaging changes to the 

SCR system to allow faster light off; optimized thermal management, to reduce the 

thermal mass of the system and allow more of the combustion heat to reach the SCR 

system sooner; and the calibration work associated with both of these changes. Table 

VII-3 below describes both the cost of the technologies as well as their anticipated 

application rates.

 

536 See EPA-HQ-OAR-2011-0135-4304 at page 11 of 21.
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Table VII-3 MY2017 Technology Costs and Application Rates for Diesel Engines 

(2011$)

Technology

Diesel Engine 

Costs

(all types)

Light-duty and 

Heavy-duty 

Application 

Rate

Optimized Thermal Management $36 25%

Engine Calibration a$2 100%

SCR Optimization $59 100%

a These engine calibration costs are the same as the proposal since the increased 

calibration costs associated with gasoline direct injection do not apply for diesels.

We also estimated costs for HDVs between 8,501 and 14,000 lbs GVWR and for 

gasoline HDVs above 14,000 lbs. Vehicles in this range are often referred to as Class 2b 

(8,5001-10,000 lbs), Class 3 (10,001-14,000 lbs) and Class 4 and above (>14,000 lbs) 

vehicles and are typically full-size pickup truck and work vans. We applied the same 

process to the heavy-duty vehicles as we did to the light-duty vehicles. Heavy-duty costs 

and application rates are included in Table VII-1, Table VII-2, and Table VII-3 above. 

We have also considered the impacts of manufacturer “learning-by-doing” on the 

technology cost estimates. We reflect the phenomenon of volume-based learning curve 

cost reductions in our modeling using two algorithms, depending on where in the learning 

cycle (i.e., on what portion of the learning curve) we consider a technology to be: the 

“steep” portion of the curve for newer technologies and “flat” portion of the curve for 

more mature technologies. We have made no changes to the application of learning 

curve cost reductions relative to the proposal. For details surrounding learning-by-doing, 

please refer to Chapter 2 of the final RIA. 

The evaporative emissions standards that we are adopting will impose relatively

small cost impacts. We estimate the cost of system improvements, including indirect 

costs, to be less than $17 (MY2017 cost in 2011$) per vehicle, for all vehicle classes. 

This incremental cost reflects the cost of moving to low-permeability materials, reduced 

number of fuel-system connections, longer contiguous lengths of plumbing, and lowpermeation connectors. We believe that learning is also appropriate for evaporative 

emissions control systems as described above and in more detail in Chapter 2 of the RIA. 

We have used the individual technology costs discussed briefly here and in more 

detail in Chapter 2 of the RIA to estimate package costs for each of the different gasoline 

and diesel engine types in the fleet (i.e., I4 passenger car, V6 passenger car, etc.). We 

have then multiplied these package costs by the projected sales estimates for the years 

2017 and later. The projected sales estimates used, as noted earlier, represent the future 

fleet mix rather than today’s fleet mix. That fleet mix is discussed in more detail in 

Chapter 2 of the RIA. With these total annual costs, we then determined the salesweighted average cost increase for all passenger cars, light trucks and heavy-duty 

vehicles. Table VII-4 below provides our estimates of the incremental cost per vehicle 
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by model year for both tailpipe and evaporative emissions standards. These values reflect 

the total direct and indirect manufacturing costs as well as the appropriate learning-bydoing effects. As stated above, a large portion of the cost is incurred in the initial model 

years. Costs then continue to rise as the percentage of vehicles complying with the final 

standards increases through MY 2025. 

We have estimated costs consistent with the fact that manufacturers would be 

required to start the phase-in of Tier 3 standards in MY2017 for vehicles under 6,000 lbs 

GVWR and the expectation that MY2018 will begin the phase-in for vehicles greater 

than 6,000 lbs GVWR. Based on the declining fleet averages for cars and trucks, we 

have apportioned our estimates for full compliance across the phase-in years as a 

percentage of the final standard. Manufacturers will be required to move from a Tier 2 

Bin 5 fleet average in MY2017 (for vehicles <6,000 lbs GVW). This results in a 

significant step in stringency. As a result, a large portion of the costs are expected to be 

incurred in the initial model years. Finally, manufacturers have the opportunity in 

MY2015 and MY2016 to earn Tier 3 credits by producing a fleet that is cleaner than the 

current Tier 2 requirements. While we expect that most manufacturers will earn credits, 

either by selling California vehicles as 50-state vehicles or by certifying existing vehicles 

to lower Tier 2 bins, we have not reflected these credits in our cost analysis. In that way, 

we believe that our cost estimates are conservative.

Table VII-4 Per Vehicle Technology Costs by Model Year (2011$) a

Model Year 2017 2018 2019 2020 2021 2022 2023 2024 2025

Passenger car $46 $51 $53 $57 $59 $63 $63 $64 $65

Light truck $0 $73 $78 $82 $86 $88 $87 $87 $86

Light-duty Combined $29 $59 $62 $66 $68 $72 $71 $72 $72

Class 2b $0 $44 $51 $60 $66 $75 $71 $70 $69

Class 3 $0 $33 $41 $49 $57 $65 $62 $61 $60

>14,000 pound HD $0 $10 $10 $13 $13 $16 $15 $15 $15

a Costs shown include costs for the Tier 3 standards on vehicles sold outside California and other states that 

have adopted LEVIII.
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Total annual costs are shown below in Table VII-5. This table includes all costs 

associated with the final Tier 3 vehicle standards, i.e., both exhaust and evaporative 

emission standards. Also included are facility-related costs associated with the final 

requirements to conduct more PM testing on gasoline vehicles. (Additional detail 

regarding the PM facility costs are described in section 2.6 of the final RIA.) We show 

the facility costs in the year 2016 even though the program does not begin until 2017. 

These costs represent the construction costs that would be incurred before the first year of 

the standards in preparation for the testing efforts that would be required. We have not 

made any changes to the costs per facility upgrade relative to the proposal, and we 

present the details supporting our estimates in Chapter 2 of the final RIA.

Lastly, as noted above, we have included the impact on operating costs associated 

with the new evaporative emission controls. Because the evaporative emissions that 

would have been emitted absent the new standards will ultimately be used to propel the 

vehicle, the avoided evaporative emissions represent a savings to the consumer. While 

these savings are small on a per-vehicle basis—generally less than $2/vehicle over its 

lifetime—they are notable on a fleetwide basis where, in calendar year 2025, they result 

in $11 million in pre-tax savings. We also considered other operating costs, such as 

maintenance costs and repair costs, but concluded that the nature of the Tier 3 

compliance technologies will not result in any increases or decreases in existing operating 

costs. We present the details about these operating savings in Chapter 2 of the final RIA.

Table VII-5 Annual Costs of the Tier 3 Vehicle Program (Millions of 2011 Dollars)a

Year

Exhaust Evap Operating b

Facilities Total LD HD All LD HD All LD HD All

2016 $0 $0 $0 $0 $0 $0 $0 $0 $0 $21.4 $21.4

2017 $268 $0 $268 $25.5 $0 $25.5 $0 $0 $0 $3.52 $297

2018 $519 $20.2 $539 $70.2 $3.24 $73.4 -$1.17 -$0.047 -$1.22 $3.52 $615

2019 $555 $24.2 $579 $69.2 $3.18 $72.4 -$2.03 -$0.094 -$2.12 $3.52 $653

2020 $571 $27.8 $599 $94.3 $4.12 $98.4 -$3.22 -$0.160 -$3.38 $3.52 $697

2021 $598 $31.5 $630 $92.8 $4.04 $96.8 -$4.44 -$0.226 -$4.67 $3.52 $725

2022 $605 $34.8 $640 $116 $4.93 $121 -$5.96 -$0.309 -$6.27 $3.52 $758

2023 $606 $33.3 $639 $111 $4.73 $116 -$7.45 -$0.390 -$7.84 $3.52 $751

2024 $620 $33.1 $653 $109 $4.70 $114 -$8.95 -$0.472 -$9.42 $3.52 $761

2025 $635 $32.8 $668 $108 $4.66 $113 -$10.4 -$0.553 -$11.0 $3.52 $773

2030 $632 $31.8 $664 $108 $4.56 $113 -$18.0 -$0.959 -$19.0 $3.52 $761

a Costs shown include costs for the Tier 3 standards on vehicles sold outside California and other states that 

have adopted LEVIII.

b Operating costs use pre-tax fuel prices; negative cost values denote savings.
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B. Estimated Costs of the Fuel Program

The sulfur control program we are adopting is expected to result in many refiners 

further investing in sulfur control hardware and changing the operations in their refineries 

to reduce their gasoline sulfur levels. The final sulfur control program requires refiners 

and importers to reduce their gasoline sulfur levels on average down to 10 ppm. The 

ABT provisions being adopted along with the 10 ppm average sulfur control standard 

will allow refiners that reduce their gasoline sulfur levels below 10 ppm to earn credits 

and trade those credits to other refiners who would find it more expensive to reduce their 

sulfur levels down to the average standard. The ABT program will allow refiners to 

optimize their investments, which we believe will result in achieving the average sulfur 

control standard nationwide at lower costs. We are maintaining the current 80 ppm sulfur 

cap at the refinery gate. We estimate that the national average refinery costs incurred to 

comply with the fully phased-in Tier 3 sulfur control program with ABT program will be 

0.65 cents per gallon, averaged over all gasoline. This estimate includes the capital costs, 

which are amortized over the volume of gasoline produced. 

In this section we summarize the methodology used to estimate the costs of Tier 3 

sulfur control and our estimated costs for the program. A detailed discussion of all of 

these analyses is found in Chapter 5 of the RIA. 

1. Overview 

The basic methodology we used to estimate the cost of sulfur control for the final 

rule is similar to that for other rulemakings. Using a refinery-by-refinery cost model that 

we developed for this rulemaking, we projected the sulfur control technology expected to 

be used by each refinery, and the cost of each refinery’s sulfur control step, to estimate 

compliance with the final sulfur control program. We aggregated the individual refinery

costs to develop a national average cost estimate for the final sulfur control program. We 

modeled costs assuming an in-use average of 10 ppm and assuming refiners take full 

advantage of the ABT provisions and minimize overcompliance based on experience for 

the Tier 2 program demonstrating this today. 

Refinery-by-refinery cost models are useful when individual refineries are 

expected to respond to program requirements in different ways and/or have significantly 

different process capabilities. Furthermore, as is the case with sulfur control, such 

approaches are possible when the refinery changes required are primarily “add-ons” that 

do not impact the fundamental operation at the refinery. Thus, in the case of modeling 

potential gasoline sulfur control programs, we needed a model that could accurately

simulate the variety of decisions refiners will make at different refineries, especially in 

the context of a nationwide ABT program. For this and other related reasons, we 

developed a refinery-by-refinery cost model to evaluate the costs and other impacts of the 

final sulfur control program. 
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Refinery-by-refinery cost models have been used in the past by both EPA and the 

oil industry for such programs as the Mobile Source Air Toxics gasoline benzene 

control537, highway and nonroad diesel fuel sulfur standards. They are a proven means for 

estimating the cost of compliance for fuel control programs. While they will never 

precisely model and predict individual refinery operations and impacts, they provide both 

a good assessment of the overall market impacts and of the variation of impacts across 

the refineries. Refinery-by-refinery models are also very useful when estimating the cost 

impacts of ABT programs.

We used a linear program (LP) cost model to estimate a cost for recovering the 

octane lost when refiners further desulfurize their gasoline to comply with the 10 ppm 

sulfur standard. Our refinery modeling run for estimating octane cost assumed E10 with 

a small amount of E85. This cost is a key input into the refinery-by-refinery cost model. 

The octane cost we developed from the LP model is $0.31 octane number-barrel. We also 

used the LP refinery model to estimate the change in gasoline qualities that occurs when 

refiners make up for the lost octane that were used as inputs into the emissions impacts 

analysis discussed in Section III.

2. Methodology 

The way that the refinery-by-refinery cost model works can be subdivided into 

two primary steps. First, the model attempts to model how refiners blend up gasoline at 

each of their refineries. This is an important step because the fluidized catalytic cracker 

(FCC) naphtha, a product from FCC units, is responsible for almost all the sulfur in 

gasoline, even after complying with Tier 2. To help our understanding of how refiners 

blend up their gasoline, we used refinery unit throughput data which tell us how refiners 

are using their refinery units. The per-gallon cost is calculated over all the gasoline pool, 

while the desulfurization cost is incurred by desulfurizing FCC naphtha; thus, the relative 

volume of FCC naphtha to the rest of the gasoline pool is important. 

The second primary step of the refinery-by-refinery cost model is to project how 

refiners would comply with the Tier 3 10 ppm average sulfur standard taking into 

consideration how they complied with the 30 ppm Tier 2 gasoline sulfur standard. To 

determine how refiners would comply with Tier 3, we contacted the vendors which 

provided the technology to refiners for complying with Tier 2 and continued to provide 

onsite support. Vendors provided information to us for installing grassroots units or 

revamping existing FCC postreaters sufficient to reduce the gasoline pool down to 10 and 

5 ppm. We also evaluated the need and cost to refiners to reduce the sulfur levels of 

other refinery streams and included costs for those refineries to hydrotreat the light 

straight run naphtha stream where such additional control appeared warranted. Finally, 

we assessed the cost for complying with Tier 3 assuming that refiners take advantage of 

 

537 “Control of Hazardous Air Pollutants From Mobile Sources,” 72 FR 8428, February 26, 2007.
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an ABT program. To assess the costs for the Tier 3 program that included an ABT 

program, we organized the estimated sulfur reduction costs for each refinery for 

achieving both 5 and 10 ppm from lowest to highest to determine the set of investments 

for Tier 3 which minimized the cost of the Tier 3 program.

We made a number of modifications to the refinery-by-refinery model for the 

final rule cost analysis. Based on a review of credit trading occurring for Tier 2, which 

revealed that credits are freely traded between refining companies, we changed our cost 

analysis to assume nationwide credit trading instead of restricting it to intra-company 

trading, as we did for the Tier 3 proposal’s cost analysis. We incorporated refinery unit 

throughput data that we obtained from EPA’s Office of Air Quality Planning and 

Standards (OAQPS). The refinery model we used for this final rule estimated sulfur 

reduction cost for each refinery based on actual starting sulfur levels, instead of assuming 

that each refinery was desulfurizing their gasoline from 30 ppm to 10 or 5 ppm. We 

further refined our assessment for treating light straight run naphtha, but did not include 

any costs for treating butane since we found out from a vendor that butane is routinely

treated today. We requested and received additional desulfurization cost data from 

vendor companies that we applied in our cost analysis. In response to comments from 

peer reviewers and other information that we obtained, we applied a higher offsite factor 

and a higher contingency factor to the capital costs. Additional changes that were made 

for the final rule cost analysis are discussed in Chapter 5 of the RIA. 

Our refinery-by-refinery sulfur cost model incorporates data on throughput 

volumes for each of the major refinery units in each refinery, including the crude unit, 

FCC unit, coker, hydrocracker, alkylation unit, reformer, isomerization unit, naphtha 

hydrotreater and aromatics plant. Unlike the unit capacity data used for the NPRM 

analysis, throughput volumes are a much more robust set of data because they eliminate 

the need to try to estimate how that refinery is operating that unit, or whether the unit is 

shutdown. We also used purchase and sales information for each refinery such as 

purchases of natural gas liquids, naphtha and sales of propylene. The propylene sales

data were used to estimate whether a refinery is operating its FCC unit in propylene 

maximization mode. If a refinery is operating in propylene maximization mode, some of 

the volume of FCC naphtha is cracked to produce increased volume of propylene for 

sales to the chemicals industry, but these refineries are producing a smaller volume of 

FCC naphtha. While the increased use of refinery-specific data has improved the ability

of the refinery-by-refinery model to represent the operations of each refinery, there still is 

uncertainty about how each refinery is being operated. 

To assess how well our refinery model estimates the gasoline production for each 

refinery, we compared the gasoline production volume estimated by the refinery-byrefinery model for each individual refinery to the 2011 gasoline volumes reported by 

refiners to EPA. Despite the use of very robust throughput data, there was still an 

overproduction of gasoline by quite a few refineries. In trying to address this 

overproduction of gasoline volume by our refinery model, we spoke to refiners, vendors 

and peer reviewers and also reviewed the results of our LP refinery modeling runs. This 
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led us to conclude that this volumetric difference in the refinery model was due in many

cases to not accounting for the undercutting of heavy gasoline into the jet and diesel fuel 

pools. We further discuss the implications of undercutting in Section VII.B.3. Overall, 

after we made some adjustments by assuming that certain refiners are undercutting heavy 

gasoline to distillate, we were satisfied with the model’s volumetric estimates. To set up 

the refinery model, the model was updated with a projection of refined product volumes, 

and of input and output prices, from the Energy Information Administration’s Annual 

Energy Outlook (AEO) 2013 for the year 2018. 

For this refinery-by-refinery sulfur cost model, we conducted two sets of 

independent peer reviews. One set of peer reviews was conducted for the version of the 

refinery-by-refinery model we developed for estimating the costs for the NPRM. We 

reviewed the peer review comments and decided that the impact on the estimated costs 

would be small, so we deferred making changes to address those peer review comments 

until the final rule. We developed another version of the refinery-by-refinery cost model 

which addressed the comments we received from the first set of peer reviews, as well as 

included additional improvements to the refinery model based on new information that 

we received after we conducted the cost analysis for the NPRM. We submitted the final 

rule version of the refinery cost model for a second round of peer review. The peer 

review comments as well as our responses to these comments are contained in the docket. 

We addressed many of the comments made by the peer reviewers in the final version of 

the cost model. The oil industry has also conducted a similar analysis using a refineryby-refinery cost model, and we discuss the results of its analysis at the end of this 

chapter. 

Our assessment of how refiners will comply with Tier 3 has not changed since we 

conducted our cost analysis for the NPRM. The refinery unit responsible for the greatest 

contribution of sulfur to gasoline is the FCC. The FCC processes a very heavy feedstock 

which contains high levels of sulfur.538 When the FCC cracks this heavy, sour feedstock, 

a portion of the sulfur in the feed to the FCC ends up in the FCC naphtha, an important 

gasoline blendstock stream.539 Before the Tier 2 sulfur control program was 

implemented, FCC naphtha contributed over 95 percent of the sulfur to a refinery’s 

gasoline, and now that Tier 2 has been fully implemented it still contributes roughly 80 to 

90 percent of the sulfur in refiner’s gasoline for those refineries with FCC units. To 

comply with the Tier 2 sulfur control program, most refiners installed FCC naphtha 

hydrotreaters (FCC postreaters) and some refiners installed FCC feed hydrotreaters (FCC 

pretreater) to reduce that unit’s sulfur contribution to their gasoline pool. The 

technologies installed include Axens Prime G+, Exxon-Mobil Scanfining, CDTech’s 

CDHydro and CDHDS, Sinopec’s S-Zorb and UOP’s ISAL (UOP now offers a 

postreating technology named Selectfining). Despite the much lower sulfur contribution 

 

538 A hydrocarbon stream which contains large amounts of sulfur is also referred to as being sour. In 

general, the heavier the hydrocarbon portion of crude oil, the higher the natural sulfur content.

539 On average, the fluidized catalytic cracker supplies about 35 percent of a refiner’s gasoline output.
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to the gasoline pool by the FCC after complying with Tier 2, the vendors which supplied 

sulfur control technology for complying with the Tier 2 sulfur control program have 

informed us that to comply with a more stringent sulfur standard, refiners are expected to 

further reduce the sulfur in the FCC naphtha. We contacted each of those technology

vendors, and some of them provided information useful to estimate the cost of lowering 

the sulfur in the FCC naphtha to allow each refinery to reduce the sulfur in its gasoline to 

10 ppm. We also reviewed literature that is available on the Web to further understand 

what would be involved to achieve a 10 ppm sulfur standard using postreating (see 

Chapter 4 of the RIA). We were able to obtain some additional sulfur cost information 

from the vendors since we conducted our cost analysis for the proposed rule, and this was 

incorporated into our cost analysis.

Gasoline desulfurization vendors were pessimistic that the operations of FCC 

pretreaters could be adjusted to enable those refineries which relied on those units to 

comply with the Tier 2 sulfur standard to meet a 10 ppm sulfur standard. Many of those 

FCC pretreater units have marginal (less than two years) turnaround times today and they

would either require a major revamp or suffer even shorter turnaround times if they were 

to simply be turned up. For the refineries solely relying on FCC pretreaters to comply 

with Tier 2, desulfurization vendors project that most refineries in this situation will put 

in grassroots FCC postreaters to allow those refineries to comply with a 10 ppm gasoline 

sulfur standard. However, since adding grassroots FCC postreaters is relatively

expensive for the amount of sulfur reduction obtained, the ABT analysis we conducted 

avoided many of these types of investments. Instead, the refiners with refineries in this 

situation are projected to acquire credits from refiners capable of reducing sulfur levels 

below 10 ppm at a lower cost.

In addition to addressing the sulfur in the FCC naphtha, we believe that some 

refineries may need to reduce the sulfur in the light straight run (LSR) naphtha. Most 

refiners hydrotreat the LSR before sending that stream to an isomerization unit, and 

therefore that stream is very low in sulfur. Other refiners use a sweet crude oil, and once 

the LSR is treated by using an extraction desulfurization technology, the sulfur level of 

the LSR is likely to be very low (under 10 ppm). However, some refineries that refine a 

more sour crude oil slate and do not have isomerization units could have fairly high 

sulfur levels in their LSR, even after using extraction desulfurization. For these 

refineries, we conducted an assessment to determine whether these refineries have 

sufficient hydrotreating capacity to hydrotreat the LSR. We believe that refiners that do 

not currently desulfurize their LSR, but may need to do so because their crude oil is not 

sweet, could do so by either feeding it to their naphtha hydrotreater (the hydrotreater 

which desulfurizes the feed to the isomerization and reformer units), or perhaps even to 

the FCC postreater; we added a cost for this. Because LSR does not contain any olefins, 

it is an easy stream to hydrotreat and actually improves the hydrotreating conditions 

within the FCC naphtha hydrotreater. 
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3. Fuel Program Costs 

We used the refinery-by-refinery cost model to estimate the costs of the 10 ppm 

average standard being adopted in this final rule. The Tier 3 fuels program maintains the 

80 ppm cap sulfur control standard that was put in place under the Tier 2 sulfur program. 

In general, the cost model indicates that further desulfurizing the FCC naphtha will be the 

most cost-effective means for achieving sulfur control. We accounted for additional 

costs to refiners for desulfurizing their LSR naphtha, for those refineries where we 

estimate that the LSR naphtha is not being desulfurized today and found that it likely

needs to be. 

As described in Section V.A.4, we are also adopting an ABT program that is 

designed to ease the overall burden on the industry while still achieving the 10 ppm 

annual average sulfur standard for the nation as a whole. Under the ABT program, 

refineries that can reduce sulfur below 10 ppm at a relatively low cost can generate 

credits which can then be acquired by refineries for whom the cost of attaining the 10 

ppm sulfur standard would be higher. These credits can be traded among refineries 

within the same company, or between refiners and importers nationwide. The net effect 

of this credit trading would be to reduce the overall cost of the program. The extent to 

which the ABT provisions reduce the cost of the Tier 3 program depends on the extent 

that the ABT program is used by refiners. As summarized in the alternatives section 

(Section IX), the cost of the 10 ppm Tier 3 sulfur program is 0.65 c/gal assuming 

widespread nationwide credit trading, while if we assume that no credit averaging or 

trading between any individual refinery occurs, the Tier 3 program cost increases to 0.88 

c/gal, a 35% increase. In between those two scenarios is the case that sulfur credits are 

only used for averaging within companies (not traded between refineries owned by

different companies), and we estimated the cost for that scenario at 0.75 c/gal. Since we 

were not sure about the extent that credits were traded under Tier 2 when we conducted 

the cost analysis for the NPRM, we conservatively assumed for the NPRM cost analysis 

that refiners would only volume-average sulfur levels among their refineries, and not 

trade credits between refining companies. However, for the final rule cost analysis we 

evaluated the credit trading that was occurring under Tier 2. We found that 56% of 

credits were in fact being traded between refining companies under Tier 2, with the 

balance being used within refining companies. This demonstrated that credit trading was 

freely occurring between refining companies, supporting the conclusion that credit 

trading would occur nationwide among refineries under Tier 3. We therefore assumed 

nationwide credit trading for our final rule.

To estimate the impact that the ABT program could have on nationwide average 

fuel costs, we began with the refinery-by-refinery costs described in Section VII.B.2.b for 

sulfur reductions down to either 10 ppm or 5 ppm. We then determined the lowest cost 

option among three alternatives for each refinery:

1. The refinery reduces its sulfur to 10 ppm.
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2. The refinery reduces its sulfur to 5 ppm and generates credits for the increment 

between 10 ppm and 5 ppm.

3. The refinery does not lower sulfur, but instead relies on the purchase of credits 

to comply with the 10 ppm standard.

A fourth category applied to refineries whose average gasoline sulfur levels are 

already below 10 ppm (their refineries do not have FCC units). All such refineries were 

assumed to generate credits for the increment between 10 ppm and their current sulfur 

level.

Our methodology was unable to consider a fifth category where a refinery may

utilize less expensive capital and operational changes to reduce their sulfur levels 

partially below Tier 2 levels and rely on purchasing credits only for the remainder. Such 

opportunities are likely to exist at most refineries, but such refinery specific information 

is not available to us. As a result, refineries in the third category are modeled to simply

remain at Tier 2 sulfur levels and incur no capital or operating cost.

To simplify the modeling of how an ABT program might operate, we focused on 

the circumstances that refineries would face in the longer term, specifically after 2020. 

This approach meant that the ABT program modeling did not consider the impact on 

gasoline sulfur levels of delayed compliance for small refiners and small volume 

refineries, nor did it consider the generation and use of any early sulfur credits. 

Moreover, our ABT modeling considered only gasoline sold for use outside of California, 

and only gasoline produced by domestic refineries (not importers).

Our final rule cost analysis is based on a nationwide credit trading scenario. 

Under Tier 2 today, a significant fraction of Tier 2 sulfur credits are bought and sold 

between companies and we believe that this practice will continue (see Section V.D for 

details about the ABT program). To model this phenomenon, we first establish an 

estimated cost for each refinery for reducing its gasoline sulfur down to 10 ppm and to 5 

ppm. Next we ranked the sulfur control strategies for all the refineries in order from 

lowest to highest sulfur control cost per gallon of gasoline and estimated the impact of 

their projected sulfur control strategies on refinery sulfur levels using only one cost 

(either 10 or 5 ppm) for any one refinery. The model then follows this ranking, starting 

with the lowest-cost refineries, and adds refineries and their associated control 

technologies one-by-one until the projected national average gasoline sulfur level reaches 

10 ppm. This modeling strategy projects the sulfur control technology that will be used 

by each refinery, as well as identifies those refineries that are expected to generate credits 

and those that are expected to use credits in lieu of investing in sulfur control. The sum 

of the costs of the refineries expected to invest in further sulfur control provides the 

projected overall cost of the program. 

Based on the results of our cost analysis, we estimate that for the U.S. refining 

industry to achieve a 10 ppm average level with the full benefit of nationwide credit 
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trading, the final sulfur control program would cost on average 0.65 cents per gallon 

when it is fully phased in, assuming that capital investments are amortized at a seven 

percent return on investment before taxes and expressed in 2011 dollars. Refiners would 

be expected to make $2.025 billion in capital investments to achieve this sulfur reduction. 

These capital investments are expected to be made over the 6 years that the Tier 3 

program is expected to be phased in, which would spread out the capital costs to average 

about $330 million per year.

Our cost assessment is likely conservative (i.e., overestimates costs). The capital 

cost estimate is based on vendor data which assumes that refiners are hydrotreating full 

range FCC naphtha. If refiners are indeed undercutting their FCC naphtha at many

refineries (and more will be doing so in the future), many refiners would likely not need 

to make any capital changes. This is because the FCC postreaters were designed when 

refiners were maximizing their gasoline production and hydrotreating full range FCC 

naphtha. When undercutting the FCC naphtha to the diesel pool, refiners cut out about 

16% of the FCC naphtha volume and about half of the sulfur. Thus, if a refiner was able 

to produce 30 ppm gasoline, after fully undercutting their FCC naphtha into the diesel 

pool, they would likely be able to produce 15 ppm sulfur gasoline using their existing 

Tier 2 postreater. They could then use a more active catalyst which likely would enable 

the refinery to achieve 10 ppm gasoline without any capital changes to their FCC 

postreaters. If all refiners were undercutting their FCC naphtha and are able to comply

with Tier 3 without any capital additions to their FCC postreaters, the cost of the program 

would decrease to around 0.4 c/gal. 

Another way that our modeling could be conservative is that refiners are slowly

converting their FCC pretreaters over to mild hydrocrackers to produce more diesel fuel, 

which is in higher demand. We do not know the extent that this is happening, and our 

current analysis assumes that none of the FCC pretreaters have been converted over to 

mild hydrocrackers. However, a cost sensitivity analysis that we conducted with our 

refinery model estimates that if all the FCC pretreaters were converted over to mild 

hydrocrackers, costs of the Tier 3 program would decrease to 0.55 c/gal, assuming 

nationwide credit trading. If we combined the cost reduction of undercutting with the 

mild hydrocracking, the Tier 3 costs would be lower than either of two cost sensitivities 

which were conducted independently.

We also received some comments by API and two of the peer reviewers about our 

octane costs. We will not include all the discussion here about octane costs because we 

do so in detail in the response to peer review comments and in Chapter 5 of the RIA. 

While we are comfortable with the octane costs that we used, we did conduct a sensitivity

at a higher octane cost ($0.5/per octane number barrel instead of $0.31/octane numberbarrel that we used). At the higher octane cost of $0.5/octane number barrel, the Tier 3 

sulfur control costs increases from 0.65 c/gal to 0.73 c/gal. 

We also estimated annual aggregate costs, including the amortized capital costs, 

associated with the new fuel standard. When the 10 ppm gasoline sulfur standard is fully 
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phased in 2020, we estimate that the sulfur standard would cost $790_ million in that 

year. Figure VII-1 shows the distribution of refinery costs over the accumulated gasoline 

volume for the fully phased in 10 ppm sulfur standard.

Figure VII-1 Tier 3 Sulfur Control Costs

Figure VII-1 shows that for almost 20 percent of the gasoline pool, refineries will 

not incur any cost under Tier 3, either because these refineries are already very low in 

sulfur because they do not have FCC units, or because the refineries are purchasing 

credits.540 For another 10 percent of the gasoline pool, the refinery costs are in the 0 –

0.5 cent/gal range. For the next 55 percent of the gasoline pool, the refinery costs are in 

the 0.5 – 1.0 c/gal range. For the last 15 percent of the gasoline pool, the refinery costs 

range from 1.0 to 2.1 c/gal for revamps, with the exception of one refinery at 2.8 c/gal 

representing the cost for the sole grassroots unit which our modeling estimates would 

need to be installed. All other refiners that may otherwise need to install a grassroots 

hydrotreater were able to comply more cheaply through the purchase of credits. 

Figure VII-2 summarizes our estimated U.S. gasoline sulfur levels over the 

accumulated gasoline volume post Tier 3. 

 

540 Refineries purchasing credits will incur a cost for the purchase of the credit, but since we do not know 

what the price of a credit will be, we allocate all the cost for complying with Tier 3 solely on the refineries 

adding capital and incurring operating costs to comply with Tier 3.
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Figure VII-2 Estimated U.S. Gasoline Sulfur Levels Post Tier 3

Figure VII-2 shows that over 80 percent of the gasoline pool would predominately

be either 5 or 10 ppm representing the two sulfur levels to which we assumed that 

refiners would desulfurize their gasoline pool. For the rest of the gasoline pool, the 

refineries are clearly purchasing credits and their sulfur levels range from 10 to nearly 70 

ppm. As discussed earlier, lacking more detailed refinery-specific information, for these 

refineries we assumed that they take no action to reduce their gasoline sulfur below their 

Tier 2 levels. In reality these refineries are likely to take some very cost-effective steps 

to partially reduce their gasoline sulfur and not rely solely on credits to demonstrate 

compliance with Tier 3. Were we able to model such refinery changes, it would only

serve to further lower our projected costs. 

4. Other Cost Estimates

Three other cost studies were conducted to estimate the cost of additional 

reduction in gasoline sulfur. All of these studies show average costs of less than 2 cents 

per gallon. 

One of these studies was conducted in October 2011 by the International Council 

for Clean Transportation (ICCT). 541 ICCT retained Mathpro for this analysis. ICCT had 

 

541 Mathpro (October 2011). Refining Economics of a National Low Sulfur, Low RVP Gasoline Standard, 

Performed for The International Council for Clean Transportation, Available at: 

http://www.theicct.org/sites/default/files/publications/ICCT04_Tier3_Report_Final_v4_All.pdf. Accessed 

December 12, 2011. 
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Mathpro analyze a 10 ppm average gasoline sulfur standard in PADDs 1 – 4 (generally

speaking, PADDs 1 – 4 represents the part of the U.S. east of, and including, the Rocky 

Mountain states). The cost presented by ICCT is that complying with a 10 ppm average 

sulfur standard would cost refiners on average 0.8 cents per gallon. This cost was 

calculated based on a before-tax 7 percent return on investment, the same capital 

amortization basis that we use for our cost analysis. The cost of a 10 ppm average 

gasoline sulfur control standard estimated by ICCT is very close to our cost estimate. 

API retained Baker and O’Brien to study the cost of additional sulfur control 

using a refinery-by-refinery cost approach with Baker and O’Brien’s Prism model.542 

API studied a 10 ppm average gasoline sulfur standard, however, API included a very

stringent 20 ppm cap standard which did not allow for an ABT program to optimize 

refinery investments and minimize overall costs (an estimate of the impact of the 20 ppm 

cap standard using API information is presented below). 

API made a series of conclusions based on the study. Perhaps the most important 

conclusion is that no refinery would shut down as a result of the 10 ppm gasoline sulfur 

control standard, even though API did not study the flexibilities of an ABT program and 

used excessively high capital costs for a grassroots FCC postreater (see below). API did 

not report average costs, but reported the marginal costs for the cost study. Marginal 

costs reflect the cost of the program to the refinery or refineries which would incur the 

highest costs, assuming that the highest cost refineries would set the price (or in this case, 

the price increase) of gasoline. Since they assumed a 20 ppm cap precluding refiners 

from utilizing the ABT program, it required virtually all refiners to incur capital costs 

thereby driving up marginal costs. The report concluded that marginal costs after the 

imposition of a 10 ppm gasoline sulfur program would increase the price of gasoline by 6 

to 9 cents per gallon in most markets. API did not define how its statement “in most 

markets” would apply to the U.S. gasoline supply. API also did not provide any

justification why it assumed that the refineries that would experience the highest 

desulfurization cost under Tier 3 would also be the same refineries which set the gasoline 

price in the gasoline market today. 

Although API did not provide an average gasoline desulfurization cost in its 

report, we could calculate an average cost based on the gasoline volume and total annual 

costs provided. The total cost reported in the report for the 10 ppm average gasoline 

sulfur standard is $2390MM/yr and the non-California gasoline volume is 7343 thousand 

barrels per day. This results in an average per-gallon desulfurization cost of $0.89/bbl or 

2.12 c/gal. The difference between the average cost and marginal cost (price increase) 

that API is projecting is profit. Thus, API’s analysis would suggest that the oil industry 

 

542 Baker and O’Brien, Addendum to Potential Supply and Cost Impacts of Lower Sulfur, Lower RVP 

Gasoline; prepared for The American Petroleum Institute. March 2012. Available at: 

http://www.api.org/Newsroom/upload/110715_LowerSulfur_LowerRVP_Final.pdf. 
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would profit from 10 ppm low sulfur standard by roughly 4 to 7 cents per gallon, or 

roughly $4 to $8 billion dollars per year as a result of gasoline sulfur control. 

The average cost of the 10 ppm average gasoline sulfur standard described above 

was calculated using API’s methodology for amortizing capital investments. To assess 

the costs consistent with OMB’s guidance for our rulemakings and to allow a direct 

comparison between the API cost study and our cost study, we adjusted the API costs to 

be on a similar basis as our costs. We adjusted the API costs to reflect a before-tax 7 

percent return on investment (ROI) for capital invested for the hydrotreaters and 

hydrogen plants instead of the after-tax 10 percent ROI used by API. This lowered the 

API estimated costs from 2.12 c/gal to 1.58 c/gal. API’s 1.58 cents per gallon cost is still 

higher than our 0.65 c/gal cost with an ABT program that assumes nationwide trading of 

credits, and higher than our 0.86 c/gal for the case which assumes no ABT program. The 

remaining difference between our estimated costs and those by API are driven by API’s 

assumptions for the capital costs that would be incurred for adding grassroots FCC 

postreaters, or revamping existing ones. 

While little detail is provided by API about what hardware comprises their 

desulfurization units, the inside battery limits (ISBL) and total capital costs for the FCC 

postreaters and FCC pretreaters are provided in API’s report. API’s FCC pretreaters 

capital costs are consistent with the capital costs that we have used for this unit. 

However, the FCC postreater costs used by API are much higher than what we used and 

have been used in the past by others. API’s capital cost for a grassroots FCC postreater is 

$228 million for a 35,000 bbl/day unit, or $6540 per/bbl per day. API’s capital cost 

includes the outside battery limit (OSBL) costs. 

We were able to obtain a document which shed some light on the methodology

that API used to develop its FCC postreater capital costs.543 When the proposed rule was 

being reviewed by the Office of Management Budget (OMB) at the end of 2012, API

provided to OMB a document which provided answers to questions that EPA and EIA 

posed to API and Baker and O’Brien back in mid-2011 when API was about to release its 

study of gasoline sulfur control costs. According to the document, API collected 

investment cost information for 5 FCC naphtha hydrotreater projects that were apparently

completed by refiners to comply with Tier 2, and not the low severity capital projects that 

refiners would use to comply with Tier 3. No specific information was provided for any 

of those projects to determine whether each of those projects was typical, or if they

included atypical costs add-ons for other refinery upgrades, which is common when 

refiners make changes in response to an environmental regulation. API adjusted the 

capital cost to be on a 35kbbl/day basis and the capital costs were inflated from the year 

that the project was constructed in the 2003 to 2005 timeframe, to mid-2009 dollars using 

 

543 Document entitled “Follow-up Questions from EPA-EIA” (no other information provided on the 

document).
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the Nelson-Farrar Refinery Construction Index. API then reviewed the final capital 

investment costs for FCC postreaters with several other members that had recently 

installed FCC postreaters. One refiner which had presented an itemized list of capital 

costs for a recent FCC postreater installation stated that the costs for their recent FCC 

postreater installation were two times higher than the Nelson-Farrar adjusted costs, so 

API doubled the costs. The information provided did not state whether these later 

installations used to double the estimated postreater costs were in the U.S. where 

engineering and construction are readily available or overseas where most recent FCC 

postreater installations have been occurring and where the installation costs could be 

much higher.

In contrast, the ISBL capital cost that we used for a grassroots FCC postreater is 

$1500/bbl-day for a 30,000 bbl/day grassroots unit, which increases to $2430/bbl/day

when the offsite and contingency costs are added on. Thus, the API capital costs of 

$6540 are about 2 and one half times higher than the capital costs that we are using for a 

grassroots FCC postreater. To check our capital costs, we found other capital cost 

estimates to which we could compare our costs, including the capital costs used by the 

National Petroleum Council when it studied the cost of gasoline desulfurization prior to 

Tier 2. Compared to the average of the rest of the capital cost estimates, the API capital 

cost for FCC postreater is about four times higher. Compared to the next highest cost 

estimate, which is the FCC postreater capital cost from the Jacobs data base in the 

Haverly refinery cost model that we use,544 the API capital costs are almost two times 

higher. 

As alluded to earlier, an important distinction must be made with respect to the 

severity of desulfurization for the capital cost comparison made for complying with Tier 

2 versus Tier 3. For complying with the Tier 2 gasoline sulfur standard (Jacobs and NPC 

costs), a typical refinery would have installed an FCC postreater to desulfurize the FCC 

naphtha from about 800 ppm down to about 75 ppm, a 725 ppm, or a 91 percent sulfur 

reduction. In the case of a grassroots postreater that would be installed for Tier 3, the 

postreater would treat FCC naphtha already low in sulfur due to the pretreater installed 

before the FCC unit (these refineries are currently complying with Tier 2 using an FCC 

pretreater). Thus, the new grassroots FCC postreater would only have to reduce the FCC 

naphtha from 100 ppm to 25 ppm, a much smaller 75 ppm or 75 percent sulfur reduction. 

A grassroots FCC postreater installed for Tier 2 would typically remove 10 times more 

sulfur than one installed for Tier 3. This is important because a significant portion of the 

FCC postreater capital cost is devoted to avoiding the recombination reactions which 

occur when hydrogen sulfide concentrations are high and react with the olefins contained 

in the FCC naphtha. Thus, a grassroots FCC postreater installed for Tier 3 would be 

expected to be significantly lower in capital cost compared to a Tier 2 FCC postreater. 

 

544 The installed capital cost for an FCC postreater from the Jacobs data base was adjusted to current year 

dollars. This estimated installed capital cost is several years old and may not represent Jacobs current cost 

estimate for a FCC postreater.
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When API presented the costs, they stated that their grassroots capital costs were based 

on an actual installation for the Tier 2 program. This is likely one important reason why

the capital costs used by API for its cost study of the Tier 3 program are so high. Another 

way to assess the API capital cost for the FCC postreaters is to compare it to the FCC 

pretreater cost that API is using. FCC pretreaters are much higher pressure units and use 

more expensive metallurgy than FCC postreaters and, for these two reasons, are much 

more expensive than FCC postreaters on a per-barrel basis. However, API’s FCC 

postreater capital costs are about 50 percent more expensive than its own FCC pretreater 

capital costs, which is inconsistent with the design requirements of the units. 

API’s estimated range of capital cost for revamping an FCC postreater is also 

higher than our range of capital cost for revamping an FCC postreater, when assessing 

the revamped costs as a percentage of the capital cost for a grassroots unit. API estimates 

that revamping an FCC postreater would cost 30 to 70 percent of the capital cost for a 

grassroots FCC unit. Our capital cost estimate for revamping an FCC naphtha postreaters 

range from 17 to 50 percent of the capital cost for a grassroots FCC postreater, however, 

most of the revamps are estimated to cost at the lower end of that range. 

As discussed above, an important reason why API’s projected capital costs for 

complying with Tier 3 are so high is that API assumed a 20 ppm cap standard in addition 

to the 10 ppm average standard that it studied. The 20 ppm cap standard eliminates the 

possibility of realizing the cost savings of an ABT program. After we proposed the Tier 

3 rule, API presented to EPA, in its comments on the proposed rulemaking, its estimate 

for the cost of finalizing a more stringent cap standard. The study, which was contracted 

to the Turner, Mason & Company, estimated that a 20 ppm cap standard would increase 

the capital cost of complying with a 10 ppm average standard by $6.1 billion. If we 

subtract the $6.1 billion in capital costs attributed to the 20 ppm cap standard from the 

$9.8 billion in total capital costs from API’s Addendum report which estimated the cost 

of complying with Tier 3, and adjust the fixed operating costs accordingly, the API

estimated average cost (not marginal cost) for complying with Tier 3 decreases to 0.97 

c/gal. In addition to the questionable capital costs assumed for FCC postreaters as 

discussed above, this information from API on its estimated cost of complying with a 20 

ppm cap standard helps to answer an important question of why API estimated average 

cost was still higher than the other studies after other cost adjustments were made. This 

final adjustment to the API costs makes the estimated API costs for complying with Tier 

3 right in line with the other cost studies. This adjusted API cost, however, still does 

include the cost saving aspects of credit averaging and trading since the API analysis 

assumed that each refinery meets the 10 ppm average sulfur standard. Thus, to compare 

this most recent cost adjustment of API costs to our cost study, our 0.87 c/gal cost for no 

ABT program would be the most appropriate cost for comparison (see Chapter IX for 

alternative costs), The adjusted API cost and our cost are only 0.1 c/gal different.

Our assessment of the API study is supported by work performed by The 

Emissions Control Technology Association (ECTA) which retained personnel within 

Navigant Economics. That study assessed the costs of a 10 ppm average gasoline sulfur 
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standard and also evaluated the ICCT and API cost studies.545 The authors made a 

number of conclusions. After reviewing both the ICCT and API studies, the authors 

found that a primary difference in estimated costs between the two studies was the capital 

costs. The authors contacted vendor companies that license FCC postreater technologies 

and surveyed the companies to find out what the capital costs are for a FCC postreater. 

As a result of the survey, the report authors concluded that API’s capital costs were too 

high, and those used in the ICCT study were about right. The authors found that Baker 

and O’Brien has a history of exaggerating the economic impacts of EPA rules, citing the 

costs and other impacts of its analysis of the 2007 on-highway heavy-duty proposed 

rulemaking. The authors concluded that the impact of a 10 ppm gasoline sulfur standard 

on the average refining cost would likely be closer to the 1 cent per gallon estimate by the 

ICCT study. Furthermore, the report’s authors also pointed out that the marginal cost 

analysis conducted by API did not consider the averaging banking and trading (ABT) 

program that we adopted, which would reduce the marginal costs of the Tier 3 final rule.

C. Summary of Program Costs

While the estimated costs for the separate vehicle and fuel programs are presented 

in Sections VII.A and VII.B, respectively, it is useful to present the combined cost 

estimates representing the full Tier 3 program. 

We have chosen to use an annual cost format to represent the combined vehicle 

and program costs because this approach provides the most straightforward means for 

comparing vehicle costs to fuel costs, and for demonstrating the total cost impact of our 

final program. This approach to combined costs also provides a basis for comparing the 

program costs to the projected benefits as described more fully in Section VIII.

Table VII-6 below shows our estimated program costs by year. The total program 

costs for the final rule are lower than those projected for the proposal due to several 

reasons. First, the vehicle program costs are lower due in part to applying the per vehicle 

costs to vehicles excluding those sold in California and the states that have adopted the 

LEV III program. A complete discussion of the differences in vehicle costs between the 

proposal and final rule are outlined above in Section VII.A.1. Second, the fuel program 

costs are also lower than the values projected for the proposal due to lower refinery cost 

estimates, as discussed above in Section VII.B. In addition, the annual fuel consumption 

projections are lower in the final rule because they reflect the inclusion of the Light-Duty

Greenhouse Gas and Fuel Economy Standards for 2017-2025 model years. Complete 

details of this analysis can be found in the RIA Chapter 8.

Table VII-6 Total Annual Vehicle and Fuel Control Costs, 2011$

a

 

545 Schink, George R., Singer, Hal J., Economic Analysis of the Implications of Implementing EPA’s Tier 3 

Rules, prepared for the Emissions Control Technology Association, June 14, 2012.
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Year Vehicle 

Exhaust 

Emission 

Control Costs

($Million)

Vehicle Evaporative 

Emission Control 

Costs

($Million)

Vehicle 

Operating 

Costs 

($Million)

Facility 

Costs 

($Million)

Fuel Sulfur 

Control Costs

($Million)

Total 

Program 

Costs 

($Million)

2016 $0 $0 $0 $21 $0 $21

2017 $268 $26 $0 $4 $804 $1,101

2018 $539 $73 -$1 $4 $799 $1,414

2019 $579 $72 -$2 $4 $794 $1,447

2020 $599 $98 -$3 $4 $787 $1,484

2021 $630 $97 -$5 $4 $778 $1,503

2022 $640 $121 -$6 $4 $768 $1,526

2023 $639 $116 -$8 $4 $758 $1,509

2024 $653 $114 -$9 $4 $748 $1,509

2025 $668 $113 -$11 $4 $737 $1,510

2030 $664 $113 -$19 $4 $696 $1,457

a These estimates include costs associated with: (a) the Tier 3 vehicle standards in all states except 

California and the states that have adopted the LEV III program; and, (b) the Tier 3 fuel standards in all 

states except California.

VIII.What are the Estimated Benefits of the Rule?

This section presents EPA’s analysis of the criteria pollutant-related health and 

environmental impacts that will occur as a result of the final Tier 3 standards. The 

vehicles and fuels subject to the standards are significant sources of mobile source air 

pollution such as direct PM, NOX, SOX, VOCs and air toxics. The standards will reduce 

exhaust and evaporative emissions of these pollutants from vehicles. Emissions of NOX

(a precursor to ozone formation and secondarily-formed PM2.5), SOX (a precursor to 

secondarily-formed PM2.5), VOCs (a precursor to ozone formation and, to a lesser degree, 

secondarily-formed PM2.5) and directly-emitted PM2.5 contribute to ambient 

concentrations of PM2.5 and ozone. Exposure to ozone, PM2.5, and air toxics is linked to 

adverse human health impacts such as premature deaths as well as other important public 

health and environmental effects.

For the final rulemaking, we have estimated the health and environmental impacts 

in 2030, representing projected impacts associated with a year when the program is fully

implemented and when most of the fleet is turned over. Overall, we estimate that the 

standards will lead to a net decrease in PM2.5- and ozone-related health impacts. The 

estimated decrease in population-weighted national average PM2.5 exposure results in a 

net decrease in adverse PM-related human health impacts (the decrease in national 

population-weighted annual average PM2.5 is 0.04 μg/m3in 2030). The estimated 

decrease in population-weighted national average ozone exposure results in a net 
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decrease in ozone-related health impacts (population-weighted maximum 8-hour average 

ozone decreases by 0.32 ppb in 2030).546

Using the lower end of EPA’s range of preferred premature mortality estimates

(Krewski et al., 2009 for PM2.5 and Bell et al., 2004 for ozone),547,548 we estimate that by

2030, implementation of the standards will reduce approximately 770 premature 

mortalities annually and will yield between $6.7 and $7.4 billion in total annual benefits, 

depending on the discount rate used.549 The upper end of the range of avoided premature 

mortality estimates associated with the standards (based on Lepeule et al., 2012 for PM2.5

and Levy et al., 2005 for ozone)550,551 results in approximately 2,000 premature 

mortalities avoided in 2030 and will yield between $18 and $19 billion in total benefits. 

Thus, even using the lower end of the range of premature mortality estimates, the health 

impacts of the final standards presented in this rule are projected to be substantial.

We note that of necessity, decisions on the emissions and other elements used in 

the air quality modeling were made early in the analytical process for the final 

rulemaking. For this reason, the modeled changes in emissions used to support the air 

quality and benefits analyses are slightly different than those used to represent the final 

emissions impacts of the Tier 3 standards. The magnitude of the differences is small, 

however, and for that reason we do not expect these differences to materially impact our 

cost-benefit conclusions. See Chapter 7.2.1.1 of the RIA for more details.

 

546 Note that the national, population-weighted PM2.5 and ozone air quality metrics presented in this Section 

represent an average for the entire, gridded U.S. CMAQ domain. These are different than the populationweighted PM2.5 and ozone design value metrics presented in Chapter 7, which represent the average for 

areas with a current air quality monitor.

547 Krewski, D., M. Jerret, R.T. Burnett, R. Ma, E. Hughes, Y. Shi, et al. (2009). Extended follow-up and 

spatial analysis of the American Cancer Society study linking particulate air pollution and mortality. HEI 

Research Report, 140,Health Effects Institute, Boston, MA.

548 Bell, M.L., et al. (2004). Ozone and short-term mortality in 95 U.S. urban communities, 1987-

2000.Journal of the American Medical Association, 292(19), 2372-2378.

549 The monetized value of PM2.5-related mortality accounts for a twenty-year segmented cessation lag. To 

discount the value of premature mortality that occurs at different points in the future, we apply both a 3 and 

7 percent discount rate. We also use both a 3 and 7 percent discount rate to value PM-related nonfatal heart 

attacks (myocardial infarctions). Nonfatal myocardial infarctions (MI) are valued using age-specific costof-illness values that reflect lost earnings and direct medical costs over a 5-year period following a nonfatal 

MI.

550 Lepeule J, Laden F, Dockery D, Schwartz J (2012). Chronic Exposure to Fine Particles and Mortality: 

An Extended Follow-Up of the Harvard Six Cities Study from 1974 to 2009. Environ Health Perspect. 

Jul;120(7):965-70.

551 Levy, J.I., S.M. Chemerynski, and J.A. Sarnat. (2005). Ozone exposure and mortality: an empiric bayes 

metaregression analysis. Epidemiology. 16(4), 458-68.
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A. Overview

We base our analysis of the program’s impact on human health on peer-reviewed

studies of air quality and human health effects.552,553 These methods are described in 

more detail in Chapter 8 of the RIA. Our benefits methods are consistent with the RIA 

that accompanied the final revisions to the National Ambient Air Quality Standards 

(NAAQS) for Particulate Matter and the final ozone NAAQS. To model the ozone and 

PM air quality impacts of the final standards, we used the Community Multiscale Air 

Quality (CMAQ) model (see Chapter 7.2.2 of the RIA that accompanies this preamble). 

The modeled ambient air quality data serves as an input to the Environmental Benefits 

Mapping and Analysis Program version 4.065 (BenMAP).554 BenMAP is a computer 

program developed by the U.S. EPA that integrates a number of the modeling elements 

used in previous analyses (e.g., interpolation functions, population projections, health 

impact functions, valuation functions, analysis and pooling methods) to translate modeled 

air concentration estimates into health effects incidence estimates and monetized benefits 

estimates.

The range of total monetized ozone- and PM-related health impacts projected in 

2030 is presented in Table VIII-1. We present total benefits based on the PM- and 

ozone-related premature mortality function used. The benefits ranges therefore reflect 

the addition of each estimate of ozone-related premature mortality (each with its own row 

in Table VIII-1) to estimates of PM-related premature mortality. 

Table VIII-1 Estimated 2030 Monetized PM-and Ozone-Related Health Benefits

2030 Total Ozone and PM Benefits – PM Mortality Derived from American Cancer Society Analysis and 

Six-Cities Analysisa

Premature Ozone 

Mortality Function

Reference Total Benefits

(Billions, 2011$, 3% 

Discount Rate)b,c

Total Benefits

(Billions, 2011$, 7% 

Discount Rate) b,c

Multi-city analyses Bell et al., 2004 Total: $7.4 - $15

PM: $6.0 - $14

Ozone: $1.1

Total: $6.7 - $14

PM: $5.4 - $12

Ozone: $1.1

Huang et al., 2005 Total: $7.9 - $16

PM: $6.0 - $14

Ozone: $1.7

Total: $7.3 - $14

PM: $5.4 - $12

Ozone: $1.7

Schwartz, 2005 Total: $8.0 - $16

PM: $6.0 - $14

Total: $7.3 - $14

PM: $5.4 - $12

 

552 U.S. Environmental Protection Agency. (2012). Regulatory Impact Analysis for the Final Revisions to 

the National Ambient Air Quality Standards for Particulate Matter. Prepared by: Office of Air and 

Radiation, EPA-452/R-12-005. Retrieved August 14, 2013 at http://www.epa.gov/ttn/ecas/ria.html

553 U.S. Environmental Protection Agency. (2008). Final Ozone NAAQS Regulatory Impact Analysis. 

Prepared by: Office of Air and Radiation, Office of Air Quality Planning and Standards. Retrieved August 

14, 2013 at http://www.epa.gov/ttn/ecas/ria.html

554 Information on BenMAP, including downloads of the software, can be found at 

http://www.epa.gov/ttn/ecas/ benmodels.html.
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Ozone: $1.7 Ozone: $1.7

Meta-analyses Bell et al., 2005 Total: $9.8 - $18

PM: $6.0 - $14

Ozone: $3.6

Total: $9.2 - $16

PM: $5.4 - $12

Ozone: $3.6

Ito et al., 2005 Total: $11 - $19

PM: $6.0 - $14

Ozone: $4.9

Total: $11 - $18

PM: $5.4 - $12

Ozone: $4.9

Levy et al., 2005 Total: $11 - $19

PM: $6.0 - $14

Ozone: $5.0

Total: $11 - $18

PM: $5.4 - $12

Ozone: $5.0

.

a Total includes premature mortality-related and morbidity-related ozone and PM2.5 estimated benefits. 

Range was developed by adding the estimate from the ozone premature mortality function to the estimate

of PM2.5-related premature mortality derived from either the ACS study (Krewski et al., 2009) or the SixCities study (Lepeule et al., 2012). Range also reflects alternative estimates of non-fatal heart attacks 

avoided based on either Peters et al. (2001) or a pooled estimate of four studies.

b Note that total benefits presented here do not include a number of unquantified benefits categories. A 

detailed listing of unquantified health and welfare effects is provided in Table VIII-2.

c Results reflect the use of both a 3 and 7 percent discount rate, as recommended by EPA’s Guidelines for 

Preparing Economic Analyses and OMB Circular A-4. Results are rounded to two significant digits for 

ease of presentation and computation. Totals may not sum due to rounding.

The benefits analysis presented in this chapter incorporates an array of policy and 

technical changes that the Agency has adopted since the Tier 3 proposal’s draft RIA. 

These changes reflect EPA’s work to update PM-related benefits reflected in the most 

recent PM NAAQS.555 Below we note the aspects of this analysis that differ from the 

Tier 3 proposal’s draft RIA:556

1. Incorporation of the newest American Cancer Society (ACS) mortality study 

and newest Harvard Six Cities mortality study. In 2012, Lepeule et al. published an 

extended analysis of the Six Cities cohort.557 Compared to the study it replaces

(Laden et al., 2006),

558 this new analysis follows the cohort for a longer time and 

includes more years of PM2.5 monitoring data. The all-cause PM2.5 mortality risk 

coefficient drawn from Lepeule et al. is roughly similar to the Laden et al. risk 

coefficient applied in the EPA’s recent analyses of long-term PM2.5 mortality and 

has narrower confidence intervals. 

In 2009, the Health Effects Institute published an extended analysis of the ACS 

cohort (Krewski et al., 2009).559 Compared to the study it replaces (Pope et al., 

2002),560 this new analysis incorporates a number of methodological 

 

555 U.S. Environmental Protection Agency. (2012). Regulatory Impact Analysis for the Final Revisions to 

the National Ambient Air Quality Standards for Particulate Matter. Prepared by: Office of Air and 

Radiation, EPA-452/R-12-005. Retrieved August 14, 2013 at http://www.epa.gov/ttn/ecas/ria.html

556 U.S. Environmental Protection Agency. (2013). Draft Regulatory Impact Analysis: Tier 3 Motor 

Vehicle Emission and Fuel Standards. Prepared by: Office of Air and Radiation. EPA-420-D-13-002. 

Retrieved October 18, 2013 at http://www.epa.gov/otaq/documents/tier3/420d13002.pdf
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Page 457 of 1039

improvements.

561 The all-cause PM2.5 mortality risk estimate drawn from Krewski 

et al. (2009) is identical to the Pope et al. (2002) risk estimate applied in recent EPA 

analyses of long-term PM2.5 mortality but has narrower confidence intervals.

2. Updated health endpoints. We have removed the quantification of chronic 

bronchitis from our main analysis. This change is consistent with the findings of the

PM Integrated Science Assessment (ISA) that the evidence for an association 

between long-term exposure to PM2.5 and respiratory effects is more tenuous.

562

3. Updated demographic data. We updated the population demographic data in 

BenMAP to reflect the 2010 Census and future projections based on economic 

forecasting models developed by Woods and Poole, Inc.563 These data replace the 

earlier demographic projection data from Woods and Poole (2011).

564

4. Incorporation of new morbidity studies. Since the publication of the 2004 

Criteria Document for Particulate Matter,

565 the publication of the more recent PM 

ISA,566 and the Provisional Assessment of Recent Studies on Health Effects of 

 

557 Lepeule J, Laden F, Dockery D, Schwartz J. 2012. Chronic Exposure to Fine Particles and Mortality: 

An Extended Follow-Up of the Harvard Six Cities Study from 1974 to 2009. Environ Health Perspect. 

Jul;120(7):965-70.

558 Laden, F., J. Schwartz, F.E. Speizer, and D.W. Dockery. 2006. “Reduction in Fine Particulate Air 

Pollution and Mortality.” American Journal of Respiratory and Critical Care Medicine 173:667-672.

559 Krewski, D., M. Jerret, R.T. Burnett, R. Ma, E. Hughes, Y. Shi, et al. (2009). Extended follow-up and 

spatial analysis of the American Cancer Society study linking particulate air pollution and mortality. HEI 

Research Report, 140,Health Effects Institute, Boston, MA.

560 Pope, C.A., III, R.T. Burnett, M.J. Thun, E.E. Calle, D. Krewski, K. Ito, and G.D. Thurston. 2002. 

“Lung Cancer, Cardiopulmonary Mortality, and Long-term Exposure to Fine Particulate Air Pollution.” 

Journal of the American Medical Association 287:1132-1141.

561 Refer to the 2012 PM NAAQS RIA for more detail regarding the studies themselves.

562 U.S. Environmental Protection Agency (U.S. EPA). 2009. Integrated Science Assessment for Particulate 

Matter (Final Report). EPA-600-R-08-139F. National Center for Environmental Assessment—RTP 

Division. December. Available on the Internet at 

<http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=216546>.

563 Woods & Poole Economics Inc. 2012. Population by Single Year of Age. CD-ROM. Woods & Poole 

Economics, Inc. Washington, D.C.

564 Woods & Poole Economics, Inc. (2011). 2012 Complete Economic and Demographic Data Source 

(CEDDS).

565 U.S. Environmental Protection Agency (U.S. EPA). 2004. Air Quality Criteria for Particulate Matter. 

National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental 

Protection Agency, Research Triangle Park, NC EPA/600/P-99/002bF. Available on the Internet at 

<http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=87903>.

566 U.S. Environmental Protection Agency (U.S. EPA). 2009. Integrated Science Assessment for Particulate 

Matter (Final Report). EPA-600-R-08-139F. National Center for Environmental Assessment—RTP 

Division. December. Available on the Internet at 

<http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=216546>.
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Page 458 of 1039

Particulate Matter Exposure (“Provisional Assessment”),567 the epidemiological 

literature has produced several new studies examining the association between 

short-term PM2.5 exposure and acute myocardial infarctions, respiratory and 

cardiovascular hospitalizations, respiratory and cardiovascular emergency

department visits, acute respiratory symptoms and exacerbation of asthma, 

respiratory and cardiovascular hospitalizations. Upon careful evaluation of this new 

literature, we added several new studies to our health impact assessment; in many

cases we have replaced older single-city time-series studies with newer multi-city

time-series analyses.

5. Updated the survival rates for non-fatal acute myocardial infarctions. Based on 

recent data from Agency for Healthcare Research and Quality’s Healthcare 

Utilization Project National Inpatient Sample database,568 we identified death rates 

for adults hospitalized with acute myocardial infarction stratified by age. These 

rates replace the survival rates from Rosamond et al. (1999).569

6. Updated hospital cost-of-illness (COI), including median wage data. In 

previous benefits analyses, estimates of hospital charges and lengths of hospital 

stays were based on discharge statistics provided by the Agency for Healthcare 

Research and Quality’s Healthcare Utilization Project National Inpatient Sample 

(NIS) database for 2000.570 The version of BenMAP (version 4.0.65) used in this 

analysis updated this information to use the 2007 database. The data source for the 

updated median annual income is the 2007 American Community Survey.

The benefits in Table VIII-1 include all of the estimated human health impacts we 

are able to quantify and monetize at this time. However, the full complement of human 

health effects associated with PM, ozone and other criteria pollutants remain unquantified 

because of current limitations in methods and/or available data. We have not quantified a 

number of known or suspected health effects linked with these pollutants for which 

appropriate health impact functions are not available or which do not provide easily 

interpretable outcomes (e.g., changes in heart rate variability). These are listed in Table 

 

567 U.S. Environmental Protection Agency (U.S. EPA). 2012. Provisional Assessment of Recent Studies on 

Health Effects of Particulate Matter Exposure. EPA/600/R-12/056A. National Center for Environmental 

Assessment—RTP Division. December.

568 Agency for Healthcare Research and Quality (AHRQ). 2009. HCUPnet, Healthcare Cost and Utilization 

Project. Rockville, MD. Available on the Internet at <http://hcupnet.ahrq.gov>.American Lung Association 

(ALA). 1999. Chronic Bronchitis. Available on the Internet at 

<http://www.lungusa.org/diseases/lungchronic.html>.

569 Rosamond, W., G. Broda, E. Kawalec, S. Rywik, A. Pajak, L. Cooper, and L. Chambless. 1999. 

“Comparison of Medical Care and Survival of Hospitalized Patients with Acute Myocardial Infarction in 

Poland and the United States.” American Journal of Cardiology 83:1180-1185.

570 Agency for Healthcare Research and Quality (AHRQ). 2000. HCUPnet, Healthcare Cost and Utilization 

Project. Rockville, MD. Available on the Internet at <http://hcupnet.ahrq.gov>.
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VIII-2. As a result of these omissions, the health benefits quantified in this section are 

likely underestimates of the total benefits attributable to the final standards.

Table VIII-2 Estimated Quantified and Unquantified Health Effects

BENEFITS 

CATEGORY

SPECIFIC EFFECT EFFECT HAS 

BEEN 

QUANTIFIED

EFFECT HAS 

BEEN 

MONETIZED

MORE 

INFORMATION

Improved Human Health

Reduced 

incidence of 

premature 

mortality and 

morbidity from 

exposure to PM2.5

Adult premature mortality based on 

cohort study estimates and expert 

elicitation estimates (age >25 or age 

>30)

  PM NAAQS RIA, 

Section 5.6

Infant mortality (age <1)   PM NAAQS RIA, 

Section 5.6

Non-fatal heart attacks (age > 18)   PM NAAQS RIA, 

Section 5.6

Hospital admissions—respiratory (all 

ages)

  PM NAAQS RIA, 

Section 5.6

Hospital admissions—cardiovascular 

(age >20)

  PM NAAQS RIA, 

Section 5.6

Emergency department visits for 

asthma (all ages)

  PM NAAQS RIA, 

Section 5.6

Acute bronchitis (age 8–12)   PM NAAQS RIA, 

Section 5.6

Lower respiratory symptoms (age 7–

14)

  PM NAAQS RIA, 

Section 5.6

Upper respiratory symptoms 

(asthmatics age 9–11)

  PM NAAQS RIA, 

Section 5.6

Asthma exacerbation (asthmatics age 

6–18)

  PM NAAQS RIA, 

Section 5.6

Lost work days (age 18–65)   PM NAAQS RIA, 

Section 5.6

Minor restricted-activity days (age 

18–65)

  PM NAAQS RIA, 

Section 5.6

Chronic Bronchitis (age >26) — — PM NAAQS RIA, 

Section 5.6c
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Page 460 of 1039

BENEFITS 

CATEGORY

SPECIFIC EFFECT EFFECT HAS 

BEEN 

QUANTIFIED

EFFECT HAS 

BEEN 

MONETIZED

MORE 

INFORMATION

Emergency department visits for 

cardiovascular effects (all ages)

— — PM NAAQS RIA, 

Section 5.6c

Strokes and cerebrovascular disease 

(age 50–79)

— — PM NAAQS RIA, 

Section 5.6c

Other cardiovascular effects (e.g., 

other ages)

— — PM ISAa

Other respiratory effects (e.g., 

pulmonary function, non-asthma ER 

visits, non-bronchitis chronic 

diseases, other ages and populations)

— — PM ISAa

Reproductive and developmental 

effects (e.g., low birth weight, preterm births, etc.)

— — PM ISAa,b

Cancer, mutagenicity, and 

genotoxicity effects

— — PM ISAa,b

Reduced 

incidence of 

premature 

mortality and 

morbidity from 

exposure to 

ozone

Premature mortality based on shortterm study estimates (all ages)  Ozone ISA

Premature mortality based on longterm study estimates (age 30–99)— — Ozone ISAc

Hospital admissions—respiratory 

causes (age > 65)

  Ozone ISA

Hospital admissions—respiratory 

causes (age <2)

  Ozone ISA

Emergency department visits for 

asthma (all ages)

  Ozone ISA

Minor restricted-activity days (age 

18–65)

  Ozone ISA

School absence days (age 5–17)   Ozone ISA

Decreased outdoor worker 

productivity (age 18–65)

  Ozone ISA

Other respiratory effects (e.g., 

premature aging of lungs)

— — Ozone ISAa

Cardiovascular and nervous system 

effects

— — Ozone ISAb

Reproductive and developmental — — Ozone ISAb
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BENEFITS 

CATEGORY

SPECIFIC EFFECT EFFECT HAS 

BEEN 

QUANTIFIED

EFFECT HAS 

BEEN 

MONETIZED

MORE 

INFORMATION

effects

Reduced 

incidence of 

morbidity from 

exposure to air 

toxics

Cancer (benzene, 1,3-butadiene, 

formaldehyde, acetaldehyde)

Anemia (benzene)

Disruption of production of blood 

components (benzene)

Reduction in the number of blood 

platelets (benzene)

Excessive bone marrow formation 

(benzene)

Depression of lymphocyte counts 

(benzene)

Reproductive and developmental 

effects (1,3-butadiene)

Irritation of eyes and mucus 

membranes (formaldehyde)

Respiratory irritation (formaldehyde)

Asthma attacks in asthmatics 

(formaldehyde)

Asthma-like symptoms in nonasthmatics (formaldehyde)

Irritation of the eyes, skin, and 

respiratory tract (acetaldehyde)

Upper respiratory tract irritation and 

congestion (acrolein)

— — IRISa,b

a We assess these benefits qualitatively because we do not have sufficient confidence in available data or 

methods.

b We assess these benefits qualitatively because current evidence is only suggestive of causality or there 

are other significant concerns over the strength of the association.

c We assess these benefits qualitatively due to time and resource limitations for this analysis.

While there would be impacts associated with reductions in air toxic pollutant 

emissions that result from the final standards, we do not attempt to quantify and monetize 

those impacts (Section III presents the estimated emission reductions associated with the 

final standards). This is primarily because currently available tools and methods to assess 

air toxics risk from mobile sources at the national scale are not adequate for extrapolation 

to incidence estimations or benefits assessment. The best suite of tools and methods 

currently available for assessment at the national scale are those used in the NationalScale Air Toxics Assessment (NATA). The EPA Science Advisory Board specifically 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

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commented in their review of the 1996 NATA that these tools were not yet ready for use 

in a national-scale benefits analysis, because they did not consider the full distribution of 

exposure and risk, or address sub-chronic health effects.571 While EPA has since 

improved these tools, there remain critical limitations for estimating incidence and 

assessing benefits of reducing mobile source air toxics. 

As part of the second prospective analysis of the benefits and costs of the Clean 

Air Act,572 EPA conducted a case study analysis of the estimated health effects associated 

with reducing exposure to benzene in Houston from implementation of the Clean Air Act. 

While reviewing the draft report, EPA’s Advisory Council on Clean Air Compliance 

Analysis concluded that “the challenges for assessing progress in health improvement as 

a result of reductions in emissions of hazardous air pollutants (HAPs) are daunting...due 

to a lack of exposure-response functions, uncertainties in emissions inventories and 

background levels, the difficulty of extrapolating risk estimates to low doses and the 

challenges of tracking health progress for diseases, such as cancer, that have long latency

periods.”573 EPA continues to work to address these limitations; however, we did not 

have the methods and tools available for national-scale application in time for the 

analysis of the final standards.574 

The reduction in air pollution emissions that will result from the final program 

also is projected to have “welfare” co-benefits in addition to human health benefits, 

including changes in visibility, materials damage, ecological effects from PM deposition, 

ecological effects from nitrogen and sulfur emissions, vegetation effects from ozone 

exposure, and climate effects.575 Despite our goal to quantify and monetize as many of 

the benefits as possible for the final rulemaking, the welfare co-benefits of the Tier 3 

 

571 Science Advisory Board. (2001). NATA – Evaluating the National-Scale Air Toxics Assessment for 

1996 – an SAB Advisory. http://www.epa.gov/ttn/atw/sab/sabrev.html.

572 U.S. Environmental Protection Agency (U.S. EPA). (2011). The Benefits and Costs of the Clean Air Act 

from 1990 to 2020. Office of Air and Radiation, Washington, DC. March. Available on the Internet at 

<http://www.epa.gov/air/sect812/feb11/fullreport.pdf>.

573 U.S. Environmental Protection Agency—Science Advisory Board (U.S. EPA-SAB). (2008). Benefits of 

Reducing Benzene Emissions in Houston, 1990–2020. EPA-COUNCIL-08-001. July. Available at 

<http://yosemite.epa.gov/sab/sabproduct.nsf/D4D7EC9DAEDA8A548525748600728A83/$File/EPACOUNCIL-08-001-unsigned.pdf>.

574 In April, 2009, EPA hosted a workshop on estimating the benefits or reducing hazardous air pollutants. 

This workshop built upon the work accomplished in the June 2000 Science Advisory Board/EPA 

Workshop on the Benefits of Reductions in Exposure to Hazardous Air Pollutants, which generated 

thoughtful discussion on approaches to estimating human health benefits from reductions in air toxics 

exposure, but no consensus was reached on methods that could be implemented in the near term for a broad 

selection of air toxics. Please visit http://epa.gov/air/toxicair/2009workshop.html for more information 

about the workshop and its associated materials.

575 We project that the Tier 3 vehicle and fuel standards will reduce nitrous oxide (N2O) and methane (CH4) 

emissions from vehicles. The reductions in these potent greenhouse gases will be offset to some degree by 

the increase in CO2 emissions from refineries. The combined impact is a net decrease on a CO2-equivalent 

basis and would yield a net benefit if these reductions were monetized.
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standards remain unquantified and non-monetized due to data, methodology, and 

resource limitations. As a result, the benefits quantified in this analysis are likely

underestimates of the total benefits attributable to the final program. We refer the reader 

to Chapter 6 of the PM NAAQS RIA for a complete discussion of these welfare cobenefits.576

We received many comments from the public and interested stakeholders, many

of which were supportive of the benefits analysis conducted in support of the rulemaking 

and some that were adverse. Several commenters (primarily associated with the fuels 

industry) were critical of a number of EPA assumptions and other aspects of the analysis.

As described more fully in the Summary and Analysis of Comments document 

that accompanies this rulemaking, EPA disagrees with the claims of these commenters. 

We base our analysis of the program’s impact on human health and the environment on 

peer-reviewed studies of air quality and human health effects.577,578 Our benefits methods 

are consistent with the RIA that accompanied the final revisions to the National Ambient 

Air Quality Standards (NAAQS) for Particulate Matter and the final ozone NAAQS. Our 

methods also undergo rigorous review by many independent expert panels, including the 

Science Advisory Board and the National Research Council. Our methods and 

assumptions reflect their guidance, review, and recommendations. As a result, we 

believe our analysis reflects the state of the science for health impacts and benefits 

assessment. 

The Agency also received many comments supportive of the benefits that the Tier 

3 standards will achieve. This includes broad support from many non-governmental 

institutions, state and local governments, and private citizens. 

B. Quantified Human Health Impacts

Table VIII-3 and Table VIII-4 present the core estimates of annual PM2.5 and 

ozone health impacts, respectively, in the 48 contiguous U.S. states associated with the 

final standards for 2030. For each endpoint presented in Table VIII-3 and Table VIII-4, 

we provide both the mean estimate and the 90 percent confidence interval. 

 

576 U.S. Environmental Protection Agency. (2012). Regulatory Impact Analysis for the Final Revisions to 

the National Ambient Air Quality Standards for Particulate Matter. Prepared by: Office of Air and 

Radiation, EPA-452/R-12-005. Retrieved August 14, 2013 at http://www.epa.gov/ttn/ecas/ria.html

577 U.S. Environmental Protection Agency. (2012). Regulatory Impact Analysis for the Final Revisions to 

the National Ambient Air Quality Standards for Particulate Matter. Prepared by: Office of Air and 

Radiation, EPA-452/R-12-005. Retrieved August 14, 2013 at http://www.epa.gov/ttn/ecas/ria.html

578 U.S. Environmental Protection Agency. (2008). Final Ozone NAAQS Regulatory Impact Analysis. 

Prepared by: Office of Air and Radiation, Office of Air Quality Planning and Standards. Retrieved March, 

26, 2009 at http://www.epa.gov/ttn/ecas/ria.html. EPA-HQ-OAR-2009-0472-0238
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Using EPA’s preferred estimates, based on the American Cancer Society (ACS) 

and Six-Cities studies and no threshold assumption in the model of mortality, we estimate 

that the final standards would result in between 660 and 1,500 cases of avoided PM2.5-

related premature mortalities annually in 2030. A sensitivity analysis was also conducted 

to understand the impact of alternative concentration response functions suggested by 

experts in the field. When the range of expert opinion is used, we estimate between 130 

and 2,200 fewer premature mortalities in 2030 (see Table 8.8 in the RIA that 

accompanies this action). For ozone-related premature mortality in 2030, we estimate a 

range of between 110 to 500 fewer premature mortalities. 

Table VIII-3 Estimated PM2.5-Related Health Impactsa

Health Effect 2030 Annual 

Reduction in 

Incidence

(5th% - 95th%ile)

Premature Mortality – Derived from epidemiology literatureb

 Adult, age 30+, ACS Cohort Study (Krewski et al., 2009)

 Adult, age 25+, Six-Cities Study (Lepeule et al., 2012)

 Infant, age <1 year (Woodruff et al., 1997)

660

(480 – 840)

1,500

(860 – 2,100)

Non-fatal myocardial infarction (adult, age 18 and over)

 Peters et al. (2001)

 Pooled estimate of 4 studies

790

(290 – 1,300)

85

(42 – 190)

Hospital admissions - respiratory (all ages)c,e 210

(-38 – 380)

Hospital admissions - cardiovascular (adults, age >18)d250

(130 – 440)

Emergency room visits for asthma (age 18 years and younger)e340

(-58 – 660)

Acute bronchitis, (children, age 8-12)e980

(-35 – 2,000)

Lower respiratory symptoms (children, age 7-14) 13,000

(6,000 – 19,000)

Upper respiratory symptoms (asthmatic children, age 9-18) 18,000

(5,600 – 30,000)

Asthma exacerbation (asthmatic children, age 6-18) 19,000

(2,300 – 37,000)

Work loss days 81,000

(70,000 – 91,000)

Minor restricted activity days (adults age 18-65) 480,000

(400,000 – 550,000)

a Incidence is rounded to two significant digits. Estimates represent incidence within the 48 contiguous 

United States. 

b PM-related adult mortality based upon the most recent American Cancer Society (ACS) Cohort Study 

(Krewski et al., 2009) and the most recent Six-Cities Study (Lepeule et al., 2012). Note that these are 
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Page 465 of 1039

two alternative estimates of adult mortality and should not be summed. PM-related infant mortality 

based upon a study by Woodruff, Grillo, and Schoendorf, (1997).579

c Respiratory hospital admissions for PM include admissions for chronic obstructive pulmonary disease 

(COPD), pneumonia and asthma.

d Cardiovascular hospital admissions for PM include total cardiovascular and subcategories for 

ischemic heart disease, dysrhythmias, and heart failure.

e The negative estimates at the 5th percentile confidence estimates for these morbidity endpoints 

reflect the statistical power of the study used to calculate these health impacts. These results do not 

suggest that reducing air pollution results in additional health impacts.

Table VIII-4 Estimated Ozone-Related Health Impactsa

Health Effect 2030 Annual Reduction 

in Incidence

(5th% - 95th%ile)

Premature Mortality, All agesb

Multi-City Analyses 

 Bell et al. (2004) – Non-accidental

 Huang et al. (2005) – Cardiopulmonary

 Schwartz (2005) – Non-accidental

Meta-analyses:

 Bell et al. (2005) – All cause

 Ito et al. (2005) – Non-accidental

 Levy et al. (2005) – All cause

110

(46 – 170)

160

(74 – 250)

170

(68 – 270)

350

(190 – 510)

490

(320 – 660)

500

(360 – 630)

Hospital admissions- respiratory causes (adult, 65 and 

older)c

740

(87 – 1,400)

Hospital admissions -respiratory causes (children, under 2) 310

(160 – 450)

Emergency room visit for asthma (all ages)d330

(-8 – 990)

Minor restricted activity days (adults, age 18-65) 600,000

(290,000 – 910,000)

School absence days 210,000

(92,000 – 300,000)

a

Incidence is rounded to two significant digits. Estimates represent incidence within the 48 

contiguous U.S. 

b Estimates of ozone-related premature mortality are based upon incidence estimates derived from 

several alternative studies: Bell et al. (2004); Huang et al. (2005); Schwartz (2005) ; Bell et al. (2005); 

Ito et al. (2005); Levy et al. (2005). The estimates of ozone-related premature mortality should 

therefore not be summed.

 

579 Woodruff, T.J., J. Grillo, and K.C. Schoendorf. (1997). The Relationship Between Selected Causes of 

Postneonatal Infant Mortality and Particulate Air Pollution in the United States. Environmental Health 

Perspectives 105(6):608-612.
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c Respiratory hospital admissions for ozone include admissions for all respiratory causes and 

subcategories for COPD and pneumonia. 

d The negative estimate at the 5th percentile confidence estimate for this morbidity endpoint reflects 

the statistical power of the study used to calculate this health impact. This result does not suggest that 

reducing air pollution results in additional health impacts.

C. Monetized Benefits

Table VIII-5 presents the estimated monetary value of changes in the incidence of 

ozone and PM2.5-related health effects. All monetized estimates are stated in 2011 

dollars. These estimates account for growth in real gross domestic product (GDP) per 

capita between the present and 2030. Our estimate of total monetized benefits in 2030 

for the program, using the ACS and Six-Cities PM mortality studies and the range of 

ozone mortality assumptions, is between $7.4 and $19 billion, assuming a 3 percent 

discount rate, or between $6.7 and $18 billion, assuming a 7 percent discount rate. This 

represents the health benefits of the Tier 3 program anticipated to occur annually when 

the program is fully implemented and most of the fleet turned over.

Table VIII-5 Estimated Monetary Value of Changes in Incidence of Health and 

Welfare Effects in 2030 (Millions of 2011$) a

HEALTH ENDPOINTS 2030

(5TH AND 95TH

PERCENTILE)

PM2.5-Related Health Effects

Premature Mortality – Derived 

from Epidemiology Studiesb,c

Adult, age 30+ - ACS study 

(Krewski et al., 2009)

 3% discount rate

 7% discount rate

$6,100

($910 - $14,000)

$5,500

($820 - $13,000)

Adult, age 25+ - Six-Cities study 

(Lepeule et al., 2012)

 3% discount rate

 7% discount rate

$14,000

($2,000 - $33,000)

$12,000

($1,800 - $30,000)

Infant Mortality, <1 year –

(Woodruff et al. 1997)

$13

($1.8 - $32)

Non-fatal acute myocardial infarctions 

 Peters et al., 2001

 3% discount rate

 7% discount rate

 Pooled estimate of 4 studies

 3% discount rate

 7% discount rate

$96

($21 - $230)

$93

($19 - $220)

$10

($2.6 - $27)

$10

($2.4 - $27)

Hospital admissions for respiratory causesd$5.9
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(-$1.6 - $11)

Hospital admissions for cardiovascular causes $9.9

($5.0 - $17)

Emergency room visits for asthmad$0.15

(-$0.02 - $0.29)

Acute bronchitis (children, age 8–12)d$0.49

(-$0.02 - $1.2)

Lower respiratory symptoms (children, 7–14) $0.27

($0.11 - $0.51)

Upper respiratory symptoms (asthma, 9–11) $0.62

($0.18 - $1.4)

Asthma exacerbations $1.1

($0.14 - $2.7)

Work loss days $12

($11 – $14)

Minor restricted-activity days (MRADs) $34

($20 - $49)

Ozone-Related Health Effects

Premature Mortality, All ages –

Derived from Multi-city analyses

Bell et al., 2004 $1,100

($150 - $2,800)

Huang et al., 2005 $1,600

($220 - $4,100)

Schwartz, 2005 $1,700

($220 - $4,400)

Premature Mortality, All ages –

Derived from Meta-analyses

Bell et al., 2005 $3,600

($510 - $8,800)

Ito et al., 2005 $5,000

($740 - $12,000

Levy et al., 2005 $5,100

($760 - $12,000)

Hospital admissions- respiratory causes (adult, 65 and older) $21

($2.5 - $39)

Hospital admissions- respiratory causes (children, under 2) $3.7

($1.9 - $5.4)

Emergency room visit for asthma (all ages) $0.14

(-$0.003 - $0.41)

Minor restricted activity days (adults, age 18-65) $43

($19 - $73)

School absence days $21

($9.3 - $31)

a Monetary benefits are rounded to two significant digits for ease of presentation and computation. PM and 

ozone benefits are nationwide. 

b Monetary benefits adjusted to account for growth in real GDP per capita between 1990 and the analysis 

year (2030).

c Valuation assumes discounting over the SAB recommended 20 year segmented lag structure. Results 

reflect the use of 3 percent and 7 percent discount rates consistent with EPA and OMB guidelines for 

preparing economic analyses.

d The negative estimate at the 5th percentile confidence estimate for this morbidity endpoint reflects the 

statistical power of the study used to calculate this health impact. This result does not suggest that reducing 

air pollution results in additional health impacts.
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D. What are the Limitations of the Benefits Analysis?

Every benefit-cost analysis examining the potential effects of a change in 

environmental protection requirements is limited to some extent by data gaps, limitations 

in model capabilities (such as geographic coverage), and uncertainties in the underlying 

scientific and economic studies used to configure the benefit and cost models. 

Limitations of the scientific literature often result in the inability to estimate quantitative 

changes in health and environmental effects, such as potential decreases in premature 

mortality associated with decreased exposure to carbon monoxide. Deficiencies in the 

economics literature often result in the inability to assign economic values even to those 

health and environmental outcomes which can be quantified. These general uncertainties 

in the underlying scientific and economics literature, which can lead to valuations that are 

higher or lower, are discussed in detail in the RIA and its supporting references. Key

uncertainties that have a bearing on the results of the benefit-cost analysis of the final 

standards include the following:

 The exclusion of potentially significant and unquantified benefit categories 

(such as health, odor, and ecological benefits of reduction in air toxics, ozone, 

and PM);

 Errors in measurement and projection for variables such as population growth;

 Uncertainties in the estimation of future year emissions inventories and air 

quality (including future year climate uncertainty);

 Uncertainty in the estimated relationships of health and welfare effects to 

changes in pollutant concentrations including the shape of the concentrationresponse function, the size of the effect estimates, and the relative toxicity of 

the many components of the PM mixture; 

 Uncertainties in exposure estimation; and

 Uncertainties associated with the effect of potential future actions to limit 

emissions.

As Table VIII-5 indicates, total benefit estimates are driven primarily by the 

reduction in premature mortalities each year. Some key assumptions underlying the 

premature mortality estimates include the following, which may also contribute to 

uncertainty:

 We assume that all fine particles, regardless of their chemical composition, 

are equally potent in causing premature mortality. This is an important 

assumption, because PM2.5 varies considerably in composition across sources, 

but the scientific evidence is not yet sufficient to allow differential effects 

estimates by particle type. The 2009 PM ISA, which was twice reviewed by
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EPA’s Science Advisory Board Clean Air Science Advisory Committee 

(SAB-CASAC), concluded that “many constituents of PM2.5 can be linked 

with multiple health effects, and the evidence is not yet sufficient to allow 

differentiation of those constituents or sources that are more closely related to 

specific outcomes.”580

 We assume that the health impact function for fine particles is log-linear 

without a threshold in this analysis. Thus, the estimates include health benefits 

from reducing fine particles in areas with varied concentrations of PM2.5, 

including both areas that do not meet the fine particle standard and those areas 

that are in attainment, down to the lowest modeled concentrations.

 We assume that there is a “cessation” lag between the change in PM 

exposures and the total realization of changes in mortality effects. 

Specifically, we assume that some of the incidences of premature mortality 

related to PM2.5 exposures occur in a distributed fashion over the 20 years 

following exposure based on the advice of EPA’s Science Advisory Board 

Health Effects Subcommittee (SAB-HES),581 which affects the valuation of 

mortality benefits at different discount rates.

 There is uncertainty in the magnitude of the association between ozone and 

premature mortality. The range of ozone benefits associated with the final 

standards is estimated based on the risk of several sources of ozone-related 

mortality effect estimates. In a report on the estimation of ozone-related 

premature mortality published by the National Research Council, a panel of 

experts and reviewers concluded that short-term exposure to ambient ozone is 

likely to contribute to premature deaths and that ozone-related mortality

should be included in estimates of the health benefits of reducing ozone 

exposure.582 

Despite the uncertainties described above, we believe this analysis provides a 

conservative estimate of the estimated criteria pollutant-related health and environmental 

benefits of the standards in future years because of the exclusion of potentially significant 

 

580 U.S. Environmental Protection Agency (U.S. EPA). 2009. Integrated Science Assessment for Particulate 

Matter (Final Report). EPA-600-R-08-139F. National Center for Environmental Assessment—RTP 

Division. December. Available on the Internet at 

<http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=216546>.

581 U.S. Environmental Protection Agency—Science Advisory Board (U.S. EPA-SAB). 2004. Advisory 

Council on Clean Air Compliance Analysis Response to Agency Request on Cessation Lag. EPACOUNCIL-LTR-05-001. December. Available on the Internet at 

<http://yosemite.epa.gov/sab/sabproduct.nsf/0/39F44B098DB49F3C85257170005293E0/$File/council_ltr_

05_001.pdf>.

582 National Research Council (NRC), (2008). Estimating Mortality Risk Reduction and Economic 

Benefits from Controlling Ozone Air Pollution. The National Academies Press: Washington, D.C.
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benefit categories that are not quantifiable at this time. Acknowledging benefits 

omissions and uncertainties, we present a best estimate of the total benefits based on our 

interpretation of the best available scientific literature and methods supported by EPA’s 

technical peer review panel, the Science Advisory Board’s Health Effects Subcommittee 

(SAB-HES). The National Academies of Science (NRC, 2002) has also reviewed EPA’s 

methodology for analyzing the health benefits of measures taken to reduce air pollution. 

EPA addressed many of these comments in the analysis of the final PM NAAQS.583,584 

This analysis incorporates this work to the extent possible. 

E. Illustrative Analysis of Estimated Monetized Impacts Associated with the Rule

in 2018

For illustrative purposes, this section presents the total estimated monetized 

benefits associated with the final standards in 2018. As presented in Section III.B, the 

emissions impacts of the final standards in 2018 are primarily due to the effects of sulfur 

on the existing (pre-Tier 3) fleet. 

Table VIII-6 presents total aggregate monetized benefits of the program in 2018. 

Monetized estimates are presented in 2011$. Our estimate of total monetized benefits 

associated with the final standards in 2018, using the ACS and Six-Cities PM mortality

studies and the range of ozone mortality assumptions, is between $2.1 and $5.6 billion, 

assuming a 3 percent discount rate, or between $1.9 and $5.3 billion, assuming a 7 

percent discount rate. For a more detailed presentation of the quantified and monetized 

impacts of the final standards in 2018, please refer to Chapter 8 of the RIA that 

accompanies this preamble.

 

583 National Research Council (NRC). (2002). Estimating the Public Health Benefits of Proposed Air 

Pollution Regulations. The National Academies Press: Washington, D.C.

584 U.S. Environmental Protection Agency. (2012). Regulatory Impact Analysis for the Final Revisions to 

the National Ambient Air Quality Standards for Particulate Matter. Prepared by: Office of Air and 

Radiation, EPA-452/R-12-005. Retrieved August 14, 2013 at http://www.epa.gov/ttn/ecas/ria.html
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Table VIII-6 Total Estimated Monetized Ozone and PM-related Benefits Associated 

with the Final Standards in 2018a

Total Ozone and PM Benefits (billions, 2011$) –

PM Mortality Derived from the ACS and Six-Cities Studies

3% Discount Rate 7% Discount Rate

Ozone 

Mortality 

Function

Reference Mean Total 

Benefits

Ozone 

Mortality 

Function

Reference Mean Total 

Benefits

Multi-city Bell et al., 

2004

$2.1 - $4.1 Multi-city Bell et al., 

2004

$1.9 - $3.7

Huang et al., 

2005

$2.3 - $4.2 Huang et al., 

2005

$2.1 - $3.9

Schwartz, 

2005

$2.3 - $4.3 Schwartz, 

2005

$2.1 - $3.9

Meta-analysis Bell et al., 

2005

$3.1 - $5.0 Meta-analysis Bell et al., 

2005

$2.9 - $4.7

Ito et al., 

2005

$3.6 - $5.6 Ito et al., 

2005

$3.4 - $5.2

Levy et al., 

2005

$3.6 - $5.6 Levy et al., 

2005

$3.5 - $5.3

Total Ozone and PM Benefits (billions, 2010$) –

PM Mortality Derived from Expert Elicitation (Lowest and Highest Estimate)

3% Discount Rate 7% Discount Rate

Ozone 

Mortality 

Function

Reference Mean Total 

Benefits

Ozone 

Mortality 

Function

Reference Mean Total 

Benefits

Multi-city Bell et al., 

2004

$0.81 - $5.8 Multi-city Bell et al., 

2004

$0.78 - $5.3

Huang et al., 

2005

$1.0 - $6.0 Huang et al., 

2005

$0.98 - $5.5

Schwartz, 

2005

$1.0 - $6.0 Schwartz, 

2005

$1.0 - $5.5

Meta-analysis Bell et al., 

2005

$1.8 - $6.8 Meta-analysis Bell et al., 

2005

$1.8 - $6.3

Ito et al., 

2005

$2.3 - $7.3 Ito et al., 

2005

$2.3 - $6.8

Levy et al., 

2005

$2.4 - $7.4 Levy et al., 

2005

$2.4 - $6.8

a Total includes estimated premature mortality-related and morbidity-related ozone and PM2.5 benefits. 

Range was developed by adding the estimate from the ozone premature mortality function to the estimate 

of PM2.5-related premature mortality derived from either the ACS study (Krewski et al., 2009) or the SixCities study (Lepeule et al., 2012) or the lowest and highest mortality estimate across the range derived 

from the expert elicitation. Range also reflects alternative estimates of non-fatal heart attacks avoided 

based on either Peters et al. (2001) or a pooled estimate of four studies.

IX. Alternatives Analysis

As described throughout this preamble, we have considered a number of 

regulatory alternatives in the development of this final rule, including alternatives related 

to timing and stringency of the standards, as well as alternative program design elements 
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(e.g., averaging, banking, and trading). This section summarizes alternatives we have 

considered for both vehicle emission and fuel standards. 

A. Vehicle Emission Standards

The federal vehicle emission standards we are adopting are the most stringent 

feasible considering anticipated developments in motor vehicle emissions control 

technology. Consideration of alternatives focused less on the level of the fleet-average 

and per-vehicle standards themselves and more on the phase-in schedule for the 

standards, which can have an important influence on the cost of the standards. Phase-in 

schedules directly impact costs depending on how they are aligned with other light-duty 

rules and product design cycles, especially those of the California LEV III criteria 

emissions program and the EPA greenhouse gas (GHG) rules. In addition, phase-in 

schedules can impact the cost of available resources, specifically design, development 

and testing resources within vehicle manufacturers and emission control suppliers.585 

As we considered options for the Tier 3 vehicle standards, one of the important 

factors we considered was the degree of harmonization that would result between Tier 3 

and the CARB LEV III program. As discussed earlier in this preamble, the auto 

manufacturing industry stressed throughout the development of the Tier 3 rule and in 

their comments on the proposed rule – both as individual companies and through their 

trade associations – the need for harmonization of the two programs as completely and as 

soon as possible. 

Another factor in our consideration of program options has been how the timing 

of the Tier 3 program aligns with the federal light-duty vehicle GHG rules. We believe 

that both programs will be more efficient and less costly if manufacturers have greater 

ability to coordinate their product planning to respond to the various regulatory

requirements they face.

For these reasons, we have focused on program alternatives that generally achieve 

close harmony with the California programs in the earliest appropriate time frame, and on 

a schedule matching those of the GHG rules as much as possible. The following 

paragraphs describe the major alternatives we have considered.

1. Shorter NMOG+NOX Standard Phase-in

We originally considered requiring full implementation of the NMOG+NOX final 

fleet average standard by MY 2022. However, we determined that this would have 

 

585 We note that the Tier 3 program includes additional phase-in flexibility through the alternative phase-in 

schedules for light-duty exhaust emissions standards, heavy-duty exhaust emissions standards, and lightand heavy-duty evaporative emissions standards. 
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disrupted the manufacturer’s normal product design cycles,586 and it would not have 

allowed manufacturers to use consistent product design cycles for both the Tier 3 

standards and the 2017 LD GHG standards, which reach full implementation in MY 

2025. We are adopting a phase-in schedule that gradually increases the stringency of the 

standards until MY 2025, as with the GHG program, in order to allow vehicle 

manufacturers to better integrate the compliance with Tier 3 into their product design 

cycles as well as to take advantage of additional learning to reduce costs. We believe this 

implementation schedule for the Tier 3 NMOG+NOX standards allows us to achieve the 

environmental objectives of the program without imposing unnecessary costs and burden 

on the industry.

2. NMOG+NOX Standards Phase-in and Early Tier 3 Credits

The key agency goals in designing the structure of the Tier 3 program are to 

facilitate the step-down in fleet average stringency in the initial model years and to create 

a program that is of equivalent stringency and aligned with LEV III as early as possible. 

We considered allowing manufacturers to generate early credits against the current Tier 2 

Bin 5 fleet average and to use generated early credits without limitation for the first five 

years of the Tier 3 program. CARB, along with some vehicle manufacturers, noted that if 

a manufacturer were to substantially over-comply with the Tier 2 Bin 5 fleet average, 

these early credits might delay achievement of the Tier 3 emission levels and also delay

harmonization between the Tier 3 and LEV III programs for several years. Based on the 

fact that manufacturers are selling many vehicles today that are already cleaner than the 

existing Tier 2 Bin 5 fleet average, we believe that there is a strong potential for them to 

generate an excessive amount of credits. Also, most manufacturers will already have 

begun to sell vehicles that meet the LEV III standards (and thus the Tier 3 standards). 

The use of such a “windfall” of credits would likely result in a substantial delay in 

achieving alignment between the LEV III and Tier 3 programs. 

To avoid this potential misalignment, we are finalizing as proposed a provision 

that any early credits generated be capped starting in MY 2018 at the number of a 

manufacturer’s LEV III credits, but adjusted by the ratio of California and other LEV III 

sales nationwide. (See Section IV.A.7.a for more detail on these early credit provisions.) 

This approach balances the need for meaningful transition flexibility to avoid 

unnecessary costs, while still ensuring expeditious harmonization with LEV III and 

achievement of the environmental benefits of the Tier 3 standards.

3. NMOG+NOX Standards

We believe that the fleet-average NMOG+NOX standards that we are finalizing 

reflect the greatest degree of emission reduction achievable considering cost, 

 

586 A light-duty vehicle product design cycle is the number of years between major redesigns of a vehicle. 

Typically, major redesigns are completed every 5 to 6 years.
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developments in technology, and gasoline sulfur levels as required by this rule. We also 

believe the implementation schedule for the NMOG+ NOX standards is as short as 

practicable, as explained above. We believe that more stringent or less stringent 

standards are not justified based on the information currently available, including 

comments received. Therefore, and consistent with our goal of harmonizing the Tier 3 

program with LEV III as much as possible, we are finalizing the declining FTP and SFTP 

NMOG+NOX standards and phase-in schedules as proposed, as discussed in Section 

IV.A.3 and IV.A.4 above. 

4. PM Standards

The FTP and SFTP (US06) PM standards that we are adopting are the most 

stringent technically feasible standards within their implementation timeframe and meet 

the EPA goal of bringing all vehicles to the FTP and US06 PM emission levels 

demonstrated by most vehicles today. 

We considered adopting for Tier 3 the 1 mg/mi FTP PM standard that the LEV III 

program will begin phasing-in in MY 2025. However, as explained in the proposal and 

in Section IV.A.3.b above, and upon further review of current test procedures and the 

public comments, we concluded that 3 mg/mi is the most stringent technologically

feasible FTP PM standard. We will continue to work closely with CARB in this area. 

Specifically, our agencies will continue our parallel evaluations of how improved 

gravimetric PM measurement methods can reduce PM mass measurement variability at 

very low PM levels, and how this relates to the evolving technological capabilities of 

automakers to reach very low PM levels with sufficient compliance margins. 

As discussed in Section IV.A.4, we are finalizing numerically lower US06 

standards than those we proposed. More recent test data shows that the levels of the final 

US06 standards better meet EPA’s goal of capping US06 PM emissions at levels already

being demonstrated by most vehicles in the current light-duty fleet. We proposed a 10 

mg/mi US06 PM standard for cars, and 20 mg/mi for trucks. Like the FTP PM standards, 

the US06 PM standards are per-vehicle caps and not fleet averages. The comments we 

received ranged from suggesting a numerically lower standard to maintaining the 

standards as proposed. CARB and other stakeholders recommended a standard of 4 

mg/mi, and the International Council on Clean Transportation recommended that the 

standards be no higher than 6 mg/mi. The Alliance and Global Automakers supported 

the proposed standards. We considered all of the comments suggesting various levels for 

these standards, and we are finalizing standards of 10 mg/mi through MY 2021 and of 6 

mg/mi for 2022 and later model years, for both lighter and heavier vehicles, because they

reflect the current US06 PM performance of most vehicles. We believe these standards 

will address current poor performing vehicles and ensure that future vehicles with future 

technologies will perform, at a minimum, at or near the level of PM emissions that is 

being demonstrated by current vehicles.
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Because the final standards maintain the same stringency relative to emission 

levels achieved currently, as we describe our goal for these standards in the proposal, 

there is no difference in the projected costs and benefits associated with the proposed and 

final US06 PM standard levels. The costs associated with meeting the final PM standards

are driven by the vehicle performance over the FTP. That is, the 3 mg/mi FTP standard 

is the primary controlling factor in a vehicle’s overall PM performance and manufacturer 

compliance strategies. The US06 PM standard is intended to supplement the FTP PM 

standard in that any additional level of PM control required to meet the US06 PM 

standard is expected to be accomplished through calibration and not through the use of 

additional hardware. 

5. Higher Ethanol Content of Emissions Test Fuel 

We proposed and considered a change in the required ethanol content of 

emissions test fuel, from the current zero percent (E0) specification to a 15 percent 

ethanol (E15) specification. However, as discussed in Section IV.F above, the market 

fuel shift toward higher ethanol content has not materialized, and we are finalizing E10 as 

the Tier 3 gasoline test fuel to better match in-use fuels expected in the implementation 

timeframe of the Tier 3 standards. The adoption of E10 in lieu of E15 not only creates a 

federal test fuel that more closely reflects the ethanol content of in-use fuel currently and 

in the foreseeable future, but also more closely aligns with California’s LEV III test fuel. 

B. Fuel Sulfur Standards

1. Annual Average Sulfur Standard

As explained in Section V.B., we believe that a 10 ppm annual average standard 

is required to enable the vehicle fleet to meet the final Tier 3 standards and appropriately 

balances feasibility with costs. Other countries and California have also reduced the 

sulfur content of their gasoline; California’s gasoline is already meeting our proposed 10 

ppm average sulfur level, and Europe and Japan have a cap on the sulfur content of 

gasoline at 10 ppm. During the development of the proposed rule, we considered 

imposing a 10 ppm cap (i.e., no averaging, banking and trading), similar to the standard 

in Europe and Japan, as well as an average standard lower than 10 ppm average, because 

vehicle emission performance improves as sulfur is reduced.

However, by allowing averaging to meet 10 ppm, we believe that the most 

challenged refiners would be able to avoid what could be cost-prohibitive investments, 

while still meeting 10 ppm across the fuel pool. As discussed in Section VII.B., we 

estimate that allowing averaging would reduce nationwide control costs by nearly 26 

percent, and would still be sufficient to enable vehicles to meet the proposed Tier 3 

standards.
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We also considered an even lower sulfur standard of 5 ppm. Based upon the 

results of our test programs and associated modeling, a sulfur standard of 5 ppm could 

reduce VOC+NOX emissions from the existing fleet by an additional 65,000 tons in 2018.

However, we believe a 5 ppm standard would significantly increase both capital 

and operating costs. Such a standard would require: (1) more severe treatment of FCC 

gasoline; (2) treatment of additional (non-FCC) gasoline blendstocks; (3) essentially all 

refineries to reduce sulfur to 5 ppm, thereby eliminating much of the benefit of the ABT 

provisions; and potentially (4) more overcapacity and storage for reprocessing offspecification product. A 5 ppm standard would also warrant consideration of controlling 

the contribution to gasoline sulfur from gasoline additives, transmix, ethanol denaturants, 

and contamination in the distribution system.

In our analysis of the 10 ppm average standard and refineries that might reduce 

sulfur to 5 ppm in order to generate credits, we estimated that the sulfur control costs to 

achieve 5 ppm would be about twice that for our final 10 ppm standard. This is 60 

percent higher on a cost per ppm-gallon basis. The much higher cost is because a 5 ppm 

standard eliminates the practical ability for refineries to trade credits. That is, there 

would not be enough refineries overcomplying to generate credits and support a viable 

trading program. As a result, it could become prohibitively expensive for the more 

challenged refineries to comply, creating potential financial hardship situations. Because 

the costs and other economic impacts rise dramatically as sulfur is reduced below 10 

ppm, we believe that a 10 ppm sulfur standard is the most stringent feasible standard 

considering technology and cost.

Table IX-1 below summarizes the various alternative gasoline sulfur programs 

that we assessed and our estimated costs for those alternative programs. 

Table IX-1. Summary of Costs for Alternative Fuel Programs

Sulfur Level Credit Trading Per-gallon 

Cost (c/gal)

Capital Cost 

($MM)

Final Rule Case 10 Nationwide 0.65 2025

NPRM Case 10 Intra-company

Only

0.75 2195

No ABT Case 10 None 0.87 2990

Stringent Case 5 None 1.27 3805

Table IX-1 demonstrates that the ABT program has a profound impact on the cost 

of sulfur control. The estimated per-gallon cost and the capital costs for the case without 

an ABT program are 35 percent and 47 percent higher, respectively, than the final rule 

case which assumes nationwide credit trading. The stringent sulfur control case, which 

modeled a 5 ppm average standard and assumes no ABT program, is estimated to cost 

about twice that of the final rule case. The final rule case, which provides a very flexible 
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ABT program, achieves a 10 ppm average sulfur standard at the lowest cost and therefore 

is the most cost-effective of the various options that we studied. 

Additionally, as discussed in Sections IV.A and V.B a standard above 10 ppm 

would not be sufficiently low to meet the Tier 3 emissions standards. The feasibility of 

the 30 mg/mi NMOG+NOx fleet average depends on exhaust catalyst systems that 

require gasoline with average sulfur levels of 10 ppm or less. Further, annual average 

sulfur levels greater than 10 ppm would significantly impair the emission control 

technology that we expect will be used to meet the Tier 3 standards and to ensure in-use 

compliance over a vehicle’s useful life. This is particularly a concern for some larger 

vehicles that will need to reduce NOx to near-zero levels, due to greater difficulty in 

reducing cold-start NMOG, in order to meet a combined NMOG+NOx standard. As 

discussed in Section IV.A.6, increasing gasoline sulfur to 20 or 30 ppm would make it 

impossible for vehicle manufacturers to meet the Tier 3 standards. Achieving Tier 3 

standards would require offsetting the resultant higher emissions, but EPA is not aware of 

existing or developing technology that could address these higher emissions when taking 

into consideration the entire vehicle fleet.

Thus, we believe that a standard of 10 ppm is appropriate. When combined with 

the advances in emissions control technologies, a 10 ppm average sulfur standard is 

sufficient to allow vehicles meet the Tier 3 emissions standards at the lowest cost.

2. Refinery Gate Sulfur Cap

In addition to lower average sulfur standards, we also considered lowering the 

per-gallon cap standards. As discussed in Section V.C, we are maintaining the current 

per-gallon caps of 80 ppm at the refinery gate and 95 ppm downstream. We co-proposed 

refinery gate per-gallon cap standards of 50 ppm and 80 ppm (with downstream caps of 

65 and 95, respectively), and we requested comment on a refinery gate cap of 20 ppm. 

In assessing the potential of a lower refinery gate cap of 50 ppm, we found that it 

would directionally increase the costs of the Tier 3 program. Our analysis shows that a 

50 ppm cap would increase the cost of the Tier 3 gasoline sulfur standards by

approximately 10 percent (see RIA Chapter 5). A cap at this level would result in higher 

capital costs for a number of refiners due to the decreased ability to handle off-spec 

product with a lower refinery gate cap. The need for installation of additional tankage 

and/or increased refinery processing capability would also be greater, as refiners must 

ensure that they can continue to produce saleable product and meet demand in the event 

of an upset or an off-spec batch of fuel.

Additionally, the more stringent cap would unlikely provide significant additional 

emission benefits nationwide. As discussed previously in Sections III through V, the 

emissions benefits associated with the Tier 3 program are mainly associated with the 

reduction in the average sulfur content of gasoline from 30 to 10 ppm, since vehicle 

emissions are proportional to the sulfur content of the fuel; changes in the cap would not 
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affect this. We anticipate that in most (if not all) cases refineries will make operational 

changes and/or investments in order to reduce their credit burden and reduce their 

compliance costs; thus, we anticipate that most refineries, including those using credits, 

will still average less than 20 or 30 ppm in their physical gasoline production. While 

there will certainly be some variations above and below 10 ppm (just as there are today

relative to the 30 ppm standard under the current Tier 2 program), it is not possible for us 

to predict them in a way that we could quantify the associated emissions and air quality

impacts. As a result, we cannot currently estimate the potential benefits of a 50 ppm cap. 

However, during the implementation of the program we will be monitoring in-use sulfur 

levels and further evaluating in-use sulfur levels and their impact on vehicle emissions. 

This will provide us additional information with which to evaluate the potential benefits 

of a lower sulfur cap, if warranted. 

C. Program Start Date

We are finalizing the Tier 3 vehicle emissions and fuel standards with a 2017 start 

date, considering the vehicle and its fuel together as an integrated system. As described 

in Section IX.A.1 and 2, we considered different phase-ins for the vehicle program. We 

have also considered the comments requesting additional lead time for the fuel program. 

As discussed in Section V.L.3, we believe that the lead time provided is sufficient to meet 

a January 1, 2017, start date for the fuel sulfur standard, especially coupled with the 

flexibilities being offered as part of the program and the fact that only a few refineries 

will need to install grassroots equipment to meet the Tier 3 standards. As discussed in 

Section V.D, we did consider and are finalizing, in response to comments, a provision 

allowing refiners to carry over credits from Tier 2. 

Given that the lead time and associated programmatic flexibility we are finalizing 

is sufficient to allow industry to readily comply; we do not expect that a delay in the start 

date of the fuel standards would change the cost of compliance; any further delay in the 

program start date would simply delay the actions to comply. Furthermore, delaying the 

start of the program would forego significant emissions, air quality, and health benefits. 

Sections III and VIII describe the impacts of the Tier 3 standards in the year 2018. The 

majority of these impacts result from the effects of the fuel sulfur standard on the existing 

fleet, because there will be limited penetration of Tier 3 vehicles in 2018, and even those 

vehicles will not yet be meeting fully phased-in standards. Thus, the 2018 estimates of 

emission reductions, air quality improvements, and health benefits are an approximation 

of the benefits that would be foregone for each year that the program is delayed. Because 

we believe the start of the Tier 3 program is feasible and appropriate, and its delay would 

forego significant benefits, we are finalizing, as proposed, fuel sulfur standards that take 

effect January 1, 2017.
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X. Economic Impact Analysis

A. Introduction

The rule will affect two sectors directly: vehicle manufacturing and petroleum 

refining. For these two regulated sectors, the economic impact analysis discusses the 

market impacts from the rule: changes in price and quantity sold. In addition, although 

analysis of employment impacts is not part of a benefit-cost analysis (except to the extent 

that labor costs contribute to costs), employment impacts of federal rules are of particular 

concern in the current economic climate of sizeable unemployment. Executive Order 

13563, “Improving Regulation and Regulatory Review” (January 18, 2011), states, “Our 

regulatory system must protect public health, welfare, safety, and our environment while 

promoting economic growth, innovation, competitiveness, and job creation” (emphasis 

added). For this reason, we are examining the effects of this rule on employment in the 

regulated sectors.

Some commenters suggest that the overall effects of Tier 3 on the economy are 

likely to be positive, because the standards encourage innovation and reduce emissions. 

In addition, they suggest that Tier 3 will lead to greater employment to develop the 

emissions control technologies and to upgrade refineries. As discussed further below, 

other commenters suggest negative impacts, especially due to the fuel standards. The 

Motor and Equipment Manufacturers Association asks that the regulations “be based on 

sound science and data and balance the public interest objectives with economic realities 

of manufacturers.” EPA has used the best available information in developing these 

standards (including the use of peer reviewed literature, peer reviewed models, public 

comments received, etc.), and has documented its final estimates of the economic impacts 

from these standards in the RIA. 

B. Vehicle Sales Impacts

This rule takes effect from MY 2017-2025. In the intervening years, it is possible 

that the assumptions underlying a quantitative analysis, as well as market conditions, 

might change. For this reason, we present a qualitative discussion of the effects on 

vehicle sales of the standards at the aggregate market level. Vehicle manufacturers are 

expected to comply with the standards primarily through technological changes to 

vehicles. These changes to vehicle design and manufacturing are expected to increase 

manufacturers’ costs of vehicle production. 

Section VII.A estimates the increase in vehicle costs due to the standards. These 

costs differ across years and range from $46 to $65 for cars, $73 to $88 for trucks and 

$33 to $75 for Class 2b/3 vehicles (see Section VII.A). These costs are small relative to 

the cost of a vehicle. In a fully competitive industry, these costs would be entirely passed 

through to consumers. However in an oligopolistic industry such as the automotive 

sector, these increases in cost may not fully pass through to the purchase price, and the 

consumers may face an increase in price that is less than the increased manufacturers’ 
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costs of vehicle production.587 We do not quantify the expected level of cost passthrough or the ultimate vehicle price increase consumers are expected to face, apart from 

noting that prices are expected to increase by an amount up to the increase in 

manufacturers’ costs.

This increase in price is expected to lower the quantity of vehicles sold. Given 

that we expect that vehicle prices will not change by more than the cost increase, we 

expect that the decrease in vehicle sales will be negligible. 

The effect of this rule on the use and scrappage of older vehicles is related to its

effects on new vehicle prices and the total sales of new vehicles. The increase in price is 

likely to cause the “turnover” of the vehicle fleet (i.e., the retirement of used vehicles and 

their replacement by new models) to slow slightly, thus reducing the anticipated effect of 

the rule on fleet-wide emissions. Because we do not estimate the effect of the rule on 

new vehicle price changes nor do we have a good estimate of the effect of new vehicle 

price changes on vehicle turnover, we have not attempted to estimate explicitly the 

effects of the rule on scrappage of older vehicles and the turnover of the vehicle fleet.

Commenters note that the incentives to go beyond the 8-year/80,000-mile 

warranty could improve vehicle reliability and lower costs, in addition to improving air 

quality. Other commenters suggest that harmonizing standards across the whole U.S. 

will benefit the economy. EPA agrees that harmonized standards will simplify

manufacturing and marketing decisions for automakers. The Manufacturers of Emission 

Controls Association points out that many SULEV- and PZEV-compliant vehicles have 

already been sold in the U.S. Commenters did not raise other concerns with the 

qualitative vehicle sales analysis. 

C. Impacts on Petroleum Refinery Sector Production

The key change for refiners from the standards is more stringent sulfur 

requirements. This change to fuels is expected to increase manufacturers’ costs of 

gasoline production by about 0.65 cents per gallon (see Section VII.B).

Some commenters raise concerns about the economic burdens to refineries and to 

consumers who must buy more expensive gasoline, in part based on estimates of the costs 

of the standards as high as 6-9 cents per gallon. As discussed in Section VII.B of this 

preamble, EPA has considered the costs to refineries and has estimated that the additional 

cost of gasoline will be about 0.65 cents per gallon. Though some refineries may face 

 

587 See, for instance, Gron, A., and Swenson, D. (2000), Cost Pass-Through in the U.S. Automobile Market. 

Review of Economics and Statistics 82, 316-324 (Docket EPA-HQ-OAR-2011-0135-0056), who found 

significantly less than full-cost pass-through using data from 1984-1994. Using full-cost pass-through 

overstates costs and thus contributes to lower vehicle sales than using a lower estimate. To the extent that 

the auto industry has become more competitive over time, full-cost pass-through may be more appropriate 

than a result based on this older study.
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costs of up to 2.1 cents per gallon, and one refinery up to 2.8 cents per gallon, most will 

face much lower costs, as the averaging, banking, and trading provisions of the standards 

significantly ease the challenge of refineries to meet the standards. 

In a perfectly competitive industry, this cost would be passed along completely to 

consumers. In an imperfectly competitive industry, as noted above, full cost passthrough is not necessary: firms may choose to reduce impacts on sales by not passing 

along full costs. In 2004, the Federal Trade Commission reported that “concentration for 

most levels of the petroleum industry has remained low to moderate.”588 Thus the 

assumption of competitive markets has some foundation in this industry. We estimate 

that the price increase that consumers are likely to face should be positive and up to the 

increase in manufacturers’ costs of gasoline production.

The Emissions Control Technology Association (ECTA) and Northeast States for 

Coordinated Air Use Management (NESCAUM) note that previous Tier 2 standards, 

which required greater reductions in absolute magnitude, do not appear to have had 

measurable adverse impacts on refineries. ECTA cites a study by Navigant Economics 

that found no measurable impact on gasoline price from Tier 2. NESCAUM notes that 

refineries used a number of technologies and facility improvements to achieve the 

standards in a cost-effective manner, and notes that the North American refining industry

is making significant new investments in response to favorable long-term conditions. 

Small increases in gasoline price due to standards may be very difficult to identify, 

because of the natural volatility of gasoline prices. 

The effect of higher gasoline prices on gasoline sales is expected to be different 

over the short and long term. In the long run, in response to the increase in fuel costs, 

consumers can more easily change their driving habits, including where they live or what 

vehicles they use. Because of this, we expect that gasoline sales will decrease more in 

the long run compared to the short run as a result of the price increase due to the rule. 

However, because manufacturers’ costs are expected to increase less than one cent per 

gallon, we expect that the decrease in gasoline sales will be negligible over all time 

horizons. 

D. Employment Impacts

This section discusses changes in employment due to the rule. We focus on the 

auto manufacturing sector and the refinery sector because they are directly regulated, and 

because they are likely to bear a substantial share of changes in employment due to this 

rule. We partially quantify impacts in the auto sector, providing a mix of qualitative and 

 

588 Federal Trade Commission, Bureau of Economics. (2004). The Petroleum Industry: Mergers, 

Structural Change, and Antitrust Enforcement. Retrieved August 16, 2011from Federal Trade Commission 

website: http://www.ftc.gov/os/2004/08/040813mergersinpetrolberpt.pdf (Docket EPA-HQ-OAR-2011-

0135-0055).
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quantitative discussion, following the methods used in the Final Rulemaking for 2017–

2025 Model Year Light-Duty Vehicle Greenhouse Gas Emissions and Corporate Average 

Fuel Economy Standards.589 For the refinery sector we provide a qualitative analysis. 

We also include discussion of effects on the motor vehicle parts manufacturing sector 

because the auto manufacturing sector can either produce parts internally or buy them 

from an external supplier, and we do not have estimates of the likely breakdown of effort 

between the two sectors. For the same reasons, we discuss effects on producers of 

equipment that refiners will use to comply with the standards.

Chevron Products Company states that we did not consider the economic context 

of the time when discussing our impacts. As we stated in the NPRM, we recognize the 

importance of context. When the economy is at full employment, an environmental 

regulation is unlikely to have much impact on net overall U.S. employment; instead, 

labor would primarily be shifted from one sector to another. These shifts in employment 

impose an opportunity cost on society, approximated by the wages of the employees, as 

regulation diverts workers from other activities in the economy. In this situation, any

effects on net employment are likely to be transitory as workers change jobs (e.g., some 

workers may need to be retrained or require time to search for new jobs, while shortages 

in some sectors or regions could bid up wages to attract workers). 

On the other hand, if a regulation comes into effect during a period of high 

unemployment, a change in labor demand due to regulation may affect net overall U.S. 

employment because the labor market is not in equilibrium. Schmalansee and Stavins 

point out that net positive employment effects are possible in the near term when the 

economy is at less than full employment due to the potential hiring of idle labor resources 

by the regulated sector to meet new requirements (e.g., to install new equipment) and 

new economic activity in sectors related to the regulated sector.590 In the longer run, the 

net effect on employment is more difficult to predict and will depend on the way in which 

the related industries respond to the regulatory requirements. As Schmalansee and 

Stavins note, it is possible that the magnitude of the effect on employment could vary

over time, region, and sector, and positive effects on employment in some regions or 

sectors could be offset by negative effects in other regions or sectors. For this reason, 

they urge caution in reporting partial employment effects since it can “paint an inaccurate 

picture of net employment impacts if not placed in the broader economic context.”

A number of commenters (including unions, environmentalists, investor 

organizations, Medical Advocates for Health Air, NESCAUM, and the National 

Association of Clean Air Agencies) argue that the standards will increase employment, 

by stimulating auto companies and refiners to invest in pollution abatement equipment. 

As will be discussed further below, EPA agrees that the standards are likely to lead to 

 

589 77 FR 62623 (October 15, 2012).

590 Schmalensee, R., & Stavins, R. (2011). A Guide to Economic and Policy Analysis of EPA’s Transport 

Rule” White paper commissioned by Excelon Corporation (Docket EPA-HQ-OAR-2011-0135-0054).
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more employment to provide abatement equipment, but employment due to production 

may also be reduced (although by very small amounts) due to incrementally higher prices 

for vehicles and fuel; we expect the net impact on employment in the regulated sectors to 

be small. 

Chevron Products Company states that we do not account for the hardship on 

local and regional economies due to the increase in refinery costs. Because we do not 

consider employment impacts to be large, even at local and regional scale, we do not 

expect large impacts on the economies at that scale.

ECTA argues that job impacts will be not only positive in the auto and auto parts 

sectors, but substantially more positive than EPA states, based on Regional Input-Output 

Modeling System (RIMS) multipliers that find increases of 5.9 jobs for every $1 million 

investment in new auto parts. Multiplier impacts trace the entire chain of job impacts 

associated with an expenditure, including factors such as changes in employment in retail 

establishments due to changes in workers in the auto sector. Because the expenditures 

will occur when unemployment is still high, ECTA argues, it is important to consider the 

multiplier effects of the expenditures that are embedded in the RIMS multipliers. As 

discussed above, the multiplier impacts of expenditures depend heavily on the state of the 

macroeconomy. Because of uncertainty over the state of the economy when the 

increased expenditures will occur, EPA has not quantified the multiplier impacts due to 

changes in employment associated with these standards. As discussed again below, some 

expenditures, perhaps especially in the refinery sector, will occur before the standards 

take effect, to get the manufacturing processes in place to meet the standards. These 

near-term expenditures may have some multiplier effects, because they are more likely to 

have their impacts during the current period of above-average unemployment. In 

contrast, the ongoing costs of complying with the standards, which contribute most 

directly to price increases, are likely to come in future years, when it is expected that 

unemployment rates will be lower.

The Mercatus Center at George Mason University recommended that we 

“acknowledge that both jobs gained and jobs destroyed are costs of the proposed 

regulation. Ideally, compliance jobs should be minimized, not viewed as a benefit of a 

regulation.” This assertion is confusing, in that it implies that any effect on employment, 

positive or negative, is costly. Marathon Petroleum Company and the American 

Petroleum Institute with the Association of Fuel and Petroleum Manufacturers argue that 

employment impacts should not be counted as benefits. Our analysis of the employment 

impacts of the standards is intended to identify additional ways that these standards will 

affect the public. Employment clearly provides benefits to the people who are employed, 

and reducing unemployment is considered a desirable outcome in times of high 

unemployment. EPA disagrees that minimizing compliance jobs should be an 

independent objective of this rulemaking. The objective of the program is to improve air 
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quality through reductions in vehicle emissions; we provide information concerning 

employment impacts as part of our overall analysis of economic impacts from the rule.591

The Mercatus Center also requests that we consider the long-term effects of 

unemployment on workers who may lose jobs, and that we acknowledge that those who 

lose jobs may not be the same people who gain jobs. We recognize there are costs to 

workers who shift from one job to another,592 but we also note, as discussed further 

below, that we expect very small employment impacts from the standards.

After reviewing these comments, we conclude they have not identified any

specific reason to depart from the approach to employment analysis that was used in the 

NPRM, though we here use a slightly modified theoretical framework. In the NPRM, we 

followed the theoretical structure in a study by Morgenstern, Pizer, and Shih (2002)593 of 

the impacts of regulation in employment in the regulated sectors. We here shift to a very

similar framework by Berman and Bui.594 RIA Chapter 9.1 provides additional 

background on this framework. In Berman and Bui’s (2001, p. 274-75) theoretical 

model, the change in a firm’s labor demand arising from a change in regulation is 

decomposed into two main components: output and substitution effects.595

 The output effect describes how, if labor-intensity of production is held constant, 

a decrease in output generally leads to a decrease in labor demand. However, as 

noted by Berman and Bui, although it is often assumed that regulation increases 

marginal cost, and thereby reduces output, it need not be the case. A regulation 

could induce a firm to upgrade to less polluting, and more efficient equipment that 

lowers marginal production costs, for example. In such a case, output could 

theoretically increase. 

 

591 We note that employment shows up in the benefit-cost analysis through labor costs, which are included 

in the costs of achieving the standards; any increases in employment are part of the increased expenditures 

due to the standards, and decreases in employment reduce expenditures.

592 E.g., Jacobson, Louis S., Robert J. LaLonde, and Daniel G. Sullivan, “Earnings Losses of Displaced 

Workers.” American Economic Review 83(4) (1993): 685-709 (Docket EPA-HQ-OAR-2011-0135).

593 Morgenstern, R., Pizer, W., & Shih, J. (2002). Jobs Versus the Environment: An Industry-Level 

Perspective. Journal of Environmental Economics and Management 43, 412-436 (Docket EPA-HQ-OAR2011-0135-0057).

594 Berman, E. and L. T. M. Bui (2001). “Environmental Regulation and Labor Demand: Evidence from the 

South Coast Air Basin.” Journal of Public Economics 79(2): 265-295 (Docket EPA-HQ-OAR-2011-

0135).

595 The authors also discuss a third component, the impact of regulation on factor prices, but conclude that 

this effect is unlikely to be important for large competitive factor markets, such as labor and capital. 

Morgenstern, Pizer and Shih (2002) use a very similar model, but they break the employment effect into 

three parts: 1) the demand effect; 2) the cost effect; and 3) the factor-shift effect. See Morgenstern, Richard 

D., William A. Pizer, and Jhih-Shyang Shih. “Jobs Versus the Environment: An Industry-Level 

Perspective.” Journal of Environmental Economics and Management 43 (2002): 412-436 (Docket EPAHQ-OAR-2011-0135-0057).
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 The substitution effect describes how, holding output constant, regulation affects the 

labor-intensity of production. Although increased environmental regulation generally 

results in higher utilization of production factors such as pollution control equipment and 

energy to operate that equipment, the resulting impact on labor demand is ambiguous. 

For example, equipment inspection requirements, specialized waste handling, or pollution 

technologies that are added to the production process may affect the number of workers 

necessary to produce a unit of output. Berman and Bui (2001) model the substitution 

effect as the effect of regulation on pollution control equipment and expenditures that are 

required by the regulation and the corresponding change in labor-intensity of production. 

In summary, as the output and substitution effects may be both positive, both 

negative or some combination, standard neoclassical theory alone does not point to a 

definitive net effect of regulation on labor demand at regulated firms.

1. Employment Impacts in the Auto Sector

Following the Berman and Bui (2001) framework, we consider two effects for the 

auto sector: the output effect and the substitution effect.

a. The Output Effect

The output effect depends on the effects of this rule on vehicle sales. If vehicle 

sales decrease, employment associated with these activities will decrease. As discussed 

in Section X.B, we do not make a quantitative estimate on the effect of the rule on 

vehicle sales but we note that the decrease in vehicle sales is expected to be negligible. 

Thus we expect any decrease in employment in the auto sector through the output effect 

to be small as well.

b. The Substitution Effect

The output effect, above, measures the effect due to new vehicle sales only. The 

substitution effect measures the impacts due to the changes in technologies needed for 

vehicles to meet the standards, separate from the effect on output (that is, as though 

holding output constant). This effect includes both changes in employment due to 

incorporation of abatement technologies and overall changes in the labor intensity of 

manufacturing. We estimate the substitution effect by multiplying the ratio of workers to 

each $1 million of expenditures in the auto sector by the cost estimates for complying 

with the rule. This approach estimates the effects of increased expenditures while 

holding constant the labor intensity of manufacturing; it does not take into account 
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changes in labor intensity due to changes in the nature of production. This latter effect 

could either increase or decrease the employment impacts estimated here.596

Some of the costs of this rule will be spent directly in the auto manufacturing 

sector, but it is also likely that some of the costs will be spent in the auto parts 

manufacturing sector. We separately present the ratios for both the auto manufacturing 

sector and the auto parts manufacturing sector.

There are several public sources for estimates of employment per $1 million 

expenditures. As discussed in the RIA, EPA examines several sources for these 

estimates: the U.S. Bureau of Labor Statistics (BLS)’s Employment Requirements 

Matrix (ERM),597 the Census Bureau’s Annual Survey of Manufactures598 (ASM), and its 

Economic Census. The use of these ratios has both advantages and limitations. It is 

often possible to estimate these ratios for quite specific sectors of the economy: for 

instance, it is possible to estimate the average number of workers in the light-duty vehicle 

manufacturing sector per $1 million spent in the sector, rather than use the ratio from 

another, more aggregated sector, such as motor vehicle manufacturing. As a result, it is 

not necessary to extrapolate employment ratios from possibly unrelated sectors. On the 

other hand, these estimates are averages for the sectors, covering all the activities in those 

sectors; they may not be representative of the labor required when expenditures are 

required on specific activities, or when manufacturing processes change sufficiently that 

labor intensity changes. For instance, the ratio for the motor vehicle manufacturing 

sector represents the ratio for all vehicle manufacturing, not just for emissions reductions 

associated with compliance activities. In addition, these estimates do not include changes 

in sectors that supply these sectors, such as steel or electronics producers. They thus may

best be viewed as the effects on employment in the specific sectors due to the changes in 

expenditures in those sectors, rather than as an assessment of all employment changes 

due to these changes in expenditures.

The values used here are adjusted to remove the employment effects of imports 

through use of a ratio of domestic production to domestic sales of 0.667.599 As discussed 

in the RIA, trends in the BLS ERM are used to estimate productivity improvements over 

time that are used to adjust these ratios over time.

 

596 As noted above, Morgenstern et al. (2002) separate the effect of holding output constant into two 

effects: the cost effect, which holds labor intensity constant, and the factor shift effect, which estimates 

those changes in labor intensity.

597 Bureau of Labor Statistics. Employment Requirements Matrix. 

http://www.bls.gov/emp/ep_data_emp_requirements.htm (Docket EPA-HQ-OAR-2011-0135).

598 U.S. Census Bureau. Annual Survey of Manufactures. 

http://www.census.gov/manufacturing/asm/index.html (Docket EPA-HQ-OAR-2011-0135).

599 To estimate the proportion of domestic production affected by the change in sales, we use data from 

Ward’s Automotive Group for total car and truck production in the U.S. compared to total car and truck 

sales in the U.S. For the period 2001-2010, the proportion is 66.7 percent (Docket EPA-HQ-OAR-2011-

0135-0333).
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Table X-1 provides estimates of the substitution effect of this rule on 

employment. Chapter 2.1 of the RIA discusses the vehicle cost estimates developed for 

this rule, discussed in Section VII.A, presented in the second column. The maximum 

value for employment impacts per $1 million (2011$) (before adjustments for changes in 

productivity, after accounting for the share of domestic production) is 1.771 if all the 

additional costs are in the parts sector; the minimum value is 0.389, if all the additional 

costs are in the light-duty vehicle manufacturing sector. Increased costs of vehicles and 

parts will, by itself, and holding labor intensity constant, be expected to increase 

employment between 2017 and 2025 by some hundreds of jobs each year.

While we estimate employment impacts, measured in job-years, beginning with 

program implementation, some of these employment gains may occur earlier as auto 

manufacturers and parts suppliers hire staff in anticipation of compliance with the 

standard. A job-year is a way to calculate the amount of work needed to complete a 

specific task. For example, a job-year is one year of work for one person.

Table X-1 Employment Effects due to Increased Costs of Vehicles and Parts, in jobyears

Year Costs 

(Millions of 

2010$)

Maximum Employment 

Effect (if all expenditures 

are in the Parts Sector)

Minimum Employment Effect 

(if all expenditures are in the 

Light Duty Vehicle Mfg 

Sector)

2016 $ 21 0 0 

2017 $ 297 400 100 

2018 $ 615 800 200 

2019 $ 653 800 200 

2020 $ 697 800 200 

2021 $ 725 800 200 

2022 $ 758 800 200

2023 $ 751 800 200 

2024 $ 761 800 200 

2025 $ 773 700 200 

c. Summary of Employment Effects in the Auto Sector

The overall effect of the standards on auto sector employment depends on the 

relative magnitude of the output effect and the substitution effect. Because we do not 

have quantitative estimates of the output effect, and only a partial estimate of the 

substitution effect, we cannot reach a quantitative estimate of the overall employment 

effects of the standards on auto sector employment or even whether the total effect will 

be positive or negative. However, given that the expected increase in production costs to 

the auto manufacturers is relatively small, we expect that the magnitudes of all these 

effects will be small as well. 
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Additionally, the standards are not expected to provide incentives for 

manufacturers to shift employment between domestic and foreign production. This is 

because the increased standards of the rule will apply to vehicles sold in the U.S. 

regardless of where they are produced. If foreign manufacturers already have increased 

expertise in satisfying the requirements of the rule, there may be some initial incentive 

for foreign production, but the opportunity for domestic manufacturers to sell in other 

markets might increase. To the extent that the requirements of this rule might lead to 

installation and use of technologies that other countries may seek now or in the future, 

developing this capacity for domestic production now may provide some additional 

ability to serve those markets. This potential benefit for domestic production will not 

apply if other countries are not likely to have similar standards.

2. Refinery Employment Impacts

The Berman and Bui (2001) framework of output and substitution effects can also 

be applied to the impact of the rule on employment in the refinery sector. Here we use a 

fully qualitative approach. A qualitative discussion allows for a wider incorporation of 

additional considerations, such as timing of impacts and the effects of the rule on imports 

and exports. Because the discussion is qualitative, we do not sum the net effects on 

employment. 

The output effect on refining sector employment is expected to be negative. The 

discussion in Section X.C above suggested that the standards will cause a small decrease 

in the quantity of gasoline demanded due to higher production costs being passed through 

to consumers. This slightly reduced level of sales will likely have a negative impact on 

employment in the refining sector. While we do not quantify the level of job losses that 

could be expected here, recall that the quantity of gasoline sold as a result of these 

standards is expected to decrease by only a very small amount over any time horizon. 

The substitution effect of the standards on employment in the refining sector can 

be either positive or negative in the Berman and Bui framework; here, we expect a small, 

possibly positive impact. In order to satisfy the requirements of the rule, firms in the 

refining industry are expected to perform additional work that will require hiring more 

employees, especially perhaps in the short run. Section V.L.2.e discusses the expected 

employment needed to reduce the sulfur content of fuels; as noted there, to meet the Tier 

3 sulfur standards, refiners are expected to invest $2 billion between 2012 and 2019 and 

utilize approximately 250 front-end design and engineering jobs and 1,500 construction 

jobs. As the petroleum sector employed approximately 71,000 workers in 2011, this 

temporary increase in employment will be small when compared to 2011 levels.

Chevron Products Company states that we have not considered global competitive 

forces in our assessment. As we discussed in the NPRM, this rule is not expected to 

provide incentives to shift employment between domestic and foreign production. First, 

the standards will apply to gasoline sold in the U.S. regardless of where it has been 

produced. U.S. gasoline demand is projected to continue to decline for the foreseeable 
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future in response to higher gasoline prices, more stringent vehicle and engine 

greenhouse gas and fuel economy standards as well as increased use of renewable fuels. 

As a result, this analysis of incentives to shift employment between domestic and foreign 

production focuses on investments for existing capacity instead of expanding capacity.

600

 

In this case, what is relevant is whether the necessary modifications to comply with Tier 

3 will be significantly cheaper overseas than in the U.S. 

The main impacts on capital and operating costs to comply with Tier 3 associated 

with adding hydrotreating capacity are likely to be similar overseas as in the U.S. This is 

particularly true when analyzing likely sources of U.S. imports. The majority of gasoline 

imported to the U.S. today comes into the East Coast and is sourced out of either Europe 

or refineries in Canada or the Caribbean that exist almost solely to supply the U.S. 

market. These Canadian and Caribbean refineries, by virtue of their focus on the U.S. 

market, are very similar to U.S. based refineries and would be expected to have to incur 

similar capital and operating costs as their U.S. based competitors meeting the 10 ppm 

standard. Furthermore, the European refineries are already producing gasoline to a 10 

ppm sulfur cap for Europe. To the extent they have refinery streams that are more 

difficult to hydrotreat, the U.S. market currently serves as an outlet for their higher sulfur 

gasoline streams. As a result, they may incur capital and operating costs on a per gallon 

basis at least as high as for their U.S. based competitors for these remaining higher sulfur 

gasoline streams. Alternatively, they may instead choose to find markets outside the 

U.S., opening the way for increased U.S. based refinery demand. 

Finally, despite refining industry projections that previously imposed diesel rules 

would lead to greater U.S. reliance on imports through major negative impacts on 

domestic refining, the reverse has actually occurred. Over the last 8 years, imports of 

gasoline and diesel fuel have continued to be the marginal supply, and have even dropped 

precipitously so that the U.S. is now a net exporter of diesel fuel and is importing half the 

gasoline that it did at its peak in 2006. With the projected decline in future gasoline 

demand in the U.S. as vehicle fuel efficiency improves, gasoline imports are expected to 

continue to decline.

Thus it is expected that for the refining sector, the output effect will lower 

employment, and the substitution effect will raise employment. As a whole then, it is not 

evident whether the standards will increase or decrease employment in the refining 

sector. However, given the small anticipated reduction in quantity sold, it appears that 

the standards will not have major employment consequences for this sector. 

The petroleum refining industry is one of the manufacturing industries studied by

Berman and Bui (2001) when they looked at the effect of environmental expenditures on 

employment. They found that “Employment effects are very small, generally positive, 

 

600 While refinery capacity has been increasing around the world in recent years, it has been designed 

primarily to supply foreign markets other than the U.S. (e.g., increasing demand in China and India).
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but not statistically different from zero.” (p. 281) [Berman and Bui, Table 3]. Berman and 

Bui also state that the estimates rule out large negative effects (p. 282). Because most of

the abatement cost of the regulations they analyze is incurred by refineries, in their 

sample, they report separate employment effects for refineries and non-refineries “which 

are also all small.” (p. 282). Berman and Bui suggest some explanations for the zero or 

small estimates, particularly for oil refineries: they are capital-intensive industries with 

relatively little employment when compared to other manufacturing; they face relatively 

inelastic demand because they sell output in local markets and/or because there are no 

unregulated refineries to compete with; and, finally, regulations may have been 

associated with productivity gains in petroleum refineries. We note that the regulations 

that these estimates are derived from are not directly comparable to the current rule; they

are based on the costs of reductions in refinery air pollution emissions instead of 

changing fuel properties, and therefore may not be applicable for these standards. The 

American Petroleum Institute requested that we delete reference to use of analysis by

Morgenstern et al. (2002) because it is based on temporary construction jobs and a single 

study. We had presented that figure not as a conclusive estimate, but rather as one 

estimate that we too consider of unclear applicability to the standards; we have 

substituted Berman and Bui’s results. Several commenters cite a study by Navigant 

Economics that estimates 24,500 installation jobs during the first three years of the 

program, and 5,300 permanent jobs, associated with the refinery standards. These 

estimates include employment not just in the refinery sector, but also multiplier effects 

(discussed above) for suppliers, which EPA does not estimate. As noted above, EPA 

estimates approximately 250 front-end design and engineering jobs and 1,500 

construction jobs. 

Section 5.3 of the RIA contains some historical discussion regarding the impact 

on refineries and refining capacity of earlier rules which resulted in higher costs for 

refiners. Over the period 2003-2011, when a number of rules were being implemented, 

EIA data show a net of two refinery closures on its website. Meanwhile, over this same 

period the average size of U.S. refineries increased from 113,000 barrels per day to 

123,000 barrels per day, and total U.S. refining capacity increased by six percent. Thus, 

historically during a time when rules with much larger expected impacts were being 

implemented (the 2003 ultra-low sulfur nonroad diesel proposal alone was expected to 

have a cost impact on refineries more than five times greater than the current rule), U.S. 

refining capacity increased even as the number of U.S. refineries slightly fell. While 

closing refineries has a negative effect on industry employment, it is likely that the 

increased refining capacity at many of the remaining plants had a positive effect on 

industry employment.

The standards are also likely to have a positive impact on employment among 

producers of equipment that refiners will use to comply with the standards. Section 

V.A.2.c notes that some refiners are expected to need to revamp their current treatment 

units, and others will need to add additional treatment units. Producers of this equipment 

will be expected to hire additional labor to meet this increased demand. We also note 

that the employment effects may be different in the immediate implementation phase than 
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in the ongoing compliance phase. It is expected that the employment increases through 

the substitution effect from revamping old equipment and installing additional equipment 

should occur in the near term, when current unemployment levels are high, and the 

opportunity cost of workers is relatively low. Meanwhile, the employment decreases in 

the refining sector from the output effect will not start until 2017, when compliance will 

be required, and when unemployment is expected to be reduced; in a time of full 

employment, any changes in employment levels in the regulated sector are mostly

expected to be offset by changes in employment in other sectors. 

XI. Public Participation

Many interested parties participated in the rulemaking process that culminates 

with this final rule. This process provided opportunity for submitting written public 

comments following the proposal that we published on May 21, 2013 (78 FR 29816), and 

we considered these comments in developing the final rule. In addition, we held public 

hearings on the proposed rulemaking on April 24 and 29, 2013, and we have considered 

comments presented at the hearing.

Throughout the rulemaking process, EPA met with stakeholders including 

representatives from various industries (vehicle manufacturers, fuel refiners, fuel 

distributors, suppliers, engine manufacturers, etc.), states, non-governmental 

organizations, and others.

We have prepared a detailed Summary and Analysis of Comments document, 

which describes the comments we received on the proposal and our responses. The 

Summary and Analysis of Comments is available in the docket for this rule at the Internet 

address listed under ADDRESSES, as well as on the Office of Transportation and Air 

Quality Web site (http://www.epa.gov/tier3.htm). In addition, comments and responses 

for key issues are included throughout this preamble.

XII. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and Executive Order 

13563: Improving Regulation and Regulatory Review

Under section 3(f)(1) of Executive Order 12866 (58 FR 51735, October 4, 1993), 

this action is an “economically significant regulatory action” because it is likely to have 

an annual effect on the economy of $100 million or more. Accordingly, EPA submitted 

this action to the Office of Management and Budget (OMB) for review under Executive 

Orders 12866 and 13563 (76 FR 3821, January 21, 2011) and any changes made in 

response to OMB recommendations have been documented in the docket for this action.

In addition, EPA prepared an analysis of the potential costs and benefits 

associated with this action. This analysis is contained in Sections VII and VIII of this 
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preamble and in Chapter 8 of the RIA. A copy of the analysis is available in the docket 

for this action.

B. Paperwork Reduction Act

This action is continuing existing information collection from the Tier 2 program, 

with additional changes as noted below. The Office of Management and Budget (OMB) 

has previously approved the information collection requirements contained in the existing 

the existing Tier 2 gasoline rule (65 FR 6698, February 10, 2000), under the provisions of 

the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. The ICRs were assigned OMB 

Control Numbers 2060-0437 (fuels), 2060-0104 (light-duty vehicles), 2060-0287 (heavyduty vehicles), and 2060-0086 (in-use verification program). The ICRs are being revised 

to reflect the changes being finalized today. The additional information collection

requirements in this rule will be submitted for approval to OMB under the Paperwork 

Reduction Act. The information collection requirements are not enforceable until OMB 

approves them.

This rule contains reporting and recordkeeping requirements to implement EPA’s 

motor vehicle certification program and the manufacturers’ in-use verification program 

(IUVP). Existing regulations require manufacturers to submit emissions information to 

EPA in conjunction with these two programs. Manufacturers must submit an application 

for emission certification prior to production. The application describes the major 

aspects of the product line, technical details of the emission control systems, and the 

results of tests to indicate compliance with the emissions limitations. The application and 

supporting test results are reviewed and, if appropriate, a certificate of conformity is 

issued. Subsequently, low- and high-mileage vehicles in use are tested for emissions by

manufacturers and the results of those tests reported to EPA. EPA estimates the total 

number of respondents to be 55, the total burden hours to be 73,567, and the total cost to 

respondents to be $7,690,934.

As a result of the change in certification test fuel from 9 RVP E0 to 9 RVP E10, 

EPA must assess the need to make test procedure adjustments related to fuel economy 

testing such that the change in test fuel quality does not impact the stringency of the 

CAFE standards. EPA recognized that this action was needed in the proposed rule, but 

deferred proposing a specific adjustment or set of adjustments because the data needed to 

determine the value(s) for the adjustments was not available. Historically, manufacturers 

have used criteria pollutant emission information from the exhaust emission testing for 

certification as part of the data needed to determine fuel economy values. The final rule 

sets a process in motion for EPA to gather the information need to develop any test 

procedure adjustments. While the basic data will likely be available in late 2015 or early 

2016, any rule to enact potential test procedure adjustments will take additional time. 

During this interim period, any LEV III or early Tier 3 vehicles using E10 test fuel for 

exhaust emission certifications will have to be tested for fuel economy values on E0. 

EPA has studied the expected phase-in rates for these vehicles in LEV III and estimates 

that for the 2015-2017 model years there will an average about 35 additional tests per 
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year for the industry with an hour burden of about 30 hours per test. Thus, over this 

three-year period, the added hour burden is 1050 hours and the sum of the cost of testing 

and the hour burden is $402,150.

This rule also contains reporting, recordkeeping, and Product Transfer Document 

(PTD) requirements for refiners and importers of motor vehicle gasoline. This rule 

contains registration, reporting, recordkeeping, and PTD requirements for producers and 

importers of denatured fuel ethanol (DFE) and other oxygenates. This rule also contains 

registration, recordkeeping, and PTD requirements for producers of certified ethanol 

denaturants. This rule also contains recordkeeping and PTD requirements for producers 

of gasoline additives. The reporting, recordkeeping, and PTD requirements for refiners 

and importers of motor vehicle gasoline are the same requirements that exist under the 

Tier 2 sulfur program.601 The registration and reporting requirements for DFE producers 

and importers are new as are the registration requirements for producers and importers of 

certified ethanol denaturants. The recordkeeping and PTD requirements for gasoline 

additive producers, DFE manufacturers, ethanol denaturant manufacturers, and 

downstream parties under the Tier 3 program are new but should be minimal since we 

expect that they are already followed as part of normal business practices. EPA estimates 

the total number of respondents to be 2,675, the total burden hours to be 84,000 and the 

total cost to respondents to be $6,300,000.

Finally, this rule also contains provisions for qualifications of laboratories on test 

methods. We have adopted recordkeeping and reporting requirements that would apply

to fuel testing laboratories. The collected data will permit EPA to: (1) Qualify

laboratories to use test methods based upon accuracy and precision criteria supported by

industry; and (2) Ensure that various fuels meet the standards required under the 

regulations at 40 CFR part 80 and that the associated benefits to human health and the 

environment are realized. We estimate that 750 laboratories may be subject to the 

information collection. This estimate is based upon our experience with qualification of 

laboratories under the existing diesel sulfur program. We estimate an annual reporting 

burden of 95 hours per respondent and an annual recordkeeping burden of 104 hours, 

yielding a total of 199 hours. For those laboratories that elect to be reference 

installations, the annual reporting burden would be 95 hours and the annual 

recordkeeping burden would be 128 hours. Burden is defined at 5 CFR 1320.3(b).

The ICR supporting statements can be found in Docket ID number EPA–HQ–

OAR–2011–0135.

An agency may not conduct or sponsor, and a person is not required to respond to 

a collection of information unless it displays a currently valid OMB control number. The 

OMB control numbers for EPA’s regulations in 40 CFR are listed in 40 CFR part 9. 

 

601 65 FR 6698, February 10, 2000; OMB Control Number: 2060-0437; EPA ICR 1907.05
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When the ICRs are approved by OMB, the Agency will publish a technical amendment to 

40 CFR part 9 in the Federal Register to display the OMB control numbers for the 

approved information collection requirements contained in this final rule.

We did not receive any specific comments on the ICR; comments received 

regarding compliance-related provisions are discussed above in Sections IV and V. 

C. Regulatory Flexibility Act

1. Overview

The Regulatory Flexibility Act (RFA) generally requires an agency to prepare a 

regulatory flexibility analysis of any rule subject to notice and comment rulemaking 

requirements under the Administrative Procedure Act or any other statute unless the 

agency certifies that the rule will not have a significant economic impact on a substantial 

number of small entities. Small entities include small businesses, small organizations, 

and small governmental jurisdictions.

For purposes of assessing the impacts of today’s rule on small entities, small 

entity is defined as: (1) a small business as defined by the Small Business 

Administration’s (SBA) regulations at 13 CFR 121.201 (see table below); (2) a small 

governmental jurisdiction that is a government of a city, county, town, school district or 

special district with a population of less than 50,000; and (3) a small organization that is 

any not-for-profit enterprise which is independently owned and operated and is not 

dominant in its field.

The following table provides an overview of the primary SBA small business 

categories potentially affected by this regulation:

Industry NAICSa 

Code (2007)

Defined as small entity by SBA 

if less than or equal to:

Gasoline fuel refiners and 

importers

324110 1,500 employees

Ethanol producers 325193 1,000 employees

Gasoline additive manufacturers 325199, 

325998, 

424690

1,000 employees

500 employees

100 employees

Transmix processors Varied 1,500 employees

Petroleum bulk stations and 

terminals

424710 100 employees

Other warehousing and storagebulk petroleum storage493190 $25.5 million (annual receipts)

Light-duty vehicle and light-duty 

truck manufacturers

336111,

336112

1,000 employees
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Independent commercial 

importers

811111, 

811112, 

811198

$7 million (annual receipts)

Alternative fuel converters 335312,

336312,

336322,

336399,

811198

1,000 employees

750 employees

”

”

$7 million (annual receipts)

On-highway heavy-duty engine 

& vehicle (>8,500 lbs GVWR) 

manufacturers

333618,

336120,

336211,

336312

1,000 employees

”

”

750 employees

Note:

a North American Industrial Classification System

2. Background

EPA’s Tier 2 Vehicle and Gasoline Sulfur Program, which was finalized in 

February 2000, took a systems-based approach to motor vehicle pollution by setting 

standards for both passenger vehicles and their fuel (gasoline). The program set stricter 

tailpipe and evaporative emissions standards for criteria pollutants from vehicles 

beginning with model year (MY) 2004 and phasing in through 2009. The program also 

lowered the sulfur content of gasoline, to a 30 ppm refinery average, 80 ppm per-gallon 

cap, and 95 ppm downstream cap; beginning in 2004 and phasing in through 2008. The 

potential to extend the phase-in for small refiners and approved Gasoline Phase-In Area 

(GPA) refiners through the end of 2010 was provided in the Highway Diesel Rule602 in 

exchange for early compliance with the diesel program. Similar to the Tier 2 rule, the 

Tier 3 program is a comprehensive, systems-based approach to address the impact of 

light-duty vehicles and certain heavy-duty vehicles on air quality and health.

Pursuant to section 603 of the RFA, EPA prepared an initial regulatory flexibility

analysis (IRFA) for the proposed rule and convened a Small Business Advocacy Review 

Panel to obtain advice and recommendations of representatives of the regulated small 

entities (see 78 FR 29816, May 21, 2013). A detailed discussion of the Panel’s advice 

and recommendations is found in the Panel Report, located in the rulemaking docket 

(document number: EPA-HQ-OAR-2011-0135-0423). A summary of the Panel’s 

recommendations is presented at 78 FR 29994 (May 21, 2013).

As required by section 604 of the RFA, we also prepared a final regulatory 

flexibility analysis (FRFA) for today’s final rule. The FRFA addresses the issues raised 

by public comments on the IRFA, which was part of the proposal of this rule. The FRFA 

 

602 66 FR 5136 (January 18, 2001).
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is available for review in the docket (see Chapter 10 of the RIA) and is summarized 

below.

3. Reason for Today’s Rule

This rule establishes more stringent vehicle emissions standards and reduces the 

sulfur content of gasoline beginning in 2017, as part of a systems approach in addressing 

the impacts of motor vehicles and fuels on air quality and public health. The gasoline 

sulfur standards will make emission control systems more effective and enable more 

stringent vehicle emissions standards, and the vehicle standards will reduce vehicle 

tailpipe and evaporative emissions. This will result in significant reductions in pollutants 

such as ozone, particulate matter, and air toxics. For a more detailed discussion of the 

reasoning for today’s rule, please see Sections II and III of this preamble. The vehicle 

and fuel programs are further discussed in Sections IV and V, respectively.

4. Legal Basis for Agency Action

The Clean Air Act (CAA) authorizes EPA to establish emissions standards for 

motor vehicles to address air pollution that may reasonably be anticipated to endanger 

public health or welfare. EPA also has authority to establish fuel controls to address such 

air pollution. The authority for the vehicle emission standards comes from CAA section 

202(a), Section 202(k) provides EPA with authority to issue and revise regulations 

applicable to evaporative emissions of hydrocarbons from gasoline-fueled motor 

vehicles, and section 206(d) authorizes EPA to establish methods and procedures for 

testing whether a motor vehicle or motor vehicle engine conforms with section 202 

requirements. The authority for the fuel standards comes from section 211(c).

For more detailed information on our legal authority for today’s proposal, please 

see Sections II.A and V.M of this preamble.

5. Summary of Potentially Affected Small Entities

The table above lists industries/sectors potentially affected by the Tier 3 rule. For 

businesses potentially impacted by the Tier 3 vehicle standards, this includes vehicle 

manufacturers, alternative fuel converters, and independent commercial importers. For 

businesses potentially impacted by the Tier 3 gasoline sulfur standards, this includes 

gasoline refiners and importers, distributors, fuel additive manufacturers, transmix 

processors, and ethanol producers.

EPA used a variety of sources to identify which entities are appropriately 

considered “small.” EPA used the criteria for small entities developed by the Small 

Business Administration under the North American Industry Classification System 

(NAICS) as a guide. Information about these entities comes from sources including the 

Energy Information Administration (EIA) within the U.S. Department of Energy, oil 

industry literature, EPA’s certification data, and previous rulemakings that have affected 

these industries. EPA then found employment information for these companies using the 
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business information database Hoover’s Online (a subsidiary of Dun and Bradstreet). 

These entities fall under the categories listed in the table.

6. Reporting, Recordkeeping, and Compliance

For any emission control program, EPA must have assurances that the regulated 

products will meet the standards. The program that EPA is finalizing for manufacturers 

subject to this rule will include testing, reporting, and recordkeeping requirements for 

manufacturers of vehicles covered by the Tier 3 regulations. Testing requirements for 

these manufacturers will include certification emission (including deterioration factor) 

testing, in-use testing, and production line testing. Reporting requirements will include 

emission test data and technical data on the vehicles. Manufacturers must keep records 

of this information.

Similarly for any fuel control program, EPA must have the assurance that fuel 

produced, distributed, sold and used meets the applicable standard. The recordkeeping, 

reporting, and compliance provisions of this rule are consistent with those in place today

for other fuel programs. Further, we will use existing registration and reporting systems 

that parties in the fuel production and distribution industry are already familiar with.

7. Related Federal Rules

The primary federal rules that are related to this final rule are: the Tier 2 

Vehicle/Gasoline Sulfur rulemaking (65 FR 6698, February 10, 2000), the 2017 Lightduty Greenhouse Gas (LD GHG) rule (77 FR 62623), and the Greenhouse Gas Emissions 

Standards and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and 

Vehicles (HD GHG) rule (76 FR 57106). 

The LD GHG and HD GHG rules are coordinated efforts by EPA and the 

National Highway Traffic Safety Administration (NHTSA) taking steps to reduce GHG 

emissions and improve fuel efficiency from on-road vehicles and engines.

8. Steps Taken to Minimize the Economic Impact on Small Entities

a. Significant Panel Findings

The Small Business Advocacy Review Panel (SBAR Panel, or the Panel) 

considered regulatory options and flexibilities to help mitigate potential adverse effects 

on small businesses as a result of this rule. During the SBREFA Panel process, the Panel 

sought out and received comments on the regulatory options and flexibilities that were 

presented to SERs and Panel members. As described below, much of the Panel’s 

recommendations were proposed, and many of those flexibilities are being finalized 

today. (The recommendations of the Panel are also located in Section 9 of the SBREFA 

Final Panel Report, which is available in the public docket.)
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In today’s action we are also finalizing some additional flexibilities that were not 

discussed during the Panel process.

b. Outreach with Small Entities and the Panel Process

As required by section 609(b) of the RFA, as amended by SBREFA, we 

conducted outreach to small entities and convened an SBAR Panel on August 4, 2011 to 

obtain advice and recommendations of representatives of the small entities that would be 

subject to the Tier 3 requirements.

As part of the SBAR Panel process, we conducted outreach with representatives 

of small businesses that would be affected by the rule. We met with these SERs to 

discuss the potential rulemaking approaches and flexibility options to decrease the impact 

of the rulemaking on their industries. The SERs provided written comments to the Panel, 

specifically on regulatory alternatives that could help to minimize the rule’s impact on 

small businesses.

The Panel’s findings and discussions were based on the information that was 

available during the term of the Panel and issues that were raised by the SERs during the 

outreach meetings and in their comments. It was agreed that EPA should consider the 

issues raised by the SERs and discussions had by the Panel itself, and that EPA should 

consider comments on flexibility alternatives that would help to mitigate negative 

impacts on small businesses to the extent legally allowable by the Clean Air Act. 

Alternatives discussed throughout the Panel process included those offered in previous or 

current EPA rulemakings, as well as alternatives suggested by SERs and Panel members. 

A full discussion of the regulatory alternatives and hardship provisions discussed and 

recommended by the Panel can be found in the SBREFA Final Panel Report, located in 

the rulemaking docket. A summary of the Panel’s recommendations, what the Agency

proposed, and what is being finalized today is discussed below. (A more detailed 

discussion of the final provisions for small entities can be found in Sections IV.G and 

V.E.)

It should be noted that during the Panel process, two additional issues were

discussed with SERs. EPA was considering extending the new certification fuel 

specifications to all regulatory categories of engines, vehicles, equipment, and fuel 

system components that use gasoline. This would have included a wide range of 

additional applications, including small nonroad engines used in lawn and garden 

applications, recreational vehicles such as ATVs and snowmobiles, recreational marine 

applications, on-highway motorcycles, and heavy-duty gasoline engines. In addition, 

EPA considered new volatility (Reid Vapor Pressure, or RVP) standards for in-use 

gasoline. Neither of these issues was proposed, thus the discussion of Panel 

recommendations below does not address these issues, however they are addressed in the 

Final Panel Report.
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c. Panel Recommendations, Proposed Provisions, and Provisions Being Finalized 

Today

i. Tier 3 Fuels

(1) Lead Time—Sulfur

The Panel recommended that EPA allow small refiners to postpone their 

compliance with the Tier 3 program for up to three years. EPA proposed, and is 

finalizing, this provision. Approved small refiners will have from January 1, 2017 

through December 31, 2019 to continue production of gasoline with an average sulfur 

level of 30 ppm (per the Tier 2 gasoline sulfur program). Compliance with the 10 ppm 

annual average sulfur standard will begin on January 1, 2020. As discussed further in 

Section V.D.6, small refiners may continue to generate sulfur credits relative to the 30 

ppm sulfur standard through December 31, 2019. Comments received on the small 

refiner provisions were generally supportive of the proposed three-year delay. However, 

commenters did not agree with EPA’s proposal that small refiners could only generate 

early credits relative to the 10 ppm sulfur standard beginning January 1, 2017, and 

requested an early credit generation period for small refiners relative to the 30 ppm sulfur 

standard.

As small refiners will still be subject to the 30 ppm sulfur standard when the Tier 

3 program begins on January 1, 2017, we are finalizing that small refiners may continue 

to generate credits relative to 30 ppm through December 31, 2019. Additionally, from 

January 1, 2017 through December 1, 2019, small refiners may split their credit 

generation between both the 10 ppm and 30 ppm standards (without double-counting). 

For example, during this time period, a small refiner with an average gasoline sulfur level 

of 8 ppm could generate 20 ppm-volume credits (30-10 ppm, relative to the 30 ppm Tier 

2 sulfur standard) plus 2 ppm-volume credits (10-8 ppm, relative to the 10 ppm Tier 3 

sulfur standard).

(2) Provisions for Additive Manufacturers

During the SBREFA Panel process, different requirements than those proposed 

(and being finalized today) were discussed for additive manufacturers. Thus, the 

provisions recommended by the Panel were not applicable to the provisions proposed and 

now finalized for these parties. More information on the Panel’s recommendations for 

gasoline additive manufacturers can be found in the Final Panel Report, located in the 

rulemaking docket.

We proposed that parties introducing additives to gasoline greater than 1.0 

volume percent would be required to satisfy all of the obligations of a fuel manufacturer, 

including demonstration that the finished blend meets the applicable sulfur specification. 

We also proposed a maximum sulfur contribution of 3 ppm from the use of a gasoline 

additive added downstream of the refinery at less than 1.0 volume percent (when added at 

the maximum recommended treatment rate). Lastly, we proposed that additive 
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manufacturers would need to maintain records of their additive production quality control 

activities for five years.

As discussed further in Section V.C., we are finalizing the requirement that 

manufacturers of gasoline additives used downstream of the refinery at less than 1.0 

volume percent must limit the sulfur contribution to the finished gasoline from the use of 

the additive to less than 3 ppm when the additive is used at the maximum recommended 

treatment rate. For each batch of additive produced, the manufacturer must retain sulfur 

test records for five years, and must make these records available to EPA upon request. 

Parties that introduce additives to gasoline at over 1.0 volume percent will be required to 

satisfy all of the obligations of a fuel manufacturer, including demonstration that the 

finished blend meets the applicable sulfur specification.

(3) Refinery Gate and Downstream Caps

The Panel recommended that EPA assess and request comment on retaining the 

current Tier 2 refinery gate and downstream caps of 80 and 95 ppm, respectively, to help 

provide maximum flexibility and avoid system upsets for the entire refining and 

distribution system. The Panel also recommended that EPA request comment on 

additional refinery gate and downstream caps above 20/25 ppm but below 80/95 ppm. 

The Panel expressed concern with a refinery gate cap as low as 20 ppm, because such a 

standard could cause operational problems for small refiners during a refinery turnaround 

or an upset—a cap of this level could result in a refiner not being able to produce 

gasoline. The Panel likewise expressed concerns that a downstream cap of 25 ppm could 

cause problems for small downstream entities, such as transmix processors, because they

may not be able to reprocess finished gasoline down to this level.

In the proposal, EPA co-proposed caps of 80/95 ppm and 50/65 ppm and took 

comment on caps at 20/25 ppm. However, as discussed above in Section V.C, we are 

finalizing retaining the Tier 2 80 and 95 ppm caps. Since we are retaining the same caps 

from the Tier 2 program that entities in the fuel industry are currently complying with, we 

do not believe that additional flexibilities with respect to the refinery gate and 

downstream sulfur caps are needed.

(4) Hardship Provisions

The Panel recommended that EPA propose hardship provisions for all gasoline 

refiners and importers, similar to those in prior EPA fuels programs: (a) the extreme 

unforeseen circumstances hardship provision, and (b) the extreme hardship provision. 

The Panel also recommended that if EPA were to propose lower refinery gate and 

downstream caps, EPA should also consider hardship relief in the form of long-term 

relief on the sulfur cap if the circumstances both warrant it and can be structured in a way

to allow for it. EPA proposed, and is finalizing, both the extreme unforeseen 

circumstances and extreme hardship provisions for all gasoline refiners and importers. 

As described in Section V.E.2, hardship relief will be granted on a case-by-case basis 
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following a showing that compliance (especially through the use of credits) is not 

feasible. If a hardship waiver is granted, EPA will determine appropriate hardship relief 

based on the refiner’s hardship application and an assessment of the credit market at that 

time.

ii. Tier 3 Vehicles

As discussed in Section 5 of the Panel Report, in addition to vehicle 

manufacturers, two categories that include small businesses are covered by the new 

vehicle standards: independent commercial importers (ICIs), and alternative fuel vehicle 

converters. As discussed below, EPA’s expectation at the time of the Panel process was 

to propose a set of flexibilities that would be available to all small entities in these three 

business categories as well as to small volume manufacturers (SVMs) that sell less than 

5,000 vehicles per year. The Panel identified a number of entities covered by the vehicle 

standards that qualify as small businesses under the SBA definition. Six of these 

companies participated as SERs.

The Panel and SERs discussed several regulatory flexibility alternatives for small 

businesses that certify vehicles subject to the proposed Tier 3 emission standards. As 

described in Appendix A of the Panel Report, EPA sought comment from the SERs on 

allowing small entities to skip the Tier 3 phase-in and instead implement Tier 3 

requirements for all of their vehicles following the phase-in period. In addition, EPA 

sought comment on the following flexibilities: (1) a hardship relief provision that would 

allow these businesses to apply for additional time to meet the requirements, (2) use of 

assigned deterioration factors for certification purposes, and (3) reduction in the number 

of tests required in the manufacturer in-use verification testing program. SERs were 

generally supportive of these flexibility provisions. However, one SER requested that 

EPA consider providing relaxed standards for exhaust emissions in addition to the delay, 

and another SER requested that we consider eliminating some of the evaporative 

emissions testing requirements. 

The recommendations made by the Panel on these approaches are discussed in 

detail in Section XII.C of the NPRM. We consequently proposed small business and 

small volume manufacturer provisions based on these recommendations, as summarized 

in Section IV.G above. These proposed provisions consisted of additional lead time, 

reduced testing requirements, and opportunities for hardship relief, that would help small 

entities to leverage technological developments by others and to spread the availability of 

needed engineering, supplier, and capital resources. Based on the comments we 

subsequently received during the public comment period, we have improved on the 

proposed provisions and are finalizing Tier 3 vehicle provisions for small businesses and 

SVMs as described in detail in Section IV.G above, consisting of:

 An alternative NMOG+NOx light-duty fleet average standard phase-in schedule for 

small businesses and SVMs: 125 mg/mi for MYs 2017-2021, 51 mg/mi for MYs 

2022-2027, and 30 mg/mi thereafter;
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 An optional delay of Tier 3 requirements until MY 2022 for small businesses and 

SVMs;

 EPA-assigned deterioration factors for small businesses and SVMs (as well as for 

small volume test groups);

 Reduced in-use testing requirements for SVMs with annual sales under 15,000, 

including no required testing for those with annual sales under 5,000;

 A PM testing waiver for small businesses and SVMs;

 An allowance for small alternative fuel vehicle converters to meet existing OBD 

requirements (40 CFR 86.1806-05) instead of new Tier 3 requirements;

 A provision for small businesses and SVMs in hardship situations to apply for 

additional time to meet the Tier 3 standards;

 An extension of eligibility for the Tier 3 SVM provisions to small manufacturers that 

are owned by large manufacturers but are able to demonstrate that they are 

operationally independent. 

As required by section 212 of SBREFA, EPA also is preparing a Small Entity

Compliance Guide to help small entities comply with this rule. The Small Entity

Compliance Guide will be available on EPA’s Office of Policy’s Small Entity website at: 

http://www.epa.gov/rfa/compliance-guides.html, and on the Tier 3 website 

(http://www.epa.gov/otaq/tier3.htm) 60 days after publication of the final rule in the 

Federal Register.

D. Unfunded Mandates Reform Act

Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), 2 U.S.C. 1531-

1538, requires Federal agencies, unless otherwise prohibited by law, to assess the effects 

of their regulatory actions on State, local, and tribal governments and the private sector. 

This rule contains a Federal mandate that may result in expenditures of $100 million or 

more for State, local, and tribal governments, in the aggregate, or the private sector in any 

one year. Accordingly, EPA has prepared under section 202 of the UMRA a written 

statement of the cost-benefit analysis, which can be found in Section VIII of this 

preamble, and in Chapter 8 of the RIA.

Consistent with section 205, EPA has identified and considered a reasonable 

number of regulatory alternatives. These alternatives are described above in Sections IV, 

V, and IX of this preamble.

This rule is not subject to the requirements of section 203 of UMRA because it 

contains no regulatory requirements that might significantly or uniquely affect small 
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governments. The rule imposes no enforceable duty on any State, local or tribal 

governments. EPA has determined that this rule contains no regulatory requirements that 

might significantly or uniquely affect small governments. EPA has determined that this 

rule contains a Federal mandate that may result in expenditures of $100 million or more 

for the private sector in any one year, however EPA believes that the program being 

finalized today represents the least costly, and least burdensome approach to achieve the 

statutory requirements of the rule. The costs and benefits associated with this rule are 

discussed above in Section VIII of this preamble, and in Chapter 8 of the RIA, as 

required by section 202 of the UMRA.

E. Executive Order 13132: Federalism

This action does not have federalism implications. It will not have substantial 

direct effects on the States, on the relationship between the national government and the 

States, or on the distribution of power and responsibilities among the various levels of 

government, as specified in Executive Order 13132. Thus, Executive Order 13132 does 

not apply to this action. Although Executive Order 13132 does not apply to this rule, 

EPA did consult with representatives of various State and local governments in 

developing the rule. EPA also consulted with representatives from the National 

Association of Clean Air Agencies (NACAA, representing state and local air pollution 

officials), Northeast States for Coordinated Air Use Management (NESCAUM, the Clean 

Air Association of the Northeast States), and the Ozone Transport Commission (OTC, a 

multi-state organization created under the CAA responsible for advising EPA on 

transport issues and for developing and implementing regional solutions to the groundlevel ozone problem in the Northeast and Mid-Atlantic regions).

In the spirit of Executive Order 13132, and consistent with EPA policy to promote 

communications between EPA and State and local governments, EPA specifically

solicited comment on the proposed action from State and local officials. These 

comments are in the rulemaking docket and are summarized in the Summary and 

Analysis of Comments document.

F. Executive Order 13175: Consultation and Coordination with Indian Tribal 

Governments

This action does not have tribal implications, as specified in Executive Order 

13175 (65 FR 67249, November 9, 2000). This rule will be implemented at the Federal 

level and will impose compliance costs only on those in the gasoline production, 

distribution, and additive industry and in the engine and vehicle manufacturing industries. 

Tribal governments will be affected only to the extent they purchase and use regulated 

fuels, vehicles, and equipment. Thus, Executive Order 13175 does not apply to this 

action.
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Although Executive Order 13175 does not apply to this action, EPA specifically

solicited additional comment from tribal officials in developing this action (however we 

did not receive any comments).

G. Executive Order 13045: Protection of Children from Environmental Health 

Risks and Safety Risks

This action is subject to EO 13045 (62 FR 19885, April 23, 1997) because it is an 

economically significant regulatory action as defined by EO 12866, and EPA believes 

that the environmental health or safety risk addressed by this action may have a 

disproportionate effect on children. Accordingly, we have evaluated the environmental 

health or safety effects of air pollutants affected by the Tier 3 program on children. The 

results of this evaluation are contained in Section II.B and associated references.

Children are more susceptible than adults to many air pollutants because of 

differences in physiology, higher per body weight breathing rates and consumption, rapid 

development of the brain and bodily systems, and behaviors that increase chances for 

exposure. Even before birth, the developing fetus may be exposed to air pollutants 

through the mother that affect development and permanently harm the individual.

Infants and children breathe at much higher rates per body weight than adults, 

with infants under one year of age having a breathing rate up to five times that of 

adults.603 In addition, children breathe through their mouths more than adults and their 

nasal passages are less effective at removing pollutants, which leads to a higher 

deposition fraction in their lungs.604

Certain motor vehicle emissions present greater risks to children as well. Early

lifestages (e.g., children) are thought to be more susceptible to tumor development than 

adults when exposed to carcinogenic chemicals that act through a mutagenic mode of 

action.605 Exposure at a young age to these carcinogens could lead to a higher risk of 

developing cancer later in life. 

The adverse effects of individual air pollutants may be more severe for children, 

particularly the youngest age groups, than adults. The Integrated Science Assessments 

and Criteria Documents for a number of pollutants affected by this rule, including those 

 

603 U.S. Environmental Protection Agency. (2009). Metabolically-derived ventilation rates: a revised 

approach based upon oxygen consumption rates. Washington, DC: Office of Research and Development. 

EPA/600/R–06/129F. http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=202543.

604 Foos, B.; Marty, M.; Schwartz, J.; Bennet, W.; Moya, J.; Jarabek, A.M.; Salmon, A.G. (2008) Focusing 

on children’s inhalation dosimetry and health effects for risk assessment: an introduction. J Toxicol 

Environ Health 71A: 149–165.

605 U.S. Environmental Protection Agency. (2005). Supplemental guidance for assessing susceptibility

from early-life exposure to carcinogens. Washington, DC: Risk Assessment Forum. EPA/630/

R-03/003F. http://www.epa.gov/raf/publications/pdfs/childrens_supplement_final.pdf
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for NO2, SO2, PM, ozone and CO, describe children as a group with greater 

susceptibility. Section II.B.6 discusses a number of childhood health outcomes 

associated with proximity to roadways, including evidence for exacerbation of asthma 

symptoms and suggestive evidence for new onset asthma. In general, these studies do not 

identify the specific contaminants associated with adverse effects, instead addressing the 

near-roadway environment as one containing numerous exposures potentially associated 

with adverse health effects.

There is substantial evidence that people who live or attend school near major 

roadways are more likely to be of a minority race, Hispanic ethnicity, and/or low SES. 

Within these highly exposed groups, children’s exposure and susceptibility to health 

effects is greater than adults due to school-related and seasonal activities, behavior, and 

physiological factors.

Section III.C describes the ambient air quality changes resulting from the 

proposed standards, which represent levels to which the general population is exposed. 

Children are not expected to experience greater ambient concentrations of air pollutants 

than the general population. However, because of their greater susceptibility to air 

pollution and their increased time spent outdoors, it is likely that the proposed standards 

would have particular benefits for children’s health.

H. Executive Order 13211: Actions Concerning Regulations That Significantly 

Affect Energy Supply, Distribution, or Use

Executive Order 13211, “Actions Concerning Regulations That Significantly

Affect Energy Supply, Distribution, or Use” (66 FR 28355 (May 22, 2001)), requires 

EPA to prepare and submit a Statement of Energy Effects to the Administrator of the 

Office of Information and Regulatory Affairs, Office of Management and Budget, for 

certain actions identified as “significant energy actions.” Section 4(b) of Executive Order 

13211 defines “significant energy actions” as “any action by an agency (normally

published in the Federal Register) that promulgates or is expected to lead to the 

promulgation of a final rule or regulation, including notices of inquiry, advance notices of 

proposed rulemaking, and notices of proposed rulemaking: (1)(i) that is a significant 

regulatory action under Executive Order 12866 or any successor order, and (ii) is likely

to have a significant adverse effect on the supply, distribution, or use of energy; or (2) 

that is designated by the Administrator of the Office of Information and Regulatory

Affairs as a significant energy action.” Given the flexibilities being finalized for entities 

in the gasoline production and distribution system, we believe that these mitigate any

potential adverse effects on gasoline supply and distribution. Although EPA does not 

expect this rule to have significant adverse effects on the supply or distribution of 

gasoline, we have prepared a Statement of Energy Effects for this action as follows.

This rule’s potential effects on energy supply, distribution, or use have been 

analyzed and are further discussed above in:
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 Section V—fuel provisions of the rule and flexibilities, including hardship 

provisions.

 Section VII.B—estimated costs of the fuel program.

 Section X—economic impacts (specifically, Section X.C for fuel economic 

impacts, and Section X.D on employment impacts).

Given the estimated costs and impacts of the Tier 3 program, as discussed in this 

preamble and in the RIA, we do not expect this rule to have an adverse effect on the 

supply or distribution of gasoline. This judgment is based on a comparison of the 

estimated impacts of the Tier 3 program to those required for the Tier 2 program, and a 

review of gasoline supply during the phase-in of the Tier 2 gasoline sulfur program from 

2003 through 2011. As the Tier 2 program reduced gasoline sulfur from levels as high as 

450 ppm to a 30 ppm annual average, significant capital investments were required of 

many refineries to meet the 30 ppm sulfur standard. Both during and at the end of the 

Tier 2 phase-in, the U.S. gasoline markets did not experience a loss in gasoline supply as 

refiners utilized the flexibilities offered by the Tier 2 program to stagger investments and 

unit turnarounds/shutdowns to limit supply impacts. As discussed further in Chapter 5 of 

the RIA, we do not believe that the Tier 3 program will significantly affect U.S. gasoline 

supply and/or distribution. Comments received on the proposal estimating the impacts of 

an even more stringent program than Tier 3 support this conclusion606. Further, we do 

not believe that there are any reasonable alternatives to the control of sulfur in gasoline 

which would provide the level of reduction of emissions, considering our cost-benefit 

analyses, given by the sulfur reduction being finalized in this rule.

I. National Technology Transfer and Advancement Act

Section 12(d) of the National Technology Transfer and Advancement Act of 1995 

(“NTTAA”), Public Law No. 104-113 (15 U.S.C. 272 note) directs EPA to use voluntary

consensus standards in its regulatory activities unless to do so would be inconsistent with 

applicable law or otherwise impractical. Voluntary consensus standards are technical 

standards (e.g., materials specifications, test methods, sampling procedures, and business 

practices) that are developed or adopted by voluntary consensus standards bodies. 

NTTAA directs EPA to provide Congress, through OMB, explanations when the Agency

decides not to use available and applicable voluntary consensus standards.

This rulemaking involves technical standards. EPA has decided to update a 

number of regulations which already contain voluntary consensus standards to more 

recent versions of these standards. EPA is finalizing use of the ASTM International 

(ASTM) standards listed in Table XII-1 below. The standards may be obtained through 

the ASTM Web site (www.astm.org) or by calling ASTM at (610) 832–9585.

 

606 EPA-HQ-OAR-2011-0135-4276; Attachment 7.
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This rulemaking also involves environmental monitoring or measurement. 

Consistent with the Agency’s Performance Based Measurement System (“PBMS”), EPA 

has decided not to require the use of specific, prescribed analytic methods. Rather, the 

rule will allow the use of any method that meets the prescribed performance criteria. The 

PBMS approach is intended to be more flexible and cost-effective for the regulated 

community; it is also intended to encourage innovation in analytical technology and 

improved data quality. EPA is not precluding the use of any method, whether it 

constitutes a voluntary consensus standard or not, as long as it meets the performance 

criteria specified. Comments received on this approach are discussed in Section VI and 

in the Summary and Analysis of Comments document.

Table XII-1 Designated Analytical Test Methods for Gasoline and Diesel Fuel

Fuel Parameter Designated Analytical Method

Sulfur in gasoline ASTM D2622-10

Sulfur in butane ASTM D6667-10

500 ppm Sulfur Diesel Fuel ASTM D2622-10

Olefins in gasoline ASTM D1319-13

Reid vapor pressure (RVP) in gasoline ASTM D5191-12, with the following 

correlation equation:

RVP psi = (0.956 * X) - 0.347

RVP kPa = (0.956 * X) - 2.39

where:

X = total measured vapor pressure in psi or kPa

Distillation in gasoline ASTM D86-12

Benzene in gasoline ASTM D3606-10, except that instrument 

parameters shall be adjusted to ensure complete 

resolution of benzene, ethanol, and methanol 

peaks.

Aromatics in gasoline ASTM D5769-10, except that sample chilling 

requirements in section 8 of this standard are 

optional.

Oxygen and oxygenate content in 

gasoline

ASTM D5599-00 (2010)

Aromatics in diesel fuel ASTM D1319-13 

J. Executive Order 12898: Federal Actions to Address Environmental Justice in 

Minority Populations and Low-Income Populations

Executive Order (EO) 12898 (59 FR 7629 (Feb. 16, 1994)) establishes federal 

executive policy on environmental justice. Its main provision directs federal agencies, to 

the greatest extent practicable and permitted by law, to make environmental justice part 

of their mission by identifying and addressing, as appropriate, disproportionately high 
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and adverse human health or environmental effects of their programs, policies, and 

activities on minority populations and low-income populations in the United States.

EPA has determined that this final rule will not have disproportionately high and 

adverse human health or environmental effects on minority or low-income populations 

because it increases the level of environmental protection for all affected populations 

without having any disproportionately high and adverse human health or environmental 

effects on any population, including any minority or low-income population.

This final rule will reduce emissions from vehicles across the nation, both new 

vehicles (beginning in model year 2017, when the vehicle standards start to apply) and 

existing vehicles (as soon as the lower-sulfur gasoline becomes available in 2017). As a 

result, this rule increases the level of environmental protection for all populations. As 

discussed in Section III.C.7, there is evidence that minority populations and low-income 

populations live disproportionately near high-traffic roadways, where concentrations of 

many air pollutants are elevated. We expect this final rule to increase the level of 

environmental protection for these populations.

Thus, this final rule will not have a disproportionately high adverse human health 

or environmental effect on minority or low-income populations.

K. Congressional Review Act

The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the Small 

Business Regulatory Enforcement Fairness Act of 1996, generally provides that before a 

rule may take effect, the agency promulgating the rule must submit a rule report, which 

includes a copy of the rule, to each House of the Congress and to the Comptroller 

General of the United States. EPA will submit a report containing this rule and other 

required information to the U.S. Senate, the U.S. House of Representatives, and the 

Comptroller General of the United States prior to publication of the rule in the Federal 

Register. A major rule cannot take effect until 60 days after it is published in the Federal 

Register. This action is a “major rule” as defined by 5 U.S.C. 804(2). This rule will be 

effective on [INSERT DATE 60 DAYS AFTER PUBLICATION IN THE FEDERAL 

REGISTER].

XIII.Statutory Provisions and Legal Authority

Statutory authority for this action comes from sections 202, 203-209, 211, 213, 

216, and 301 of the Clean Air Act, 42 U.S.C. sections 7414, 7521, 7522-7525, 7541, 

7542, 7543, 7545, 7547, 7550, and 7601. Additional support for the procedural and 

compliance related aspects of this proposal, including the proposed recordkeeping 

requirements, comes from sections 114, 208, and 301(a) of the Clean Air Act, 42 U.S.C. 

sections 7414, 7542, and 7601(a).

List of Subjects
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40 CFR Part 79

Environmental protection, Administrative practice and procedure, Air pollution 

control, Confidential business information, Diesel fuel, Energy, Fuel additives, Gasoline, 

Motor vehicle pollution, Penalties, Petroleum, Reporting and recordkeeping 

requirements.

40 CFR Part 80

Environmental protection, Administrative practice and procedure, Air pollution 

control, Confidential Business Information, Diesel fuel, Fuel additives, Gasoline, 

Imports, Incorporation by reference, Labeling, Motor vehicle pollution, Penalties, 

Petroleum, Reporting and recordkeeping requirements.

40 CFR Part 85

Environmental protection, Administrative practice and procedure, Air pollution 

control, Confidential Business Information, Imports, Labeling, Motor vehicle pollution, 

Reporting and recordkeeping requirements, Research, Warranties.

40 CFR Part 86

Environmental protection, Administrative practice and procedure, Air pollution 

control, Confidential Business Information, Imports, Incorporation by reference, 

Labeling, Motor vehicle pollution, Reporting and recordkeeping requirements, 

Warranties.

40 CFR Part 600

Administrative practice and procedure, Electric power, Fuel economy, 

Incorporation by reference, Labeling, Reporting and recordkeeping requirements.

40 CFR Parts 1036 and 1037

Administrative practice and procedure, Air pollution control, Confidential 

business information, Environmental protection, Labeling, Motor vehicle pollution, 

Reporting and recordkeeping requirements, Warranties.

40 CFR Part 1039

Environmental protection, Administrative practice and procedure, Air pollution 

control, Confidential business information, Imports, Labeling, Penalties, Reporting and 

recordkeeping requirements, Warranties.

40 CFR Part 1042
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Environmental protection, Administrative practice and procedure, Air pollution 

control, Confidential business information, Imports, Labeling, Penalties, Vessels, 

Reporting and recordkeeping requirements, Warranties. 

40 CFR Part 1048

Environmental protection, Administrative practice and procedure, Air pollution 

control, Confidential business information, Imports, Labeling, Penalties, Reporting and 

recordkeeping requirements, Warranties.

40 CFR Part 1054

Environmental protection, Administrative practice and procedure, Air pollution 

control, Confidential business information, Imports, Labeling, Penalties, Reporting and 

recordkeeping requirements, Warranties.

40 CFR Parts 1065 and 1066

Environmental protection, Administrative practice and procedure, Incorporation 

by reference, Reporting and recordkeeping requirements, Research.

Dated: ____________________________

__________________________________

Gina McCarthy,

Administrator
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For the reasons set forth in the preamble, title 40, chapter I of the Code of Federal 

Regulations is amended as follows:

Part 79-REGISTRATION OF FUEL AND FUEL ADDITIVES

The authority citation for part 79 continues to read as follows:

Authority: 42 USC 7414, 7524, 7545, and 7601.

Section 79.5 is amended by revising paragraphs (a) and (b) introductory text to read as 

follows:

§ 79.5 Periodic reporting requirements.

(a) Fuel manufacturers. (1) For each calendar quarter (January through March, April 

through June, July through September, October through December) commencing after the 

date prescribed for a particular fuel in subpart D of this part, fuel manufacturers shall 

submit to the Administrator a report for each registered fuel showing the range of 

concentration of each additive reported under § 79.11(a) and the volume of such fuel 

produced in the quarter. Reports shall be submitted by the required deadline as shown in 

the following table:

Table 1 to § 79.5: Quarterly Reporting Deadlines

Calendar Quarter Time Period Covered Quarterly Report 

Deadline

Quarter 1 January 1 – March 31 June 1

Quarter 2 April 1 – June 30 September 1

Quarter 3 July 1 – September 30 December 1

Quarter 4 October 1 – December 31 March 31

(2) Fuel manufacturers shall submit to the Administrator a report annually for each 

registered fuel providing additional data and information as specified in §§ 79.32(c) and 

(d) and 79.33(c) and (d) in the designation of the fuel in subpart D of this part. Reports 

shall be submitted by March 31 for the preceding year, or part thereof, on forms supplied 

by the Administrator upon request. If the date prescribed for a particular fuel in subpart 

D of this part, or the later registration of a fuel is between October 1 and December 31, 

no report will be required for the period to the end of that year.

(b) Additive manufacturers. Additive manufacturers shall submit to the 

Administrator a report annually for each registered additive providing additional data and 

information as specified in § 79.31(c) and (d) in the designation of the additive in subpart 

D of this part. Additive manufacturers shall also report annually the volume of each 

additive produced. Reports shall be submitted by March 31 for the preceding year, or 
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part thereof, on forms supplied by the Administrator upon request. If the date prescribed 

for a particular additive in subpart D of this part, or the later registration of an additive is 

between October 1 and December 31, no report will be required for the period to the end 

of that year. These periodic reports shall not, however, be required for any additive that 

is:

* * * * *

Part 80-REGULATION OF FUEL AND FUEL ADDITIVES

The authority citation for part 80 continues to read as follows:

Authority: 42 U.S.C. 7414, 7521(l), 7545, and 7601(a).

Subpart A--[Amended] 

Section 80.2 is amended by:

a. Revising the introductory text and paragraphs (d), (w), (z), and (fff).

b. Adding paragraphs (vvv), (www), (xxx), (yyy), (zzz), (aaaa), (bbbb), (cccc), 

(dddd), (eeee), (ffff), (gggg), (hhhh), (iiii), (jjjj), and (kkkk).

§ 80.2 Definitions.

Definitions apply in this part as described in this section.

* * * * *

(d) Previously certified gasoline, or PCG, means conventional gasoline, reformulated 

gasoline, RBOB, or CBOB that previously has been included in a batch for purposes of 

complying with the standards of 40 CFR part 80 that apply to refiners and importers.

* * * * *

(w) Cetane index or “Calculated cetane index” is a number representing the ignition 

properties of diesel fuel oils from API gravity and mid-boiling point, as determined by 

ASTM D976.

* * * * *

(z) Aromatic content of diesel fuel is the aromatic hydrocarbon content in volume 

percent as follows:

(1) Through December 31, 2015, determine aromatic content of diesel fuel by ASTM 

D1319. 

(2) Beginning January 1, 2016, determine aromatic content of diesel fuel by a test 

method approved under § 80.47.

* * * * *

(fff) #1D means the distillate fuel classification relating to “No. 1-D” diesel fuels as 

described in ASTM D975.
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* * * * *

(vvv) Denatured fuel ethanol (DFE) means an alcohol of the chemical formula C2H6O 

which contains a denaturant to make it unfit for human consumption, that is produced or 

imported for use in motor gasoline, and that meets the requirements of § 80.1610.

(www) Oxygenate producer means any person who owns, leases, operates, controls, or 

supervises an oxygenate production facility.

(xxx) Oxygenate production facility means any facility where oxygenate including DFE 

designated as transportation fuel is produced.

(yyy) Oxygenate importer means a person who imports oxygenate from a foreign 

country into the United States (including the Commonwealth of Puerto Rico, the Virgin 

Islands, Guam, American Samoa, and the Northern Mariana Islands).

(zzz) Oxygenate import facility means any facility where oxygenate including DFE 

designated as transportation fuel is imported into the United States.

(aaaa) CBOB means gasoline blendstock that could become conventional gasoline solely

upon the addition of oxygenate.

(bbbb) Natural gas liquids (NGL) means the components of natural gas (primarily 

propane, butane, pentane, hexane, and heptane) that are separated from the gas state in 

the form of liquids in facilities such as a natural gas production facility, a gas processing 

plant, a natural gas pipeline, or a refinery or similar facility. The higher temperature 

boiling components of NGL are sometimes referred to as “natural gasoline”.

(cccc) Natural gas means a mixture of hydrocarbon gases that occurs with petroleum 

deposits, principally methane together with varying quantities of ethane, propane, butane, 

and other gases.

(dddd) Butane blender means a refiner or refinery that produces gasoline by blending 

butane that meets the quality specifications in § 80.82 with conventional gasoline, 

CBOB, reformulated gasoline, or RBOB, and that uses the streamlined provisions in § 

80.82 to meet some of the applicable sampling and testing requirements.

(eeee) Pentane blender means a refiner or refinery that produces gasoline by blending 

pentane that meets the quality specifications in § 80.86 with conventional gasoline, 

CBOB, reformulated gasoline, or RBOB, and that uses the streamlined provisions in § 

80.85 to meet some of the applicable sampling and testing requirements.

(ffff) Blender-commercial grade pentane means pentane that meets the requirements in 

§ 80.86(a)(3) for pentane for use by a pentane blender pursuant to the requirements of § 

80.85.
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(gggg) Blender-non-commercial grade pentane means pentane that meets the 

requirements in § 80.86(a)(4) for pentane for use by a pentane blender pursuant to the 

requirements of § 80.85.

(hhhh) Blender-grade pentane means pentane that meets the requirements for commercial 

grade pentane or non-commercial grade pentane pursuant to the requirements of § 80.86.

(iiii) Ethanol denaturant means previously certified gasoline (including previously

certified blendstocks for oxygenate blending), gasoline blendstocks, or natural gasoline 

liquids that are added to neat (un-denatured) ethanol to make it unfit for human 

consumption in accordance with the requirements of the Alcohol and Tobacco Tax and 

Trade Bureau of the U.S. Treasury Department.(jjjj) [Reserved]

(kkkk) Materials incorporated by reference. The published materials identified in this 

section are incorporated by reference into this section with the approval of the Director of 

the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. To enforce any edition 

other than that specified in this section, a document must be published in the Federal 

Register and the material must be available to the public. All approved materials are 

available for inspection at the Air and Radiation Docket and Information Center (Air 

Docket) in the EPA Docket Center (EPA/ DC) at Rm. 3334, EPA West Bldg., 1301

Constitution Ave. NW., Washington, DC. The EPA/DC Public Reading Room hours of 

operation are 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. 

The telephone number of the EPA/DC Public Reading Room is (202) 566–1744, and the 

telephone number for the Air Docket is (202) 566–1742. These approved materials are 

also available for inspection at the National Archives and Records Administration 

(NARA). For information on the availability of this material at NARA, call (202) 741–

6030 or go to http:// www.archives.gov/federal_register/ code_of_federal_regulations/ 

ibr_locations.html. In addition, these materials are available from the sources listed 

below.

(1) ASTM International material. The following standards are available from ASTM 

International, 100 Barr Harbor Dr., P.O. Box C700, West Conshohocken, PA 19428-

2959, (877) 909–ASTM, or http://www.astm.org:

(i) ASTM D975-13a, Standard Specification for Diesel Fuel Oils, approved 

December 1, 2013.

(ii) ASTM D976-06 (Reapproved 2011), Standard Test Method for Calculated Cetane 

Index of Distillate Fuels, approved October 1, 2011.

(iii) ASTM D1319-13, Standard Test Method for Hydrocarbon Types in Liquid 

Petroleum Products by Fluorescent Indicator Adsorption, approved May 1, 2013.

(2) [Reserved]

Section 80.8 is revised to read as follows:
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§ 80.8 Sampling methods for gasoline, diesel fuel, fuel additives, and renewable 

fuels.

The sampling methods specified in this section shall be used to collect samples of 

gasoline, diesel fuel, blendstocks, fuel additives and renewable fuels for purposes of 

determining compliance with the requirements of this part.

(a) Manual sampling. Manual sampling of tanks and pipelines shall be performed 

according to the applicable procedures specified in ASTM D4057. 

(b) Automatic sampling. Automatic sampling of petroleum products in pipelines 

shall be performed according to the applicable procedures specified in ASTM D4177.

(c) Sampling and sample handling for volatility measurement. Samples to be 

analyzed for Reid Vapor Pressure (RVP) shall be collected and handled according to the 

applicable procedures specified in ASTM D5842.

(d) Sample compositing. Composite samples shall be prepared using the applicable 

procedures specified in ASTM D5854.

(e) Materials incorporated by reference. The published materials identified in this 

section are incorporated by reference into this section with the approval of the Director of 

the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. To enforce any edition 

other than that specified in this section, a document must be published in the Federal 

Register and the material must be available to the public. All approved materials are 

available for inspection at the Air and Radiation Docket and Information Center (Air 

Docket) in the EPA Docket Center (EPA/ DC) at Rm. 3334, EPA West Bldg., 1301

Constitution Ave. NW., Washington, DC. The EPA/DC Public Reading Room hours of 

operation are 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. 

The telephone number of the EPA/DC Public Reading Room is (202) 566–1744, and the 

telephone number for the Air Docket is (202) 566–1742. These approved materials are 

also available for inspection at the National Archives and Records Administration 

(NARA). For information on the availability of this material at NARA, call (202) 741–

6030 or go to http:// www.archives.gov/federal_register/ code_of_federal_regulations/ 

ibr_locations.html. In addition, these materials are available from the sources listed 

below.

(1) ASTM International material. The following standards are available from ASTM 

International, 100 Barr Harbor Dr., P.O. Box C700, West Conshohocken, PA 19428-

2959, (877) 909–ASTM, or http://www.astm.org:

(i) ASTM D4057-12, Standard Practice for Manual Sampling of Petroleum and 

Petroleum Products, approved December 1, 2012.

(ii) ASTM D4177-95 (Reapproved 2010), Standard Practice for Automatic Sampling 

of Petroleum and Petroleum Products, approved May 1, 2010.
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(iii) ASTM D5842-04 (Reapproved 2009), Standard Practice for Sampling and 

Handling of Fuels for Volatility Measurement, approved July 1, 2009.

(iv) ASTM D5854-96 (Reapproved 2010), Standard Practice for Mixing and Handling 

of Liquid Samples of Petroleum and Petroleum Products, approved May 1, 2010.

(2) [Reserved]

Subpart D--[Amended] 

Section 80.46 is amended by revising the section heading and paragraphs (a), (b), (c), (d), 

(e), (f)(1), (f)(3)(i), (g), and (h) to read as follows:

§ 80.46 Measurement of reformulated gasoline and conventional gasoline fuel 

parameters.

(a) Sulfur. Sulfur content of gasoline and butane must be determined by use of the 

following methods:

(1) Through December 31, 2015, the sulfur content of gasoline must be determined 

by ASTM D2622 or by one of the alternative test methods specified in paragraph (a)(3) 

of this section. Beginning January 1, 2016, the sulfur content of gasoline must be 

determined by a test method approved under § 80.47.

(2) Through December 31, 2015, the sulfur content of butane must be determined by

ASTM D6667 or by one of the alternative test methods specified in paragraph (a)(4) of 

this section. 

(3) Through December 31, 2015, any refiner or importer may use ASTM D3120, 

ASTM D5453, ASTM D6920, or ASTM D7039 for determining the sulfur content of 

gasoline provided the refiner or importer test result is correlated with the method 

specified in paragraph (a)(1) of this section:

(4) Beginning January 1, 2016, the sulfur content of butane must be determined by a 

test method approved under § 80.47. Through December 31, 2015, any refiner or 

importer may determine the sulfur content of butane using ASTM D4468 or ASTM 

D3246; provided the refiner or importer test result is correlated with the method specified 

in paragraph (a)(2) of this section.

(b) Olefins. Olefin content must be determined by use of the following methods:

(1) Through December 31, 2015, olefin content must be determined using ASTM 

D1319. Beginning January 1, 2016, the olefin content of gasoline may be determined by 

a test method approved under § 80.47.

(2) Through December 31, 2015, any refiner or importer may determine olefin 

content using ASTM D6550 for purposes of meeting any testing requirements involving 

olefin content, provided that the refiner or importer test result is correlated with the 

method specified in paragraph (b)(1) of this section on a site-specific basis, in order to 

achieve an unbiased prediction of the result in volume percent, for the method specified 

in paragraph (b)(1) of this section.

* * * * *
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(c) Reid Vapor Pressure (RVP). (1) Through December 31, 2015, Reid Vapor 

Pressure must be determined using ASTM D5191, except the following correction 

equation must be used:

RVP psi = (0.956 * X) – 0.347

RVP kPa = 0.956 * X) – 2.39

Where:

X = Total measured vapor pressure, in psi or kPa.

(2) Beginning January 1, 2016, RVP may be determined by a test method approved 

under § 80.47, except as provided in paragraph (c)(2)(i) of this section.

(i) For reporting purposes, the RVP test result computed from § 80.47 must continue 

to utilize the RVP correction equation in paragraph (c)(1) of this section.

(ii) [Reserved]

(d) Distillation. Through December 31, 2015, distillation parameters must be 

determined using ASTM D86. Beginning January 1, 2016, the distillation parameters 

may be determined by a test method approved under § 80.47.

(e) Benzene. Through December 31, 2015, benzene content must be determined 

using ASTM D3606, except that instrument parameters shall be adjusted to ensure 

complete resolution of the benzene, ethanol and methanol peaks because ethanol and 

methanol may cause interference with ASTM D3606 when present. Beginning January

1, 2016, the benzene content may be determined by a test method approved under § 

80.47.

(f)(1) Through December 31, 2015, aromatic content must be determined using ASTM 

D5769, except the sample chilling requirements in section 8 of this standard method are 

optional. Beginning January 1, 2016, the aromatic content may be determined by a test 

method approved under § 80.47.

* * * * *

(3)(i) Through December 31, 2015, any refiner or importer may determine aromatics 

content using ASTM D1319 for the purposes of meeting any test requirement involving 

aromatic content; provided that–

* * * * *

(g) Oxygen and oxygenate content analysis. (1) Through December 31, 2015, oxygen 

and oxygenate content must be determined using ASTM D5599. Beginning January 1, 

2016, oxygen and oxygenate content may be determined by a test method approved under 

§ 80.47.

(2) Through December 31, 2015, when oxygenates present are limited to MTBE, 

ETBE, TAME, DIPE, tertiary-amyl alcohol and C1 to C4 alcohols, any refiner, importer, 

or oxygenate blender may determine oxygen and oxygen content using ASTM D4815 for 

purposes of meeting any testing requirement; provided that the refiner or importer test 

result is correlated with the method specified in paragraph (g)(1) of this section.
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* * * * *

(h) Materials incorporated by reference. The published materials identified in this 

section are incorporated by reference into this section with the approval of the Director of 

the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. To enforce any edition 

other than that specified in this section, a document must be published in the Federal 

Register and the material must be available to the public. All approved materials are 

available for inspection at the Air and Radiation Docket and Information Center (Air 

Docket) in the EPA Docket Center (EPA/ DC) at Rm. 3334, EPA West Bldg., 1301

Constitution Ave. NW., Washington, DC. The EPA/DC Public Reading Room hours of 

operation are 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. 

The telephone number of the EPA/DC Public Reading Room is (202) 566–1744, and the 

telephone number for the Air Docket is (202) 566–1742. These approved materials are 

also available for inspection at the National Archives and Records Administration 

(NARA). For information on the availability of this material at NARA, call (202) 741–

6030 or go to http:// www.archives.gov/federal_register/ code_of_federal_regulations/ 

ibr_locations.html. In addition, these materials are available from the sources listed 

below.

(1) ASTM International material. The following standards are available from ASTM 

International, 100 Barr Harbor Dr., P.O. Box C700, West Conshohocken, PA 19428-

2959, (877) 909–ASTM, or http://www.astm.org:

(i) ASTM D86-12, Standard Test Method for Distillation of Petroleum Products at 

Atmospheric Pressure, approved December 1, 2012.

(ii) ASTM D1319-13, Standard Test Method for Hydrocarbon Types in Liquid 

Petroleum Products by Fluorescent Indicator Adsorption, approved May 1, 2013.

(iii) ASTM D2622-10, Standard Test Method for Sulfur in Petroleum Products by

Wavelength Dispersive X-ray Fluorescence Spectrometry, approved February 15, 2010.

(iv) ASTM D3120-08, Standard Test Method for Trace Quantities of Sulfur in Light 

Liquid Petroleum Hydrocarbons by Oxidative Microcoulometry, approved December 15, 

2008.

(v) ASTM D3246-11, Standard Test Method for Sulfur in Petroleum Gas by 

Oxidative Microcoulometry, approved June 1, 2011.

(vi) ASTM D3606-10, Standard Test Method for Determination of Benzene and 

Toluene in Finished Motor and Aviation Gasoline by Gas Chromatography, approved 

October 1, 2010.

(vii) ASTM D4468-85 (Reapproved 2011), Standard Test Method for Total Sulfur in 

Gaseous Fuels by Hydrogenolysis and Rateometric Colorimetry, approved November 1, 

2011.

(viii) ASTM D4815-13, Standard Test Method for Determination of MTBE, ETBE, 

TAME, DIPE, tertiary-Amyl Alcohol and C1 to C4 Alcohols in Gasoline by Gas 

Chromatography, approved October 1, 2013.

(ix) ASTM D5191-13, Standard Test Method for Vapor Pressure of Petroleum 

Products (Mini Method) , approved December 1, 2013.
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(x) ASTM D5453-12, Standard Test Method for Determination of Total Sulfur in 

Light Hydrocarbons, Spark Ignition Engine Fuel, Diesel Engine Fuel, and Engine Oil by

Ultraviolet Fluorescence, approved November 1, 2012.

(xi) ASTM D5599-00 (Reapproved 2010), Standard Test Method for Determination of 

Oxygenates in Gasoline by Gas Chromatography and Oxygen Selective Flame Ionization 

Detection, approved October 1, 2010.

(xii) ASTM D5769-10, Standard Test Method for Determination of Benzene, Toluene, 

and Total Aromatics in Finished Gasolines by Gas Chromatography/Mass Spectrometry, 

approved May 1, 2010.

(xiii) ASTM D6550-10, Standard Test Method for Determination of Olefin Content of 

Gasolines by Supercritical-Fluid Chromatography, approved October 1, 2010.

(xiv) ASTM D6667-10, Standard Test Method for Determination of Total Volatile 

Sulfur in Gaseous Hydrocarbons and Liquefied Petroleum Gases by Ultraviolet 

Fluorescence, approved October 1, 2010.

(xv) ASTM D6920-13, Standard Test Method for Total Sulfur in Naphthas, Distillates, 

Reformulated Gasolines, Diesels, Biodiesels, and Motor Fuels by Oxidative Combustion 

and Electrochemical Detection, approved September 15, 2013.

(xvi) ASTM D7039-13, Standard Test Method for Sulfur in Gasoline, Diesel Fuel, Jet 

Fuel, Kerosine, Biodiesel, Biodiesel Blends, and Gasoline-Ethanol Blends by

Monochromatic Wavelength Dispersive X-ray Fluorescence Spectrometry, approved 

September 15, 2013.

(2) [Reserved]

* * * * *

Section 80.47 is added to read as follows:

§80.47 Performance-based Analytical Test Method Approach.

All sample handling, testing procedures, and tests must be conducted using good 

laboratory practices.

(a) Definitions. As used in this subpart 80:

(1) Performance-based Analytical Test Method Approach means a measurement 

system based upon established performance criteria for accuracy and precision with use 

of analytical test methods. As used in this subpart, this is a measurement system used by

laboratories to demonstrate that a particular analytical test method is acceptable for 

demonstrating compliance.

(2) Accuracy means the closeness of agreement between an observed value from a 

single test measurement and an accepted reference value. 

(3) Precision means the degree of agreement in a set of measurements performed on 

the same property of identical test material.
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(4) Absolute fuel parameter means a fuel parameter for which a gravimetric standard 

is practical to construct and use. Sulfur content of gasoline, butane, or diesel fuel are 

examples of an absolute fuel parameter.

(5) Gravimetric standard means a test material made by adding a carefully weighed 

quantity of the analyte to a measured quantity of another substance known not to contain 

any of the analyte, resulting in a solution with an accurately known concentrate of the 

analyte. 

(6) Consensus named fuels are homogeneous quantities of fuel that have been 

analyzed by a number of different laboratories (by sending around small samples). The 

average concentration of some parameter of interest across all of the different laboratories 

is then used as the “consensus name” for that material.

(7) Locally-named reference materials are gasoline or diesel fuels that are usually

from the regular production of the facility where they are used in laboratory quality 

control efforts and have been analyzed using the designated method (either by the 

facility’s lab or by a referee lab) to obtain an estimate of their concentration.

(8) Method-defined fuel parameter means a fuel parameter for which an EPAprescribed primary test method or designated method defines the regulatory standard. 

Examples of method-defined fuel parameters include olefin content in gasoline, Reid 

vapor pressure (RVP) of gasoline, distillation parameters of gasoline, benzene content of 

gasoline, aromatic content of gasoline and diesel fuel, and oxygen/oxygenates content of 

gasoline. 

(9) Reference installations are designated test method installations that are used to 

qualify the accuracy of other method-defined parameter instruments. Reference 

installations of the designated test method will be used to evaluate the accuracy of other 

method-defined alternative test methods and to establish correlation equations if 

necessary.

(10) Correlation equation is a correction equation as determined by the use of ASTM 

D6708. This standard practice determines whether the comparison between the 

alternative test method and the designated test method is a null result. If the comparison 

is not null, then the standard practice provides for a correlation equation that predicts 

designated test method results from the applicable method-defined alternative test 

method. 

(11) Statistical quality control (SQC) means a planned system of activities whose 

purpose is to provide a level of quality that meets the needs of compliance with the 

standards of this part. This subpart prescribes specific SQC requirements for both 

absolute and method driven fuel parameters for both voluntary and non-voluntary

consensus-based standards bodies. 

(12) Voluntary consensus-based standards body (VCSB) means a domestic or 

international organization that plans, develops, establishes, or coordinates voluntary

consensus standards using agreed-upon procedures and which possesses the attributes of 

openness, balance of interest, due process, and consensus, as explained in OMB Circular 

A-119 and the National Technology Transfer and Advancement Act of 1995, P.L. 104-

113, sec. 12(d).
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(13) Non-voluntary consensus-based standards body (non-VCSB) means a domestic or 

international regulated party that has developed a proprietary analytical test method that 

has not been adopted by a VCSB organization.

(b) Precision and accuracy criteria for approval for the absolute fuel parameter of 

gasoline sulfur.

(1) Precision. Beginning January 1, 2016, for motor vehicle gasoline, gasoline 

blendstock, and gasoline fuel additives subject to the gasoline sulfur standard at §80.195 

and §80.1603, the maximum allowable standard deviation computed from the results of a 

minimum of 20 tests made over 20 days (seven or fewer tests per week and two or fewer 

tests per day) on samples using good laboratory practices taken from a single 

homogeneous commercially available gasoline must be less than or equal to 1.5 times the 

repeatability “r” divided by 2.77, where “r” equals the ASTM repeatability of ASTM 

D7039 (Example: A 10ppm sulfur gasoline sample: maximum allowable standard 

deviation of 20 tests≤1.5*(1.75ppm/2.77)=0.95 ppm). The 20 results must be a series of 

tests with a sequential record of analysis and no emissions. A laboratory facility may

exclude a given sample or test result only if the exclusion is for a valid reason under good 

laboratory practices and it maintains records regarding the sample and test results and the 

reason for excluding them.

(2) Accuracy. Beginning January 1, 2016, for motor vehicle gasoline, gasoline 

blendstock, and gasoline fuel additives subject to the gasoline sulfur standard at §§80.195 

and 80.1603:

(i) The arithmetic average of a continuous series of at least 10 tests performed using 

good laboratory practices on a commercially available gravimetric sulfur standard in the 

range of 1-10 ppm shall not differ from the accepted reference value (ARV) of the 

standard by more than 0.71 ppm sulfur;

(ii) The arithmetic average of a continuous series of at least 10 tests performed using 

good laboratory practices on a commercially available gravimetric sulfur standard in the 

range of 10-20 ppm shall not differ from the ARV of the standard by more than 1.00 ppm 

sulfur; and

(iii) In applying the tests of paragraphs (b)(2)(i) and (ii) of this section, individual test 

results shall be compensated for any known chemical interferences using good laboratory

practices.

(3) The test method specified at §80.46(a)(1) and in use prior to [INSERT DATE 6 

MONTHS PRIOR TO PUBLICATION IN THE FEDERAL REGISTER] is exempt 

from the requirements of paragraphs (b)(1) and (2) of this section.

(c) Precision and accuracy criteria for approval of the absolute fuel parameter of 

sulfur in butane.

(1) Precision. Beginning January 1, 2016, for butane subject to the butane sulfur 

standard at §§80.82, 80.195, 80.340(b) and 80.1603, the maximum allowable standard 

deviation computed from the results of a minimum of 20 tests made over 20 days (tests 

into no fewer than five batches or fewer tests each, with only one such batch allowed per 

day over the minimum of 20 days) on samples using good laboratory practices taken from 
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a single homogeneous commercially available butane must be less than or equal to 1.5 

times the repeatability (r) divided by 2.77, where “r” equals the ASTM repeatability of 

ASTM D6667 (Example: A 80 ppm sulfur butane sample: maximum allowable standard 

deviation of 20 tests≤1.5*(9.22ppm/2.77)=4.99 ppm). The 20 results must be a series of 

tests with a sequential record of analysis and no emissions. A laboratory facility may

exclude a given sample or test result only if the exclusion is for a valid reason under good 

laboratory practices and it maintains records regarding the sample and test results and the 

reason for excluding them. 

(2) Accuracy. Beginning January 1, 2016, for butane subject to the butane sulfur 

standard at §§80.82, 80.195, 80.340(b) and 80.1603–

(i) The arithmetic average of a continuous series of at least 10 tests performed using 

good laboratory practices on a commercially available gravimetric sulfur standard in the 

range of 70-80 ppm, say 75 ppm, shall not differ from the accepted reference value 

(ARV) of the standard by more than 4.68 ppm sulfur;

(ii) The arithmetic average of a continuous series of at least 10 tests performed using 

good laboratory practices on a commercially available gravimetric sulfur standard in the 

range of 80-90 ppm, say 85 ppm, shall not differ from the accepted reference value 

(ARV) of the standard by more than 5.31 ppm sulfur; and

(iii) In applying the tests of paragraphs (c)(2)(i) and (ii) of this section, individual test 

results shall be compensated for any known chemical interferences using good laboratory

practices.

(3) The test method specified at §80.46(a)(2) and in use prior to [INSERT DATE 6 

MONTHS PRIOR TO PUBLICATION IN THE FEDERAL REGISTER] is exempt 

from the requirements of paragraphs (c)(1) and (2) of this section.

(d) Precision criteria for approval of the method defined fuel parameter of olefins in 

gasoline.

(1) Precision. Beginning January 1, 2016, for motor vehicle gasoline, gasoline 

blendstock, and gasoline fuel additives subject to the gasoline standards of this part, the 

maximum allowable standard deviation computed from the results of a minimum of 20 

tests made over 20 days (tests may be arranged into no fewer than five batches or fewer 

tests each, with only one such batch allowed per day over the minimum of 20 days) on 

samples using good laboratory practices taken from a single homogeneous commercially 

available gasoline must be less than or equal to 0.3 times the reproducibility (R) , where 

“R” equals the ASTM reproducibility of ASTM D1319 (Example: A gasoline containing 

9 Vol% olefins: maximum allowable standard deviation of 20 tests ≤0.3*(3.06 Vol%) = 

0.92 Vol%). The 20 results must be a series of tests with a sequential record of analysis 

and no emissions. A laboratory facility may exclude a given sample or test result only if 

the exclusion is for a valid reason under good laboratory practices and it maintains 

records regarding the sample and test results and the reason for excluding them.(2)

The test method specified at §80.46(b)(1) and in use prior to [INSERT DATE 6 

MONTHS PRIOR TO PUBLICATION IN THE FEDERAL REGISTER] is exempt 

from the requirements of paragraph (d)(1) of this section.
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(e) Precision criteria for approval of the method defined fuel parameter of aromatics 

in gasoline.

(1) Precision. Beginning January 1, 2016, for motor vehicle gasoline, gasoline 

blendstock, and gasoline fuel additives subject to the gasoline standards of this part, the 

maximum allowable standard deviation computed from the results of a minimum of 20 

tests made over 20 days (tests may be arranged into no fewer than five batches or fewer 

tests each, with only one such batch allowed per day over the minimum of 20 days) on 

samples using good laboratory practices taken from a single homogeneous commercially 

available gasoline must be less than or equal to 0.3 times the reproducibility (R), where 

“R” equals the ASTM reproducibility of ASTM D1319-13 (Example: A gasoline 

containing 32Vol% aromatics: maximum allowable standard deviation of 20 tests 

≤0.3*(3.7 Vol%) = 1.11Vol%). The 20 results must be a series of tests with a sequential 

record of analysis and no emissions. A laboratory facility may exclude a given sample or 

test result only if the exclusion is for a valid reason under good laboratory practices and it 

maintains records regarding the sample and test results and the reason for excluding 

them.

(2) The test method specified at §80.46(f)(1) and in use prior to [INSERT DATE 6 

MONTHS PRIOR TO PUBLICATION IN THE FEDERAL REGISTER] is exempt 

from the requirements of paragraph (e)(1) of this section.

(f) Precision criteria for approval of the method defined fuel parameter of oxygen 

and oxygenate content in gasoline.

(1) Precision. Beginning January 1, 2016, for motor vehicle gasoline, gasoline 

blendstock, and gasoline fuel additives subject to the gasoline standards of this part, the 

maximum allowable standard deviation computed from the results of a minimum of 20 

tests made over 20 days (tests may be arranged into no fewer than five batches or fewer 

tests each, with only one such batch allowed per day over the minimum of 20 days) on 

samples using good laboratory practices taken from a single homogeneous commercially 

available gasoline must be less than or equal to 0.3 times the reproducibility (R), where 

“R” equals the ASTM reproducibility of ASTM 5599 (Example: A gasoline containing 

3Mass% total oxygen: maximum allowable standard deviation of 20 tests ≤0.3*(0.32 

Mass%) = 0.10 Mass%). The 20 results must be a series of tests with a sequential record 

of analysis and no emissions. A laboratory facility may exclude a given sample or test 

result only if the exclusion is for a valid reason under good laboratory practices and it 

maintains records regarding the sample and test results and the reason for excluding 

them.

(2) The test method specified at §80.46(g)(1) and in use prior to [INSERT DATE 6 

MONTHS PRIOR TO PUBLICATION IN THE FEDERAL REGISTER] is exempt 

from the requirements of paragraph (f)(1) of this section.

(g) Precision criteria for approval of the method defined fuel parameter of Reid 

Vapor Pressure (RVP) in gasoline.

(1) Precision. Beginning January 1, 2016, for motor vehicle gasoline, gasoline 

blendstock, and gasoline fuel additives subject to the gasoline standards of this part and 
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volatility standards at §80.27, the maximum allowable standard deviation computed from 

the results of a minimum of 20 tests made over 20 days (tests may be arranged into no 

fewer than five batches or fewer tests each, with only one such batch allowed per day

over the minimum of 20 days) on samples using good laboratory practices taken from a 

single homogeneous commercially available gasoline must be less than or equal to 0.3 

times the reproducibility (R), where “R” equals the ASTM reproducibility of ASTM 

5191 (Example: A gasoline having a RVP of 6.8psi: maximum allowable standard 

deviation of 20 tests ≤0.3*(0.40psi) = 0.12 psi). The 20 results must be a series of tests 

with a sequential record of analysis and no emissions. A laboratory facility may exclude 

a given sample or test result only if the exclusion is for a valid reason under good 

laboratory practices and it maintains records regarding the sample and test results and the 

reason for excluding them.

(2) The test method specified at §80.46(c)(1) and in use prior to [INSERT DATE 6 

MONTHS PRIOR TO PUBLICATION IN THE FEDERAL REGISTER] is exempt 

from the requirements of paragraph (g)(1) of this section.

(h) Precision criteria for approval of the method defined fuel parameter of gasoline 

distillation.

(1) Precision. Beginning January 1, 2016, for motor vehicle gasoline, gasoline 

blendstock, and gasoline fuel additives subject to the gasoline standards of this part, the 

maximum allowable standard deviation computed from the results of a minimum of 20 

tests made over 20 days (tests may be arranged into no fewer than five batches or fewer 

tests each, with only one such batch allowed per day over the minimum of 20 days) on 

samples using good laboratory practices taken from a single homogeneous commercially 

available gasoline must be less than or equal to 0.3 times the reproducibility (R), where 

“R” equals the ASTM reproducibility of ASTM D86 for the initial boiling point, E10, 

E50, E90 and final boiling point. (Example: A gasoline having an initial boiling point of 

26 °C and a final boiling point of 215 °C: maximum allowable standard deviation of 20 

tests for initial boiling point ≤0.3*(8.5 °C) = 2.55 °C, maximum allowable standard 

deviation of 20 tests for E10 ≤0.3*(3.0+2.64*Sc)°C, maximum allowable standard 

deviation of 20 tests for E50 ≤0.3*(2.9+3.97*Sc)°C, maximum allowable standard 

deviation of 20 tests for E90t ≤0.3*(2.0+2.53*Sc) °C, and maximum allowable standard 

deviation of 20 tests for final boiling point ≤0.3*(10.5°C) = 3.15°C ), where Sc is the 

average slope (or rate of change) of the gasoline distillation curve as calculated in 

accordance with section 13.5 of ASTM D86. The 20 results must be a series of tests with 

a sequential record of analysis and no emissions. A laboratory facility may exclude a 

given sample or test result only if the exclusion is for a valid reason under good 

laboratory practices and it maintains records regarding the sample and test results and the 

reason for excluding them.

(2) The test method specified at §80.46(d)(1) and in use prior to [INSERT DATE 6 

MONTHS PRIOR TO PUBLICATION IN THE FEDERAL REGISTER] is exempt 

from the requirements of paragraph (h)(1) of this section.
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(i) Precision criteria for approval of the method defined fuel parameter of benzene in 

gasoline.

(1) Precision. Beginning January 1, 2016, for motor vehicle gasoline, gasoline 

blendstock, and gasoline fuel additives subject to the gasoline standards of this part and 

MSAT2 standards at §§80.41, 80.101, 80.1230, the maximum allowable standard 

deviation computed from the results of a minimum of 20 tests made over 20 days (tests 

may be arranged into no fewer than five batches or fewer tests each, with only one such 

batch allowed per day over the minimum of 20 days) on samples using good laboratory

practices taken from a single homogeneous commercially available gasoline must be less 

than or equal to 0.3 times the reproducibility (R), where “R” equals the ASTM 

reproducibility of ASTM D3606 (Example: A gasoline having a 1Vol% benzene: 

maximum allowable standard deviation of 20 tests ≤0.3*(0.18 Vol%) = 0.054Vol%). The 

20 results must be a series of tests with a sequential record of analysis and no emissions. 

A laboratory facility may exclude a given sample or test result only if the exclusion is for 

a valid reason under good laboratory practices and it maintains records regarding the 

sample and test results and the reason for excluding them.

(2) The test method specified at §80.46(e)(1) and in use prior to [INSERT DATE 6 

MONTHS PRIOR TO PUBLICATION IN THE FEDERAL REGISTER] is exempt 

from the requirements of paragraph (i)(1) of this section.

(j) Precision criteria for approval of the method defined fuel parameter of aromatics 

in diesel.

(1) Precision. Beginning January 1, 2016, for motor vehicle gasoline, gasoline 

blendstock, and gasoline fuel additives subject to the motor vehicle diesel standards at 

§80.520, the maximum allowable standard deviation computed from the results of a 

minimum of 20 tests made over 20 days (tests may be arranged into no fewer than five 

batches or fewer tests each, with only one such batch allowed per day over the minimum 

of 20 days) on samples using good laboratory practices taken from a single homogeneous 

commercially available gasoline must be less than or equal to 0.3 times the 

reproducibility (R), where “R” equals the ASTM reproducibility of ASTM D1319 

(Example: A diesel fuel containing 35 Vol% aromatics: maximum allowable standard 

deviation of 20 tests ≤0.3*(3.7 Vol%) = 1.11Vol%). The 20 results must be a series of 

tests with a sequential record of analysis and no emissions. A laboratory facility may

exclude a given sample or test result only if the exclusion is for a valid reason under good 

laboratory practices and it maintains records regarding the sample and test results and the 

reason for excluding them.

(2) The test method specified at §80.2(z) and in use prior to [INSERT DATE 6 

MONTHS PRIOR TO PUBLICATION IN THE FEDERAL REGISTER] is exempt 

from the requirements of paragraph (j)(1) of this section.

(k) Criteria for designated test method reference installations used to qualify the 

accuracy of other method-defined parameter instruments.
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(1) Beginning January 1, 2016, for a single laboratory test facility qualifying a 

method defined alternative test method, the reference installation of the method-defined 

fuel parameter for the applicable designated test method must have precision equal to 0.3 

times the reproducibility (R) of the method-defined fuel parameter’s designated test 

method, where “R” is the reproducibility of the designated test method.

(i) For olefins in gasoline, see §80.47(d)(1).

(ii) For aromatics in gasoline, see §80.47(e)(1).

(iii) For oxygen and oxygenate content of gasoline, see §80.47(f)(1).

(iv) For Reid Vapor Pressure (RVP) of gasoline, see §80.47(g)(1).

(v) For gasoline distillation, see §80.47(h)(1).

(vi) For benzene in gasoline, see §80.47(i)(1)

(vii) For aromatics in diesel fuel, see §80.47(j)(1).

(2) The reference installation of the method-defined fuel parameter for the applicable 

designated test method must be shown to stay within the middle 50% of the distribution 

of an industry or commercially available monthly inter-laboratory crosscheck program 

for 3 out of 5 successive exchanges for at least a period of five months using good 

laboratory practices. Specifically, compute the difference between the instrument’s 

average measurement of the fuel closest to the applicable fuel standard (or to the average 

value for the fuel parameter in the complex model) and the mean for that fuel obtained by 

all of the non-outlier labs in the monthly inter-laboratory crosscheck program. 

Standardize this difference by expressing it in standard deviation units. These 

standardized inter-laboratory crosscheck differences should be placed in a moving 

average with a minimum span of five months. The instrument’s moving average in 

standard deviation units cannot be outside the central 50% of the distribution of all 

laboratories that participated in the inter-laboratory crosscheck program.

(3) The reference installation of the method-defined fuel parameter for the applicable 

designated test method must be shown to be in statistical quality control as specified in 

ASTM D6299 for a minimum period of five months using good laboratory practices. 

The system is still considered to be in statistical quality control and the five month time 

period will not re-start if–

(i) Regular maintenance and/or re-calibration conducted during the five months in 

SQC qualification time period is considered as part of in-control normal operation, 

and/or; 

(ii) If an assignable cause for ‘out of control’ is found, mitigated, and the system is 

brought back in statistical quality control during the five month time period that the 

reference installation is attempting to meet the five month in-statistical-control 

requirement, the five month time period does not re-start and the system is still 

considered to be ‘in-control’.

(4) For a voluntary consensus standards body, such as ASTM, or for a commercially 

available industry crosscheck program, the summary statistics (mean and standard 

error=standard deviation/square root [number of results]) from the VCSB or 

commercially available inter-laboratory cross-check program (ILCP) data may be used as 

is without imposing the reference installations requirements of this section, provided that 

the number of non-outlying results is greater than 16 for both the designated and 
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alternative test methods. The determination of ARV of check standards as specified in 

ASTM D6299, clause 6.2.2.1 and Note 7 shall be followed for the inter-laboratory

crosscheck program. The use of VCSB or commercially available ILCP data as 

described above is deemed suitable for an ASTM D6708 assessment of VCSB alternative 

test methods.

(l) Qualification criteria for Voluntary Consensus Standard Based (VCSB) MethodDefined Parameter Test Methods.

(1) Beginning January 1, 2016, include full test method documentation by the 

Voluntary Consensus Standard Based (VCSB) organization, including a description of 

the technology and/or instrumentation that makes the method functional.

(2) Include information reported in the test method that demonstrates the test method 

meets the applicable precision information for the method-defined fuel parameter as 

described in this section.

(3) Include information reported in the test method that demonstrates the test method 

has been evaluated using ASTM D6708 and whether the comparison is a “null” result or 

whether a correlation equation needs to be applied that predicts designated test method 

results from the applicable method-defined alternative test method.

(4) The test methods specified at §§80.2(w) and 80.46(a)(1), (a)(2), (b)(1), (c)(1), 

(d)(1), (e)(1), (f)(1), and (g)(1) and in use prior to [INSERT DATE 6 MONTHS 

PRIOR TO PUBLICATION IN THE FEDERAL REGISTER] are exempt from the 

requirements of paragraphs (l)(1) through (3) of this section.

(m) Qualification criteria for Non-Voluntary Consensus Standard Based (non-VCSB) 

Method-Defined Parameter Test Methods. For a non-VCSB method to be approved, the 

following information must be submitted to the Administrator by each test facility for 

each method that it wishes to have approved.

(1) Beginning January 1, 2016, full and thorough test method documentation, 

including a description of the technology and/or instrumentation that makes the method 

functional so a person lacking experience with the test instrument would be able to 

replicate its results.

(2) Information reported in the test method that demonstrates the test method meets 

the applicable precision information using good laboratory practices for the methoddefined fuel parameter as described in this section.

(3) Both the candidate method-defined Non-VCSB test method and its respective 

designated test method must be tested on a range of consensus named fuels or locallynamed reference materials that are typical of those analyzed by the facility in practice 

using good laboratory practices and must meet the data requirements for variability as 

required in ASTM D6708.

(4) The facility using the candidate method-defined non-VCSB test method must 

statistically establish through application of ASTM D6708 that the candidate method 

measures the same aspect of samples as applicable to its respective designated test 

method using good laboratory practices.
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(5) If the use of ASTM D6708 reveals that the candidate method-defined non-VCSB 

test method has sample-specific biases due to matrix effects that cannot be determined as 

random the method is disqualified. If however, it is determined that the candidate 

method-defined non-VCSB test method can be qualified on a narrow circumscribed range 

of fuels while still meeting the data requirements for variability as required in ASTM 

D6708 (see paragraph (m)(3) of this section), then the types of fuels on which the 

qualification was achieved and for which the method is to be approved must be specified 

in the candidate method-defined non-VCSB test method description. If there is any

restriction on the scope of fuels for which the candidate method-defined non-VCSB test 

method is to be qualified, the applicant must include a discussion of how the facility 

plans to screen sample for conformity to the scope. If the candidate method-defined test 

method is found to have minimal matrix effects, a statement to this effect must be 

included by the applicant in its application.

(6) The candidate method-defined non-VCSB test method precision qualification 

must be conducted in the form of “cross-method reproducibility” (Rcm) of the candidate 

method and applicable designated test method as required in ASTM D6708, where the 

Rcm must be equal to or less than 70 percent of the published reproducibility of the 

applicable designated test method using good laboratory practices.

(7) The applicant of the candidate method-defined non-VCSB test method must 

demonstrate through the use of ASTM D6708 whether a correlation to applicable 

designated test method is necessary. If it is determined through the use of this practice 

that the candidate method-defined non-VCSB test method requires a correlation equation 

in order to predict designated test method results, then this correlation equation must be 

applied to the candidate instruments output to obtain measurement results for regulatory 

purposes using good laboratory practices.

(8) Any additional information requested by the Administrator and necessary to 

render a decision as to approval of the test method.

(9) Samples used for precision and accuracy determination must be retained for 90 

days.

(10) Within 90 days of the receipt of materials required to be submitted under 

paragraphs (m)(1) through (9) of this section, the Administrator shall determine whether 

the test method is approved under this section.

(11) If the Administrator denies approval of the test method, within 90 days of receipt 

of all materials required to be submitted in paragraphs (m)(1) through (9) of this section, 

the Administrator will notify the applicant of the reasons for not approving the method. 

If the Administrator does not notify the applicant within 90 days of receipt of the 

application, then the test method shall be deemed approved.

(12) The Administrator may revoke approval of a test method under this section for 

cause, including, but not limited to, a determination by the Administrator that the 

approved test method has proved to be inadequate in practice.

(13) An independent third-party scientific review and written report and verification of 

the information provided pursuant to paragraphs (m)(1) through (9) of this section. The 

report and verification shall be based upon a site visit and review of relevant documents 

and shall separately identify each item required by paragraphs (m)(1) through (9) of this 
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section, describe how the independent third-party evaluated the accuracy of the 

information provided, state whether the independent third-party agrees with the 

information provided, and identify any exceptions between the independent third-party’s 

findings and the information provided.

(i) The information required under this section must be conducted by an independent 

third party who is a professional chemist and statistician, or who is a chemical engineer, 

with the following qualifications:

(A) For a refiner, importer, oxygenate producer, and oxygenate blender, the 

independent third party must have at least a bachelor’s degree in chemistry and statistics, 

or at least a bachelor’s degree in chemical engineering, from an accredited college in the 

United States, or the independent third party must be a subject matter expert with 

equivalent knowledge and qualification, with professional work experience in the 

petroleum or oxygenate field, especially with a demonstrated good working knowledge of 

ASTM D6708 and ASTM D6299.

(B) [Reserved]

(ii) To be considered an independent third-party under this paragraph (m)(13):

(A) The third-party shall not be employed by the refiner, importer, oxygenate 

producer, or oxygenate blender, or any subsidiary or employee of the refiner, import 

facility, oxygenate producing facility, or oxygenate blender.

(B) The third party shall be free from any interest in the refiner’s, importer’s, 

oxygenate producer’s, or oxygenate blender’s business.

(C) The refiner, importer, oxygenate producer, or oxygenate blender shall be free 

from any interest in the third-party’s business.

(D) Use of a third-party that is debarred, suspended, or proposed for debarment

pursuant to the Government-wide Debarment and Suspension regulations, 40 CFR part 

32, or the Debarment, Suspension and Ineligibility provisions of the Federal Acquisition 

Regulations, 48 CFR part 9 subpart 9.4, shall be deemed in noncompliance with the 

requirements of this section.

(iii) The independent third-party shall retain all records pertaining to the verification 

required under this section for a period of five years from the date of creation and shall 

deliver such records to the Administrator upon request.

(iv) The independent third party must provide EPA documentation of his or her 

qualifications as described in this paragraph (m) as part of the scientific review.

(14) If the Administrator finds that an individual test facility has provided false or 

inaccurate information under this section, upon notice from the Administrator the 

approval shall be void ab initio.

(n) Accuracy and Precision Statistical Quality Control (SQC) Requirements for the 

Absolute Fuel Parameters. Beginning January 1, 2016, a test shall not be considered a 

test using an approved test method unless the following quality control procedures are 

performed separately for each instrument used to make measurements:

(1) Every facility shall conduct tests on every instrument with a commercially

available gravimetric reference material, or check standard as defined in the ASTM 
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D6299 at least three times a year using good laboratory practices.. The facility must pretreat and assess results from the check standard testing after at least 15 testing occasions 

as described in section 8.2 of this standard practice. The facility must construct “MR” 

and “I” charts with control lines as described in section 8.4 and appropriate Annex 

sections of this standard practice. In circumstances where the absolute difference 

between the mean of multiple back-to-back tests of the standard reference material and 

the accepted reference value of the standard reference material is greater than 0.75 times 

the published reproducibility of the test method must be investigated by the facility. 

Records of the standard reference materials measurements as well as any investigations 

into any exceedance of these criteria must be kept for a period of five years.

(2)(i) Precision SQC. Every facility shall conduct tests on every instrument with a 

quality control material as defined in paragraph 3.2.3 in ASTM D6299 either once per 

week or once per every 20 productions tests, whichever is more frequent. The facility

must construct and maintain an “I” chart as described in section 7 and section A1.5.1 and 

a “MR” chart as described in section A1.5.2. Any violations of control limit(s) should be 

investigated by personnel of the facility and records kept for a period of five years.

(ii) Validation of New QC Material. When a test facility is making a transition from 

one batch of QC material to the next batch of QC material, the facility will either 

construct an “I” chart as described in section 7 and section A1.5.1 of ASTM D6299, or 

follow the “Q-Procedure” in Annex 1.9 of ASTM D6299. In following the Q-Procedure 

if the plot of results from the “old” and “new” QC materials on its respective chart shows 

no special-cause signals, then the result of the “new” QC material will be considered 

valid.

(iii) For test facilities opting to use the Q-procedure, the first run on the new QC batch 

should be validated by either an overlap in-control result of the old batch, or by a single 

execution of an accompanying standard reference material. The new QC material result 

would be considered validated if the single result of the standard reference material is 

within the established site precision (R’) of the Accepted Reference Value of the standard 

reference material, as determined by ASTM D6792. 

(iv) The expanded uncertainty of the accepted reference value of consensus named 

fuels shall have the following accuracy qualification criterion: Accuracy qualification 

criterion = square root [(0.75R)^2+(0.75R)^2/L], where L = the number of single results 

obtained from different labs used to calculate the consensus ARV. 

(v) These records must be kept by the facility for a period of five years.

(o) Accuracy and Precision Statistical Quality Control (SQC) Requirements for the 

Voluntary Consensus Standard Based (VCSB) Method-Defined Fuel Parameters. 

Beginning January 1, 2016, a test shall not be considered a test using an approved test 

method unless the following quality control procedures are performed separately for each 

instrument used to make measurements:

(1) Accuracy SQC. Every facility shall conduct tests of every instrument with a 

commercially available check standard as defined in the ASTM D6299 at least three 

times a year using good laboratory practices.. The check standard must be an ordinary

fuel with levels of the fuel parameter of interest close to either the applicable regulatory
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standard or the average level of use for the facility. The Accepted Reference Value of the 

check standard must be determined by the respective designated test method for the fuel 

parameter following the guidelines of ASTM D6299. The facility must pre-treat and 

assess results from the check standard testing after at least 15 testing occasions as 

described in section 8.2 of this standard practice. The facility must construct “MR” and 

“I” charts with control lines as described in section 8.4 and appropriate Annex sections of 

this standard practice. In circumstances where the absolute difference between the mean 

of multiple back-to-back tests of the standard reference material and the accepted 

reference value of the standard reference material is greater than 0.75 times the published 

reproducibility of the test method must be investigated by the facility. Records of the 

standard reference materials measurements as well as any investigations into any 

exceedance of these criteria must be kept for a period of five years.

(2)(i) Precision SQC. Every facility shall conduct tests of every instrument with a 

quality control material as defined in paragraph 3.2.3 in ASTM D6299 either once per 

week or once per every 20 productions tests, whichever is more frequent. The facility

must construct and maintain an “I” chart as described in section 7 and section A1.5.1 and 

a “MR” chart as described in section A1.5.2. Any violations of control limit(s) should be 

investigated by personnel of the facility and records kept for a period of five years.

(ii) Validation of New QC Material. When a test facility is making a transition from 

one batch of QC material to the next batch of QC material, the facility will either 

construct an “I” chart as described in section 7 and section A1.5.1 of ASTM D6299, or 

follow the “Q-Procedure” in Annex 1.9 of ASTM D6299. In following the Q-Procedure 

if the plot of results from the “old” and “new” QC materials on its respective chart shows 

no special-cause signals, then the result of the “new” QC material will be considered 

valid.

(iii) For test facilities opting to use the Q-procedure, the first run on the new QC batch 

should be validated by either an overlap in-control result of the old batch, or by a single 

execution of an accompanying standard reference material. The new QC material result 

would be considered validated if the single result of the standard reference material is 

within the established site precision (R’) of the Accepted Reference Value of the standard 

reference material, as determined by ASTM D6792. 

(iv) The expanded uncertainty of the accepted reference value of consensus named 

fuels shall have the following accuracy qualification criterion: Accuracy qualification 

criterion = square root [(0.75R)^2+(0.75R)^2/L], where L = the number of single results 

obtained from different labs used to calculate the consensus ARV. 

(v) These records must be kept by the facility for a period of five years.

(p) Accuracy and Precision Statistical Quality Control (SQC) Requirements for the 

Non-Voluntary Consensus Standard Based (Non-VCSB) Method-Defined Fuel 

Parameters. Beginning January 1, 2016, a test shall not be considered a test using an 

approved test method unless the following quality control procedures are performed 

separately for each instrument used to make measurements:

(1) Accuracy SQC for Non-VCSB Method-Defined test methods with minimal 

matrix effects. Every facility shall conduct tests on every instrument with a 
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commercially available check standard as defined in the ASTM D6299 at least three 

times a year using good laboratory practices.. The check standard must be an ordinary

fuel with levels of the fuel parameter of interest close to either the applicable regulatory

standard or the average level of use for the facility. The Accepted Reference Value of the 

check standard must be determined by the respective designated test method for the fuel 

parameter following the guidelines of ASTM D6299. The facility must pre-treat and 

assess results from the check standard testing after at least 15 testing occasions as 

described in section 8.2 of this standard practice. The facility must construct “MR” and 

“I” charts with control lines as described in section 8.4 and appropriate Annex sections of 

this standard practice. In circumstances where the absolute difference between the mean 

of multiple back-to-back tests of the standard reference material and the accepted 

reference value of the standard reference material is greater than 0.75 times the published 

reproducibility of the test method must be investigated by the facility. Records of the 

standard reference materials measurements as well as any investigations into any 

exceedance of these criteria must be kept for a period of five years.

(2)(i) Accuracy SQC for Non-VCSB Method-Defined test methods with high sensitivity

to matrix effects. Every facility shall conduct tests on every instrument with a production 

fuel on at least a quarterly basis using good laboratory practices. The production fuel 

must be representative of the production fuels that are routinely analyzed by the facility. 

The Accepted Reference Value of the production fuel must be determined by the 

respective reference installation of the designated test method for the fuel parameter 

following the guidelines of ASTM D6299. The facility must pre-treat and assess results 

from the check standard testing after at least 15 testing occasions as described in section 

8.2 of this standard practice. The facility must construct “MR” and “I” charts with 

control lines as described in section 8.4 and appropriate Annex sections of this standard 

practice. In circumstances where the absolute difference between the mean of multiple 

back-to-back tests of the standard reference material and the accepted reference value of 

the standard reference material is greater than 0.75 times the published reproducibility of 

the test method must be investigated by the facility. Documentation on the identity of the 

reference installation and its control status must be maintained on the premises of the 

method-defined alternative test method. Records of the standard reference materials 

measurements as well as any investigations into any exceedances of this criterion must be 

kept for a period of five years.

(ii) Each facility is required to send every 20th production batch of gasoline or diesel 

fuel to EPA’s laboratory, along with the facility’s measurement result used to certify the 

batch using the respective method-defined non-VCSB test method. The EPA retains the 

right to return such sample on a blind basis for a required reanalysis on the respective 

method-defined non-VCSB test method within 180 days upon receipt of such sample. 

(3)(i) Precision SQC. Every facility shall conduct tests on every instrument with a 

quality control material as defined in paragraph 3.2.3 in ASTM D6299 either once per 

week or once per every 20 productions tests, whichever is more frequent. The facility

must construct and maintain an “I” chart as described in section 7 and section A1.5.1 and 

a “MR” chart as described in section A1.5.2. Any violations of control limit(s) should be 

investigated by personnel of the facility and records kept for a period of five years.
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(ii) Validation of New QC Material. When a test facility is making a transition from 

one batch of QC material to the next batch of QC material, the facility will either 

construct an “I” chart as described in section 7 and section A1.5.1 of ASTM D6299, or 

follow the “Q-Procedure” in Annex 1.9 of ASTM D6299. In following the Q-Procedure 

if the plot of results from the “old” and “new” QC materials on its respective chart shows 

no special-cause signals, then the result of the “new” QC material will be considered 

valid.

(iii) For test facilities opting to use the Q-procedure, the first run on the new QC batch 

should be validated by either an overlap in-control result of the old batch, or by a single 

execution of an accompanying standard reference material. The new QC material result 

would be considered validated if the single result of the standard reference material is 

within the established site precision (R’) of the Accepted Reference Value of the standard 

reference material, as determined by ASTM D6792. 

(iv) The expanded uncertainty of the accepted reference value of consensus named 

fuels shall have the following accuracy qualification criterion: Accuracy qualification 

criterion = square root [(0.75R)^2+(0.75R)^2/L], where L = the number of single results 

obtained from different labs used to calculate the consensus ARV. 

(v) These records must be kept by the facility for a period of five years.

(q) Record retention requirements for the test methods approved under this subpart. 

Each individual test facility must retain records related to the establishment of accuracy

and precision values, all test method documentation, and any statistical quality control 

testing and analysis under this section using good laboratory practices for a period for 

five years.

(r) Materials incorporated by reference. The published materials identified in this 

section are incorporated by reference into this section with the approval of the Director of 

the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. To enforce any edition 

other than that specified in this section, a document must be published in the Federal 

Register and the material must be available to the public. All approved materials are 

available for inspection at the Air and Radiation Docket and Information Center (Air 

Docket) in the EPA Docket Center (EPA/ DC) at Rm. 3334, EPA West Bldg., 1301

Constitution Ave. NW., Washington, DC. The EPA/DC Public Reading Room hours of 

operation are 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. 

The telephone number of the EPA/DC Public Reading Room is (202) 566–1744, and the 

telephone number for the Air Docket is (202) 566–1742. These approved materials are 

also available for inspection at the National Archives and Records Administration 

(NARA). For information on the availability of this material at NARA, call (202) 741–

6030 or go to http:// www.archives.gov/federal_register/ code_of_federal_regulations/ 

ibr_locations.html. In addition, these materials are available from the sources listed 

below.

(1) ASTM International material. The following standards are available from ASTM 

International, 100 Barr Harbor Dr., P.O. Box C700, West Conshohocken, PA 19428-

2959, (877) 909–ASTM, or http://www.astm.org:
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(i) ASTM D86-12, Standard Test Method for Distillation of Petroleum Products at 

Atmospheric Pressure, approved December 1, 2012.

(ii) ASTM D1319-13, Standard Test Method for Hydrocarbon Types in Liquid 

Petroleum Products by Fluorescent Indicator Adsorption, approved May 1, 2013.

(iii) ASTM D3606-10, Standard Test Method for Determination of Benzene and 

Toluene in Finished Motor and Aviation Gasoline by Gas Chromatography, approved 

October 1, 2010.

(iv) ASTM D5191-13, Standard Test Method for Vapor Pressure of Petroleum 

Products (Mini Method), approved December 1, 2013.

(v) ASTM D5599-00 (Reapproved 2010), Standard Test Method for Determination of 

Oxygenates in Gasoline by Gas Chromatography and Oxygen Selective Flame Ionization 

Detection, approved October 1, 2010.

(vi) ASTM D6299-13, Standard Practice for Applying Statistical Quality Assurance 

and Control Charting Techniques to Evaluate Analytical Measurement System 

Performance, approved October 1, 2013.

(vii) ASTM D6667-10, Standard Test Method for Determination of Total Volatile 

Sulfur in Gaseous Hydrocarbons and Liquefied Petroleum Gases by Ultraviolet 

Fluorescence, approved October 1, 2010.

(viii) ASTM D6708-13, Standard Practice for Statistical Assessment and Improvement 

of Expected Agreement Between Two Test Methods that Purport to Measure the Same 

Property of a Material, approved May 1, 2013.

(ix) ASTM D6792-13, Standard Practice for Quality System in Petroleum Products 

and Lubricants Testing Laboratories, approved May 15, 2013.

(x) ASTM D7039-13, Standard Test Method for Sulfur in Gasoline, Diesel Fuel, Jet 

Fuel, Kerosine, Biodiesel, Biodiesel Blends, and Gasoline-Ethanol Blends by

Monochromatic Wavelength Dispersive X-ray Fluorescence Spectrometry, approved 

September 15, 2013, approved September 15, 2013.

(2) [Reserved]

6. Section 80.65 is amended by:

a. Revising paragraph (d)(1).

b. Removing and reserving paragraph (d)(2)(iv).

c. Revising paragraph (d)(2)(v).

d. Revising paragraph (d)(3).

e. Revising paragraphs (e)(1) introductory text, (e)(1)(i), and (e)(2) introductory

text.

f. Adding paragraphs (e)(3) and (e)(4).

g. Revising paragraphs (f)(1)(i) and (f)(3)(iii)(A).

h. Adding a new paragraph (f)(5).

i. Revising paragraph (i) introductory text.

j. Revising paragraphs (i)(1)(ii) and (i)(1)(iii).

k. Revising paragraphs (i)(4)(ii) introductory text and (i)(4)(ii)(A).

l. Revising paragraph (i)(6)(i).
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§ 80.65 General requirements for refiners and importers.

* * * * *

(d) * * *

(1) All gasoline produced or imported shall be properly designated as reformulated 

gasoline, conventional gasoline, RBOB, or CBOB.

(2) * * *

(iv) [Reserved]

(v) For each of the following parameters, either gasoline or RBOB which meets the 

standard applicable to that parameter on a per-gallon basis or on average–

(A) Toxics emissions performance;

(B) NOX emissions performance in the case of gasoline certified using the complex 

model.

(C) Benzene content; and 

(D) In the case of VOC-controlled gasoline or RBOB certified using the complex 

model, VOC emissions performance; and

* * * * *

(3) Every batch of reformulated gasoline, conventional gasoline, RBOB, or CBOB 

produced or imported at each refinery or import facility shall be assigned a number (the 

“batch number”), consisting of the EPA-assigned refiner or importer registration number, 

the EPA facility registration number, the last two digits of the year in which the batch 

was produced, and a unique number for the batch, beginning with the number one for the 

first batch produced or imported each calendar year and each subsequent batch during the 

calendar year being assigned the next sequential number (e.g., 4321–54321–95–000001, 

4321–54321–95–000002, etc.).

(e) * * *

(1) Except as provided in paragraphs (e)(3) and (4) of this section, each refiner or 

importer shall, for each batch of reformulated gasoline or RBOB produced or imported, 

determine the volume and the value of each of the properties specified in paragraph 

(e)(2)(i) of this section, except that the value for RVP must be determined only in the 

case of reformulated gasoline or RBOB that is VOC-controlled. These determinations 

shall–

(i) Be based on a representative sample of the reformulated gasoline or RBOB that is 

analyzed using the methodologies specified in § 80.46 through December 31, 2015, or, 

beginning January 1, 2016, in either § 80.46 or § 80.47;

* * * * *

(2) In the event that the value of any of these properties is determined by the refiner 

or importer and by an independent laboratory in conformance with the requirements of 

paragraph (f) of this section–

* * * * *

(3) Beginning January 1, 2013, API Gravity is not required to be measured or 

reported for the purpose of batch certification.
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(4) For the purposes of meeting the requirements of this paragraph (e) for any winter 

fuel parameter except benzene, oxygenate, RVP and sulfur, any refiner or importer may, 

prior to analysis, combine samples of gasoline collected from more than one batch of 

gasoline or blendstock (“composite sample”), and treat such composite sample as one 

batch of gasoline or blendstock provided that the refiner or importer meets all the 

following requirements:

(i) Samples must be from a single reporting year, must be limited to non-VOC 

gasoline, and must be of a single grade of gasoline or of a single type of batch-produced 

blendstock.

(ii) Combines samples of gasoline that are produced or imported over a period no 

longer than one month. Blendstock samples of a single blendstock type obtained from 

continuous processes over a calendar month may be mixed together to form one 

blendstock sample and the sample subsequently analyzed for the required fuel 

parameters.

(iii)(A)Samples shall have been collected and stored using good laboratory practices in 

order to prevent change in product composition with regard to baseline properties and to 

minimize loss of volatile fractions of the sample.

(B) Properties of the retained samples shall be adjusted for loss of butane or pentane 

by comparing the RVP measured immediately after blending with the RVP determined at 

the time that the supplemental properties are measured.

(C) The volume of each batch or shipment sampled, to the nearest gallon, shall have 

been noted and the sum of the volumes, in gallons, calculated.

(iv) For each batch or shipment sampled, the ratio of its volume to the total volume 

determined in paragraph (e)(4)(iii)(C) of this section shall be determined to three decimal 

places. This shall be the volumetric fraction of the shipment in the mixture.

(v) The total minimum volume required to perform duplicate analyses to obtain 

values of all of the required fuel parameters shall be determined.

(vi) The volumetric fraction determined in paragraph (e)(4)(iv) of this section for each 

batch or shipment shall be multiplied by the value determined in paragraph (e)(4)(v) of 

this section.

(vii) The resulting value determined in paragraph (e)(4)(vi) of this section for each 

batch or shipment shall be the volume of each batch or shipment’s sample to be added to 

the mixture. This volume shall be determined to the nearest milliliter.

(viii) The appropriate volumes of each shipment’s sample shall be thoroughly mixed 

and the solution analyzed per the methods required under § 80.46 or § 80.47, as 

applicable.

(ix) Uses the total of the volumes of the batches of gasoline that comprise the 

composite sample, and the results of the analyses of the composite sample, for purposes 

of compliance calculations under this paragraph (e).

(f) * * *

(1) * * *

(i) Option 1. The refiner or importer shall, for each batch of reformulated gasoline or 

RBOB that is produced or imported, have the value for each property specified in 
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paragraph (e)(2)(i) of this section determined by an independent laboratory that collects 

and analyzes a representative sample from the batch using the methodologies specified in 

§ 80.46 through December 31, 2015, and the methodologies specified in § 80.47 

beginning January 1, 2016.

* * * * *

(3) * * *

(iii) * * *

(A) For each compliance year beginning with the 2014 compliance year, a single 

annual report for calendar year January through December may be submitted by the 

following March 31.

* * * * *

(5) A refiner or importer may designate one alternate independent laboratory to 

perform testing required for compliance if all the following conditions are met: 

(i) The alternate independent laboratory meets all provisions of this section for 

designated independent laboratories.

(ii) The alternate laboratory is used only when the designated independent laboratory

per paragraph (f)(2) of this section is unavailable and cannot perform testing required for 

compliance, for example, when the primary designated laboratory is closed, the apparatus 

for certain test methods are down, or independent laboratory personnel are not available.

(iii) The alternate independent laboratory is not used to select a preferred test result. 

* * * * *

(i) Exclusion of previously certified gasoline. Any refiner who uses previously

certified reformulated gasoline, conventional gasoline, RBOB, or CBOB to produce 

reformulated gasoline or RBOB must exclude the previously certified gasoline for 

purposes of demonstrating compliance with the standards under § 80.41. This exclusion 

must be accomplished by the refiner as follows:

(1) * * *

(ii) In the case of previously certified reformulated gasoline or RBOB determine the 

emissions performances for toxics and NOX, except as provided in § 80.41(e) and (f), 

and VOC for VOC-controlled gasoline, and the designations for VOC control.

(iii) In the case of previously certified conventional gasoline or CBOB, determine the 

exhaust toxics and NOX emissions performances, except as provided in § 80.101(c)(3) 

and (4).

* * * * *

(4) * * *

(ii) Where a refiner uses previously certified conventional gasoline or CBOB to 

produce reformulated gasoline or RBOB–

(A) The refiner must include the volume and properties of any batch of previously

certified conventional gasoline or CBOB as a negative batch in the refiner’s anti-dumping 

compliance calculations under § 80.101(g) for the refinery, or where applicable, the 

refiner’s aggregation under § 80.101(h); and

* * * * *
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(6)(i) Any refiner may use the procedures specified in this paragraph (i) to combine 

previously certified conventional gasoline or CBOB with reformulated gasoline or 

RBOB, to reclassify conventional gasoline or CBOB into reformulated gasoline or 

RBOB, or to change the designations of reformulated gasoline or RBOB with regard to 

VOC control.

* * * * *

7. Section 80.66 is amended by revising paragraph (f) to read as follows:

§ 80.66 Calculation of reformulated gasoline properties.

* * * * *

(f) Per-gallon RVP shall be determined based upon the measurement of RVP of a 

representative sample of a batch of gasoline. The total RVP value associated with a batch 

of gasoline (in RVP-gallons) is calculated by multiplying the RVP times the volume.

* * * * *

8. Section 80.74 is amended by:

a. Revising the introductory text.

b. Revising paragraphs (a) introductory text and (a)(1).

c. Adding paragraphs (a)(3) and (a)(4).

d. Revising paragraph (b)(8).

§ 80.74 Recordkeeping requirements.

All parties in the gasoline distribution network and the distribution network for pentane 

for use by pentane blenders under § 80.86, shall maintain records containing the 

information as required in this section. These records shall be retained for a period of 

five years from the date of creation, and shall be delivered to the Administrator of EPA or 

to the Administrator’s authorized representative upon request.

(a) All regulated parties. Any refiner, gasoline importer, oxygenate blender, producer 

of pentane for use by pentane blenders, importer of pentane for use by pentane blenders, 

carrier, distributor, reseller, retailer, or wholesale-purchaser-consumer who sells, offers 

for sale, dispenses, supplies, offers for supply, stores, blends, transports, or causes the 

transportation of any reformulated gasoline, RBOB, or pentane for use by pentane 

blenders shall maintain records containing the following information:

(1) The product transfer documentation for all reformulated gasoline, RBOB, or 

pentane for use by pentane blenders for which the party is the transferor or transferee; 

and
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* * * * *

(3) For producers and importers of pentane for use by pentane blenders, in addition to 

the records specified in paragraph (a)(1) of this section, records demonstrating that each 

batch of such pentane is compliant with the standards in § 80.86.

(4) For pentane blenders, in addition to the records specified in paragraph (a)(1) of 

this section, records demonstrating compliance quality assurance program requirements 

in § 80.85.

(b) * * *

(8) In the case of butane or pentane blended into reformulated gasoline or RBOB 

under § 80.82 or § 80.85, documentation of all the following:

(i) The volume of butane added.

(ii) The volume of the pentane added.

(iii) The volume of reformulated gasoline or RBOB both prior to and subsequent to 

the butane or pentane blending.

(iv) The purity and properties of the butane specified in § 80.82(c) and (d), as 

appropriate.

(v) The purity and properties of the pentane specified in § 80.85(c) and (d), as 

appropriate.

(vi) Compliance with the requirements of §§ 80.82 and 80.85; and

* * * * *

9. Section 80.75 is amended by:

a. Revising the introductory text.

b. Revising paragraph (a).

c. Removing and reserving paragraph (b).

d. Revising paragraph (c)(1) introductory text.

e. Revising paragraph (d).

f. Revising paragraphs (e) introductory text and (e)(1).

g. Revising paragraph (g) introductory text.

h. Revising paragraph (h) introductory text.

i. Revising paragraph (i).

j. Removing and reserving paragraph (k).

k. Revising paragraph (l).

l. Revising paragraph (m).

m. Revising paragraph (o).

n. Adding paragraph (p).

§ 80.75 Reporting requirements.
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Any refiner, gasoline importer, producer of pentane for use by a pentane blender, and 

importer of pentane for use by a pentane blender shall report as specified in this section, 

and shall report such other information as the Administrator may require.

(a) Quarterly reports for reformulated gasoline. Any refiner or importer that produces 

or imports any reformulated gasoline or RBOB shall submit quarterly reports to the 

Administrator for each refinery at which such reformulated gasoline or RBOB was 

produced and for all such reformulated gasoline or RBOB imported by each importer.

(1) The quarterly reports shall be for all such reformulated gasoline or RBOB 

produced or imported during the following time periods:

(i) The first quarterly report shall include information for reformulated gasoline or 

RBOB produced or imported from January 1 through March 31, and shall be submitted 

by June 1 of each year.

(ii) The second quarterly report shall include information for reformulated gasoline or 

RBOB produced or imported from April 1 through June 30, and shall be submitted by

September 1 of each year.

(iii) The third quarterly report shall include information for reformulated gasoline or 

RBOB produced or imported from July 1 through September 30, and shall be submitted 

by December 1 of each year.

(iv) The fourth quarterly report shall include information for reformulated gasoline or 

RBOB produced or imported from October 1 through December 31, and shall be 

submitted by March 31 of each year.

(2) All the following information shall be included in each quarterly report for each 

batch of reformulated gasoline or RBOB which is included under paragraph (a)(1) of this 

section:

(i) The batch number.

(ii) The date of production.

(iii) The volume of the batch.

(iv) The grade of gasoline produced (i.e., premium, mid-grade, or regular).

(v) For any refiner or importer, all the following:

(A) Each designation of the gasoline, pursuant to § 80.65.

(B) The properties, along with identification of the test method used to measure those 

properties, pursuant to §§ 80.65(e) and 80.66.

(vi) For any importer, the PADD in which the import facility is located.

(vii) [Reserved]

(viii) In the case of any previously certified gasoline used in a refinery operation under 

the terms of § 80.65(i), all the following information relative to the previously certified 

gasoline when received at the refinery:

(A) Identification of the previously certified gasoline as such.

(B) The batch number assigned by the receiving refinery.

(C) The date of receipt.

(D) The volume, properties (along with identification of the test method used to 

measure those properties), and designation of the batch.
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(ix) In the case of butane blended with reformulated gasoline or RBOB under § 80.82, 

all the following:

(A) Identification of the butane batch as complying with the provisions of § 80.82.

(B) Identification of the butane batch as commercial or non-commercial grade butane.

(C) The batch number of the butane.

(D) The date of production of the gasoline produced using the butane batch.

(E) The volume of the butane batch.

(F) The properties of the butane batch specified by the butane supplier, or the 

properties specified in § 80.82(c) or (d), as appropriate, along with the identification of 

the test method used to measure those properties.

(G) The volume of the gasoline batch subsequent to the butane blending.

(x) In the case of any imported GTAB, identification of the gasoline as GTAB.

(xi) In the case of pentane blended with reformulated gasoline or RBOB under § 

80.85, all the following:

(A) Identification of the pentane batch as complying with the provisions of § 80.85.

(B) Identification of the pentane batch as commercial or non-commercial grade 

pentane.

(C) The batch number of the pentane.

(D) The company and facility identification numbers of the supplier of the pentane 

batch.

(E) The date of production of the gasoline produced using the pentane batch.

(F) The volume of the pentane batch.

(G) The properties of the pentane batch specified by the pentane supplier, or the 

properties specified in § 80.82(c) or (d), as appropriate along with the test method used to 

measure these properties.

(H) The volume of the gasoline batch subsequent to the pentane blending.

(3) Information pertaining to gasoline produced or imported during 1994 shall be 

included in the first quarterly report in 1995.

(b) [Reserved]

(c) * * *

(1) Any refiner or importer that produced or imported any reformulated gasoline or 

RBOB under the complex model that was to meet the VOC emissions performance 

standards on average (“averaged reformulated gasoline”) shall submit to the 

Administrator, with the third quarterly report, a report for each refinery or importer for 

such averaged reformulated gasoline produced or imported during the previous VOC 

averaging period. Beginning January 1, 2014, the information required by this paragraph 

(c) shall be submitted with the fourth quarter report pursuant to § 80.75(a)(1)(iv). This 

information shall be reported separately for the following categories:

* * * * *

(d) Benzene content averaging reports. Pursuant to § 80.41(f)(3), for any refiner, 

refinery or importer not subject to the applicable standards at § 80.41(f)(1), the report 
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required by this paragraph (d) is not required beginning January 1, 2014, or beginning 

January 1, 2016 for all other refiners.

(1) Any refiner or importer that produced or imported any reformulated gasoline or 

RBOB that was to meet the benzene content standards on average (“averaged 

reformulated gasoline”) shall submit to the Administrator, with the fourth quarterly 

report, a report for each refinery or importer for such averaged reformulated gasoline that 

was produced or imported during the previous toxics averaging period.

(2) All the following information shall be reported:

(i) The volume of averaged reformulated gasoline or RBOB in gallons.

(ii) The compliance total content of benzene.

(iii) The actual total content of benzene, along with identification of the test methods 

used to measure the content of benzene.

(iv) The number of benzene credits generated as a result of actual total benzene being 

less than compliance total benzene.

(v) The number of benzene credits required as a result of actual total benzene being 

greater than compliance total benzene.

(vi) The number of benzene credits transferred to another refinery or importer.

(vii) The number of benzene credits obtained from another refinery or importer.

(e) Toxics emissions performance averaging reports. Pursuant to § 80.41(f)(3), for 

any refiner, refinery or importer not subject to the applicable standards at § 80.41(f)(1), 

the report required by this paragraph (e) is not required beginning January 1, 2014, or 

beginning January 1, 2016 for all other refiners.

(1) Any refiner or importer that produced or imported any reformulated gasoline or 

RBOB that was to meet the toxics emissions performance standards on average 

(“averaged reformulated gasoline”) shall submit to the Administrator, with the fourth 

quarterly report, a report for each refinery or importer for such averaged reformulated 

gasoline that was produced or imported during the previous toxics averaging period.

* * * * *

(g) NOX emissions performance averaging reports. Pursuant to § 80.41(f)(2), for any 

refiner, refinery or importer not subject to the applicable standards at § 80.41(f)(1), the 

report required by this paragraph (g) is not required beginning January 1, 2014.

* * * * *

(h) Credit transfer reports. As an additional part of the fourth quarterly report 

required by this section, any refiner or importer shall, for each refinery or importer, 

supply the following information for any benzene credits that are transferred from or to 

another refinery or importer:

* * * * *

(i) Covered areas of gasoline use report. Any refiner that produced any reformulated 

gasoline that was to meet any reformulated gasoline standard on average (“averaged 

reformulated gasoline”) shall, for each refinery at which such averaged reformulated 
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gasoline was produced, submit to the Administrator, with the fourth quarterly report, a 

report that contains the identity of each covered area that was supplied with any averaged 

reformulated gasoline produced at each refinery during the previous year.

* * * * *

(k) [Reserved]

(l) Reports for per-gallon compliance gasoline. In the case of reformulated gasoline 

or RBOB for which compliance with each of the standards set forth in § 80.41 is 

achieved on a per-gallon basis, the refiner or importer shall submit to the Administrator, 

by March 31 of each year, a report of the volume of each designated reformulated 

gasoline or RBOB produced or imported during the previous calendar year for which 

compliance is achieved on a per-gallon basis, and a statement that each gallon of this 

reformulated gasoline or RBOB met the applicable standards.

(m) Reports of compliance audits. Any refiner or importer shall submit the report of 

the compliance audit required by § 80.65(h) to the Administrator by June 1 of each year.

* * * * *

(o) Additional reporting requirements for refiners that blend butane or pentane with 

reformulated gasoline or RBOB. For refiners that blend any butane or pentane with 

reformulated gasoline or RBOB under § 80.82 or § 80.85, the refiner shall submit to the 

Administrator, by March 31 of each year, a report for the refinery which includes all the 

following information for the previous calendar year:

(1) The total volume of butane and the total volume of pentane blended with 

reformulated gasoline or RBOB at the refinery, separately for reformulated gasoline and

RBOB.

(2) The total volume of reformulated gasoline or RBOB produced using butane and 

the total volume of reformulated gasoline or RBOB produced using pentane, separately 

for reformulated gasoline and RBOB.

(3) A statement that each gallon of reformulated gasoline or RBOB produced using 

butane or pentane met the applicable per-gallon standards under § 80.41.

(4) A statement that all butane and pentane blended with reformulated gasoline or 

RBOB at the refinery is included in the volume reported in paragraph (o)(2) of this 

section.

(p) Reporting requirements for producers and importers of pentane for use by pentane 

blenders. Any producer of pentane for use by pentane blenders, or importer of pentane 

for use by a pentane blender that produces or imports any pentane for use by a pentane 

blender pursuant to the requirements of § 80.86 shall submit annual reports to the 

Administrator for each facility at which pentane for use by pentane blenders was 

produced and for all such pentane imported by each importer.
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(1) All the following information shall be included in each annual report for each 

batch of pentane for use by pentane blenders which is produced or imported from January

1 to December 31 of each year:

(i) The batch number.

(ii) The date of production.

(iii) The volume of the batch.

(iv) Whether the batch was produced to the standards for blender-commercial grade 

pentane pursuant to § 80.86(a)(3) or blender non-commercial grade pentane pursuant to § 

80.86(a)(4).

(v) The properties, pursuant to the testing requirements of § 80.86(a)(3) or (a)(4) as 

applicable.

(vi) A statement that the batch of pentane is composed solely of carbon, hydrogen, 

oxygen, nitrogen, and sulfur. 

(vii) For any importer, the PADD in which the import facility is located.

(2) Each annual report shall include the total volume of blender commercial grade 

pentane pursuant to § 80.86(a)(3) or blender-non-commercial grade pentane pursuant to § 

80.86(a)(4) for the reporting period.

(3) Annual reports shall be submitted by March 31 of each year.

10. Section 80.77 is amended by revising the introductory text and paragraphs (c), 

(d), and (f) to read as follows:

§ 80.77 Product transfer documentation.

On each occasion when any person transfers custody or title to any reformulated gasoline, 

RBOB, or pentane for use by a pentane blender other than when gasoline is sold or 

dispensed for use in motor vehicles at a retail outlet or wholesale purchaser-consumer 

facility, the transferor shall provide to the transferee documents which include the 

following information:

* * * * *

(c) The volume of gasoline, RBOB, or pentane for use by a pentane blender which is 

being transferred; 

(d) The location of the gasoline or pentane for use by a pentane blender at the time of 

the transfer;

* * * * *

(f) The proper identification of the product as reformulated gasoline, RBOB, or 

pentane for use by a pentane blender; and

* * * * *
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11. Section 80.80 is amended by revising paragraphs (b) and (d) to read as follows:

§ 80.80 Penalties.

* * * * *

(b) Any violation of a standard for average compliance during any averaging period, 

or for per-gallon compliance for any batch of gasoline or blender grade pentane, shall 

constitute a separate violation for each and every standard that is violated.

* * * * *

(d)(1) Any violation of any per-gallon standard or of any per-gallon minimum or pergallon maximum, other than the standards specified in paragraph (e) of this section, shall 

constitute a separate day of violation for each and every day such gasoline or blender 

grade pentane giving rise to such violations remains any place in the gasoline or blender 

grade pentane distribution system, beginning on the day that the gasoline or blender grade 

pentane that violates such per-gallon standard is produced or imported and distributed 

and/or offered for sale, and ending on the last day that any such gasoline or blender grade 

pentane is offered for sale or is dispensed to any ultimate consumer for use in any motor 

vehicle; unless the violation is corrected by altering the properties and characteristics of 

the gasoline or blender grade pentane giving rise to the violations and any mixture of 

gasolines or blender grade pentane that contains any of the gasoline or blender grade 

pentane giving rise to the violations such that said gasoline or mixture of gasolines or 

said blender grade pentane or mixture of blender grade pentanes has the properties and 

characteristics that would have existed if the gasoline or blender grade pentane giving 

rise to the violations had been produced or imported in compliance with all per-gallon 

standards.

(2) For the purposes of this paragraph (d), the length of time the gasoline or blender 

grade pentane in question remained in the gasoline or blender grade pentane distribution 

system shall be deemed to be twenty-five days; unless the respective party or EPA 

demonstrates by reasonably specific showings, by direct or circumstantial evidence, that 

the gasoline or blender grade pentane giving rise to the violations remained any place in 

the gasoline or blender grade pentane distribution system for fewer than or more than 

twenty-five days.

* * * * *

12. Section 80.82 is amended to read as follows:

§ 80.82 Butane blending. 
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A refiner for any refinery that produces gasoline by blending butane with previously 

certified gasoline (PCG) may meet the sampling and testing requirements for this part as 

follows:

(a) Except as provided in paragraphs (e) and (i) of this section, any refinery that 

blends butane for which the refinery has documents from the butane supplier which 

demonstrate that the butane is commercial grade, as defined in paragraph (c) of this 

section, may demonstrate compliance with the standards in this part based on the 

properties specified in paragraph (c) of this section, or the properties specified by the 

butane supplier.

(b)(1) Except as provided in paragraphs (e) and (i) of this section, any refiner that blends 

butane for which the refiner has documents from the butane supplier which demonstrate 

that the butane is non-commercial grade, as defined in paragraph (d) of this section, may

demonstrate compliance with the standards in this part based on the properties specified 

in paragraph (d) of this section, or the properties specified by the butane supplier, 

provided that the refinery–

(i) Conducts a quality assurance program of sampling and testing the butane obtained 

from each separate butane supplier which demonstrates that the butane has the properties 

specified in paragraph (d) of this section; and

(ii) The frequency of sampling and testing for the butane received from each butane 

supplier must be one sample for every 500,000 gallons of butane received, or one sample 

every three months, whichever is more frequent.

(2) Where test results indicate the butane does not meet the requirements in paragraph

(b)(1) of this section, the refiner may–

(i) Blend the butane with conventional gasoline, or reformulated gasoline that has 

been downgraded to conventional gasoline, provided the equivalent emissions 

performance of the butane batch, as determined using the provisions in § 80.101(g)(3), 

meets the refinery’s standards under § 80.101 and the refiner meets all of the standards 

and requirements applicable to refiners of conventional gasoline under this part;

(ii) Blend the butane with reformulated gasoline or RBOB, provided that the final 

batch of butane blended with reformulated gasoline or RBOB meets the applicable pergallon standards in § 80.41(e), as determined using the test methods in § 80.46 or § 

80.47, as applicable.

(c) Commercial grade butane is defined as butane for which test results demonstrate 

that the butane is 95% pure and has all the following properties:

(1) Olefins ≤1.0 vol%.

(2) Aromatics ≤2.0 vol%.

(3) Benzene ≤0.03 vol%.

(4) Sulfur ≤30 ppm from January 1, 2005 through December 31, 2016; ≤10 ppm 

beginning January 1, 2017 and thereafter.
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(d) Non-commercial grade butane is defined as butane for which test results 

demonstrate the butane has all the following properties:

(1) Olefins ≤10.0 vol%.

(2) Aromatics ≤2.0 vol%.

(3) Benzene ≤0.03 vol%.

(4) Sulfur ≤30 ppm beginning January 1, 2005 through December 31, 2016; ≤10 

ppm beginning January 1, 2017 and thereafter.

(e)(1) When butane is blended with conventional gasoline under this section during the 

period May 1 through September 15, the refiner shall demonstrate through sampling and 

testing, using the test method for Reid vapor pressure in § 80.46 or § 80.47, as applicable, 

that each batch of conventional gasoline blended with butane meets the volatility

standards specified in § 80.27.

(2) Butane may not be blended with any reformulated gasoline or RBOB during the 

period April 1 through September 30, or with any reformulated gasoline or RBOB 

designated as VOC-controlled, under this section.

(f) When butane is blended with previously certified gasoline under this section, 

product transfer documents which accompany the gasoline blended with butane must 

comply with all of the requirements of § 80.77 or § 80.106, as appropriate.

(g) Butane blended with previously certified gasoline during a period of up to one 

month may be included in a single batch for purposes of reporting to EPA, however, 

commercial grade butane and non-commercial grade butane must be reported as separate 

batches.

(h) Where a refiner chooses to include butane blended with gasoline in the refinery’s 

annual average compliance calculations–

(1) In the case of butane blended with conventional gasoline, the equivalent 

emissions performance of the butane must be calculated in accordance with the 

provisions of § 80.101(g)(3). For purposes of this paragraph (h)(1), the property values in 

§ 80.82(c) or (d), as appropriate, may be used;

(2) In the case of butane blended with reformulated gasoline or RBOB, compliance 

with the reformulated gasoline standards may not be demonstrated using the provisions of 

this section;

(3) All butane blended into gasoline during the annual averaging period must be 

included in annual average compliance calculations for the refinery.

(i) A refiner who only blends commercial grade or non-commercial grade butane 

into PCG may meet the sampling and testing requirements of this part by meeting the 

requirements of paragraphs (a) through (f) and (h)(3) of this section and all the following 

additional requirements:
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(1) The per-gallon sulfur content of every batch of butane must not exceed 30 ppm 

from January 1, 2005 through December 31, 2016, and 10 ppm beginning January 1, 

2017 and thereafter.

(2) The refiner obtains test results from the butane supplier that demonstrate that the 

sulfur content of each load does not exceed the applicable per-gallon sulfur standard 

under paragraph (i)(1) of this section through test results of samples of butane contained 

in the storage tank from which the butane blender is supplied.

(i) Sampling and testing for the sulfur content of the butane by the supplier must be 

subsequent to each receipt of butane into the supplier’s storage tank or the sampling and 

testing must be immediately before transfer of butane to the butane blender.

(ii) The testing must be performed in accord with the provisions of § 80.46, § 80.47, 

or other test methods as approved by the Administrator as applicable.

(iii) The butane blender must obtain a copy of the butane supplier’s test results at the 

time of each transfer of butane to the butane blender.

(3) The sulfur content and volume of each batch of gasoline produced is that of the 

butane that the refiner blends into PCG for the purposes of calculating compliance with 

the applicable per-gallon sulfur standard.

(4) The requirements of paragraphs (i)(1) through (3) of this section apply regardless 

of whether the butane is commercial grade or non-commercial grade.

(5) The quality assurance testing requirement of paragraph (b)(1) of this section 

applies regardless of whether the butane is commercial grade or non-commercial grade.

(6) If any of the requirements of this paragraph (i) are not met, in whole or in part for 

any butane blended into gasoline, that butane is deemed in violation of the gasoline 

standards in § 80.1603(a).

(j) The PCG procedures of § 80.1640 may be used to meet the sampling and testing 

requirements of subpart O of this part.

13. A new § 80.85 is added to subpart D to read as follows:

§ 80.85 Pentane blending. 

A refiner for any refinery where gasoline is produced by adding blender-commercial

grade pentane or blender-non-commercial grade pentane meeting the requirements of § 

80.86 to previously certified gasoline (PCG) may meet the sampling and testing 

requirements for this part as follows:

(a) Any refinery that blends pentane for which the refinery has product transfer 

documents from a registered pentane supplier which demonstrate that the pentane is 

blender-commercial grade, as defined in § 80.86(a)(3), may demonstrate compliance with 

the standards in this part based on the properties specified in § 80.86(a)(3), or the 

properties specified by the pentane supplier, provided that the refinery does all the 

following:
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(1) Obtains a copy of the pentane supplier’s test results at the time of each transfer of 

pentane to the pentane blender that indicates that the blender-commercial grade pentane 

complies with the requirements of § 80.86(a)(3).

(2) Conducts a quality assurance program of sampling and testing the pentane 

obtained from each separate pentane supplier using test procedures that have been 

approved by the Administrator which demonstrates that the pentane has the properties 

specified in § 80.86(a)(3). Samples and tests the pentane received from each pentane 

supplier at a frequency of one sample for every 350,000 gallons of pentane received, or 

one sample every three months, whichever is more frequent.

(3) Enters into a contract with all parties who transport or store blender-commercial 

grade pentane for use by the refiner to assure that an adequate quality assurance program 

is implemented to ensure that blender-commercial grade pentane will not be 

contaminated in transit to the refinery. 

(b) Any refiner that blends pentane for which the refiner has product transfer 

documents from a registered pentane supplier which demonstrate that the pentane is 

blender-non-commercial grade, as defined in § 80.86(a)(4), may demonstrate compliance 

with the standards in this part based on the properties specified in § 80.86(a)(4), or the 

properties specified by the pentane supplier, provided that the refinery does all the 

following:

(1) Obtains a copy of the pentane supplier’s test results at the time of each transfer of 

pentane to the pentane blender that indicates that the blender-non-commercial grade 

pentane complies with the requirements of § 80.86(a)(4).

(2) Conducts a quality assurance program of sampling and testing the pentane 

obtained from each separate pentane supplier using test procedures that have been 

approved by the Administrator which demonstrates that the pentane has the properties 

specified in § 80.86(a)(4). Samples and tests the pentane received from each pentane 

supplier at a frequency of one sample for every 250,000 gallons of pentane received, or 

one sample every three months, whichever is more frequent.

(3) Enters into a contract with all parties who transport or store blender-noncommercial grade pentane for use by the refiner to assure that an adequate quality

assurance program is implemented to ensure that blender-non-commercial grade pentane 

will not be contaminated in transit to the refinery. 

(c) When pentane is blended with conventional gasoline under this section during the 

period May 1 through September 15, the refiner shall demonstrate through sampling and 

testing, using the test method for Reid vapor pressure in § 80.46 or § 80.47 as applicable, 

that each batch of conventional gasoline blended with pentane meets the volatility

standards specified in § 80.27, and in any EPA approved SIP.

(d) When pentane is blended with conventional gasoline, CBOB, reformulated 

gasoline, or RBOB under this section, product transfer documents which accompany the 

gasoline blended with pentane must comply with all of the requirements of § 80.77 or § 

80.106, as appropriate.
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(e) Pentane blended with conventional gasoline, CBOB, reformulated gasoline, or 

RBOB during a period of up to one month may be included in a single batch for purposes 

of reporting to EPA, if the refiner meets the sample compositing requirements in § 

80.91(d)(4)(iii), and reports blender-commercial grade and blender-non-commercial 

grade pentane as separate batches.

(f) The provisions of this section may not be used for any pentane blended with any

reformulated gasoline or RBOB during the period April 1 through September 30, or with 

any reformulated gasoline or RBOB designated as VOC-controlled.

(g) All pentane blended into gasoline during the annual averaging period must be 

included in annual average compliance calculations for the refinery.

(h) If any of the requirements of this section are not met, in whole or in part for any 

pentane blended into gasoline, that pentane is deemed in violation of the gasoline 

standards in § 80.1603(a).

(i) If a refiner does not fully implement the requirements of this section, they may

not rely on test results from the pentane producer, and may only blend pentane with 

gasoline if they fully comply with all applicable requirements of this part 80, including 

the sampling and testing requirements applicable to refiners who produce gasoline by

adding blendstocks to PCG. 

14. A new § 80.86 is added to subpart D to read as follows:

§ 80.86 Requirements for producers and importers of pentane used by pentane 

blenders. 

Producers and importers of pentane may designate batches of pentane as blendercommercial grade pentane or blender-non-commercial grade pentane suitable for use by

pentane blenders pursuant to the requirements in this section. 

(a) Standards. (1) The pentane must be composed solely of carbon, hydrogen, 

oxygen, nitrogen, and sulfur.

(2) The pentane must meet the standards for blender-commercial grade pentane or 

blender-non-commercial grade pentane.

(3) For blender commercial grade pentane, the producer or importer must conduct 

analytical testing to on each production batch to demonstrate compliance with the 

following standards using sampling and testing procedures that have been approved by

the Administrator:

(i) Pentane ≥ 95 vol%.
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(ii) Olefins ≤1.0 vol%.

(iii) Aromatics ≤2.0 vol%.

(iv) Benzene ≤0.03 vol%.

(v) C6 and higher carbon number hydrocarbons ≤5.0 vol%.

(vi) Sulfur ≤30 ppm from January 1, 2005 through December 31, 2016; ≤10 ppm 

beginning January 1, 2017 and thereafter.

(4) For blender-non-commercial grade pentane, the producer or importer must 

conduct analytical testing on each production batch to demonstrate compliance with the 

following standards using sampling and testing procedures that have been approved by 

the Administrator:

(i) Olefins ≤10.0 vol%.

(ii) Aromatics ≤2.0 vol%.

(iii) Benzene ≤0.03 vol%.

(iv) C6 and higher carbon number hydrocarbons ≤5.0 vol%.

(v) Sulfur ≤30 ppm beginning January 1, 2005 through December 31, 2016; ≤10 

ppm beginning January 1, 2017 and thereafter.

(b) Registration. The producer or importer of pentane for use by pentane blenders 

must register with EPA pursuant to the following requirements:

(1) Registration dates. Any producer or importer of pentane for use by pentane 

blenders must register with EPA at least thirty days in advance of the first date that such 

person will produce or import pentane for use by pentane blenders.

(2) Registration for producers of pentane for use by pentane blenders. Registration 

shall be on forms and following procedures prescribed by the Administrator, and shall 

include all the following information:

(i) The name, business address, contact name, e-mail address, and telephone number 

of the producer of pentane for use by pentane blenders.

(ii) For each separate facility that will produce pentane for use by pentane blenders, 

the facility name, physical location, contact name, telephone number, and type of facility.

(iii) For each separate facility that will produce pentane for use by pentane blenders–

(A) Whether records are kept on-site or off-site of the refinery.

(B) If records are kept off-site, the primary off-site storage facility name, physical 

location, contact name, and telephone number.

(iv) A description of the production facility which demonstrates that the facility is 

capable of producing pentane that is complaint with the requirements of this section 

without significant modifications to the existing facility. 

(v) A description of the means pentane will be shipped from the production facility to 

the pentane blender(s) and the associated quality assurance practices which demonstrate 

that contamination during distribution can be adequately controlled so as not to cause the 

pentane to be in violation of the standards in this section.

(vi) A description of the sampling and testing procedures that will be used pursuant to 

the requirements of paragraphs (a)(3) and (4) of this section. 

(vii) EPA will supply a company registration number to each producer of pentane for 

use by pentane blenders, and a facility registration number for each production facility
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that is identified. These registration numbers shall be used in all reports to the 

Administrator.

(viii) Any producer of pentane for use by pentane blenders shall submit updated 

registration information to the Administrator within thirty days of any occasion when the 

registration information previously supplied becomes incomplete or inaccurate.

(3) Registration for importers of pentane for use by pentane blenders. Registration 

shall be on forms and following procedures prescribed by the Administrator, and shall 

include all the following information:

(i) The name, business address, contact name, and e-mail address, telephone number 

of the importer.

(ii) For each importer’s operations in a single PADD–

(A) Whether records are kept on-site at the registered address or off-site.

(B) If records are kept off-site, the primary off-site storage facility name, physical 

location, contact name, e-mail address, and telephone number.

(iii) A description of the importer’s operating facility which demonstrates that the 

importer is capable of providing pentane that is complaint with the requirements of this 

section without significant modifications to the existing facility. 

(iv) A description of the means pentane will be shipped from the importer’s facility to 

the pentane blender(s) and the associated quality assurance practices which demonstrate 

that contamination during distribution can be adequately controlled so as not to cause the 

pentane to be in violation of the standards in this section.

(v) A description of the sampling and testing procedures that will be used pursuant to 

the requirements of paragraphs (a)(3) and (4) of this section. 

(vi) EPA will supply a company registration number to each importer. This 

registration number shall be used in all reports to the Administrator.

(vii) Any importer of pentane for use by pentane blenders shall submit updated 

registration information to the Administrator within thirty days of any occasion when the 

registration information previously supplied becomes incomplete or inaccurate.

(c) PTDs. The producer or importer of pentane for use by pentane blenders must 

initiate a PTD for each batch that it ships from its facility which contains the statement in 

paragraph (c)(1) or (c)(2) of this section, as applicable. 

(1) “Blender commercial grade pentane for use by pentane blenders”.

(2) “Blender non-commercial grade pentane for use by pentane blenders”.

(3) PTDs that are compliant with the requirements in paragraph (c) of this section 

must be transferred from each party transferring pentane for use by pentane blenders to 

each party that receives pentane for use by pentane blenders through to the pentane 

blender. 

(4) Alternative PTD language to that specified in paragraphs (c)(1) and (c)(2) of this 

section may be used as approved by EPA.

(d) Batch numbers. Every batch of pentane for use by pentane blenders that is 

produced or imported at a pentane production or import facility shall be assigned a 
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number (the “batch number”), consisting of the EPA-assigned registration number, the 

EPA facility registration number, the last two digits of the year in which the batch was 

produced, and a unique number for the batch, beginning with the number one for the first 

batch produced or imported each calendar year and each subsequent batch during the 

calendar year being assigned the next sequential number (e.g., 4321–54321–95–000001, 

4321–54321–95–000002, etc.).

15. A new § 80.87 is added to subpart D to read as follows:

§ 80.87 Controls and prohibitions for producers, importers, and distributors of 

pentane for use by pentane blenders. 

(a) Prohibited acts. No person shall–

(1) Produce, import, sell, distribute, offer for sale or distribution, blend, supply, offer 

for supply, store, transport, or cause the transportation of any product designated as 

pentane for use by pentane blenders unless–

(i) Each gallon of such pentane for use by pentane blenders meets the applicable 

standards specified in § 80.86; and

(ii) The product transfer documentation for such pentane for use by pentane blenders 

complies with the requirements in §§ 80.77 and 80.86(c).

(2) Produce or import pentane for use by pentane blenders unless the producer or 

importer complies with the recordkeeping requirements of § 80.74, the reporting 

requirements of § 80.75, and the requirements of § 80.86.

(3) Fail to meet any other requirements of § 80.86.

(4) Cause another person to commit an act in violation of this paragraph (a). 

(b) Persons liable. The following persons are liable for violations of prohibited acts 

in paragraph (a) of this section:

(1) Any person who manufactures, imports, sells, distributes, offers for sale or 

distribution, blends, supplies, offers for supply, stores, transports, or causes the 

transportation of any product designated as pentane for use by pentane blenders that 

violates § 80.86 is liable for the violation.

(2) Any person that causes another party to violate paragraph (a) of this section is 

liable for a violation of this paragraph (b).

(3) Any parent corporation is liable for any violations of this section that are 

committed by any of its wholly-owned subsidiaries.

(4) Each partner to a joint venture, or each owner of a facility owned by two or more 

owners, is jointly and severally liable for any violation of this subpart that occurs at the 

joint venture facility or a facility that is owned by the joint owners, or a facility that is 

committed by the joint venture operation or any of the joint owners of the facility.

(c) Any person who violates this section is liable for the violation.
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(d) Determination of compliance. EPA may establish noncompliance with standards 

using any information, including the results of testing using methods that are not included 

in § 80.46.

(e) Dates controls and prohibitions begin. The controls and prohibitions specified in 

paragraph (a) of this section apply at any location on or after [INSERT DATE 60 DAYS 

AFTER PUBLICATION IN THE FEDERAL REGISTER].

(f) Penalties. (1) Any person liable for a violation under this section is subject to 

civil penalties as specified in sections 205 and 211(d) of the Clean Air Act (42 U.S.C. 

7524 and 7545(d)) for every day of each such violation and the amount of economic 

benefit or savings resulting from each violation.

(2) Any person liable under this section for a violation of an applicable standards or 

causing another person to violate the requirements is subject to a separate day of violation 

for each and every day the non-complying pentane or gasoline remains any place in the 

pentane or gasoline distribution system. 

(3) For purposes of paragraph (c) of this section, the length of time the pentane or 

gasoline in question remained in the pentane or gasoline distribution system is deemed to 

be twenty-five days, unless a person subject to liability or EPA demonstrates by

reasonably specific showings, by direct or circumstantial evidence, that the noncomplying pentane or gasoline remained in the distribution system for fewer than or more 

than twenty-five days. 

(g) Any person liable under this section for failure to meet, or causing a failure to 

meet, a provision of this subpart is liable for a separate day of violation for each and 

every day such provision remains unfulfilled.

Subpart E—[Amended] 

16. Section 80.101 is amended by: 

a. Revising paragraph (i)(1)(i)(A).

b. Revising paragraph (i)(3)(i)(C).

c. Revising paragraph (i)(3)(ii)(C).

§ 80.101 Standards applicable to refiners and importers.

* * * * *

(i) * * *

(1) * * *

(i)(A) Through December 31, 2015, determine the value of each of the properties 

required for determining compliance with the standards that are applicable to the refiner 

or importer, by collecting and analyzing a representative sample of gasoline or 

blendstock from the batch, using methodologies specified in § 80.46; beginning January
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1, 2016, determine the value of each of the properties required for determining 

compliance with the standards that are applicable to the refiner or importer, by collecting 

and analyzing a representative sample of gasoline or blendstock from the batch, using 

methodologies specified in § 80.47; except that–

* * * * *

(3) * * *

(i) * * *

(C) The testing must be for each applicable parameter specified under § 

80.65(e)(2)(i), using the test methods specified under § 80.46 through December 31, 

2015, or under § 80.47 beginning January 1, 2016.

* * * * *

(ii) * * *

(C) The testing must be for each applicable parameter specified under § 

80.65(e)(2)(i), using the test methods specified under § 80.46 through December 31, 

2015, or under § 80.47 beginning January 1, 2016.

* * * * *

17. Section 80.105 is amended by:

a. Revising paragraph (a)(5).

b. Revising paragraph (a)(7).

c. Revising paragraph (c).

d. Revising paragraph (d)(2).

§ 80.105 Reporting requirements.

(a) * * *

(5) All the following information for each batch of conventional gasoline or batch of 

blendstock included under paragraph (a) of this section:

(i) The batch number.

(ii) The date of production.

(iii) The volume of the batch.

(iv) The grade of gasoline produced (i.e., premium, mid-grade, or regular).

(v) The properties, along with identification of the test method used to measure those 

properties, pursuant to § 80.101(i).

(vi) In the case of any previously certified gasoline used in a refinery operation under 

the terms of § 80.101(g)(9), all the following information relative to the previously

certified gasoline when received at the refinery:

(A) Identification of the previously certified gasoline as such.

(B) The batch number assigned by the receiving refinery.

(C) The date of receipt.

(D) The volume, properties (along with identification of the test method used to 

measure those properties), and designation of the batch.
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(vii) In the case of butane blended with conventional gasoline under § 80.82, all the 

following:

(A) Identification of the butane batch as complying with the provisions of § 80.82.

(B) Identification of the butane batch as commercial or non-commercial grade butane.

(C) The batch number of the butane.

(D) The date of production of the gasoline produced using the butane.

(E) The volume of the butane batch.

(F) The properties of the butane batch specified by the butane supplier, along with 

identification of the test method used to measure those properties, or the properties 

specified in § 80.82(c) or (d), as appropriate.

(G) Where butane is blended with conventional gasoline during the period May 1 

through September 15, the Reid vapor pressure, along with identification of the test 

method used to measure Reid vapor pressure (per § 80.46 through December 31, 2015 

and § 80.47 beginning January 1, 2016);

(viii) In the case of pentane blended with conventional gasoline under § 80.85, all the 

following:

(A) Identification of the pentane batch as complying with the provisions of §§ 80.85 

and 80.86.

(B) Identification of the pentane batch as blender-commercial grade or blender-noncommercial grade pentane.

(C) The batch number of the pentane.

(D) The date of production of the gasoline produced using the pentane.

(E) The volume of the pentane batch.

(F) The properties of the pentane batch specified by the pentane supplier, or the 

properties specified in § 80.85(c) or (d), as appropriate.

(G) Where pentane is blended with conventional gasoline during the period May 1 

through September 15, the Reid vapor pressure, as measured using the appropriate test 

method in § 80.46 or § 80.47, as applicable.

(ix) In the case of any imported GTAB, identification of the gasoline as GTAB.

* * * * *

(7) For refiners that blend any butane with conventional gasoline under § 80.82, or 

any pentane with conventional gasoline under the report required under § 80.85, the 

report described in paragraph (a) of this section must include all the following 

information for the annual averaging period:

(i) The total volume of butane blended with conventional gasoline.

(ii) The total volume of conventional gasoline produced using butane.

(iii) A statement that the gasoline produced using butane meets all applicable 

downstream standards that apply to conventional gasoline under this subpart E, along 

with the test methods used to determine compliance with the downstream standards that 

apply to conventional gasoline under this subpart E.

(iv) A statement that all butane blended with conventional gasoline at the refinery is 

included in the volume under paragraph (a)(7)(i) of this section, or a statement that all 

butane blended with conventional gasoline is included in the refinery’s annual average 

compliance calculations under § 80.101.
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(v) The total volume of pentane blended with conventional gasoline.

(vi) The total volume of conventional gasoline produced using pentane.

(vii) A statement that the gasoline produced using pentane meets all applicable 

downstream standards that apply to conventional gasoline under this subpart E.

(viii) A statement that all pentane blended with conventional gasoline at the refinery is 

included in the volume under paragraph (a)(7)(v) of this section, or a statement that all 

pentane blended with conventional gasoline is included in the refinery’s annual average 

compliance calculations under § 80.101.

* * * * * 

(c) For each averaging period, each refiner for each refinery and importer shall 

submit to the Administrator of EPA, by June 1 of each year, a report in accordance with 

the requirements for the Attest Engagements of § 80.125 through § 80.131.

(d) * * *

(2) Submitted to EPA by March 31 each year for the prior calendar year averaging 

period; and

* * * * * 

Subpart G--[Amended] 

19. Section 80.161 is amended by:

a. Revising paragraph (b)(1)(ii)(A)(2) and adding paragraph (b)(1)(ii)(A)(3).

b. Revising paragraph (b)(2) introductory text.

c. Revising paragraphs (b)(3)(ii)(C), (b)(3)(v), and (b)(3)(viii).

d. Revising paragraph (d)(1).

§ 80.161 Detergent additive certification program.

* * * * *

(b) * * *

(1) * * *

(ii) * * *

(A) * * *

(2) In the case of the alternative national generic certification option pursuant to § 

80.163(a)(1)(iii), the minimum recommended concentration must equal or exceed the 

amount mixed into the associated test fuel specified in § 80.177, which was shown to 

satisfy the fuel injector deposit control and intake valve deposit control performance tests 

and standards specified in § 80.176.

(3) In the case of any other detergent certification option, the minimum recommended 

concentration must equal or exceed the amount mixed into the associated test fuel 
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specified in § 80.164, which was shown to satisfy the fuel injector deposit control and 

intake valve deposit control performance tests and standards specified in § 80.165.

* * * * *

(2) The detergent additive manufacturer (or other certifying party) must submit to 

EPA a sample of the actual detergent additive package which was used in the certification 

test fuels specified in § 80.164 or § 80.177 or, if such sample is not available, then a 

sample which has the same composition as the package used in certification testing.

* * * * *

(3) * * *

(ii) * * *

(C) Complete documentation of the test fuel formulation, IVD demonstration 

procedures, fuel injector deposit demonstration procedure if applicable, detergent 

performance test procedures, and test results are available for EPA's inspection upon 

request. 

* * * * *

(v) In the case of a national or PADD certification (pursuant to § 80.163(a)(1) or (b)) 

for which the test fuel was specially formulated from refinery blend stocks, the results of 

the IVD demonstration test, pursuant to § 80.164(b)(3). In the case of an alternative 

national generic certification (pursuant to § 80.163(a)(1)(iii)), the results of the IVD 

demonstration test and fuel injector deposit demonstration test (pursuant to § 80.177).

* * * * *

(viii) The test concentration(s) of the subject detergent additive in each test fuel, and the 

corresponding test results (percent flow restriction demonstrated in the fuel injector test 

and milligrams of deposit per valve demonstrated in the IVD test).

* * * * *

(d) * * *

(1) If a detergent blender possesses deposit control performance test results as 

specified in § 80.165, § 80.166, or § 80.176 which show that the minimum treat rate 

recommended by the manufacturer of a detergent additive product exceeds the amount of 

that detergent actually required for effective deposit control, then, upon informing EPA in 

writing of these circumstances, the detergent blender may use the detergent at the lower 

concentration substantiated by these test results.

* * * * *

20. Section 80.163 is amended by adding a new paragraph (a)(1)(iii) to read as 

follows:

§ 80.163 Detergent certification options.

* * * * *

(a) * * *

(1) * * *
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(iii) Alternative national generic certification option. To be certified under this option, 

a candidate detergent must meet the deposit control performance test requirements and 

standards specified in § 80.176 using test fuels that conform to the requirements in § 

80.177. A detergent certified under this option is eligible to be used at a conforming 

LAC in any grade of gasoline, with or without an oxygenate component.

* * * * *

21. Section 80.164 is amended by revising paragraph (a) introductory text to read as 

follows:

§ 80.164 Certification test fuels.

(a) General requirements. This section provides specifications for the test fuels 

required in conjunction with the certification options described in §§ 80.163(a)(1) and 

80.163(b) through (d). For each such certification option, the associated test fuel must 

meet or exceed the levels of four basic fuel parameters (aromatics, fuel sulfur, olefins, 

and T–90) prescribed here and may also contain specified oxygenate compounds. In 

addition, pursuant to paragraph (b)(3) of this section, some fuels must undergo an IVD 

demonstration test before they are eligible to be used as test fuels under this certification 

program. Test fuel characteristics must be reported to EPA in the detergent certification 

letter required pursuant to § 80.161(b)(3). The specifications for the test fuels required in 

conjunction with the alternative national generic certification option in § 80.163(a)(1)(iii) 

are contained in § 80.177.

* * * * *

22. Section 80.165 is revised to read as follows:

§ 80.165 Certification test procedures and standards.

This section specifies the deposit control test requirements and performance standards 

which must be met in order to certify detergent additives for use in unleaded gasoline, 

pursuant to § 80.161(b)(1)(ii)(A)(3). These standards must be met in the context of the 

specific test procedures identified in paragraphs (a) and (b) of this section, except as 

provided in paragraph (c) of this section. The testing must be conducted and the 

performance standards met when the subject detergent additive is mixed in a test fuel 

meeting all relevant requirements of § 80.164, including the deposit-forming tendency

demonstration specified in § 80.164(b)(3), if applicable. Complete test documentation 

must be submitted by the certifying party within 30 days of receipt of a written request 

from EPA for such records. The certification test procedures and standards associated 

with the alternative national generic certification option in § 80.163(a)(1)(iii) are 

contained in § 80.176.
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(a) Fuel injector deposit control testing. The required test fuel must produce no more 

than 5% flow restriction in any one injector when tested in accordance with ASTM 

D5598. At the option of the certifier, fuel injector flow may be measured at intervals 

during the 10,000 mile test cycle described in ASTM D5598, in addition to the flow 

measurements required at the completion of the test cycle, but not more than every 1,000 

miles.

(b) Intake valve deposit control testing. The required test fuel must produce the 

accumulation of less than 100 mg of intake valve deposits on average when tested in 

accordance with ASTM D5500. 

(c) Materials incorporated by reference. The published materials identified in this 

section are incorporated by reference into this section with the approval of the Director of 

the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. To enforce any edition 

other than that specified in this section, a document must be published in the Federal 

Register and the material must be available to the public. All approved materials are 

available for inspection at the Air and Radiation Docket and Information Center (Air 

Docket) in the EPA Docket Center (EPA/ DC) at Rm. 3334, EPA West Bldg., 1301

Constitution Ave. NW., Washington, DC. The EPA/DC Public Reading Room hours of 

operation are 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. 

The telephone number of the EPA/DC Public Reading Room is (202) 566–1744, and the 

telephone number for the Air Docket is (202) 566–1742. These approved materials are 

also available for inspection at the National Archives and Records Administration 

(NARA). For information on the availability of this material at NARA, call (202) 741–

6030 or go to http:// www.archives.gov/federal_register/ code_of_federal_regulations/ 

ibr_locations.html. In addition, these materials are available from the sources listed 

below.

(1) ASTM International material. The following standards are available from ASTM 

International, 100 Barr Harbor Dr., P.O. Box C700, West Conshohocken, PA 19428-

2959, (877) 909–ASTM, or http://www.astm.org:

(i) ASTM D5500-98 (Reapproved 2008), Standard Test Method for Vehicle 

Evaluation of Unleaded Automotive Spark-Ignition Engine Fuel for Intake Valve Deposit 

Formation, approved July 1, 2008.

(ii) ASTM D5598-01 (Reapproved 2012), Standard Test Method for Evaluating 

Unleaded Automotive Spark-Ignition Engine Fuel for Electronic Port Fuel Injector 

Fouling, approved November 1, 2012.

(2) [Reserved]

23. Section 80.167 is amended by revising paragraph (a) to read as follows:

§ 80.167 Confirmatory testing.

* * * * *
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(a) Confirmatory testing conducted to evaluate the validity of detergent certifications 

under the national, PADD, or fuel-specific options under §§ 80.163(a)(1) and 80.163(b) 

through (d) will generally entail a single vehicle test using the procedures detailed in § 

80.165. The test fuel(s) used in conducting such confirmatory certification testing will 

contain the specified fuel parameters at or below the minimum levels specified in § 

80.164, and will otherwise conform to the applicable certification test fuel specifications 

therein. Confirmatory testing conducted to evaluate the validity of detergent 

certifications under the alternative national generic certification option in § 

80.163(a)(1)(iii) will generally entail a single test using the procedures detailed in § 

80.177. The test fuel(s) used in conducting such confirmatory certification testing will 

contain the specified fuel parameters at or below the minimum levels specified in § 

80.177, and will otherwise conform to the applicable certification test fuel specifications 

therein. 

* * * * *

24. A new § 80.175 is added to subpart G and reserved as follows:

§ 80.175 [Reserved]

25. A new § 80.176 is added to subpart G to read as follows:

§ 80.176 Alternative certification test procedures and standards.

This section specifies the deposit control test requirements and performance standards 

which must be met in order to certify detergent additives for use in unleaded gasoline 

pursuant to § 80.161(b)(1)(ii)(A)(2). These standards must be met in the context of the 

specific test procedures identified in paragraphs (a) and (b) of this section. Testing must 

be conducted and the performance standards met when the subject detergent additive is 

mixed in a test fuels meeting all relevant requirements of § 80.177. Complete test 

documentation must be submitted by the certifying party within 30 days of receipt of a 

written request from EPA for such records.

(a) Fuel injector deposit control testing. The required test fuel must produce no more 

than one inoperative injector when tested in accordance with the fuel injector deposit test 

procedure specified in paragraph (c) of this section.

(b) Intake valve deposit control testing. The required test fuel must produce the 

accumulation of less than 50 mg of intake valve deposits on average when tested in 

accordance with ASTM D6201. ASTM D6201-04 (Reapproved 2009), “Standard Test 

Method for Dynamometer Evaluation of Unleaded Spark-Ignition Engine Fuel for Intake 

Valve Deposit Formation,” approved June 1, 2009, is incorporated by reference into this 

section with the approval of the Director of the Federal Register under 5 U.S.C. 552(a) 
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and 1 CFR part 51. To enforce any edition other than that specified in this section, a 

document must be published in the Federal Register and the material must be available 

to the public. Copies are available from ASTM International, 100 Barr Harbor Dr., P.O. 

Box C700, West Conshohocken, PA 19428-2959, (877) 909–ASTM, 

http://www.astm.org. The document is also available for inspection at the Air and 

Radiation Docket and Information Center (Air Docket) in the EPA Docket Center (EPA/ 

DC) at Rm. 3334, EPA West Bldg., 1301 Constitution Ave. NW., Washington, DC. The 

EPA/DC Public Reading Room hours of operation are 8:30 a.m. to 4:30 p.m., Monday

through Friday, excluding legal holidays. The telephone number of the EPA/DC Public 

Reading Room is (202) 566–1744, and the telephone number for the Air Docket is (202) 

566–1742. The document is also available for inspection at the National Archives and 

Records Administration (NARA). For information on the availability of this material at 

NARA, call 202-741-6030 or go to: 

http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

(1) Tests conducted for the intake valve deposit demonstration test pursuant to §

80.177(b)(4) and to demonstrate compliance with the intake valve deposit control 

standards in this section must be conducted using the same engine block and cylinder 

head.

(2) All results must be derived from operationally valid tests in accordance with the 

test validation criteria of ASTM D6201.

(3) Test results shall be reported for individual intake valves and as an average of all 

intake valves.

(c) Fuel injector deposit test procedure. (1) Summary of Test Procedure. After 

flushing the vehicle fuel system with the fuel to be tested and installing new injectors, an 

automatic starter control system starts the vehicle and lets it idle for five minutes. The 

engine is then shut off and allowed to soak for 25 minutes. This cycle is repeated for a 

total of 192 cycles (96 hours). During this time, the engine is kept at operating 

temperature with block heaters. After the 96 hours of start/soak cycles, the engine is 

allowed to hot-soak for 48 hours, during which time the engine is not started but is 

maintained at operating temperature. At the end of the 48-hour hot soak, the block 

heaters are turned off and the engine is allowed to cool naturally to room temperature. At 

the end of this 48-hour ambient temperature soak, an injector balance test is conducted to 

determine whether any poppet nozzles are stuck closed.

(2) Facilities and Equipment – (i) Location. A temperature-controlled garage or large 

room is needed. A dynamometer is not needed, since this test is an idle test. The room 

temperature shall be maintained in the range of 68-75°F. The room shall be equipped 

with an exhaust system that connects to the vehicle tail pipe to remove the exhaust gases 

from the building. It is recommended that an interlock be provided so that if the building 

exhaust system fails, the vehicle test will shut down.

(ii) Electrical Power. Two 110-volt, 15-amp circuits are needed (20-amp circuits are 

recommended) to operate the four block heaters and a battery charger.

(iii) Fuel Drain Facility. A facility is required to drain the fuel from the vehicle 

between tests. The fuel is drained from the service port on the fuel rail, near the back of 
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the engine. A commercial cart equipped with a tank and a suction pump is recommended 

for this operation.

(iv) Vehicle. A Chevrolet Astro or GMC Safari van, model year 1998-2001, shall be 

used for the test. Either two-wheel drive or all-wheel drive is satisfactory, although the 

former allows easier installation of the block heaters.

(v) Injectors. New injectors, General Motors part number 17091432, shall be used 

for each test.

(vi) Block Heaters. Four block heaters, General Motors part number 12371293, are 

needed for each vehicle. Two heaters shall be installed on each side of the engine, in the 

freeze plug locations.

(vii) Battery Charger. Because of the large number of starts and the very short engine 

running time, a battery charger is needed. It is recommended that the charger be installed 

permanently on the vehicle and remain plugged in while the test is in progress.

(viii) Starter Controller. A system is needed to start the engine automatically and then 

shut it off after exactly five minutes of running. A commercial after-market remote 

starting system connected to a timer or computer can be used, or a one-of-a-kind system 

can be designed and built.

(ix) Tech 2 Analyzer. A General Motors Tech 2 analyzer, part number GM3000094, 

available from Kent-Moore, shall be used to conduct the injector balance test.

(x) Fuel Pressure Gauge. A fuel pressure gauge capable of measuring fuel system 

pressure to the nearest 1 psi over the range of 45 to 65 psi, shall be used with the Tech 2 

analyzer when conducting the injector balance test. A pressure transducer shall not be 

used.

(xi) Gaskets. The upper intake manifold gasket and injector body gasket will need to 

be replaced from time to time as they crack, tear, or wear out from frequent handling 

during injector replacement.

(3) Initial Vehicle Preparation – (i) Diagnostics. To help determine whether a vehicle 

is satisfactory for use in this injector test procedure, a thorough inspection and engine 

diagnostic test shall be conducted as described in the service manual. Check the cooling 

system to be sure the coolant looks clean and there are no signs of rust.

(ii) Block Heaters. Install four electric block heaters, General Motors part number 

12371293, in the coolant passages of the engine block, two on each side of the block. 

The heaters will be plugged into a heater control unit. Two of the heaters will remain on 

at all times during the first 144 hours of the injector fouling test, while the other two 

heaters will be turned on and off by the controller as needed to maintain an engine 

temperature of about 100-102°C during the soak periods of the test. (The temperature 

will drop while the engine is running, as the coolant from the radiator circulates through 

the engine. The temperature should recover to 100-102°C within about 20 minutes after 

the engine shuts off.)

(iii) Thermocouples. Install a 1/16-inch Type K thermocouple in a threaded bolt hole 

on the rear of the right cylinder head. This thermocouple provides the feedback signal to 

the controller to turn two block heaters on and off. Install another thermocouple in the 

other hole near the first thermocouple. This second thermocouple provides a signal to an 

over-temperature safety shut-off on the heater controller. If the engine temperature 
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reaches the set point (110°C recommended), the heater controller will signal the starter 

controller to shut down the test.

(iv) Fuel System Flush. Drain the fuel from the fuel system through the service port 

on the fuel rail at the back of the engine. Refuel with a non-detergent gasoline containing 

between 5 and 10 percent ethanol. Drive the vehicle for approximately 100 miles to 

thoroughly expose all parts of the fuel system to the fuel. The fuel pump and fuel filters 

should not be replaced unless there is a problem with them or if the vehicle history

suggests that replacement would be prudent. If replacement is necessary, the new parts 

should first be conditioned by recirculating a 10% ethanol-gasoline blend (without 

deposit control additive) through them for one week.

(v) Oil Change. Change the engine oil and oil filter, using oil that meets the 

manufacturer’s recommended service classification and viscosity grade.

(vi) Battery Charger. Install a battery charger in the vehicle so that it can be plugged 

in during the test and keep the battery at full charge.

(vii) Radiator. Install cardboard or other suitable material on the front of the radiator 

to block the flow of air through the radiator while the engine is running. This will help 

minimize the drop in coolant temperature.

(viii) Starter Controller. Make the necessary changes to the vehicle electrical system so 

that the engine can be started and stopped automatically on a programmed schedule. 

Install a starter controller or computer and program it to do the following:

(A) Start the engine and let it run for 5 minutes, and then shut it off and let it hot-soak 

for 25 minutes.

(B) Repeat the 5/25 cycle for a total of 192 cycles.

(C) Allow a 48-hr hot soak during which the engine is not run but the engine 

temperature is maintained at 100-102°C.

(D) Turn off the heaters for 48 hours.

(E) Continuously count and display the number of cycles that have been completed 

throughout the test.

(4) Test Procedure. The steps described in paragraphs (c)(3)(i) though (vi) of this 

section must be performed by the action described in paragraph (c)(3)(vii) of this section 

so that the new injectors are exposed only to the new test fuel. Take the following 

additional steps:

(i) Drain the fuel from the vehicle.

(ii) Add approximately 2 gallons of the fuel to be tested.

(iii) Drive the vehicle for approximately 20 miles at speeds up to approximately 50-60 

mph. Approximately every 5 miles, stop the vehicle and moderately accelerate. If the 

radiator covering is still in place, watch the temperature gauge during the driving and 

avoid overheating the engine. This step not only flushes the fuel system but also helps 

remove carbon (if any) from the spark plugs and water from the exhaust system.

(iv) Drain the fuel from the vehicle and add approximately 1 to 2 gallons of the fuel to 

be tested.

(v) Drive the vehicle for approximately 5 miles. Watch the temperature gauge and 

avoid overheating the engine.
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(vi) Drain the fuel from the vehicle and add approximately 10 gallons of the fuel to be 

tested. (The test consumes about 7.5 gallons of fuel.)

(vii) Remove the fuel injectors and install new injectors. Run the engine for a few 

minutes to be sure it runs properly.

(viii) Park the vehicle in the location where the test will be run.

(ix) Connect the vehicle tail pipe to the building exhaust system.

(x) Depending on the design of the starter control system, remove fuses and relays as 

necessary and connect the wires from the controller to the vehicle fuse box. Close the 

hood.

(xi) Turn on the vehicle ignition switch and the security bypass switch if so equipped.

(xii) Turn on the heater controller and be sure that it is working.

(xiii) Turn on the starter controller and the vehicle should start.

(xiv) Monitor the engine temperature for the first few cycles to be sure it is increasing.

(xv) At the end of the 192-hour (8-day) test, turn off the ignition switch, starter 

controller, and heater controller. Return the fuses, relays, and wires to their standard 

configuration for normal operation of the vehicle.

(xvi) Connect the Tech 2 analyzer to the ALDL connector under the instrument panel, 

and connect the fuel pressure gauge to the service port on the fuel rail at the back of the 

engine.

(xvii) Conduct the injector balance test by following the instructions on the Tech 2. The 

injector balance test checks each injector individually to determine whether the poppet 

nozzle is stuck closed. First, the Tech 2 turns on the fuel pump momentarily to pressurize 

the fuel system. Then it pulses the injector for a preset interval. If the injector and 

poppet nozzle are working properly, the fuel system pressure will decrease gradually and 

smoothly by about 8 to 10 psi during the pulsing. If the pressure does not decrease, or 

decreases very suddenly but then stops decreasing before the pulsing is done, the poppet 

is stuck closed. This procedure, beginning with pressurizing the fuel system, is carried 

out for each injector.

26. A new § 80.177 is added to subpart G to read as follows:

§ 80.177 Certification test fuels for use with the alternative test procedures and 

standards.

(a) General requirements. This section provides specifications for the test fuels 

required in conjunction with the alternative national generic certification option described 

in § 80.163(a)(1)(iii).

(1) The test fuel characteristics detailed in this section must be reported to EPA in the 

detergent certification letter required pursuant to § 80.161(b)(3).

(2) The levels of the basic fuel parameters specified in this section (ethanol, olefins, 

aromatics, sulfur, and 90% evaporation distillation temperature) must be measured in 

accordance with applicable procedures in § 80.46.
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(3) No detergent-active substance other than the detergent additive package 

undergoing testing may be added to a certification test fuel. Typical nondetergent 

additives, such as antioxidants, corrosion inhibitors, and metal deactivators, may be 

present in the test fuel at the discretion of the additive certifier. In addition, any

nondetergent additives (other than oxygenate compounds) which are commonly blended 

into gasoline and which are known or suspected to affect IVD or PFID formation, or to 

reduce the ability of the detergent in question to control such deposits, should be added to 

the test fuel for certification testing.

(4) Certification test requirements may be satisfied for a detergent additive using 

more than one batch of test fuel, provided that each batch satisfies all applicable test fuel 

requirements under this section.

(5) Unless otherwise required by this section, finished test fuels must conform to the 

requirements for commercial gasoline described in ASTM D4814.

(b) Test fuel for intake valve deposit testing. The following specifications apply for 

the test fuels required for use in the test procedure specified in § 80.176(b):

(1) The test fuel must contain no less than 8.0 volume percent and no more than 10.0 

volume percent ethanol. Commercial fuel grade denatured fuel ethanol must be used that 

conforms to the requirement of § 80.1610 and ASTM D4806.

(2) The test fuel must contain no less than 8.0 volume percent olefins. At least 75 

percent of the olefins must be derived from fluid catalytic cracker unit (FCC) gasoline. 

Such FCC gasoline can be full-range FCC gasoline or a mixture of light and heavy FCC 

gasolines. Such FCC gasoline must be produced by a commercial gasoline refiner and 

meet the following criteria:

(i) The FCC gasoline must be designated by the commercial refiner as full range 

FCC gasoline or whole FCC gasoline, and must have a T90 distillation temperature 

greater than 300°F.

(ii) If a mixture of light and heavy FCC gasoline is used, heavy FCC gasoline must 

contribute at least 50 percent of the sulfur in the mixture. Heavy FCC gasoline must 

meet all the following criteria:

(A) The heavy FCC gasoline must be designated by the commercial refiner as heavy 

FCC gasoline.

(B) The heavy FCC gasoline must have an API gravity less than 45 and a T90 

distillation temperature greater than 325°F.

(3) The test fuel must contain no less than 28 volume percent aromatics.

(4) The test fuel must contain no less than 24 ppm sulfur. At least 60 percent of the 

sulfur must be derived from FCC gasoline that meets the specifications in paragraph 

(b)(2) of this section.

(5) The test fuel must have a T90 distillation temperature of no less than 290°F.

(6) The test fuel containing no deposit control additives must produce no less than 

500 mg averaged over all intake valves when subjected to the intake valve deposit test 

specified in § 80.176(b).

(7) All gasoline blendstocks used to formulate the test fuel must be representative of 

normal refinery operations and shall be derived from conversion units downstream of 
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distillation. Butanes and pentanes may be used for vapor pressure adjustment. The use 

of chemical grade streams is prohibited.

(c) Test fuel for fuel injector deposit testing: This paragraph provides specifications 

for the test fuels required for use in the test procedure specified in § 80.176(c). The test 

fuel must conform to the specifications in either paragraph (c)(1) or (c)(2) of this section. 

The same base test fuel must be used for deposit demonstration testing and for 

demonstrating compliance with the fuel injector deposit control standards in § 80.176(a).

(1) Option 1. (i) The test fuel must be a commercial full boiling range hydrocarbon 

gasoline or gasoline blending component, without oxygenates.

(ii) The test fuel containing no deposit control additives must produce at least 5 

inoperable injectors valves when subjected to the fuel injector deposit test specified in § 

80.176(c).

(2) Option 2. (i) The test fuel must meet the requirements for federal emissions test 

gasoline specified in §§ 80.112 and 80.113 into which 4-methylbenzenethiol has been 

blended as a concentration of 56 mg/L.

(ii) The test fuel containing no deposit control additives must produce at least 4 

inoperable injectors valves when subjected to the fuel injector deposit test specified in § 

80.176(c).

(d) Materials incorporated by reference. The published materials identified in this 

section are incorporated by reference into this section with the approval of the Director of 

the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. To enforce any edition 

other than that specified in this section, a document must be published in the Federal 

Register and the material must be available to the public. All approved materials are 

available for inspection at the Air and Radiation Docket and Information Center (Air 

Docket) in the EPA Docket Center (EPA/ DC) at Rm. 3334, EPA West Bldg., 1301

Constitution Ave. NW., Washington, DC. The EPA/DC Public Reading Room hours of 

operation are 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. 

The telephone number of the EPA/DC Public Reading Room is (202) 566–1744, and the 

telephone number for the Air Docket is (202) 566–1742. These approved materials are 

also available for inspection at the National Archives and Records Administration 

(NARA). For information on the availability of this material at NARA, call (202) 741–

6030 or go to http:// www.archives.gov/federal_register/ code_of_federal_regulations/ 

ibr_locations.html. In addition, these materials are available from the sources listed 

below.

(1) ASTM International material. The following standards are available from ASTM 

International, 100 Barr Harbor Dr., P.O. Box C700, West Conshohocken, PA 19428-

2959, (877) 909–ASTM, or http://www.astm.org;

(i) ASTM D4806-13a, Standard Specification for Denatured Fuel Ethanol for 

Blending with Gasolines for Use as Automotive Spark-Ignition Engine Fuel, approved 

June 15, 2013.

(ii) ASTM D4814–13b, Standard Specification for Automotive Spark-Ignition Engine 

Fuel, approved December 1, 2013.
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(2) [Reserved]

Subpart H—[Amended] 

27. Section 80.330 is amended by revising paragraphs (c)(1) and (d) to read as 

follows:

§ 80.330 What are the sampling and testing requirements for refiners and 

importers?

* * * * *

(c) * * *

(1) For purposes of paragraph (a) of this section, refiners and importers shall use the 

method provided in § 80.46(a)(1) or one of the alternative test methods listed in § 

80.46(a)(3) to measure the sulfur content of gasoline they produce or import through 

December 31, 20. Beginning January 1, 2016, for purposes of paragraph (a) of this 

section, refiners and importers shall use an approved method in § 80.47.

* * * * *

(d) Test method for sulfur in butane. (1) Refiners and importers shall use the method 

provided in § 80.46(a)(2) through December 31, 2015 to measure the sulfur content of 

butane when the butane constitutes a batch of gasoline. Beginning January 1, 2016, 

refiners and importers shall use an approved method in § 80.47 to measure the sulfur 

content of butane when the butane constitutes a batch of gasoline. 

(2) Except as provided in paragraph (d)(1) of this section, any ASTM sulfur test 

method for gaseous fuels may be used for quality assurance testing under §§ 80.340(b)(4) 

and 80.400, if the protocols of the ASTM method are followed and the alternative test 

method is correlated to the method provided in § 80.46(a)(2) through December 31, 20, 

or in § 80.47 beginning January 1, 2016. 

* * * * * 

28. Section 80.340 is amended by revising paragraphs (b)(1) and (d) to read as 

follows:

§ 80.340 What standards and requirements apply to refiners producing gasoline by 

blending blendstocks into previously certified gasoline (PCG)?

* * * * *

(b) * * *

(1) The sulfur content of the butane received from the butane supplier must not exceed 

the following sulfur standards on a per-gallon basis as follows:

(i)(A) 120 ppm in 2004;

(B) 30 ppm from January 1, 2005 through December 31, 2016; and 

(C) 10 ppm on or after January 1, 2017.
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(ii) Except that the per-gallon sulfur content of butane blended to PCG that is designated 

as GPA gasoline shall not exceed 150 ppm from January 1, 2004, through December 31, 

2006.

* * * * *

(d) Refiners who blend only blender-grade pentane into PCG pursuant to the 

requirements of § 80.85 may meet the sampling and testing requirements by using sulfur 

test results of the pentane supplier pursuant to the requirements § 80.85, provided that the 

following requirements are also met:

(1) The sulfur content and volume of each batch of gasoline produced is that of the 

blender-grade pentane the refiner blends into gasoline for purposes of calculating 

compliance with the standards in §§ 80.195 and 80.216.

(2) If any of the requirements of this section are not met, in whole or in part, for any 

pentane blended into gasoline, that pentane is deemed in violation of the gasoline sulfur 

standards in § 80.85, or § 80.86, § 80.195, § 80.216 as applicable.

29. Section 80.370 is amended by:

a. Revising paragraph (a)(7)(iv).

b. Revising paragraph (d)(2).

c. Adding paragraph (e).

d. Revising paragraph (f). 

§ 80.370 What are the sulfur reporting requirements?

* * * * *

(a) * * *

(7) * * *

(iv) The sulfur content of the batch, along with identification of the test method used 

to measure the sulfur content of the batch, as determined under § 80.330; and

* * * * *

(d) * * *

(2) Submitted to EPA by March 31 for the prior calendar year averaging period.

* * * * *

(e) [Reserved]

(f) Attest reports. Attest reports for refiner and importer attest engagements required 

under § 80.415 shall be submitted to the Administrator by June 1 of each year for the 

prior calendar year averaging period.

30. Section 80.385 is amended by revising paragraph (e) to read as follows:
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§ 80.385 What acts are prohibited under the gasoline sulfur program?

* * * * *

(e) Denatured fuel ethanol violation. (1) Through December 31, 2016, blend into 

gasoline any denatured fuel ethanol with a sulfur content higher than 30 ppm.

(2) Beginning January 1, 2017 and thereafter, blend into gasoline any denatured fuel 

ethanol with a sulfur content higher than 10 ppm.

* * * * *

Subpart I—[Amended]

31. Section 80.511 is amended by revising paragraphs (b)(4) and (b)(10) to read as 

follows:

§ 80.511 What are the per-gallon and marker requirements that apply to 

NRLM diesel fuel, ECA marine fuel, and heating oil downstream of the refiner or 

importer?

* * * * *

(b) * * *

(4) Except as provided in paragraphs (b)(5) through (8) of this section, the per-gallon 

sulfur standard of § 80.510(c) shall apply to all NRLM diesel fuel beginning August 1, 

2014 for all downstream locations other than retail outlets or wholesale purchaserconsumer facilities, shall apply to all NRLM diesel fuel beginning October 1, 2014 for 

retail outlets and wholesale purchaser-consumer facilities, and shall apply to all NRLM 

diesel fuel beginning December 1, 2014 for all locations. This paragraph (b)(4) does not 

apply to LM diesel fuel produced from transmix or interface fuel that is sold or intended 

for sale in areas other than those listed in § 80.510(g)(1) or (g)(2), as provided by § 

80.513(f).

* * * * *

(10) For the purposes of this subpart, on any occasion where a distributor directly

dispenses fuel into vehicles or equipment from a mobile facility such as a tanker truck, 

the distributor shall be treated as a retailer, and the mobile facility shall be treated as a 

retail outlet.

32. Section 80.572 is amended by revising paragraph (a) to read as follows:

§ 80.572 What labeling requirements apply to retailers and wholesale 

purchaser-consumers of Motor Vehicle, NR, LM and NRLM diesel fuel and heating 

oil beginning June 1, 2010?

* * * * *
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(a) From June 1, 2010 through November 30, 2014, any retailer or wholesale 

purchaser-consumer who sells, dispenses, or offers for sale or dispensing, motor vehicle 

diesel fuel subject to the 15 ppm sulfur standard of § 80.520(a)(1), must affix the 

following conspicuous and legible label, in block letters of no less than 24-point bold 

type, and printed in a color contrasting with the background, to each pump stand:

ULTRA-LOW SULFUR HIGHWAY DIESEL FUEL (15 ppm Sulfur Maximum)

Required for use in all highway diesel vehicles and engines.

Recommended for use in all diesel vehicles and engines.

* * * * *

33. Section 80.573 is amended by revising paragraph (a) to read as follows:

§ 80.573 What labeling requirements apply to retailers and wholesale 

purchaser-consumers of NRLM diesel fuel and heating oil beginning June 1, 2012?

* * * * *

(a) From June 1, 2012 through September 30, 2014, for pumps dispensing NRLM 

diesel fuel subject to the 15 ppm sulfur standard of § 80.510(c):

ULTRA-LOW SULFUR NON-HIGHWAY DIESEL FUEL (15 ppm Sulfur Maximum)

Required for use in all model year 2011 and later nonroad diesel engines.

Recommended for use in all other non-highway diesel engines.

WARNING

Federal law prohibits use in highway vehicles or engines.

* * * * *

34. Section 80.574 is revised to read as follows:

§ 80.574 What labeling requirements apply to retailers and wholesale 

purchaser-consumers of ECA marine fuel beginning June 1, 2014?

(a) Any retailer or wholesale purchaser-consumer who sells, dispenses, or offers for 

sale or dispensing ECA marine fuel must prominently and conspicuously display in the 

immediate area of each pump stand from which ECA marine fuel is offered for sale or 

dispensing, one of the following legible labels, as applicable, in block letters of no less 

than 24-point bold type, printed in a color contrasting with the background: 

(1) From June 1, 2014 and beyond, for pumps dispensing ECA marine fuel subject to 

the 1,000 ppm sulfur standard of § 80.510(k):

1,000 ppm SULFUR ECA MARINE FUEL (1,000 ppm Sulfur Maximum).

For use in Category 3 (C3) marine vessels only.

WARNING
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Federal law prohibits use in any engine that is not installed on a C3 marine vessel; use of 

fuel oil with a sulfur content greater than 1,000 ppm in an ECA is prohibited except as 

allowed by 40 CFR part 1043.

(2) The labels required by paragraph (a)(1) of this section must be placed on the 

vertical surface of each pump housing and on each side that has gallon and price meters. 

The labels shall be on the upper two-thirds of the pump, in a location where they are 

clearly visible.

(b) Alternative labels to those specified in paragraph (a) of this section may be used 

as approved by EPA. Send requests to–

(1) For US Mail: U.S. EPA, Attn: Diesel Sulfur Alternative Label Request, 6406J, 

1200 Pennsylvania Avenue, NW, Washington, DC 20460.

(2) [Reserved]

35. Section 80.580 is amended by revising paragraph (e) to read as follows:

§ 80.580 What are the sampling and testing methods for sulfur?

* * * * *

(e) Materials incorporated by reference. The published materials identified in this 

section are incorporated by reference into this section with the approval of the Director of 

the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. To enforce any edition 

other than that specified in this section, a document must be published in the Federal 

Register and the material must be available to the public. All approved materials are

available for inspection at the Air and Radiation Docket and Information Center (Air 

Docket) in the EPA Docket Center (EPA/ DC) at Rm. 3334, EPA West Bldg., 1301

Constitution Ave. NW., Washington, DC. The EPA/DC Public Reading Room hours of 

operation are 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. 

The telephone number of the EPA/DC Public Reading Room is (202) 566–1744, and the 

telephone number for the Air Docket is (202) 566–1742. These approved materials are 

also available for inspection at the National Archives and Records Administration 

(NARA). For information on the availability of this material at NARA, call (202) 741–

6030 or go to http:// www.archives.gov/federal_register/ code_of_federal_regulations/ 

ibr_locations.html. In addition, these materials are available from the sources listed 

below.

(1) ASTM International material. The following standards are available from ASTM 

International, 100 Barr Harbor Dr., P.O. Box C700, West Conshohocken, PA 19428-

2959, (877) 909–ASTM, or http://www.astm.org:

(i) ASTM D2622-10, Standard Test Method for Sulfur in Petroleum Products by

Wavelength Dispersive X-ray Fluorescence Spectrometry, approved February 15, 2010.
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(ii) ASTM D4294-10, Standard Test Method for Sulfur in Petroleum and Petroleum 

Products by Energy Dispersive X-ray Fluorescence Spectrometry, approved February 15, 

2010.

(iii) ASTM D5453-12, Standard Test Method for Determination of Total Sulfur in 

Light Hydrocarbons, Spark Ignition Engine Fuel, Diesel Engine Fuel, and Engine Oil by 

Ultraviolet Fluorescence, approved November 1, 2012.

(iv) ASTM D6920-13, Standard Test Method for Total Sulfur in Naphthas, Distillates, 

Reformulated Gasolines, Diesels, Biodiesels, and Motor Fuels by Oxidative Combustion 

and Electrochemical Detection, approved September 15, 2013.

(2) [Reserved]

36. Section 80.585 is amended by revising paragraph (d)(4) to read as follows:

§ 80.585 What is the process for approval of a test method for determining the 

sulfur content of diesel or ECA marine fuel?

* * * * *

(d) * * *

(4) The approval of any test method under paragraph (b) of this section shall be valid 

for five years from the date of approval by the Administrator. After the five year period 

has ceased, in order for the test method approval to remain valid, the test method must be 

resubmitted for approval with applicable precision and accuracy information contained in 

§ 80.584(a) and (b). If, however, the test method is later approved by a voluntary 

consensus-based standards body, the approval shall remain valid as long as the conditions 

of paragraph (a) of this section are met.

* * * * *

37. Section 80.604 is amended by revising paragraphs (f)(3) and (f)(4) to read as 

follows:

§ 80.604 What are the annual reporting requirements for refiners and 

importers of NRLM diesel fuel?

* * * * *

(f) * * *

(3) Except for small refiners subject to § 80.554(d), submitted to EPA by September 

1 each year for the prior annual compliance period. Small refiners subject to the 

provisions of § 80.554(d), reports must be submitted by September 1 for the previous 

reporting period.

(4) With the exception of reports required under paragraph (b)(3) of this section, no 

reports will be required under this section after September 1, 2014.
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Subpart L--[Amended]

38. Section 80.1235 is amended by revising paragraphs (a)(6) and (b)(2) to read as 

follows:

§ 80.1235 What gasoline is subject to the benzene requirements of this subpart?

(a) * * *

(6) Blendstock that is combined with PCG to produce gasoline must be sampled and 

tested in accordance with the provisions at § 80.1347(a)(5) or (6).

(b) * * *

(2) Oxygenate added to PCG downstream of the refinery that produced the PCG, or 

downstream of the import facility where the PCG was imported, shall not be included in a 

refiner’s or importer’s compliance calculations unless the refiner or importer that 

produced or imported the PCG complies with the requirements of § 80.1238(b). On any 

occasion where any person downstream of the refinery or importer that produced or 

imported PCG adds oxygenate to such product, it shall not include the volume and 

benzene content of the oxygenate in any compliance calculations or for credit generation 

under this subpart.

* * * * *

39. Section 80.1238 is amended by revising paragraph (b)(1) to read as follows:

§ 80.1238 How is a refinery’s or importer’s average benzene concentration 

determined?

* * * * *

(b) * * *

(1) For oxygenate added to conventional gasoline or CBOB, the refiner or importer 

must comply with the requirements of § 80.101(d)(4)(ii). The benzene content of 

theoxygenate must be determined using the applicable test method at § 80.46 through 

December 31, 2015, and at § 80.47 beginning January 1, 2016. 

* * * * *

40. Section 80.1347 is amended by revising paragraphs (a)(3)(i) and (a)(5) and adding 

paragraph (a)(6) to read as follows:

§ 80.1347 What are the sampling and testing requirements for refiners and 

importers?
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(a) * * *

(3)(i) Each sample shall be tested in accordance with the methodology specified at § 

80.46(e) through December 31, 2015, to determine its benzene concentration for 

compliance with the requirements of this subpart. Beginning January 1, 2016, each 

sample shall be tested in accordance with the methodology specified at § 80.47 to 

determine its benzene concentration for compliance with the requirements of this subpart. 

Any negative test result must be reported as zero.

* * * * *

(5) Previously certified gasoline (PCG) may be excluded as follows:

(i) Any refiner who uses PCG to produce gasoline at a refinery, must exclude the 

PCG for purposes of demonstrating compliance with the benzene standards at § 80.1230.

(ii) To accomplish the exclusion required in paragraph (a)(5)(i) of this section, the 

refiner must determine the volume and benzene content of the PCG used at the refinery

and the volume and benzene content of gasoline produced at the refinery, and use the 

compliance calculation procedures in paragraphs (a)(5)(iii) and (iv) of this section.

(iii) For each batch of PCG that is used to produce gasoline the refiner must include 

the volume and benzene content of the PCG as a negative volume and a positive benzene 

content in the refiner’s compliance calculations in accordance with the requirements at § 

80.1238.

(iv) For each batch of gasoline produced at the refinery using PCG and blendstock, the 

refiner must determine the volume and benzene content of the combined product and 

include each batch for purposes of benzene compliance in the refinery’s compliance 

calculations at § 80.1240 without regard to the presence of previously certified gasoline 

in the batch.

(v) The refiner must use any PCG that it includes as a negative batch in its 

compliance calculations pursuant to § 80.1240 as a component in gasoline production 

during the annual averaging period in which the PCG was included as a negative batch in 

the refiner’s compliance calculations.

(vi) Any negative annual average value must be reported as zero.

(vii) The refiner must also comply with § 80.65(i) when producing RBOB or RFG and 

§ 80.101(g)(9) when producing conventional gasoline.

(6) As an alternative to the sampling and testing requirements in paragraph (a)(5) of 

this section, a refiner who produces gasoline by blending one or more blendstocks into 

PCG may sample and test each batch of blendstock when received at the refinery to 

determine the volume and benzene content, and treat each blendstock receipt as a 

separate batch for purposes of demonstrating compliance with the benzene standards in § 

80.1230, and for benzene reporting.

* * * * *

41. Section 80.1348 is revised to read as follows: 

§ 80.1348 What gasoline sample retention requirements apply to refiners and 

importers?
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(a) Through December 31, 2015, the gasoline sample retention requirements 

specified in subpart H of this part for the gasoline sulfur provisions apply for the purpose 

of complying with the requirements of this subpart L, except that in addition to including 

the sulfur test result as provided by § 80.335(a)(4)(ii), the refiner, importer, or 

independent laboratory shall also include with the retained sample the test result for 

benzene as conducted pursuant to § 80.46(e).

(b) Beginning January 1, 2016, pursuant to § 80.47, the gasoline sample retention 

requirements specified in subpart O of this part for the gasoline sulfur provisions apply

for the purpose of complying with the requirements of this subpart L, except that in 

addition to including the sulfur test result as provided by § 80.335(a)(4)(ii), the refiner, 

importer, or independent laboratory shall also include with the retained sample the test 

result for benzene as conducted pursuant to § 80.47.

42. A new § 80.1349 is added to subpart L to read as follows:

§ 80.1349 Alternative sampling and testing requirements for importers who import 

gasoline into the United States by truck.

Importers who import conventional gasoline into the United States by truck may comply

with the sampling and testing requirements in § 80.101(i)(3) instead of the requirements 

to sample and test every batch of gasoline under § 80.1347. An importer that uses this 

approach must meet the 0.62 volume percent benzene standard on a per-gallon basis. 

43. Section 80.1354 is amended by revising paragraphs (b)(2) and (d)(2) to read as 

follows:

§ 80.1354 What are the reporting requirements for the gasoline benzene program?

* * * * *

(b) * * *

(2)(i) The annual average benzene concentration, per § 80.1238, along with 

identification of the test method(s) used to measure the annual average benzene 

concentration.

(ii) The maximum average benzene concentration, per § 80.1240(b), along with 

identification of the test method(s) used to measure the maximum average benzene 

concentration.

* * * * *

(d) * * *

(2) Submitted to EPA by March 31 each year for the prior calendar year averaging 

period.
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* * * * *

Subpart M--[Amended] 

44. Section 80.1407 is amended by revising paragraph (c)(5) to read as follows:

§ 80.1407 How are the Renewable Volume Obligations calculated?

* * * * *

(c) * * *

(5) Blendstock (including butane, pentane, and gasoline treated as blendstock 

(GTAB)) that has been combined with other blendstock and/or finished gasoline to 

produce gasoline.

* * * * *

45. Section 80.1451 is amended by revising paragraphs (a)(1) introductory text and 

(f)(2) to read as follows:

§ 80.1451 What are the reporting requirements under the RFS program?

(a) * * *

(1) Annual compliance reports for the previous compliance period shall be submitted 

by March 31 of each year, except as provided in paragraph (a)(1)(xiv) of this section, and 

shall include all the following information:

* * * * * 

(f) * * *

(2) Quarterly reports shall be submitted by the required deadline as shown in Table 1 

of this section. Any reports generated by EMTS must be reviewed, supplemented, and/or 

corrected if not complete and accurate, and verified by the owner or responsible corporate 

officer prior to submittal. Table 1 follows:

Table 1 to § 80.1451: Quarterly Reporting Deadlines

Calendar Quarter Time Period Covered Quarterly Report 

Deadline

Quarter 1 January 1 - March 31 June 1

Quarter 2 April 1 – June 30 September 1

Quarter 3 July 1 – September 30 December 1

Quarter 4 October 1 – December 31 March 31

* * * * * 
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46. Section 80.1464 is amended by revising paragraph (d) to read as follows:

§ 80.1464 What are the attest engagement requirements under the RFS program?

* * * * *

(d) For each compliance year, each party subject to the attest engagement 

requirements under this section shall cause the reports required under this section to be 

submitted to EPA by June 1 of the year following the compliance year, except as 

provided in paragraph (g) of this section.

* * * * *

47. A new subpart O is added to part 80 to read as follows:

Subpart O—Gasoline Sulfur

Sec.

80.1600 Additional definitions for subpart O.

80.1601 Fuels subject to the provisions of this subpart.

80.1602 Applicability.

80.1603 Gasoline sulfur standards for refiners and importers.

80.1604 Gasoline sulfur standards and requirements for parties downstream of 

refiners and importers.

80.1605 Deficit carryforward for refiners and importers.

80.1606 [Reserved]

80.1607 Gasoline sulfur standards and requirements for transmix processors and 

transmix blenders.

80.1608 [Reserved]

80.1609 Oxygenate blender requirements.

80.1610 Standards and requirements for producers and importers of denatured fuel 

ethanol and other oxygenates designated for use in transportation fuel.

80.1611 Standards and requirements for certified ethanol denaturant. 

80.1612 [Reserved]

80.1613 Standards and other requirements for gasoline additive manufacturers and 

blenders.

80.1614 [Reserved]

80.1615 Credit generation.

80.1616 Credit use and transfer.

80.1617—80.1619 [Reserved]

80.1620 Small refiner definition.

80.1621 Small volume refinery definition.

80.1622 Approval for small refiner and small volume refinery status.

80.1623—80.1624 [Reserved]
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80.1625 Hardship provisions.

80.1626—80.1629 [Reserved]

80.1630 Sampling and testing requirements for refiners and importers.

80.1631 Gasoline, RBOB, and CBOB sample retention requirements.

80.1632—80.1639 [Reserved]

80.1640 Standards and requirements that apply to refiners producing gasoline by

blending blendstocks into previously certified gasoline (PCG).

80.1641 Alternative sulfur standards and requirements that apply to importers who 

transport gasoline by truck.

80.1642 Sampling and testing requirements for producers and importers of 

denatured fuel ethanol and other oxygenates for use by oxygenate blenders.

80.1643 Sample retention requirements for producers and importers of denatured 

fuel ethanol.

80.1644 Sampling and testing requirements for producers and importers of ethanol 

denaturant designated as suitable for the manufacture of denatured fuel ethanol meeting 

federal quality requirements.

80.1645 Sample retention requirements for producers and importers of denaturant 

designated as suitable for the manufacture of denatured fuel ethanol meeting federal 

quality requirements.

80.1646—80.1649 [Reserved]

80.1650 Registration.

80.1651 Product transfer document requirements.

80.1652 Reporting requirements for gasoline refiners, gasoline importers, 

oxygenate producers, and oxygenate importers.

80.1653 Recordkeeping.

80.1654 California gasoline requirements.

80.1655 National security exemption.

80.1656 Exemptions for gasoline used for research, development, or testing 

purposes.

80.1657 [Reserved]

80.1658 Requirements for gasoline for use in American Samoa, Guam, and the 

Commonwealth of the Northern Mariana Islands.

80.1659 [Reserved]

80.1660 Prohibited acts.

80.1661 What evidence may be used to determine compliance with the prohibitions 

and requirements of this subpart and liability for violations of this subpart?

80.1662 Liability for violations.

80.1663 Defenses for a violation of a prohibited act.

80.1664 [Reserved]

80.1665 Penalties.

80.1666 Additional requirements for foreign small refiners and foreign small 

volume refineries.

80.1667 Attest engagement requirements.
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Subpart O—Gasoline Sulfur

§ 80.1600 Additional definitions for subpart O.

The definitions of § 80.2 and the following additional definitions apply to this subpart O:

California gasoline means any gasoline designated by a refiner or importer for use in 

California.

Certified ethanol denaturant means ethanol denaturant that meets the requirements of § 

80.1611.

Certified Sulfur-FRGAS has the meaning given in § 80.1666(a)(5).

Denatured fuel ethanol (DFE) means an alcohol of the chemical formula C2H6O which 

contains a denaturant to make it unfit for human consumption, that is produced or 

imported for use in motor gasoline, and that meets the requirements of § 80.1610.

Ethanol denaturant means previously certified gasoline (including previously certified 

blendstocks for oxygenate blending), gasoline blendstocks, or natural gasoline liquids 

that are added to neat (un-denatured) ethanol to make it unfit for human consumption in 

accordance with the requirements of the Alcohol and Tobacco Tax and Trade Bureau of 

the U.S. Treasury Department.

Foreign refiner is a person who meets the definition of refiner under § 80.2(i) for a 

foreign refinery.

Foreign refinery means a refinery that is located outside the United States. Note that the 

United States includes the Commonwealth of Puerto Rico, the Virgin Islands, Guam, 

American Samoa, and the Commonwealth of the Northern Mariana Islands.

Non-Certified Sulfur-FRGAS has the meaning given in § 80.1666(a)(6).

Non-Sulfur-FRGAS has the meaning given in § 80.1666(a)(4).

Sulfur-FRGAS has the meaning given in § 80.1666(a)(3).

Transmix has the meaning given at § 80.84(a)(2).

Transmix blender has the meaning given at § 80.84(a)(7).

Transmix gasoline product (TGP) has the meaning given at § 80.84(a)(3).

Transmix processing facility has the meaning given at § 80.84(a)(4).
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Transmix processor has the meaning given at § 80.84(a)(5).

§ 80.1601 Fuels subject to the provisions of this subpart.

(a) For the purposes of this subpart, the following fuels are subject to the standards 

and requirements of this subpart:

(1) Reformulated and conventional gasoline and RBOB, and CBOB (collectively

called “gasoline” unless otherwise specified).

(2) Any blendstock blended with PCG, as defined in § 80.2(d). (3) Oxygenates 

blended with gasoline, RBOB, or CBOB. 

(b) For the purposes of this subpart, the following fuels are not subject to the 

standards and requirements of this subpart:

(1) Gasoline that is used to fuel aircraft, racing vehicles or racing boats that are used 

only in sanctioned racing events, provided that–

(i) Product transfer documents associated with such gasoline, and any pump stand 

from which such gasoline is dispensed, identify the gasoline either as gasoline that is 

restricted for use in aircraft, or as gasoline that is restricted for use in racing motor 

vehicles or racing boats that are used only in sanctioned racing events;

(ii) The gasoline is completely segregated from all other gasoline throughout 

production, distribution and sale to the ultimate consumer; and

(iii) The gasoline is not made available for use as motor vehicle gasoline, or dispensed 

for use in motor vehicles, except for motor vehicles used only in sanctioned racing 

events.

(2) California gasoline as defined in § 80.1600 subject to the provisions of § 80.1654.

(3) Gasoline that is exported for sale and use outside the United States.

(4) Exempt fuels under §§ 80.1655 (national security exemptions), 80.1656 (gasoline 

used for research, development, or testing purposes), and 80.1658 (gasoline used in 

American Samoa, Guam, and the Northern Mariana Islands).

§ 80.1602 Applicability.

(a) The provisions of this subpart O shall apply beginning January 1, 2017, unless 

otherwise provided. 

(b) The standards and requirements for gasoline sulfur under subpart H of this part 

shall continue to apply until the gasoline produced or imported by any refiner or importer 

is required to comply with the standards and requirements under this subpart O.

§ 80.1603 Gasoline sulfur standards for refiners and importers.
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(a) Sulfur standards. (1) Annual average standard. (i) The refinery or importer 

annual average gasoline sulfur standard is 10.00 parts per million (ppm) or milligrams per 

kilogram (mg/kg), except as provided in paragraph (a)(1)(iii) of this section.

(ii) The averaging period is a calendar year (January 1 through December 31).

(iii) The refinery or importer annual average gasoline sulfur standard is the maximum 

average sulfur level allowed for gasoline produced at a refinery or imported by an 

importer during each calendar year beginning January 1, 2017, except as provided by the 

following:

(A) The credit use provisions of § 80.1616.

(B) Beginning January 1, 2020, for small refiners and small volume refineries 

approved pursuant to the provisions of § 80.1622. Small refiners and small volume 

refineries will continue to be subject to the provisions of subpart H of this part through 

December 31, 2019 (or until compliance with this subpart O begins).

(C) Fuels not subject to the standards and requirements of this subpart O as specified 

in § 80.1601(b).

(iv) The annual average sulfur level is calculated in accordance with paragraph (c) of 

this section.

(2) Per-gallon cap standard. (i) The refinery or importer per-gallon cap standard is 80 

ppm, on a per-gallon basis except as otherwise provided by this section.

(ii) The per-gallon cap of paragraph (a)(2)(i) of this section is the maximum sulfur 

level allowed for any batch of gasoline produced at a refinery or imported by an importer 

beginning January 1, 2017, except for fuels not subject to the standards and requirements 

of this subpart O as specified in § 80.1601(b).

(3) Use of Credits. The refinery or importer annual average gasoline sulfur standard 

may be met using credits as provided under § 80.1616. Credits cannot be used to meet 

the applicable per-gallon standard.

(b) [Reserved]

(c) Calculation of the annual average sulfur level. (1) The annual refinery or 

importer average gasoline sulfur level is calculated as follows:

Where:

Sa = The refinery or importer annual average sulfur level, in ppm (mg/kg).

Vi = The volume of gasoline produced or imported in batch i, in gallons.

Si = The sulfur content of batch i determined under § 80.1630, in ppm (mg/kg).

n = The number of batches of gasoline produced or imported during the averaging 

period.

i = Individual batch of gasoline produced or imported during the averaging period.
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(2) The annual average sulfur level calculation in paragraph (c)(1) of this section 

shall be conducted to two decimal places using the rounding procedure specified in § 

80.9.

(d) Oxygenate added downstream from the refinery or import facility. A refiner or 

importer may include oxygenate added downstream from the refinery or import facility

when calculating the sulfur content of a batch, provided that the following requirements 

are met:

(1) For oxygenate added to reformulated gasoline, RBOB, conventional gasoline, or 

CBOB, the refiner or importer shall calculate the sulfur content of the batch by volume 

weighting the sulfur content of the conventional gasoline or CBOB and the sulfur content 

of the added oxygenate pursuant to the following requirements:

(i) The sulfur content of any reformulated gasoline, RBOB, conventional gasoline, or 

CBOB shall be determined by sampling and testing each batch pursuant to § 80.46 or § 

80.47 as applicable.

(ii) For each complete annual compliance period, the sulfur content of all the 

oxygenate added downstream of the refinery or import facility shall be determined by one 

of the following methods:

(A) Testing the sulfur content of a sample of the oxygenate pursuant to § 80.46 or § 

80.47, as applicable. The refiner or importer must demonstrate through records relating 

to sampling, testing, and blending that the test result was derived from a representative 

sample of the oxygenate that was blended with the batch of gasoline or BOB.

(B) If the oxygenate is denatured fuel ethanol, the sulfur content may be assumed to 

be 5.00 ppm.

(iii) For denatured fuel ethanol, the refiner or importer may assume that the denatured 

fuel ethanol was blended with gasoline or BOB at a concentration of 10 volume percent, 

unless the refiner or importer can demonstrate that a different amount of denatured fuel 

ethanol was actually blended with a batch of gasoline or BOB.

(iv) The refiner or importer of conventional gasoline or CBOB must comply with the 

requirements of § 80.101(d)(4)(ii).

(v) The refiner or importer of reformulated gasoline or RBOB must comply with the 

requirements of § 80.69(a).

(vi) Any reformulated gasoline, RBOB, conventional gasoline, or CBOB must meet 

the per-gallon sulfur standard of paragraph (a)(2) of this section prior to calculating any 

dilution from the oxygenate added downstream.

(vii) The reported volume of the batch is the combined volume of the reformulated 

gasoline, RBOB, conventional gasoline, or CBOB and the downstream added oxygenate.

(2) The refiner or importer who first certifies the gasoline, CBOB, or RBOB is the 

only person who may account for the downstream addition of oxygenate pursuant to the 

requirements of paragraph (d) of this section. On any occasion where any person 

downstream of the refinery or importer that produced or imported previously certified 

gasoline, CBOB or RBOB adds oxygenate to such product, it shall not include the 

volume and sulfur content of the oxygenate in any compliance calculations or for credit 

generation under this subpart O.
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(e) Exclusions. Refiners and importers must exclude from compliance calculations 

all the following:

(1) Gasoline that was not produced at the refinery or imported by the importer.

(2) In the case of an importer, gasoline that was imported as Certified Sulfur-FRGAS.

(3) Blendstocks transferred to others, except RBOB and CBOB as provided in this 

subpart O.

(4) Previously certified gasoline (PCG).

(5) Gasoline exempted from standards under § 80.1601(b).

(f) Compliance calculation for the annual average sulfur standard. (1) Compliance 

by a refinery or importer with the gasoline sulfur annual average standard at paragraph 

(a)(1) of this section is achieved if, for calendar year y, the compliance sulfur value is less 

than or equal to 10 times the total gasoline volume produced or imported, as determined 

by the following equation:

CSVy = (Vy x Sa) + D(y-1) – OC

Where:

CSVy = Compliance sulfur value for year y, in ppm-gallons.

Vy = Total gasoline volume produced or imported in year y, in gallons.

Sa = Annual average sulfur level calculated in accordance with paragraph (c) of 

this section, in ppm (mg/kg).

D(y-1) = Sulfur deficit from the previous reporting period, per § 80.1605, in ppmgallons.

OC = Sulfur credits obtained by the refinery or importer, in ppm-gallons.

(2) Sulfur credits used in the calculation specified in paragraph (f)(1) of this section 

must be used in accordance with the requirements at § 80.1616.

(3) Compliance with the gasoline sulfur annual average standard at paragraph (a)(1) 

of this section is not achieved, and a deficit is created per § 80.1605, if for calendar year 

y, the compliance sulfur value is greater than 10 times the total gasoline volume produced 

or imported. The deficit value to be included in the following year's compliance 

calculation per paragraph (f) of this section is calculated as follows:

Dy = CSVy – (Vy x 10y)

Where:

Dy = Sulfur deficit created in compliance period y, in ppm-gallons.

§ 80.1604 Gasoline sulfur standards and requirements for parties downstream of 

refiners and importers.
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(a) The sulfur standard for gasoline at any downstream location shall be determined 

in accordance with the provisions of this section. A downstream location is any point in 

the gasoline distribution system downstream from refineries and import facilities, 

including, but not limited to, facilities of any of the following parties:

(1) Distributors.

(2) Carriers.

(3) Oxygenate blenders.

(4) Retailers.

(5) Wholesale purchaser-consumers.

(b) Except as otherwise provided in this subpart O, the sulfur content of gasoline at 

any downstream location shall not exceed 95 ppm, on a per-gallon basis, beginning 

January 1, 2017.

§ 80.1605 Deficit carryforward for refiners and importers.

(a) Deficit carryforward. A refiner or importer may exceed the annual average sulfur 

standard for a given calendar year, creating a compliance deficit, provided that, in the 

calendar year following the year the standard is not met, the refinery or importer–

(1) Achieves compliance with the annual average sulfur standard in § 80.1603(a)(1); 

and

(2) Uses additional sulfur credits sufficient to offset the compliance deficit of the 

previous year.

(b) The compliance deficit value shall be calculated in accordance with § 

80.1603(f)(3).

§ 80.1606 [Reserved] 

§ 80.1607 Gasoline sulfur standards and requirements for transmix processors and 

transmix blenders.

Transmix processors and transmix blenders may comply with the following sampling and 

testing requirements and standards instead of the sampling and testing requirements and 

standards otherwise applicable to a refiner under this subpart O.

(a) Any transmix processor who recovers transmix gasoline product (TGP) from 

transmix through transmix processing under § 80.84(c) must show through sampling and 

testing (using the methods in § 80.1630) that the TGP meets the applicable sulfur 

standards under § 80.1604(b), prior to the TGP leaving the transmix processing facility.
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(b) The sampling and testing required under paragraph (a) of this section shall be 

conducted following each occasion TGP is produced.

(c) Any transmix processor who produces gasoline by adding blendstock to TGP 

must, for such blendstock, comply with all requirements and standards that apply to a 

refiner under this subpart O, and must meet the downstream sulfur standards under § 

80.1604 for the gasoline produced by blending blendstock and TGP, prior to the gasoline 

leaving the transmix processing facility.

(d) Any transmix processor who produces gasoline by blending blendstock into TGP 

must meet the sampling and testing requirements of this subpart O using one of the

following methods:

(1) Option 1. (i) Sample and test the blendstock that will be added to TGP during 

the compliance year when received at the transmix processing facility, using the methods 

specified in § 80.1630, to determine the volume and sulfur content, and treat each volume 

of blendstock that is blended into a volume of TGP as a separate batch for purposes of 

calculating and reporting compliance with the applicable annual average and per-gallon 

cap sulfur standards in § 80.1603.

(ii) Use sulfur test results of the blendstock supplier provided that all the following 

requirements are met:

(A) Sampling and testing by the blendstock supplier is performed using the methods 

specified in § 80.1630.

(B) Testing for the sulfur content of the blendstock in the supplier’s storage tank must 

be conducted following the last receipt of blendstock into the supplier's storage tank that 

supplies the transmix processor.

(C) The transmix processor must obtain a copy of the blendstock supplier’s test 

results, reflecting the sulfur content of each load of blendstock supplied to the transmix 

processor, at the time of each transfer of blendstock to the transmix processor.

(D) The transmix processor must conduct a quality assurance program of sampling 

and testing for each blendstock supplier. The frequency of blendstock sampling and 

testing must be one sample for every 500,000 gallons of blendstock received or one 

sample every 3 months, whichever results in more frequent sampling.

(iii) If any of the requirements of paragraph (d)(1)(ii) of this section are not met, in 

whole or in part, for any blendstock blended into TGP, the gasoline produced with that 

blendstock is deemed in violation of the gasoline sulfur standards of this subpart O.

(2) Option 2. (i) Sample and test each batch of TGP and determine the volume of the 

TGP.

(ii) Sample and test the gasoline produced by blending blendstock into TGP, and 

determine its volume.

(iii) Calculate the sulfur content and the volume of the batch by subtracting the 

volume and sulfur content of the TGP from the volume and sulfur content of the gasoline 

after blendstock blending. For purposes of compliance and reporting, the sulfur content 

shall be the calculated volume and sulfur content of the blendstock, and the applicable 
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standards shall be the average and cap standards in § 80.1603. The applicable cap 

standard of the gasoline blend shall be the cap standard under § 80.1604.

(iv) Tests shall be performed using the methods specified in § 80.1630, to determine 

the sulfur content of the batch. 

(v) The sulfur content of each batch of gasoline produced by blending blendstock into 

TGP must be no greater than the downstream sulfur standard under § 80.1604 applicable 

to the designation of the TGP.

(e) Any transmix blender who produces gasoline by blending transmix, or mixtures 

of gasoline and distillate fuel described in § 80.84(e), into previously certified gasoline 

under § 80.84(d) must meet the applicable downstream sulfur standards under § 80.1604 

for the gasoline produced by blending transmix and previously certified gasoline and the 

endpoint standard specified in § 80.84.

(f) Any transmix processor or transmix blender who adds any feedstock to its 

transmix other than gasoline, distillate fuel, or gasoline blendstocks from pipeline 

interface must meet all requirements and standards that apply to a refiner under this 

subpart O for all gasoline it produces during a compliance period.

§ 80.1608 [Reserved]

§ 80.1609 Oxygenate blender requirements. 

(a) Oxygenate blenders who blend only oxygenate that complies with the 

requirements of paragraph (b) of this section into gasoline downstream of the refinery

that produced the gasoline or the import facility where the gasoline was imported are not 

subject to the refiner or importer requirements of this subpart for such gasoline, but are 

subject to the requirements and prohibitions applicable to downstream parties in this 

subpart. Such oxygenate blenders are subject to the requirements of paragraph (b) of this 

section, the requirements and prohibitions applicable to downstream parties, the 

requirements of § 80.1603(d)(4), and the prohibition specified in § 80.1660(e).

(b) Beginning January 1, 2017, the DFE or other oxygenate used must comply with 

the requirements of § 80.1610 and all of the other requirements of Subart O. Prior to 

January 1, 2017, DFE is subject to the sulfur requirements of § 80.385(e). 

§ 80.1610 Standards and requirements for producers and importers of 

denatured fuel ethanol and other oxygenates designated for use in transportation 

fuel.
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Beginning January 1, 2017, producers and importers of denatured fuel ethanol (DFE) or 

other oxygenates designated for use in transportation fuel must comply with the 

following requirements:

(a) Standards. (1) The sulfur content must not be greater than 10 ppm.

(2) The DFE or other oxygenate must be composed solely of carbon, hydrogen, 

nitrogen, oxygen and sulfur.

(3) In the case of DFE, only previously certified gasoline (including previously 

certified blendstocks for oxygenate blending), gasoline blendstocks, or natural gas liquids 

may be used as denaturants. 

(4) The concentration of all denaturants used in DFE is limited to a maximum of 3.0 

volume percent.

(b) Registration. Unless registered under § 80.1450, the producer or importer of DFE 

or other oxygenate must register with EPA pursuant to the requirements of § 80.1650. 

(c) PTDs. In addition to any other product transfer document requirements under this 

part, on each occasion when any person transfers custody or title to any oxygenate 

upstream of any oxygenate blending facility, the transferor shall provide to the transferee 

product transfer documents which include the following information: 

(1) For DFE, “Denatured fuel ethanol, maximum 10 ppm sulfur.”; or

(2) For oxygenates other than DFE, The name of the specific oxygenate must be 

identified on the PTD, followed by “maximum 10 ppm sulfur”. 

(3) PTDs that are complaint with the requirements in paragraph (c) of this section 

must be transferred from each party transferring oxygenate to each party that receives 

oxygenate through to the oxygenate blender. 

(4) Alternative PTD language to that specified in paragraphs (c)(1) and (2) of this 

section may be used as approved by EPA.

(d) Batch numbers. Every batch of oxygenate produced or imported at oxygenate 

production or import facility shall be assigned a number (the “batch number”), consisting 

of the EPA-assigned oxygenate producer or importer registration number, the EPA 

facility registration number, the last two digits of the year in which the batch was 

produced, and a unique number for the batch, beginning with the number one for the first 

batch produced or imported each calendar year and each subsequent batch during the 

calendar year being assigned the next sequential number (e.g., 4321–54321–95–000001, 

4321–54321–95–000002, etc.). An alternative batch numbering protocol may be used as 

approved by the Administrator. 

(e) Annual Reports. Submit annual reports to EPA pursuant to the requirements of § 

80.1652.

§ 80.1611 Standards and requirements for certified ethanol denaturant.
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Producers and importers of ethanol denaturant that is suitable for the manufacture of 

denatured fuel ethanol (DFE) meeting federal quality requirements may designate the 

denaturant as certified ethanol denaturant if the following requirements are met.

(a) Standards. (1) The sulfur content must not be greater than 330 ppm as determined 

in accordance with the test requirements of § 80.1630. If the denaturant manufacturer 

represents a batch of denaturant as having a sulfur content of less than 330 ppm in the 

PTD, then the actual sulfur content must be no greater than the stated value as determined 

in accordance with the requirements of § 80.1644. 

(2) The ethanol denaturant must be composed solely of carbon, hydrogen, nitrogen, 

oxygen and sulfur.

(3) Only previously certified gasoline (including previously certified blendstocks for 

oxygenate blending), gasoline blendstocks, or natural gas liquids may be used as 

denaturants.

(b) Registration. Unless registered under § 80.76, § 80.103, or § 80.1450, the 

producer or importer of ethanol denaturant must register with EPA pursuant to the 

requirements of § 80.1650.

(c) PTDs. In addition to any other product transfer document requirements under this 

part 80, on each occasion when any person transfers custody or title to any ethanol 

denaturant designated as suitable for the production of DFE meeting federal quality

requirements upstream of a DFE production or import facility, the transferor shall 

provide to the transferee product transfer documents which include all the following 

information. 

(1) The following statement: “Certified Ethanol Denaturant suitable for use in the 

manufacture of denatured fuel ethanol meeting EPA standards.”.

(2) If the certified ethanol denaturant manufacturer represents that a batch of ethanol 

denaturant has sulfur content less than 330 ppm, then either the actual sulfur content of 

the denaturant must be clearly stated on the PTD, or the PTD must state the sulfur content 

is 330 ppm or less.

(3) Alternative PTD language to that specified in paragraph (c)(1) of this section may 

be used as approved by EPA.

(d) Batch numbers. Every batch of certified ethanol denaturant produced or imported 

at oxygenate production or import facility shall be assigned a number (the “batch 

number”), consisting of the EPA-assigned ethanol denaturant producer or importer 

registration number, the EPA facility registration number, the last two digits of the year 

in which the batch was produced, and a unique number for the batch, beginning with the 

number one for the first batch produced or imported each calendar year and each 

subsequent batch during the calendar year being assigned the next sequential number 

(e.g. 4321–54321–95–000001, 4321–54321–95–000002, etc.).

§ 80.1612 [Reserved]
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§ 80.1613 Standards and other requirements for gasoline additive manufacturers 

and blenders.

Gasoline additive manufacturers and blenders must meet the following requirements:

(a) Gasoline additive manufacturers, as defined in 40 CFR 79.2(f), who manufacture 

additives with a maximum allowed treatment rate of 1.0 volume percent or less must 

meet all the following requirements:

(1) The additive must contribute no more than 3 ppm on a per gallon basis to the 

sulfur content of gasoline when used at the maximum recommended treatment rate.

(2) The additive manufacturer must maintain records of its additive production 

quality control activities which demonstrates that the sulfur content of additive 

production batches complies with the sulfur requirement in paragraph (a)(1) of this 

section and make these records available to EPA upon request.

(3) The maximum treatment rate on the product transfer document for the additive 

must state all the following:

(i) The maximum registered concentration.

(ii) The maximum allowed treatment rate which corresponds to the maximum 

registered concentration. The maximum allowed concentration must be less than 1.0% 

by volume.

(b) Any person who blends an additive that meets the requirements of paragraph (a) 

in this section into PCG is not subject to any requirement of this subpart O, except the 

downstream gasoline sulfur standard of § 80.1604(b) and the prohibition in § 80.1660(f) , 

if all the following conditions are met:

(1) The person blends the additive to PCG at a concentration of less than 1.0% by

volume.

(2) The person does not add any other blendstock or additive except for oxygenates 

meeting the requirements of § 80.1610 and additives meeting the requirements of this 

section to PCG.

(c) Any person who blends any additive that does not meet the requirements of 

paragraphs (a) and (b) of this section, is subject to all of the requirements of this subpart 

O, including the standards and requirements at § 80.1640 that apply to refiners producing 

gasoline by blending blendstocks into PCG.

(d) Oxygenates subject to the 10 ppm per-gallon sulfur standard and the requirements 

of § 80.1610 are not subject to the provisions of this section. On any occasion where the 

additive blender is solely acting as an oxygenate blender, as defined in § 80.2(mm), it is 

subject to the downstream gasoline sulfur standard of § 80.1604(b) and the prohibition in 

§ 80.1660(e).
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§ 80.1614 [Reserved]

§ 80.1615 Credit generation.

(a) Any of the following entities may generate credits under this subpart O:

(1) U.S. refiners, including small refiners under § 80.1620, and refiners owning small 

volume refineries under § 80.1621.

(2) Importers.

(3) Credits may not be generated by transmix processors, producers or blenders of 

ethanol and other oxygenates, butane blenders using the flexibilities in § 80.82, or 

pentane blenders using the flexibilities in § 80.85.

(b) Beginning with the 2014 annual averaging period, the number of credits generated 

for use in complying with the annual average standards of either subpart H of this part or 

§ 80.1603(a) shall be calculated annually for each applicable averaging period according 

to the following equation (pursuant to § 80.310):

CRa = Va × (SCredit − Sa)

Where:

CRa = Credits generated for the averaging period.

Va = Total annual volume of gasoline produced at a refinery or imported during 

the averaging period.

SCredit =30.00 ppm.

Sa = Actual annual average sulfur level, calculated in accordance with the 

provisions of § 80.205, for gasoline produced at a refinery or imported during the 

averaging period, exclusive of any credits. The value of Sa must be less than 30.00.

(c) Except as provided in paragraph (d) of this section, beginning with the 2017 

annual averaging period, the number of credits generated for use in complying with the 

annual average standards of § 80.1603(c)(1) shall be calculated annually for each 

applicable averaging period according to the following equation:

CRa = Va × (10 − Sa)

Where:

CRa = Credits generated for the averaging period for use in complying with the annual 

average standards of § 80.1603(a).

Va = Total annual volume of gasoline produced at a refinery or imported during the 

averaging period.

Sa = Actual annual average sulfur level, calculated in accordance with the provisions 

of § 80.1603(c)(1), for gasoline produced at a refinery or imported during the averaging 

period, exclusive of any credits. The value of Sa must be less than 10.00.
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(d) For approved small refiners and small volume refineries only, the number of 

credits generated from January 1, 2017 through December 31, 2019 shall be calculated 

annually for each applicable averaging period as follows:

(1) If a small refiner or small volume refinery has an annual average sulfur level (Sa) 

(Sa) less than 30.00 ppm but greater than 10.00 ppm from January 1, 2017 through 

December 31, 2019, the refiner may generate credits using the equation specified in 

paragraph (b) of this section for use in complying with the annual average standards of 

subpart H of this part.

(2) If a small refiner or small volume refinery has an annual average sulfur level (Sa) 

less than 10.00 ppm from January 1, 2017 through December 31, 2019, the refiner may

generate credits using the equation specified in paragraph (c) of this section for use in 

complying with the annual average standards of § 80.1603(c)(1) and the following 

equation for complying with the annual average standards of subpart H of this part:

CRT2 = Va × (20.00)

Where:

CRT2 = Credits generated for the averaging period for use in complying with the annual 

average standards of subpart H of this part only.

Va = Total annual volume of gasoline produced at a refinery or imported during the 

averaging period.

(For example: A small refiner with an annual average sulfur level of 8 ppm in 

2018 may generate CRa = 2 ppm-volume credits (10-8) for compliance with the annual 

average standards of § 80.1603(c)(1) plus CRT2 = 20 ppm-volume credits (30-10) for 

compliance with the annual average sulfur standards of subpart H of this part.).

(3) Beginning January 1, 2020, small refiners and small volume refineries must 

follow paragraph (c) of this section for calculating credits under this subpart O.

(e) No credits shall be generated–

(1) Under paragraphs (b), (c) and (d) of this section unless the value of CRa is 

positive.

(2) Under paragraph (d)(2) of this section unless the value of CRT2 is positive.

(f) The values of CRa and CRT2 shall be rounded to the nearest ppm-gallon in 

accordance with the rounding procedure specified in § 80.9.

(g) A refiner or importer that includes downstream added oxygenates in its RFG or 

conventional gasoline volume under the provisions of §§ 80.69 and 80.101(d)(4), 

respectively and §§ 80.340 and 80.1603(d), shall include the downstream added 

oxygenate for the purpose of generating credits under paragraphs (b) through (d) of this 

section.

§ 80.1616 Credit use and transfer.
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(a) Credit use. (1) Only refiners and importers may generate, use, transfer or own 

credits generated under this subpart O.

(2) CRa credits generated pursuant to subpart H of this part in the 2012 and 2013 

averaging periods and generated pursuant to § 80.1615 may be used by refiners and 

importers to meet the applicable annual average sulfur standards of § 80.1603(a)(1).

(3) CRa credits generated under § 80.1615 may be used to meet the requirements of 

either subpart H of this part or this subpart O, subject to the credit life restrictions in 

paragraph (b) of this section.

(5) Credits generated under § 80.1615(c) may only be used to meet the requirements 

of this subpart O.

(6) CRT2 credits generated under § 80.1615(d) may only be used to meet the 

requirements of subpart H of this part.

(b) Credit life. (1) Except as provided in paragraph (b)(2) of this section, credits are 

valid for use for five years after the year in which they are generated.

(2) Credits generated under § 80.1615(b) through (d) are valid for use for five years 

after the year in which they are generated, except that any CRa credits generated in 2015 

and 2016 and any remaining CRT2 credits will expire and become invalid after March 31, 

2020, when the 2019 annual compliance report is due.

(3) A refiner or importer possessing credits must use all credits prior to falling into a 

compliance deficit.

(4) In no case may a credit be transferred more than twice before being used or 

terminated.

(c) Credit transfers. (1) Credits obtained from other refiners or importers may be 

used to meet the annual average standards of this subpart O, if all the following 

conditions are met:

(i) The credits are generated and reported according to the requirements of this 

subpart O.

(ii) The credits are used in compliance with the limitations regarding the appropriate 

periods for credit use pursuant to paragraph (a) of this section.

(iii) Any credit transfer takes place by March 31 following the calendar year averaging 

period when the credits are used.

(iv) The credit has not been transferred between EPA registered companies more than 

twice. The first transfer by the refiner or importer who generated the credit (“transferor”) 

may only be made to a refiner or importer who intends to use the credit (“transferee”); if 

the transferee cannot use the credit, it may make the second, and final, transfer only to a 

refiner or importer who intends to use the credit. Credit transfers that occur within a 

company are unlimited.

(v) The credit transferor must apply any credits necessary to meet the transferor’s 

applicable average standard before transferring credits to any other refiner or importer.

(vi) The credit transferor does not create a negative credit balance as a result of the 

credit transfer.

(vii) Each transferor must supply to the transferee records indicating all the following:
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(A) The years the credits were generated.

(B) The identity of the refiner or importer who generated the credits.

(C) The identity of the transferring party (if it is not the same party that generated the 

credits).

(2) In the case of credits that have been calculated or created improperly, or are 

otherwise determined to be invalid, all the following provisions apply:

(i) Invalid credits cannot be used to achieve compliance with the transferee’s 

averaging standard, regardless of the transferee’s good faith belief that the credits were 

valid.

(ii) The refiner or importer who used the credits, and any transferor of the credits, 

must adjust their credit records and reports and sulfur calculations as necessary to reflect 

the proper credits.

(iii) Any properly created credits existing in the transferor’s credit balance after 

correcting the credit balance, and after the transferor applies credits as needed to meet the 

average standard at the end of the compliance year, must first be applied to correct the 

invalid transfers before the transferor trades or banks the credits.

(3) CRT2 credits generated under § 80.1615(d) from January 1, 2017 through 

December 31, 2019 may only be traded to and ultimately used from January 1, 2017 

through December 31 by small refiners and small volume refineries approved under § 

80.1622.

§ 80.1620 Small refiner definition.

(a) For the purposes of this subpart O, a gasoline small refiner is defined as any 

refiner who meets all the following criteria and has been approved by EPA as a small 

refiner per § 80.1622:

(1) Produces gasoline at its refineries by processing crude oil through refinery

processing units.

(2) Employed an average of no more than 1,500 people, based on the average number 

of employees for all pay periods for calendar year 2012 for all subsidiary companies, all 

parent companies, all subsidiaries of the parent companies, and all joint venture partners.

(3) Had a corporate-average crude oil capacity less than or equal to 155,000 barrels 

per calendar day (bpcd) for 2012.

(b) For the purposes of this section, the term “refiner” shall include foreign refiners.

(c) The number of employees and crude oil capacity under paragraph (a) of this 

section shall be determined as follows:

(1) The refiner shall include the employees and crude oil capacity of any subsidiary 

companies, any parent company and subsidiaries of the parent company in which the 

parent has 50 percent or greater ownership, and any joint venture partners.

(2) For any refiner owned by a governmental entity, the number of employees and 

total crude oil capacity as specified in paragraph (a) of this section shall include all 
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employees and crude oil production of the government to which the governmental entity

is a part.

(d) Notwithstanding the provisions of paragraphs (a) and (e)(1) of this section, a 

refiner that acquires or reactivates a refinery that was shut down or non-operational 

during calendar year 2011, may apply for small refiner status under this subpart O.

(e) The following are ineligible for small refiner provisions under this subpart O:

(1) Refiners with refineries built or started up on or after January 1, 2012.

(2) Persons who exceed the employee or crude oil capacity criteria under this section 

on January 1, 2012, but who meet these criteria after that date, regardless of whether the 

reduction in employees or crude oil capacity is due to operational changes at the refinery

or a company sale or reorganization.

(3) Importers.

(4) Refiners who produce gasoline other than by processing crude oil through 

refinery processing units.

(f)(1) A refiner approved as a small refiner under § 80.1622 who subsequently ceases 

production of gasoline from processing crude oil through refinery processing units, 

employs more than 1,500 people, or exceeds the 155,000 bpcd crude oil capacity limit 

after January 1, 2012 as a result of merger with or acquisition of or by another entity, is 

disqualified as a small refiner, except as provided for under paragraph (f)(4) of this 

section. If such disqualification occurs, the refiner shall notify EPA in writing no later 

than 20 days following the disqualifying event.

(2) Except as provided under paragraph (f)(3) of this section, any refiner whose status 

changes under this paragraph (f) shall meet the applicable standards of § 80.1603 within a 

period of up to 30 months from the disqualifying event for any of its refineries that were 

previously subject to the small refiner standards of § 80.1623.

(3) A refiner may apply to EPA for up to an additional six months to comply with the 

standards of § 80.1603 if more than 30 months would be required for the necessary

engineering, permitting, construction, and start-up work to be completed. Such 

applications must include detailed technical information supporting the need for 

additional time. EPA will base a decision to approve additional time on information 

provided by the refiner and on other relevant information.

(4) Disqualification under this paragraph (f) of this section shall not apply in the case 

of a merger between two previously approved small refiners.

(5) If a refiner receives a delay per paragraphs (f)(2) and/or (f)(3) of this section, the 

refiner may not generate gasoline sulfur credits under this subpart O during that 30 or 36 

month period.

(6) All written notifications to EPA should be submitted to the address listed in § 

80.1622.

§ 80.1621 Small volume refinery definition.
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(a) For the purposes of this subpart O, a gasoline small volume refinery is defined as 

any refinery that meets all the following criteria, and has been approved by EPA as a 

small volume refinery per § 80.1622:

(1) Produces gasoline by processing crude oil through refinery processing units.

(2) The average aggregate daily crude oil throughput, including feedstocks derived 

from crude oil, for the calendar year 2012 (as determined by dividing the aggregate 

throughput for the calendar year by the number of days in the calendar year) does not 

exceed 75,000 barrels. Throughput means the total crude oil feedstock input into the 

refinery less volumes injected into the crude oil supply after refinery processing.

(b) The following are ineligible for the small volume refinery provisions under this 

subpart O:

(1) Refineries built or started up on or after January 1, 2013.

(2) Persons who exceed the crude oil throughput under this section for calendar year 

2012 but who meet these criteria after that date, regardless of whether the reduction in 

crude oil capacity is due to operational changes at the refinery or a company sale or 

reorganization.

(3) Importers.

(4) Refineries that produce gasoline other than by processing crude oil through 

refinery processing units.

§ 80.1622 Approval for small refiner and small volume refinery status.

(a) Applications for small refiner or small volume refinery status under this subpart O 

must be submitted to EPA by January 1, 2015.

(b) To qualify for small refiner status under this subpart a refiner must submit an 

application to EPA containing all the following information for the refiner and for all 

subsidiary companies, all parent companies, all subsidiaries of the parent companies, and 

all joint venture partners:

(1)(i) A listing of the name and address of all company locations for the period January

1, 2012 through December 31, 2012.

(ii) The average number of employees at each location, based on the number of 

employees for each pay period for the period January 1, 2012 through December 31, 

2012.

(iii) The type of business activities carried out at each location.

(iv) For joint ventures, the total number of employees includes the combined 

employee count of all corporate entities in the venture.

(v) For government-owned refiners, the total employee count includes all government 

employees.

(2)(i) The total corporate crude oil capacity of each refinery as reported to the Energy

Information Administration (EIA) of the U.S. Department of Energy (DOE), for the 
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period January 1, 2012 through December 31, 2012. The information submitted to EIA is 

presumed to be correct. In cases where a company disagrees with this information, the 

company may petition EPA with appropriate data to correct the record when the company 

submits its application.

(ii) Foreign small refiners applying for approval under this section must send the total 

corporate crude oil capacity of each refinery for the period January 1, 2012 through 

December 31, 2012, to the address listed in paragraph (g) of this section.

(3) The application must be signed by the president, chief operating or chief 

executive officer of the company, or his/her designee, stating that the information is true 

to the best of his/her knowledge, and that the company owned the refinery as of 

December 31, 2012.

(4) Name, address, phone number, facsimile number, and e-mail address of a 

corporate contact person.

(c) To qualify for small volume refinery status under this subpart, a refiner must 

submit an application to EPA containing all the following information for the refinery, or 

refineries, for which the refiner is applying for small volume refinery status:

(1) A listing of the name and address of each small volume refinery owned by the 

company.

(2)(i) The total crude throughput of each small volume refinery, defined as the total 

crude oil feedstock input into the refinery less the volumes injected into the crude oil 

supply after refinery processing, as reported to EIA, for the period January 1, 2012 

through December 31, 2012. The information submitted to EIA is presumed to be 

correct. In cases where a company disagrees with this information, the company may

petition EPA with appropriate data to correct the record when the company submits its 

application.

(ii) Foreign refiners applying for small volume refinery approval under this section 

must send the total crude throughput of each small volume refinery, defined as the total 

crude oil feedstock input into the refinery less the volumes injected into the crude oil 

supply after refinery processing of each refinery for the period January 1, 2012 through 

December 31, 2012, to the address listed in paragraph (g) of this section.

(3) The application must be signed by the president, chief operating or chief 

executive officer of the company, or his/her designee, stating that the information is true 

to the best of his/her knowledge, and that the company owned the refinery as of 

December 31, 2012.

(4) Name, address, phone number, facsimile number, and e-mail address of a 

corporate contact person.

(d) For foreign refiners, the small refiner or small volume refinery status application 

must contain all of the elements required in paragraph (b) or (c) of this section, as 

applicable, must demonstrate compliance with § 80.1620, and must be submitted by June 

1, 2016 to the address listed in paragraph (g) of this section.
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(e) A refiner who qualifies as a small refiner or small volume refinery under this 

subpart and subsequently fails to meet all the qualifying criteria as set out in §§ 80.1620 

and 80.1621 will be disqualified pursuant to § 80.1620(f) or § 80.1621(d).

(1) In the event such disqualification occurs, the refiner shall notify EPA in writing 

no later than 20 days following the disqualifying event.

(2) Disqualification under this paragraph (e) shall not apply in the case of a merger 

between two approved small refiners.

(3) Any refiner that acquires a refinery from another refiner with approved small 

refiner or small volume refinery status under this subpart shall notify EPA in writing no 

later than 20 days following the acquisition.

(f) If EPA finds that a refiner provided false or inaccurate information in its small 

refiner status or small volume refinery status application under this subpart, the refiner’s 

small refiner or small volume refinery status will be void as of the effective date of this 

subpart.

(g) Small refiner and small volume refinery status applications, and any other 

correspondence required by this section, § 80.1620, or § 80.1621 shall be sent to the 

following address: U.S. EPA—Attn: Tier 3 Program (Small Refiner/Small Volume 

Refinery Application), 6406J, 1200 Pennsylvania Avenue, NW., Washington, DC 20460.

§§ 80.1623—80.1624 [Reserved]

§ 80.1625 Hardship provisions. 

EPA may, at its discretion, grant a refiner of gasoline that processes crude oil through 

refinery processing units, for one or more of its refineries, temporary relief from some or 

all of the provisions of this subpart.

(a) Extreme hardship circumstances. (1) EPA may, at its discretion, grant a refiner of 

gasoline that processes crude oil through refinery processing units, for one or more of its 

refineries, temporary relief from some or all of the provisions of this subpart. EPA may

grant such relief provided that the refiner demonstrates all the following:

(i) Unusual circumstances exist that impose extreme hardship and significantly affect 

the refiner’s ability to comply by the applicable date.

(ii) It has made best efforts to comply with the requirements of this subpart.

(2) The application must specify the factors that demonstrate a significant economic 

hardship and must provide a detailed discussion regarding the inability of the refinery to 

produce gasoline meeting the requirements of § 80.1603. Such an application must 

include, at a minimum, all the following information:

(i) Documentation of efforts made to obtain necessary financing, including all the 

following:
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(A) Copies of loan applications for the necessary financing of the construction of 

appropriate sulfur reduction technology and other equipment procurements or 

improvements.

(B) If financing has been disapproved or is otherwise unsuccessful, documents 

supporting the basis for that disapproval and evidence of efforts to pursue other means of 

financing.

(ii) A detailed analysis of the reasons the refinery is unable to produce gasoline 

meeting the standards of this subpart O in 2017, including costs, specification of 

equipment still needed, potential equipment suppliers, and efforts already completed to 

obtain the necessary equipment.

(iii) If unavailability of equipment is part of the reason for the inability to comply, a 

discussion of other options considered, and the reasons these other options are not 

feasible.

(iv) If relevant, a demonstration that a needed or lower cost technology is immediately

unavailable, but will be available in the near future, and full information regarding when 

and from what sources it will be available.

(v) Schematic drawings of the refinery configuration as of January 1, 2011, and as of 

the date of the hardship extension application, and any planned future additions or 

changes.

(vi) If relevant, a demonstration that a temporary unavailability exists of engineering 

or construction resources necessary for design or installation of the needed equipment.

(vii) A detailed analysis of the reasons the refinery is unable to use credits to meet the 

gasoline standards of this subpart O, including all avenues pursued to generate and/or 

procure credits, their cost, and ability to finance them.

(viii) A discussion of any sulfur reductions that can be achieved from current levels.

(ix) The date the refiner anticipates compliance with the standards in § 80.1603 can be 

achieved at its refinery.

(x) An analysis of the economic impact of compliance on the refiner’s business 

(including financial statements from the last 5 years, or for any time period up to 10 

years, at EPA’s request).

(xi) Any other information regarding other strategies considered, including strategies 

or components of strategies that do not involve installation of equipment, and why

meeting the standards in § 80.1603 beginning in 2017 (or 2020 for approved small 

refiners and small volume refineries) is infeasible.

(3) Hardship applications under this paragraph (a) must be submitted to EPA by 

January 1, 2016 to the address listed in paragraph (d) of this section.

(b) Extreme unforeseen circumstances hardship. (1) In appropriate extreme, unusual, 

and unforeseen circumstances (for example, natural disaster or refinery fire) which are 

clearly outside the control of the refiner or importer and which could not have been 

avoided by the exercise of prudence, diligence, and due care, EPA may permit a refiner 

or importer, for a brief period, to distribute gasoline which does not meet the 

requirements of this subpart for all the following reasons:
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(i) It is in the public interest to do so (e.g., distribution of the nonconforming 

gasoline is necessary to meet projected shortfalls which cannot otherwise be compensated 

for).

(ii) The refiner or importer exercised prudent planning and was not able to avoid the 

violation and has taken all reasonable steps to minimize the extent of the nonconformity.

(iii) The refiner or importer can show how the requirements for making compliant 

gasoline, and/or purchasing credits to partially or completely offset the nonconformity, 

will be expeditiously achieved.

(iv) The refiner or importer agrees to make up any air quality detriment associated 

with the nonconforming gasoline, where practicable.

(v) The refiner or importer pays to the U.S. Treasury an amount equal to the 

economic benefit of the nonconformity minus the amount expended pursuant to 

paragraph (b)(1)(iv) of this section, in making up the air quality detriment.

(2) The hardship application must meet all other applicable requirements of this 

section, except paragraph (a) of this section.

(c) Applications. (1) The hardship extension application must contain a letter signed 

by the president or the chief operating officer or chief executive officer of the company, 

or his/her designee, stating that the information contained in the application is true to the 

best of his/her knowledge.

(2) Hardship applications under this section must be submitted in writing to the 

following address:

U.S. EPA—Attn: Tier 3 Program (Hardship Application), 6406J, 1200 Pennsylvania 

Avenue, NW., Washington, DC 20460.

§§ 80.1626—80.1629 [Reserved]

§ 80.1630 Sampling and testing requirements for refiners, gasoline importers and 

producers and importers of certified ethanol denaturant. 

(a) Sample and test each batch of gasoline and certified ethanol denaturant. (1) 

Refiners and importers shall collect a representative sample from each batch of gasoline 

produced or imported and test each sample to determine its sulfur content for compliance 

with requirements under this subpart prior to the gasoline leaving the refinery or import 

facility, using the sampling and testing methods provided in this section or §§ 80.8 

(sampling) and 80.47 (testing).

(2) Producers and importers of certified ethanol denaturant shall collect a 

representative sample from each batch of certified ethanol denaturant produced or 

imported and test each sample to determine its sulfur content for compliance with 

requirements under this subpart prior to the certified ethanol denaturant leaving the 

certified ethanol denaturant production or import facility, using the sampling and testing 

methods provided in this section or §§ 80.8 (sampling) and 80.47 (testing).
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(3) Except as provided in paragraph (a)(4) of this section, the requirements of this 

section apply beginning January 1, 2017 for gasoline refiners and importers. For 

producers and importers of certified ethanol denaturants, the requirements of this section 

apply beginning January 1, 2017, or the first date that certified ethanol denaturant is 

introduced into commerce, whichever is earlier. 

(4)(i) Beginning January 1, 2017, any refiner who produces gasoline using computercontrolled in-line blending equipment is exempt from the requirement of paragraph (a)(1) 

of this section to obtain the test results required under paragraph (a)(1) of this section 

prior to the gasoline leaving the refinery, provided that the refiner obtains an exemption 

from this requirement from EPA. To obtain such exemption, the refiner must–

(A) Have been granted an in-line blending exemption under § 80.65(f)(4); or

(B) If the refiner has not been granted an exemption under § 80.65(f)(4), submit to 

EPA all of the information required under § 80.65(f)(4)(i)(A). A letter signed by the 

president, chief operating officer or chief executive officer of the company, or his/her 

designee, stating that the information contained in the submission is true to the best of 

his/her belief must accompany any submission under this paragraph (a)(4)(i)(B).

(ii) Refiners who seek an exemption under paragraph (a)(4)(i) of this section must 

comply with any EPA request for additional information or any other requirements that 

EPA includes as part of the exemption.

(iii) Within 60 days of EPA’s receipt of a submission under paragraph (a)(4)(i)(B) of 

this section, EPA will notify the refiner if the exemption is not approved or of any

deficiencies in the refiner’s submission, or if any additional information is required or 

other requirements are included in the exemption pursuant to paragraph (a)(4)(ii) of this 

section. In the absence of such notification from EPA, the effective date of an exemption 

under paragraph (a)(4)(i) of this section for refiners who do not hold an exemption under 

§ 80.65(f)(4) is 60 days from EPA’s receipt of the refiner’s submission under paragraph 

(a)(4)(i)(B) of this section.

(iv) EPA reserves the right to modify the requirements of an exemption under 

paragraph (a)(4)(i) of this section, in whole or in part, at any time, if EPA determines that 

the refiner’s operation does not effectively or adequately control, monitor or document 

the sulfur content of the refinery’s gasoline production, or if EPA determines that any

other circumstances exist which merit modification of the requirements of an exemption, 

such as advancements in the state of the art for in-line blending measurement which 

allow for additional control or more accurate monitoring or documentation of sulfur 

content. If EPA finds that a refiner provided false or inaccurate information in any

submission required for an exemption under this section, upon notification from EPA, the 

refiner’s exemption will be void ab initio.

(b) Sampling methods. For purposes of paragraph (a) of this section, refiners, 

gasoline importers, and producers and importers of certified ethanol denaturant shall 

sample each batch of gasoline by using one of the methods specified in § 80.8. 

Alternative methods for sampling batches of certified ethanol denaturant may be used as 

approved by the Administrator.
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(c) Test method for measuring sulfur content of gasoline and certified ethanol 

denaturant. (1) For purposes of paragraph (a) of this section, refiners, gasoline importers, 

and producers and importers of certified ethanol denaturant shall use the method provided 

in § 80.47, as applicable, to measure the sulfur content of gasoline or certified ethanol 

denaturant they produce or import.

(2) Sulfur content shall be reported to the nearest ppm.

(3) Alternative methods for the measurement of the sulfur content of certified ethanol 

denaturants may be used as approved by the Administrator.

§ 80.1631 Gasoline, RBOB, and CBOB sample retention requirements. 

(a) Sample retention requirements. Beginning January 1, 2017, or January 1 of the 

first year credits are generated under § 80.1615, whichever is earlier, any refiner or 

importer shall do all the following:

(1) Collect a representative portion of each sample analyzed under § 80.1630, of at 

least 330 milliliters in volume.

(2) Retain sample portions for the most recent 20 samples collected, or for each 

sample collected during the most recent 21 day period, whichever is greater, not to 

exceed 90 days for any given sample.

(3) Comply with the gasoline sample handling and storage procedures under § 

80.1630 for each sample portion retained.

(4) Comply with any request by EPA to–

(i) Provide a retained sample portion to the Administrator’s authorized 

representative; and

(ii) Ship a retained sample portion to EPA, within two working days of the date of the 

request, by an overnight shipping service or comparable means, to the address and 

following procedures specified by EPA, and accompanied with the sulfur test result for 

the sample determined under § 80.1630.

(b) Sample retention requirement for samples subject to independent analysis 

requirements. (1) Any refiner or importer who meets the independent analysis 

requirements under § 80.65(f) for any batch of reformulated gasoline or RBOB will have 

met the requirements of paragraph (a) of this section, provided the independent 

laboratory meets the requirements of paragraph (a) of this section for the gasoline batch; 

except that the retained RBOB sample for purposes of this subpart O must be a sample of 

the RBOB prior to hand blending with oxygenate.

(2) For samples retained by an independent laboratory under this paragraph (b), the 

test results required to be submitted under paragraph (a) of this section shall be the test 

results determined under § 80.65(e).

(c) Sampling compliance certification. Any refiner or importer shall include with 

each annual report filed under § 80.1652, the following statement, which must accurately 
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reflect the facts and must be signed and dated by the same person who signs the annual 

report:

I certify that I have made inquiries that are sufficient to give me knowledge of the 

procedures to collect and store gasoline samples, and I further certify that the procedures 

meet the requirements of the ASTM procedures required under 40 CFR 80.1630.

(d) Requirements for refiners who analyze composited samples. Prior to January 1, 

2017, for purposes of complying with the requirements of this section, refiners who 

analyze composited samples under § 80.1630 must retain portions of the composited 

samples. Portions of samples of each batch comprising the composited samples are not 

required to be retained.

(e) Requirements for RBOB. For purposes of complying with the requirements of 

this section for RBOB, a sample of each RBOB batch produced must be retained.

§ 80.1640 Standards and requirements that apply to refiners producing gasoline by 

blending blendstocks into previously certified gasoline (PCG).

(a) Any refiner who produces gasoline by blending blendstock into PCG, as defined 

at § 80.2(d), must meet the requirements of § 80.1630 to sample and test every batch of 

gasoline as follows:

(1) Exclude the PCG for purposes of demonstrating compliance with the sulfur 

standards of this subpart O.

(2) To accomplish the exclusion required in paragraph (a)(5) of this section, the 

refiner must determine the volume and sulfur content of the PCG used at the refinery and 

the volume of and sulfur content of the gasoline produced at the refinery, and use the 

compliance calculation procedures in paragraphs (a)(3) and (4) of this section.

(3) For each batch of PCG that is used to produce gasoline the refiner must include 

the volume and sulfur content of the PCG as a negative volume and a positive sulfur 

content in the refiner’s compliance calculations in accord with the requirements at § 

80.1603.

(4) For each batch of gasoline produced at the refinery using PCG and blendstock, the 

refiner must determine the volume and sulfur content of the combined product and 

include each batch of combined product for purposes of sulfur compliance in the 

refinery’s compliance calculations at § 80.1603 without regard to the presence of 

previously certified gasoline in the batch.

(5) The refiner must use any PCG that it includes as a negative batch in its 

compliance calculations pursuant to § 80.1603 as a component in gasoline production 

during the annual averaging period in which the PCG was included as a negative batch in

the refiner’s compliance calculations.

(6) The refiner must also comply with § 80.65(i) when producing RBOB or RFG and 

§ 80.101(g)(9) when producing conventional gasoline or CBOB.
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(7) Any negative annual average sulfur value shall be reported as zero and not as a 

negative result.

(b) In the alternative, a refiner may sample and test each batch of blendstock when 

received at the refinery to determine the volume and sulfur content, and treat each 

blendstock receipt as a separate batch for purposes of compliance calculations for the 

annual average sulfur standard and for reporting. This alternative applies only if every

batch of blendstock used at a refinery during an averaging period has a sulfur content that 

is equal to, or less than, the applicable per-gallon cap standard under § 80.1603.

(c) Refiners who blend only butane into PCG may meet the sampling and testing 

requirements of this subpart O for sulfur by using sulfur test results of the butane 

supplier, provided that the requirements of § 80.82 are met.

(d) Refiners who blend only blender grade pentane into PCG may meet the sampling 

and testing requirements of this subpart O for sulfur by using sulfur test results of the 

pentane supplier, provided that the requirements of § 80.85 are met.

§ 80.1641 Alternative sulfur standards and requirements that apply to importers 

who transport gasoline by truck. 

Importers who import gasoline into the United States by truck may comply with the 

following requirements instead of the requirements to sample and test every batch of 

gasoline under § 80.1630, and the annual sulfur average and per-gallon cap standards 

otherwise applicable to importers under § 80.1603:

(a) Alternative standards. The imported gasoline must comply with the following 

standards:

(1) The annual average standard of 10 ppm and the per-gallon standard of 80 ppm as 

provided by § 80.1603; or

(2) A per-gallon standard of 10 ppm. 

(b) Terminal testing. The importer may use test results for sulfur content testing 

conducted by the terminal operator, for gasoline contained in the storage tank from which 

trucks used to transport gasoline into the United States are loaded, for purposes of 

demonstrating compliance with the standards in paragraph (a) of this section, provided all 

the following conditions are met:

(1) The sampling and testing shall be performed after each receipt of gasoline into the 

storage tank, or immediately before each transfer of gasoline to the importer’s truck.

(2) The sampling and testing shall be performed using the methods specified in §§ 

80.8 and 80.47, respectively.

(3) At the time of each transfer of gasoline to the importer’s truck for import to the 

United States, the importer must obtain a copy of the terminal test result that indicates the 
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sulfur content of the truck load (or each compartment if fuel was loaded from different 

storage tanks).

(c) Quality assurance program. The importer must conduct a quality assurance 

program for each truck loading terminal as follows:

(1) Quality assurance samples must be obtained from the truck-loading terminal and 

tested by the importer, or by an independent laboratory, and the terminal operator must 

not know in advance when samples are to be collected.

(2) The sampling and testing must be performed using the methods specified in §§ 

80.8 and 80.47, respectively.

(3) The quality assurance test results for sulfur must differ from the terminal test 

result by no more than the ASTM reproducibility of the terminal’s test results, as 

determined by the following equation:

R = 105 × ((S +2)/104) 0.4

Where:

R = ASTM reproducibility.

S = Sulfur content based on the terminal’s test result.

(4) The frequency of the quality assurance sampling and testing must be at least one 

sample for each fifty of an importer’s trucks that are loaded at a terminal, or one sample 

per month, whichever is more frequent.

(d) Party required to conduct quality assurance testing. The quality assurance 

program under paragraph (c) of this section shall be conducted by the importer. In the 

alternative, this testing may be conducted by an independent laboratory that meets the 

criteria under § 80.65(f)(2)(iii), provided the importer receives, no later than 21 days after 

the sample was taken, copies of all results of tests conducted.

(e) Assignment of batch numbers. The importer must treat each truckload of 

imported gasoline as a separate batch for purposes of reporting under § 80.1652 and 

assigning batch numbers and maintaining records under § 80.1653.

(f) EPA inspections of terminals. EPA inspectors or auditors, and auditors 

conducting attest engagements under § 80.1667, must be given full and immediate access 

to the truck-loading terminal and any laboratory at which samples of gasoline collected at 

the terminal are analyzed, and must be allowed to conduct inspections, review records, 

collect gasoline samples, and perform audits. These inspections or audits may be either 

announced or unannounced.

(g) Certified Sulfur-FRGAS. This section does not apply to Certified Sulfur-FRGAS.

(h) Reporting requirements. Any importer who elects to comply with the alternative 

standards in paragraph (a) of this section shall comply with all the following 

requirements:
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(1) All importer recordkeeping and reporting requirements under §§ 80.1652 and 

80.1653, except as provided in paragraph (h)(2) of this section.

(2) An importer who elects to comply with the alternative standards in paragraph 

(a)(2) of this section must certify in the annual report whether it is in compliance with the 

applicable per-gallon batch standard set forth in paragraph (a)(2) of this section, in lieu of 

providing the information required by § 80.1652 regarding annual average sulfur content 

and compliance with the average standard under § 80.1603.

(i) Effect of noncompliance. If any of the requirements of this section are not met, 

all gasoline imported by the truck importer during the time any requirements are not met 

is deemed in violation of the gasoline sulfur average and per-gallon cap standards in § 

80.1603. Additionally, if any requirement is not met, EPA may notify the importer of the 

violation and, if the requirement is not fulfilled within 10 days of notification, the truck 

importer may not in the future use the sampling and testing provisions in this section in 

lieu of the provisions in § 80.1630.

§ 80.1642 Sampling and testing requirements for producers and importers of 

denatured fuel ethanol and other oxygenates for use by oxygenate blenders.

Beginning January 1, 2017, producers and importers of denatured fuel ethanol (DFE) and 

other oxygenates for use by oxygenate blenders must satisfy the sampling and testing 

requirements in this section prior to the addition of the oxygenate to gasoline or 

blendstocks for oxygenate blending . 

(a) Sampling requirements. Producers and importers of oxygenates for use by

oxygenate blenders shall collect a representative sample from each batch of oxygenate 

produced or imported prior to the oxygenate leaving the oxygenate production or import 

facility, using the sampling methods specified in § 80.8 or § 80.47.

(b) Determination of oxygenate sulfur content. Producers and importers of 

oxygenates must test each batch of oxygenate they produce or import to determine its 

sulfur content to the nearest ppm using a test method provided in § 80.47, or, with respect 

to DFE may use the alternative means of determining the sulfur content contained in 

paragraph (c) of this section

(c) Alternative means of determining the sulfur content of DFE. As an alternative to 

testing each batch of DFE pursuant to the requirements of paragraph (b) of this section, 

the sulfur content of batches of DFE produced using certified denaturant meeting the 

requirements of § 80.1611 may be determined as follows:

(1) The sulfur content of the batch of DFE shall be calculated by volume weighting 

the sulfur contribution from the denaturant), and the neat ethanol used.

(2) The sulfur content of the neat (un-denatured) ethanol used in the calculation in 

paragraph (c)(1) of this section may be assumed to be negligible or assumed to be some 

specific value for the purposes of calculating the sulfur content of the DFE batch 
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provided that the DFE manufacturer or importer conducts production quality control 

which demonstrates that such an assumption is valid. Otherwise, the sulfur content of the 

neat ethanol must be determined in accordance with the test requirements of § 80.1630.

(3) The sulfur content of the certified denaturant(s) used in the calculation in 

paragraph (c)(1) of this section must be consistent with the PTD(s) obtained from a 

registered certified ethanol denaturant producer(s) or importer(s) in accordance with the 

requirements of § 80.1611. If the PTD from the certified ethanol denaturant states that 

the sulfur content is 330 ppm, then the sulfur content of the sulfur content of the ethanol 

denaturant must be assumed to be 330 ppm.

(4) A sample of each batch of DFE must be retained pursuant to the requirements of § 

80.1643.

(5) The sulfur content of each batch of DFE shall be reported to the nearest ppm.

§ 80.1643 Sample retention requirements for oxygenate producers and 

importers.

(a) Sample retention requirements. Beginning January 1, 2017, any producer or 

importer of oxygenate shall do all the following:

(1) Retain a representative portion of each sample analyzed under § 80.1642(b), of at 

least 330 milliliters in volume.

(2) Retain a representative sample of each batch of DFE for which the DEF producer 

or importer used the alternative means of determining the sulfur contents of the DFE 

batch pursuant to the requirements of § 80.1642(c) , of at least 330 milliliters in volume.

(3) Retain sample portions for the most recent 20 samples collected, or for each 

sample collected during the most recent 21 day period, whichever is greater, not to 

exceed 90 days for any given sample.

(4) Comply with the DFE sample handling and storage procedures under § 80.1642 

for each sample portion retained.

(5) Comply with any request by EPA to–

(i) Provide a retained sample portion to the Administrator’s authorized 

representative; and

(ii) Ship a retained sample portion to EPA, within two working days of the date of the 

request, by an overnight shipping service or comparable means, to the address and 

following procedures specified by EPA, and accompanied with the sulfur test result for 

the sample determined under § 80.1642 or the calculated sulfur content of the of the batch 

from which the sample was drawn determined pursuant to the requirements of § 

80.1611(e).

(b) [Reserved]
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§ 80.1644 Sampling and testing requirements for producers and importers of 

certified ethanol denaturant.

(a) Sample and test each batch of certified ethanol denaturant. (1) Producers and 

importers of certified ethanol denaturant shall collect a representative sample from each 

batch of certified ethanol denaturant produced or imported and test each sample to 

determine its sulfur content for compliance with requirements under this subpart prior to 

the ethanol denaturant leaving the production or import facility, using the sampling and 

testing methods provided in this section or §§ 80.8 (sampling) and 80.47 (testing).

(2) The requirements of this section apply beginning January 1, 2017 or on the first 

day that an ethanol denaturant manufacturer designates a batch of ethanol denaturant as 

compliant with the requirements of § 80.1611, whichever is earlier.

(b) Determination of certified ethanol denaturant sulfur content. Producers and 

importers of certified ethanol denaturant who are required to test each batch of certified 

ethanol denaturant they produce or import to determine its sulfur content pursuant to the 

requirements of § 80.1611 shall use the testing methods specified in paragraph (c) of this 

section.

(c) Test method for measuring sulfur content of certified ethanol denaturant. (1) For 

purposes of paragraph (b) of this section, producers and importers of certified ethanol 

denaturant shall use the method provided in § 80.47 to measure the sulfur content of 

certified ethanol denaturant they produce or import. Alternative test methods may be 

used as approved by the Administrator. 

(2) The sulfur content of each batch of ethanol denaturant shall be reported to the 

nearest ppm.

§ 80.1645 Sample retention requirements for producers and importers of 

denaturant designated as suitable for the manufacture of denatured fuel ethanol 

meeting federal quality requirements.

Beginning January 1, 2017, or on the first day that any producer or importer of ethanol 

denaturant designates a batch of ethanol denaturant as suitable for the manufacture of 

denatured fuel ethanol meeting federal quality requirements, whichever is earlier, the 

ethanol denaturant producer or importer shall do all the following:

(a) Retain a representative portion of each sample collected under § 80.1644, of at 

least 330 milliliters in volume.

(b) Retain sample portions for the most recent 20 samples collected, or for each 

sample collected during the most recent 21 day period, whichever is greater, not to 

exceed 90 days for any given sample.

(c) Comply with the ethanol denaturant sample handling and storage procedures 

under § 80.1644 for each sample portion retained.

(d) Comply with any request by EPA to–
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(1) Provide a retained sample portion to the Administrator’s authorized 

representative; and

(2) Ship a retained sample portion to EPA, within two working days of the date of the 

request, by an overnight shipping service or comparable means, to the address and 

following procedures specified by EPA, and accompanied with the sulfur test result for 

the sample determined under § 80.1644.

§§ 80.1646-80.1649 [Reserved]

§ 80.1650 Registration. 

The following registration requirements apply under this subpart:

(a) Registration. Registration with the EPA Administrator is required for any–

(1) Gasoline refiner or importer having any refinery or import facility subject to the 

gasoline sulfur standards under this subpart O, unless already registered as a gasoline 

refiner or importer under § 80.76 or § 80.103.

(2) Oxygenate producer or importer having any oxygenate production facility or 

import facility subject to the oxygenate sulfur standards under § 80.1610.

(3) Oxygenate blender who has any oxygenate blending facility that blends oxygenate 

into gasoline, RBOB, or CBOB where the resulting gasoline is subject to the gasoline 

sulfur standards under this subpart O, unless already registered as an oxygenate blender 

under § 80.76.

(4) Producer or importer of certified.

(b) Registration dates. (1) Any gasoline refiner or importer required to register shall 

do so by December 1, 2016, or at least 30 days in advance of the first date that such 

person will produce or import reformulated gasoline, conventional gasoline, RBOB, or 

CBOB, whichever is earlier. If a previously unregistered refiner or importer intends to 

generate credits prior to January 1, 2017 (pursuant to § 80.1615), registration must occur 

at least 90 days prior to submitting an annual compliance report demonstrating credit 

generation.

(2) Any oxygenate producer or importer required to register shall do so by November 

1, 2016, or at least 60 days in advance of the first date that such person will produce or 

import oxygenate, whichever is earlier.

(3) Any oxygenate blender required to register shall do so by November 1, 2016, or at 

least 90 days in advance of the first date that such person will blend oxygenate into 

RBOB, whichever is earlier.

(4) Any ethanol denaturant producer or importer required to register shall do so by

November 1, 2016, or at least 60 days in advance of the first date that such person will 

produce or import ethanol denaturant, whichever is earlier. 
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(c) Refiner registration. (1) Registration shall be on forms and use procedures 

prescribed by the Administrator, and shall include all the following information:

(i) The name, business address, contact name, e-mail address, and telephone number 

of the refiner.

(ii) For each separate refinery, the facility name, physical location, contact name, email address, telephone number, and type of facility.

(iii) For each separate refinery–

(A) Whether records are kept on-site or off-site of the refinery.

(B) If records are kept off-site, the primary off-site storage facility name, physical 

location, contact name, e-mail address, and telephone number.

(iv) For each separate refinery that produces reformulated gasoline and/or RBOB, the 

name, address, contact name, e-mail address, and telephone number of the independent 

laboratory used to meet the independent analysis requirements of § 80.65(f).

(2) EPA will supply a company registration number to each refiner, and a facility

registration number for each refinery that is identified. These registration numbers shall 

be used in all reports to the Administrator.

(3)(i)Any refiner shall submit updated registration information to the Administrator 

within thirty days of any occasion when the registration information previously supplied 

becomes incomplete or inaccurate; except that

(ii) EPA must be notified in writing of any change in designated independent 

laboratory under paragraph (a)(1)(iv) of this section at least thirty days in advance of such 

change.

(d) Gasoline importer registration. (1) Registration shall be on forms and use 

procedures prescribed by the Administrator, and shall include all the following 

information:

(i) The name, business address, contact name, e-mail address, and telephone number 

of the importer.

(ii) For each importer’s operations in a single PADD:

(A) Whether records are kept on-site at the registered address or off-site.

(B) If records are kept off-site, the primary off-site storage facility name, physical 

location, contact name, e-mail address, and telephone number.

(C) For importers that import reformulated gasoline and/or RBOB, the name, address, 

contact name and telephone number of the independent laboratory used to meet the 

independent analysis requirements of § 80.65(f).

(2) EPA will supply a company registration number to each importer. This 

registration number shall be used in all reports to the Administrator.

(3)(i)Any importer shall submit updated registration information to the Administrator 

within thirty days of any occasion when the registration information previously supplied 

becomes incomplete or inaccurate; except that

(ii) EPA must be notified in writing of any change in designated independent 

laboratory under paragraph (d)(1)(ii)(C) of this section at least thirty days in advance of 

such change.
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(e) Oxygenate producer registration. (1) Registration shall be on forms and use 

procedures prescribed by the Administrator, and shall include all the following 

information:

(i) The name, business address, contact name, e-mail address, and telephone number 

of the oxygenate producer.

(ii) For each separate oxygenate production facility, the facility name, physical 

location, contact name, telephone number, and type of facility.

(iii) For each separate oxygenate production facility–

(A) Whether records are kept on-site or off-site of the refinery.

(B) If records are kept off-site, the primary off-site storage facility name, physical 

location, contact name, and telephone number.

(iv) The type and chemical composition of the oxygenate.

(2) EPA will supply a company registration number to each oxygenate producer, and 

a facility registration number for each oxygenate production facility that is identified. 

These registration numbers or those provided under § 80.1450 shall be used in all reports 

to the Administrator.

(3) Any oxygenate producer shall submit updated registration information to the 

Administrator within thirty days of any occasion when the registration information 

previously supplied becomes incomplete or inaccurate.

(f) Oxygenate importer registration. (1) Registration shall be on forms and use 

procedures prescribed by the Administrator, and shall include all the following 

information:

(i) The name, business address, contact name, and e-mail address, telephone number 

of the importer.

(ii) For each importer’s operations in a single PADD–

(A) Whether records are kept on-site at the registered address or off-site.

(B) If records are kept off-site, the primary off-site storage facility name, physical 

location, contact name, e-mail address, and telephone number.

(iii) The type and chemical composition of the oxygenate.

(2) EPA will supply a company registration number to each importer. This 

registration number shall be used in all reports to the Administrator.

(g) Oxygenate blender registration. (1) Registration shall be on forms and use 

procedures prescribed by the Administrator, and shall include all the following 

information:

(i) The name, business address, contact name, and e-mail address, telephone number 

of the oxygenate blender.

(ii) For each separate oxygenate blending facility, the facility name, physical location, 

contact name, telephone number, and type of facility.

(iii) For each separate oxygenate blending facility–

(A) Whether records are kept on-site or off-site of the refinery.
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(B) If records are kept off-site, the primary off-site storage facility name, physical 

location, contact name, e-mail address, and telephone number.

(iv) The type and chemical composition of the oxygenate.

(2) EPA will supply a company registration number to each oxygenate blender, and a 

facility registration number for each oxygenate blending facility that is identified. These 

registration numbers or those provided under § 80.1450 shall be used in all reports to the 

Administrator.

(3) Any oxygenate producer shall submit updated registration information to the 

Administrator within thirty days of any occasion when the registration information 

previously supplied becomes incomplete or inaccurate.

(h) Certified ethanol denaturant producer registration. (1) Registration shall be on 

forms and use procedures prescribed by the Administrator, and shall include all the 

following information:

(i) The name, business address, contact name, e-mail address, and telephone number 

of the ethanol denaturant producer.

(ii) For each separate ethanol denaturant production facility, the facility name, 

physical location, contact name, telephone number, and type of facility.

(iii) For each separate ethanol denaturant production facility–

(A) Whether records are kept on-site or off-site of the ethanol denaturant production 

facility.

(B) If records are kept off-site, the primary off-site storage facility name, physical 

location, contact name, and telephone number.

(2) EPA will supply a company registration number to each ethanol denaturant 

producer, and a facility registration number for each ethanol denaturant production 

facility that is identified. These registration numbers or those provided under § 80.1450 

shall be used in all reports to the Administrator.

(3) Any ethanol denaturant producer shall submit updated registration information to 

the Administrator within thirty days of any occasion when the registration information 

previously supplied becomes incomplete or inaccurate.

(i) Ethanol denaturant importer registration. (1) Registration shall be on forms and 

use procedures prescribed by the Administrator, and shall include all the following 

information:

(i) The name, business address, contact name, and e-mail address, telephone number 

of the importer.

(ii) For each importer’s operations in a single PADD–

(A) Whether records are kept on-site at the registered address or off-site.

(B) If records are kept off-site, the primary off-site storage facility name, physical 

location, contact name, e-mail address, and telephone number.

(2) EPA will supply a company registration number to each importer. This 

registration number shall be used in all reports to the Administrator.
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§ 80.1651 Product transfer document requirements.

(a) Gasoline, RBOB, CBOB, and oxygenates. In addition to any other product 

transfer document requirements under this part 80, on each occasion that any person 

transfers custody or title to any gasoline, RBOB, CBOB, or oxygenate other than when 

gasoline is sold or dispensed for use in motor vehicles at a retail outlet or wholesale 

purchaser-consumer facility, the transferor shall provide to the transferee documents 

which include all the following information:

(1) The name and address of the transferor.

(2) The name and address of the transferee.

(3) The volume of gasoline, RBOB, CBOB, or oxygenate which is being transferred.

(4) The location of the gasoline, RBOB, CBOB, or oxygenate at the time of the 

transfer.

(5) The date of the transfer.

(b) Gasoline for export or with an exemption and California gasoline. In addition to 

any other product transfer document requirements under this part 80, on each occasion 

when any person transfers custody or title to any gasoline for export or with an 

exemption under §§ 80.1654, 80.1655, 80.1656, or 80.1658, any of the following 

statements must be included on the product transfer document:

(1) For gasoline with a national security exemption under § 80.1655, “This gasoline 

is for use in vehicles, engines, or equipment under an EPA-approved national security 

exemption only.”

(2) For gasoline with a research, development, or testing exemption under § 80.1656, 

“This gasoline is for research, development, or testing purposes only.”

(3) For gasoline for use in American Samoa, Guam, and the Commonwealth of the 

Northern Mariana Islands under § 80.1658, “This is gasoline for use only in Guam, 

American Samoa, or the Northern Mariana Islands.”

(4) For gasoline for export purposes, “This gasoline is for export only.”

(5) For gasoline for racing purposes, “This gasoline is for racing purposes only.”

(6) For California gasoline, pursuant to § 80.1654, “California gasoline”.

(c) Gasoline additive. On each occasion when any person transfers custody or title to 

any gasoline additive intended to be used at less than 1 volume percent, other than when 

the gasoline additive is sold or dispensed for use in motor vehicles at a retail outlet or 

wholesale purchaser-consumer facility, the transferor shall provide to the transferee 

documents which include information on the maximum recommended treatment level. 

(d) Ethanol denaturant. On each occasion when any person transfers custody or title 

to any ethanol denaturant designated as suitable for use in the manufacture of denatured 

fuel ethanol meeting federal quality requirements pursuant to § 80.1611, the transferor 

shall provide to the transferee documents which include all the following information:

(1) The name and address of the transferor.

(2) The name and address of the transferee.
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(3) The volume of ethanol denaturant which is being transferred.

(4) The location of the ethanol denaturant at the time of the transfer.

(5) The date of the transfer.

(6) A statement identifying the batch as “Ethanol denaturant suitable for the 

manufacture of denatured fuel ethanol meeting federal quality requirements”, or anther 

identifying statement as approved by EPA consistent with the requirements of § 80.1611.

(7) Information on the sulfur content of the ethanol denaturant, as applicable, 

pursuant to the requirements of § 80.1611.

(e) Oxygenate. On each occasion when any person transfers custody or title to any

oxygenate, the transferor shall provide to the transferee documents which include all the 

following information:

(1) The name and address of the transferor.

(2) The name and address of the transferee.

(3) The volume of oxygenate which is being transferred.

(4) The location of the oxygenate at the time of the transfer.

(5) The date of the transfer.

(6) For denatured fuel ethanol, a statement identifying the batch as “Denatured fuel 

ethanol, maximum 10 ppm sulfur”.

(7) For oxygenates other than DFE, the name of the specific oxygenate must be 

identified on the PTD, followed by “maximum 10 ppm sulfur”..

(8) Alternative PTD language to that specified in paragraphs (e)(6) and (7) of this 

section may be used as approved by EPA consistent with the requirements of § 80.1610.

§ 80.1652 Reporting requirements for gasoline refiners, gasoline importers, 

oxygenate producers, and oxygenate importers. 

Beginning with the 2017 averaging period or the first year credits are generated under § 

80.1615 (whichever is earlier), and continuing for each averaging period thereafter, any

gasoline refiner or importer shall submit to EPA annual reports that contain the 

information required in this section, and any other information as EPA may require. 

Beginning with the 2017 calendar year and continuing each calendar year thereafter, any 

oxygenate producer or importer shall submit to EPA annual reports that contain the 

information required in this section, and any other information as EPA may require. 

Reporting shall be on forms and use procedures prescribed by the Administrator. 

(a) Gasoline refiner and importer annual reports. Any refiner, for each of its 

refineries, and any importer for the gasoline it imports, shall submit a report for each 

calendar year averaging period that includes all the following information:

(1) The EPA importer, or refiner and refinery facility registration numbers.

(2) The average standard under § 80.1603, reported to two decimal places.

(3) The total volume of gasoline produced or imported, reported to the nearest whole 

number.
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(4) The annual average sulfur level of the gasoline produced or imported, reported to 

two decimal places.

(5) The annual average sulfur level after inclusion of any credits, reported to two 

decimal places.

(6) Separately provided information for credits, and separately by year of creation, as 

follows:

(i) The number of credits at the beginning of the averaging period, reported to the 

nearest whole number.

(ii) The number of credits generated, reported to the nearest whole number.

(iii) The number of credits used, reported to the nearest whole number.

(iv) If any credits were obtained from or transferred to other parties; and for each 

other party, its name and EPA refiner or importer registration number, and the number of 

credits obtained from or transferred to the other party.

(v) The number of credits that expired at the end of the averaging period, reported to 

the nearest whole number.

(vi) The number of credits that will carry over into the subsequent averaging period, 

reported to the nearest whole number.

(7) For each batch of gasoline produced or imported during the averaging period, all 

the following:

(i) The batch number assigned under § 80.65(d)(3); except that if composite samples 

of conventional gasoline representing multiple batches produced subsequent to December 

31, 2003, are tested under § 80.101(i)(2) for anti-dumping compliance purposes, for 

purposes of this subpart a separate batch number must be assigned to each batch using the 

batch numbering procedures under § 80.65(d)(3).

(ii) The date the batch was produced.

(iii) The volume of the batch, reported to the nearest whole number.

(iv) The sulfur content of the batch, reported to two decimal places, along with 

identification of the test method used to determine the sulfur content of the batch, as 

determined under § 80.1630.

(8) All values measured or calculated pursuant to the requirements of this paragraph 

(a) shall be in accordance with the rounding procedure specified in § 80.9.

(9) When submitting reports under this paragraph (a) from January 1, 2017 through 

December 31, 2019, any importer shall exclude Certified Sulfur-FRGAS.

(b) Additional reporting requirements for gasoline importers. From January 1, 2017 

through December 31, 2019, importers shall report all the following information for 

Sulfur-FRGAS imported during an annual averaging period:

(1) The EPA refiner and refinery registration numbers of each foreign refiner and 

refinery where the Certified Sulfur-FRGAS was produced.

(2) The total gallons of Certified Sulfur-FRGAS and Non-Certified Sulfur-FRGAS 

imported from each foreign refiner and refinery, reported to one decimal place.
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(c) Oxygenate refiner and importer annual reports. Any oxygenate producer, for each 

of its production facilities, and any importer for the oxygenate it imports, shall submit a 

report for each calendar year period that includes all the following information:

(1) The EPA oxygenate importer, or producer and producer facility registration 

numbers.

(2) The total volume of oxygenate produced or imported, reported to the nearest 

whole number.

(3) For each batch of oxygenate produced or imported during the calendar year, all 

the following:

(i) The batch number assigned under § 80.1610(d).

(ii) The date the batch was produced.

(iii) The volume of the batch, reported to the nearest whole number.

(iv) The sulfur content of the batch, reported to two decimal places.

(v) For oxygenates other than denatured fuel ethanol, the identification of the test 

method used to determine the sulfur content of the batch pursuant to the requirements of 

§ 80.1642(c).

(vi) For denatured fuel ethanol, either the identification of the test method used to 

determine the sulfur content of the batch (pursuant to § 80.1642), or the information used

to calculate the sulfur content pursuant to the requirements of § 80.1642(c).

(4) All values measured or calculated pursuant to the requirements of this paragraph 

(c) shall be in accordance with the rounding procedure specified in § 80.9.

(d) Report submission. Any annual report required under this section shall be–

(1) Signed and certified as meeting all of the applicable requirements of this subpart 

by the owner or a responsible corporate officer of the refiner, gasoline importer, 

oxygenate producer, oxygenate importer, denaturant producer, or denaturant importer; 

and

(2) Submitted to EPA no later than the March 31 each year for the prior calendar 

year.

(e) Attest reports. Attest reports for refiner and importer attest engagements required 

under § 80.1667 shall be submitted to the Administrator by June 1 of each year for the 

prior calendar year.

§ 80.1653 Recordkeeping. 

Unless otherwise provided for in this section, the records required by this section shall be 

retained for a period of five years from the date of creation, and shall be delivered to the 

Administrator of EPA or to the Administrator's authorized representative upon request.

(a) Records that must be kept by gasoline refiners, importers, and parties in the 

gasoline distribution system. Beginning January 1, 2017 or January 1 of the first year 

that credits are generated (whichever is earlier), any person who produces, imports, sells, 
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offers for sale, dispenses, distributes, supplies, offers for supply, stores, or transports 

gasoline, shall keep records containing the information as required in this section. 

(1) The product transfer document information required under § 80.1651.

(2) All the following information for any sampling and testing for sulfur content 

required under this subpart O:

(i) The location, date, time, and storage tank or truck identification for each sample 

collected.

(ii) The name and title of the person who collected the sample and the person who 

performed the test.

(iii) The results of the test as originally printed by the testing apparatus, or where no 

printed result is produced, the results as originally recorded by the person who performed 

the test.

(iv) Any record that contains a test result for the sample that is not identical to the 

result recorded under paragraph (a)(2)(iii) of this section.

(v) The test methodology used.

(b) Additional records that refiners and importers must keep. Beginning January 1, 

2014, or January 1 of the first year credits are generated under § 80.1615, whichever is 

earlier, any refiner for each of its refineries and any importer for the gasoline it imports, 

shall keep records that include all the following information:

(1) For each batch of gasoline produced or imported–

(i) The batch volume.

(ii) The batch number assigned under § 80.65(d)(3) and the appropriate designation 

under paragraph (b)(1)(iv) of this section; except that for composite samples of 

conventional gasoline representing multiple batches , that are tested under § 80.101(i)(2) 

for purposes of this subpart, a separate batch number must be assigned to each batch 

using the batch numbering procedures under § 80.65(d)(3).

(iii) The date of production or importation.

(iv) If appropriate, the designation of the batch as California gasoline under § 

80.1654, exempt gasoline for national security purposes under § 80.1655, exempt 

gasoline for research and development under § 80.1656, or for export outside the United 

States.

(v) The test methodology used.

(2) Information regarding credits, separately kept according to the year of creation; 

and for credit generation or use starting in 2014. The following information shall be kept 

separately for each type of credit generated under § 80.1615:

(i) The number of credits in the refiner’s or importer’s possession at the beginning of 

the averaging period.

(ii) The number of credits generated.

(iii) The number of credits used.

(iv) If any credits were obtained from or transferred to other parties, all the following 

for each other party:

(A) The party’s name.
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(B) The party’s EPA refiner or importer registration number.

(C) The number of credits obtained from, or transferred to, the party.

(v) The number of credits that expired at the end of the averaging period.

(vi) The number of credits in the refiner’s or importer’s possession that will carry over 

into the subsequent averaging period.

(vii) Contracts or other commercial documents that establish each transfer of credits 

from the transferor to the transferee.

(3) The calculations used to determine compliance with the applicable sulfur average 

standards of § 80.1603 or § 80.1604.

(4) The calculations used to determine the number of credits generated under § 

80.1615.

(5) A copy of all reports submitted to EPA under § 80.1652.

(6) In the case of parties who process transmix, records of any sampling and testing 

required under § 80.1607.

(c) Additional records gasoline importers must keep. Any importer shall keep 

records that identify and verify the source of each batch of certified Sulfur-FRGAS and 

non-certified Sulfur-FRGAS imported and demonstrate compliance with the requirements 

for importers under § 80.1666.

(d) Records that producers and importers of denatured fuel ethanol and other 

oxygenates must keep. Beginning January 1, 2017 or the first date when DFE is 

introduced into commerce that is represented on the product transfer document as 

meeting the standards in § 80.1610 (whichever is earlier), records of all the following 

must be kept for each batch of oxygenate produced or imported by oxygenate producers 

and importers:

(1) The date the batch was produced.

(2) The batch number.

(3) The batch volume.

(4) The product transfer document for the batch.

(5) The sulfur content of the batch as determined pursuant to the requirements of § 

80.1642.

(6) The following records shall be kept if the sulfur content of the batch was 

determined by analytical testing:

(i) The location, date, time, and storage tank or truck identification for each sample 

collected

(ii) The name and title of the person who collected the sample and the person who 

performed the test.

(iii) The results of the test as originally printed by the testing apparatus, or where no 

printed result is produced, the results as originally recorded by the person who performed 

the test.

(iv) Any record that contains a test result for the sample that is not identical to the 

result recorded under paragraph (d)(5)(iii) of this section.

(v) The test methodology used.
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(7) For denatured fuel ethanol, the following records shall be kept if the sulfur 

content of the batch was determined by the alternative means of demonstrating 

compliance with the sulfur requirements pursuant to the requirements of § 80.1642(c):

(i) The name and title of the person who calculated the sulfur content of the batch.

(ii) The date the calculation was performed.

(iii) The calculated sulfur content.

(iv) The sulfur content of the neat (un-denatured) ethanol. 

(v) The date each batch of neat ethanol was produced.

(vi) The neat ethanol batch number.

(vii) The neat ethanol batch volume.

(viii) As applicable, the neat ethanol production quality control records, or the test 

results on the neat ethanol including–

(A) The location, date, time, and storage tank or truck identification for each sample 

collected.

(B) The name and title of the person who collected the sample and the person who 

performed the test.

(C) The results of the test as originally printed by the testing apparatus, or where no 

printed result is produced, the results as originally recorded by the person who performed 

the test.

(D) Any record that contains a test result for the sample that is not identical to the 

result recorded under paragraph (d)(7)(v) of this section.

(E) The test methodology used.

(v) The sulfur content of the denaturant(s) used, and the volume percent at which the 

denaturant(s) were added to neat (un-denatured) ethanol to produce denatured fuel 

ethanol.

(vi) The product transfer documents for the denaturants used. 

(e) Records that parties who take custody of oxygenates in the oxygenate distribution 

system must keep. Beginning January 1, 2017 or the first date when a party takes 

custody of oxygenate that is represented on the product transfer document as meeting the 

standards in § 80.1610 (whichever is earlier), all parties that take custody of oxygenate –

from the oxygenate producer through to the oxygenate blender – must keep a copy of the 

product transfer document for each batch of oxygenate.

(f) Records that must be kept by producers and importers of ethanol denaturant 

designated as suitable for use in the manufacturer of denatured fuel ethanol meeting 

federal quality requirements. Beginning January 1, 2017 or the first date when a 

producer or importer of ethanol denaturant designated as suitable for use in the 

manufacturer of denatured fuel ethanol meeting federal quality requirements pursuant to 

the requirements of § 80.1611 introduces such denaturant into commerce, records of all 

the following must be kept for each batch of such denaturant produced or imported:

(1) The date each batch was produced.

(2) The batch number.
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(3) The batch volume.

(4) The product transfer document for the batch.

(5) The sulfur content of the batch.

(6) The location, date, time, and storage tank or truck identification for each sample 

collected.

(7) The name and title of the person who collected the sample and the person who 

performed the test.

(8) The results of the test as originally printed by the testing apparatus, or where no 

printed result is produced, the results as originally recorded by the person who performed 

the test.

(9) Any record that contains a test result for the sample that is not identical to the 

result recorded under paragraph (f)(5) of this section.

(10) The test methodology used.

(g) Records that parties who take custody of ethanol denaturants designated as 

suitable for use in the manufacturer of denatured fuel ethanol meeting federal quality

requirements. Beginning January 1, 2017, all parties that take custody of denaturants 

designated as suitable for use in the manufacture of DFE pursuant to § 80.1611 must 

keep the following records:

(1) The product transfer document for the denaturant.

(2) As applicable, the volume percent at which the denaturant was added to neat 

ethanol.

(h) Records that producers and importers of gasoline additives as defined in 40 CFR 

79.2(f) must keep. Beginning January 1, 2017 producers and importers of gasoline 

additives must keep the following records:

(1) The date the batch was produced.

(2) The volume of the batch.

(3) The product transfer document for the batch.

(4) The maximum recommended treatment rate.

(5) Records of the additive manufacturer’s control practices which demonstrate that 

the additive will contribute no more than 3 ppm on a per gallon basis to the sulfur content 

of gasoline when used at the maximum recommended treatment rate

(i) Records that parties who take custody of gasoline additives in the gasoline 

additive distribution system must keep. Beginning January 1, 2017, all parties that take 

custody of gasoline additives for bulk addition to gasoline from the producer through to 

the party that adds the additive to gasoline must keep the following records; these 

requirements of do not apply for gasoline additives packaged for addition to gasoline in 

the vehicle fuel tank: 

(1) The product transfer document for each batch of gasoline additive.

(2) As applicable, the treatment at which the additive was added to gasoline.
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(3) As applicable, the volume of gasoline that was treated with the additive. A new 

record shall be initiated in cases where a new batch of additives is mixed into a storage 

tank from which the additive is drawn to be injected into gasoline. 

(j) Records regarding credits. The records required under this subpart O shall be 

kept for five years from the date they were created; except in the following cases:

(1) Transfers of credits. Except as provided in paragraph (f)(2) of this section, 

records relating to credit transfers shall be kept by the transferor for five years from the 

date the credits are transferred; and shall be kept by the transferee for five years from the 

date the credits were transferred, used, or terminated, whichever is later.

(2) Credits generated prior to January 1, 2017. (i) Where the party generating the 

credits does not transfer the credits, records must be kept for five years from the date of 

creation, use, or termination, whichever is later.

(ii) When credits generated prior to January 1, 2017 are transferred, records relating 

to such credits shall be kept by the transferor for five years from the date the credits are 

transferred; and shall be kept by the transferee for five years from the date the credits 

were transferred, used, or terminated, whichever is later.

(k) Make records available to EPA. On request by EPA, the records required in this 

section shall be provided to the Administrator’s authorized representative. For records 

that are electronically generated or maintained, the equipment and software necessary to 

read the records shall be made available; or, if requested by EPA, electronic records shall 

be converted to paper documents which shall be provided to the Administrator’s 

authorized representative.

§ 80.1654 California gasoline requirements.

(a) California gasoline exemption. California gasoline that complies with all the 

requirements of this section is exempt from all other provisions of this subpart O.

(b) Requirements for California gasoline. (1) Each batch of California gasoline must 

be designated as such by its refiner or importer.

(2) Designated California gasoline must be kept segregated from gasoline that is not 

California gasoline, at all points in the distribution system.

(3) Designated California gasoline must ultimately be used in the State of California 

and not used elsewhere.

(4) For California gasoline produced outside the State of California, the transferors 

and transferees must meet the product transfer document requirements of paragraph 

(b)(5) of this section.

(5)(i) Any refiner that operates a refinery located outside the State of California at 

which California gasoline (as defined in § 80.1600) is produced must provide to any

person to whom custody or title of such gasoline has transferred, and each transferee 
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must provide to any subsequent transferee, documents which include all the following 

information:

(A) The name and address of the transferor.

(B) The name and address of the transferee.

(C) The volume of gasoline which is being transferred.

(D) The location of the gasoline at the time of the transfer.

(E) The date and time of the transfer.

(F) The identification of the gasoline as California gasoline.

(ii) Each refiner and transferee of California gasoline must maintain copies of the 

product transfer documents required to be provided by paragraph (b)(5)(i) of this section 

for a period of five years from the date of creation and shall deliver such documents to 

the Administrator or to the Administrator’s authorized representative upon request.

(6) Gasoline that is ultimately used in any part of the United States outside of the 

State of California must comply with the standards and requirements of this subpart, 

regardless of any designation as California gasoline.

(c) Use of California test methods and offsite sampling procedures. In the case of 

any gasoline that is not California gasoline and that is either produced at a refinery

located in the State of California or is imported from outside the United States into the 

State of California, the refiner or importer may, with regard to such gasoline–

(1) Use the sampling and testing methods approved in Title 13 of the California Code 

of Regulations instead of the sampling and testing methods required under § 80.1630; and

(2) Determine the sulfur content of gasoline at offsite tankage (which would 

otherwise be prohibited under § 80.65(e)(1)). Note that the requirements of § 

80.65(e)(1), regarding when the properties of a batch of reformulated gasoline must be 

determined, specify that the properties of a batch of gasoline be determined prior to the 

gasoline leaving the refinery or import facility; however, under this section, a refiner of 

California gasoline may determine the properties of gasoline as specified under § 

80.65(e)(1) at offsite tankage provided that–

(i) The samples are properly collected under the terms of a current and valid protocol 

agreement between the refiner and the California Air Resources Board with regard to 

sampling at the offsite tankage and consistent with the requirements prescribed in Title 

13, California Code of Regulations, section 2250 et seq. (May 1, 2003); and

(ii) The refiner provides a copy of the protocol agreement to EPA upon request.

§ 80.1655 National security exemption.

(a) The standards of § 80.1603 do not apply to gasoline that is produced, imported, 

sold, offered for sale, supplied, offered for supply, stored, dispensed, or transported for 

use in any of the following:

(1) Tactical military vehicles, engines, or equipment having an EPA national security

exemption from the gasoline emission standards under 40 CFR part 86.
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(2) Tactical military vehicles, engines, or equipment that are not subject to a national 

security exemption from vehicle or engine emissions standards as described in paragraph 

(a)(1) of this section but, for national security purposes (for purposes of readiness for 

deployment overseas), need to be fueled on the same gasoline as the vehicles, engines, or 

equipment for which EPA has granted such a national security exemption.

(b) The exempt fuel must meet all the following conditions:

(1) It must be accompanied by product transfer documents as required under § 

80.1651.

(2) It must be segregated from non-exempt gasoline at all points in the distribution 

system.

(3) It must be dispensed from a fuel pump stand, fueling truck, or tank that is labeled 

with the appropriate designation of the fuel.

(4) It may not be used in any vehicles, engines, or equipment other than those 

referred to in paragraph (a) of this section.

(c) Any national security exemptions approved under subpart H of this part will 

remain in place under this subpart O.

§ 80.1656 Exemptions for gasoline used for research, development, or testing 

purposes.

(a) Written request for a research and development exemption. Any person may

receive an exemption from the provisions of this subpart for gasoline used for research, 

development, or testing (“R&D”) purposes by submitting the information listed in 

paragraph (c) of this section to EPA. Applications for R&D exemptions must be 

submitted to the address in paragraph (h) of this section.

(b) Criteria for a research and development exemption. For a research and 

development exemption to be granted, the person requesting an exemption must do all the 

following:

(1) Demonstrate a purpose that constitutes an appropriate basis for exemption.

(2) Demonstrate that an exemption is necessary.

(3) Design a research and development program that is reasonable in scope.

(4) Have a degree of control consistent with the purpose of the program and EPA’s 

monitoring requirements. 

(c) Information required to be submitted. To demonstrate each of the elements in 

paragraph (b) of this section, the person requesting an exemption must include all the 

following information:

(1) A concise statement of the purpose of the program demonstrating that the 

program has an appropriate research and development purpose.
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(2) An explanation of why the stated purpose of the program cannot be achieved in a 

practicable manner without performing one or more of the prohibited acts under this 

subpart O.

(3) All the following, to demonstrate the reasonableness of the scope of the program:

(i) An estimate of the program’s beginning and ending dates.

(ii) An estimate of the maximum number of vehicles or engines involved in the 

program and the number of miles and engine hours that will be accumulated on each.

(iii) The sulfur content of the gasoline expected to be used in the program.

(iv) The quantity of gasoline which does not comply with the requirements of § 

80.1603.

(v) The manner in which the information on vehicles and engines used in the program 

will be recorded and made available to the Administrator upon request.

(4) With regard to control, a demonstration that the program affords EPA a 

monitoring capability, including all the following:

(i) A description of the technical and operational aspects of the program.

(ii) The site(s) of the program (including facility name, street address, city, county, 

state, and zip code).

(iii) The manner in which information on the fuel used in the program (including 

quantity, fuel properties, name, address, telephone number and contact person of the 

supplier, and the date received from the supplier), will be recorded and made available to 

the Administrator upon request.

(iv) The manner in which the party will ensure that the research and development fuel 

will be segregated from gasoline meeting the standards of this subpart and how fuel 

pumps will be labeled to ensure proper use of the research and development fuel.

(v) The name, address, telephone number, and title of the person(s) in the 

organization requesting an exemption from whom further information on the application 

may be obtained.

(vi) The name, address, telephone number, and title of the person(s) in the 

organization requesting an exemption who is responsible for recording and making 

available the information specified in this paragraph (c), and the location where such 

information will be maintained.

(d) Additional requirements. (1) The product transfer documents associated with 

research and development gasoline must comply with requirements of § 80.1651(c).

(2) The research and development gasoline must be designated by the refiner or 

supplier, as applicable, as exempt research and development gasoline.

(3) The research and development gasoline must be kept segregated from non-exempt 

gasoline at all points in the distribution system.

(4) The research and development gasoline must not be sold, distributed, offered for 

sale or distribution, dispensed, supplied, offered for supply, transported to or from, or 

stored by a fuel retail outlet, or by a wholesale purchaser-consumer facility, unless the 

wholesale purchaser-consumer facility is associated with the research and development 

program that uses the gasoline.
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(5) At the completion of the program, any emission control systems or elements of 

design which are damaged or rendered inoperative shall be replaced on vehicles 

remaining in service, or the responsible person will be liable for a violation of the Clean 

Air Act section 203(a)(3) (42 U.S.C. 7522 (a)(3)) unless sufficient evidence is supplied 

that the emission controls or elements of design were not damaged.

(e) Memorandum of exemption. The Administrator will grant an R&D exemption 

upon a demonstration that the requirements of this section have been met. The R&D 

exemption will be granted in the form of a memorandum of exemption signed by the 

applicant and the Administrator (or delegate), which may include such terms and 

conditions as the Administrator determines necessary to monitor the exemption and to 

carry out the purposes of this section, including restoration of emission control systems.

(1) The volume of fuel subject to the approval shall not exceed the estimated amount 

under paragraph (c)(3) of this section, unless EPA grants a greater amount in writing.

(2) Any exemption granted under this section will expire at the completion of the test 

program or three years from the date of approval, whichever occurs first, and may only 

be extended upon re-application consistent will all requirements of this section.

(3) EPA may elect at any time to review the information contained in the request, and 

where appropriate may notify the responsible person of disapproval of the exemption.

(4) In granting an exemption the Administrator may include terms and conditions, 

including replacement of emission control devices or elements of design, that the 

Administrator determines are necessary for monitoring the exemption and for assuring 

that the purposes of this subpart are met.

(5) Any violation of a term or condition of the exemption, or of any requirement of 

this section, will cause the exemption to be void ab initio.

(6) If any information required under paragraph (c) of this section should change after 

approval of the exemption, the responsible person must notify EPA in writing 

immediately. Failure to do so may result in disapproval of the exemption or may make it 

void ab initio, and may make the party liable for a violation of this subpart O.

(f) Effects of exemption. Gasoline that is subject to a research and development 

exemption under this section is exempt from other provisions of this subpart O provided 

that the fuel is used in a manner that complies with the purpose of the program under 

paragraph (c) of this section and all other requirements of this section.

(g) Notification of completion. The party shall notify EPA in writing within 30 days 

after completion of the research and development program.

(h) Submission. Requests for research and development exemptions shall be sent to 

the following address: U.S. EPA—Attn: Tier 3 Program (R&D Exemption Request), 

6406J, 1200 Pennsylvania Avenue, NW., Washington, DC 20460.

§ 80.1657 [Reserved]
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§ 80.1658 Requirements for gasoline for use in American Samoa, Guam, and the 

Commonwealth of the Northern Mariana Islands.

The gasoline sulfur standards of this subpart O do not apply to gasoline that is produced, 

imported, sold, offered for sale, supplied, offered for supply, stored, dispensed, or 

transported for use in the Territories of Guam, American Samoa or the Commonwealth of 

the Northern Mariana Islands, provided that such gasoline meets all the following 

requirements:

(a) The gasoline is designated by the refiner or importer as high sulfur gasoline only

for use in Guam, American Samoa, or the Commonwealth of the Northern Mariana 

Islands.

(b) The gasoline is used only in Guam, American Samoa, or the Commonwealth of 

the Northern Mariana Islands.

(c) The gasoline is accompanied by documentation that complies with the product 

transfer document requirements of § 80.1651(c)(3).

(d) The gasoline is segregated from non-exempt high sulfur gasoline at all points in 

the distribution system from the point the fuel is designated as gasoline only for use in 

Guam, American Samoa, or the Commonwealth of the Northern Mariana Islands, while 

the fuel is in the United States but outside these Territories.

§ 80.1659 [Reserved]

§ 80.1660 Prohibited acts.

No person shall:

(a) Averaging violation. Produce or import gasoline that does not comply with the 

applicable sulfur average standard under § 80.1603.

(b) Cap standard violation. Produce, import, sell, offer for sale, dispense, supply, 

offer for supply, store or transport gasoline, oxygenate, or ethanol denaturant that does 

not comply with the applicable sulfur cap standards under § 80.1603, § 80.1604, § 

80.1610, or § 80.1611.

(c) Causing violating gasoline, oxygenate, or ethanol denaturant to be in the 

distribution system. Cause gasoline, oxygenate, or ethanol denaturant to be in the 
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distribution system which does not comply with an applicable sulfur cap standard under § 

80.1603, § 80.1604, § 80.1610, or § 80.1611. 

(d) Oxygenate violation. Starting March 1, 2017, blend into gasoline, RBOB, or 

CBOB any oxygenate, including but not limited to denatured fuel ethanol, that has a 

sulfur content higher than 10 ppm.

(e) Additive blender violation. Unless acting in the capacity of a gasoline refiner or 

importer under § 80.1613, introduce an additive other than an oxygenate compound into 

gasoline, CBOB, or RBOB which contributes more than 3 ppm to the sulfur content of 

the finished gasoline, CBOB, or RBOB.

(f) Additive manufacturer violation. Introduce an additive with a maximum allowed 

treatment rate of less than 1.0 volume percent into gasoline, CBOB, or RBOB which 

contributes more than 3 ppm to the sulfur content of the finished gasoline, CBOB, or 

RBOB, or introduce more than 1.0 volume percent of any additive other than an 

oxygenate into gasoline, CBOB, or RBOB without complying with all of the 

requirements of Subpart O, including the standards and requirements at § 80.1640 that 

apply to refiners producing gasoline by blending blendstocks into PCG. 

(g) Denaturant violation. Cause or contribute to the introduction into commerce of an 

ethanol denaturant designated as suitable for the production manufacture of denatured 

fuel ethanol meeting federal quality requirements which does not comply with the 

requirements of § 80.1611.

(h) Credit violation. Generate, transfer, or use invalid credits or improperly transfer 

or use credits.

(i) Export violation. Distribute or dispense gasoline intended for export (pursuant to 

§ 80.1603(b)(3)) for use in the United States.

(j) Failure to meet a requirement. Fail to meet a requirement that applies to that 

person under this subpart.

§ 80.1661 What evidence may be used to determine compliance with the 

prohibitions and requirements of this subpart and liability for violations of this 

subpart?

(a) Compliance with the sulfur standards of this subpart O shall be determined based 

on the sulfur level, measured or otherwise determined as applicable using the 

methodologies specified in §§ 80.47, 80.1611, and 80.1630. Any evidence or 

information, including the exclusive use of such evidence or information, may be used to 

establish the sulfur level of gasoline, ethanol denaturant, or oxygenate if the evidence or 
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information is relevant to whether the sulfur level would have been in compliance with 

the standards if the appropriate sampling and testing methodology or other sulfur 

determination methodology as applicable had been correctly performed. Such evidence 

may be obtained from any source or location and may include, but is not limited to, test 

results using methods other than those specified in §§ 80.47 and 80.1630, business 

records, and commercial documents.

(b) Determinations of compliance with the requirements of this subpart other than the 

sulfur standards, and determinations of liability for any violation of this subpart, may be 

based on information obtained from any source or location. Such information may

include, but is not limited to, business records and commercial documents.

§ 80.1662 Liability for violations.

The following persons are liable for violations under this subpart:

(a) Persons liable for violations of prohibited acts. (1) Averaging violation. Any

refiner or importer who violates § 80.1660(a) is liable for the violation.

(2) Causing an averaging violation. Any refiner, importer, distributor, reseller, 

carrier, retailer, wholesale purchaser-consumer, oxygenate blender, ethanol denaturant 

producer, or ethanol denaturant importer who causes another party to violate § 

80.1660(a), is liable for a violation of § 80.1660(c).

(3) Cap standard violation. Any refiner, gasoline importer, distributor, reseller, 

carrier, retailer, wholesale purchaser-consumer, oxygenate producer, oxygenate importer, 

oxygenate blender, ethanol denaturant producer, ethanol denaturant importer, additive 

manufacturer, or additive blender who owned, leased, operated, controlled or supervised 

a facility where a violation of § 80.1660(b) occurred, is deemed in violation of § 

80.1660(b).

(4) Causing a cap standard violation. Any refiner, gasoline importer, distributor, 

reseller, carrier, retailer, wholesale purchaser-consumer, oxygenate producer, oxygenate 

importer, oxygenate blender, ethanol denaturant producer, ethanol denaturant importer, 

additive manufacturer, or additive blender who produced, imported, sold, offered for sale, 

dispensed, supplied, offered for supply, stored, transported, or caused the transportation 

or storage of gasoline, oxygenate, or ethanol denaturant that violates § 80.1660(b), is 

deemed in violation of § 80.1660(c).

(5) Branded refiner/importer liability. Any refiner or importer whose corporate, 

trade, or brand name, or whose marketing subsidiary’s corporate, trade, or brand name 

appeared at a facility where a violation of § 80.1660(b) occurred, is deemed in violation 

of § 80.1660(b).

(6) Causing violating gasoline to be in the distribution system. Any refiner, gasoline 

importer, distributor, reseller, carrier, oxygenate producer, oxygenate importer, oxygenate 

blender, ethanol denaturant producer, ethanol denaturant importer, additive manufacturer, 

or additive blender who owned, leased, operated, controlled or supervised a facility from 
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which gasoline, oxygenate, or ethanol denaturant was released into the distribution 

system which does not comply with an applicable sulfur cap standard or a sulfur 

averaging standard is deemed in violation of § 80.1660(d).

(7) Carrier causation. In order for a carrier to be liable under paragraph (a)(2), (a)(3), 

(a)(4), or (a)(6) of this section, EPA must demonstrate, by reasonably specific showing 

by direct or circumstantial evidence, that the carrier caused the violation.

(8) Oxygenate blender violation. Any oxygenate blender who violates § 80.1660(e) 

is liable for the violation.

(9) Additive manufacturer violation. Any additive manufacturer who violates § 

80.1660(g) is deemed liable for the violation.

(10) Additive blender violation. Any additive blender who violates § 80.1660(f) is 

deemed liable for the violation.

(11) Credit violation. Any refiner or importer who violates § 80.1660(h) is liable for 

the violation.

(12) Parent corporation liability. Any parent corporation is liable for any violations of 

this subpart that are committed by any of its wholly-owned subsidiaries.

(13) Joint venture and joint owner liability. Each partner to a joint venture, or each 

owner of a facility owned by two or more owners, is jointly and severally liable for any 

violation of this subpart that occurs at the joint venture facility or facility owned by the 

joint owners, or is committed by the joint venture operation or any of the joint owners of 

the facility.

(b) Persons liable for failure to meet other provisions of this subpart. Any person 

who–

(1) Fails to comply with a provision of this subpart not addressed in paragraph (a) of 

this section is liable for a violation of that provision.

(2) Causes another person to fail to meet a requirement of this subpart not addressed 

in paragraph (a) of this section is liable for causing a violation of that provision.

§ 80.1663 Defenses for a violation of a prohibited act.

(a) Any person deemed liable for a violation of a prohibition under § 80.1662(a)(3) 

through (10), will not be deemed in violation if the person demonstrates all the following:

(1) The violation was not caused by the person or the person’s employee or agent.

(2) In cases where product transfer document requirements under this subpart apply, 

the product transfer documents account for the fuel found to be in violation and indicate 

that the violating product was in compliance with the applicable requirements while in 

that person’s control; and

(3) The person conducted a quality assurance sampling and testing program, as 

described in paragraph (d) of this section. A carrier may rely on the quality assurance 

program carried out by another party, including the party who owns the gasoline in 

question, provided that the quality assurance program is carried out properly. Retailers 
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and wholesale purchaser-consumers are not required to conduct sampling and testing of 

gasoline as part of their quality assurance programs.

(b) In the case of a violation found at a facility operating under the corporate, trade or 

brand name of a refiner or importer, or a refiner’s or importer’s marketing subsidiary, the 

refiner or importer must show, in addition to the defense elements required under 

paragraphs (a)(1) through (3) of this section, that the violation was caused by any of the 

following:

(1) An act in violation of law (other than the Clean Air Act or this part 80), or an act 

of sabotage or vandalism.

(2) The action of any refiner, gasoline importer, retailer, distributor, reseller, 

oxygenate blender, carrier, retailer or wholesale purchaser-consumer in violation of a 

contractual agreement between the branded refiner or importer and the person designed to 

prevent such action, and despite periodic sampling and testing by the branded refiner or 

importer to ensure compliance with such contractual obligation.

(3) The action of any carrier or other distributor not subject to a contract with the 

refiner or importer, but engaged for transportation of gasoline, oxygenate, or ethanol 

denaturant despite specifications or inspections of procedures and equipment which are 

reasonably calculated to prevent such action.

(c) Under paragraph (a) of this section, for any person to show that a violation was 

not caused by that person, or under paragraph (b) of this section to show that a violation 

was caused by any of the specified actions, the person must demonstrate by reasonably 

specific showings, by direct or circumstantial evidence, that the violation was caused or 

must have been caused by another person and that the person asserting the defense did 

not contribute to that other person’s causation.

(d) To demonstrate an acceptable quality assurance and testing program under 

paragraph (a)(2) of this section, a person must present evidence of all the following:

(1) A periodic sampling and testing program to ensure the gasoline the person sold, 

dispensed, supplied, stored, or transported, meets the applicable sulfur standard.

(2) On each occasion when gasoline is found not in compliance with the applicable 

sulfur standard–

(i) The person immediately ceases selling, offering for sale, dispensing, supplying, 

offering for supply, storing or transporting the non-complying product; and

(ii) The person promptly remedies the violation and the factors that caused the 

violation (for example, by removing the non-complying product from the distribution 

system until the applicable standard is achieved and taking steps to prevent future 

violations of a similar nature from occurring).

(3) For any carrier who transports gasoline in a tank truck, the quality assurance 

program required under this paragraph (d) need not include periodic sampling and testing 

of gasoline in the tank truck, but in lieu of such tank truck sampling and testing, the 

carrier shall demonstrate evidence of an oversight program for monitoring compliance 

with the requirements of this subpart relating to the transport or storage of gasoline by 
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tank truck, such as appropriate guidance to drivers regarding compliance with the 

applicable sulfur standard and product transfer document requirements, and the periodic 

review of records received in the ordinary course of business concerning gasoline quality

and delivery.

§ 80.1664 [Reserved]

§ 80.1665 Penalties.

(a) Any person liable for a violation under § 80.1662 is subject to civil penalties as 

specified in section 205 of the Clean Air Act (42 U.S.C. 7524) for every day of each such 

violation and the amount of economic benefit or savings resulting from each violation.

(b) Any person liable under § 80.1662(a)(1) or (a)(2) for a violation of the applicable 

sulfur averaging standard or causing another party to violate that standard during any 

averaging period, is subject to a separate day of violation for each and every day in the 

averaging period. Any person liable under § 80.1662(a)(11) or (b) for a failure to fulfill 

any requirement for credit generation, transfer, use, banking, or deficit correction, is 

subject to a separate day of violation for each and every day in the averaging period in 

which invalid credits are generated or used.

(c)(1) Any person liable under § 80.1662(a)(3) through (10) for a violation of an 

applicable sulfur per gallon cap standard under this subpart O or of causing another party

to violate a cap standard, is subject to a separate day of violation for each and every day

the non-complying gasoline remains any place in the gasoline distribution system.

(2) Any person liable under § 80.1662(a)(6) for causing gasoline, oxygenate, or 

ethanol denaturant to be in the distribution system which does not comply with an 

applicable sulfur cap standard, or a sulfur averaging standard, is subject to a separate day

of violation for each and every day that the non-complying gasoline, oxygenate, or 

ethanol denaturant remains any place in the gasoline, oxygenate, or ethanol denaturant 

distribution system.

(3) For purposes of this paragraph (c), the length of time the gasoline, oxygenate, or 

ethanol denaturant in question remained in the gasoline, oxygenate, or ethanol denaturant 

distribution system is deemed to be twenty-five days, unless a person subject to liability

or EPA demonstrates by reasonably specific showings, by direct or circumstantial 

evidence, that the non-complying gasoline, oxygenate, or ethanol denaturant remained in 

the gasoline, oxygenate, or ethanol denaturant distribution system for fewer than or more 

than twenty-five days.

(d) Any person liable under § 80.1662(b) for failure to meet, or causing a failure to 

meet, a provision of this subpart is liable for a separate day of violation for each and 

every day such provision remains unfulfilled.
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§ 80.1666 Additional requirements for foreign small refiners and foreign small 

volume refineries.

The provisions of this section apply to certain foreign refiners and importers during the 

period January 1, 2017 through December 31, 2019. After December 31, 2019, foreign 

refiners are not subject to compliance requirements under subpart H of this part, or this 

subpart O; instead, the importer of any foreign-produced gasoline shall be responsible for 

compliance with the standards and requirements of this subpart O that relate to importers. 

(a) Definitions. (1) Foreign small refiner is a foreign refiner that meets the definition 

of a small refiner under § 80.1620.

(2) Foreign small volume refinery is a foreign refinery that meets the definition of a 

small volume refinery under § 80.1621.

(3) Sulfur-FRGAS, for this subpart, means gasoline produced from January 1, 2017 

through December 31, 2019, at a foreign refinery of a refiner that has been approved as a 

small refiner or a small volume refinery under § 80.1622, and that is imported into the 

United States.

(4) Non-Sulfur-FRGAS means gasoline that is produced at a foreign refinery that has 

not been approved as a small refiner refinery or small volume refinery under § 80.1622, 

gasoline produced at a foreign refinery of an approved small refiner or at an approved 

small volume refinery under § 80.1622 that is not imported into the United States, and 

gasoline produced at a foreign refinery that is approved during a year when the foreign 

refiner has opted to not participate in the Sulfur-FRGAS program under paragraph (c)(3) 

of this section.

(5) Certified Sulfur-FRGAS means Sulfur-FRGAS the foreign refiner intends to 

include in the foreign refinery’s sulfur compliance calculations under §§ 80.195 and 

80.205 and does include in these compliance calculations when reported to EPA.

(6) Non-Certified Sulfur-FRGAS means Sulfur-FRGAS that is not Certified SulfurFRGAS.

(b) Petition for approval of small refiner or small volume refinery status. To be 

approved for small refiner status or small volume refinery status a foreign refiner must 

submit a petition for approval as provided under § 80.1622 and this section. If small 

refiner status or small volume refinery status is approved, the foreign refiner may produce 

gasoline for export to the United States, during the period starting January 1, 2017 and 

ending December 31, 2019, that is subject to the sulfur content standards of subpart H of 

this part at § 80.195 that were applicable to refiners from 2006 through 2016. A foreign 

refiner is not eligible to generate sulfur credits under subpart H of this part or this subpart 

O, as this occurs through the importer. 

(c) General requirements for foreign refiners approved as small refiners or small 

volume refinery status. A foreign refiner of a refinery that has been approved as a small 
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refiner refinery or a small volume refinery must designate all gasoline produced at the 

foreign refinery that is exported to the United States as either Certified Sulfur-FRGAS or 

as Non-Certified Sulfur-FRGAS, except as provided in paragraph (c)(3) of this section. 

(1) In the case of Certified Sulfur-FRGAS, the foreign refiner must meet the sulfur 

standards of subpart H of this part as described in paragraph (b) of this section and the 

requirements of this section.

(2) In the case of Non-Certified Sulfur-FRGAS, the foreign refiner shall meet all the 

following provisions, except the foreign refiner shall substitute the name Non-Certified 

Sulfur-FRGAS for the names “reformulated gasoline” or “RBOB” wherever they appear 

in the following provisions:

(i) The designation requirements in this section.

(ii) The recordkeeping requirements under § 80.1653.

(iii) The reporting requirements in § 80.1652 and this section.

(iv) The product transfer document requirements in § 80.1651 and this section.

(v) The prohibitions in § 80.1660 and this section.

(vi) The independent audit requirements under § 80.415 and paragraph (h) of this 

section; and the attest engagement provisions of §§ 80.125 through 80.127, 80.128(a), 

(b), (c), and (g) through (i), and 80.130.

(3)(i) Any foreign refiner that has been approved as a small refiner or whose refinery

has been approved as a small volume refinery under this subpart O may elect to classify

no gasoline imported into the United States as Sulfur-FRGAS, provided the foreign 

refiner notifies EPA of the election no later than November 1 of the prior calendar year. 

(ii) An election under paragraph (c)(3)(i) of this section shall meet all the following 

requirements:

(A) Apply to an entire calendar year averaging period, and apply to all gasoline 

produced during the calendar year at the foreign refinery that is used in the United States.

(B) Remain in effect for each succeeding calendar year averaging period, unless and 

until the foreign refiner notifies EPA of a termination of the election. The change in 

election shall take effect at the beginning of the next calendar year.

(d) Designation, product transfer documents, and foreign refiner certification. (1) 

Any approved foreign small refiner or any foreign refiner having an approved small 

volume refinery under this subpart O must designate each batch of Sulfur-FRGAS as 

such at the time the gasoline is produced, unless the refinery has elected to classify no 

gasoline exported to the United States as Sulfur-FRGAS under paragraph (c)(3)(i) of this 

section.

(2) On each occasion when any person transfers custody or title to any SulfurFRGAS prior to its being imported into the United States, it must include all the 

following information as part of the product transfer document information in this 

section:

(i) Identification of the gasoline as Certified Sulfur-FRGAS or as Non-Certified 

Sulfur-FRGAS.

(ii) The name and EPA refinery registration number of the refinery where the SulfurFRGAS was produced.
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(3) On each occasion when Sulfur-FRGAS is loaded onto a vessel or other 

transportation mode for transport to the United States, the foreign refiner shall prepare a 

certification for each batch of the Sulfur-FRGAS that meets all the following 

requirements:

(i) The certification shall include the report of the independent third party under 

paragraph (f) of this section, and all the following additional information:

(A) The name and EPA registration number of the refinery that produced the SulfurFRGAS.

(B) The identification of the gasoline as Certified Sulfur-FRGAS or Non-Certified 

Sulfur-FRGAS.

(C) The volume of Sulfur-FRGAS being transported, in gallons.

(D) In the case of Certified Sulfur-FRGAS, the sulfur content as determined under 

paragraph (f) of this section, and a declaration that the Sulfur-FRGAS is being included 

in the compliance calculations under § 80.205 for the refinery that produced the SulfurFRGAS.

(ii) The certification shall be made part of the product transfer documents for the 

Sulfur-FRGAS.

(e) Transfers of Sulfur-FRGAS to non-U.S. markets. The foreign refiner is 

responsible to ensure that all gasoline classified as Sulfur-FRGAS is imported into the 

United States. A foreign refiner may remove the Sulfur-FRGAS classification, and the 

gasoline need not be imported into the United States, but only if–

(1)(i) The foreign refiner excludes the volume and sulfur content of the gasoline from 

the compliance calculations under § 80.205.

(ii) The exclusions under paragraph (e)(1)(i) of this section shall be on the basis of the 

sulfur content and volumes determined under paragraph (f) of this section; and

(2) The foreign refiner obtains sufficient evidence in the form of documentation that 

the gasoline was not imported into the United States.

(f) Load port independent sampling, testing and refinery identification. (1) On each 

occasion Sulfur-FRGAS is loaded onto a vessel for transport to the United States a 

foreign refiner shall have an independent third party do all the following:

(i) Inspect the vessel prior to loading and determine the volume of any tank bottoms.

(ii) Determine the volume of Sulfur-FRGAS loaded onto the vessel (exclusive of any 

tank bottoms present before vessel loading).

(iii) Obtain the EPA-assigned registration number of the foreign refinery.

(iv) Determine the name and country of registration of the vessel used to transport the 

Sulfur-FRGAS to the United States.

(v) Determine the date and time the vessel departs the port serving the foreign 

refinery.

(2) On each occasion Certified Sulfur-FRGAS is loaded onto a vessel for transport to 

the United States a foreign refiner shall have an independent third party–
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(i) Collect a representative sample of the Certified Sulfur-FRGAS from each vessel 

compartment subsequent to loading on the vessel and prior to departure of the vessel 

from the port serving the foreign refinery.

(ii) Prepare a volume-weighted vessel composite sample from the compartment 

samples, and determine the value for sulfur in accordance with the methodology and 

requirements specified in § 80.1630, by either of the following:

(A) The third party analyzing the sample.

(B) The third party observing the foreign refiner analyzing the sample.

(iii) Review original documents that reflect movement and storage of the certified 

Sulfur-FRGAS from the refinery to the load port, and from this review determine all the 

following:

(A) The refinery at which the Sulfur-FRGAS was produced.

(B) That the Sulfur-FRGAS remained segregated from Non-Sulfur-FRGAS, NonCertified Sulfur-FRGAS, and other Certified Sulfur-FRGAS produced at a different 

refinery.

(3) The independent third party shall submit a report–

(i) To the foreign refiner containing the information required under paragraphs (f)(1) 

and (2) of this section, to accompany the product transfer documents for the vessel; and

(ii) To the Administrator containing the information required under paragraphs (f)(1) 

and (2) of this section, within thirty days following the date of the independent third 

party’s inspection. This report shall include a description of the method used to 

determine the identity of the refinery at which the gasoline was produced, assurance that 

the gasoline remained segregated as specified in paragraph (m)(1) of this section, and a 

description of the gasoline’s movement and storage between production at the source 

refinery and vessel loading.

(4) The independent third party must do all the following:

(i) Be approved in advance by EPA, based on a demonstration of ability to perform 

the procedures required in this paragraph (f).

(ii) Be independent under the criteria specified in § 80.65(f)(2)(iii).

(iii) Sign a commitment that contains the provisions specified in paragraph (i) of this 

section with regard to activities, facilities and documents relevant to compliance with the 

requirements of this paragraph (f).

(g) Comparison of load port and port of entry testing. (1)(i) Except as described in 

paragraph (g)(1)(ii) of this section, any foreign refiner and any U.S. importer of Certified 

Sulfur-FRGAS shall compare the results from the load port testing under paragraph (f) of 

this section, with the port of entry testing as reported under paragraph (o) of this section, 

for the volume of gasoline and the sulfur value.

(ii) Where a vessel transporting Certified Sulfur-FRGAS off loads this gasoline at 

more than one U.S. port of entry, and the conditions of paragraph (g)(2) of this section 

are met at the first U.S. port of entry, the requirements of paragraph (g)(2) of this section 

do not apply at subsequent ports of entry if the U.S. importer obtains a certification from 

the vessel owner, meeting the requirements of paragraph (r) of this section that the vessel 
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has not loaded any gasoline or blendstock between the first U.S. port of entry and the 

subsequent port of entry.

(2) The U.S. importer and the foreign refiner shall treat the gasoline as Non-Certified 

Sulfur-FRGAS, and the foreign refiner shall exclude the gasoline volume and properties 

from its gasoline sulfur compliance calculations under § 80.205 under either of the 

following circumstances:

(i) The temperature-corrected volumes determined at the port of entry and at the load 

port differ by more than one percent.

(ii) The sulfur value determined at the port of entry is higher than the sulfur value 

determined at the load port, and the amount of this difference is greater than the 

reproducibility amount specified for the port of entry test result by ASTM.

(h) Attest requirements. All the following additional procedures shall be carried out 

by any foreign refiner of Sulfur-FRGAS as part of the applicable attest engagement for 

each foreign refinery under § 80.415:

(1) The inventory reconciliation analysis under the attest engagement provisions of § 

80.128(b) and the tender analysis under § 80.128(c) shall include Non-Sulfur-FRGAS in 

addition to the gasoline types listed in § 80.128(b) and (c).

(2) Obtain separate listings of all tenders of Certified Sulfur-FRGAS, and of NonCertified Sulfur-FRGAS. Agree the total volume of tenders from the listings to the 

gasoline inventory reconciliation analysis in the attest engagement provisions of § 

80.128(b), and to the volumes determined by the third party under paragraph (f)(1) of this 

section.

(3) For each tender under paragraph (h)(2) of this section where the gasoline is 

loaded onto a marine vessel, report as a finding the name and country of registration of 

each vessel, and the volumes of Sulfur-FRGAS loaded onto each vessel.

(4) Select a sample from the list of vessels identified in paragraph (h)(3) of this 

section used to transport Certified Sulfur-FRGAS, in accordance with the attest 

engagement guidelines in § 80.127, and for each vessel selected perform all the 

following:

(i) Obtain the report of the independent third party, under paragraph (f) of this 

section, and of the U.S. importer under paragraph (n) of this section.

(A) Agree the information in these reports with regard to vessel identification, 

gasoline volumes and test results.

(B) Identify, and report as a finding, each occasion the load port and port of entry

parameter and volume results differ by more than the amounts allowed in paragraph (g) 

of this section, and determine whether the foreign refiner adjusted its refinery

calculations as required in paragraph (g) of this section.

(ii) Obtain the documents used by the independent third party to determine 

transportation and storage of the Certified Sulfur-FRGAS from the refinery to the load 

port, under paragraph (f) of this section. Obtain tank activity records for any storage tank 

where the Certified Sulfur-FRGAS is stored, and pipeline activity records for any

pipeline used to transport the Certified Sulfur-FRGAS, prior to being loaded onto the 

vessel. Use these records to determine whether the Certified Sulfur-FRGAS was 
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produced at the refinery that is the subject of the attest engagement, and whether the 

Certified Sulfur-FRGAS was mixed with any Non-Certified Sulfur-FRGAS, Non-SulfurFRGAS, or any Certified Sulfur-FRGAS produced at a different refinery.

(5) Select a sample from the list of vessels identified in paragraph (h)(3) of this 

section used to transport certified and Non-Certified Sulfur-FRGAS, in accordance with 

the attest engagement guidelines of § 80.127, and for each vessel selected perform the 

following:

(i) Obtain a commercial document of general circulation that lists vessel arrivals and 

departures, and that includes the port and date of departure of the vessel, and the port of 

entry and date of arrival of the vessel.

(ii) Agree the vessel’s departure and arrival locations and dates from the independent 

third party and U.S. importer reports to the information contained in the commercial 

document.

(6) Obtain separate listings of all tenders of Non-Sulfur-FRGAS, and perform all the 

following:

(i) Agree the total volume of tenders from the listings to the gasoline inventory 

reconciliation analysis in § 80.128(b).

(ii) Obtain a separate listing of the tenders under this paragraph (h)(6) where the 

gasoline is loaded onto a marine vessel. Select a sample from this listing in accordance 

with the guidelines in § 80.127, and obtain a commercial document of general circulation 

that lists vessel arrivals and departures, and that includes the port and date of departure 

and the ports and dates where the gasoline was off loaded for the selected vessels. 

Determine and report as a finding the country where the gasoline was off loaded for each 

vessel selected.

(7) In order to complete the requirements of this paragraph (h) an auditor must–

(i) Be independent of the foreign refiner.

(ii) Be licensed as a Certified Public Accountant in the United States and a citizen of 

the United States, or be approved in advance by EPA based on a demonstration of ability

to perform the procedures required in the attest engagement provisions of §§ 80.125 

through 80.130, 80.415 and this paragraph (h).

(iii) Sign a commitment that contains the provisions specified in this paragraph (h) 

with regard to activities and documents relevant to compliance with the requirements of 

the attest engagement provisions of §§ 80.125 through 80.130, 80.415 and this paragraph 

(h).

(i) Foreign refiner commitments. Any foreign refiner shall commit to and comply

with the following provisions as a condition to being approved for small refiner status or 

small volume refinery status:

(1) Any U.S. EPA inspector or auditor will be givencomplete and immediate access 

to conduct inspections and audits of the foreign refinery.

(i) Inspections and audits may be either announced in advance by EPA, or 

unannounced.

(ii) Access will be provided to any location where–

(A) Gasoline is produced;
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(B) Documents related to refinery operations are kept;

(C) Gasoline or blendstock samples are tested or stored; and

(D) Sulfur-FRGAS is stored or transported between the foreign refinery and the 

United States, including storage tanks, vessels and pipelines.

(iii) Inspections and audits may be by EPA employees or contractors to EPA.

(iv) Any documents requested that are related to matters covered by inspections and 

audits will be provided to an EPA inspector or auditor on request.

(v) Inspections and audits by EPA may include review and copying of any documents 

related to all the following:

(A) Approval of the refiner as a small refiner or approval of the refinery as a small 

volume refinery.

(B) The volume and sulfur content of Sulfur-FRGAS.

(C) The proper classification of gasoline as being Sulfur-FRGAS or as not being 

Sulfur-FRGAS, or as Certified Sulfur-FRGAS or as Non-Certified Sulfur-FRGAS.

(D) Transfers of title or custody to Sulfur-FRGAS.

(E) Sampling and testing of Sulfur-FRGAS.

(F) Work performed and reports prepared by independent third parties and by 

independent auditors under the requirements of this section and § 80.415, including work 

papers.

(G) Reports prepared for submission to EPA, and any work papers related to such 

reports.

(vi) Inspections and audits by EPA may include taking samples of gasoline or 

blendstock, and interviewing employees.

(vii) Any employee of the foreign refiner must be made available for interview by the 

EPA inspector or auditor, on request, within a reasonable time period.

(viii) English language translations of any documents must be provided to an EPA 

inspector or auditor, on request, within 10 working days.

(ix) English language interpreters must be provided to accompany EPA inspectors and 

auditors, on request.

(2) An agent for service located in the District of Columbia will be named. Service 

on this agent constitutes service on the foreign refiner or any employee of the foreign 

refiner for any action by EPA or otherwise by the United States related to the 

requirements of this subpart O.

(3) The forum for any civil or criminal enforcement action related to the provisions of 

this section for violations of the Clean Air Act or regulations promulgated thereunder 

shall be governed by the Clean Air Act, including the EPA administrative forum where 

allowed under the Clean Air Act.

(4) The substantive and procedural laws of the United States shall apply to any civil

or criminal enforcement action against the foreign refiner or any employee of the foreign 

refiner related to the provisions of this section.

(5) Submitting a petition for approval as a small refiner or for small volume refinery

status, producing and exporting gasoline under such approval, and all other actions to 

comply with the requirements of this subpart O constitute actions or activities that satisfy

the provisions of 28 U.S.C. 1605(a)(2), but solely with respect to actions instituted 
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against the foreign refiner, its agents and employees in any court or other tribunal in the 

United States for conduct that violates the requirements applicable to the foreign refiner 

under this subpart O, including conduct that violates 18 U.S.C. 1001 or Clean Air Act 

section 113(c)(2) (42 U.S.C. 7413(c)(2)).

(6) The foreign refiner, or its agents or employees, must not seek to detain or to 

impose civil or criminal remedies against EPA inspectors or auditors, whether EPA 

employees or EPA contractors, for actions performed within the scope of EPA 

employment related to the provisions of this section.

(7) The commitment required by this paragraph (i) must be signed by the owner or 

president of the foreign refiner business.

(8) In any case where FRGAS produced at a foreign refinery is stored or transported 

by another company between the refinery and the vessel that transports the SulfurFRGAS to the United States, the foreign refiner shall obtain from each such other 

company a commitment that meets the requirements specified in paragraphs (i)(1) 

through (7) of this section.

(j) Sovereign immunity. By submitting a petition for approval as a small refiner or 

approval of a small volume refinery under this subpart O and this section, or by

producing and exporting gasoline to the United States under such an approval under this 

section, the foreign refiner, its agents and employees, without exception, become subject 

to the full operation of the administrative and judicial enforcement powers and provisions 

of the United States without limitation based on sovereign immunity, with respect to 

actions instituted against the foreign refiner, its agents and employees in any court or 

other tribunal in the United States for conduct that violates the requirements applicable to 

the foreign refiner under this subpart O, including conduct that violates 18 U.S.C. 1001 or 

Clean Air Act section 113(c)(2) (42 U.S.C. 7413(c)(2)).

(k) Bond posting. Any foreign refiner must meet the following requirements as a 

condition to being approved for small refiner or small volume refinery status:

(l) The foreign refiner shall post a bond of the amount calculated using the following 

equation:

Bond=G×$ 0.01

Where:

Bond = Amount of the bond in U. S. dollars.

G = The largest volume of gasoline produced at the foreign refinery and 

exported to the United States, in gallons, during a single calendar year among the most 

recent of the following calendar years, up to a maximum of three calendar years: the 

calendar year immediately preceding the date the approval petition is submitted, the 

calendar year the approval petition is submitted, and each succeeding calendar year.

(2) Bonds shall be posted by performing any of the following:

(i) Paying the amount of the bond to the Treasurer of the United States.

(ii) Obtaining a bond in the proper amount from a third party surety agent that is 

payable to satisfy U.S. administrative or judicial judgments against the foreign refiner, 
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provided EPA agrees in advance as to the third party and the nature of the surety

agreement.

(iii) An alternative commitment that results in assets of an appropriate liquidity and 

value being readily available to the United States, provided EPA agrees in advance as to 

the alternative commitment.

(3) If the bond amount for a foreign refinery increases, the foreign refiner shall 

increase the bond to cover the shortfall within 90 days of the date the bond amount 

changes. If the bond amount decreases, the foreign refiner may reduce the amount of the 

bond beginning 90 days after the date the bond amount changes.

(4) Bonds posted under this paragraph (k) shall–

(i) Be used to satisfy any judicial judgment that results from an administrative or 

judicial enforcement action for conduct in violation of this subpart O, including where 

such conduct violates 18 U.S.C. 1001 and Clean Air Act section 113(c)(2) (42 U.S.C. 

7413(c)(2));

(ii) Be provided by a corporate surety that is listed in the U.S. Department of 

Treasury Circular 570 “Companies Holding Certificates of Authority as Acceptable 

Sureties on Federal Bonds and Acceptable Reinsuring Companies” (Available from the 

U.S. Department of the Treasury, Financial Management Service, Surety Bond Branch, 

3700 East-West Highway, Room 6A04, Hyattsville, MD, 20782. Also available on the 

internet at http://www.fms.treas.gov/c570/c570.html); and

(iii) Include a commitment that the bond will remain in effect for at least five years 

following the end of latest averaging period that the foreign refiner produces gasoline 

pursuant to the requirements of this subpart O.

(5) On any occasion a foreign refiner bond is used to satisfy any judgment, the 

foreign refiner shall increase the bond to cover the amount used within 90 days of the 

date the bond is used.

(l) English language reports. Any report or other document submitted to EPA by any 

foreign refiner must be in English, or must include an English language translation.

(m) Prohibitions. (1) No person may combine Certified Sulfur-FRGAS with any NonCertified Sulfur-FRGAS or Non-Sulfur-FRGAS, and no person may combine Certified 

Sulfur-FRGAS with any Certified Sulfur-FRGAS produced at a different refinery, until 

the importer has met all the requirements of paragraph (n) of this section, except as 

provided in paragraph (e) of this section.

(2) No foreign refiner or other person may cause another person to commit an action 

prohibited in paragraph (m)(1) of this section, or that otherwise violates the requirements 

of this section.

(n) U.S. importer requirements. Any U.S. importer shall meet the following 

requirements:

(1) Each batch of imported gasoline shall be classified by the importer as being 

Sulfur-FRGAS or as Non-Sulfur-FRGAS, and each batch classified as Sulfur-FRGAS 

shall be further classified as Certified Sulfur-FRGAS or as Non-certified Sulfur-FRGAS.
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(2) Gasoline shall be classified as Certified Sulfur-FRGAS or as Non-Certified 

Sulfur-FRGAS according to the designation by the foreign refiner if this designation is 

supported by product transfer documents prepared by the foreign refiner as required in 

paragraph (d) of this section, unless the gasoline is classified as Non-Certified SulfurFRGAS under paragraph (g) of this section.

(3) For each gasoline batch classified as Sulfur-FRGAS, any U.S. importer shall 

perform the following procedures:

(i) In the case of both Certified and Non-Certified Sulfur-FRGAS, have an 

independent third party–

(A) Determine the volume of gasoline in the vessel.

(B) Use the foreign refiner’s Sulfur-FRGAS certification to determine the name and 

EPA-assigned registration number of the foreign refinery that produced the SulfurFRGAS.

(C) Determine the name and country of registration of the vessel used to transport the 

Sulfur-FRGAS to the United States.

(D) Determine the date and time the vessel arrives at the U.S. port of entry.

(ii) In the case of Certified Sulfur-FRGAS, have an independent third party–

(A) Collect a representative sample from each vessel compartment subsequent to the 

vessel’s arrival at the U.S. port of entry and prior to off loading any gasoline from the 

vessel.

(B) Prepare a volume-weighted vessel composite sample from the compartment 

samples.

(C) Determine the sulfur value using the methodologies specified in § 80.1630, by the 

third party analyzing the sample, or by the third party observing the importer analyzing 

the sample.

(4) Any importer shall submit reports within thirty days following the date any vessel 

transporting Sulfur-FRGAS arrives at the U.S. port of entry–

(i) To the Administrator containing the information determined under paragraph 

(n)(3) of this section; and

(ii) To the foreign refiner containing the information determined under paragraph 

(n)(3) of this section.

(5) Any U.S. importer shall meet the applicable requirements of this subpart O, 

including sulfur content standards specified in § 80.1603, for any imported gasoline that 

is not classified as Certified Sulfur-FRGAS under paragraph (n)(2) of this section.

(o) Truck imports of Certified Sulfur-FRGAS produced by a foreign small refiner or 

foreign small volume refinery. (1) Any refiner whose Certified Sulfur-FRGAS is 

transported into the United States by truck may petition EPA to use alternative 

procedures to meet all the following requirements:

(i) Certification under paragraph (d)(5) of this section.

(ii) Load port and port of entry sampling and testing under paragraphs (f) and (g) of 

this section.

(iii) Attest under paragraph (h) of this section.

(iv) Importer testing under paragraph (n)(3) of this section.
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(2) These alternative procedures must ensure Certified Sulfur-FRGAS remains 

segregated from Non-Certified Sulfur-FRGAS and from Non-Sulfur-FRGAS until it is 

imported into the United States. The petition will be evaluated based on whether it 

adequately addresses all the following:

(i) Provisions for monitoring pipeline shipments, if applicable, from the refinery, that 

ensure segregation of Certified Sulfur-FRGAS from that refinery from all other gasoline.

(ii) Contracts with any terminals and/or pipelines that receive and/or transport 

Certified Sulfur-FRGAS, that prohibit the commingling of such Certified Sulfur-FRGAS 

with any of the following:

(A) Other Certified Sulfur-FRGAS from other refineries.

(B) All Non-Certified Sulfur-FRGAS.

(C) All Non-Sulfur-FRGAS

(iii) Procedures for obtaining and reviewing truck loading records and U.S. import 

documents for Certified Sulfur-FRGAS to ensure that such gasoline is only loaded into 

trucks making deliveries to the United States.

(iv) Attest procedures to be conducted annually by an independent third party that 

review loading records and import documents based on volume reconciliation, or other 

criteria, to confirm that all Certified Sulfur-FRGAS remains segregated throughout the 

distribution system and is only loaded into trucks for import into the United States.

(3) The petition required by this section must be submitted to EPA along with the 

application for small refiner status or small volume refinery status under § 80.1622 and 

this section.

(p) Withdrawal or suspension of a foreign refinery’s small refiner or small volume 

refinery status approval. EPA may withdraw or suspend approval where any of the 

following occur:

(1) A foreign refiner fails to meet any requirement of this section.

(2) A foreign government fails to allow EPA inspections as provided in paragraph 

(i)(1) of this section.

(3) A foreign refiner asserts a claim of, or a right to claim, sovereign immunity in an 

action to enforce the requirements in this subpart O.

(4) A foreign refiner fails to pay a civil or criminal penalty that is not satisfied using

the foreign refiner bond specified in paragraph (k) of this section.

(q) [Reserved]

(r) Additional requirements for petitions, reports and certificates. Any petition for 

approval, any alternative procedures under paragraph (o) of this section, and any

certification under paragraph (d)(3) of this section shall be–

(1) Submitted in accordance with procedures specified by the Administrator, 

including use of any forms that may be specified by the Administrator; and

(2) Be signed by the president or owner of the foreign refiner company, or by that 

person’s immediate designee, and shall contain the following declaration:
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I hereby certify: (1) that I have actual authority to sign on behalf of and to bind [insert 

name of foreign refiner] with regard to all statements contained herein; (2) that I am 

aware that the information contained herein is being certified, or submitted to the United 

States Environmental Protection Agency, under the applicable requirements of 40 CFR 

Part 80, subparts H and O, and that the information is material for determining 

compliance under these regulations; and (3) that I have read and understand the 

information being certified or submitted, and this information is true, complete and 

correct to the best of my knowledge and belief after I have taken reasonable and 

appropriate steps to verify the accuracy thereof.

I affirm that I have read and understand the provisions of 40 CFR part 80, subpart O, 

including 40 CFR 80.1666 [insert name of foreign refiner]. Pursuant to Clean Air Act 

section 113(c) and 18 U.S.C. 1001, the penalty for furnishing false, incomplete or 

misleading information in this certification or submission is a fine of up to $10,000, 

and/or imprisonment for up to five years.

§ 80.1667 Attest engagement requirements. 

In addition to the requirements for attest engagements that apply to refiners and importers 

under §§ 80.125 through 80.130, 80.1666, and other sections of this part 80 the attest 

engagements for importers and refiners must include the following procedures and 

requirements each year.

(a) Refiners subject to national standards and Small Refiner and Small Volume 

Refinery Status. (1) If the refiner asserts small refinery status or small volume refinery

status for the refinery, obtain the EPA approval letter for the refinery to determine the 

refinery’s applicable annual average standard and credit generation status.

(2) Determine whether the refinery applied the correct annual average sulfur standard 

and whether it was eligible to generate credits and report the finding.

(3) If the annual average sulfur standard is incorrect or credit generation was 

inappropriate, recalculate compliance using the appropriate sulfur standard and using 

appropriate credits and report as a finding.

(b) EPA reports. (1) Obtain and read a copy of the refinery’s or importer’s annual 

sulfur reports filed with EPA for the year.

(2) Agree the yearly volume of gasoline reported to EPA in the sulfur reports with the 

inventory reconciliation analysis under the attest engagement provisions of § 80.128.

(3) Calculate the annual average sulfur level for all gasoline and agree that value with 

the value reported to EPA.

(4) Obtain and read a copy of the refinery’s or importer’s sulfur credit report.

(5) Agree the information in the refinery’s or importer’s batch reports filed with EPA 

under §§ 80.75 and 80.105, and any laboratory test results, with the information 

contained in the annual sulfur report required under § 80.1652.
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(c) Credit generation before 2017. In the case of a refinery that generates credits 

during 2014 through 2016–

(1) Obtain a written representation from the company representative stating the 

refinery produces gasoline from crude oil.

(2) Obtain the annual average sulfur level from paragraph (b)(3) of this section.

(3) Compute and report as a finding the total number of sulfur credits generated, and 

agree this value with the value reported to EPA.

(d) Credit generation in 2017 and thereafter. The following procedures shall be 

completed for a refinery or importer that generates credits in 2017 and thereafter:

(1) Obtain the annual average sulfur level for gasoline from paragraph (b)(3) of this 

section.

(2) If the sulfur value under paragraph (d)(1) of this section is less than 10 ppm, 

compute and report as a finding the difference between the sulfur level under paragraph 

(d)(1) of this section and 10 ppm.

(3) Compute and report as a finding the total number of sulfur credits generated, and 

agree this number with the number reported to EPA.

(e) Credit purchases and sales. The following attest procedures shall be completed 

for a refinery or importer that is a transferor or transferee of credits during an averaging 

period:

(1) Obtain contracts or other documents for all credits transferred to another refinery

or importer during the year being reviewed; compute and report as a finding the number 

and year of creation of credits represented in these documents as being transferred away; 

and agree with the report to EPA.

(2) Obtain contracts or other documents for all credits received during the year being 

reviewed; compute and report as a finding the number and year of creation of credits 

represented in these documents as being received; and agree with the report to EPA.

(f) Credit expiration. A refinery or importer that possesses credits during an 

averaging period must obtain a list of all credits in the refiner’s or importer’s possession 

at any time during the year being reviewed, identified by the year of creation of the 

credits.

(g) Credit reconciliation. The following attest procedures shall be completed each 

year credits were in the refiner’s or importer’s possession at any time during the year:

(1) Obtain the credits remaining or the credit deficit from the previous year from the 

refiner’s or importer’s report to EPA for the previous year.

(2) Compute and report as a finding the net credits remaining at the conclusion of the 

year being reviewed by totaling–

(i) Credits remaining from the previous year; plus

(ii) Credits generated under in an averaging period; plus

(iii) Credits purchased; minus
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(iv) Credits sold; minus

(v) Credits used; minus

(vi) Credits expiring; minus

(vii) Credit deficit from the previous year.

(3) Agree the credits remaining or the credit deficit at the conclusion of the year 

being reviewed with the report to EPA.

(4) If the refinery or importer had a credit deficit for both the previous year and the 

year being reviewed, report this fact as a finding.

PART 85— CONTROL OF AIR POLLUTION FROM MOBILE SOURCES

49. The authority citation for part 85 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart F—[Amended]

50. Section 85.510 is amended by revising paragraph (b)(9) to read as follows:

§ 85.510 Exemption provisions for new and relatively new vehicles/engines.

* * * * *

(b) * * *

(9) OBD requirements. (i) The OBD system must properly detect and identify 

malfunctions in all monitored emission-related powertrain systems or components 

including any new monitoring capability necessary to identify potential emission 

problems associated with the new fuel.

(ii) Conduct all OBD testing necessary to demonstrate compliance with 40 CFR 86.010-

18 or 86.1806-05.

(iii) Submit the applicable OBD reporting requirements set forth in 40 CFR part 86, 

subparts A and S, and submit the following statement of compliance if the OEM 

vehicles/engines were required to be OBD-equipped: 

The test group/engine family converted to an alternative fuel has fully functional OBD 

systems and therefore meets the OBD requirements specified in 40 CFR part 86 when 

operating on the alternative fuel.

* * * * *

51. Section 85.515 is amended by revising paragraph (b)(9)(iii) to read as follows:

§ 85.515 Exemption provisions for intermediate age vehicles/engines.

* * * * *

(b) * * *

(9) * * *

(iii) In addition to conducting OBD testing described in this paragraph (b)(9), you must 

submit to EPA the following statement of compliance if the OEM vehicles/engines were 

required to be OBD-equipped:

The test group/engine family converted to an alternative fuel has fully functional OBD 

systems and therefore meets the OBD requirements specified in 40 CFR part 86 when 

operating on the alternative fuel.

* * * * *
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52. Section 85.520 is amended by revising paragraph (b)(4)(iii) to read as follows:

§ 85.520 Exemption provisions for outside useful life vehicles/engines.

* * * * *

(b) * * *

(4) * * *

(iii) In addition to conducting OBD testing described in this paragraph (b)(4), you must 

submit to EPA the following statement of compliance if the OEM vehicles/engines were 

required to be OBD-equipped: 

The test group/engine family converted to an alternative fuel has fully functional OBD 

systems and therefore meets the OBD requirements specified in 40 CFR part 86 when 

operating on the alternative fuel.

* * * * *

Subpart P—[Amended]

53. Section 85.1515 is revised to read as follows:

§ 85.1515 Emission standards and test procedures applicable to imported 

nonconforming motor vehicles and motor vehicle engines.

(a) Notwithstanding any other requirements of this subpart, any motor vehicle or motor 

vehicle engine conditionally imported pursuant to § 85.1505 or § 85.1509 and required to 

be emission tested shall be tested using the FCT at 40 CFR part 86 applicable to current 

model year motor vehicles and motor vehicle engines at the time of testing or reduced 

testing requirements as follows:

(1) ICIs are eligible for reduced testing under this paragraph (a) subject to the following 

conditions:

(i) The OEM must have a valid certificate of conformity covering the vehicle.

(ii) The vehicle must be in its original configuration as certified by the OEM. This 

applies for all emission-related components, including the electronic control module, 

engine calibrations, and all evaporative/refueling control hardware. It also applies for 

OBD software and hardware, including all sensors and actuators. 

(iii) The vehicle modified as described in paragraph (a)(1)(ii) of this section must fully

comply with all applicable emission standards and requirements.

(iv) Vehicles must have the proper OBD systems installed and operating. When faults 

are present, the ICI must test and verify the system’s ability to find the faults (such as 

disconnected components), set codes, and illuminate the light, and set readiness codes as 

appropriate for each vehicle. When no fault is present, the ICI must verify that after 

sufficient prep driving (typically one FTP test cycle), all OBD readiness codes are set and 

the OBD system does not indicate a malfunction (i.e., no codes set and no light 

illuminated).

(v) The ICI may not modify more than 300 vehicles in any given model year using 

reduced testing provisions in this paragraph (a). 

(vi) The ICI must state in the application for certification that it will meet all the 

conditions in this paragraph (a)(1).

(2) The following provisions allow for ICIs to certify vehicles with reduced testing:
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(i) In addition to the test waivers specified in 40 CFR 86.1829, you may provide a 

statement in the application for certification, supported by engineering analysis, that 

vehicles comply with any of the following standards that apply instead of submitting test 

data:

(A) Cold temperature CO and NMHC emission standards specified in 40 CFR 86.1811.

(B) SFTP emission standards specified in 40 CFR 86.1811 and 86.1816 for all pollutants.

(C) For anything other than diesel-fueled vehicles, PM emission standards specified in 40 

CFR 86.1811 and 86.1816.

(D) Any running loss, refueling, spitback, bleed emissions, and leak standards specified 

in 40 CFR part 86, subparts A and S. 

(ii) You must perform testing and submit test data as follows to demonstrate compliance 

with emission standards:

(A) Exhaust and fuel economy tests. You must measure emissions over the FTP driving 

cycle and the highway fuel economy driving cycle as specified in 40 CFR 600.109 to 

meet the fuel economy requirements in 40 CFR part 600 and demonstrate compliance 

with the exhaust emission standards in 40 CFR part 86 (other than PM). Measure exhaust 

emissions and fuel economy with the same test procedures used by the original 

manufacturer to test the vehicle for certification. However, you must use an electric 

dynamometer meeting the requirements of § 86.108 or 40 CFR part 1066, subpart B, 

unless we approve a different dynamometer based on excessive compliance costs. If you 

certify based on testing with a different dynamometer, you must state in the application 

for certification that all vehicles in the emission family will comply with emission 

standards if tested on an electric dynamometer. 

(B) Evaporative emission test. You may measure evaporative emissions as specified in 

this paragraph (a)(2)(ii)(B) to demonstrate compliance with the evaporative emission 

standards in 40 CFR part 86 instead of the otherwise specified procedures. Use 

measurement equipment for evaporative measurements specified in 40 CFR part 86,

subpart B, except that the evaporative emission enclosure does not need to accommodate 

varying ambient temperatures. The evaporative measurement procedure is integral to the 

procedure for measuring exhaust emissions over the FTP driving cycle as described in 

paragraph (a)(ii)(2)(A) of this section. Perform canister preconditioning using the same 

procedure used by the original manufacturer to certify the vehicle; perform this canister 

loading before the initial preconditioning drive. Perform a diurnal emission test at the 

end of the stabilization period before the exhaust emission test by heating the fuel from 

60 to 84°F, either by exposing the vehicle to increasing ambient temperatures or by 

applying heat directly to the fuel tank. Measure hot soak emissions as described in 40 

CFR 86.138-96(k). We may approve alternative measurement procedures that are 

equivalent to or more stringent than the specified procedures if the specified procedures 

are impractical for particular vehicle models or measurement facilities. The sum of the 

measured diurnal and hot soak values must meet the appropriate emission standard as 

specified in this section. 

(b) The emission standards applicable to nonconforming light-duty vehicles and lightduty trucks imported pursuant to this subpart are outlined in tables 1 and 2 of this section, 
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respectively. The useful life as specified in tables 1 and 2 of this section is applicable to 

imported light-duty vehicles and light-duty trucks, respectively.

(c)(1) Nonconforming motor vehicles or motor vehicle engines of 1994 OP year and later 

conditionally imported pursuant to § 85.1505 or § 85.1509 shall meet all of the emission 

standards specified in 40 CFR part 86 for the OP year of the vehicle or motor vehicle 

engine. The useful life specified in 40 CFR part 86 for the OP year of the motor vehicle 

or motor vehicle engine is applicable where useful life is not designated in this subpart.

(2)(i) Nonconforming light-duty vehicles and light light-duty trucks (LDV/LLDTs) 

originally manufactured in OP years 2004, 2005 or 2006 must meet the FTP exhaust 

emission standards of bin 9 in Tables S04–1 and S04–2 in 40 CFR 86.1811–04 and the 

evaporative emission standards for light-duty vehicles and light light-duty trucks 

specified in 40 CFR 86.1811–01(e)(5).

(ii) Nonconforming LDT3s and LDT4s (HLDTs) and medium-duty passenger vehicles 

(MDPVs) originally manufactured in OP years 2004 through 2006 must meet the FTP 

exhaust emission standards of bin 10 in Tables S04–1 and S04–2 in 40 CFR 86.1811–04 

and the applicable evaporative emission standards specified in 40 CFR 86.1811–04(e)(5). 

For 2004 OP year HLDTs and MDPVs where modifications commence on the first 

vehicle of a test group before December 21, 2003, this requirement does not apply to the 

2004 OP year. ICIs opting to bring all of their 2004 OP year HLDTs and MDPVs into 

compliance with the exhaust emission standards of bin 10 in Tables S04–1 and S04–2 in 

40 CFR 86.1811–04, may use the optional higher NMOG values for their 2004–2006 OP 

year LDT2s and 2004–2008 LDT4s.

(iii) Nonconforming LDT3s and LDT4s (HLDTs) and medium-duty passenger vehicles 

(MDPVs) originally manufactured in OP years 2007 and 2008 must meet the FTP 

exhaust emission standards of bin 8 in Tables S04–1 and S04–2 in 40 CFR 86.1811–04 

and the applicable evaporative standards specified in 40 CFR 86.1811–04(e)(5).

(iv) Nonconforming LDV/LLDTs originally manufactured in OP years 2007 through 

2021 and nonconforming HLDTs and MDPVs originally manufactured in OP year 2009 

through 2021 must meet the FTP exhaust emission standards of bin 5 in Tables S04–1 

and S04–2 in 40 CFR 86.1811–04, and the evaporative standards specified in 40 CFR 

86.1811-04(e)(1) through (4).

(v) ICIs are exempt from the Tier 2 and the interim non-Tier2 phase-in intermediate 

percentage requirements for exhaust, evaporative, and refueling emissions described in 

40 CFR 86.1811–04.

(vi) In cases where multiple standards exist in a given model year in 40 CFR part 86 due 

to phase-in requirements of new standards, the applicable standards for motor vehicle 

engines required to be certified to engine-based standards are the least stringent standards 

applicable to the engine type for the OP year.

(vii) Nonconforming LDV/LLDTs originally manufactured in OP years 2009 through 

2021 must meet the evaporative emission standards in Table S09–1 in 40 CFR 86.1811–

09(e). However, LDV/LLDTs originally manufactured in OP years 2009 and 2010 and 

imported by ICIs who qualify as small-volume manufacturers as defined in 40 CFR 

86.1838–01 are exempt from the LDV/LLDT evaporative emission standards in Table 
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S09–1 in 40 CFR 86.1811–09(e), but must comply with the Tier 2 evaporative emission 

standards in Table S04–3 in 40 CFR 86.1811–04(e).

(viii) Nonconforming HLDTs and MDPVs originally manufactured in OP years 2010 

through 2021 must meet the evaporative emission standards in Table S09–1 in 40 CFR 

86.1811–09(e). However, HLDTs and MDPVs originally manufactured in OP years 2010 

and 2011 and imported by ICIs, who qualify as small-volume manufacturers as defined in 

40 CFR 86.1838–01, are exempt from the HLDTs and MDPVs evaporative emission 

standards in Table S09–1 in 40 CFR 86.1811–09(e), but must comply with the Tier 2 

evaporative emission standards in Table S04–3 in 40 CFR 86.1811–04(e).

(ix) Nonconforming LDVs, LDTs, MDPVs, and complete heavy-duty vehicles at or 

below 14,000 pounds GVWR originally manufactured in OP years 2022 and later must 

meet the Tier 3 exhaust and evaporative emission standards in 40 CFR 86.1811-17, 

86.1813-17, and 86.1816-18.

(3)(i) As an option to the requirements of paragraph (c)(2) of this section, independent 

commercial importers may elect to meet lower bins in Tables S04–1 and S04–2 of 40 

CFR 86.1811–04 than specified in paragraph (c)(2) of this section and bank or sell NOx 

credits as permitted in 40 CFR 86.1860–04 and 40 CFR 86.1861–04. An ICI may not 

meet higher bins in Tables S04–1 and S04–2 of 40 CFR 86.1811–04 than specified in 

paragraph (c)(2) of this section unless it demonstrates to the Administrator at the time of 

certification that it has obtained appropriate and sufficient NOx credits from another 

manufacturer, or has generated them in a previous model year or in the current model 

year and not transferred them to another manufacturer or used them to address other 

vehicles as permitted in 40 CFR 86.1860–04 and 40 CFR 86.1861–04.

(ii) Where an ICI desires to obtain a certificate of conformity using a bin higher than 

specified in paragraph (c)(2) of this section, but does not have sufficient credits to cover 

vehicles produced under such certificate, the Administrator may issue such certificate if 

the ICI has also obtained a certificate of conformity for vehicles certified using a bin 

lower than that required under paragraph (c)(2) of this section. The ICI may then produce 

vehicles to the higher bin only to the extent that it has generated sufficient credits from 

vehicles certified to the lower bin during the same model year.

(4) [Reserved]

(5) Except for the situation where an ICI desires to bank, sell or use NOx credits as 

described in paragraph (c)(3) of this section, the requirements of 40 CFR 86.1811–04 

related to fleet average NOx standards and requirements to comply with such standards 

do not apply to vehicles modified under this subpart.

(6) ICIs using bins higher than those specified in paragraph (c)(2) of this section must 

monitor their production so that they do not produce more vehicles certified to the 

standards of such bins than their available credits can cover. ICIs must not have a credit 

deficit at the end of a model year and are not permitted to use the deficit carryforward 

provisions provided in 40 CFR 86.1860–04(e).

(7) The Administrator may condition the certificates of conformity issued to ICIs as 

necessary to ensure that vehicles subject to paragraph (c) of this section comply with the 

appropriate average NOx standard for each model year.
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(8)(i) Nonconforming LDV/LLDTs originally manufactured in OP years 2010 and later 

must meet the cold temperature NHMC emission standards in Table S10–1 in 40 CFR 

86.1811–10(g).

(ii) Nonconforming HLDTs and MDPVs originally manufactured in OP years 2012 and 

later must meet the cold temperature NHMC emission standards in Table S10–1 in 40 

CFR 86.1811–10(g).

(iii) ICIs, which qualify as small-volume manufacturers, are exempt from the cold 

temperature NMHC phase-in intermediate percentage requirements described in 40 CFR 

86.1811–10(g)(3). See 40 CFR 86.1811–04(k)(5)(vi) and (vii).

(iv) As an alternative to the requirements of paragraphs (c)(8)(i) and (ii) of this section, 

ICIs may elect to meet a cold temperature NMHC family emission level below the cold 

temperature NMHC fleet average standards specified in Table S10–1 of 40 CFR 

86.1811–10 and bank or sell credits as permitted in 40 CFR 86.1864–10. An ICI may not 

meet a higher cold temperature NMHC family emission level than the fleet average 

standards in Table S10–1 of 40 CFR 86.1811–10 as specified in paragraphs (c)(8)(i) and 

(ii) of this section, unless it demonstrates to the Administrator at the time of certification 

that it has obtained appropriate and sufficient NMHC credits from another manufacturer, 

or has generated them in a previous model year or in the current model year and not 

traded them to another manufacturer or used them to address other vehicles as permitted 

in 40 CFR 86.1864–10.

(v) Where an ICI desires to obtain a certificate of conformity using a higher cold 

temperature NMHC family emission level than specified in paragraphs (c)(8)(i) and (ii) 

of this section, but does not have sufficient credits to cover vehicles imported under such 

certificate, the Administrator may issue such certificate if the ICI has also obtained a 

certificate of conformity for vehicles certified using a cold temperature NMHC family

emission level lower than that required under paragraphs (c)(8)(i) and (ii) of this section. 

The ICI may then import vehicles to the higher cold temperature NMHC family emission 

level only to the extent that it has generated sufficient credits from vehicles certified to a 

family emission level lower than the cold temperature NMHC fleet average standard 

during the same model year.

(vi) ICIs using cold temperature NMHC family emission levels higher than the cold 

temperature NMHC fleet average standards specified in paragraphs (c)(8)(i) and (ii) of 

this section must monitor their imports so that they do not import more vehicles certified 

to such family emission levels than their available credits can cover. ICIs must not have a 

credit deficit at the end of a model year and are not permitted to use the deficit 

carryforward provisions provided in 40 CFR 86.1864–10.

(vii) The Administrator may condition the certificates of conformity issued to ICIs as 

necessary to ensure that vehicles subject to this paragraph (c)(8) comply with the 

applicable cold temperature NMHC fleet average standard for each model year.

(d) Except as provided in paragraph (c) of this section, ICI's must not participate in 

emission-related programs for emissions averaging, banking and trading, or 

nonconformance penalties.
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Table 1 to § 85.1515—Emission Standards Applicable to Imported Light-Duty Motor 

Vehicles1,2,3

OP Year Hydrocarbon Carbon

monoxide

Oxides of 

nitrogen

Diesel 

Particulate

Evaporative 

hydrocarbon

Useful life 

(years/miles)

1968–

1976

1.5 gpm 15 gpm 3.1 gpm 6.0 g/test 5/50,000

1977–

1979

1.5 gpm 15 gpm 2.0 gpm 6.0 g/test 5/50,000

1980 0.41 gpm 7.0 gpm 2.0 gpm 6.0 g/test 5/50,000

1981 0.41 gpm 3.4 gpm 1.0 gpm 2.0 g/test 5/50,000

1982–

1986

0.41 gpm 3.4 gpm 1.0 gpm 0.60 gpm 2.0 g/test 5/50,000

1987–

1993

0.41 gpm 3.4 gpm 1.0 gpm 0.20 gpm 2.0 g/test 5/50,000

1994 and 

later

(

4

) (

4

) (

4

) (

4

) (

4

) (

4

)

1Diesel particulate standards apply only to diesel fueled light-duty vehicles. Evaporative hydrocarbon 

standards apply only to non-diesel fueled light-duty vehicles. For alternative fueled light-duty vehicles, the 

evaporative hydrocarbon standard is interpreted as organic material hydrocarbon equivalent grams carbon 

per test, as applicable.

2No crankcase emissions shall be discharged into the ambient atmosphere from any non-diesel fueled lightduty vehicle.

3All light-duty vehicles shall meet the applicable emission standards at both low and high-altitudes 

according to the procedures specified in 40 CFR part 86 for current model year motor vehicles at the time 

of testing.

4

Specified in 40 CFR part 86 for the OP year of the vehicle, as described in paragraph (c) of this section.
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Table 2 to § 85.1515—Emission Standards Applicable to Imported Light-Duty

Trucks1,2,3,4,5

OP year Hydrocarbon Carbon 

monoxide

Oxides 

of 

nitrogen

Diesel 

Particulate

Evaporative 

hydrocarbon

Useful life 

(years/miles)

1968–78 2.0 gpm 20 gpm 3.1 gpm 6.0 g/test 5/50,000

1979–80 1.7 gpm 18 gpm 2.3 gpm 6.0 g/test 5/50,000

1981 1.7 gpm 18 gpm 2.3 gpm 2.0 g/test 5/50,000

1982–1983 1.7 gpm

(2.0)

18 gpm

(26)

2.3 gpm

(2.3)

0.60 gpm

(0.60)

2.0 g/test

(2.6)

5/50,000

1984 0.80 gpm

(1.0)

10 gpm

(14)

2.3 gpm

(2.3)

0.60 gpm

(0.60)

2.0 g/test

(2.6)

5/50,000

1985–1986 0.80 gpm

(1.0)

10 gpm

(14)

2.3 gpm

(2.3)

0.60 gpm

(0.60)

2.0 g/test

(2.6)

11/120,000

1987 0.80 gpm

(1.0)

10 gpm

(14)

2.3 gpm

(2.3)

0.26 gpm

(0.26)

2.0 g/test

(2.6)

11/120,000

1988–1989 0.80 gpm

(1.0)

10 gpm

(14)

1.2 gpm6

(1.2)

0.26 gpm7

(2.0)

2.0 g/test

(2.6)

11/120,000

 1988–1989 0.80 gpm

(1.0)

10 gpm

(14)

1.7 gpm6

(1.7)

0.45 gpm7

(0.26)

2.0 g/test

(2.6)

11/120,000

 1988–1989 0.80 gpm

(1.0)

10 gpm

(14)

2.3 gpm6

(2.3)

0.45 gpm7

(0.26)

2.0 g/test

(2.6)

11/120,000

1990–1993 0.80 gpm

(1.0)

10 gpm

(14)

1.2 gpm8

(1.2)

0.26 gpm7

(0.26)

2.0 g/test

(2.6)

11/120,000

 1990–1993 0.80 gpm

(1.0)

10 gpm

(14)

1.7 gpm8

(1.7)

0.45 gpm7

(0.26)

2.0 g/test

(2.6)

11/120,000

1994 and later (

9

) (

9

) (

9

) (

9

) (

9

) (

9

)

1Diesel particulate standards apply only to diesel fueled light-duty trucks. Evaporative hydrocarbon 

standards apply only to non-diesel fueled light-duty trucks. For alternative fueled light-duty trucks, the 

evaporative hydrocarbon standard is interpreted as organic material hydrocarbon equivalent grams carbon 

per test, as applicable.

2No crankcase emissions shall be discharged into the ambient atmosphere from any non-diesel fueled lightduty truck.

3A carbon monoxide standard of 0.50% of exhaust flow at curb idle is applicable to all 1984 and later 

model year light-duty trucks sold to, or owned by, an importer for principal use at other than a designated 

high-altitude location. This requirement is effective for light-duty trucks sold to, or owned by an importer 

for principal use at a designated high-altitude location beginning with the 1988 model year.

4All 1982 OP year and later light-duty trucks sold to, or owned by, an importer for principal use at a 

designated high-altitude location shall meet high-altitude emission standards according to the requirements 

specified in 40 CFR part 86 for current model year light-duty trucks at the time of testing.

5

Standards in parentheses apply to motor vehicles sold to, or owned by, an importer for principal use at a 

designated high-altitude location. These standards must be met at high-altitude according to the procedures 

specified in 40 CFR part 86 for current model year motor vehicles at the time of testing.

6The oxides of nitrogen standard of 1.2 gpm applies to light-duty trucks at or below 3,750 pounds loaded 

vehicle weight and at or below 6,000 pounds GVWR. The 1.7 gpm standard applies to light-duty trucks 

above 3,750 pound loaded vehicle weight and at or below 6,000 pounds GVWR; the 2.3 gpm standard 

applies to light-duty trucks above 6,000 pounds GVWR.

7The diesel particulate standard of 0.26 gpm applies to light-duty trucks at or below 3,750 pounds loaded 

vehicle weight; the 0.45 gpm standard applies to light-duty trucks above 3,750 pounds loaded vehicle 

weight.

8The NOx standard of 1.2 gpm applies to light-duty trucks at or below 3,750 pounds loaded vehicle weight; 

the 1.7 gpm standard applies to light-duty trucks above 3,750 pounds loaded vehicle weight.
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 653 of 1039

9

Specified in 40 CFR part 86 for the OP year of the vehicle, as described in paragraph (c) of this section.

54. Subpart W, is revised to consist of §§ 85.2201, 85.2207, 85.2222, 85.2223, and 

85.2231, to read as follows:

Subpart W—Emission Control System Performance Warranty Short Tests

Sec.

85.2201 Applicability. 

85.2207 Onboard diagnostic test standards.

85.2222 Onboard diagnostic test procedures.

85.2223 Onboard diagnostic test report.

85.2231 Onboard diagnostic test equipment requirements.

Subpart W—Emission Control System Performance Warranty Short Tests

§ 85.2201 Applicability. 

(a) This subpart describes the test provisions to be employed in conjunction with the 

Emissions Performance Warranty in subpart V of this part. These provisions generally 

rely on a vehicle’s onboard diagnostic system (OBD) to indicate whether a vehicle passes 

or fails the test.

(b) The provisions of this subpart may be used to establish warranty eligibility for lightduty vehicles, light-duty trucks, and medium-duty passenger vehicles when tested during 

the useful life as prescribed in subpart V of this part.

§ 85.2207 Onboard diagnostic test standards.

(a) A vehicle shall fail the OBD test if it is a 1996 or newer vehicle and the vehicle 

connector is missing, has been tampered with, or is otherwise inoperable.

(b) A vehicle shall fail the OBD test if the malfunction indicator light (MIL) is 

commanded to be illuminated and it is not visually illuminated according to visual 

inspection.

(c) A vehicle shall fail the OBD test if the MIL is commanded to be illuminated for one 

or more diagnostic trouble codes (DTCs), as described in 40 CFR 86.1806. 

§ 85.2222 Onboard diagnostic test procedures.

The test sequence for the OBD inspection shall consist of the following steps:

(a) The OBD inspection shall be conducted with the key-on/engine running, with the 

exception of inspecting for MIL illumination as required in paragraph (d)(4) of this 

section, during which the inspection shall be conducted with the key-on/engine off.

(b) The inspector shall locate the vehicle connector and plug the test system into the 

connector.

(c) The test system shall send a Mode $01, PID $01 request in accordance with 40 CFR 

86.1806 to determine the OBD evaluation status. The test system shall determine what 

monitors are supported by the OBD system, and perform the readiness evaluation for 

applicable monitors in accordance with the requirements and specifications in 40 CFR 

86.1806.
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 654 of 1039

(1) Coincident with the beginning of mandatory testing, repair, and retesting based upon 

the OBD test, if the readiness evaluation indicates that any onboard tests are not 

complete, the customer shall be instructed to return after the vehicle has been run under 

conditions that allow completion of all applicable onboard tests. If the readiness 

evaluation again indicates that any onboard test is not complete, the vehicle shall be 

failed.

(2) An exception to paragraph (c)(1) of this section is allowed for MY 1996 to MY 2000 

vehicles, inclusive, with two or fewer unset readiness monitors, and for MY 2001 and 

newer vehicles with no more than one unset readiness monitor. Vehicles from those 

model years which would otherwise pass the OBD inspection, but for the unset readiness 

code in question, may be issued a passing certificate without being required to operate the 

vehicle in such a way as to activate those particular monitors. Vehicles from those model 

years with an unset readiness code that also have a DTC stored resulting in an illuminated 

MIL must be failed, though setting the unset readiness flag in question shall not be a 

prerequisite for passing the retest.

(d) The test system shall evaluate the MIL status bit and record status information in the 

vehicle test record.

(1) If the MIL status bit indicates that the MIL has been commanded to be illuminated, 

the test system shall send a Mode $03 request in accordance with 40 CFR 86.1806 to 

determine the stored DTCs. The system shall repeat this cycle until the number of codes 

reported equals the number expected based on the Mode $01 response. All DTCs 

resulting in MIL illumination shall be recorded in the vehicle test record and the vehicle 

shall fail the OBD inspection.

(2) If the MIL bit is not commanded to be illuminated the vehicle shall pass the OBD 

inspection, even if DTCs are present.

(3) If the MIL bit is commanded to be illuminated, the inspector shall visually inspect the 

MIL to determine if it is illuminated. If the MIL is commanded to be illuminated but is 

not, the vehicle shall fail the OBD inspection.

(4) If the MIL does not illuminate at all when the vehicle is in the key-on/engine-off 

condition, the vehicle shall fail the OBD inspection, even if no DTCs are present and the 

MIL has not been commanded on.

§ 85.2223 Onboard diagnostic test report.

(a) Motorists whose vehicles fail the OBD test described in § 85.2222 shall be provided 

with the OBD test results, including the codes retrieved, the name of the component or 

system associated with each DTC, the status of the MIL illumination command, and the 

customer alert statement as stated in paragraph (b) of this section.

(b) In addition to any codes that were retrieved, the test report shall include the following 

language:

Your vehicle's computerized self-diagnostic system (OBD) registered the faults listed below. The 

faults are probably an indication of a malfunction of an emission component. However, multiple 

and/or seemingly unrelated faults may be an indication of an emission-related problem that 

occurred previously, but upon further evaluation by the OBD system was determined to be only 

temporary. Therefore, proper diagnosis by a qualified technician is required to positively identify 

the source of any emission-related problem.
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 655 of 1039

§ 85.2231 Onboard diagnostic test equipment requirements.

(a) The test system interface to the vehicle shall include a plug that conforms to the 

requirements and specifications of 40 CFR 86.1806. 

(b) The test system shall be capable of communicating with the standard data link 

connector of vehicles with certified OBD systems.

(c) The test system shall be capable of checking for OBD monitors and the evaluation 

status of supported monitors (test complete/test not complete) in Mode $01 PID $01, as 

well as be able to request the DTCs, consistent with the requirements and specifications 

of 40 CFR 86.1806. 

Part 86— CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY 

VEHICLES AND ENGINES

55. The authority citation for part 86 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

56. Section 86.1 is revised to read as follows:

§ 86.1 Incorporation by reference.

(a) Certain material is incorporated by reference into this part with the approval of the 

Director of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. To enforce any 

edition other than that specified in this section, a document must be published in the 

Federal Register and the material must be available to the public. All approved material 

is available for inspection at U.S. EPA, Air and Radiation Docket and Information 

Center, 1301 Constitution Ave., NW., Room B102, EPA West Building, Washington, 

DC 20460, (202) 202-1744, and is available from the sources listed below. It is also 

available for inspection at the National Archives and Records Administration (NARA). 

For information on the availability of this material at NARA, call 202–741–6030, or go to 

http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html

.

(b) ASTM International material. The following standards are available from ASTM 

International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA, 19428-

2959, (610) 832-9585, or http://www.astm.org/:

(1) ASTM C1549-09, Standard Test Method for Determination of Solar Reflectance Near 

Ambient Temperature Using a Portable Solar Reflectometer, approved August 1, 2009, 

IBR approved for § 86.1869-12(b).

(2) ASTM D86-12, Standard Test Method for Distillation of Petroleum Products at 

Atmospheric Pressure, approved December 1, 2012, IBR approved for §§ 86.113-04(a), 

86.113-94(b), 86.213(a), and 86.513(a).

(3) ASTM D93-13, Standard Test Methods for Flash Point by Pensky- Martens Closed 

Cup Tester, approved July 15, 2013, IBR approved for § 86.113-94(b).

(4) ASTM D445-12, Standard Test Method for Kinematic Viscosity of Transparent and 

Opaque Liquids (and Calculation of Dynamic Viscosity), approved April 15, 2012, IBR 

approved for § 86.113-94(b).
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 656 of 1039

(5) ASTM D613-13, Standard Test Method for Cetane Number of Diesel Fuel Oil, 

approved December 1, 2013, IBR approved for § 86.113-94(b).

(6) ASTM D975-13a, Standard Specification for Diesel Fuel Oils, approved December 1, 

2013, IBR approved for § 86.1910(c).

(7) ASTM D976-06 (Reapproved 2011), Standard Test Method for Calculated Cetane 

Index of Distillate Fuels, approved October 1, 2011, IBR approved for § 86.113-94(b).

(8) ASTM D1319-13, Standard Test Method for Hydrocarbon Types in Liquid Petroleum 

Products by Fluorescent Indicator Adsorption, approved May 1, 2013, IBR approved for 

§§ 86.113-04(a), 86.213(a), and 86.513(a).

(9) ASTM D1945-03 (reapproved 2010), Standard Test Method for Analysis of Natural 

Gas by Gas Chromatography, approved January 1, 2010, IBR approved for §§ 86.113-

94(e) and 86.513(d).

(10) ASTM D2163-07, Standard Test Method for Determination of Hydrocarbons in 

Liquefied Petroleum (LP) Gases and Propane/Propene Mixtures by Gas Chromatography, 

approved December 1, 2007, IBR approved for §§ 86.113-94(f).

(11) ASTM D2622-10, Standard Test Method for Sulfur in Petroleum Products by

Wavelength Dispersive X-ray Fluorescence Spectrometry, approved February 15, 2010, 

IBR approved for §§ 86.113-04(a), 86.113-94(b), 86.213(a), and 86.513(a).

(12) ASTM D2699-13b, Standard Test Method for Research Octane Number of SparkIgnition Engine Fuel, approved October 1, 2013, IBR approved for §§ 86.113-04(a) and 

86.213(a).

(13) ASTM D2700-13b, Standard Test Method for Motor Octane Number of SparkIgnition Engine Fuel, approved October 1, 2013, IBR approved for §§ 86.113-04(a) and 

86.213(a).

(14) ASTM D3231-13, Standard Test Method for Phosphorus in Gasoline, approved June 

15, 2013, IBR approved for §§ 86.113-04(a), 86.213(a), and 86.513(a).

(15) ASTM D3237-12, Standard Test Method for Lead in Gasoline By Atomic 

Absorption Spectroscopy, approved June 1, 2012, IBR approved for §§ 86.113-04(a), 

86.213(a), and 86.513(a). 

(16) ASTM D4052-11, Standard Test Method for Density, Relative Density, and API 

Gravity of Liquids by Digital Density Meter, approved October 15, 2011, IBR approved 

for § 86.113-94(b).

(17) ASTM D5186-03 (Reapproved 2009), Standard Test Method for Determination of 

the Aromatic Content and Polynuclear Aromatic Content of Diesel Fuels and Aviation 

Turbine Fuels By Supercritical Fluid Chromatography, approved April 15, 2009, IBR 

approved for § 86.113-94(b).

(18) ASTM D5191-13, Standard Test Method for Vapor Pressure of Petroleum Products 

(Mini Method), approved December 1, 2013, IBR approved for §§ 86.113-04(a), 

86.213(a), and 86.513(a).

(19) ASTM E29-93a, Standard Practice for Using Significant Digits in Test Data to 

Determine Conformance with Specifications, approved March 15, 1993, IBR approved 

for §§ 86.004-15(c), 86.007-11(a), 86.007-15(m), 86.1803-01, 86.1823-01(a), 86.1824-

01(c), 86.1825-01(c).
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 657 of 1039

(20) ASTM E903-96, Standard Test Method for Solar Absorptance, Reflectance, and 

Transmittance of Materials Using Integrating Spheres, approved April 10, 1996, IBR 

approved for § 86.1869-12(b).

(21) ASTM E1918-06, Standard Test Method for Measuring Solar Reflectance of 

Horizontal and Low-Sloped Surfaces in the Field, approved August 15, 2006, IBR 

approved for § 86.1869-12(b).

(c) ANSI material. The following standards are available from American National 

Standards Institute, 25 W 43rd Street, 4th Floor, New York, NY 10036, (212) 642-4900, 

or http://www.ansi.org:

(1) ANSI NGV1-2006, Standard for Compressed Natural Gas Vehicle (NGV) Fueling 

Connection Devices, 2nd edition, reaffirmed and consolidated March 2, 2006, IBR 

approved for § 86.1813-17(f).

(2) [Reserved]

(d) California Air Resources Board. The following documents are available from the 

California Air Resources Board, 1001 I Street, Sacramento, CA, 95812, (916) 322–2884, 

or http://www.arb.ca.gov:

(1) California Requirements Applicable to the LEV III Program, including the following 

documents:

(i) LEV III exhaust emission standards are in Title 13 Motor Vehicles, Division 3 Air 

Resources Board, Chapter 1 Motor Vehicle Pollution Control Devices, Article 2 

Approval of Motor Vehicle Pollution Control Devices (New Vehicles), §1961.2 Exhaust 

Emission Standards and Test Procedures – 2015 and Subsequent Model Passenger Cars, 

Light-Duty Trucks, and Medium-Duty Vehicles, effective as of December 31, 2012, IBR 

approved for § 86.1803-01.

(ii) LEV III evaporative emission standards for model year 2015 and later vehicles are in 

Title 13 Motor Vehicles, Division 3 Air Resources Board, Chapter 1 Motor Vehicle 

Pollution Control Devices, Article 2 Approval of Motor Vehicle Pollution Control 

Devices (New Vehicles) §1976 Standards and Test Procedures for Motor Vehicle Fuel 

Evaporative Emissions, effective as of December 31, 2012, IBR approved for § 86.1803-

01.

(2) California Regulatory Requirements Applicable to the National Low Emission 

Vehicle Program, October 1996, IBR approved for § 86.113–04(a).

(3) California Regulatory Requirements known as Onboard Diagnostics II (OBD–II), 

Approved on April 21, 2003, Title 13, California Code of Regulations, Section 1968.2, 

Malfunction and Diagnostic System Requirements for 2004 and Subsequent Model-Year 

Passenger Cars, Light-Duty Trucks, and Medium-Duty Vehicles and Engines (OBD–II), 

IBR approved for § 86.1806–05(j).

(4) California Regulatory Requirements known as Onboard Diagnostics II (OBD–II), 

Approved on November 9, 2007, Title 13, California Code of Regulations, Section 

1968.2, Malfunction and Diagnostic System Requirements for 2004 and Subsequent 

Model-Year Passenger Cars, Light-Duty Trucks, and Medium-Duty Vehicles and 

Engines (OBD–II), IBR approved for § 86.1806–05(j).

(5) California Regulatory Requirements known as Onboard Diagnostics II (OBD-II), 

Title 13, Motor Vehicles, Division 3, Air Resources Board, Chapter 1, Motor Vehicle 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 658 of 1039

Pollution Control Devices, Article 2, Approval of Motor Vehicle Pollution Control 

Devices (New Vehicles), §1968.2 Malfunction and Diagnostic System Requirements –

2004 and Subsequent Model-Year Passenger Cars, Light-Duty Trucks, and Medium-Duty

Vehicles and Engines, effective as of July 31, 2013, IBR approved for § 86.1806-17(a).

(e) ISO material. The following standards are available from International Organization 

for Standardization, Case Postale 56, CH-1211 Geneva 20, Switzerland, 41-22-749-01-

11, or http://www.iso.org:

(1) ISO 13837:2008(E), Road Vehicles—Safety glazing materials—Method for the 

determination of solar transmittance, First edition, April 15, 2008, IBR approved for 

§ 86.1869-12(b).

(2) ISO 15765-4:2005(E), Road Vehicles—Diagnostics on Controller Area Networks 

(CAN)—Part 4: Requirements for emissions-related systems, January 15, 2005, IBR 

approved for §§ 86.010-18(k) and 86.1806-05(h).

(f) NIST material. The following documents are available from National Institute of 

Standards and Technology, 100 Bureau Drive, Gaithersburg, MD, 20899, or 

http://www.nist.gov:

(1) NIST Special Publication 811, 2008 Edition, Guide for the Use of the International 

System of Units (SI), March 2008, IBR approved for § 86.1901(d).

(2) [Reserved]

(g) SAE International material. The following standards are available from SAE 

International, 400 Commonwealth Dr., Warrendale, PA 15096-0001, (877) 606-7323 

(U.S. and Canada) or (724) 776-4970 (outside the U.S. and Canada), or 

http://www.sae.org:

(1) SAE J1151, Methane Measurement Using Gas Chromatography, stabilized September 

2011, IBR approved for § 86.111-94(b).

(2) SAE J1349, Engine Power Test Code—Spark Ignition and Compression Ignition—As 

Installed Net Power Rating, revised September 2011, IBR approved for § 86.1803-01.

(3) SAE J1850, Class B Data Communication Network Interface, Revised May 2001, 

IBR approved for § 86.1806-05(h).

(4) SAE J1877, Recommended Practice for Bar-Coded Vehicle Identification Number 

Label, July 1994, IBR approved for § 86.095-35(i).

(5) SAE J1892, Recommended Practice for Bar-Coded Vehicle Emission Configuration 

Label, October 1993, IBR approved for § 86.095-35(i).

(6) SAE J1930, Electrical/Electronic Systems Diagnostic Terms, Definitions, 

Abbreviations, and Acronyms, Revised May 1998, IBR approved for §§ 86.1808-01(f), 

86.1808-07(f).

(7) SAE J1930, Electrical/Electronic Systems Diagnostic Terms, Definitions, 

Abbreviations, and Acronyms—Equivalent to ISO/TR 15031-2: April 30, 2002, Revised 

April 2002, IBR approved for §§ 86.010-18(k) and 86.1806-05(h).

(8) SAE J1939, Recommended Practice for a Serial Control and Communications 

Vehicle Network, Revised October 2007, IBR approved for § 86.010-18(k).

(9) SAE J1939-11, Physical Layer—250K bits/s, Shielded Twisted Pair, Revised October 

1999, IBR approved for § 86.1806-05(h).
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 659 of 1039

(10) SAE J1939-13, Off-Board Diagnostic Connector, July 1999, IBR approved for 

§ 86.1806-05(h).

(11) SAE J1939-13, Off-Board Diagnostic Connector, Revised March 2004, IBR 

approved for § 86.010-18(k).

(12) SAE J1939-21, Data Link Layer, Revised April 2001, IBR approved for § 86.1806-

05(h).

(13) SAE J1939-31, Network Layer, Revised December 1997, IBR approved for 

§ 86.1806-05(h).

(14) SAE J1939-71, Vehicle Application Layer (Through February 2007), Revised 

January 2008, IBR approved for §§ 86.010-38(j) and 86.1806-05(h).

(15) SAE J1939-73, Application Layer—Diagnostics, Revised September 2006, IBR 

approved for §§ 86.010-18(k), 86.010-38(j), and 86.1806-05(h).

(16) SAE J1939-81, Network Management, Revised May 2003, IBR approved for 

§§ 86.010-38(j) and 86.1806-05(h).

(17) SAE J1962, Diagnostic Connector Equivalent to ISO/DIS 15031-3; December 14, 

2001, Revised April 2002, IBR approved for §§ 86.010-18(k) and 86.1806-05(h).

(18) SAE J1978, OBD II Scan Tool—Equivalent to ISO/DIS 15031-4; December 14, 

2001, Revised April 2002, IBR approved for §§ 86.010-18(k) and 86.1806-05(h).

(19) SAE J1979, E/E Diagnostic Test Modes, Revised September 1997, IBR approved 

for §§ 86.1808-01(f) and 86.1808-07(f).

(20) SAE J1979, (R) E/E Diagnostic Test Modes, Revised May 2007, IBR approved for 

§§ 86.010-18(k) and 86.1806-05(h).

(21) SAE J2012, (R) Diagnostic Trouble Code Definitions Equivalent to ISO/DIS 15031-

6: April 30, 2002, Revised April 2002, IBR approved for §§ 86.010-18(k) and 86.1806-

05(h).

(22) SAE J2064 FEB2011, R134a Refrigerant Automotive Air-Conditioned Hose, 

Revised February 2011, IBR approved for § 86.1867-12(a) and (b).

(23) SAE J2284-3, High Speed CAN (HSC) for Vehicle Applications at 500 KBPS, May

2001, IBR approved for §§ 86.1808-01(f) and 86.1808-07(f).

(24) SAE J2403, Medium/Heavy-Duty E/E Systems Diagnosis Nomenclature—Truck 

and Bus, Revised August 2007, IBR approved for §§ 86.010-18(k), 86.010-38(j), and 

86.1806-05(h).

(25) SAE J2534, Recommended Practice for Pass-Thru Vehicle Programming, February

2002, IBR approved for §§ 86.1808-01(f) and 86.1808-07(f).

(26) SAE J2727 FEB2012, Mobile Air Conditioning System Refrigerant Emission Charts 

for R-134a and R-1234yf, Revised February 2012, IBR approved for § 86.1867-12(a) and 

(b).

(27) SAE J2765 OCT2008, Procedure for Measuring System COP [Coefficient of 

Performance] of a Mobile Air Conditioning System on a Test Bench, issued October 

2008, IBR approved for § 86.1868-12(h).

(h) Truck and Maintenance Council material. The following documents are available 

from the Truck and Maintenance Council, 950 North Glebe Road, Suite 210, Arlington, 

VA 22203-4181, or (703) 838-1754:
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 660 of 1039

(1) TMC RP 1210B, Revised June 2007, WINDOWSTMCOMMUNICATION API, IBR 

approved for § 86.010-38(j).

(2) [Reserved]

Subpart A—[Amended]

57. Section 86.000-7 is amended as follows:

a. By revising the introductory text.

b. By removing and reserving paragraph (h)(1).

c. By revising paragraph (h)(6).

d. By removing paragraph (h)(7).

§ 86.000-7 Maintenance of records; submittal of information; right of entry.

Section 86.000–7 includes text that specifies requirements that differ from § 86.091–7 or 

§ 86.094–7. Where a paragraph in § 86.091–7 or § 86.094–7 is identical and applicable to 

§ 86.000–7, this may be indicated by specifying the corresponding paragraph and the 

statement “[Reserved]. For guidance see § 86.091–7.” or “[Reserved]. For guidance see § 

86.094–7.”

* * * * *

(h) * * *

(6) EPA may void ab initio a certificate for a vehicle certified to Tier 1 certification 

standards or to the respective evaporative and/or refueling test procedure and 

accompanying evaporative and/or refueling standards as set forth or otherwise referenced 

in § 86.098–10 for which the manufacturer fails to retain the records required in this 

section or to provide such information to the Administrator upon request.

§§ 86.000-8, 86.000-9, 86.000-16 [Removed]

58. Remove §§ 86.000-8, 86.000-9, and 86.000-16.

§ 86.000-24—[Amended]

59. Section 86.000-24 is amended as follows:

a. By removing the introductory text.

b. By removing and reserving paragraphs (a), (b)(1) introductory text, and (b)(1)(iii) 

through (f).

c. By removing and reserving paragraphs (g)(1) and (g)(2).

d. By removing paragraph (h).

§§ 86.000-26, 86.000-28, 86.001-9, 86.001-22 [Removed]

60. Remove §§ 86.000-26, 86.000-28, 86.001-9, and 86.001-22.

61. Section 86.001-23 is amended by revising the introductory text and adding a heading 

to paragraph (c) and removing and reserving paragraphs (c)(1), (f), and (g) to read as 

follows:

§ 86.001-23 Required data.
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 661 of 1039

Section 86.001–23 includes text that specifies requirements that differ from § 86.098–23. 

Where a paragraph in § 86.098–23 is identical and applicable to § 86.001–23, this may be 

indicated by specifying the corresponding paragraph and the statement “[Reserved]. For 

guidance see § 86.098–23.”

* * * * *

(c) Emission data —

* * * * *

§§ 86.001-25, 86.001-26, 86.001-28, 86.001-30, 86.004-9 [Removed]

62. Remove §§ 86.001-25, 86.001-26, 86.001-28, 86.001-30, and 86.004-9.

63. Section 86.004-11 is amended by revising paragraphs (b)(3) introductory text and 

(b)(4) introductory text and adding paragraph (b)(4)(iv) to read as follows:

§ 86.004-11 Emission standards for 2004 and later model year diesel heavy-duty 

engines and vehicles.

* * * * *

(b) * * *

(3) This paragraph (b)(3) applies as specified in 40 CFR 1037.103. Evaporative 

emissions (total of non-oxygenated hydrocarbons plus methanol) from heavy-duty 

vehicles equipped with methanol-fueled diesel engines shall not exceed the following 

standards. The standards apply equally to certification and in-use vehicles. The spitback 

standard also applies to newly assembled vehicles.

* * * * *

(4) This paragraph (b)(4) applies as specified in 40 CFR 1037.103. Evaporative 

emissions from 2004 and later model year heavy-duty vehicles equipped with natural gasfueled or liquefied petroleum gas-fueled HDEs shall not exceed the following standards. 

The standards apply equally to certification and in-use vehicles.

* * * * *

(iv) Compressed natural gas vehicles must meet the requirements for fueling connection 

devices as specified in § 86.1813-17(f)(1). Vehicles meeting these requirements are 

deemed to comply with evaporative emission standards.

* * * * *

64. Section 86.004-21 is amended as follows:

a. By revising the introductory text

b. By removing and reserving paragraph (b)(4)(i).

c. By removing paragraph (b)(5)(v).

d. By removing and reserving paragraphs (k) and (l).

§ 86.004-21 Application for certification.

Section 86.004–21 includes text that specifies requirements that differ from § 86.094–21. 

Where a paragraph in § 86.094–21 is identical and applicable to § 86.004–21, this may be 

indicated by specifying the corresponding paragraph and the statement “[Reserved]. For 

guidance see § 86.094–21.”

* * * * *
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§ 86.004-25—[Amended]

65. Section 86.004-25 is amended by removing and reserving paragraphs (b)(4)(ii) and 

(b)(4)(iv).

66. Section 86.004-26 is amended as follows:

a. By removing the introductory text.

b. By removing and reserving paragraphs (a) and (b).

c. By revising paragraph (d).

§ 86.004-26 Mileage and service accumulation; emission measurements.

* * * * *

(d)(1) This paragraph (d) applies for heavy-duty engines.

(2)(i) The results of all emission testing shall be supplied to the Administrator. The 

manufacturer shall furnish to the Administrator explanation for voiding any test. The 

Administrator will determine if voiding the test was appropriate based upon the 

explanation given by the manufacturer for the voided test. Tests between test points may

be conducted as required by the Administrator. Data from all tests (including voided 

tests) may be submitted weekly to the Administrator, but shall be delivered to the 

Administrator within 7 days after completion of the test. In addition, all test data shall be 

compiled and provided to the Administrator in accordance with § 86.007–23. Where the 

Administrator conducts a test on a durability data vehicle at a prescribed test point, the 

results of that test will be used in the calculation of the deterioration factor.

(ii) The results of all emission tests shall be recorded and reported to the Administrator. 

These test results shall be rounded as specified in 40 CFR part 1065 to the number of 

decimal places contained in the applicable emission standard expressed to one additional 

significant figure.

(3) Whenever a manufacturer intends to operate and test a vehicle (or engine) that may be 

used for emission data, the manufacturer shall retain in its records all information 

concerning all emission tests and maintenance, including vehicle (or engine) alterations 

to represent other vehicle (or engine) selections. This information shall be submitted, 

including the vehicle (or engine) description and specification information required by 

the Administrator, to the Administrator following the emission test.

(4) Emission testing of any type with respect to any certification vehicle or engine other 

than that specified in this subpart is not allowed except as such testing may be 

specifically authorized by the Administrator.

§ 86.004-28—[Amended]

67. Section 86.004-28 is amended by removing the introductory text and by removing 

and reserving paragraphs (a), (b), (f), and (g).

68. Section 86.004-30 is amended as follows:

a. By revising the introductory text.

b. By removing and reserving paragraphs (a)(4), (a)(5), (a)(10)(i), and (a)(11)(i) and 

(a)(12) through (a)(16).
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c. By removing paragraphs (a)(19) through (a)(21).

d. By removing and reserving paragraphs (b)(1)(i) and (b)(1)(ii).

e. By removing paragraph (b)(1)(ii)(C) and (b)(1)(ii) (D).

f. By removing and reserving paragraph (b)(4).

§ 86.004-30 Certification.

Section 86.004–30 includes text that specifies requirements that differ from § 86.094–30. 

Where a paragraph in § 86.094–30 is identical and applicable to § 86.004–30, this may be 

indicated by specifying the corresponding paragraph and the statement “[Reserved]. For 

guidance see § 86.094–30.”

* * * * *

69. Section 86.004-38 is amended by removing the introductory text, removing and 

reserving paragraph (g), and adding paragraph (i) to read as follows:

§ 86.004-38 Maintenance instructions.

* * * * *

(i) For each new diesel-fueled engine subject to the standards prescribed in § 86.007–11, 

as applicable, the manufacturer shall furnish or cause to be furnished to the ultimate 

purchaser a statement that “This engine must be operated only with ultra low-sulfur 

diesel fuel (meeting EPA specifications for highway diesel fuel, including a 15 ppm 

sulfur cap).”

70. Section 86.005-10 is amended by revising the introductory text and paragraph (c) to 

read as follows:

§ 86.005-10 Emission standards for 2005 and later model year Otto-cycle heavyduty engines and vehicles.

Section 86.005–10 includes text that specifies requirements that differ from § 86.099–10. 

Where a paragraph in § 86.099–10 is identical and applicable to § 86.005–10, this may be 

indicated by specifying the corresponding paragraph and the statement “[Reserved]. For 

guidance see § 86.099–10.”

* * * * *

(c) No crankcase emissions shall be discharged into the ambient atmosphere from any

new 1998 or later model year Otto-cycle heavy-duty engine.

* * * * *

§ 86.005-17 [Removed]

71. Remove § 86.005-17.

[Note to Editor: We are intentionally changing § 86.007-17 from a long section to a 

single sentence that references similar content elsewhere.]

72. Section 86.007-17 is revised to read as follows:

§ 86.007-17 Onboard diagnostics for engines used in applications less than or equal 

to 14,000 pounds GVWR.
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Heavy-duty engines intended to be installed in heavy duty vehicles at or below 14,000 

pounds GVWR that are subject to standards under this subpart must meet onboard 

diagnostic requirements as specified in § 86.1806.

§ 86.007-21—[Amended]

73. Section 86.007-21 is amended as follows:

a. By removing and reserving paragraph (b)(4)(i).

b. By removing paragraphs (b)(9) and (b)(10).

c. By removing and reserving paragraphs (k) and (l).

74. Section 86.007-23 is amended by removing and reserving paragraphs (b)(2), (f), (g), 

and (l) and revising the introductory text and paragraph (c) to read as follows:

§ 86.007-23 Required data.

Section 86.007–23 includes text that specifies requirements that differ from § 86.098–23 

or § 86.001–23. Where a paragraph in § 86.098–23 or § 86.001–23 is identical and 

applicable to § 86.007–23, this may be indicated by specifying the corresponding 

paragraph and the statement “[Reserved]. For guidance see § 86.098–23.” or “[Reserved]. 

For guidance see § 86.001–23.”.

* * * * *

(c) Emission data from certification vehicles and engines. The manufacturer shall submit 

emission data for each applicable emission standard from vehicles and engines tested in 

accordance with applicable test procedures and in such numbers as specified. These data 

shall include zero-mile or zero-hour data, if generated, and emission data generated for 

certification as required under § 86.004-26. However, manufacturers may provide a 

statement in the application for certification that vehicles and engines comply with the 

following standards instead of submitting test data, provided that the statement is 

supported by previous emission tests, development tests, or other appropriate 

information, and good engineering judgment:

(1) Idle CO, smoke, or particulate matter emissions from methanol-fueled or gaseousfueled diesel-cycle certification engines.

(2) Particulate matter emissions from Otto-cycle certification engines or gaseous-fueled 

certification engines.

(3) CO emissions from diesel-cycle certification engines.

(4) Formaldehyde emissions from petroleum-fueled engines. 

(5) Particulate matter and formaldehyde emissions when conducting Selective 

Enforcement Audit testing of Otto-cycle engines.

(6) Smoke from methanol-fueled or petroleum-fueled diesel-cycle certification engines.

(7) Smoke when conducting Selective Enforcement Audit testing of diesel-cycle engines.

(8) Evaporative emissions from vehicles fueled by natural gas, liquefied petroleum gas, 

or hydrogen. 

* * * * *

§ 86.007-30—[Amended]

75. Section 86.007-30 is amended as follows:
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a. By removing and reserving paragraphs (a)(4), (a)(5), (a)(7), (a)(10)(i), (a)(11)(i), and 

(a)(12) through (a)(16).

b. By removing paragraphs (a)(19) through (a)(21).

c. By removing and reserving paragraphs (b)(1)(i), (b)(1)(ii), and (b)(4).

d. By removing paragraph (f).

76. Section 86.007-35 is amended as follows:

a. By revising paragraph (a) introductory text.

b. By removing and reserving paragraphs (a)(1) and (a)(2)

c. By revising paragraph (c).

d. By removing and reserving paragraphs (d), (f), and (i).

§ 86.007-35 Labeling.

* * * * *

(a) The manufacturer of any motor vehicle (or motor vehicle engine) subject to the 

applicable emission standards (and family emission limits, as appropriate) of this subpart, 

shall, at the time of manufacture, affix a permanent legible label, of the type and in the 

manner described below, containing the information hereinafter provided, to all 

production models of such vehicles (or engines) available for sale to the public and 

covered by a Certificate of Conformity under § 86.007–30(a).

* * * * *

(c) Vehicles powered by model year 2007 through 2013 diesel-fueled engines must 

include permanent, readily visible labels on the dashboard (or instrument panel) and near 

all fuel inlets that state “Use Ultra Low Sulfur Diesel Fuel Only”; or “Ultra Low Sulfur 

Diesel Fuel Only”.

* * * * *

§ 86.007-38 [Removed]

77. Remove § 86.007-38.

78. Section 86.008-10 is amended as follows:

a. By removing the introductory text.

b. By revising paragraphs (b) introductory text.

c. By adding paragraph (b)(5).

d. By revising paragraph (e).

§ 86.008-10 Emission standards for 2008 and later model year Otto-cycle heavyduty engines and vehicles.

* * * * *

(b) This paragraph (b) applies as specified in 40 CFR 1037.103. Evaporative emissions 

from heavy-duty vehicles shall not exceed the following standards when measured using 

the test procedures specified in 40 CFR 1037.501. The standards apply equally to 

certification and in-use vehicles. The spitback standard also applies to newly assembled 

vehicles. For certification vehicles only, manufacturers may conduct testing to quantify a 

level of nonfuel background emissions for an individual test vehicle. Such a 

demonstration must include a description of the source(s) of emissions and an estimated 
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decay rate. The demonstrated level of nonfuel background emissions may be subtracted 

from emission test results from certification vehicles if approved in advance by the 

Administrator.

* * * * *

(5) Compressed natural gas vehicles must meet the requirements for fueling connection 

devices as specified in § 86.1813-17(f)(1). Vehicles meeting these requirements are 

deemed to comply with evaporative emission standards.

* * * * *

(e) The standards described in this section do not apply to Otto-cycle medium-duty

passenger vehicles (MDPVs) that are subject to regulation under subpart S of this part, 

except as specified in subpart S of this part. The standards described in this section also 

do not apply to Otto-cycle engines used in such MDPVs, except as specified in subpart S 

of this part. The term “medium-duty passenger vehicle” is defined in § 86.1803.

* * * * *

79. Section 86.010-38 is amended by revising paragraphs (g) and (i) to read as follows:

§ 86.010-38 Maintenance instructions.

* * * * *

(g) Manufacturers are subject to the service-information requirements of § 86.1808-01(f) 

beginning in the 2005 model year for manufacturers of heavy-duty vehicles and heavyduty engines weighing 14,000 pounds gross vehicle weight (GVW) and less that are 

subject to the OBD requirements of this part.

* * * * *

(i) Through model year 2013, the manufacturer shall furnish or cause to be furnished to 

the ultimate purchaser the following statement for each new diesel-fueled engine subject 

to the standards prescribed in § 86.007–11, as applicable: “This engine must be operated 

only with ultra low-sulfur diesel fuel (meeting EPA specifications for highway diesel 

fuel, including a 15 ppm sulfur cap).”

* * * * *

80. Section 86.016-1 is amended by revising paragraphs (a), (b), and (c) and adding 

paragraphs (g) and (h) to read as follows:

§ 86.016-1 General applicability.

(a) Applicability. The provisions of this subpart apply for certain types of new heavyduty engines and vehicles as described in this paragraph (a). Note that this subpart does 

not apply for light-duty vehicles, light-duty trucks, or medium-duty passenger vehicles 

(see subpart S of this part for requirements that apply for those vehicles). In some cases, 

manufacturers of heavy-duty engines and vehicles can choose whether to meet the 

requirements of this subpart or the requirements of subpart S of this part; those provisions 

are therefore considered optional, but only to the extent that manufacturers comply with 

the other set of requirements. In cases where a provision applies only for a certain 

vehicle group based on its model year, vehicle class, motor fuel, engine type, or other 

distinguishing characteristics, the limited applicability is cited in the appropriate section. 
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The provisions of this subpart apply for certain heavy-duty engines and vehicles as 

follows: 

(1) The provisions of this subpart related to exhaust emission standards apply for dieselcycle and Otto-cycle heavy-duty engines installed in vehicles above 14,000 pounds 

GVWR; however, these vehicles may instead be certified under subpart S of this part as 

specified in § 86.1801. 

(2) The provisions of this subpart related to exhaust emission standards apply for engines 

that will be installed in incomplete vehicles at or below 14,000 pounds GVWR; however, 

these vehicles may instead be certified under subpart S of this part as specified in § 

86.1801.

(3) Diesel-cycle and Otto-cycle complete heavy-duty vehicles at or below 14,000 pounds 

GVWR and the corresponding engines are not subject to the provisions of this subpart 

related to exhaust emission standards, except that these provisions are optional for dieselcycle engines installed in such vehicles until those vehicles become subject to the Tier 3 

standards under § 86.1816-18.

(4) The provisions of this subpart related to evaporative emission standards apply for 

diesel-cycle and Otto-cycle heavy-duty vehicles as follows:

(i) These provisions do not apply for vehicles at or below 14,000 pounds GVWR.

(ii) Vehicles above 14,000 pounds GVWR must meet evaporative emission standards as 

specified in 40 CFR 1037.103. This involves meeting the standards specified in §§ 

86.008-10(b) and 86.007-11(b)(3) and (4) until the Tier 3 standards in § 86.1813 start to 

apply.

(iii) Note that diesel-fueled vehicles are not subject to evaporative emissions under this 

part.

(5) The provisions of this subpart related to onboard diagnostics apply for diesel-cycle 

and Otto-cycle heavy-duty engines and vehicles as follows:

(i) Engines installed in vehicles above 14,000 pounds GVWR must meet the onboard 

diagnostic requirements specified in § 86.010-18.

(ii) Engines installed in vehicles at or below 14,000 pounds GVWR must meet the 

onboard diagnostic requirements specified in § 86.1806.

(b) Relationship to subpart S of this part. Unless specified otherwise, if engines are not 

subject to provisions of this subpart or if manufacturers choose not to meet optional 

provisions of this subpart as described in paragraph (a) of this section, those engines must 

be installed in vehicles meeting the corresponding requirements under subpart S of this 

part. If a vehicle and its installed engine comply with a mix of provisions from this 

subpart and from subpart S of this part, the vehicle must be certified under subpart S of 

this part, and the engine does not need to be certified separately.

(c) Greenhouse gas emission standards. See 40 CFR parts 1036 and 1037 for greenhouse 

gas emission standards that apply for heavy-duty engines and vehicles.

* * * * *

(g) Clean alternative fuel conversions. The provisions of this subpart also apply for clean 

alternative fuel conversions as defined in 40 CFR 85.502 of all vehicles described in 

paragraph (a) of this section.
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(h) Turbine engines. Turbine engines are deemed to be compression-ignition engines for 

purposes of this part.

§ 86.079-36 [Removed]

81. Remove § 86.079-36.

82. Section 86.082-2 is amended by adding definitions for “Round” and “United States” 

in alphabetical order to read as follows. 

§ 86.082-2 Definitions.

* * * * *

Round has the meaning given in 40 CFR 1065.1001, unless otherwise specified.

* * * * *

United States has the meaning given in 40 CFR 1068.30. 

* * * * *

§ 86.085-2 [Amended]

83. Section 86.085-2 is amended by removing the definition for “Incomplete gasolinefueled heavy-duty vehicle”. 

* * * * *

84. Section 86.085-20 is revised to read as follows:

§ 86.085-20 Incomplete vehicles, classification.

For purposes of this part:

(a) A heavy-duty gasoline-fueled vehicle is considered to be a complete vehicle if it has 

the primary load carrying device or container attached at the time the vehicle leaves the 

control of the manufacturer of the engine, and is considered to be an incomplete vehicle if 

it does not.

(b) For all other heavy-duty vehicles, a vehicle that has the primary load carrying device 

or container attached at the time the vehicle is introduced into U.S. commerce is 

considered to be a complete vehicle. Vehicles not considered to be complete vehicles are 

incomplete vehicles. For purposes of determining when a vehicle is introduced into U.S. 

commerce, an assembly of motor vehicle parts is deemed to be a vehicle if either of the 

following applies: 

(1) A piece of equipment that is intended for self-propelled use on highways becomes a 

vehicle when it includes at least an engine, a transmission, and a frame. (Note: For 

purposes of this definition, any electrical, mechanical, and/or hydraulic devices attached 

to engines for the purpose of powering wheels are considered to be transmissions.)

(2) A piece of equipment that is intended for self-propelled use on highways becomes a 

vehicle when it includes a passenger compartment attached to a frame with axles.

§ 86.085-37—[Amended]

85. Section 86.085-37 is amended by removing paragraph (b). 

§ 86.087-2 [ Removed]
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86. Remove § 86.087-2.

§ 86.091-29—[Amended]

87. Section 86.091-29 is amended by removing and reserving paragraph (a). 

88. Section 86.094-7 is amended by adding paragraph (h)(6) to read as follows:

§ 86.094-7 Maintenance of records; submittal of information; right of entry.

* * * * *

(h) * * *

(6) EPA may void ab initio a certificate for a vehicle certified to Tier 1 certification 

standards or to the respective evaporative and/or refueling test procedure and 

accompanying evaporative and/or refueling standards as set forth or otherwise referenced 

in § 86.098–10 for which the manufacturer fails to retain the records required in this 

section or to provide such information to the Administrator upon request.

* * * * *

§ 86.094-13 [Removed]

89. Remove § 86.094-13.

§ 86.094-14—[Amended]

90. Section 86.094-14 is amended by removing and reserving paragraphs (c)(5) and 

(c)(7)(i)(A)(1). 

§ 86.094-16 [Removed]

91. Remove § 86.094-16.

§ 86.094-21—[Amended]

92. Section 86.094-21 is amended by removing paragraph (b)(1)(i)(C) and by removing 

and reserving paragraphs (b)(4)(i), (b)(5)(iii)(B), (b)(8), (d), and (g).

§ 86.094-25—[Amended]

93. Section 86.094-25 is amended as follows:

a. By removing and reserving paragraphs (a), (b)(3)(i)(A), and (b)(3)(ii).

b. By removing paragraphs (b)(3)(iii) through (b)(3)(vii).

c. By removing and reserving paragraphs (b)(4) through (b)(6), (d), and (g).

§§ 86.094-26 and 86.094-28 [Removed]

94. Remove §§ 86.094-26 and 86.094-28.

§ 86.094-30—[Amended]

95. Section 86.094-30 is amended as follows:

a. By removing and reserving paragraphs (a)(1)(ii), (a)(4), (a)(5), and (a)(7).

b. By removing paragraphs (a)(9) through (a)(14).

c. By removing and reserving paragraphs (b)(1)(i), (b)(1)(ii), and (b)(4).
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d. By removing and reserving paragraph (d).

§§ 86.095-23, 86.095-26, and 86.095-30 [Removed]

96. Remove §§ 86.095-23, 86.095-26, and 86.095-30.

97. Section 86.095-35 is amended as follows:

a. By removing and reserving paragraphs (a)(1) and (a)(2).

b. By revising paragraph (a)(4) introductory text.

c. By removing and reserving paragraphs (d), (e), and (f).

d. By revising paragraph (g) introductory text.

§ 86.095-35 Labeling.

(a) * * *

(1) – (2) [Reserved]

* * * * *

(4) Heavy-duty vehicles employing a fuel or fuels covered by evaporative emission 

standards. This paragraph (a)(4) applies for vehicles subject to evaporative emission 

standards under this subpart, as described in § 86.016-1(a)(4). See 40 CFR part 1037 for 

provisions that apply in later model years. 

* * * * *

(d) – (f) [Reserved]

(g) Incomplete vehicle fuel tank capacity. This paragraph (g) applies for vehicles subject 

to evaporative emission standards under this subpart, as described in § 86.016-1(a)(4). 

See 40 CFR part 1037 for provisions that apply in later model years. 

* * * * *

§§ 86.096-7, 86.096-8, and 86.096-21 [Removed]

98. Remove §§ 86.096-7, 86.096-8, and 86.096-21.

§ 86.096-24—[Amended]

99. Section 86.096-24 is amended as follows:

a. By removing and reserving paragraphs (a)(8) through (a)(11)

b. By removing and reserving paragraphs (a)(14)(ii), (a)(14)(iii), and (a)(14)(vii).

c. By removing and reserving paragraphs (b)(1), (c)(1), (c)(2), and (d).

d. By removing paragraphs (g) and (h).

§§ 86.096-26, 86.096-30, 86.096-35, 86.096-38, and 86.097-9 [Removed]

100. Remove §§ 86.096-26, 86.096-30, 86.096-35, 86.096-38, and 86.097-9.

§ 86.098-23—[Amended]

101. Section 86.098-23 is amended by removing and reserving paragraphs (b)(1)(i), 

(e)(2), and (e)(3). 

§§ 86.098-24, 86.098-25, 86.098-26, 86.098-28, 86.098-30, 86.098-35, 86.099-8, 86.099-

9, and 86.099-17 [Removed]
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102. Remove §§ 86.098-24, 86.098-25, 86.098-26, 86.098-28, 86.098-30, 86.098-35, 

86.099-8, 86.099-9, and 86.099-17.

Subpart B—[Amended]

103. Section 86.101 is revised to read as follows: 

§ 86.101 General applicability.

(a) General provisions. This subpart describes test procedures for measuring exhaust, 

evaporative, and refueling emissions from motor vehicles subject to emission standards 

under subpart S of this part. This generally includes light-duty vehicles, light-duty 

trucks, and complete heavy-duty vehicles at or below 14,000 pounds GVWR. The 

following provisions apply for all testing under this subpart:

(1) Provisions of this subpart apply to tests performed by both the Administrator and 

manufacturers.

(2) References in this subpart to engine families and emission control systems apply to 

durability groups and test groups as applicable.

(3) Except as noted, heavy-duty vehicles are subject to all the same provisions of this 

subpart that apply to light-duty trucks.

(4) The procedures in this subpart apply for testing vehicles powered by any fuel, except 

as specified in subpart S of this part.

(5) For exhaust emission testing, measure emissions for all pollutants with an applicable 

emission standard. 

(6) All emission control systems designed for production vehicles must be functioning 

during testing. Maintenance to correct component malfunction or failure must be 

authorized in accordance with § 86.1834.

(7) The test sequence for the Federal Test Procedure (FTP) includes steps to precondition 

vehicles for evaporative emission measurements; these steps are required for exhaust 

testing whether or not testing includes evaporative emission measurements.

(8) Evaporative emission measurement procedures of this subpart include specifications 

for testing methanol-fueled vehicles. For vehicles fueled with other oxygenated fuels, 

use good engineering judgment to apply these procedures. For example, if you are 

testing an ethanol-fueled vehicle, perform diagnostics in your evaporative emission 

enclosure with ethanol and propane.

(9) For exhaust emission testing with ethanol-gasoline blends that have less than 25% 

ethanol by volume, if you use NMHC-to-NMOG conversion factors instead of measuring 

oxygenates as described in 40 CFR 1066.635, the testing specifications and diagnostic 

requirements in this part 86 that are specific to ethanol-gasoline blends do not apply. 

(b) Migration to 40 CFR parts 1065 and 1066. This subpart transitions to rely on the test 

procedure specifications in 40 CFR parts 1065 and 1066 as follows:

(1) Through model year 2021, manufacturers may use the test procedures specified in 

paragraph (c) or (d) of this section or, using good engineering judgement, elements of 

both. For any EPA testing before model year 2022, EPA will use the manufacturer's 

selected procedures for determining road load parameters and applying acceptable speedtolerance criteria. For any other parameters, EPA may conduct testing using either of the 
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Page 672 of 1039

specified procedures. As allowed under this part, manufacturers may use carryover data 

from previous model years to demonstrate compliance with emission standards, without 

regard to the provisions of this section.

(2) Manufacturers must use the following procedures before model year 2022:

(i) For vehicles certified to any of the Tier 3 emission standards specified in subpart S of 

this part, determine overall driver accuracy based on driven cycle energy as described in 

40 CFR 1066.425(j).

(ii) Equipment specifications and measurement procedures that are specific to PM 

emissions from 40 CFR part 1066 apply for any vehicles certified to the Tier 3 PM 

emission standards specified in subpart S of this part.

(iii) Use 40 CFR 1066.635 to determine NMOG for any vehicles certified to the Tier 3 

NMOG+NOx emission standards in subpart S of this part.

(3) For model years 2022 and later, manufacturers must use the test procedures specified 

in paragraph (d) of this section.

(c) Interim procedures. Test vehicles as described in this subpart for the appropriate 

model year, through model year 2021, as follows:

(1) Sections 86.106 through 86.115 set forth general testing specifications and equipment 

requirements. Sections 86.116 through 86.126 discuss calibration methods and 

frequency. Sections 86.127 through 86.145 describe procedures for measuring exhaust 

and evaporative emissions. Sections 86.146 through 86.157 lay out refueling test 

procedures. Sections 86.158 through 86.166 cover procedures related to the 

Supplemental Federal Test Procedure and testing related to air conditioning systems. The 

test procedure for measuring fuel system leaks is described in 40 CFR 1066.985.

(2) Alternate equipment, procedures, and calculation methods may be used if shown to 

yield equivalent or superior results, and if approved in advance by the Administrator.

(d) Long-term procedures. Test vehicles as described in 40 CFR parts 1065 and 1066. 

The following requirements from this subpart also apply:

(1) Use fuel for testing and service accumulation as specified in § 86.113.

(2) Perform evaporative emission tests as follows:

(i) Use evaporative testing equipment meeting the specifications in § 86.107. This 

equipment must meet calibration requirements as specified in § 86.117.

(ii) Generate fuel test temperature profiles as described in § 86.129-94(d).

(iii) Follow the general provisions and driving schedules described in 40 CFR part 1066, 

subpart I. Evaporative testing consists of vehicle preconditioning as described in § 

86.132, diurnal measurement as described in § 86.133, running loss testing as described 

in § 86.134, and hot soak testing as described in § 86.138. 

(iv) Calculate emission results as described in § 86.143.

(3) Keep records as described in § 86.142

(4) Perform refueling emission tests, calculate emission results, and keep associated 

records as described in § 86.146 through 86.157.

104. Section 86.102 is revised to read as follows: 

§ 86.102 Definitions.

The definitions in § 86.1803 apply to this subpart.
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§ 86.106-00 [Removed]

105. Section 86.106-00 is removed.

106. Section 86.106-96 is amended by revising paragraph (a)(3) to read as follows: 

§ 86.106-96 Equipment required; overview.

(a) * * *

(3) Fuel, analytical gas, and driving schedule specifications. Fuel specifications for 

exhaust and evaporative emission testing and for mileage accumulation for petroleumfueled and methanol-fueled vehicles are specified in § 86.113. Analytical gases are 

specified in § 86.114. The Urban Dynamometer Driving Schedule (UDDS), US06, and 

SC03 driving schedules, for use in exhaust emission tests, and the New York City Cycle 

(NYCC), for use with the UDDS in running loss tests, are specified in §§ 86.115, 86.130, 

86.159, 86.160, and appendix I to this part.

* * * * *

§ 86.107-96—[Amended]

107. Section 86.107-96 is amended by removing and reserving paragraph (e). 

§§ 86.108-79, 86.110-90 [Removed] 

108. Sections 86.108-79 and 86.110-90 are removed.

109. Section 86.110-94 is amended by revising paragraphs (b)(6)(i) and (d) to read as 

follows:

§ 86.110-94 Exhaust gas sampling system; diesel-cycle vehicles, and Otto-cycle 

vehicles requiring particulate emissions measurements.

* * * * *

(b) * * *

(6) * * *

(i) Sized to permit development of turbulent flow (Reynolds No. >>4000) and complete 

mixing of the exhaust and dilution air between the mixing orifice and each of the two 

sample probes (i.e., the particulate probe and the heated THC sample probe). It is 

recommended that uniform mixing be demonstrated by the user.

* * * * *

(d) Filters, particulate sampling. Use fluorocarbon-coated glass fiber filters or 

fluorocarbon-based (membrane) filters to collect particulate matter, as follows:

(1) Use primary and back-up test filters as follows for particulate measurements:

(i) During each phase of the UDDS, sample dilute exhaust simultaneously with paired 

primary and back-up test filters.

(ii) Position the back-up filter holder 3 to 4 inches downstream of the primary filter 

holder.

(iii) Determine the net weight of particulate material collected on each primary test filter 

and each back-up test filter using the procedure described in § 86.139.

(iv) Determine a ratio of net weights using the following formula:
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(v) If the ratio is greater than 0.95, base the particulate emission calculations on the net 

weight of the primary filter only.

(vi) If the ratio is less than 0.95, base the particulate emission calculations on the 

combined net weights of the back-up test filter and the primary test filter.

(2) The particulate filter must have a 47 mm diameter (37 mm stain area). 

§ 86.111-90 [Removed]

110. Section 86.111-90 is removed.

111. Section 86.111-94 is amended by revising paragraph (b)(3)(vii) to read as follows:

§ 86.111-94 Exhaust gas analytical system.

* * * * *

(b) * * *

(3) * * *

(vii) Using a methane analyzer consisting of a gas chromatograph combined with a FID, 

measure methane according to SAE J1151 (incorporated by reference in § 86.1). 

* * * * *

112. Section 86.113-04 is amended by revising paragraphs (a)(1), (a)(2) and (a)(3)(i) to 

read as follows:

§ 86.113-04 Fuel specifications.

* * * * *

(a) * * *

(1) Gasoline meeting the following specifications, or substantially equivalent 

specifications approved by the Administrator, must be used for exhaust and evaporative 

emission testing: 
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Table 1 of § 86.113-04–Test fuel specifications for gasoline without ethanol

Item Regular Reference 

Procedure1

Research octane, Minimum293 ASTM D2699

Octane sensitivity ASTM D2700 27.5

Distillation Range (°F):

 Evaporated initial boiling point3

 10% evaporated

 50% evaporated

 90% evaporated

 Evaporated final boiling point

75 – 95

120 - 135

200 - 230

300 - 325

415 Maximum

ASTM D86

Hydrocarbon composition (vol %):

 Olefins

 Aromatics

 Saturates

10% Maximum

35% Maximum

Remainder

ASTM D1319

Lead, g/gallon (g/liter), Maximum 0.050

(0.013) ASTM D3237

Phosphorous, g/gallon (g/liter), Maximum 0.005 

(0.0013) ASTM D3231

Total sulfur, wt. %40.0015 – 0.008 ASTM D2622

Dry Vapor Pressure Equivalent (DVPE), 

kPa (psi)5

60.0-63.4 

(8.7-9.2) ASTM D5191

1 ASTM procedures are incorporated by reference in § 86.1.

2 Octane specifications are optional for manufacturer testing. 

3

For testing at altitudes above 1,219 m (4000 feet), the specified range

is 75-105° F.

4

Sulfur concentration will not exceed 0.0045 weight percent for EPA testing.

5

For testing unrelated to evaporative emission control, the specified range is 

54.8-63.7 kPa (8.0-9.2 psi). For testing at altitudes above 1,219 m (4000 feet), 

the specified range is 52.0-55.4 kPa (7.6-8.0 psi). Calculate dry vapor pressure 

equivalent, DVPE, based on the measured total vapor pressure, pT, using the 

following equation: DVPE (kPa) = 0.956∙pT - 2.39 (or DVPE (psi) = 0.956∙pT –

0.347). DVPE is intended to be equivalent to Reid Vapor Pressure using a 

different test method.

(2) Manufacturers may use California test fuels, as follows:

(i) For model year 2014 and earlier vehicles certified for 50-state sale, manufacturers may

perform exhaust emission tests using California Phase 2 gasoline as specified in Chapter 

4 of the California Regulatory Requirements Applicable to the National Low Emission 

Vehicle Program, October 1996 (incorporated by reference in § 86.1). However, the 

Administrator may use or require the use of test fuel meeting the specifications in 

paragraph (a)(1) of this section for confirmatory testing, selective enforcement auditing 

and in-use testing.

(ii) For model year 2015 and later, manufacturers may certify 50-state Tier 2 vehicles 

based on testing used to meet California’s LEV III standards, subject to the following 

provisions:

(A) Manufacturers may perform exhaust and evaporative emission tests using California 

Phase 2 gasoline or California LEV III gasoline. The Administrator may use or require 
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the use of test fuel meeting the specifications in paragraph (a)(1) of this section for 

confirmatory testing, selective enforcement auditing and in-use testing. 

(B) All evaporative testing with California fuel must be conducted with temperatures 

meeting the specifications adopted by the California Air Resources Board.

(C) The vehicles must also meet exhaust and evaporative emission standards at highaltitude conditions as specified in §§ 86.1811-17 and 86.1813-17, except that testing is 

based on the fuel specified in paragraph (a)(1) of this section. 

(D) The vehicle must meet the applicable cold temperature standards using test fuel 

specified for cold temperature testing in § 86.213 .

(3) * * *

(i) Unless otherwise approved by the Administrator, gasoline representative of 

commercial gasoline that will be generally available through retail outlets must be used in 

service accumulation. Unless otherwise approved by the Administrator, where the vehicle 

is to be used for evaporative emission durability demonstration, such fuel must contain 

ethanol as required by § 86.1824–08(f)(1).

* * * * *

§ 86.113-07—[Removed]

113. Remove § 86.113-07.

114. A new § 86.113-15 is added to subpart B to read as follows:

§ 86.113-15 Fuel specifications.

Section 86.113–15 includes text that specifies requirements that differ from § 86.113–94. 

Where a paragraph in § 86.113–94 is identical and applicable to § 86.113–15, this may be 

indicated by specifying the corresponding paragraph and the statement “[Reserved]. For 

guidance see § 86.113–94.”

(a) Gasoline fuel. This paragraph (a) describes how to transition to an ethanol-blend test 

fuel for vehicles certified under subpart S of this part. You may use the test fuels 

specified in § 86.113-04(a) for vehicles that are not yet subject to testing with the new 

fuel. You may use the specified ethanol-blend test fuel anytime earlier than we specify as 

long as you use the corresponding procedures for measuring and calculating emission 

results. See 40 CFR 600.117 for special provisions that apply for emission measurements 

related to fuel economy and greenhouse gases. Manufacturers must certify using E10 test 

fuel as specified in 40 CFR 1065, subpart H, and service accumulation fuel meeting 

applicable specifications as follows::

(1) Except as allowed under paragraph (a)(2) of this section, Use E10 test fuel to 

demonstrate compliance with the Tier 3 exhaust emission standards as specified in § 

86.1811 and 86.1816, and to demonstrate compliance with the Tier 3 evaporative 

emission standards as specified in § 86.1813. 

(2) You may use California test fuels to demonstrate compliance with Tier 3 emission 

standards as follows:

(i) For vehicles certified for 50-state sale, you may instead use California Phase 3 

gasoline (E10) as adopted in California’s LEV III program for exhaust emission testing. 

Through model year 2019, we will also use this E10 fuel for any low-altitude exhaust 
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emission testing with such vehicles. Starting in model year 2020, we may use test fuel 

meeting either California Phase 3 gasoline (E10) or the gasoline (E10) test fuel specified 

in this paragraph (a). For cold temperature testing and for exhaust emission tests at highaltitude conditions, you may certify vehicles through model year 2019 based on testing 

with the gasoline (E0) test fuel specified in § 86.113-04(a); for such vehicles, we may use 

test fuel meeting either the gasoline (E0) test fuel specified in § 86.113-04(a) or the 

gasoline (E10) test fuel specified in this paragraph (a).

(ii) For vehicles that were certified to SULEV exhaust emission standards with a 150,000 

mile useful life under California’s LEV II program and that are eligible to use that 

carryover data for continued certification, you may use that carryover data to demonstrate 

compliance with the exhaust emission standards that apply for Bin 30 vehicles under § 

86.1811-17 for model years 2015 through 2019. The test fuel specifications that applied 

for the original emission measurements under the LEV II program also apply for any

additional exhaust testing under the Tier 3 program, including confirmatory testing, 

selective enforcement auditing, and in-use testing. For vehicles certified under this 

paragraph (a)(2)(ii), use the E10 test fuel specified in 40 CFR 1065.710 for cold 

temperature testing and high-altitude testing.

(iii) For vehicles certified for 50-state sale, you may instead use California test fuel for 

evaporative emission testing as follows:

(A) If you originally certified vehicles in California in model year 2015 or 2016 to PZEV 

standards with California Phase 2 gasoline, you may use that data with carryover vehicles 

to certify to the Tier 3 evaporative emission standards through model year 2019. We will 

use this same fuel to measure diurnal, hot soak, running loss, and SHED rig emissions at 

low-altitude conditions for such vehicles. For refueling, spitback, and high-altitude 

testing, you may use test fuel meeting either the gasoline (E0) test fuel specified in § 

86.113-04(a) or the gasoline (E10) test fuel specified in this paragraph (a); we may use 

either of the specified fuels for our testing. For leak testing, you must use the gasoline 

(E10) test fuel specified in this paragraph (a).

(B) If you certify vehicles to LEV III standards with California Phase 3 gasoline (E10), 

you may use that collection of data to certify to the Tier 3 evaporative emission 

standards. Through model year 2019, we will use this same fuel to measure diurnal, hot 

soak, running loss, SHED rig, and canister bleed emissions (as appropriate) at lowaltitude conditions; starting in model year 2020, we may use either California Phase 3 

gasoline (E10) or the gasoline (E10) test fuel specified in this paragraph (a) for our 

testing with such vehicles. For refueling, spitback, high-altitude, and leak testing, you 

must use the gasoline (E10) test fuel specified in this paragraph (a), except that you may

instead use the gasoline (E0) test fuel specified in § 86.113-04(a) for model year 2015 

and 2016; we will use your selected fuel for our testing. Note that you may no longer 

certify vehicles to the Tier 3 standards based on California’s rig-testing procedures after 

model year 2021, as described in § 86.1813-17(g). 

(C) For evaporative emission testing with California test fuels, perform tests based on the 

test temperatures specified by the California Air Resources Board. 

(3) Except as specified in paragraph (a)(2)(iii) of this section and in this paragraph (a)(3), 

use E10 test fuel to demonstrate compliance with the refueling and spitback emission 
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standards for any vehicles that must be certified to meet the diurnal plus hot soak 

standards with E10 test fuel under paragraphs (a)(1) and (2) of this section. You may

delay using E10 test fuel until model year 2022 for incomplete heavy-duty vehicles not 

certified to refueling emission standards.

(4) If a vehicle uses E10 test fuel for evaporative emission testing and E0 is the 

applicable test fuel for exhaust emission testing, exhaust measurement and reporting 

requirements apply over the course of the evaporative emission test, but the vehicle need 

not meet the exhaust emission standards during the evaporative emission test run. 

(5) For service accumulation, use a commercially available fuel, subject to the additional 

specification in § 86.1824-08(f) for evaporative emissions. 

(b) through (g) [Reserved]. For guidance see § 86.113–94.

115. Section 86.113-94 is amended by removing and reserving paragraphs (a) and (d) 

and revising paragraphs (b)(2), (b)(3), (e), and (f)(3) to read as follows: 

§ 86.113-94— Fuel specifications.

* * * * *

(b) * * *

(2) A diesel fuel designated as “Type 2-D” grade meeting the following specifications, or 

substantially equivalent specifications approved by the Administrator, must be used for 

exhaust emission testing:

Property Unit Type 2-D

Reference 

Procedure1

(i) Cetane Number — 40-50 ASTM D613

(ii) Cetane Index — 40-50 ASTM D976

(iii) Distillation range: 

(A) IBP 

(B) 10 pct. point 

(C) 50 pct. point 

(D) 90 pct. point 

(E) EP 

°F (°C)

340-400 (171.1-204.4)

400-460 (204.4-237.8)

470-540 (243.3-282.2)

560-630 (293.3-332.2)

610-690 (321.1-365.6)

ASTM D86

(iv) Gravity °API 32-37 ASTM D4052

(v) Total sulfur ppm 7-15 ASTM D2622

(vi) Hydrocarbon 

composition: Aromatics, 

minimum (Remainder shall 

be paraffins, naphthenes, and 

olefins)

pct. 27 ASTM D5186

(vii) Flashpoint, min. °F (°C) 130 (54.4) ASTM D93

(viii) Viscosity centistokes 2.0-3.2 ASTM D445

1ASTM procedures are incorporated by reference in § 86.1.

(3) A diesel fuel designated as “Type 2-D” grade meeting the following specifications, or 

substantially equivalent specifications approved by the Administrator, must be used for 

service accumulation: 
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Property Unit Type 2-D

Reference 

Procedure1

(i) Cetane Number — 38-58 ASTM D613

(ii) Cetane Index, minimum — 40 ASTM D976

(iii) 90 percent distillation °F 540-630 ASTM D86

(iv) Gravity °API 30-39 ASTM D4052

(v) Total sulfur Ppm 7-15 ASTM D2622

(vi) Flashpoint, minimum °F (°C) 130 (54.4) ASTM D93

(vii) Viscosity centistokes 1.5-4.5 ASTM D445

1ASTM procedures are incorporated by reference in § 86.1.

* * * * *

(e) Natural gas. (1) A natural gas fuel meeting the following specifications, or 

substantially equivalent specifications approved by the Administrator, must be used for 

exhaust and evaporative emission testing: 

Item Value1

Methane, CH4 Minimum, 89.0 mole percent 

Ethane, C2H6 Maximum, 4.5 mole percent 

C3 and higher Maximum, 2.3 mole percent

C6 and higher Maximum, 0.2 mole percent

Oxygen Maximum, 0.6 mole percent

Inert gases (sum of CO2 and N2) Maximum, 4.0 mole percent

1 All parameters are based on the reference procedures in ASTM D1945 

(incorporated by reference in § 86.1).

(2) The natural gas at ambient conditions must have a distinctive odor potent enough for 

its presence to be detected down to a concentration in air of not over one-fifth of the 

lower limit of flammability.

(3) Natural gas representative of commercially available natural gas fuel generally 

available through retail outlets shall be used in service accumulation for natural gasfueled vehicles.

(4) A natural gas fuel meeting different specifications may be used for testing and service 

accumulation if all the following conditions are met:

(i) The alternate test fuel is commercially available.

(ii) Information acceptable to the Administrator is provided to show that only the 

designated fuel will be used in customer service.

(iii) The Administrator must provide advance written approval for the alternate test fuel.

(f) * * *

(3) The specification range of the fuel to be used under paragraphs (f)(1) and (2) of this 

section shall be measured in accordance with ASTM D2163 (incorporated by reference in 

§ 86.1).

* * * * *

§ 86.115-00 [Removed]
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116. Section 86.115-00 is removed.

117. Section 86.115-78 is amended by revising the section heading and paragraphs (a) 

and (b) introductory text to read as follows:

§ 86.115-78 EPA dynamometer driving schedules.

(a) The driving schedules for the Urban Dynamometer Driving Schedule, US06, SC03, 

and the New York City Cycles are specified in appendix I of this part. The driving 

schedules are defined by a smooth trace drawn through the specified speed vs. time 

relationships. They each consist of a distinct non-repetitive series of idle, acceleration, 

cruise, and deceleration modes of various time sequences and rates.

(b) The driver should attempt to follow the target schedule as closely as possible (refer to 

§ 86.128 for additional cycle driving instructions). The speed tolerance at any given time 

for these schedules, or for a driver's aid chart approved by the Administrator, are as 

follows: 

* * * * *

118. Section 86.117-96 is amended by revising the introductory text and paragraphs (c) 

introductory text, (c)(1)(vii), and (c)(1)(ix) to read as follows:

§ 86.117-96 Evaporative emission enclosure calibrations.

The calibration of evaporative emission enclosures consists of three parts: initial and 

periodic determination of enclosure background emissions (hydrocarbons and methanol); 

initial determination of enclosure internal volume; and periodic hydrocarbon and 

methanol retention check and calibration. Ethanol retention checks may be performed 

instead of methanol retention checks. Alcohol retentions may be omitted if no alcohol -

fueled vehicles will be tested in the evaporative enclosure. For evaporative and refueling 

emission tests with ethanol-gasoline blends that have less than 25% ethanol by volume, if 

you account for ethanol with a mathematical adjustment as described in § 86.1813-

17(a)(1)(iv) instead of measuring ethanol, the testing specifications and diagnostic 

requirements in this part 86 that are specific to ethanol-gasoline blends do not apply. 

Alternate calibration methods may be used if shown to yield equivalent or superior 

results, and if approved in advance by the Administrator; specifically, more extreme 

temperatures may be used for determining calibration without affecting the validity of 

test results.

* * * * *

(c) Hydrocarbon and methanol (organic gas) retention check and calibration. The 

hydrocarbon and methanol (if the enclosure is used for methanol-fueled vehicles) 

retention check provides a check upon the calculated volume and also measures the leak 

rate. The enclosure leak rate shall be determined prior to its introduction into service, 

following any modifications or repairs to the enclosure that may affect the integrity of the 

enclosure, and at least monthly thereafter. The methanol retention check must be 

performed only upon initial installation and after major maintenance, consistent with 

good engineering judgment. If six consecutive monthly retention checks are successfully

completed without corrective action, the enclosure leak rate may be determined quarterly

thereafter as long as no corrective action is required.
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(1) * * *

(vii) Inject into the enclosure 0.5 to 1.0 grams of pure methanol at a recommended 

temperature of at least 150 °F (65 °C) and/or 0.5 to 1.0 grams of pure propane at lab 

ambient temperature. The injected quantity may be measured by volume flow or by mass 

measurement. The method used to measure the quantity of methanol and propane must 

have an accuracy of ±0.5 percent of the measured value (less accurate methods may be 

used with the advance approval of the Administrator).

* * *

(ix) To verify the enclosure calibration, calculate the mass of propane and the mass of 

methanol using the measurements taken in paragraphs (c)(1)(vi) and (viii) of this section. 

See paragraph (d) of this section. This quantity must be within ±2 percent of that 

measured in paragraph (c)(1)(vii) of this section for propane and ±5 percent for methanol. 

Evaluate long-term trends using good engineering judgment to minimize measurement 

bias. Keep records to document such evaluations and make them available to EPA upon 

request.

* * * * *

§§ 86.118-78, 86.127-96, and 86.128-00 [Removed]

119. Sections 86.118-78, 86.127-96, and 86.128-00 are removed.

120. Section 86.128-79 is amended by revising paragraph (d) to read as follows: 

§ 86.128-79 Transmissions.

* * * * *

(d) The vehicle shall be driven with appropriate accelerator pedal movement necessary to 

achieve the speed versus time relationship prescribed by the driving schedule. Both 

smoothing of speed variations and excessive accelerator pedal perturbations are to be 

avoided.

* * * * *

§ 86.129-80—[Amended]

121. Section 86.129-80 is amended by removing and reserving paragraph (a). 

§ 86.130-00 [Removed]

122. Section 86.130-00 is removed.

123. Section 86.130-96 is amended by adding introductory text, revising paragraph (e), 

and adding paragraph (f) to read as follows: 

§ 86.130-96 Test sequence; general requirements.

Paragraphs (a) through (d) of this section are applicable to vehicles tested for the FTP 

test. Paragraph (e) of this section is applicable to vehicles tested for the SFTP 

supplemental tests of air conditioning (SC03) and aggressive driving (US06). Paragraph 

(f) of this section is applicable to all emission testing.

* * * * *
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(e) The supplemental tests for exhaust emissions related to aggressive driving (US06) and 

air conditioning (SC03) use are conducted as stand-alone tests as described in §§ 86.158 

through 86.160. These tests may be performed in any sequence that maintains the 

appropriate preconditioning requirements as specified in § 86.132.

(f) If tests are invalidated after collection of emission data from previous test segments, 

the test may be repeated to collect only those data points needed to complete emission 

measurements. Compliance with emission standards may be determined by combining 

emission measurements from different test runs. If any emission measurements are 

repeated, the new measurements supersede previous values.

§ 86.131-00 [Removed]

124. Section 86.131-00 is removed.

125. Section 86.131-96 is amended by adding paragraphs (f) and (g) to read as follows: 

§ 86.131-96 Vehicle preparation.

* * * * *

(f) For vehicles to be tested for aggressive driving emissions (US06), provide a throttle 

position sensing signal that is compatible with the test dynamometer. This signal provides 

the input information that controls dynamometer dynamic inertia weight adjustments (see 

§§ 86.108-00(b)(2)(ii) and 86.129-00(f)(2)). If a manufacturer chooses not to implement 

dynamic inertia adjustments for a portion or all of their product line, this requirement is 

not applicable.

(g) You may disable any AECDs that have been approved solely for emergency vehicle 

applications under paragraph (4) of the definition of defeat device in § 86.1803. The 

emission standards do not apply when any of these AECDs are active.

§ 86.132-96—[Amended]

126. Section 86.132-96 is amended by removing and reserving paragraph (k). 

127. Section 86.134-96 is amended by revising paragraphs (g)(1)(vi), (g)(1)(xvi), and 

(g)(2)(vi) and adding paragraph (g)(4) to read as follows:

§ 86.134-96 Running loss test.

* * * * *

(g) * * *

(1) * * *

(vi) Set vehicle air conditioning controls as described in 40 CFR 1066.835. 

* * * * *

(xvi) Fuel tank pressure must not exceed 10 inches of water during the running loss test, 

except that temporary exceedances are allowed for vehicles whose tank pressure 

remained below 10 inches of water during the entire outdoor driving period specified in 

§ 86.129. These temporary pressure exceedances may not occur for more than 10 percent 

of the total driving time. 

* * * * *

(2) * * *
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(vi) Set vehicle air conditioning controls as described in 40 CFR 1066.835. 

* * * * *

(4) High-altitude testing. For testing under high-altitude conditions, decrease the target 

ambient and fuel temperatures by 5°F. For example, the fuel temperature profile should 

be adjusted downward based on a nominal starting temperature of 90°F, and the nominal 

temperature in the enclosure should be 90°F.

* * * * *

§ 86.135-00 [Removed]

128. Section 86.135-00 is removed.

129. Section 86.135-90 is amended by revising paragraphs (a) and (d) to read as 

follows: 

§ 86.135-90 Dynamometer procedure.

(a) The dynamometer run consists of two tests— a “cold” start test, after a minimum 12-

hour and a maximum 36-hour soak according to the provisions of §§ 86.132 and 86.133, 

and a “hot” start test following the “cold” start by 10 minutes. Engine startup (with all 

accessories turned off), operation over the UDDS and engine shutdown make a complete 

cold-start test. Engine startup and operation over the first 505 seconds of the driving 

schedule complete the hot start test. The exhaust emissions are diluted with ambient air in 

the dilution tunnel as shown in Figure B94-5 and Figure B94-6. A dilution tunnel is not 

required for testing vehicles waived from the requirement to measure particulate matter. 

Six particulate samples are collected on filters for weighing; the first sample plus backup 

is collected during the first 505 seconds of the cold-start test; the second sample plus 

backup is collected during the remainder of the cold-start test (including shutdown); the 

third sample plus backup is collected during the hot start test. Continuous or batch 

proportional samples of gaseous emissions are collected for analysis during each test 

phase. Use the following measurement procedures for each type of engine:

(1) For gasoline-fueled, natural gas-fueled and liquefied petroleum gas-fueled Otto-cycle 

vehicles, the composite samples collected in bags are analyzed for THC, CO, CO2, CH4, 

and NOx. 

(2) For petroleum-fueled diesel-cycle vehicles (optional for natural gas-fueled, liquefied 

petroleum gas-fueled and methanol-fueled diesel-cycle vehicles), THC is sampled and 

analyzed continuously according to the provisions of § 86.110. Parallel samples of the 

dilution air are similarly analyzed for THC, CO, CO2, CH4, and NOx. 

(3) For natural gas-fueled, liquefied petroleum gas-fueled and methanol-fueled vehicles, 

bag samples are collected and analyzed for THC (if not sampled continuously), CO, CO2, 

CH4, and NOx. 

(4) For methanol-fueled vehicles, methanol and formaldehyde samples are taken for both 

exhaust emissions and dilution air (a single dilution air formaldehyde sample, covering 

the total test period may be collected). Parallel bag samples of dilution air are analyzed 

for THC, CO, CO2, CH4, and NOx. 

* * * * *
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(d) Practice runs over the prescribed driving schedule may be performed at test point, 

provided an emission sample is not taken, for the purpose of finding the appropriate 

throttle action to maintain the proper speed-time relationship, or to permit sampling 

system adjustment. Both smoothing of speed variations and excessive accelerator pedal 

perturbations are to be avoided. When using two-roll dynamometers a truer speed-time 

trace may be obtained by minimizing the rocking of the vehicle in the rolls; the rocking 

of the vehicle changes the tire rolling radius on each roll. This rocking may be minimized 

by restraining the vehicle horizontally (or nearly so) by using a cable and winch.

* * * * *

§ 86.135-94 and 86.137-90 [Removed]

130. Sections 86.135-94 and 86.137-90 are removed.

131. Section 86.137-94 is amended by revising paragraphs (b)(16) through (b)(24) to 

read as follows:

§ 86.137-94 Dynamometer test run, gaseous and particulate emissions.

* * * * *

(b) * * *

(16) Immediately after the end of the sample period, turn off the cooling fan and close the 

engine compartment cover.

(17) Turn off the CVS or disconnect the exhaust tube from the tailpipe(s) of the vehicle.

(18) Repeat the steps in paragraphs (b)(2) through (b)(12) of this section for the hot start 

test, except only two evacuated sample bags, two methanol sample impingers, two 

formaldehyde sample impingers, and one pair of particulate sample filters, as appropriate, 

are required. The step in paragraph (b)(9) of this section shall begin between 9 and 11 

minutes after the end of the sample period for the cold-start test.

(19) At the end of the deceleration scheduled to occur at 505 seconds, simultaneously

turn off gas flow measuring device No. 1 (and the petroleum-fueled diesel hydrocarbon 

integrator No. 1; mark the petroleum-fueled diesel hydrocarbon recorder chart and turn 

off the No. 1 particulate sample pump, if applicable) and position the sample selector 

valve to the “standby” position. (Engine shutdown is not part of the hot start test sample 

period.) Record the measured roll or shaft revolutions (and the No. 1 gas meter reading or 

flow measurement instrument). Carefully remove the third pair of particulate sample 

filters from the holder and place in a clean petri dish and cover, if applicable.

(20) As soon as possible, transfer the hot start “transient” exhaust and dilution air 

samples to the analytical system and process the samples according to § 86.140, 

obtaining a stabilized reading of the exhaust bag sample on all analyzers within 20 

minutes of the end of the sample collection phase of the test. Obtain methanol and 

formaldehyde sample analyses, if applicable, within 24 hours of the end of the sample 

period. If it is not possible to perform analysis on the methanol and formaldehyde 

samples within 24 hours, the samples should be stored in a dark, cold (4-10 °C) 

environment until analysis. Analyze the samples within fourteen days.
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(21) As soon as possible, and in no case longer than one hour after the end of the hot start 

phase of the test, transfer the six particulate filters to the weighing chamber for post-test 

conditioning, if applicable.

(22) Disconnect the exhaust tube from the vehicle tailpipe(s) and drive the vehicle from 

dynamometer.

(23) The CVS or CFV may be turned off, if desired.

(24) Vehicles to be tested for evaporative emissions proceed according to § 86.134; 

vehicles to be tested with the supplemental two-diurnal test sequence for evaporative 

emissions proceed according to § 86.138-96(k). For all others, this completes the test 

sequence.

§ 86.137-96 [Removed]

132. Section 86.137-96 is removed.

133. Section 86.142-90 is amended by revising paragraph (d) to read as follows:

§ 86.142-90 Records required.

* * * * *

(d) Test results. Also include a comparison of drive cycle energy and target cycle energy

relative to both inertia and road load forces as specified in 40 CFR 1066.425 for each 

drive cycle or test phase, as appropriate. 

* * * * *

134. Section 86.143-96 is amended by revising paragraph (c) to read as follows:

§ 86.143-96 Calculations; evaporative emissions.

* * * * *

(c) If the test fuel contains at least 25 % oxygenated compounds by volume, measure the 

concentration of oxygenated compounds directly using a photoacoustic analyzer specified 

in 40 CFR 1065.269 or using impingers as described in 40 CFR 1065.805(f). Calculate 

total hydrocarbon equivalent emissions with the following equation, using density values 

specified in 40 CFR 1066.1005(f):

 

OHCi

THCE THC THC OHCi[THC-FID]

1 OHCi

1

N

i

m

m m  RF

 

     

Where:

mTHCE = the sum of the mass of THCE in the SHED.

mTHC = the mass of THC and all oxygenated hydrocarbons in the SHED, as measured by 

the FID. Calculate THC mass based on ρTHC.

ρTHC = the effective C1-equivalent density of THC as specified in 40 CFR 1066.1005(f).

mOHCi = the mass of oxygenated species i in the SHED.

ρOHCi = the C1-equivalent density of oxygenated species i.

RFOHCi[THC-FID] = the response factor of a THC-FID to oxygenated species i relative to 

propane on a C1-equivalent basis as determined in 40 CFR 1065.845.

* * * * *
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135. Section 86.153-98 is amended by adding paragraph (b)(3) to read as follows:

§ 86.153-98 Vehicle and canister preconditioning; refueling test.

* * * * *

(b) * * *

(3) Manufacturers may use the procedures described in this paragraph (b) to demonstrate 

compliance with the seal test for vehicles with fuel tanks exceeding 35 gallons nominal 

fuel tank capacity, and for any incomplete vehicles.

* * * * *

§§ 86.162-00 and 86.167-17 [Removed]

136. Sections 86.162-00 and 86.167-17 are removed.

137. Subpart C is revised to consist of §§ 86.201 and 86.213 to read as follows:

Subpart C—Emission Regulations for 1994 and Later Model Year Gasoline-Fueled 

New Light-Duty Vehicles, New Light-Duty Trucks and New Medium-Duty 

Passenger Vehicles; Cold Temperature Test Procedures

Sec.

86.201 General applicability.

86.213 Fuel specifications.

Subpart C—Emission Regulations for 1994 and Later Model Year Gasoline-Fueled 

New Light-Duty Vehicles, New Light-Duty Trucks and New Medium-Duty 

Passenger Vehicles; Cold Temperature Test Procedures

§ 86.201 General applicability.

(a) Vehicles are subject to cold temperature testing requirements as described in subpart 

S of this part and 40 CFR part 600. Perform testing to measure CO and NMHC 

emissions and determine fuel economy as described in 40 CFR part 1066; see especially 

40 CFR 1066.710. 

(b) Perform intermediate temperature testing as follows:

(1) For testing during ambient temperatures of less than 50 °F (10 °C), perform testing as 

described in 40 CFR part 1066, subpart H.

(2) For testing at temperatures of 50 °F (10 °C) or higher, perform FTP testing as 

described in 40 CFR part 1066.

(c) Through model year 2021, manufacturers may certify vehicles based on data collected 

according to previously published cold temperature and intermediate temperature testing 

procedures. In addition, we may approve the use of previously published cold 

temperature and intermediate temperature testing procedures for later model years as an 

alternative procedure under 40 CFR 1066.10(c).

(d) Section 86.213 describes special provisions related to test fuel specifications. 

§ 86.213 Fuel specifications.

(a) Gasoline. Use a gasoline test fuel with ethanol (low-level blend only) or without 

ethanol as follows:
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(1) You must certify using service accumulation fuel and E10 test fuel as specified in § 

86.113 for any vehicles required to use a low-level ethanol-gasoline blend test fuel for 

measuring exhaust emissions. You may use this test fuel any time earlier than we 

specify. 

(2) You may use the test fuel specified in this paragraph (a)(2) for vehicles that are not 

yet subject to exhaust testing with an ethanol-blend test fuel under § 86.113. 

Manufacturers may certify based on this fuel using carryover data until testing with the 

ethanol-blend test fuel is required. The following specifications apply for gasoline test 

fuel without ethanol:

Table 1 of § 86.213–Cold temperature test fuel specifications for gasoline without 

ethanol 

Item Regular Premium Reference 

Procedure1

(RON+MON)/2287.8±0.3 92.3±0.5 ASTM D2699

Sensitivity ASTM D2700 37.5 7.5

Distillation Range (°F):

 Evaporated initial boiling point

 10% evaporated

 50% evaporated

 90% evaporated

 Evaporated final boiling point

76 – 96

98 - 118

179 - 214

316 - 346

413 Maximum

76 – 96

105 - 125

195 - 225

316 - 346

413 Maximum

ASTM D86

Hydrocarbon composition (vol %):

 Olefins

 Aromatics

 Saturates

12.5±0.5

26.4±4.0

Remainder

10.5±0.5

32.0±4.0

Remainder

ASTM D1319

Lead, g/gallon 0.01, 

Maximum

0.01, 

Maximum ASTM D3237

Phosphorous, g/gallon 0.005 

Maximum

0.005 

Maximum ASTM D3231

Total sulfur, wt. %30.0015 – 0.008 0.0015 – 0.008 ASTM D2622

RVP, psi 11.5±0.3 11.5±0.3 ASTM D5191

1 ASTM procedures are incorporated by reference in § 86.1.

2 Octane specifications are optional for manufacturer testing. The premium fuel specifications apply for 

vehicles designed to use high-octane premium fuel.

3

Sulfur concentration will not exceed 0.0045 weight percent for EPA testing.

(3) Manufacturers may use the E0 gasoline test fuel specified in § 86.113 for certification 

instead of the fuel specified in paragraph (a)(2) of this section, as long as the change in 

test fuel does not cause cold temperature NMHC, CO, or CO2 emissions to decrease; 

manufacturers must keep records documenting these emission effects and make them 

available to EPA upon request. 

(4) We may approve alternate fuel specifications that are substantially equivalent to those 

in paragraph (a)(2) of this section for a manufacturer’s testing.

(b) Diesel fuel. Diesel fuel for testing under this subpart must meet the specifications for 

low-temperature test fuel in 40 CFR 1065.703. 

Subpart D—[Removed and reserved]
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138. Subpart D, consisting of §§ 86.301-79 through 86.348-79, is removed and 

reserved.

Subpart F—[Amended]

§ 86.505-78 – [Removed]

139. Remove § 86.505-78.

140. Section 86.513-94 is redesignated as § 86.513, and the newly redesignated § 

86.513 is amended by revising paragraphs (a) and (d) to read as follows: 

§ 86.513 Fuel and engine lubricant specifications.

(a) Gasoline. (1) Gasoline meeting the following specifications, or substantially

equivalent specifications approved by the Administrator, must be used for exhaust and 

evaporative emission testing: 
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Table 1 of § 86.513—Gasoline Test Fuel Specifications

Item Value Procedure1

Distillation Range:

1. Initial boiling 

point, °C

2. 10% point, 

°C

3. 50% point, 

°C

4. 90% point, 

°C

5. End point, °C

23.9—35.0 2

48.9—57.2

93.3—110.0

148.9—162.8

212.8 maximum

ASTM D86

Hydrocarbon composition:

1. Olefins, 

volume %

2. Aromatics, 

volume %

3. Saturates

10 maximum

35 maximum

Remainder

ASTM D1319

Lead (organic), g/liter 0.013 maximum ASTM D3237

Phosphorous, g/liter 0.0013 maximum ASTM D3231

Sulfur, weight % 0.008 maximum ASTM D2622

Dry Vapor Pressure 

Equivalent (DVPE), kPa 55.2 to 63.4 3 ASTM D5191

1 ASTM procedures are incorporated by reference in § 86.1.

2

For testing at altitudes above 1,219 m, the specified initial boiling 

point range is (23.9 to 40.6) °C.

3

For testing at altitudes above 1,219 m, the specified volatility range is 

52 to 55 kPa. Calculate dry vapor pressure equivalent, DVPE, based on 

the measured total vapor pressure, pT, using the following equation: 

DVPE (kPa) = 0.956∙pT - 2.39 (or DVPE (psi) = 0.956∙pT – 0.347). DVPE

is intended to be equivalent to Reid Vapor Pressure using a different 

test method.

(2) The following specifications apply for fuels used during service accumulation for 

certification:

(i) Unleaded gasoline and engine lubricants representative of commercial fuels and 

engine lubricants which will be generally available through retail outlets shall be used in 

service accumulation.

(ii) The octane rating of the gasoline used shall be no higher than 4.0 Research octane 

numbers above the minimum recommended by the manufacturer.

(iii) The Reid Vapor Pressure of the gasoline used shall be characteristic of commercial 

gasoline fuel during the season in which the service accumulation takes place.

* * * * *

(d) Natural gas fuel. (1) Natural gas meeting the following specifications, or substantially

equivalent specifications approved by the Administrator, must be used for exhaust and 

evaporative emission testing: 
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Table 2 of § 86.513—Natural Gas Test Fuel Specifications

Item Value1

Methane, CH4 Minimum, 89.0 mole percent 

Ethane, C2H6 Maximum, 4.5 mole percent 

C3 and higher Maximum, 2.3 mole percent

C6 and higher Maximum, 0.2 mole percent

Oxygen Maximum, 0.6 mole percent

Inert gases (sum of CO2 and N2) Maximum, 4.0 mole percent

1 All parameters are based on the reference procedures in ASTM D1945 

(incorporated by reference in § 86.1).

(2) The natural gas at ambient conditions must have a distinctive odor potent enough for 

its presence to be detected down to a concentration in air of not over one-fifth of the 

lower limit of flammability.

(3) Natural gas fuel and engine lubricants representative of commercial fuels and engine 

lubricants generally available through retail outlets shall be used in service accumulation.

(4) A natural gas fuel meeting different specifications may be used for testing and service 

accumulation if all the following conditions are met:

(i) The alternate test fuel is commercially available.

(ii) Information, acceptable to the Administrator, is provided to show that only the 

designated fuel will be used in customer service.

(iii) The Administrator must provide advance written approval for the alternate test fuel.

* * * * *

141. Section 86.515-78 is amended by revising paragraphs (a) and (d) to read as 

follows: 

§ 86.515-78 EPA urban dynamometer driving schedule.

(a) The dynamometer driving schedules are listed in appendix I. The driving schedules 

are defined by a smooth trace drawn through the specified speed vs. time relationships. 

They consist of a nonrepetitive series of idle, acceleration, cruise, and deceleration modes 

of various time sequences and rates. Appropriate driving schedules are as follows:

(1) Class I—Appendix I(b).

(2) Class II—Appendix I(a)(2).

(3) Class III—Appendix I(a)(2).

* * * * *

(d) For motorcycles with an engine displacement less than 50 cc and a top speed less than 

58.7 km/hr (36.5 mph), the speed indicated for each second of operation on the applicable 

Class I driving trace (speed versus time sequence) specified in appendix I(b) shall be 

adjusted downward by the ratio of actual top speed to specified maximum test speed. 

Calculate the ratio with three significant figures by dividing the top speed of the 

motorcycle in km/hr by 58.7. For example, for a motorcycle with a top speed of 48.3 

km/hr (30 mph), the ratio would be 48.3/58.7 = 0.823. The top speed to be used under 

this section shall be indicated in the manufacturer's application for certification, and shall 

be the highest sustainable speed of the motorcycle with an 80 kg rider on a flat paved 

surface. If the motorcycle is equipped with a permanent speed governor that is unlikely to 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 691 of 1039

be removed in actual use, measure the top speed in the governed configuration; otherwise 

measure the top speed in the ungoverned configuration.

Subpart G—[Amended]

142. Section 86.608-98 is amended by revising paragraph (a) to read as follows: 

§ 86.608-98 Test procedures.

(a) The prescribed test procedures are the Federal Test Procedure, as described in subpart 

B of this part, and the cold temperature CO test procedure as described in subpart C of 

this part. For purposes of Selective Enforcement Audit testing, the manufacturer shall 

not be required to perform any of the test procedures in subpart B of this part relating to 

evaporative emission testing, other than refueling emissions testing, except as specified in 

paragraph (a)(2) of this section.

(1) The Administrator may omit any of the testing procedures described in paragraph (a) 

of this section. Further, the Administrator may, on the basis of a written application by a 

manufacturer, approve optional test procedures other than those in subparts B and C of 

this part for any motor vehicle which is not susceptible to satisfactory testing using the 

procedures in subparts B and C of this part.

(2) The following exceptions to the test procedures in subpart B of this part are applicable 

to Selective Enforcement Audit testing:

(i) For mileage accumulation, the manufacturer may use test fuel meeting the 

specifications for mileage and service accumulation fuels of § 86.113. Otherwise, the 

manufacturer may use fuels other than those specified in this section only with the 

advance approval of the Administrator.

(ii) The manufacturer may measure the temperature of the test fuel at other than the 

approximate mid-volume of the fuel tank, as specified in § 86.131–96(a) with only a 

single temperature sensor, and may drain the test fuel from other than the lowest point of 

the tank, as specified in §§ 86.131–96(b) and 86.152–98(a), provided an equivalent 

method is used. Equivalency documentation shall be maintained by the manufacturers 

and shall be made available to the Administrator upon request. Additionally, for any test 

vehicle that has remained under laboratory ambient temperature conditions for at least 6 

hours prior to testing, the vehicle soak described in § 86.132–96(c) may be eliminated 

upon approval of the Administrator. In such cases, the vehicle shall be operated through 

the preconditioning drive described in § 86.132–96(c) immediately following the fuel 

drain and fill procedure described in § 86.132–96(b).

(iii) The manufacturer may perform additional preconditioning on Selective Enforcement 

Audit test vehicles other than the preconditioning specified in § 86.132 only if the 

additional preconditioning was performed on certification test vehicles of the same 

configuration.

(iv) [Reserved] 

(v) The manufacturer may substitute slave tires for the drive wheel tires on the vehicle as 

specified in § 86.135–90(e): Provided, that the slave tires are the same size.

(vi) [Reserved] 

(vii) In performing exhaust sample analysis under § 86.140–94.
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(A) When testing diesel vehicles, or methanol-fueled Otto-cycle vehicles, the 

manufacturer shall allow a minimum of 20 minutes warm-up for the HC analyzer, and for 

diesel vehicles, a minimum of two hours warm-up for the CO, CO2. and NOx analyzers. 

(Power is normally left on infrared and chemiluminescent analyzers. When not in use, the 

chopper motors of the infrared analyzers are turned off and the phototube high voltage 

supply to the chemiluminescent analyzers is placed in the standby position.)

(B) The manufacturer shall exercise care to prevent moisture from condensing in the 

sample collection bags.

(viii) The manufacturer need not comply with § 86.142 or § 86.155, since the records 

required therein are provided under other provisions of this subpart G.

(ix) If a manufacturer elects to perform the background determination procedure 

described in paragraph (a)(2)(xi) of this section in addition to performing the refueling 

emissions test procedure, the elapsed time between the initial and final FID readings shall 

be recorded, rounded to the nearest second rather than minute as described in § 86.154–

98(e)(8). In addition, the vehicle soak described in § 86.153–98(e) shall be conducted 

with the windows and luggage compartment of the vehicle open.

(x) The Administrator may elect to perform a seal test, described in § 86.153–98(b), of 

both integrated and non-integrated systems instead of the full refueling test. When testing 

non-integrated systems, a manufacturer may conduct the canister purge described in § 

86.153–98(b)(1) directly following the preconditioning drive described in § 86.132–96(e) 

or directly following the exhaust emissions test described in § 86.137–96.

(xi) In addition to the refueling test, a manufacturer may elect to perform the following 

background emissions determination immediately prior to the refueling measurement 

procedure described in § 86.154, provided EPA is notified of this decision prior to the 

start of testing in an SEA.

(A) The SHED shall be purged for several minutes immediately prior to the background 

determination. Warning: If at any time the concentration of hydrocarbons, of methanol, 

or of methanol and hydrocarbons exceeds 15,000 ppm C, the enclosure should be 

immediately purged. This concentration provides a 4:1 safety factor against the lean 

flammability limit.

(B) The FID (or HFID) hydrocarbon analyzer shall be zeroed and spanned immediately

prior to the background determination. If not already on, the enclosure mixing fan and the 

spilled fuel mixing blower shall be turned on at this time.

(C) Place the vehicle in the SHED. The ambient temperature level encountered by the test 

vehicle during the entire background emissions determination shall be 80 °F ±3 °F. The 

windows and luggage compartment of the vehicle must be open and the gas cap must be 

secured.

(D) Seal the SHED. Immediately analyze the ambient concentration of hydrocarbons in 

the SHED and record. This is the initial background hydrocarbon concentration.

(E) Soak the vehicle for ten minutes ±1 minute.

(F) The FID (or HFID) hydrocarbon analyzer shall be zeroed and spanned immediately

prior to the end of the background determination.

(G) Analyze the ambient concentration of hydrocarbons in the SHED and record. This is 

the final background hydrocarbon concentration.
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(H) The total hydrocarbon mass emitted during the background determination is 

calculated according to § 86.156. To obtain a per-minute background emission rate, 

divide the total hydrocarbon mass calculated in this paragraph by the duration of the 

soak, rounded to the nearest second, described in paragraph (a)(2)(xi)(G) of this section.

(I) The background emission rate is multiplied by the duration of the refueling 

measurement obtained in paragraph (a)(2)(ix) of this section. This number is then 

subtracted from the total grams of emissions calculated for the refueling test according to 

§ 86.156–98(a) to obtain the adjusted value for total refueling emissions. The final results 

for comparison with the refueling emission standard shall be computed by dividing the 

adjusted value for total refueling mass emissions by the total gallons of fuel dispensed in 

the refueling test as described in § 86.156–98(b).

(xii) In addition to the requirements of subpart B of this part, the manufacturer shall 

prepare gasoline-fueled and methanol-fueled vehicles as follows prior to emission testing:

(A) The manufacturer shall inspect the fuel system to ensure the absence of any leaks of 

liquid or vapor to the atmosphere by applying a pressure of 14.5±0.5 inches of water 

(3.6±0.1 kPa) to the fuel system, allowing the pressure to stabilize, and isolating the fuel 

system from the pressure source. Following isolation of the fuel system, pressure must 

not drop more than 2.0 inches of water (0.5 kPa) in five minutes. If required, the 

manufacturer shall perform corrective action in accordance with paragraph (d) of this 

section and report this action in accordance with § 86.609–98(d).

(B) When performing this pressure check, the manufacturer shall exercise care to neither 

purge nor load the evaporative or refueling emission control systems.

(C) The manufacturer may not modify the test vehicle's evaporative or refueling emission 

control systems by component addition, deletion, or substitution, except to comply with 

paragraph (a)(2)(ii) of this section if approved in advance by the Administrator.

(3) The following exceptions to the test procedures in subpart C of this part are applicable 

to Selective Enforcement Audit testing:

(i) The manufacturer may measure the temperature of the test fuel at other than the 

approximate mid-volume of the fuel tank, as specified in § 86. 107-96(e), and may drain 

the test fuel from other than the lowest point of the fuel tank, provided an equivalent 

method is used. Equivalency documentation shall be maintained by the manufacturer and 

shall be made available to the Administrator upon request.

(ii) In performing exhaust sample analysis under § 86.140, the manufacturer shall 

exercise care to prevent moisture from condensing in the sample collection bags.

(iii) The manufacturer need not comply with § 86.142 since the records required therein 

are provided under other provisions of this subpart G.

(iv) In addition to the requirements of subpart C of this part, the manufacturer shall 

prepare gasoline-fueled vehicles as follows prior to exhaust emission testing:

(A) The manufacturer shall inspect the fuel system to ensure the absence of any leaks of 

liquid or vapor to the atmosphere by applying a pressure of 14.5±0.5 inches of water 

(3.6±0.1 kPa) to the fuel system allowing the pressure to stabilize and isolating the fuel 

system from the pressure source. Following isolation of the fuel system, pressure must 

not drop more than 2.0 inches of water (0.5 kPa) in five minutes. If required, the 
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Page 694 of 1039

manufacturer shall perform corrective action in accordance with paragraph (d) of this 

section and report this action in accordance with § 86.609–98(d).

(B) When performing this pressure check, the manufacturer shall exercise care to neither 

purge nor load the evaporative or refueling emission control system.

(C) The manufacturer shall not modify the test vehicle's evaporative or refueling 

emission control system by component addition, deletion, or substitution, except if 

approved in advance by the Administrator, to comply with paragraph (a)(3)(i) of this 

section. 

* * * * *

143. Section 86.609-98 is amended by revising paragraphs (a), (b), and (c) to read as 

follows: 

§ 86.609-98 Calculation and reporting of test results.

(a) Initial test results are calculated following the test procedures specified in § 86.608–

98(a). Round the initial test results to the number of decimal places contained in the 

applicable emission standard expressed to one additional significant figure. 

(b) Final test results for each test vehicle are calculated by summing the initial test results 

derived in paragraph (a) of this section for each test vehicle, dividing by the number of 

times that specific test has been conducted on the vehicle, and rounding to the same 

number of decimal places contained in the applicable standard expressed to one 

additional significant figure. 

(c) Final deteriorated test results. (1) For each test vehicle. The final deteriorated test 

results for each light-duty vehicle tested for exhaust emissions and/or refueling emissions 

according to subpart B, subpart C, or subpart R of this part are calculated by first 

multiplying or adding, as appropriate, the final test results by or to the appropriate 

deterioration factor derived from the certification process for the engine or 

evaporative/refueling family and model year to which the selected configuration belongs, 

and then by multiplying by the appropriate reactivity adjustment factor, if applicable, and 

rounding to the same number of decimal places contained in the applicable emission 

standard. For the purpose of this paragraph (c), if a multiplicative deterioration factor as 

computed during the certification process is less than one, that deterioration factor is one. 

If an additive deterioration factor as computed during the certification process is less than 

zero, that deterioration factor will be zero.

(2) Exceptions. There are no deterioration factors for light-duty vehicle emissions 

obtained during spitback testing in accordance with § 86.146. Accordingly, for the fuel 

dispensing spitback test, the term “final deteriorated test results” means the final test 

results derived in paragraph (b) of this section for each test vehicle, rounded to the same 

number of decimal places contained in the applicable emission standard. 

* * * * *

§ 86.610-98—[Amended]

144. Section 86.610-98 is amended by removing and reserving paragraph (c)(2).

145. Section 86.612-97 is revised to read as follows: 
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§ 86.612-97 Suspension and revocation of certificates of conformity.

(a) The certificate of conformity is immediately suspended with respect to any vehicle 

failing pursuant to § 86.610-98 (b) effective from the time that testing of that vehicle is 

completed.

(b) The Administrator may suspend the certificate of conformity for a configuration that 

does not pass a selective enforcement audit pursuant to § 86.610–98(c) based on the first 

test, or all tests, conducted on each vehicle. This suspension will not occur before ten 

days after failure to pass the audit.

(c) If the results of vehicle testing pursuant to the requirements of this subpart indicates 

the vehicles of a particular configuration produced at more than one plant do not conform 

to the regulations with respect to which the certificate of conformity was issued, the

Administrator may suspend the certificate of conformity with respect to that 

configuration for vehicles manufactured by the manufacturer in other plants of the 

manufacturer.

(d) The Administrator will notify the manufacturer in writing of any suspension or 

revocation of a certificate of conformity in whole or in part: Except, that the certificate of 

conformity is immediately suspended with respect to any vehicle failing pursuant to § 

86.610-98(b) and as provided for in paragraph (a) of this section.

(e) The Administrator may revoke a certificate of conformity for a configuration when 

the certificate has been suspended pursuant to paragraph (b) or (c) of this section if the 

proposed remedy for the nonconformity, as reported by the manufacturer to the 

Administrator, is one requiring a design change(s) to the engine and/or emission control 

system as described in the Application for Certification of the affected configuration.

(f) Once a certificate has been suspended for a failed vehicle as provided for in paragraph 

(a) of this section, the manufacturer must take the following actions:

(1) Before the certificate is reinstated for that failed vehicle—

(i) Remedy the nonconformity; and

(ii) Demonstrate that the vehicle's final deteriorated test results conform to the applicable 

emission standards or family particulate emission limits, as defined in this part 86 by

retesting the vehicle in accordance with the requirements of this subpart.

(2) Submit a written report to the Administrator within thirty days after successful 

completion of testing on the failed vehicle, which contains a description of the remedy 

and test results for the vehicle in addition to other information that may be required by

this subpart.

(g) Once a certificate has been suspended pursuant to paragraph (b) or (c) of this section, 

the manufacturer must take the following actions before the Administrator will consider 

reinstating such certificate:

(1) Submit a written report to the Administrator which identifies the reason for the 

noncompliance of the vehicles, describes the proposed remedy, including a description of 

any proposed quality control and/or quality assurance measures to be taken by the 

manufacturer to prevent the future occurrence of the problem, and states the date on 

which the remedies will be implemented.

(2) Demonstrate that the engine family or configuration for which the certificate of 

conformity has been suspended does in fact comply with the requirements of this subpart 
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by testing vehicles selected from normal production runs of that engine family or 

configuration at the plant(s) or the facilities specified by the Administrator, in accordance 

with: the conditions specified in the initial test order pursuant to § 86.603 for a 

configuration suspended pursuant to paragraph (b) or (c) of this section. 

(3) If the Administrator has not revoked the certificate pursuant to paragraph (e) of this 

section and if the manufacturer elects to continue testing individual vehicles after 

suspension of a certificate, the certificate is reinstated for any vehicle actually determined 

to have its final deteriorated test results in conformance with the applicable standards 

through testing in accordance with the applicable test procedures.

(h) Once a certificate for a failed engine family or configuration has been revoked under 

paragraph (e) of this section and the manufacturer desires to introduce into commerce a 

modified version of that engine family or configuration, the following actions will be 

taken before the Administrator may issue a certificate for the new engine family or 

configuration:

(1) If the Administrator determines that the proposed change(s) in vehicle design may

have an effect on emission performance deterioration and/or fuel economy, he/she shall 

notify the manufacturer within five working days after receipt of the report in paragraph 

(g)(1) of this section whether subsequent testing under this subpart will be sufficient to 

evaluate the proposed change(s) or whether additional testing will be required.

(2) After implementing the change(s) intended to remedy the nonconformity, the 

manufacturer shall demonstrate, if the certificate was revoked pursuant to paragraph (e) 

of this section, that the modified vehicle configuration does in fact conform with the 

requirements of this subpart by testing vehicles selected from normal production runs of 

that modified vehicle configuration in accordance with the conditions specified in the 

initial test order pursuant to § 86.603. The Administrator shall consider this testing to 

satisfy the testing requirements of § 86.079–32 or § 86.079–33 if the Administrator had 

so notified the manufacturer. If the subsequent testing results in a pass decision pursuant 

to the criteria in § 86.610–98(c), the Administrator shall reissue or amend the certificate, 

if necessary, to include that configuration: Provided, that the manufacturer has satisfied 

the testing requirements specified in paragraph (h)(1) of this section. If the subsequent 

audit results in a fail decision pursuant to the criteria in § 86.610-98(c), the revocation 

remains in effect. Any design change approvals under this subpart are limited to the 

modification of the configuration specified by the test order.

(i) A manufacturer may at any time subsequent to an initial suspension of a certificate of 

conformity with respect to a test vehicle pursuant to paragraph (a) of this section, but not 

later than fifteen (15) days or such other period as may be allowed by the Administrator 

after notification of the Administrator's decision to suspend or revoke a certificate of 

conformity in whole or in part pursuant to paragraph (b), (c) or (e) of this section, request 

that the Administrator grant such manufacturer a hearing as to whether the tests have 

been properly conducted or any sampling methods have been properly applied.

(j) After the Administrator suspends or revokes a certificate of conformity pursuant to 

this section or notifies a manufacturer of his intent to suspend, revoke or void a certificate 

of conformity under § 86.007-30(e) or § 86.1850, and prior to the commencement of a 

hearing under § 86.614, if the manufacturer demonstrates to the Administrator's 
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Page 697 of 1039

satisfaction that the decision to suspend, revoke or void the certificate was based on 

erroneous information, the Administrator shall reinstate the certificate.

(k) To permit a manufacturer to avoid storing non-test vehicles when conducting testing 

of an engine family or configuration subsequent to suspension or revocation of the 

certificate of conformity for that engine family or configuration pursuant to paragraph 

(b), (c), or (e) of this section, the manufacturer may request that the Administrator 

conditionally reinstate the certificate for that engine family or configuration. The 

Administrator may reinstate the certificate subject to the condition that the manufacturer 

consents to recall all vehicles of that engine family or configuration produced from the 

time the certificate is conditionally reinstated if the engine family or configuration fails 

the subsequent testing and to remedy any nonconformity at no expense to the owner.

Subpart H—[Removed and reserved]

146. Subpart H, consisting of §§ 86.701-94 through 86.709-99, is removed and 

reserved.

Subpart L—[Amended]

147. Section 86.1102-87 is amended by adding a definition of “Round” to paragraph 

(b) in alphabetical order to read as follows:

§ 86.1102-87 Definitions.

* * * * *

Round has the meaning given in 40 CFR 1065.1001.

* * * * *

148. Section 86.1105-87 is amended by revising paragraph (e) to read as follows:

§ 86.1105-87 Emission standards for which nonconformance penalties are 

available.

* * * * *

(e) The values of COC50 , COC90 , and MC50 in paragraphs (a) and (b) of this section are 

expressed in December 1984 dollars. The values of COC50 , COC90 , and MC50 in 

paragraphs (c) and (d) of this section are expressed in December 1989 dollars. The values 

of COC50 , COC90 , and MC50 in paragraph (f) of this section are expressed in December 

1991 dollars. The values of COC50 , COC90 , and MC50 in paragraphs (g) and (h) of this 

section are expressed in December 1994 dollars. The values of COC50 , COC90 , and 

MC50 in paragraph (i) of this section are expressed in December 2001 dollars. The values 

of COC50 , COC90 , and MC50 in paragraph (j) of this section are expressed in December 

2011 dollars. These values shall be adjusted for inflation to dollars as of January of the 

calendar year preceding the model year in which the NCP is first available by using the 

change in the overall Consumer Price Index, and rounded to the nearest whole dollar.

* * * * *

Subpart M—[Removed and reserved]
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149. Subpart M, consisting of §§ 86.1201-90 through 86.1246-96, is removed and 

reserved.

Subpart N--Exhaust Test Procedures for Heavy-duty Engines

150. The heading of subpart N is revised to read as set forth above. 

151. Section 86.1305-2010 is redesignated as § 86.1305, and newly redesignated § 

86.1305 is revised to read as follows:

§ 86.1305 Introduction; structure of subpart.

(a) This subpart specifies the equipment and procedures for performing exhaust-emission 

tests on Otto-cycle and diesel-cycle heavy-duty engines. Subpart A of this part sets forth 

the emission standards and general testing requirements to comply with EPA certification 

procedures.

(b) Use the applicable equipment and procedures for spark-ignition or compressionignition engines in 40 CFR part 1065 to determine whether engines meet the duty-cycle 

emission standards in subpart A of this part. Measure the emissions of all regulated 

pollutants as specified in 40 CFR part 1065. Use the duty cycles and procedures specified 

in §§ 86.1333, 86.1360, and 86.1362. Adjust emission results from engines using 

aftertreatment technology with infrequent regeneration events as described in § 86.004–

28.

(c) The provisions in §§ 86.1370 and 86.1372 apply for determining whether an engine 

meets the applicable not-to-exceed emission standards.

(d) Measure smoke using the procedures in subpart I of this part for evaluating whether 

engines meet the smoke standards in subpart A of this part.

(e) Use the fuels specified in 40 CFR part 1065 to perform valid tests, as follows:

(1) For service accumulation, use the test fuel or any commercially available fuel that is 

representative of the fuel that in-use engines will use.

(2) For diesel-fueled engines, use the ultra low-sulfur diesel fuel specified in 40 CFR part 

1065 for emission testing.

(3) For gasoline-fueled engines, use the appropriate E10 fuel specified in 40 CFR part 

1065; however, through model year 2021 you may instead use the appropriate E0 fuel 

specified in 40 CFR part 1065, with the exception that the E0 fuel must have sulfur 

concentration between 0.0015 and 0.008 weight percent and research octane of at least 

93. Starting in model year 2022, you may certify up to 5 percent of your nationwide sales 

volume of engines certified under subpart A of this part in a given model year based on 

this E0 test fuel if those engines are certified with carryover data.

(f) You may use special or alternate procedures to the extent we allow them under 40 

CFR 1065.10. In addition, for 2010 and earlier model year engines, you may use 

modified test procedures as needed to conform to the procedures that were specified at 

the time of emission testing for the model year in question.

(g) This subpart applies to you as a manufacturer, and to anyone who does testing for 

you.
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(h) For testing conducted with engines installed in vehicles, including field testing 

conducted to measure emissions under Not-To-Exceed test procedures, use the test 

procedures and equipment specified in 40 CFR part 1065, subpart J.

§§ 86.1305-90, 86.1305-2004, 86.1306-07, 86.1306-96, 86.1308-84, 86.1309-90, 

86.1310-90, 86.1310-2007, 86.1311-94, 86.1312-88, 86.1312-2007, 86.1313-94, 

86.1313-98, 86.1313-2004, 86.1313-2007, 86.1314-94, 86.1316-94, 86.1318-84, 

86.1319-90, 86.1320-90, 86.1321-94, 86.1322-84, 86.1323-84, 86.1323-2007, 86.1324-

84, 86.1325-94, 86.1326-90, 86.1327-96, 86.1327-98, 86.1330-90, and 86.1332-90 

[Removed]

152. Remove §§ 86.1305-90, 86.1305-2004, 86.1306-07, 86.1306-96, 86.1308-84, 

86.1309-90, 86.1310-90, 86.1310-2007, 86.1311-94, 86.1312-88, 86.1312-2007, 

86.1313-94, 86.1313-98, 86.1313-2004, 86.1313-2007, 86.1314-94, 86.1316-94, 

86.1318-84, 86.1319-90, 86.1320-90, 86.1321-94, 86.1322-84, 86.1323-84, 86.1323-

2007, 86.1324-84, 86.1325-94, 86.1326-90, 86.1327-96, 86.1327-98, 86.1330-90, and 

86.1332-90.

153. Section 86.1333-2010 is redesignated as § 86.1333, and newly redesignated § 

86.1333 is amended by revising paragraphs (a)(1), (c), and (d) to read as follows:

§ 86.1333 Transient test cycle generation.

(a) * * *

(1) To unnormalize rpm, use the following equations:

(i) For diesel engines:

%  

112

rpm MaxTest Speed Curb Idle Speed

Actualrpm Curb Idle Speed

 

 

Where:

Max Test Speed = the maximum test speed as calculated in 40 CFR part 1065.

(ii) For Otto-cycle engines:

%  

100

rpm MaxTest Speed Curb Idle Speed

Actualrpm Curb Idle Speed

 

 

Where:

Max Test Speed = the maximum test speed as calculated in 40 CFR part 1065.

* * * * *

(c) Clutch operation. Manual transmission engines may be tested with a clutch. If used, 

the clutch shall be disengaged at all zero percent speeds, zero percent torque points, but 

may be engaged up to two points preceding a non-zero point, and may be engaged for 

time segments with zero percent speed and torque points of durations less than four 

seconds. 

(d) Determine idle speeds as specified in 40 CFR 1065.510.
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§§ 86.1333-90, 86.1334-84, 86.1335-90, 86.1336-84, 86.1337-96, 86.1337-2007, 

86.1338-84, 86.1338-2007, 86.1339-90, 86.1340-90, 86.1340-94, 86.1341-90, 86.1341-

98, 86.1342-90, 86.1342-94, 86.1343-88, and 86.1344-94 [Removed]

154. Remove §§ 86.1333-90, 86.1334-84, 86.1335-90, 86.1336-84, 86.1337-96, 

86.1337-2007, 86.1338-84, 86.1338-2007, 86.1339-90, 86.1340-90, 86.1340-94, 

86.1341-90, 86.1341-98, 86.1342-90, 86.1342-94, 86.1343-88, and 86.1344-94.

155. Section 86.1360-2007 is redesignated as § 86.1360, and newly redesignated § 

86.1360 is amended by revising paragraphs (b)(1), (c), and (f)(3) to read as follows:

§ 86.1360 Supplemental emission test; test cycle and procedures.

* * * * *

(b) * * *

(1) Perform testing as described in § 86.1362 for determining whether an engine meets 

the applicable standards when measured over the supplemental emission test.

* * * * *

(c) The engine speeds A, B and C, referenced in the table in paragraph (b)(1) of this 

section, must be determined as follows:

Speed A = nlo+ 0.25 × (nhi−nlo)

Speed B = nlo+ 0.50 × (nhi−nlo)

Speed C = nlo+ 0.75 × (nhi−nlo)

Where: nhi= High speed as determined by calculating 70% of the maximum power. The 

highest engine speed where this power value occurs on the power curve is defined as nhi.

nlo= Low speed as determined by calculating 50% of the maximum power. The lowest 

engine speed where this power value occurs on the power curve is defined as nlo.

Maximum power = the maximum observed power calculated according to the engine 

mapping procedures defined in 40 CFR 1065.510.

* * * * *

(f) * * *

(3) If the Maximum Allowable Emission Limit for any point, as calculated under 

paragraphs (f)(1) and (2) of this section, is greater than the applicable Not-to-Exceed 

limit (if within the Not-to-Exceed control area defined in § 86.1370(b)), then the 

Maximum Allowable Emission Limit for that point shall be defined as the applicable 

Not-to-Exceed limit.

* * * * *

156. Section 86.1362-2010 is redesignated as § 86.1362, and newly redesignated § 

86.1362 is revised to read as follows:

§ 86.1362 Steady-state testing with a ramped-modal cycle.

This section describes how to test engines under steady-state conditions. 

(a) Measure emissions by testing the engine on a dynamometer with the following 

ramped-modal duty cycle to determine whether it meets the applicable steady-state 

emission standards:
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RMC

mode

Time in mode

(seconds)

Engine

speed 1,2

Torque

(percent) 2,3

1a Steady-state 170 Warm Idle 0

1b Transition 20 Linear Transition Linear Transition.

2a Steady-state 173 A 100

2b Transition 20 Linear Transition Linear Transition.

3a Steady-state 219 B 50

3b Transition 20 B Linear Transition.

4a Steady-state 217 B 75

4b Transition 20 Linear Transition Linear Transition.

5a Steady-state 103 A 50

5b Transition 20 A Linear Transition.

6a Steady-state 100 A 75

6b Transition 20 A Linear Transition.

7a Steady-state 103 A 25

7b Transition 20 Linear Transition Linear Transition.

8a Steady-state 194 B 100

8b Transition 20 B Linear Transition.

9a Steady-state 218 B 25

9b Transition 20 Linear Transition Linear Transition.

10a Steady-state 171 C 100

10b Transition 20 C Linear Transition.

11a Steady-state 102 C 25

11b Transition 20 C Linear Transition.

12a Steady-state 100 C 75

12b Transition 20 C Linear Transition.

13a Steady-state 102 C 50

13b Transition 20 Linear Transition Linear Transition.

14 Steady-state 168 Warm Idle 0

1

Speed terms are defined in 40 CFR part 1065.

2Advance from one mode to the next within a 20-second transition phase. During the transition phase, 

command a linear progression from the speed or torque setting of the current mode to the speed or torque 

setting of the next mode.

3The percent torque is relative to maximum torque at the commanded engine speed.

(b) Perform the ramped-modal test as described in 40 CFR part 1065.

(c) For 2007 through 2010 model years, manufacturers may follow the mode order 

described in this paragraph (c) instead of the mode order specified in paragraph (a) of this 

section. Any EPA testing with these engines will rely on the same procedure used by the 

manufacturer for certification.
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RMC

mode

Time in mode

(seconds)

Engine

speed1,2

Torque

(percent) 2,3

1a Steady-state 170 Warm Idle 0

1b Transition 20 Linear Transition Linear Transition

2a Steady-state 170 A 100

2b Transition 20 A Linear Transition

3a Steady-state 102 A 25

3b Transition 20 A Linear Transition

4a Steady-state 100 A 75

4b Transition 20 A Linear Transition

5a Steady-state 103 A 50

5b Transition 20 Linear Transition Linear Transition

6a Steady-state 194 B 100

6b Transition 20 B Linear Transition

7a Steady-state 219 B 25

7b Transition 20 B Linear Transition

8a Steady-state 220 B 75

8b Transition 20 B Linear Transition

9a Steady-state 219 B 50

9b Transition 20 Linear Transition Linear Transition

10a Steady-state 171 C 100

10b Transition 20 C Linear Transition

11a Steady-state 102 C 25

11b Transition 20 C Linear Transition

12a Steady-state 100 C 75

12b Transition 20 C Linear Transition

13a Steady-state 102 C 50

13b Transition 20 Linear Transition Linear Transition

14 Steady-state 168 Warm Idle 0

1

Speed terms are defined in 40 CFR part 1065.

2 Advance from one mode to the next within a 20-second transition phase. During the transition phase, 

command a linear progression from the speed or torque setting of the current mode to the speed or torque 

setting of the next mode.

3 The percent torque is relative to maximum torque at the commanded engine speed.

§§ 86.1362-2007 and 86.1363-2007 [Removed]

157. Remove §§ 86.1362-2007 and 86.1363-2007.

158. Section 86.1370-2007 is redesignated as § 86.1370, and newly redesignated § 

86.1370 is amended by revising paragraphs (a), (b)(3), (b)(6), and (f) introductory text to 

read as follows:

§ 86.1370 Not-To-Exceed test procedures. 

(a) General. The purpose of this test procedure is to measure in-use emissions of heavyduty diesel engines while operating within a broad range of speed and load points (the 

Not-To-Exceed Control Area) and under conditions which can reasonably be expected to 

be encountered in normal vehicle operation and use. Emission results from this test 

procedure are to be compared to the Not-To-Exceed Limits specified in § 86.007–

11(a)(4), or to later Not-To-Exceed Limits. The Not-To-Exceed Limits do not apply for 

engine-starting conditions. Tests conducted using the procedures specified in this subpart 
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Page 703 of 1039

are considered valid Not-To-Exceed tests (Note: duty cycles and limits on ambient 

conditions do not apply for Not-To-Exceed tests).

(b) * * *

(3) Notwithstanding the provisions of paragraphs (b)(1) and (2) of this section, all 

operating speed and load points with brake specific fuel consumption (BSFC) values 

within 5% of the minimum BSFC value of the engine. For the purposes of this 

requirement, BFSC must be calculated under the general test cell conditions specified in 

40 CFR part 1065. The manufacturer may petition the Administrator at certification to 

exclude such points if the manufacturer can demonstrate that the engine is not expected to 

operate at such points in normal vehicle operation and use. Engines equipped with 

drivelines with multi-speed manual transmissions or automatic transmissions with a finite 

number of gears are not subject to the requirements of this paragraph (b)(3).

* * * * *

(6)(i) For petroleum-fueled diesel cycle engines, the manufacturer may identify particular 

engine-vehicle combinations and may petition the Administrator at certification to 

exclude operating points from the Not-to-Exceed Control Area defined in paragraphs 

(b)(1) through (5) of this section if the manufacturer can demonstrate that the engine is 

not capable of operating at such points when used in the specified engine-vehicle 

combination(s).

(ii) For diesel cycle engines that are not petroleum-fueled, the manufacturer may petition 

the Administrator at certification to exclude operating points from the Not-to-Exceed 

Control Area defined in paragraphs (b)(1) through (5) of this section if the manufacturer 

can demonstrate that the engine is not expected to operate at such points in normal 

vehicle operation and use.

* * * * *

(f) NTE cold temperature operating exclusion. Engines equipped with exhaust gas 

recirculation (EGR) whose operation within the NTE control area specified in paragraph 

(b) of this section when operating during cold temperature conditions as specified in

paragraph (f)(1) of this section are not subject to the NTE emission limits during the 

specified cold temperature conditions.

* * * * *

§ 86.1372-2007 ]Redesignated as § 86.1372]

159. Section 86.1372-2007 is redesignated as § 86.1372.

§§ 86.1375-2007 and 86.1380-2004 [Removed]

160. Remove §§ 86.1375-2007 and 86.1380-2004.

Subpart O—[Removed and reserved]

161. Subpart O, consisting of §§ 86.1401 through 86.1442, is removed and reserved.

Subpart R—[Removed and reserved]

162. Subpart R, consisting of §§ 86.1701-99 through 86.1780-99, is removed and 

reserved.
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Subpart S – [Amended]

163. Section 86.1801-12 is amended by revising paragraphs (a) through (d) and adding 

paragraphs (e), (f), and (g) to read as follows:

§ 86.1801-12 Applicability.

(a) Applicability. The provisions of this subpart apply to certain types of new vehicles as 

described in this paragraph (a). Where the provisions apply for a type of vehicle, they 

apply for vehicles powered by any fuel, unless otherwise specified. In some cases, 

manufacturers of heavy-duty engines and vehicles can choose whether to meet the 

requirements of this subpart or the requirements of subpart A of this part; those 

provisions are therefore considered optional, but only to the extent that manufacturers 

comply with the other set of requirements. In cases where a provision applies only to a 

certain vehicle group based on its model year, vehicle class, motor fuel, engine type, or 

other distinguishing characteristics, the limited applicability is cited in the appropriate 

section. References in this subpart to 40 CFR part 86 generally apply to Tier 2 and older 

vehicles, while references to 40 CFR part 1066 generally apply to Tier 3 and newer 

vehicles; see 40 CFR 86.101 for detailed provisions related to this transition. The 

provisions of this subpart apply to certain vehicles as follows:

(1) The provisions of this subpart apply for light-duty vehicles and light-duty trucks. 

(2) The provisions of this subpart apply for medium-duty passenger vehicles. The 

provisions of this subpart also apply for other complete heavy-duty vehicles at or below 

14,000 pounds GVWR, except as follows:

(i) The provisions of this subpart are optional for diesel-cycle vehicles through model 

year 2017; however, if you are using the provisions of § 86.1811-17(b)(9) or § 86.1816-

18(b)(8) to transition to the Tier 3 exhaust emission standards, the provisions of this 

subpart are optional for those diesel-cycle vehicles until the start of the Tier 3 phase-in 

for those vehicles.

(ii) Greenhouse gas emission standards apply as specified in 40 CFR parts 1036 and 1037 

instead of the standards specified in this subpart.

(3) The provisions of this subpart generally do not apply to incomplete heavy-duty 

vehicles or to complete vehicles above 14,000 pounds GVWR (see subpart A of this part 

and 40 CFR part 1037). However, this subpart applies to such vehicles in the following 

cases: 

(i) Heavy duty vehicles above 14,000 pounds GVWR and all sizes of incomplete heavyduty vehicles may be optionally certified to the exhaust emission standards in this subpart 

that apply for heavy-duty vehicles.

(ii) The evaporative emission standards apply for incomplete heavy-duty vehicles at or 

below 14,000 pounds GVWR. Evaporative emission standards also apply for complete 

and incomplete heavy-duty vehicles above 14,000 pounds GVWR as specified in 40 CFR 

1037.103.

(iii) Refueling emission standards apply for complete heavy-duty vehicles above 14,000 

pounds GVWR as specified in 40 CFR 1037.103. All sizes of incomplete heavy-duty 

vehicles may be optionally certified to the refueling emission standards in this subpart.
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(iv) The onboard diagnostic requirements in this subpart apply for incomplete vehicles at 

or below 14,000 pounds GVWR, but not for any vehicles above 14,000 pounds GVWR.

(4) The provisions of this subpart are optional for diesel-fueled Class 3 heavy-duty 

vehicles in a given model year if those vehicles are equipped with engines certified to the 

appropriate standards in § 86.007-11 for which less than half of the engine family’s sales 

for the model year in the United States are for complete Class 3 heavy-duty vehicles. 

This includes engines sold to all vehicle manufacturers. If you are the original 

manufacturer of the engine and the vehicle, base this showing on your sales information. 

If you manufacture the vehicle but are not the original manufacturer of the engine, you 

must use your best estimate of the original manufacturer's sales information.

(5) If you optionally certify vehicles to standards under this subpart, those vehicles are 

subject to all the regulatory requirements as if the standards were mandatory.

(b) Relationship to subpart A of this part. Unless specified otherwise, if heavy-duty

vehicles are not subject to provisions of this subpart or if manufacturers choose not to 

meet optional provisions of this subpart as described in paragraph (a) of this section, the 

engines installed in those vehicles must meet the corresponding requirements under 

subpart A of this part. If a vehicle and its installed engine comply with a mix of 

provisions from this subpart and from subpart A of this part, the vehicle must be certified 

under this subpart, and the engine does not need to be certified separately.

(c) Clean alternative fuel conversions. The provisions of this subpart also apply to clean 

alternative fuel conversions as defined in 40 CFR 85.502 of all vehicles described in 

paragraph (a) of this section.

(d) Small-volume manufacturers. Special certification procedures are available for smallvolume manufacturers as described in § 86.1838.

(e) You. The term “you” in this subpart refers to manufacturers subject to the emission 

standards and other requirements of this subpart.

(f) Vehicle. The term “vehicle”, when used generically, does not exclude any type of 

vehicle for which the regulations apply (such as light-duty trucks). 

(g) Complete and incomplete vehicles. Several provisions in this subpart, including the 

applicability provisions described in this section, are different for complete and 

incomplete vehicles. We differentiate these vehicle types as described in § 86.085-20.

* * * * *

164. Section 86.1803-01 is amended as follows:

a. By removing the definition for “Certification Short Test (CST)”.

b. By adding definitions for “Class 2b” and “Class 3” in alphabetical order.

c. By removing the definition for “Complete heavy-duty vehicle”.

d. By revising the definitions for “Family emission limit (FEL)”, “Heavy-duty vehicle”, 

and “Hybrid electric vehicle (HEV)”.

e. By removing the definitions for “Incomplete heavy-duty vehicle” and “Incomplete

truck”.

f. By adding definitions for “LEV III” and “Low-altitude conditions” in alphabetical 

order.

g. By removing the definition for “Low altitude conditions”.
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h. By revising the definition for “Non-methane organic gases (NMOG)”.

i. By adding a definition for “Rated power” in alphabetical order.

j. By removing the definition for “Round, rounded or rounding”.

k. By adding definitions for “Round (rounded, rounding)”, “Section 177 states”, “Tier 3”, 

and “United States” in alphabetical order.

l. By revising the definition for “U.S. sales”.

m. By adding definitions for “Volatile liquid fuel” and “We (us, our)” in alphabetical 

order.

§ 86.1803-01 Definitions. 

* * * * *

Class 2b means relating to heavy-duty vehicles at or below 10,000 pounds GVWR.

Class 3 means relating to heavy-duty vehicles above 10,000 pounds GVWR and at or 

below 14,000 pounds GVWR.

* * * * *

Emergency vehicle means one of the following:

(1) For the greenhouse gas emission standards in § 86.1818, emergency vehicle means a 

motor vehicle manufactured primarily for use as an ambulance or combination 

ambulance-hearse or for use by the U.S. Government or a State or local government for 

law enforcement.

(2) For the OBD requirements in § 86.1806, emergency vehicle means a motor vehicle 

manufactured primarily for use in medical response or for use by the U.S. Government or 

a State or local government for law enforcement or fire protection.

* * * * *

Family emission limit (FEL) means a bin standard or emission level selected by the 

manufacturer that serves as the applicable emission standard for the vehicles in the family

or test group in the context of fleet-average standards or emission credits. 

* * * * *

Heavy-duty vehicle means any motor vehicle rated at more than 8,500 pounds GVWR 

or that has a vehicle curb weight of more than 6,000 pounds or that has a basic vehicle 

frontal area in excess of 45 square feet. Note that MDPVs are heavy-duty vehicles that 

are in many cases subject to requirements that apply for light-duty trucks.

* * * * *

Hybrid electric vehicle (HEV) means a motor vehicle which draws propulsion energy

from onboard sources of stored energy that are both an internal combustion engine or 

heat engine using consumable fuel, and a rechargeable energy storage system such as a 

battery, capacitor, hydraulic accumulator, or flywheel. This includes plug-in hybrid 

electric vehicles.

* * * * *

LEV III means relating to the LEV III emission standards in Title 13, §§1961.2 and 

1976 of the California Code of Regulations, as adopted by the California Air Resources 

Board (incorporated by reference in § 86.1). 

* * * * *

Low-altitude conditions means a test altitude less than 549 meters (1,800 feet).

* * * * *
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Non-methane organic gases (NMOG) means the sum of oxygenated and nonoxygenated hydrocarbons contained in a gas sample as measured using the procedures 

described in 40 CFR 1066.635.

* * * * *

Rated power means an engine’s maximum power output in an installed configuration, 

as determined by using SAE J1349 (incorporated by reference in § 86.1).

* * * * *

Round (rounded or rounding) has the meaning given in 40 CFR 1065.1001, unless 

otherwise specified.

* * * * *

Section 177 states means the states that have adopted California’s motor vehicle 

standards for a particular model year under section 177 of the Clean Air Act (42 U.S.C. 

7507).

* * * * *

Tier 3 means relating to the Tier 3 emission standards described in §§ 86.1811-17, 

86.1813-17, and 86.1816-18. 

* * * * *

United States has the meaning given in 40 CFR 1068.30. 

* * * * *

U.S. sales means, unless otherwise specified, sales in any state or territory of the 

United States except for California or the section 177 states. Sale location is based on the 

point of first sale to a dealer, distributor, fleet operator, broker, or other entity. 

* * * * *

Volatile liquid fuel means any fuel other than diesel or biodiesel that is a liquid at 

atmospheric pressure and has a Reid Vapor Pressure higher than 2.0 pounds per square 

inch.

* * * * *

We (us, our) means the Administrator of the Environmental Protection Agency and 

any authorized representatives.

* * * * *

§ 86.1805-01 [Removed]

165. Remove § 86.1805-01.

166. A new § 86.1805-17 is added to subpart S to read as follows:

§ 86.1805-17 Useful life.

(a) General provisions. The useful life values specified in this section apply for all 

exhaust, evaporative, refueling, and OBD emission requirements described in this 

subpart, except for standards that are specified to apply only at certification. These useful 

life requirements also apply to all air conditioning leakage credits, air conditioning 

efficiency credits, and other credit programs used by the manufacturer to comply with the 

fleet-average CO2 emission standards in § 86.1818. Useful life values are specified as a 

given number of calendar years and miles of driving, whichever comes first.
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(b) Greenhouse gas pollutants. The emission standards in § 86.1818 apply for a useful 

life of 10 years or 120,000 miles for LDV and LLDT and 11 years or 120,000 miles for 

HLDT and HDV. Manufacturers may alternatively certify based on a longer useful life 

as specified in paragraph (d) of this section.

(c) Cold temperature emission standards. The cold temperature NMHC emission 

standards in § 86.1811 apply for a useful life of 10 years or 120,000 miles for vehicles at 

or below 6,000 pounds GVWR, and 11 years or 120,000 miles for vehicles above 6,000 

pounds GVWR. The cold temperature CO emission standards in § 86.1811 apply for a 

useful life of 5 years or 50,000 miles.

(d) Criteria pollutants. The useful life provisions of this paragraph (d) apply for all 

emission standards not covered by paragraph (b) or (c) of this section. Except as 

specified in paragraph (f) of this section and in §§ 86.1811, 86.1813, and 86.1816, the 

useful life for LDT2, HLDT, MDPV, and HDV is 15 years or 150,000 miles. The useful 

life for LDV and LDT1 is 10 years or 120,000 miles. Manufacturers may optionally

certify LDV and LDT1 to a useful life of 15 years or 150,000 miles, in which case the 

longer useful life would apply for all the standards and requirements covered by this 

paragraph (d). 

(e) Intermediate useful life. Where exhaust emission standards are specified for an 

intermediate useful life, these standards apply for five years or 50,000 miles.

(f) Interim provisions. The useful life provisions of § 86.1805-12 apply for vehicles not 

yet subject to Tier 3 requirements. For example, vehicles above 6,000 pounds GVWR 

are not subject to the useful life provisions in this section until model year 2019 unless 

manufacturers voluntarily certify to the Tier 3 requirements earlier than the regulations 

require. Also, where the transition to Tier 3 standards involves a phase-in percentage for 

a given standard, vehicles not included as part of the phase-in portion of the fleet 

continue to be subject to the useful life provisions of § 86.1805-12 with respect to that 

standard. The useful life values for a set of vehicles may be different for exhaust and 

evaporative emission standards in 2021 and earlier model years; if vehicles have different 

useful life values for evaporative and exhaust emission standards, the evaporative useful 

life applies for the OBD requirements related to the leak standard and the exhaust useful 

life applies for all other OBD requirements.

§§ 86.1806-01 and 86.1806-04 [Removed]

167. Remove §§ 86.1806-01 and 86.1806-04.

168. Section 86.1806-05 is amended by revising the section heading and paragraphs 

(b) introductory text, (h), and (j) and adding paragraph (k)(7) to read as follows:

§ 86.1806-05 Onboard diagnostics.

* * * * *

(b) Malfunction descriptions. The OBD system must detect and identify malfunctions in 

all monitored emission-related powertrain systems or components according to the 

following malfunction definitions as measured and calculated in accordance with test 

procedures set forth in subpart B of this part (chassis-based test procedures), excluding 

those test procedures defined as “Supplemental” test procedures in § 86.004–2 and 
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codified in §§ 86.158, 86.159, and 86.160. For clean alternative fuel conversion 

manufacturers, your OBD system is expected to detect and identify malfunctions in all 

monitored emission-related powertrain systems or components according to the 

malfunction definitions described in this paragraph (b) as measured and calculated in 

accordance with the chassis-based test procedures set forth in subpart B of this part to the 

extent feasible, excluding the elements of the Supplemental FTP (see § 86.1803). 

However, at a minimum, systems must detect and identify malfunctions as described in 

paragraph (k)(7) of this section.

* * * * *

(h) Incorporation by reference. The following additional requirements apply based on 

industry standard specifications, which are incorporated by reference in § 86.1:

(1) The following requirements apply for standardized on-board to off-board 

communications:

(i) Starting in model year 2008, light-duty vehicles and light-duty trucks must comply

with ISO 15765-4:2005(E), “Road Vehicles-Diagnostics on Controller Area Network 

(CAN)—Part 4: Requirements for emission-related systems”, January 15, 2005. 

(ii) Starting in model year 2008, heavy-duty vehicles must comply with the protocol 

described in paragraph (h)(1)(i) of this section, or the following set of SAE standards: 

SAE J1939-11, Revised October 1999; SAE J1939-13, July 1999; SAE J1939-21, 

Revised April 2001; SAE J1939-31, Revised December 1997; SAE J1939-71, Revised 

January 2008; SAE J1939-73, Revised September 2006; SAE J1939-81, May 2003.

(iii) Note that for model years 1996 through 2007 manufacturers could instead comply 

with the protocols specified in SAE J1850, ISO 9141-2, or ISO 14230-4.

(2) Light-duty vehicles and light-duty trucks must meet the following additional 

specifications:

(i) Basic diagnostic data (as specified in §§ 86.094-17(e) and (f)) shall be provided in the 

format and units in SAE J1979 “E/E Diagnostic Test Modes—Equivalent to ISO/DIS 

15031-5: Revised, May 2007.

(ii) Diagnostic trouble codes shall be consistent with SAE J2012 “Diagnostic Trouble 

Code Definitions—Equivalent to ISO/DIS 15031-6: April 30, 2002”, (Revised, April 

2002).

(iii) The connection interface between the OBD system and test equipment and diagnostic 

tools shall meet the functional requirements of SAE J1962 “Diagnostic Connector—

Equivalent to ISO/DIS 15031-3: December 14, 2001” (Revised, April 2002).

(iv) SAE J1930, Revised April 2002. All acronyms, definitions and abbreviations shall be 

formatted according to this industry standard. Alternatively, manufacturers may use SAE 

J2403, Revised August 2007.

(v) All equipment used to interface, extract, and display OBD-related information shall 

meet SAE J1978 “OBD II Scan Tool” Equivalent to ISO 15031-4: December 14, 2001”, 

(Revised, April 2002).

* * * * *

(j) California OBDII compliance option. Manufacturers may comply with California’s 

OBD requirements instead of meeting the requirements of this section as follows:
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(1) Through the 2006 model year, demonstration of compliance with California OBDII 

requirements (Title 13 California Code of Regulations § 1968.2 (13 CCR 1968.2)), as 

modified, approved and filed on April 21, 2003 (incorporated by reference, see § 86.1), 

shall satisfy the requirements of this section, except that compliance with 13 CCR 

1968.2(e)(4.2.2)(C), pertaining to 0.02 inch evaporative leak detection, and 13 CCR 

1968.2(d)(1.4), pertaining to tampering protection, are not required to satisfy the 

requirements of this section. Also, the deficiency provisions of 13 CCR 1968.2(i) do not 

apply. In addition, demonstration of compliance with 13 CCR 1968.2(e)(16.2.1)(C), to 

the extent it applies to the verification of proper alignment between the camshaft and 

crankshaft, applies only to vehicles equipped with variable valve timing. 

(2) For 2007 through 2012 model year vehicles, demonstration of compliance with 

California OBD II requirements (Title 13 California Code of Regulations § 1968.2 (13 

CCR 1968.2)), approved on November 9, 2007 (incorporated by reference, see § 86.1), 

shall satisfy the requirements of this section, except that compliance with 13 CCR 

1968.2(e)(4.2.2)(C), pertaining to 0.02 inch evaporative leak detection, and 13 CCR 

1968.2(d)(1.4), pertaining to tampering protection, are not required to satisfy the 

requirements of this section. Also, the deficiency provisions of 13 CCR 1968.2(k) do not 

apply. In addition, demonstration of compliance with 13 CCR 1968.2(e)(15.2.1)(C), to 

the extent it applies to the verification of proper alignment between the camshaft and 

crankshaft, applies only to vehicles equipped with variable valve timing. 

(3) Beginning with the 2013 model year, manufacturers may demonstrate compliance 

with California’s 2013 OBD requirements as described in § 86.1806-17(a). 

(4) For all model years, the deficiency provisions of paragraph (i) of this section and the 

evaporative leak detection requirement of paragraph (b)(4) of this section, if applicable, 

apply to manufacturers selecting this paragraph for demonstrating compliance.

(k) * * *

(7) For clean alternative fuel conversion manufacturers (e.g., natural gas, liquefied 

petroleum gas, methanol, ethanol), in lieu of the requirements specified for other 

manufacturers in this paragraph (k), you may demonstrate that the malfunction indicator 

light will illuminate, at a minimum, under any of the following circumstances when the 

vehicle is operated on the applicable alternative fuel:

(i) Otto-cycle. A catalyst is replaced with a defective catalyst system where the catalyst 

brick for the monitored volume has been removed (i.e., empty catalyst system) resulting 

in an increase of 1.5 times the NMOG (or NMOG+NOx) standard or FEL above the 

NMOG (or NMOG+NOx) emission level measured using a representative 4000 mile 

catalyst system. 

(ii) Diesel. (A) If monitored for emissions performance—a catalyst is replaced with a 

defective catalyst system where the catalyst brick for the monitored volume has been 

removed (i.e., empty catalyst can) resulting in exhaust emissions exceeding 1.5 times the 

applicable standard or FEL for NOX (or NMOG+NOx) or PM.

(B) If monitored for performance—a particulate trap is replaced with a trap that has 

catastrophically failed.

(iii) Misfire. (A) Otto-cycle. An engine misfire condition is induced that completely

disables one or more cylinders, either through mechanical or electrical means, resulting in 
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exhaust emissions exceeding 1.5 times the applicable standards or FEL for CO, NMOG, 

or NOX (or NMOG+NOx).

(B) Diesel. An engine misfire condition resulting in complete lack of cylinder firing is 

induced and is not detected.

(iv) If so equipped, any oxygen sensor is replaced with a completely defective oxygen 

sensor, or an electronic simulation of such, resulting in exhaust emissions exceeding 1.5 

times the applicable standard or FEL for CO, NMOG, or NOX (or NMOG+NOx).

(v) If so equipped and applicable, a vapor leak is introduced in the evaporative and/or 

refueling system (excluding the tubing and connections between the purge valve and the 

intake manifold) greater than or equal in magnitude to a leak caused by a 0.040 inch 

diameter orifice, or the evaporative purge air flow is blocked or otherwise eliminated 

from the complete evaporative emission control system. At a minimum, gas cap removal 

or complete venting of the evaporative and/or refueling system may be introduced 

resulting in a gross leak of the complete evaporative emission control system.

(vi) A malfunction condition is induced resulting in complete disablement in any

emission-related powertrain system or component, including but not necessarily limited 

to, the exhaust gas recirculation (EGR) system, if equipped, the secondary air system, if 

equipped, and the fuel control system, singularly resulting in exhaust emissions 

exceeding 1.5 times the applicable emission standard or FEL for PM, CO, NMOG, or 

NOX (or NMOG+NOx).

(vii) A malfunction condition is induced that completely disables an electronic emissionrelated powertrain system or component not otherwise described in this paragraph (k) that 

either provides input to or receives commands from the onboard computer resulting in a 

measurable impact on emissions. At a minimum, manufacturers may be required to

perform this disablement on critical inputs and outputs where lack of the input and output 

disables an entire monitor as described in this paragraph (k)(7)(vii), disables multiple 

monitors (e.g., two or more) used by the onboard computer, or renders the entire onboard 

computer and its functions inoperative.

(viii) Clean alternative fuel conversion manufacturers must use good engineering 

judgment to induce malfunctions and may perform more stringent malfunction 

demonstrations than described in this paragraph (k)(7). In addition, the Administrator 

reserves the right to request a clean alternative fuel conversion manufacturer to perform 

stricter demonstration requirements, to the extent feasible, on clean alternative fuel 

conversions.

* * * * *

169. A new § 86.1806-17 is added to subpart S to read as follows:

§ 86.1806-17 Onboard diagnostics.

Model year 2017 and later vehicles must have onboard diagnostic (OBD) systems as 

described in this section. OBD systems must generally detect malfunctions in the 

emission control system, store trouble codes corresponding to detected malfunctions, and 

alert operators appropriately.

(a) Vehicles must comply with the 2013 OBD requirements adopted for California as 

described in this paragraph (a). California’s 2013 OBD-II requirements are part of Title 
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13, §1968.2 of the California Code of Regulations, approved on July 31, 2013 

(incorporated by reference in § 86.1). The following clarifications and exceptions apply 

for vehicles certified under this subpart:

(1) For vehicles not certified in California, references to vehicles meeting certain 

California Air Resources Board emission standards are understood to refer to the 

corresponding EPA emission standards for a given family, where applicable. Use good 

engineering judgment to correlate the specified standards with the bin standards that 

apply under this subpart. 

(2) Vehicles must comply with OBD requirements throughout the useful life as specified 

in § 86.1805. If the specified useful life is different for evaporative and exhaust 

emissions, the useful life specified for evaporative emissions applies for monitoring 

related to fuel-system leaks and the useful life specified for exhaust emissions applies for 

all other parameters.

(3) The purpose and applicability statements in 13 CCR 1968.2(a) and (b) do not apply.

(4) The anti-tampering provisions in 13 CCR 1968.2(d)(1.4) do not apply.

(5) The requirement to verify proper alignment between the camshaft and crankshaft 

described in 13 CCR 1968.2(e)(15.2.1)(C) applies only for vehicles equipped with 

variable valve timing.

(6) The deficiency provisions described in paragraph (c) of this section apply instead of 

13 CCR 1968.2(k).

(7) For emergency vehicles only, the provisions of 13 CCR 1968.2(e)(6.2.1) related to 

monitoring and identification of air-fuel ratio cylinder imbalance, as part of the fuel 

system monitoring, do not apply until model year 2020, unless the vehicle met the 

requirements in 2016 or earlier model years. 

(8) Apply thresholds for exhaust emission malfunctions from Tier 3 vehicles based on the 

thresholds calculated for the corresponding bin standards in the California LEV II 

program as prescribed for the latest model year in CCR 1968.2(e)(1) through (3). For 

example, for Tier 3 Bin 160 standards, apply the threshold that applies for the LEV 

standards. For cases involving Tier 3 standards that have no corresponding bin standards 

from the California LEV II program, use the next highest LEV II bin. For example, for 

Tier 3 Bin 50 standards, apply the threshold that applies for the ULEV standards. You 

may apply thresholds that are more stringent than we require under this paragraph (a)(8).

(b) The following additional provisions apply:

(1) Model year 2017 and later vehicles must meet the OBD system requirements 

described in this paragraph (b)(1). When monitoring conditions are satisfied, test 

vehicles must detect the presence of a leak with an effective leak diameter at or above 

0.020 inches, illuminate the MIL, and store the appropriate confirmed diagnostic trouble

codes (DTCs) (13 CCR1968.2 refers to these as fault codes). For a 0.020 inch leak, the 

DTC(s) shall be a generic SAE J2012 DTC that is specific to an EVAP system very small 

leak (e.g., P0456, P04EE, or P04EF) or an equivalent manufacturer-specific DTC that we 

approve. Conduct testing using an O’Keefe Controls Co. metal “Type B” orifice with a 

diameter of 0.020 inches or an alternate orifice diameter approved under 13 CCR 

1968.2(e)(4.2.3) or (e)(4.2.4).
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(i) Use the methodology specified in 13 CCR 1968.2(h)(2.2) to select test vehicles to 

demonstrate that the OBD system is capable of detecting a 0.020 inch leak installed in the 

evaporative system, except that the manufacturer may use production-representative 

vehicles instead of the vehicle options specified in 13 CCR 1968.2(h)(2.3). 

(ii) Perform tests in the laboratory, with or without a dynamometer, or on an outdoor road 

surface, as necessary to exercise the vehicle’s ability to detect leaks in the evaporative 

system.

(iii) Perform at least two tests to evaluate the OBD system for leaks that are installed near 

the fuel fill pipe and near the canister. The implanted leak near the fuel fill pipe must be 

at the fuel cap or between the fuel cap and the fuel tank. The implanted leak near the 

canister must be in the vapor line between the canister and the fuel tank, or between the 

canister and the purge valve). If a vehicle has multiple canisters or fuel fill pipes, repeat 

the testing to evaluate the system for implanted leaks corresponding to each canister and 

fuel fill pipe. You may propose to implant leaks in different locations (e.g., near the 

purge valve); we will approve your alternate leak location if it more effectively 

demonstrates leak detection for your particular fuel system design. 

(iv) If vehicle operation is needed to fulfill preconditioning (i.e., when engine-off tests 

require driving before vehicle shutdown to enable the engine-off monitor) or monitoring 

conditions for leak detection under this paragraph (b)(1) utilize an FTP cycle, Unified 

cycle, or some other specified operating cycle that will satisfy the approved monitoring or 

preconditioning conditions without the interference of approved deficiencies. Continue 

vehicle operation as needed to illuminate the MIL and store the appropriate DTCs.

(v) Emission measurements are not required during this OBD evaporative system leak 

monitoring demonstration testing.

(vi) For test groups not selected for testing in a given model year, you may instead 

provide a statement in the application for certification, consistent with good engineering 

judgment, that vehicles meet leak-detection requirements based on previous OBD tests, 

development tests, or other appropriate information. For any untested test groups, the 

statement specified in § 86.1844-01(d)(8) applies with regard to the leak monitoring 

requirement. We may ask you to provide the data and other information that formed the 

basis for your statement. Select test groups in later model years such that testing will 

rotate to cover your whole product line over time.

(vii) Submit the following information in the application for certification:

(A) Describe the test sequence.

(B) Identify the driving cycle used and the time expired and distance driven before the 

MIL illuminated.

(C) Identify the ranges of in-use environmental and vehicle operating conditions for 

which the vehicle will not meet the leak-detection specifications described in this 

paragraph (b)(1). To meet this requirement, you may give us the same information you 

gave the California Air Resources Board regarding enable conditions for the evaporative 

system leak monitor. 

(D) Identify the confirmed and permanent DTCs set by the OBD system during testing.

(E) Include the freeze frame information stored at the point the fault is detected.
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(F) Include the SAE J1979 test results (e.g., Mode/Service $06) corresponding to the 

DTCs that were stored during the test.

(viii) If you have one or more vehicle models in model year 2016 that do not comply with 

the leak requirements in 13 CCR 1968.2(e)(4), you may comply with the requirements of 

this paragraph (b)(1) in model year 2017 by substituting model year 2016 vehicles on an 

equal-percentage basis. Demonstrate this by calculating the percentage of vehicles 

subject to OBD requirements under this subpart that meet the requirements of this 

paragraph (b)(1) in model years 2016 and 2017; the sum of these two percentage values 

must be at or above 100 percent. Any model year 2017 vehicles not meeting the 

requirements of this paragraph (b)(1), as allowed by this paragraph (b)(1)(viii), may not 

be counted as compliant Tier 3 vehicles under the alternative phase-in specified in § 

86.1813-17(g)(2)(ii).

(2) For vehicles subject to the leak standard in § 86.1813, OBD systems must record in 

computer memory the result of the most recent successfully completed diagnostic check 

for a 0.020 inch leak. Someone must be able to use the data to determine the miles driven 

since the last check occurred, the pass/fail result, and whether there has been a check 

since the computer memory was last cleared (e.g., from a scan tool command or battery

disconnect). The system may be designed to keep data only from the previous 750 miles 

of driving. (Note: This 750 mile requirement is related to the use of the OBD evaporative 

leak monitor in the leak test and should not be confused with either the minimum or 

maximum distance values specified in Table G-19 of SAE J1979.) The data must be 

reported in a standardized format consistent with other data required for the OBD system. 

The results must be scan-readable.

(3) For vehicles with fuel tanks exceeding 25 gallons nominal fuel tank capacity, you 

may request our approval for a leak threshold greater than 0.020 inches, up to a 

maximum value of 0.040 inches. We will generally approve a leak threshold equal to the 

standard that applies under § 86.1813.

(c) You may ask us to accept as compliant a vehicle that does not fully meet specific 

requirements under this section. Such deficiencies are intended to allow for minor 

deviations from OBD standards under limited conditions. We expect vehicles to have 

functioning OBD systems that meet the objectives stated in this section. The following 

provisions apply regarding OBD system deficiencies:

(1) Except as specified in paragraph (d) of this section, we will not approve a deficiency

that involves the complete lack of a major diagnostic monitor, such as monitors related to 

exhaust aftertreatment devices, oxygen sensors, air-fuel ratio sensors, NOx sensors, 

engine misfire, evaporative leaks, and diesel EGR (if applicable). 

(2) We will approve a deficiency only if you show us that full compliance is infeasible or 

unreasonable considering any relevant factors, such as the technical feasibility of a given 

monitor, or the lead time and production cycles of vehicle designs and programmed 

computing upgrades. 

(3) Our approval for a given deficiency applies only for a single model year, though you 

may continue to ask us to extend a deficiency approval in renewable one-year increments. 

We may approve an extension if you demonstrate an acceptable level of effort toward 
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Page 715 of 1039

compliance and show that the necessary hardware or software modifications would pose 

an unreasonable burden. 

(d) For alternative-fuel vehicles, manufacturers may request a waiver from specific 

requirements for which monitoring may not be reliable for operation with the alternative 

fuel. However, we will not waive requirements that we judge to be feasible for a 

particular manufacturer or vehicle model.

(e) For alternative-fuel conversions, manufacturers may meet the requirements of § 

86.1806-05 instead of the requirements of this section. 

(f) You may ask us to waive certain requirements in this section for emergency vehicles. 

We will approve your request for an appropriate duration if we determine that the OBD 

requirement in question could harm system performance in a way that would impair a 

vehicle’s ability to perform its emergency functions.

(g) The following interim provisions describe an alternate implementation schedule for 

the requirements of this section in certain circumstances:

(1) Manufacturers may delay complying with all the requirements of this section, and 

instead meet all the requirements that apply under § 86.1806-05, for any heavy-duty

vehicles that are not yet subject to the Tier 3 standards in § 86.1816.

(2) Except as specified in this paragraph (g)(2), small-volume manufacturers may delay

complying with all the requirements of this section until model year 2022, and instead 

meet all the requirements that apply under § 86.1806-05 during those years. This 

provision does not apply for a vehicle model if it is identical to a 2016 vehicle model that 

was certified to meet California’s OBD requirements under § 86.1806-05(j)(3). A 

vehicle model is considered identical to one from model year 2016 if it is certified in the 

current year based on the same test data for exhaust or evaporative emissions under the 

carryover data provisions of this subpart. 

(3) Manufacturers may disregard the requirements of this section that apply above 8,500 

pounds GVWR before model year 2019 and instead meet all the requirements that apply

under § 86.1806-05. This also applies for model year 2019 vehicles from a test group 

with vehicles that have a Job 1 date on or before [INSERT DATE FOUR YEARS 

AFTER FRM SIGNATURE] (see 40 CFR 85.2304).

§ 86.1807-01—[Amended]

170. Section 86.1807-01 is amended by removing and reserving paragraph (a)(3)(ix).

171. Section 86.1808-01 is amended as follows:

a. By revising paragraphs (f)(1), (f)(3) introductory text, (f)(6)(ii)(D), (f)(7)(i) 

introductory text, (f)(7)(ii)(B), (f)(10)(ii), (f)(13) introductory text, (f)(13)(iv), and 

(f)(16)(i). 

b. By adding paragraph (g).

§ 86.1808-01 Maintenance instructions.

* * * * *

(f) * * *

(1) Applicability. Manufacturers are subject to the provisions of this paragraph (f) for 

1996 model year for and later light-duty vehicles and light-duty trucks. Manufacturers 
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Page 716 of 1039

are subject to the provisions of this paragraph (f) for 2005 model year and later heavyduty vehicles at or below 14,000 pounds GVWR and the corresponding engines that are 

subject to the OBD requirements of this part.

* * * * *

(3) Information dissemination. Each manufacturer shall provide or cause to be provided 

to the persons specified in paragraph (f)(2)(i) of this section and to any other interested 

parties a manufacturer-specific website containing the information specified in paragraph 

(f)(2)(i) of this section for vehicles identified in paragraph (f)(1) of this section that have 

been offered for sale; this requirement does not apply to indirect information, including 

the information specified in paragraphs (f)(12) through (f)(16) of this section. Each 

manufacturer website shall–

* * * * *

(6) * * *

(ii) * * *

(D) Any alternative means proposed by a manufacturer must be available to aftermarket 

technicians at a fair and reasonable price.

* * * * *

(7) * * *

(i) All information required to be made available by this section shall be made available 

at a fair and reasonable price. In determining whether a price is fair and reasonable, 

consideration may be given to relevant factors, including, but not limited to, the 

following:

* * * * *

(ii) * * *

(B) The Administrator will act on the request within 180 days following receipt of a 

complete request or following receipt of any additional information requested by the 

Administrator.

* * * * *

(10) * * *

(ii) Provide on the manufacturer’s website an index of all emissions-related training 

information available for purchase by aftermarket service providers for 1994 and newer 

vehicles. The required information must be made available for purchase within 3 months 

of model introduction and then must be made available at the same time it is made 

available to manufacturer-franchised dealerships, whichever is earlier. The index shall 

describe the title of the course or instructional session, the cost of the video tape or 

duplicate, and information on how to order the item(s) from the manufacturer website. 

All of the items available must be shipped within 24 hours of the order being placed and 

are to be made available at a fair and reasonable price as described in paragraph (f)(7) of 

this section. Manufacturers unable to meet the 24 hour shipping requirement under 

circumstances where orders exceed supply and additional time is needed by the 

distributor to reproduce the item being ordered may exceed the 24 hour shipping 

requirement, but in no instance can take longer than 14 days to ship the item.

* * * * *
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(13) Generic and enhanced information for scan tools. Manufacturers shall make 

available to equipment and tool companies all generic and enhanced service information 

including bi-directional control and data stream information as defined in paragraph 

(f)(2)(ii) of this section. This requirement applies for 1996 and later model year vehicles.

* * * * *

(iv) Manufacturers can satisfy the requirement of paragraph (f)(13)(iii) of this section by

making available diagnostic trouble trees on their websites in full text.

* * * * *

(16) * * *

(i) Manufacturers who have developed special tools to extinguish the malfunction 

indicator light (MIL) for Model Years 1994 through 2003 shall make available the 

necessary information to equipment and tool companies to design a comparable generic 

tool. 

* * * * *

(g) Through model year 2013, the manufacturer shall furnish or cause to be furnished to 

the purchaser the following statement for each new diesel-fueled Tier 2 vehicle (certified 

using a test fuel with 15 ppm sulfur or less): “This vehicle must be operated only with 

ultra low sulfur diesel fuel (that is, diesel fuel meeting EPA specifications for highway

diesel fuel, including a 15 ppm sulfur cap).”

§ 86.1808-07 [Removed]

172. Remove § 86.1808-07.

173. Section 86.1809-12 is amended by revising paragraph (c) introductory text to read 

as follows:

§ 86.1809-12 Prohibition of defeat devices.

* * * * *

(c) For cold temperature CO and cold temperature NMHC emission control, the 

Administrator will use a guideline to determine the appropriateness of the CO and 

NMHC emission control at ambient temperatures between 25 °F (the upper bound of the 

FTP test temperature range) and 68 °F (the lower bound of the FTP test temperature 

range). The guideline for CO emission congruity across the intermediate temperature 

range is the linear interpolation between the CO standard applicable at 25 °F and the CO 

standard applicable at 68 °F. The guideline for NMHC emission congruity across the 

intermediate temperature range is the linear interpolation between the NMHC FEL pass 

limit (e.g., 0.3499 g/mi for a 0.3 g/mi FEL) applicable at 20 °F and the Tier 2 NMOG 

standard or the Tier 3 NMOG+NOx bin standard to which the vehicle was certified at 68 

°F, where the intermediate temperature NMHC level is rounded to the nearest hundredth 

for comparison to the interpolated line. For vehicles that exceed this CO emissions 

guideline or this NMHC emissions guideline upon intermediate temperature testing:

* * * * *

174. Section 86.1810-01 is amended by removing and reserving paragraph (m), and 

revising paragraphs (f), (k)(3), and (o) to read as follows:
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§ 86.1810-01 General standards; increase in emissions; unsafe condition; waivers.

* * * * *

(f) Altitude requirements. Unless otherwise specified, emission standards apply at lowaltitude conditions and at high-altitude conditions. The following exceptions apply:

(1) The supplemental exhaust emission standards as described in § 86.1811–04(f) apply 

only at low-altitude conditions;

(2) The cold temperature NMHC emission standards as described in § 86.1811–10(g) 

apply only at low-altitude conditions;

(3) The evaporative emission standards specified in § 86.1811-09(e) apply at low-altitude 

conditions. The evaporative emission standards specified in § 86.1811-04(e) continue to 

apply at high-altitude conditions for 2009 and later model year vehicles. 

* * * * *

(k) * * *

(3) Refueling receptacle requirements. Compressed natural gas vehicles must meet the 

requirements for fueling connection devices as specified in § 86.1813-17(f)(1). 

* * * * *

(o) NMOG measurement procedures. Measure NMOG emissions using the procedures 

described in 40 CFR 1065.635.

* * * * *

175. A new § 86.1810-17 is added to subpart S to read as follows:

§ 86.1810-17 General requirements.

The following provisions apply to all vehicles certified under this subpart:

(a) Any device, system or element of design installed on or incorporated in a new motor 

vehicle to enable such vehicle to conform to the standards imposed by this subpart:

(1) Shall not in its operation or function cause the emission into the ambient air of any

noxious or toxic substance that would not be emitted in the operation of such vehicle 

without such system, except as specifically permitted by regulation; and

(2) Shall not in its operation, function or malfunction result in any unsafe condition 

endangering the vehicle, its occupants, or persons or property in close proximity to the 

vehicle.

(b) In establishing the physically adjustable range of each adjustable parameter on a new 

motor vehicle, the manufacturer shall ensure that, taking into consideration the 

production tolerances, safe vehicle drivability characteristics are available within that 

range.

(c) Unless otherwise specified, the emission standards of this subpart apply equally for 

certification and for in-use vehicles throughout the specified useful-life period. Also, 

manufacturers must use good engineering judgment to determine that all of a vehicle’s 

emission-related components are designed to operate properly throughout the specified 

useful-life period.

(d) Vehicles may not discharge crankcase emissions into the ambient atmosphere.

(e) All vehicles must have an onboard diagnostic system as described in § 86.1806.

(f) Emission standards apply at low-altitude conditions and at high-altitude conditions, 

except as noted in this subpart. 
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(g) The cold temperature CO and NMHC standards in this subpart refer to test procedures 

set forth in subpart C of this part and 40 CFR part 1066, subpart H. All other emission 

standards in this subpart rely on test procedures set forth in subpart B of this part. These 

procedures rely on the test specifications in 40 CFR parts 1065 and 1066 as described in 

subparts B and C of this part.

(h) Multi-fueled vehicles (including dual-fueled and flexible-fueled vehicles) must 

comply with all the requirements established for each consumed fuel (and blend of fuels 

for flexible-fueled vehicles). The following specific provisions apply for flexible-fueled 

vehicles that operate on ethanol and gasoline:

(1) For exhaust emissions, we may identify the worst-case fuel blend for testing in 

addition to what is required for gasoline-fueled vehicles. The worst-case fuel blend may

be the fuel specified in 40 CFR 1065.725, or it may consist of a combination of the fuels 

specified in 40 CFR 1065.710(b) and 1065.725. We may waive testing with the worstcase blended fuel for US06 and/or SC03 duty cycles; if we waive only SC03 testing, 

substitute the SC03 emission result using the standard test fuel for gasoline-fueled 

vehicles to calculate composite SFTP emissions.

(2) For refueling emissions, we may identify the worst-case fuel blend for testing in 

addition to what is required for gasoline-fueled vehicles. The worst-case fuel blend may

consist of a combination of the fuels specified in 40 CFR 1065.710(c) and 1065.725. 

This is generally expected to be a fuel blend with 10 percent ethanol and a nominal Dry

Vapor Pressure Equivalent of 10 psi. You may prepare such a worst-case fuel blend by

mixing it before dispensing into the vehicle’s fuel tank, or by consecutively dispensing 

appropriate amounts of the two specified fuels into a fuel tank.

(3) No additional spitback or evaporative emission testing is required beyond the 

emission measurements with the gasoline test fuel specified in 40 CFR 1065.710.

(i) Where we specify requirements based on a percentage of total sales volume in a given 

model year, you may instead ask us to calculate the percentage based on production 

volumes instead of sales volumes.

§ 86.1811-01 [Removed]

176. Remove § 86.1811-01.

177. Section 86.1811-04 is revised as follows:

a. By revising paragraph (e)(3)(i).

b. By removing and reserving paragraph (h).

c. By revising paragraphs (j), (n), and (o)(1) to read as follows:

§ 86.1811-04 – Emission standards for light-duty vehicles, light-duty trucks and 

medium-duty passenger vehicles.

* * * * *

(e) * * *

(3) * * *

(i) For gasoline-fueled and methanol-fueled LDV, LDT and MDPV: 0.20 grams 

hydrocarbon per gallon (0.053 grams per liter) of fuel dispensed. This standard also 

applies for diesel-fueled LDV.
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* * * * *

(j) Highway NOX exhaust emission standard. The NOx emissions measured on the federal 

Highway Fuel Economy Test in 40 CFR part 600, subpart B, must not be greater than 

1.33 times the applicable FTP NOx standard to which the manufacturer certifies the test 

group. Both the measured emissions and the product of the NOx standard and 1.33 must 

be rounded to the nearest 0.01 g/mi before being compared. 

* * * * *

(n) Requirements for vehicles with rechargeable energy storage systems. Manufacturers 

must measure emissions from hybrid electric vehicles (including plug-in hybrid electric 

vehicles) as described in 40 CFR part 1066, subpart F, except that these procedures do 

not apply for plug-in hybrid electric vehicles during charge-depleting operation. 

(o) * * *

(1) Manufacturers must measure NMOG emissions using the procedures described in 40 

CFR 1066.635.

* * * * *

178. A new § 86.1811-17 is added to subpart S to read as follows:

§ 86.1811-17 Exhaust emission standards for light-duty vehicles, light-duty trucks 

and medium-duty passenger vehicles.

(a) Applicability and general provisions. This section describes exhaust emission 

standards that apply for model year 2017 and later light-duty vehicles, light-duty trucks, 

and medium-duty passenger vehicles. MDPVs are subject to all the same provisions of 

this section that apply to LDT4. Some of the provisions of this section also apply to 

heavy-duty vehicles as specified in § 86.1816. See § 86.1818 for greenhouse gas 

emission standards. See § 86.1813 for evaporative and refueling emission standards. 

This section may apply to vehicles from model years earlier than 2017 as specified in 

paragraph (b)(11) of this section. 

(b) Tier 3 exhaust emission standards. Exhaust emissions may not exceed the Tier 3 

exhaust emission standards, as follows: 

(1) Measure emissions using the chassis dynamometer procedures of 40 CFR part 1066, 

as follows:

(i) Establish appropriate load settings based on loaded vehicle weight (see § 86.1803). 

(ii) Use appropriate driving schedules. Measurements involve testing over multiple 

driving schedules. The Federal Test Procedure (FTP) is based on testing with the Urban 

Dynamometer Driving Schedule (UDDS). The Supplemental Federal Test Procedure 

(SFTP) involves testing with the UDDS, the US06 driving schedule, and the SC03 

driving schedule. See 40 CFR 1066.801 for further information on these test cycles.

(iii) Calculate SFTP emissions as a composite of test results over the driving schedules 

identified in paragraph (b)(1)(ii) of this section based on the following calculation:

SFTP (g/mi) = 0.35∙FTP + 0.28∙US06 + 0.37∙SC03

(A) For test vehicles that do not have air conditioning, you may omit SC03 testing. To 

calculate composite SFTP emissions for such vehicles, use FTP emission results to 

substitute for the SC03 value in the equation. 
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(B) You may also use FTP emission results to substitute for the SC03 value in the 

equation for the types of vehicles identified in 40 CFR 600.115 that automatically qualify

for the derived 5-cycle method for determining fuel economy label values. Such vehicles 

remain subject to the SFTP standard when tested over the SC03 driving schedule. Other 

vehicles remain subject to the litmus-test provisions in 40 CFR 600.115.

(iv) Use E10 test fuel as required in § 86.113, except as specified in this section.

(v) Hydrocarbon emission standards are expressed as NMOG; however, for certain 

vehicles you may measure exhaust emissions based on nonmethane hydrocarbon instead 

of NMOG as described in 40 CFR 1066.635.

(vi) Measure emissions from hybrid electric vehicles (including plug-in hybrid electric 

vehicles) as described in 40 CFR part 1066, subpart F, except that these procedures do 

not apply for plug-in hybrid electric vehicles during charge-depleting operation.

(2) Table 1 of this section describes fully phased-in Tier 3 standards that apply as 

specified in this paragraph (b) for the identified driving schedules. The FTP standards for 

NMOG+NOx apply on a fleet-average basis using discrete bin standards as described in 

paragraph (b)(4) of this section. The bin standards include additional emission standards 

for high-altitude testing and for CO emissions when testing over the FTP driving 

schedule. The SFTP standards for NMOG+NOx apply on a fleet-average basis as 

described in paragraph (b)(5) of this section. Table 1 follows:

Table 1 of § 86.1811-17–

Fully Phased-in Tier 3 Exhaust Emission Standards (g/mile)

NMOG+NOx PM CO Formaldehyde

FTP1SFTP FTP US06 SFTP FTP

0.030 0.050 0.003 0.006 4.2 0.004

1 The fleet-average FTP emission standard for NMOG+NOx is 

0.026 g/mile for any LDV or LDT1 test group certified to standards 

based on a useful life of 120,000 miles or 10 years in a given model 

year.

(3) The FTP standards specified in this section apply for testing at low-altitude conditions 

and high-altitude conditions as specified in paragraph (b)(4) of this section. The SFTP 

standards specified in paragraph (b)(2) of this section apply only for testing at lowaltitude conditions. 

(4) The FTP emission standard for NMOG+NOx is based on a fleet average for a given 

model year. You must specify a family emission limit (FEL) for each test group. The 

FEL serves as the emission standard for the test group with respect to all required FTP 

testing. Calculate your fleet-average emission level as described in § 86.1860 based on 

the FEL that applies for low-altitude testing to show that you meet the specified standard. 

For multi-fueled vehicles, calculate fleet-average emission levels based only on emission 

levels for testing with gasoline or diesel fuel. You may generate emission credits for 

banking and trading and you may use banked or traded credits as described in § 86.1861 

for demonstrating compliance with the FTP emission standard for NMOG+NOx. You 
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comply with the emission standard for a given model year if you have enough credits to 

show that your fleet-average emission level is at or below the applicable standard. You 

may exchange FTP credits between or among any test groups subject to standards under 

this section. You may not exchange FTP and SFTP credits.

(i) Specify one of the identified values from Table 2 of this section as the FEL for 

demonstrating that your fleet-average emission level complies with the FTP emission 

standard for NMOG+NOx under low-altitude conditions. These FEL values define 

emission bins that also determine corresponding emission standards for NMOG+NOx 

emissions under high-altitude conditions, and for CO emissions, as follows:

Table 2 of § 86.1811-17—

Tier 3 FTP Bin Standards (g/mile)

FEL Name NMOG+NOx 

FELs for Low 

Altitude 

NMOG+NOx 

for High 

Altitude

CO for Low

and High 

Altitude

Bin 160 0.160 0.160 4.2

Bin 125 0.125 0.160 2.1

Bin 70 0.070 0.105 1.7

Bin 50 0.050 0.070 1.7

Bin 30 0.030 0.050 1.0

Bin 20 0.020 0.030 1.0

Bin 0 0.000 0.000 0.0

(ii) Manufacturers earn a compliance credit of 0.005 g/mile NMOG+NOx for vehicles 

that are certified for a useful life of 150,000 miles or 15 years and that are covered by an 

extended warranty over the same period for all components whose failure triggers MIL 

illumination. Manufacturers may apply the compliance credit as follows:

(A) You may reduce your official FTP emission result for certification by the amount of 

the compliance credit if that allows you to certify to a more stringent bin. In that case, 

you may use the more stringent bin standard for calculating the fleet-average 

NMOG+NOx emission level. For any compliance testing with these vehicles, the 

applicable FTP bin standard for NMOG+NOx is higher than the specified bin standard by 

the amount of the compliance credit. For example, if the official FTP emission result for 

NMOG+NOx is 0.052 g/mile, this qualifies for an FEL of 0.050 g/mile for calculating the 

fleet average and the vehicle is subject to an FTP bin standard of 0.055 g/mile. 

(B) If the amount of the compliance credit does not allow you to certify to a more 

stringent bin, calculate the fleet-average NMOG+NOx emission level using an FEL for 

these vehicles that is smaller than the bin standard by the amount of the compliance 

credit. For any compliance testing with these vehicles, the specified bin standard applies. 

For example, if the official FTP emission result for NMOG+NOx is 0.038 g/mile, 

calculate the fleet-average NMOG+NOx emission level by specifying an FEL of 0.045 

g/mile; these vehicles are subject to the specified FTP bin standard of 0.050 g/mile. 

(iii) If you qualify for a compliance credit for direct ozone reduction under the LEV III 

program, you may apply the compliance credit approved for California vehicles as 

described in paragraphs (b)(4)(ii)(A) and (B) of this section. 

(iv) You may combine the adjustments in paragraphs (b)(4)(ii) and (iii) of this section if 
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you qualify for them separately. 

(5) The SFTP emission standard for NMOG+NOx is also based on a fleet average in a 

given model year. You must specify FELs as described in paragraph (b)(4) of this 

section and calculate a fleet-average emission level to show that you meet the SFTP 

emission standard for NMOG+NOx, except that you may specify FELs in any even 

increment of 0.010 g/mile up to a maximum value of 0.180 g/mile. You may generate 

emission credits for banking and trading and you may use banked or traded credits as 

described in § 86.1861 for demonstrating compliance with the SFTP emission standard 

for NMOG+NOx. You comply with the emission standard for a given model year if you 

have enough credits to show that your fleet-average emission level is at or below the 

applicable standard. You may exchange SFTP credits between or among any test groups 

subject to standards under this section. You may not exchange FTP and SFTP credits. 

The SFTP standards described in this section apply only for testing at low-altitude 

conditions.

(6) The full Tier 3 program includes new emission standards for NMOG+NOx, PM, CO, 

and formaldehyde; it also includes measurement with a new test fuel and a longer useful 

life (for some vehicles). Vehicles meeting all these requirements are considered Final 

Tier 3 vehicles. Vehicles that do not meet all the Tier 3 requirements are considered 

Interim Tier 3 vehicles. Paragraphs (b)(7) through (13) of this section describe how to 

comply with standards during a phase-in period.

(7) The Tier 3 PM standards phase in over several years. The following provisions 

describe the primary approach for phasing in the Tier 3 PM standards:

(i) You must meet the FTP and the US06 PM standards with 20, 20, 40, 70, and 100 

percent of your projected nationwide sales of all vehicles subject to this section in model 

years 2017 through 2021, respectively. In model years 2017 and 2018, an interim US06 

PM standard of 0.010 g/mile applies. Each vehicle meeting the Tier 3 FTP standard for 

PM must also meet the Tier 3 US06 standard for PM. In model year 2017, the phase-in 

requirement applies only for vehicles at or below 6,000 pounds GVWR; however, you 

may meet an alternative phase-in requirement of 10 percent in model year 2017 based on 

your full production of vehicles subject to standards under this section. 

(ii) You may disregard the phase-in percentages specified in paragraph (b)(7)(i) of this 

section if you instead comply with an indexed PM phase-in schedule as described in this 

paragraph (b)(7)(ii). To do this, you must notify us of your intent before January 1, 2017, 

and include a detailed plan for complying with the indexed phase-in schedule. You 

comply with the indexed phase-in schedule by calculating a PM phase-in index at or 

above 540 using the following equation for model years 2017 through 2021:

PM phase-in index = 5∙APP2017 + 4∙APP2018 + 3∙APP2019 + 2∙APP2020 + APP2021

Where:

APP = The phase-in percentage of vehicles meeting the Tier 3 PM standards for the 

indicated model year, based on actual sales, as described in paragraph (b)(7)(i) of this 

section. 

(iii) Vehicles meeting the Tier 3 PM standards must meet those standards over the useful 

life as specified in § 86.1805. Note that Interim Tier 3 vehicles may have different useful 

life values for PM emission standards than for other emission standards.
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(iv) Any vehicles not included for demonstrating compliance with the Tier 3 PM phase-in 

requirement must instead comply with an FTP emission standard for PM of 0.010 g/mile, 

and a composite SFTP emission standard for PM of 0.070 g/mile.

(v) Measure PM emissions from all vehicles using the same test fuel specified in 

paragraph (b)(8) of this section for measuring NMOG+NOx emissions. 

(vi) You may certify Interim Tier 3 vehicles based on carryover data.

(vii) You may use the alternative phase-in provisions described in paragraph (b)(9) of this 

section to transition to the Tier 3 exhaust emission standards on a different schedule. 

(8) The following provisions describe the primary approach for phasing in the Tier 3 

standards other than PM in 2025 and earlier model years:

(i) FTP phase-in. The fleet-average FTP emission standard for NMOG+NOx phases in 

over several years as described in this paragraph (b)(8)(i). You must identify FELs as 

described in paragraph (b)(4) of this section and calculate a fleet-average emission level 

to show that you meet the FTP emission standard for NMOG+NOx that applies for each 

model year. For model year 2017, do not include vehicles above 6,000 pounds GVWR. 

Through model year 2019, you may also certify to transitional Bin 85 or Bin 110 

standards, which consist of all-altitude FTP emission standards for NMOG+NOx of 

0.085 or 0.110 g/mile, respectively; additional FTP standards for PM, CO, and 

formaldehyde apply as specified in this section for vehicles certified to Bin 125 

standards. Fleet-average FTP emission standards decrease through the phase-in period 

as shown in the following table:

Table 3 of § 86.1811-17—

Declining Fleet-Average Tier 3 FTP 

Emission Standards for NMOG+NOx (g/mile)

Model Year LDV, LDT11 LDT2, HLDT

2017 20.086 0.101

2018 0.079 0.092

2019 0.072 0.083

2020 0.065 0.074

2021 0.058 0.065

2022 0.051 0.056

2023 0.044 0.047

2024 0.037 0.038

2025 0.030 0.030

1 Calculate the adjusted fleet-average standard for LDV and 

LDT1 test groups certified to standards based on a useful life of 

120,000 miles or 10 years in a given model year by multiplying 

the specified value by 0.85 and rounding to the nearest 0.001 

g/mile. Through model year 2019, apply this adjustment only if 

one or more test groups is certified to Bin 70 or lower standards 

based on a useful life of 120,000 miles or 10 years.

2 Vehicles above 6,000 pounds GVWR must meet the Tier 3 

standards starting with model year 2018.

(ii) SFTP phase-in. The fleet-average SFTP emission standard for NMOG+NOx phases 

in over several years as described in this paragraph (b)(8)(ii). You must identify FELs as
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described in paragraph (b)(5) of this section and calculate a fleet-average emission level 

to show that you meet the SFTP emission standard for NMOG+NOx that applies for each 

model year. 

(A) Calculate the fleet-average emission level together for all your light-duty vehicles 

and light-duty trucks, except for those certified using the provisions of paragraph 

(b)(8)(ii)(C) of this section. For model year 2017, do not include vehicles above 6,000 

pounds GVWR (in the numerator or denominator). 

(B) Fleet-average FTP emission standards decrease through the phase-in period as shown 

in the following table:

Table 4 of § 86.1811-17—

Declining Fleet-Average Tier 3

SFTP Emission Standards 

Model

Year

NMOG+NOx 

(g/mile)

201710.103

2018 0.097

2019 0.090

2020 0.083

2021 0.077

2022 0.070

2023 0.063

2024 0.057

2025 0.050

1 Vehicles above 6,000 pounds GVWR 

must meet the Tier 3 standards starting 

with model year 2018.

(C) You may use the Option 1 provisions specified in the LEV III program to 

demonstrate compliance with EPA’s SFTP standards. Do not include any such test 

groups when demonstrating compliance with the phased-in fleet-average SFTP standards 

specified in this paragraph (b)(8)(ii). Note that this option is not available for vehicles 

certified to the transitional bins described in paragraph (b)(8)(i) of this section.

(iii) Interim provisions. (A) For LDT2 and HLDT certified to bins higher than Bin 70 

under this section through model year 2019, the Tier 2 useful life period applies as 

specified in § 86.1805-12 for all criteria pollutants other than PM. A similar provisions 

applies for LDV and LDT1, as described in Table 3 of this section.

(B) You may use the E0 test fuel specified in § 86.113 through model year 2019 for 

gasoline-fueled vehicles certified to bins higher than Bin 70. You may not certify these 

vehicles using carryover data after model year 2019.

(iv) You may use the alternative phase-in provisions described in paragraph (b)(9) of this 

section to transition to the Tier 3 exhaust emission standards on a different schedule. 

(9) This paragraph (b)(9) describes an alternative approach to phasing in the Tier 3 

emission standards for vehicles above 6,000 pounds GVWR. If you choose this 

approach, you must phase in the Tier 3 standards for all your vehicles above 6,000 

pounds GVWR that are subject to this section according to this schedule. Under this 
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alternative phase-in, you must meet the fully phased-in standards specified in this 

paragraph (b) with 40, 70, and 100 percent of your projected nationwide sales of all 

vehicles above 6,000 pounds GVWR that are subject to this section in model years 2019 

through 2021, respectively. Any vehicles not subject to Tier 3 standards during the 

phase-in period must continue to comply with the Tier 2 standards in § 86.1811-04(c) and 

(f), including the Tier 2 SFTP emission standards for NMHC+NOx and CO for 4,000-

mile testing as specified in § 86.1811-04(f)(1). Vehicles subject to Tier 2 standards under 

this paragraph (b)(9) are subject to the useful life provisions in § 86.1805-12 relative to 

exhaust emission standards. Each vehicle counting toward the phase-in percentage under 

this paragraph (b)(9) must meet all the standards that apply throughout the useful life as 

specified in § 86.1805-17, and must use the Tier 3 test fuel specified in § 86.113-07. The 

following exceptions and special provisions apply under this paragraph (b)(9):

(i) For model year 2019, you may exclude from the phase-in calculation any test groups 

with vehicles above 6,000 pounds GVWR that have a Job 1 date on or before [INSERT 

DATE FOUR YEARS AFTER FRM SIGNATURE] (see 40 CFR 85.2304).

(ii) The FTP and SFTP emission standards for NMOG+NOx are fleet-average standards. 

Calculate your fleet-average values based on all the vehicles that are subject to the 

standard in a given year. You may not generate credits for banking or trading in model 

years 2019 or 2020, and you may not use banked or traded credits to demonstrate 

compliance with the standards in those years. 

(iii) The US06 emission standard for PM is 0.010 g/mile in model years 2019 through 

2021, and 0.006 g/mile starting in model year 2022. The other standards described in this 

paragraph (b)(9) apply to all your vehicles above 6,000 pounds GVWR in model years 

2022 through 2024. 

(10) You may not use credits generated from Tier 2 vehicles for demonstrating 

compliance with the Tier 3 standards except as specified in this paragraph (b)(10). You 

may generate early credits with U.S. sales of Tier 2 vehicles in the two model years 

before the Tier 3 standards start to apply for a given vehicle model. Vehicles certified to 

the Tier 2 standards must meet all the Tier 2 requirements in § 86.1811-10, including the 

fleet-average Tier 2 standards. Calculate early Tier 3 emission credits as described in § 

86.1861 by subtracting the appropriate Tier 2 fleet-average value for FTP emissions of 

NMOG+NOx from 0.160 g/mile. Calculate your fleet-average value for the model year 

based on vehicles at or below 6,000 pounds GVWR in 2015, on all sizes of vehicles in 

2016, and on vehicles above 6,000 pounds GVWR in 2017. You may use these early

credits as described in § 86.1861 for demonstrating compliance with the FTP emission 

standard for NMOG+NOx starting in model year 2017. For model years 2018 and later, 

you may use these early credits for banking or trading subject to a limitation based on 

credits generated in California, as follows:

(i) For the applicable model years in which you generate emission credits relative to 

California’s LEV III fleet-average NMOG+NOx standard, determine the actual 

California sales of light-duty vehicles and light-duty trucks and the actual nationwide 

sales of those same vehicles. In 2015, count sales only from vehicle models at or below 

6,000 pounds GVWR. For each model year, multiply the credits generated under the 

California program by the ratio of nationwide vehicle sales to LEV III vehicle sales to 
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calculate an effective nationwide quantity. Sum these results for model years 2015 

through 2017. Note that this calculation results in a maximum credit quantity based on 

vehicle sales in all states, even though the initial credit calculation does not include 

vehicle sales in California or the section 177 states. If you comply with the LEV III 

standards based on pooled emission credits for California and the section 177 states, use 

those pooled emission credits and corresponding sales for calculating the maximum 

credit quantity under this paragraph (b)(10)(i). 

(ii) You may not use more early credits generated under this paragraph (b)(10) for 

banking or trading to demonstrate compliance with Tier 3 emission standards than the 

calculated value of the effective nationwide credit quantity summed in paragraph 

(b)(10)(i) of this section. If your generated credits are greater than this threshold, 

determine the percentage of your generated early credits that exceed the threshold. 

Calculate an adjusted quantity of early credits generated under this paragraph (b)(10) by 

decreasing the generated quantity from each model year by the calculated percentage that 

exceed the applicable threshold. This adjusted quantity of credits may be used for 

banking or trading relative to the Tier 3 standards, subject to the five-year credit life 

described in § 86.1861. 

(11) You may certify vehicles to the Tier 3 standards starting in model year 2015. To do 

this, you may either sell all your LEV III vehicles models nationwide, or you may certify

a subset of your fleet to alternate fleet-average emission standards as follows:

(i) The alternate fleet-average FTP emission standards for NMOG+NOx are 0.100 g/mile 

in 2015 and 0.093 g/mile in 2016 for LDV and LDT1. 

(ii) The alternate fleet-average FTP emission standards for NMOG+NOx are 0.119 g/mile 

in 2015, 0.110 g/mile in 2016, and 0.101 g/mile in 2017 for LDT2 and HLDT. 

(iii) The alternate fleet-average SFTP emission standards for NMOG+NOx are 0.140 in 

2015 for LDV and LDT1, 0.110 in 2016 for all vehicles, and 0.103 in 2017 for LDT2 and 

HLDT. 

(iv) The vehicles must meet FTP and SFTP standards for PM as specified in § 86.1811-

04. The PM testing provisions of § 86.1829-01(b)(1)(iii)(B) apply for these vehicles.

(v) Vehicles not certified to the Tier 3 standards in a given model year must meet all the 

requirements that apply for Tier 2 vehicles in that model year.

(vi) For cold temperature testing and for high-altitude testing, you may use the E0 fuel 

specified in § 86.113-04(a) or § 86.213 instead of the E10 test fuel specified in § 86.113-

07.

(vii) For vehicles certified under this paragraph (b)(11), you may generate emission 

credits and use those credits for demonstrating compliance with Tier 3 standards as 

described in paragraph (b)(10) of this section. 

(12) The following alternate standards apply for in-use testing:

(i) Alternate in-use FTP standards for NMOG+NOx apply for 2021 and earlier model 

year vehicles certified to Bin 70 and lower. Calculate these alternate standards by

multiplying the applicable FEL by 1.4. These alternate standards apply only for testing at 

low-altitude conditions.

(ii) The alternate in-use FTP standard for PM is 0.006 g/mile for 2021 and earlier model 

year vehicles. 
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(iii) The in-use US06 standard for PM is 0.010 g/mile for 2023 and earlier model year 

vehicles.

(13) Keep records as needed to show that you meet the requirements specified in this 

paragraph (b) for phasing in standards and for complying with declining fleet-average 

average standards.

(c) Highway NMOG+NOx exhaust emission standard. NMOG+NOx emissions measured 

on the federal Highway Fuel Economy Test in 40 CFR part 600, subpart B, may not 

exceed the applicable FTP bin standard for NMOG+NOx. Demonstrate compliance with 

this standard for low-mileage vehicles by applying the appropriate deterioration factor. 

For vehicles not certified to any Tier 3 emission standards specified in paragraph (b) of 

this section, the provisions of § 86.1811-04(j) apply instead of this paragraph (c). 

(d) Special provisions for Otto-cycle engines. The special provisions described in this 

paragraph (d) apply for vehicles with Otto-cycle engines. For vehicles not certified to 

any Tier 3 emission standards, the provisions of § 86.1810-01(i)(6), (i)(13), and (i)(14) 

apply instead of this paragraph (d).

(1) Enrichment limits. The nominal air-fuel ratio throughout the US06 cycle may not be 

richer than the leanest air-fuel mixture required for lean best torque, except as allowed 

under paragraph (d)(2) of this section. Unless we approve otherwise in advance, lean 

best torque is the leanest air-fuel ratio required at any speed and load point with a fixed 

spark advance to make peak torque. The allowable tolerance around the nominal value 

for any given speed and load point over the US06 cycle for a particular vehicle is 4 

percent, which is calculated as the nominal mass-based air-fuel ratio for lean best torque 

divided by 1.04. 

(2) Engine protection. AECDs that use commanded enrichment to protect the engine or 

emission control hardware must not use enrichment more frequently or to a greater 

degree than is needed for this purpose. For purposes of this section, commanded 

enrichment includes intended engine operation at air-fuel ratios rich of stoichiometry, 

except the following:

(i) Cycling back and forth in a narrow window between rich and lean operation as a result 

of feedback controls targeted to maintain overall engine operation at stoichiometry.

(ii) Small changes in the target air-fuel ratio to optimize vehicle emissions or drivability. 

This may be called “closed-loop biasing.”

(iii) Temporary enrichment in response to rapid throttle motion.

(iv) Enrichment during cold-start and warm-up conditions.

(v) Temporary enrichment for running OBD checks to comply with § 86.1806.

(3) A/C-on specific calibrations. (i) A/C-on specific calibrations (e.g., air-fuel ratio, spark 

timing, and exhaust gas recirculation) that differ from A/C-off calibrations may be used 

for a given set of engine operating conditions (e.g., engine speed, manifold pressure, 

coolant temperature, air charge temperature, and any other parameters). Such 

calibrations must not unnecessarily reduce emission control effectiveness during A/C-on 

operation when the vehicle is operated under conditions that may reasonably be expected 

during normal operation and use. If emission control effectiveness decreases as a result 

of such calibrations, the manufacturer must describe in the Application for Certification 

the circumstances under which this occurs and the reason for using these calibrations.
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(ii) For AECDs involving commanded enrichment, these AECDs must not operate 

differently for A/C-on operation than for A/C-off operation, except as provided under 

paragraph (d)(2) of this section. This includes both the sensor inputs for triggering 

enrichment and the degree of enrichment employed. 

(4) “Lean-on-cruise” calibration strategies. Manufacturers may use “lean-on-cruise” 

strategies subject to the following specifications:

(i) A “lean-on-cruise” strategy is defined as the use of an air-fuel ratio significantly leaner 

than stoichiometry during non-deceleration conditions at speeds above 40 mph.

(ii) You must not employ “lean-on-cruise” strategies during vehicle operation in normal 

driving conditions, including A/C usage, unless at least one of the following conditions is 

met:

(A) Such strategies are substantially employed during the FTP, US06, or SC03 duty

cycle.

(B) Such strategies are demonstrated not to significantly reduce vehicle emission control 

effectiveness over the operating conditions in which they are employed.

(C) Such strategies are demonstrated to be necessary to protect the vehicle occupants, 

engine, or emission control hardware.

(iii) If you propose to use a “lean-on-cruise” strategy, you must describe in the 

application for certification the circumstances under which such a calibration would be 

used and the reasons for using it.

(e) through (f) [Reserved]

(g) Cold temperature exhaust emission standards. The following standards apply for 

vehicles tested over the test procedures specified in subpart C of this part:

(1) Cold temperature CO standards. These cold temperature CO standards are applicable 

only to gasoline-fueled vehicles. These standards apply for testing at low-altitude 

conditions and high-altitude conditions. Cold temperature CO exhaust emission 

standards apply when measured using the test procedures specified in subpart C of this 

part, as follows:

(i) For LDV and LDT1, the standard is 10.0 g/mile CO.

(ii) For LDT2, LDT3 and LDT4, the standard is 12.5 grams per mile CO.

(2) Cold temperature NMHC standards. Fleet average cold temperature NMHC standards 

are applicable only to gasoline-fueled vehicles, and apply equally to certification and inuse except as otherwise specified in § 86.1811-10(u) for in-use standards for applicable 

phase-in models. Testing with other fuels such as a high-level ethanol-gasoline blend, or 

testing on diesel vehicles, is not required. Multi-fuel, bi-fuel or dual-fuel vehicles must 

comply with requirements using gasoline only. 

(i) The standards are shown in the following table:
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Table 5 of § 86.1811-17—Fleet Average Cold Temperature 

NMHC Exhaust Emission Standards

Vehicle weight category Cold temperature NMHC 

sales-weighted fleet average 

standard (g/mile)

LDV and LLDT 0.3

HLDT 0.5

(ii) The manufacturer must calculate its fleet average cold temperature NMHC emission 

level(s) as described in § 86.1864–10(m).

(iii) The standards specified in this paragraph (g)(2) apply only for testing at low-altitude 

conditions. However, manufacturers must submit an engineering evaluation indicating 

that common calibration approaches are utilized at high altitudes. Any deviation from 

low altitude emission control practices must be included in the auxiliary emission control 

device (AECD) descriptions submitted at certification. Any AECD specific to high 

altitude must require engineering emission data for EPA evaluation to quantify any 

emission impact and validity of the AECD.

(h) Small-volume manufacturers. Small-volume manufacturers may use the following 

Tier 3 phase-in provisions: 

(1) Instead of the fleet-average FTP standards for NMOG+NOx specified in this section, 

small-volume manufacturers may meet alternate fleet-average standards of 0.125 g/mile 

through model year 2021, and 0.051 g/mile for model years 2022 through 2027. The 

following additional provisions apply for vehicles certified under this paragraph (h)(1):

(i) Vehicles are subject to exhaust emission standards over the useful life as specified in § 

86.1805-12 through model year 2021, and as specified in this section starting in model 

year 2022.

(ii) Gasoline-fueled vehicles may use the E0 test fuel specified in § 86.113-04 for 

vehicles certified to bins higher than Bin 70 through model year 2021.

(iii) Vehicles certified under this paragraph (h)(1) may generate emission credits and they

may use banked or traded emission credits relative to the alternate fleet-average FTP 

standard for NMOG+NOx only in model years 2022 through 2027. 

(iv) Vehicles are subject to all the other requirements specified in this section. 

(2) Small-volume manufacturers may delay complying with all the requirements of this 

section until model year 2022, and instead meet all the requirements that apply to Tier 2 

vehicles under § 86.1811-10 for 2021 and earlier model years. 

(3) If meeting the Tier 3 standards would cause severe economic hardship, small-volume 

manufacturers may ask us to approve an extended compliance deadline under the 

provisions of 40 CFR 1068.250, except that the solvency criterion does not apply and 

there is no maximum duration of the hardship relief. 

§§ 86.1812-01 and 86.1813-01 [Removed]

179. Remove §§ 86.1812-01 and 86.1813-01.

180. A new § 86.1813-17 is added to subpart S to read as follows:

§ 86.1813-17 Evaporative and refueling emission standards.
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Vehicles must meet evaporative and refueling emission standards as specified in this 

section. These standards apply for heavy duty vehicles above 14,000 pounds GVWR as 

specified in § 86.1801. The emission standards apply for total hydrocarbon equivalent 

(THCE) measurements using the test procedures specified in subpart B of this part, as 

appropriate. Note that § 86.1829 allows you to certify without testing in certain 

circumstances. Except as specified in paragraph (b) of this section, evaporative and 

refueling emission standards do not apply for diesel-fueled vehicles. Unless otherwise 

specified, MDPVs are subject to all the same provisions of this section that apply to 

LDT4.

(a) Tier 3 evaporative emission standards. Vehicles may not exceed the Tier 3 

evaporative emission standards, as follows:

(1) Measure emissions using the test procedures of subpart B of this part, as follows:

(i) Follow the vehicle preconditioning and exhaust testing procedures as described in 

subpart B of this part.

(ii) Measure diurnal, running loss, and hot soak emissions as shown in § 86.130. This 

includes separate measurements for the two-diurnal test sequence and the three-diurnal 

test sequence; however, gaseous-fueled vehicles are not subject to evaporative emission 

standards using the two-diurnal test sequence.

(iii) For gasoline-fueled vehicles, use E10 test fuel as required in § 86.113, except as 

specified in this section.

(iv) Emissions are generally measured with a flame ionization detector (FID). In the case 

of diurnal, hot soak, and running loss testing with E10 test fuel, multiply measured 

(unspeciated) FID values by 1.08 to account for the FID’s reduced response to ethanol. 

You may instead determine total hydrocarbon equivalent for E10 testing based on 

speciated measurements as described in § 86.143-96(c). You must use the same method 

(with or without speciation) for all of the specified evaporative testing for a given 

evaporative/refueling family. Similarly, any evaporative/refueling families certified in 

later model years using carryover data must use the same method that was used for the 

original testing. We may do testing with or without speciation, but we will apply the 1.08 

correction factor to unspeciated measurements only if you also use it to determine your 

final test results.

(2) Diurnal and hot soak emissions may not exceed the Tier 3 emission standards, as 

follows:

(i) The emission standard for the sum of diurnal and hot soak measurements from the 

two- diurnal test sequence and the three- diurnal test sequence is based on a fleet average 

in a given model year. You must specify a family emission limit (FEL) for each 

evaporative family. The FEL serves as the emission standard for the evaporative family 

with respect to all required diurnal and hot soak testing. Calculate your fleet average 

emission level as described in § 86.1860 based on the FEL that applies for low-altitude 

testing to show that you meet the specified standard. For multi-fueled vehicles, calculate 

fleet-average emission levels based only on emission levels for testing with gasoline. 

You may generate emission credits for banking and trading and you may use banked or 

traded credits for demonstrating compliance with the diurnal plus hot soak emission 

standard for vehicles required to meet the Tier 3 standards, other than electric vehicles 
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and gaseous-fueled vehicles, as described in § 86.1861 starting in model year 2017. You 

comply with the emission standard for a given model year if you have enough credits to 

show that your fleet-average emission level is at or below the applicable standard. You 

may exchange credits between or among evaporative families within an averaging set as 

described in § 86.1861. Separate diurnal plus hot soak emission standards apply as 

shown for high-altitude conditions. The sum of diurnal and hot soak measurements may

not exceed the following fleet-average Tier 3 standards:

Table 1 of § 86.1813-17—

Tier 3 Diurnal Plus Hot Soak Emission Standards (grams per test)

Vehicle category Low-altitude 

conditions

High-altitude 

conditions

LDV, LDT1 0.300 0.65

LDT2 0.400 0.85

HLDT 0.500 1.151

HDV 0.600 1.75

1

1.25 g/test for MDPVs.

(ii) Specify FELs as follows:

(A) You may specify the low-altitude FEL in increments of 0.025 g above or below the 

otherwise applicable Tier 3 diurnal plus hot soak standard, up to the maximum values 

specified in the following table:

Table 2 of § 86.1813-17—

Tier 3 FEL Caps for Low-Altitude Testing

Vehicle category FEL caps

LDV 0.500

LLDT 0.650

HLDT 0.900

MDPV 1.000

HDV 1.4

(B) Calculate the FEL for testing at high-altitude conditions based on the difference 

between the low-altitude FEL and the standard. For example, if a light-duty vehicle was 

certified with an FEL of 0.400 g instead of the 0.300 g standard, the FEL for testing 

under high-altitude conditions would be 0.75 g (0.65+0.10). 

(iii) Hydrocarbon emissions must not exceed 0.020 g for LDV and LDT and 0.030 g for 

HDV when tested using the Bleed Emission Test Procedure adopted by the California Air 

Resources Board as part of the LEV III program. This procedure quantifies diurnal 

emissions without measuring hot soak emissions. The standards in this paragraph 

(a)(2)(iii) do not apply for testing at high-altitude conditions. For vehicles with nonintegrated refueling canisters, the bleed emission test and standard do not apply to the 

refueling canister. You may perform the Bleed Emission Test Procedure using the 

analogous test temperatures and the E10 test fuel specified in subpart B of this part.

(3) Running losses may not exceed 0.05 g per mile when measured using the test 

procedures specified in § 86.134. This standard does not apply for gaseous-fueled 
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vehicles.

(4) Fuel systems for vehicles operating on one or more volatile liquid fuels may not 

exceed an effective leak diameter of 0.02 inches when measured using the procedure 

specified in 40 CFR 1066.985. For vehicles with fuel tanks exceeding 25 gallons 

nominal fuel tank capacity, you may request our approval for a leak standard greater than 

0.020 inches, up to a maximum value of 0.040 inches. 

(5) The Tier 3 evaporative emission standards start to phase in with model year 2017 for 

vehicles at or below 6,000 pounds GVWR and with model year 2018 for vehicles above 

6,000 pounds GVWR. Table 3 of this section specifies the minimum percentage of each 

manufacturer’s sales in each model year that must be certified to the Tier 3 evaporative 

emission standards. Calculate annual percentages based on actual nationwide sales of all 

vehicles subject to standards under this paragraph (a) for the applicable model year; 

however, if all your FELs for Tier 3 evaporative families are at the applicable standard 

(neither generating nor using emission credits), the phase-in requirements are based on 

projected sales. Also, if you certify vehicles above 6,000 pounds GVWR to the Tier 3 

evaporative emission standards in model year 2017, you may count projected U.S. sales 

of those vehicles toward your calculation for meeting the 40 percent requirement in 2017 

(numerator only). Manufacturers may meet this requirement using the additional 

alternative phase-in provisions in paragraph (g) of this section. Vehicles from the 

identified model years not certified to the Tier 3 evaporative emission standards continue 

to be subject to the evaporative emission standards specified in § 86.1811-09(e) or 

§ 86.1816-08(d) , including the useful life provisions of § 86.1805-12. Note that this 

subjects LDV and LDT1 to a 150,000 mile useful life for evaporative emissions if the 

vehicles are subject to a 150,000 mile useful life for exhaust emissions. Keep records as 

needed to show that you meet the phase-in requirements specified in this section. See 

paragraph (g) of this section for additional provisions that apply for model year 2017 and 

the rest of the phase-in. 

Table 3 of § 86.1813-17—

Default Phase-in Schedule for Tier 3 

Evaporative Emission Standards

Model year Minimum percentage of vehicles 

subject to the Tier 3 standards

2017 40%1,2

2018 60%

2019 60%

2020 80%

2021 80%

2022 100%

1 The phase-in percentage for model year 2017 applies 

only for vehicles at or below 6,000 pounds GVWR.

2 The leak standard specified in paragraph (a)(4) of this 

section does not apply for model year 2017.
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(6) For model year 2017, exclude vehicle sales from California and section 177 states 

from the calculation to demonstrate compliance with the phase-in schedule in paragraph 

(a)(5) or (g) of this section, and from the credit calculation in § 86.1860. 

(b) Refueling emissions. Light-duty vehicles, light-duty trucks, and complete heavy-duty 

vehicles must meet the refueling emission standards in this paragraph (b) when measured

over the procedure specified in § 86.150. These standards apply starting with model year 

2018 for vehicles above 10,000 pounds GVWR. The following refueling standards 

apply:

(1) 0.20 g THCE per gallon of fuel dispensed for vehicles using volatile liquid fuels. 

This standard also applies for diesel-fueled LDV.

(2) 0.15 g THC per gallon of fuel dispensed for liquefied petroleum gas-fueled vehicles 

and natural gas-fueled vehicles. 

(c) Fuel spitback. For vehicles fueled by volatile liquid fuels, fuel spitback emissions 

may not exceed 1.0 g THCE when measured using the test procedures specified in § 

86.146. The fuel spitback standard applies only to newly assembled vehicles. 

(d) [Reserved]

(e) Auxiliary engines and separate fuel systems. The provisions of 40 CFR 1037.103(g) 

apply for vehicles with auxiliary engines. This includes any engines installed in the final 

vehicle configuration that contribute no motive power through the vehicle’s transmission.

(f) Refueling provisions for gaseous-fueled vehicles. The following provisions apply

specifically for gaseous-fueled vehicles:

(1) Compressed natural gas vehicles must meet the requirements for fueling connection 

devices as specified in ANSI NGV1-2006 (incorporated by reference in § 86.1). 

(2) [Reserved]

(3) With our advance approval, liquefied petroleum gas-fueled vehicles with gauges or 

valves that can be opened to release fuel or fuel vapor during refueling (such as fixed 

liquid level gauges) may be tested for refueling emissions without opening such gauges 

or valves, as outlined in § 86.157–98(d)(2). We will approve your request if you can 

show that such gauges or valves will not be open during in-use refueling due to 

inaccessibility or other design features that would prevent them from opening or make 

this very unlikely.

(g) Alternative phase-in options for Tier 3 evaporative emission standards. You may use 

any of the following alternative methods to transition to the Tier 3 evaporative emission 

standards:

(1) Starting in model year 2015, you may earn an “allowance” for each vehicle that you 

certify early under this paragraph (g)(1). For each allowance you earn, you may count it 

as one compliant vehicle in a later model year during the phase-in period. Calculate the 

total phase-in percentage in each model year by adding the allowances to the number of 

compliant vehicles (in the numerator), without increasing total sales (in the denominator). 

For each allowance you earn, you may alternatively count it as one compliant vehicle 

under the phase-in schedule described in paragraph (g)(5) of this section, except that you 

may not use those allowances to increase the value of the phase-in index from any model 

year by more than 10 percentage points. Vehicles earning allowances under this 

paragraph (g)(1) may not have an FEL above the applicable Tier 3 standard, and may not 
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generate emission credits for banking or trading. Allowances may not be traded to 

another company. You may earn allowances under this paragraph (g)(1) for earlycompliant vehicles as follows:

(i) Model year 2015 and 2016 vehicles at or below 6,000 pounds GVWR meeting the 

Tier 3 standards in paragraph (a) of this section or the equivalent California standards as 

specified in paragraph (g)(4) of this section earn allowances, as long as the vehicles are 

not sold in California or any of the section 177 states. 

(ii) Model year 2015 through 2017 LDV and LDT above 6,000 pounds GVWR meeting 

the Tier 3 standards in paragraph (a) of this section or the equivalent California standards 

as specified in paragraph (g)(4) of this section earn allowances, as long as the vehicles are 

not sold in California or any of the section 177 states. 

(iii) Model year 2015 through 2017 MDPV and HDV meeting the Tier 3 standards in 

paragraph (a) of this section or the equivalent California standards as specified in 

paragraph (g)(4) of this section earn allowances for vehicles sold in any state.

(iv) To the extent that you over-comply with the 40-percent phase-in requirement in 

model year 2017, you may count your actual U.S. sales exceeding the required number of 

Tier 3 vehicles as allowances toward meeting the phase-in requirement in 2018 and later 

model years.

(v) For HDV above 10,000 pounds GVWR and at or below 14,000 pounds GVWR that 

you certify to the refueling emission standards in paragraph (b) of this section in model 

years 2015 through 2017 and sell outside of California and the section 177 states, a single 

vehicle may produce two allowances if it is certified to the Tier 3 diurnal plus hot soak 

standard. Allowances earned under this paragraph (g)(1)(v) may alternatively be used in 

model years 2018 through 2022 to phase in the refueling standard, except that a single 

early-compliant vehicle produces only a single allowance.

(vi) Complete HDV above 14,000 pounds GVWR and all sizes of incomplete HDV earn 

allowances as described in paragraph (g)(1)(v) of this section if they are certified to the 

refueling emission standards in paragraph (b) of this section in model years 2015 through 

2021.

(2) The following alternative phase-in options apply for model year 2017:

(i) You may disregard the percentage phase-in specified in paragraph (a)(5) of this 

section for 2017 if you choose 50-state certification for all your vehicles meeting the 

LEV III PZEV evaporative standards in 2017. Under this option, you may not produce a 

higher-emitting version of those vehicle models for sale outside of California or the 

section 177 states. Such vehicles may be certified using carryover data under the 

California program, but they may not generate or use emission credits. LDV and LDT1 

that comply under this paragraph (g)(2)(i) may not generate allowances under paragraph 

(g)(1) of this section, regardless of the calculated percentage of compliant vehicles in 

model year 2017.

(ii) You may comply with the phase-in requirement for model year 2017 by meeting the 

Tier 3 emission standards for diurnal plus hot soak, running loss, and bleed emissions (or 

the equivalent set of California standards as allowed in this section) with 20 percent of 

vehicles at or below 6,000 pounds GVWR, and by meeting the leak standard in paragraph 

(a)(2)(iii) of this section with 20 percent of vehicles at or below 6,000 pounds GVWR. 
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You may optionally include vehicles above 6,000 pounds GVWR under this paragraph 

(g)(2)(ii) to calculate the percentage (numerator only) if they meet the leak and/or 

evaporative emission standards in model year 2017. Vehicles complying with Tier 3 

evaporative emission standards may generate or use emission credits relative to the 

diurnal plus hot soak standard as specified in this section, but they may not generate 

allowances. You may apply this option and use the alternative phase-in calculation in 

paragraph (g)(4) of this section, subject to the following conditions:

(A) You must meet or exceed the 20 percent threshold for both evaporative emissions and 

the leak standard.

(B) All the vehicles meeting the leak standard must also meet the Tier 3 evaporative 

emission standards and the OBD requirements in § 86.1806-17(b)(1).

(C) Determine the appropriate percentage for calculating compliance under paragraph 

(g)(4) of this section by adding 20 to the percentage of vehicles meeting the Tier 3 

evaporative emission standards to account for vehicles meeting the leak standard. Do not 

increase the percentage based on meeting the leak standard with more than 20 percent of 

your vehicles in model year 2017.

(3) If you certify model year 2021 or earlier vehicles to the LEV III evaporative emission 

standards in California, you may certify those as Tier 3 vehicles that count toward 

meeting the phase-in requirements of this section. Such vehicles must still be certified to 

the high-altitude standards in paragraph (a)(2) of this section and the leak standard 

specified in paragraph (a)(4) of this section. You may not certify vehicles under this 

paragraph (g)(3) after model year 2021. Vehicles meeting the LEV III standards may

also generate allowances under paragraph (g)(1) of this section; however, these vehicles 

may generate or use emission credits under this subpart only if they are not used to 

generate allowances and if they are certified using the Option 2 procedures under the 

LEV III program (including the bleed emission test). Vehicles may be certified under 

this paragraph (g)(3) based on the rig test (“Option 1”) if they are certified to LEV III 

standards based on the rig test before model year 2017; this certification option applies 

through model year 2021. Include these Option 1 vehicles in the calculation of fleet 

average emissions by using the appropriate Tier 3 emission standard as the FEL. Note 

that the rig test is considered a diurnal test with respect to the provisions to account for 

ethanol emissions as described in paragraph (a)(1)(iv) of this section.

(4) If you fall short of the phase-in percentage specifications in paragraph (a)(5) of this 

section, you may designate the requisite number of Tier 2 vehicles as Tier 3 vehicles for 

purposes of demonstrating compliance with the Tier 3 standards in this section. To do 

this, factor those Tier 2 vehicles into the Tier 3 fleet-average emission calculation using 

an FEL that is equal to the applicable diurnal plus hot soak standard from the two-day test 

sequence. The Tier 3 emission standards do not apply to these Tier 2 vehicles. In 

addition, you may disregard the phase-in percentages specified in paragraph (a)(5) of this 

section if you instead comply based on one of the following alternative measures: 

(i) You may comply with an alternate phase-in schedule described in this paragraph 

(g)(4)(i). To do this, you must give us a detailed plan for describing how you will meet 

the alternate phase-in schedule. You comply with the alternate phase-in schedule by

calculating an evaporative phase-in index using the following equation that is at or above 
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1,280 for model years 2017 through 2022 (or 1,040 for model years 2018 through 2022 if 

you use the provisions of paragraph (g)(2)(i) of this section):

Evaporative phase-in index = 6∙APP2017 + 5∙APP2018 + 4∙APP2019 + 3∙APP2020 + 2∙APP2021

+ APP2022

Where:

APP = The phase-in percentage of vehicles meeting the Tier 3 evaporative emission 

standards for the indicated model year, based on actual sales, as described in paragraph 

(a)(5) of this section.

(ii) You may comply with an alternate phase-in schedule described in this paragraph 

(g)(4)(ii). To do this, you must give us a detailed plan for describing how you will meet 

the alternate phase-in schedule. You comply with the alternate phase-in schedule by

calculating an evaporative phase-in index using the following equation that is at or above 

420 for model years 2017 through 2022 (or 380 for model years 2018 through 2022 if 

you use the provisions of paragraph (g)(2)(i) of this section):

Evaporative phase-in index = APP2017 + APP2018 + APP2019 + APP2020 + APP2021 + 

APP2022

Where:

APP = The phase-in percentage of vehicles meeting the Tier 3 evaporative emission 

standards for the indicated model year, based on actual sales, as described in paragraph 

(a)(5) of this section.

(5) This paragraph (g)(5) describes an alternative approach to phasing in the evaporative 

and refueling emission standards for gaseous-fueled vehicles above 8,500 pounds 

GVWR. Under this alternative phase-in, you may disregard the requirements of this 

section related to evaporative emission standards that apply for these vehicles before 

model year 2019. Similarly, you may disregard the refueling emission standards of this 

section before model year 2019 for vehicles above 10,000 pounds GVWR. For model 

year 2019, you may exclude from the phase-in calculation any evaporative families with 

vehicles that have a Job 1 date on or before [INSERT DATE FOUR YEARS AFTER 

FRM SIGNATURE] (see 40 CFR 85.2304). Any vehicles not subject to Tier 3 

evaporative emission standards during this phase-in period must continue to comply with 

the evaporative emission standards in § 86.1816-08(d); such vehicles are subject to the 

useful life provisions in § 86.1805-12 relative to evaporative emission standards. Each 

vehicle counting toward the phase-in percentage under this paragraph (g)(5) must meet 

all the standards that apply throughout the useful life as specified in § 86.1805-17.

(h) Small-volume manufacturers. Small-volume manufacturers meeting the eligibility

requirements in § 86.1838 may delay complying with the requirements in this section 

until model year 2022. If meeting the Tier 3 standards would cause severe economic 

hardship, such manufacturers may ask us to approve an extended compliance deadline 

under the provisions of 40 CFR 1068.250, except that the solvency criterion does not 

apply and there is no maximum duration of the hardship relief. 

§§ 86.1814-01, 86.1814-02, 86.1815-01, and 86.1815-02 [Removed]

181. Remove §§ 86.1814-01, 86.1814-02, 86.1815-01, and 86.1815-02.
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182. A new § 86.1816-18 is added to subpart S to read as follows:

§ 86.1816-18 Emission standards for heavy-duty vehicles.

(a) Applicability and general provisions. This section describes exhaust emission 

standards that apply for model year 2018 and later complete heavy-duty vehicles. These 

standards are optional for incomplete heavy-duty vehicles and for heavy duty vehicles 

above 14,000 pounds GVWR as described in § 86.1801. Greenhouse gas emission 

standards are specified in § 86.1818 for MDPVs and in 40 CFR 1037.104 for other HDV. 

See § 86.1813 for evaporative and refueling emission standards. This section may apply

to vehicles before model year 2018 as specified in paragraph (b)(11) of this section. 

Separate requirements apply for MDPVs as specified in § 86.1811. See subpart A of this 

part for requirements that apply for incomplete heavy-duty vehicles and for heavy-duty 

engines certified independent of the chassis. The following general provisions apply:

(1) Test all vehicles as described in this section using a chassis dynamometer; establish 

appropriate load settings based on adjusted loaded vehicle weight (see § 86.1803).

(2) Some provisions apply differently depending on the vehicle’s power-to-weight ratio. 

Determine a vehicle’s power-to-weight ratio by dividing the engine’s rated power by the 

vehicle’s GVWR (in hp/pound). For purposes of this section, if a test group includes 

multiple configurations, use the vehicle with the highest power-to-weight ratio to 

characterize the test group.

(3) Use E10 test fuel as required in § 86.113, except as specified in this section.

(4) Measure emissions from hybrid electric vehicles (including plug-in hybrid electric 

vehicles) as described in 40 CFR part 1066, subpart F, except that these procedures do 

not apply for plug-in hybrid electric vehicles during charge-depleting operation.

(b) Tier 3 exhaust emission standards. Exhaust emissions may not exceed the Tier 3 

exhaust emission standards, as follows:

(1) Measure emissions using the procedures of subpart B of this part, using specific 

driving schedules and additional procedures as follows:

(i) The Federal Test Procedure (FTP) is based on testing with the Urban Dynamometer 

Driving Schedule (UDDS) specified in paragraph (a) of Appendix I of this part. 

(ii) The Heavy-Duty Supplemental Federal Test Procedure (HD-SFTP) involves testing 

with the UDDS, the SC03 driving schedule specified in paragraph (h) of Appendix I of 

this part, and one of the following additional driving schedules:

(A) For Class 2b vehicles, the US06 driving schedule specified in paragraph (g) of 

Appendix I of this part.

(B) For Class 2b vehicles with a power-to-weight ratio at or below 0.024 hp/pound that 

are certified to optional standards under paragraphs (b)(2) and (4) of this section, the 

highway portion of the US06 driving schedule characterized as the “second bag” in § 

86.159-08(a).

(C) For Class 3 vehicles, the LA-92 driving schedule as specified in paragraph (c) of 

Appendix I of this part. 

(iii) HD-SFTP emissions are calculated as a composite of test results over these driving 

schedules based on the following calculation:

HD-SFTP (g/mi) = 0.35∙FTP + 0.28∙HDSIM + 0.37∙SC03
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Where: 

HDSIM = the appropriate driving schedule specified in paragraph (b)(1)(ii)(A) through 

(C) of this section.

(iv) You may alternatively use FTP emission results to substitute for the SC03 value in 

the calculation under paragraph (b)(1)(iii) of this section for a given vehicle for any 

testing under this section. Such vehicles remain subject to the SFTP standard when 

tested over the SC03 driving schedule.

(v) Hydrocarbon emission standards are expressed as NMOG; however, you may

measure exhaust emissions based on nonmethane hydrocarbon instead of NMOG as 

described in 40 CFR 1066.635.

(2) Table 1 of this section describes fully phased-in Tier 3 standards that apply as 

specified in this paragraph (b) for the identified driving schedules. The FTP standards for 

NMOG+NOx apply on a fleet-average basis using discrete bin standards as described in 

paragraph (b)(4) of this section. The bin standards include additional emission standards 

for CO emissions, and for NMOG+NOx standards when testing over the HD-SFTP 

driving schedule. Table 1 follows:

Table 1 of § 86.1816-18

Fully Phased-in Tier 3 HDV Exhaust Emission Standards (g/mile)

HDV Class

Fleet-average

NMOG+NOx PM Formaldehyde

FTP FTP HD-SFTP FTP

2b 0.178 0.008 0.01010.006

3 0.247 0.010 0.007 0.006

1

For vehicles with a power-to-weight ratio at or below 0.024 hp/pound that are 

certified using the driving schedule described in paragraph (b)(1)(ii)(B) of this 

section, the HD-SFTP standard for PM is 0.007 g/mile instead of the value 

specified in the table.

(3) The FTP standards specified in this section apply equally for testing at low-altitude 

conditions and high-altitude conditions. The HD-SFTP standards described in this 

section apply only for testing at low-altitude conditions. 

(4) The FTP emission standard for NMOG+NOx is based on a fleet average in a given 

model year. You must specify a family emission limit (FEL) for each test group. The 

FEL serves as the emission standard for the test group with respect to all required FTP 

testing. Calculate your fleet-average emission level as described in § 86.1860 to show 

that you meet the specified standard. For multi-fueled vehicles, calculate fleet-average 

emission levels based only on emission levels for testing with gasoline or diesel fuel. 

You may generate or use emission credits for banking and trading and you may use 

banked or traded credits for demonstrating compliance with the FTP emission standard 

for NMOG+NOx as described in § 86.1861. You comply with the emission standard for 

a given model year if you have enough credits to show that your fleet-average emission 

level is at or below the applicable standard. You may exchange credits between or 

among any test groups subject to standards under this section. Specify one of the 
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identified values from Table 2 or Table 3 of this section as the FEL for demonstrating 

that your fleet-average emission level complies with the FTP emission standard for 

NMOG+NOx. These FEL values define emission bins that also determine corresponding 

emission standards for NMOG+NOx emissions over the HD-SFTP driving schedule and 

for CO emissions, as follows:

Table 2 of § 86.1816-18

Tier 3 Bin Standards—Class 2b (g/mile)

FEL 

Name

NMOG+NOx CO

FTP (FEL) HD-SFTP1FTP HD-SFTP

Bin 250 0.250 0.800 6.4 22.0

Bin 200 0.200 0.800 4.2 22.0

Bin 170 0.170 0.450 4.2 12.0

Bin 150 0.150 0.450 3.2 12.0

Bin 020.000 0.000 0.0 0.0

1 Vehicles with a power-to-weight ratio at or below 0.024 

hp/pound that are certified using the driving schedule 

described in paragraph (b)(1)(ii)(B) of this section, the 

following HD-SFTP bin standards for NMOG+NOx apply 

instead of those identified in the table: 0.350 g/mile for Bin 

150 and Bin 170; and 0.550 g/mile for Bin 200 and Bin 250.

2 Vehicles certified to Bin 0 must also meet PM and 

formaldehyde standards of 0.000 g/mile instead of the 

standards specified in paragraph (b)(2) of this section.

Table 3 of § 86.1816-18

Tier 3 Bin Standards—Class 3 (g/mile)

FEL 

Name

NMOG+NOx CO

FTP (FEL) HDSFTP FTP HD-SFTP

Bin 400 0.400 0.550 7.3 6.0

Bin 270 0.270 0.550 4.2 6.0

Bin 230 0.230 0.350 4.2 4.0

Bin 200 0.200 0.350 3.7 4.0

Bin 010.000 0.000 0.0 0.0

1 Vehicles certified to Bin 0 must also meet PM and 

formaldehyde standards of 0.000 g/mile instead of the 

standards specified in paragraph (b)(2) of this section.

(5) [Reserved]

(6) The full Tier 3 program includes new emission standards for NMOG+NOx, PM, CO, 

and formaldehyde; it also includes measurement with a new test fuel and a longer useful 

life. Vehicles meeting all these requirements are considered Final Tier 3 vehicles. 

Vehicles that do not meet all the Tier 3 requirements are considered Interim Tier 3 

vehicles. The Tier 3 PM standards phase in over several years. Any vehicles not subject 

to Tier 3 PM standards during the phase-in period must continue to comply with the PM 

standards in § 86.1816-08. Paragraph (b)(7) of this section describes how to transition to 
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Tier 3 standards for emissions other than PM. The following provisions describe the 

primary approach for phasing in the Tier 3 PM standards:

(i) You must meet the FTP emission standard for PM with 20, 40, 70, and 100 percent of 

your projected nationwide sales of all vehicles subject to this section in model years 2018 

through 2021, respectively. Each vehicle meeting the Tier 3 FTP standard for PM must 

also meet the Tier 3 HD-SFTP standard for PM.

(ii) You may disregard the phase-in percentages specified in paragraph (b)(6)(i) of this 

section if you instead comply with an indexed PM phase-in schedule as described in this 

paragraph (b)(6)(ii). To do this, you must notify us of your intent before January 1, 2018, 

and include a detailed plan for complying with the indexed phase-in schedule. You 

comply with the indexed phase-in schedule by calculating a PM phase-in index at or 

above 440 using the following equation for model years 2018 through 2021:

PM phase-in index = 4∙APP2018 + 3∙APP2019 + 2∙APP2020 + APP2021

Where:

APP = The phase-in percentage of vehicles meeting the Tier 3 PM standards for the 

indicated model year, based on actual sales.

(iii) Vehicles meeting the Tier 3 PM standards must meet those standards over the useful 

life as specified in § 86.1805. Note that Interim Tier 3 vehicles may have different useful 

life values for PM emission standards than for other emission standards.

(iv) Measure PM emissions from all vehicles using the same test fuel used for measuring 

NMOG+NOx emissions.

(v) You may certify Interim Tier 3 vehicles based on carryover data.

(vi) You may use the alternative phase-in provisions described in paragraph (b)(8) of this 

section to transition to the Tier 3 exhaust emission standards on a different schedule. 

(7) The following provisions describe the primary approach for phasing in the Tier 3 

standards other than PM in 2022 and earlier model years:

(i) The fleet-average FTP emission standard for NMOG+NOx phases in over several 

years as described in this paragraph (b)(7)(i). You must identify FELs as described in 

paragraph (b)(4) of this section and calculate a fleet-average emission level to show that 

you meet the FTP emission standard for NMOG+NOx that applies for each model year. 

You may certify using transitional bin standards specified in Table 5 of this section 

through model year 2021; these vehicles are subject to FTP emission standards for PM 

and formaldehyde as described in paragraph (b)(2) of this section. You may use the E0 

test fuel specified in § 86.113 for gasoline-fueled vehicles certified to the transitional 

bins; the useful life period for these vehicles is 120,000 miles or 11 years. Fleet-average 

FTP emission standards decrease as shown in the following table:
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Table 4 of § 86.1816-18

Declining Fleet-Average FTP 

Emission Standards for NMOG+NOx (g/mile)

Model

Year Class 2b Class 3

201610.333 0.548

201710.310 0.508

2018 0.278 0.451

2019 0.253 0.400

2020 0.228 0.349

2021 0.203 0.298

2022 0.178 0.247

1

Fleet-average standards are shown for 2016 and 

2017 for purposes of voluntary early compliance 

as described in paragraph (b)(11) of this section.

Table 5 of § 86.1816-18

Transitional Tier 3 FTP Bin Standards (g/mile)1

Class FEL Name NMOG+NO

x

NOx2 CO

2b Bin 395 0.395 0.2 6.4

Bin 340 0.340 0.2 6.4

3

Bin 630 0.630 0.4 7.3

Bin 570 0.570 0.4 7.3

1 Vehicles certified to Transitional Tier 3 FTP bins are not subject to HDSFTP standards.

2 The NOx standard applies only for certification testing with emission-data 

vehicles.

(ii) You may use the alternative phase-in provisions described in paragraph (b)(8) of this 

section to transition to the Tier 3 exhaust emission standards on a different schedule. 

(8) This paragraph (b)(8) describes an alternative approach to phasing in the Tier 3 

emission standards. If you choose this approach, you must phase in the Tier 3 standards 

for all your vehicles subject to this section according to this schedule. Under this 

alternative phase in, you must meet all the standards specified in paragraph (b)(2) of this 

section according to the phase-in schedule specified in Table 6 of this section based on 

the indicated percentage of your projected nationwide sales in each model year. These 

vehicles must meet the applicable FTP emission standard for CO and the HD-SFTP 

emission standards for NMOG+NOx and CO that apply for Class 2b Bin 170 and Class 3 

Bin 230 as described in paragraph (b)(4) of this section. Any vehicles not subject to Tier 

3 standards during the phase-in period must continue to comply with the gaseous exhaust 

emission standards in § 86.1816-08. Each vehicle counting toward the PM phase-in 

percentage under this paragraph (b)(8) in model years 2019 and 2020 must also be 

included in the portion of the fleet meeting the Tier 3 standards for pollutants other than 

PM. Each vehicle counting toward the phase-in percentage for any pollutant must use the 

Tier 3 test fuel specified in § 86.113-07. The following exceptions and special provisions 

apply under this paragraph (b)(8): 
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(i) For model year 2019, you may exclude from the phase-in calculation any test groups 

that have a Job 1 date on or before [INSERT DATE FOUR YEARS AFTER FRM 

SIGNATURE] (see 40 CFR 85.2304).

(ii) You may generate Tier 3 emission credits during the phase-in period if all your preTier 3 vehicles in a given model year have FELs at or below the NOx and NMHC 

standards in § 86.1816-08. Determine emission credits by calculating fleet-average 

emission levels for Tier 3 and pre-Tier 3 vehicles together; for pre-Tier 3 vehicles use an 

NMOG+NOx equivalent FEL of 0.395 g/mile for Class 2b vehicles and 0.630 g/mile for 

Class 3 vehicles. 

Table 6 of § 86.1816-18

Alternative Phase-in Schedule 

Model

Year

Class 2b Class 3

PM Other 

than PM PM Other than PM

2019 40% 65% 40% 60%

2020 70% 77% 70% 73%

2021 100% 88% 100% 87%

2022 100% 100% 100% 100%

(9) You may not use credits generated from vehicles certified under § 86.1816-08 for 

demonstrating compliance with the Tier 3 standards.

(10) [Reserved] 

(11) You may voluntarily certify your vehicles under this section in model years 2016 

and 2017. If you do this, the fleet-average FTP emission standards for NMOG+NOx 

apply to all your heavy-duty vehicles under this section as specified in paragraph (b)(7)(i) 

of this section. Use any of the available bin standards as described in this section. 

Vehicles certified under this paragraph (b)(11) must comply with the PM standards 

specified in § 86.1816-08 instead of the Tier 3 PM standards specified in this section.

(12) Alternate standards apply for in-use testing with 2022 and earlier model year 

vehicles as described in this paragraph (b)(12). These alternate standards apply in the 

first model year that a test group is certified to Tier 3 FTP or HD-SFTP standards for 

NMOG+NOx or PM under this section. The alternate in-use standards also apply in the 

following model year (but not beyond 2022) for carryover test groups certified to the 

same bin standards. If you certify a test group to more stringent bin standards under this 

section in a given model year, the alternate in-use standards apply as if that were the first 

model year of certifying to the Tier 3 standards. The provisions of this section apply

separately for NMOG+NOx and PM. This paragraph (b)(12) does not apply for Bin 0 

vehicles.

(i) The alternate in-use FTP standards for PM are 0.016 g/mile for Class 2b vehicles and 

0.020 g/mile for Class 3 vehicles. 

(ii) The alternate in-use HD-SFTP standards for PM are 0.012 g/mile for Class 2b 

vehicles with a power-to-weight ratio at or below 0.024 hp/pound that are certified to 

optional standards under paragraphs (b)(2) and (4) of this section, and 0.015 g/mile for 

other Class 2b vehicles. The alternate in-use HD-SFTP standard for PM is 0.012 g/mile 
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for Class 3 vehicles. Alternate in-use HD-SFTP standards do not apply for vehicles 

certified to the transitional bins described in paragraph (b)(7) of this section.

(iii) Alternate in-use FTP and HD-SFTP standards for NMOG+NOx apply as specified in 

the following table: 

Table 7 of § 86.1816-18

Alternate In-use NMOG+NOx Standards (g/mile)

Class FEL Name FTP HD-SFTP1

2b

Bin 250 0.370 1.120

Bin 200 0.300 1.120

Bin 170 0.250 0.630

Bin 150 0.220 0.630

3

Bin 400 0.600 0.770

Bin 270 0.400 0.770

Bin 230 0.340 0.490

Bin 200 0.300 0.490

1

For Class 2b vehicles with a power-to-weight ratio at or below 0.024 

hp/pound that are certified to optional standards under paragraphs (b)(2) 

and (4) of this section, the following alternate in-use FTP standards for 

NMOG+NOx apply instead of those identified in the table: 0.490 g/mile 

for Bin 150 and Bin 170; and 0.770 g/mile for Bin 200 and Bin 250. Note 

that vehicles certified to transitional Tier 3 FTP bins are not subject to HDSFTP standards.

(13) Keep records as needed to show that you meet the requirements specified in this 

paragraph (b) for phasing in standards and for complying with declining fleet-average 

average standards.

(c) Highway NMOG+NOx exhaust emission standard. For vehicles certified to any of the 

Tier 3 standards specified in paragraph (b) of this section, NMOG+NOx emissions 

measured on the highway test cycle in 40 CFR part 600, subpart B, may not exceed the 

applicable NMOG+NOx bin standard for FTP testing. Demonstrate compliance with this 

standard for low-mileage vehicles by applying the appropriate deterioration factor. 

(d) Provisions for Otto-cycle engines. The special provisions described in § 86.1811-

17(d) apply to vehicles with Otto-cycle engines that are certified under this section.

(e) Small-volume manufacturers. Small-volume manufacturers meeting the eligibility

requirements in § 86.1838 may delay complying with the requirements in this section 

until model year 2022. This also applies for continuing to use the E0 test fuel specified in 

§ 86.113 through model year 2021. If meeting the Tier 3 standards would cause severe 

economic hardship, such manufacturers may ask us to approve an extended compliance 

deadline under the provisions of 40 CFR 1068.250, except that the solvency criterion 

does not apply and there is no maximum duration of the hardship relief. 

183. Section § 86.1817-08 is amended by revising the introductory text to read as 

follows:

§ 86.1817-08 Complete heavy-duty vehicle averaging, trading, and banking 

program.

Section 86.1817–08 includes text that specifies requirements that differ from § 86.1817–

05. Where a paragraph in § 86.1817–05 is identical and applicable to § 86.1817–08, this 
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may be indicated by specifying the corresponding paragraph and the statement 

“[Reserved]. For guidance see § 86.1817–05.” This section does not apply for NOx or 

NMOG+NOx emissions for vehicles certified to the Tier 3 standards in § 86.1816-18, 

including those vehicles that certify to the Tier 3 standards before model year 2018. See 

§§ 86.1860 and 86.1861 for provisions that apply for vehicles certified to the Tier3 

standards.

* * * * *

184. Section 86.1818-12 is amended by revising paragraph (a) to read as follows:

§ 86.1818-12 Greenhouse gas emission standards for light-duty vehicles, light-duty 

trucks, and medium-duty passenger vehicles.

(a) Applicability. (1) This section contains standards and other regulations applicable to 

the emission of the air pollutant defined as the aggregate group of six greenhouse gases: 

Carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons, and 

sulfur hexafluoride. This section applies to 2012 and later model year LDV, LDT and 

MDPV, including multi-fuel vehicles, vehicles fueled with alternative fuels, hybrid 

electric vehicles, plug-in hybrid electric vehicles, electric vehicles, and fuel cell vehicles. 

Unless otherwise specified, multi-fuel vehicles must comply with all requirements 

established for each consumed fuel. The provisions of this section, except paragraph (c), 

also apply to clean alternative fuel conversions as defined in 40 CFR 85.502, of all model 

year light-duty vehicles, light-duty trucks, and medium-duty passenger vehicles. 

Manufacturers that qualify as a small business according to the requirements of § 

86.1801–12(j) are exempt from the emission standards in this section. Manufacturers that 

have submitted a declaration for a model year according to the requirements of § 

86.1801–12(k) for which approval has been granted by the Administrator are 

conditionally exempt from the emission standards in paragraphs (c) through (e) of this 

section for the approved model year.

(2) The standards specified in this section apply only for testing at low-altitude 

conditions. However, manufacturers must submit an engineering evaluation indicating 

that common calibration approaches are utilized at high altitude. Any deviation from low 

altitude emission control practices must be included in the auxiliary emission control 

device (AECD) descriptions submitted at certification. Any AECD specific to high 

altitude requires engineering emission data for EPA evaluation to quantify any emission 

impact and determine the validity of the AECD.

* * * * *

185. Section § 86.1821-01 is amended by revising paragraphs (a) and (b) introductory 

text an adding paragraphs (b)(10) and (f) to read as follows:

§ 86.1821-01 Evaporative/refueling family determination.

(a) The gasoline-, ethanol-, methanol-, liquefied petroleum gas-, and natural gas-fueled 

vehicles described in a certification application will be divided into groupings expected to 

have similar evaporative and/or refueling emission characteristics (as applicable) 

throughout their useful life. Each group of vehicles with similar evaporative and/or 

refueling emission characteristics shall be defined as a separate evaporative/refueling 
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family. Manufacturers shall use good engineering judgment to determine 

evaporative/refueling families.

(b) For vehicles that operate on volatile liquid fuels to be classed in the same 

evaporative/refueling family, they must be similar with respect to all the following items:

* * * * *

(10) Evaporative emission standard or family emission limit (FEL).

* * * * *

(f) For vehicles to be classed in the same leak family, they must be similar with respect to 

the items listed in paragraph (b) of this section and use the same OBD method for 

detecting leaks.

186. Section § 86.1823-08 is amended as follows:

a. By revising the introductory text.

b. By removing and reserving paragraph (g).

c. By adding paragraph (n).

§ 86.1823-08 Durability demonstration procedures for exhaust emissions.

This section describes durability demonstration procedures for exhaust emissions. 

Eligible small-volume manufacturers or small-volume test groups may optionally meet 

the requirements of §§ 86.1826 and 86.1838 instead of the requirements of paragraphs 

(a) through (m) of this section. A separate durability demonstration is required for each 

durability group.

* * * * *

(n) Emission component durability. [Reserved]. For guidance see 40 CFR 86.1823-01(e). 

187. Section § 86.1824-08 is amended as follows:

a. By revising the introductory text.

b. By revising paragraphs (a) and (f)(1).

c. By removing and reserving paragraph (h).

d. By adding paragraph (k).

§ 86.1824-08 Durability demonstration procedures for evaporative emissions.

This section describes durability demonstration procedures for evaporative emissions. 

Eligible small-volume manufacturers or small-volume test groups may optionally meet 

the requirements of §§ 86.1826 and 86.1838 instead of the requirements of paragraphs (a) 

through (j) of this section. A separate durability demonstration is required for each 

evaporative/refueling family. 

(a) Durability program objective. The durability program must predict an expected in-use 

emission deterioration rate and emission level that effectively represents a significant 

majority of the distribution of emission levels and deterioration in actual use over the full 

useful life of candidate in-use vehicles of each vehicle design which uses the durability

program. This requirement applies for all SHED-based measurements except the bleed 

emission test. The standard for bleed emissions applies for the full useful life, but 

manufacturers do not need to establish deterioration factors for bleed emissions. The 

requirements of this section do not apply for spitback or leak standards. 

* * * * *
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(f) * * *

(1) For gasoline fueled vehicles certified to meet the evaporative emission standards set 

forth in this subpart, any mileage accumulation method for evaporative emissions must 

employ gasoline fuel for the entire mileage accumulation period which contains ethanol 

in, at least, the highest concentration permissible in gasoline under federal law and that is 

commercially available in any state in the United States. Unless otherwise approved by 

the Administrator, the manufacturer must determine the appropriate ethanol concentration 

by selecting the highest legal concentration commercially available during the calendar 

year before the one in which the manufacturer begins its mileage accumulation. The 

manufacturer must also provide information acceptable to the Administrator to indicate 

that the mileage accumulation method is of sufficient design, duration and severity to 

stabilize the permeability of all non-metallic fuel and evaporative system components to 

the mileage accumulation fuel constituents.

* * * * *

(k) Emission component durability. [Reserved]. For guidance see 40 CFR 86.1824-01(d).

188. Section § 86.1826-01 is revised to read as follows:

§ 86.1826-01 Assigned deterioration factors for small-volume manufacturers and 

small-volume test groups.

(a) Applicability. This program is an option available for small-volume manufacturers 

and small-volume test groups as described in § 86.1838. 

(b) Determination of deterioration factors. No service accumulation method or 

vehicle/component selection method is required. Deterioration factors for all types of 

regulated emissions are assigned using the provisions in this paragraph (b). A separate 

assigned deterioration factor is required for each durability group. Manufacturers shall 

use good engineering judgment in applying deterioration factors. Manufacturers may use 

assigned deterioration factors that the Administrator determines and prescribes.

(1) The deterioration factors will be the Administrator's estimate, periodically updated 

and published in a guidance document, of the 70th percentile deterioration factors 

calculated using the industry-wide database of previously completed durability data 

vehicles or engines used for certification.

(2) The Administrator may use discretion to develop assigned deterioration factors using 

alternative methods if there is insufficient information to calculate an appropriate 

industry-wide deterioration factor (for example: a new engine technology coupled with a 

proven emission control system). These methods may include the use of assigned 

deterioration factors based on similar durability vehicles.

(3) Alternatively, with advance approval from the Administrator, a manufacturer may use 

deterioration factors developed by another manufacturer. The manufacturer seeking to 

use these deterioration factors must—

(i) Demonstrate that the engines from the two manufacturers share technical parameters 

to the degree that would support the conclusion that a common deterioration factor 

should apply for both vehicle configurations as defined in § 86.1803. 
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(ii) Provide supporting information, such as histograms of exhaust temperature data, 

comparisons of vehicle weight and road load horsepower, or comparisons of powertrains 

and emission control systems.

189. Section 86.1828-01 is amended by removing and reserving paragraph (d) and 

adding paragraph (g) to read as follows: 

§ 86.1828-01 Emission data vehicle selection.

* * * * *

(g) Cold temperature NMHC testing. For cold temperature NMHC exhaust emission 

compliance for each durability group, the manufacturer must select the vehicle expected 

to emit the highest NMHC emissions at 20 °F on candidate in-use vehicles from the test 

vehicles specified in paragraph (a) of this section. When the expected worst-case cold 

temperature NMHC vehicle is also the expected worst-case cold temperature CO vehicle 

as selected in paragraph (c) of this section, then cold temperature testing is required only 

for that vehicle; otherwise, testing is required for both the worst-case cold temperature 

CO vehicle and the worst-case cold temperature NMHC vehicle.

§ 86.1828-10 [Removed]

190. Remove § 86.1828-10.

191. Section 86.1829-01 is amended as follows:

a. By removing and reserving paragraph (b)(1)(iii)(C).

b. By revising paragraph (b)(2)(i).

c. By adding paragraph (b)(2)(iv).

d. By revising paragraph (b)(4).

f. By removing and reserving paragraph (d).

§ 86.1829-01 Durability and emission testing requirements; waivers. 

* * * * *

(b) * * *

(2) * * *

(i) Testing at low altitude. One EDV in each evaporative/refueling family and 

evaporative/refueling emission control system combination must be tested in accordance 

with the evaporative/refueling test procedure requirement of subpart B of this part. The 

configuration of the EDV will be determined under the provisions of § 86.1828–01. The 

EDV must also be tested for exhaust emission compliance using the FTP and SFTP 

procedures of subpart B of this part. In lieu of testing natural gas or hydrogen fueled 

vehicles to demonstrate compliance with the evaporative and refueling emission 

standards specified in this subpart, a manufacturer may provide a statement in its 

application for certification that, based on the manufacturer's engineering evaluation of 

appropriate testing and/or design parameters, all light-duty vehicles, light-duty trucks, 

and complete heavy-duty vehicles comply with applicable emission standards. This same 

testing exemption applies for vehicles fueled by liquefied petroleum gas, except that 

refueling tests are required for systems that allow venting during the refueling operation.

* * * * *
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(iv) For diesel-fueled light-duty vehicles, a manufacturer may provide a statement in the 

application for certification that vehicles comply with the refueling emission standard 

instead of submitting test data. Such a statement must be based on previous emission 

tests, development tests, or other appropriate information, and good engineering 

judgment.

* * * * *

(4) Electric vehicles and fuel cell vehicles. For electric vehicles and fuel cell vehicles, 

manufacturers may provide a statement in the application for certification that vehicles 

comply with all the requirements of this subpart instead of submitting test data. Such a 

statement must be based on previous emission tests, development tests, or other 

appropriate information, and good engineering judgment.

* * * * *

192. A new § 86.1829-15 is added to subpart S to read as follows:

§ 86.1829-15 Durability and emission testing requirements; waivers.

This section describes general testing requirements for certifying vehicles under this 

subpart, and includes several provisions allowing for statements of compliance instead of 

testing in certain circumstances. Where a manufacturer provides a statement instead of 

test data under this section, it must be based on previous emission tests, development 

tests, or other appropriate information, and on good engineering judgment.

(a) One durability demonstration is required for each durability group. The configuration 

of the DDV is determined according to § 86.1822. The DDV shall be tested and 

accumulate service mileage according to the provisions of §§ 86.1823, 86.1824, 86.1825, 

and 86.1831. Small-volume manufacturers and small-volume test groups may optionally 

use the alternative durability provisions of § 86.1838.

(b) The manufacturer must test EDVs as follows to demonstrate compliance with 

emission standards:

(1) Test one EDV in each durability group using the test procedures in 40 CFR part 1066 

to demonstrate compliance with cold temperature CO and NMHC exhaust emission 

standards. 

(2) Test one EDV in each test group using the FTP and SFTP test procedures in 40 CFR 

part 1066 and the HFET test procedures of 40 CFR part 600, subpart B, to demonstrate 

compliance with other exhaust emission standards. 

(3) Test one EDV in each evaporative/refueling family and evaporative/refueling 

emission control system combination using the test procedures in subpart B of this part to 

demonstrate compliance with evaporative and refueling emission standards.

(c) The manufacturer must demonstrate compliance with emission standards at lowaltitude conditions as described in paragraph (b) of this section. For standards that apply 

at high-altitude conditions, the manufacturer may either perform the same tests or provide 

a statement in the application for certification that, based on an engineering evaluation of 

appropriate testing to measure or simulate high-altitude emissions, all vehicles comply

with applicable emission standards at high altitude.

(d) Manufacturers may omit exhaust testing for certification in certain circumstances as 

follows: 
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(1) For vehicles subject to the Tier 3 PM standards in §§ 86.1811, a manufacturer may

provide a statement in the application for certification that vehicles comply with 

applicable PM standards instead of submitting PM test data for a certain number of 

vehicles. However, each manufacturer must test vehicles from a minimum number of 

durability data groups as follows:

(i) Manufacturers with a single durability data group subject to the Tier 3 PM standards 

in § 86.1811 must submit PM test data for that group. 

(ii) Manufacturers with two to eight durability data groups subject to the Tier 3 PM 

standards in § 86.1811 must submit PM test data for at least two durability data groups 

each model year. EPA will work with the manufacturer to select durability data groups 

for testing, with the general expectation that testing will rotate to cover a manufacturer’s 

whole product line over time. If a durability data group has been certified in an earlier 

model year based on submitted PM data, and that durability data group is eligible for 

certification using carryover test data, that carryover data may count toward meeting the 

requirements of this paragraph (d)(1), subject to the selection of durability data groups. 

(iii) Manufacturers with nine or more durability data groups subject to the Tier 3 PM 

standards in § 86.1811 must submit PM test data for at least 25 percent of those durability

data groups each model year. We will work with the manufacturer to select durability

data groups for testing as described in paragraph (d)(1)(ii) of this section.

(2) Small-volume manufacturers may provide a statement in the application for 

certification that vehicles comply with the applicable PM standard instead of submitting 

test data.

(3) Manufacturers may omit PM measurements for fuel economy and GHG testing 

conducted in addition to the testing needed to demonstrate compliance with the PM 

emission standards.

(4) Manufacturers may provide a statement in the application for certification that 

vehicles comply with the applicable formaldehyde standard instead of submitting test 

data.

(5) When conducting Selective Enforcement Audit testing, a manufacturer may petition 

the Administrator to waive the requirement to measure PM emissions and formaldehyde 

emissions.

(e) Manufacturers may omit evaporative or refueling testing for certification in certain 

circumstances as follows: 

(1) For diesel-fueled vehicles, a manufacturer may provide a statement in the application 

for certification that vehicles comply with the refueling emission standard instead of 

submitting test data.

(2) For vehicles fueled by natural gas, a manufacturer may provide a statement in the 

application for certification that vehicles comply with evaporative emission standards 

instead of submitting test data. Compressed natural gas vehicles meeting the 

requirements for fueling connection devices in § 86.1813-17(f)(1) are deemed to comply

with evaporative and refueling emission standards.

(3) For vehicles fueled by liquefied petroleum gas, a manufacturer may provide a 

statement in the application for certification that vehicles comply with evaporative and 
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refueling emission standards instead of submitting test data, except that refueling tests are 

required for systems that allow venting during the refueling operation.

(4) Manufacturers may provide a statement in the application for certification that 

vehicles comply with the leak standard in § 86.1813 instead of submitting test data.

(5) For vehicles certified to the refueling emission standards in §§ 86.1811 or 86.1813, a 

manufacturer may provide a statement in the application for certification that vehicles 

comply with the fuel dispensing spitback standard instead of submitting test data.

(6) In lieu of testing vehicles for the supplemental two-diurnal test sequence, a 

manufacturer may optionally provide a statement of compliance in its application for 

certification that, based on the manufacturer's good engineering judgment, all vehicles in 

the evaporative/refueling emission family comply with the evaporative emission standard 

for the supplemental two-diurnal test sequence.

(i) The option to provide a statement of compliance in lieu of 2-diurnal evaporative 

certification test data is limited to vehicles with conventional evaporative emission 

control systems (as determined by the Administrator). EPA may perform confirmatory 2-

diurnal evaporative emission testing on test vehicles certified using this option. If data 

shows noncompliance, it will be addressed through § 86.1851. Also, if data shows 

noncompliance, EPA will generally disallow subsequent waivers for the applicable 

evaporative family.

(ii) Manufacturers shall supply information if requested by EPA in support of the 

statement of compliance described in this paragraph (e)(6). This information shall include 

evaporative calibration information for the emission-data vehicle and for other vehicles in 

the evaporative/refueling family, including, but not limited to, canister type, canister 

volume, canister working capacity, canister shape and internal configuration, fuel tank 

volume, fuel tank geometry, the type of fuel delivery system (return, returnless, variable 

flow fuel pump, etc.), a description of the input parameters and software strategy used to 

control the evaporative canister purge, the nominal purge flow volume (in bed volumes) 

when vehicles are driven over the 2-diurnal (FTP) driving cycle, the nominal purge flow 

volume (in bed volumes) when vehicles are driven over the 3-diurnal (FTP + running 

loss) driving cycle, and other supporting information as necessary to demonstrate that the 

purge flow rate calibration on the 2-diurnal test sequence is adequate to comply with the 

evaporative emission standard for the supplemental two-diurnal test sequence.

(7) Where a California evaporative emission standard is at least as stringent as a 

comparable federal evaporative emission standard for a vehicle, we may accept test data 

demonstrating compliance with the California standard as demonstrating compliance with 

the comparable standard under this subpart. We may require you to provide test data 

clearly demonstrating that a vehicle tested using the California-specified test procedures 

will meet the comparable standard under this subpart when tested using the test 

procedures specified in this part.

(8) Through model year 2019, we may accept test data demonstrating compliance with 

the California refueling emission standard as demonstrating compliance with the 

analogous refueling emission standard under this subpart if all the following conditions 

apply:
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(i) You certified the vehicles in model year 2016 to California’s refueling emission 

standards.

(ii) You are certifying the vehicles to refueling standards for the new model year based 

on carryover data instead of performing new testing.

(iii) You are also certifying the vehicles for evaporative emissions based on California 

test procedures under the provisions of paragraph (e)(6) of this section. 

(9) For vehicles with fuel tanks exceeding 35 gallons nominal fuel tank capacity, and for 

any incomplete vehicles, a manufacturer may provide a statement in the application for 

certification that vehicles comply with refueling emission standards instead of submitting 

test data, consistent with 40 CFR 1037.103(c).

(f) For electric vehicles and fuel cell vehicles, manufacturers may provide a statement in 

the application for certification that vehicles comply with all the requirements of this 

subpart instead of submitting test data. Tailpipe emissions of regulated pollutants from 

vehicles powered solely by electricity are deemed to be zero.

193. Section 86.1837-01 is amended by revising paragraph (a) to read as follows:

§ 86.1837-01 Rounding of emission measurements.

(a) Unless otherwise specified, the results of all emission tests shall be rounded to the 

number of places to the right of the decimal point indicated by expressing the applicable 

emission standard of this subpart to one additional significant figure, in accordance with 

40 CFR 1065.20. 

* * * * *

194. Section 86.1838-01 is amended by revising paragraphs (a), (b), (c), and (d) 

introductory text to read as follows:

§ 86.1838-01 Small-volume manufacturer certification procedures.

(a) Overview. The small-volume manufacturer certification procedures described in 

paragraphs (b) and (c) of this section are optional. Small-volume manufacturers may use 

these optional procedures to demonstrate compliance with the general standards and 

specific emission requirements contained in this subpart.

(b) Eligibility requirements —(1) Small-volume manufacturers. (i) Optional smallvolume manufacturer certification procedures apply for vehicles produced by 

manufacturers with the following number of combined sales of vehicles subject to 

standards under this subpart in all states and territories of the United States in the model 

year for which certification is sought, including all vehicles and engines imported under 

the provisions of 40 CFR 85.1505 and 85.1509:

(A) 5,000 units for the Tier 3 standards described in §§ 86.1811, 86.1813, and 86.1816. 

This volume threshold applies for phasing in the Tier 3 standards and for determining the 

corresponding deterioration factors. This is based on average nationwide sales volumes 

for model years 2012 through 2014 for manufacturers that sell vehicles in model year 

2012. The provision allowing delayed compliance with the Tier 3 standards applies for 

qualifying companies even if sales after model year 2014 increase beyond 5,000 units. 

Manufacturers with no sales in model year 2012 may instead rely on projected sales 

volumes; however, if nationwide sales exceed an average value of 5,000 units in any
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three consecutive model years, the manufacturer is no longer eligible for provisions that 

apply to small-volume manufacturers after two additional model years. For example, if 

actual sales in model years 2015 through 2017 exceed 5,000 units, the small-volume 

provisions would no longer apply starting in model year 2020.

(B) 15,000 units for all other requirements. See § 86.1845 for separate provisions that 

apply for in-use testing.

(ii) If a manufacturer’s aggregated sales in the United States, as determined in paragraph 

(b)(3) of this section are fewer than the number of units specified in paragraph (b)(1)(i) of 

this section, the manufacturer (or each manufacturer in the case of manufacturers in an 

aggregated relationship) may certify under the provisions of paragraph (c) of this section.

(iii) A manufacturer that qualifies as a small business under the Small Business 

Administration regulations in 13 CFR part 121 is eligible for all the provisions that apply

for small-volume manufacturers under this subpart. See § 86.1801-12(j) to determine 

whether companies qualify as small businesses.

(iv) The sales volumes specified in this section are based on actual sales, unless otherwise 

specified. 

(v) Except for delayed implementation of new emission standards, an eligible 

manufacturer must transition out of the special provisions that apply for small-volume 

manufacturers as described in § 86.1801-12(k)(2)(i) through (iii) if sales volumes 

increase above the applicable threshold. 

(2) Small-volume test groups. (i) If the aggregated sales in all states and territories of the 

United States, as determined in paragraph (b)(3) of this section are equal to or greater 

than 15,000 units, then the manufacturer (or each manufacturer in the case of 

manufacturers in an aggregated relationship) will be allowed to certify a number of units 

under the small-volume test group certification procedures in accordance with the criteria 

identified in paragraphs (b)(2)(ii) through (iv) of this section.

(ii) If there are no additional manufacturers in an aggregated relationship meeting the 

provisions of paragraph (b)(3) of this section, then the manufacturer may certify whole 

test groups whose total aggregated sales (including heavy-duty engines) are less than 

15,000 units using the small-volume provisions of paragraph (c) of this section.

(iii) If there is an aggregated relationship with another manufacturer which satisfies the 

provisions of paragraph (b)(3) of this section, then the following provisions shall apply:

(A) If none of the manufacturers own 50 percent or more of another manufacturer in the 

aggregated relationship, then each manufacturer may certify whole test groups whose 

total aggregated sales (including heavy-duty engines) are less than 15,000 units using the 

small-volume provisions of paragraph (c) of this section.

(B) If any of the manufacturers own 50 percent or more of another manufacturer in the 

aggregated relationship, then the limit of 14,999 units must be shared among the 

manufacturers in such a relationship. In total for all the manufacturers involved in such a 

relationship, aggregated sales (including heavy-duty engines) of up to 14,999 units may

be certified using the small-volume provisions of paragraph (c) of this section. Only

whole test groups shall be eligible for small-volume status under paragraph (c) of this 

section.
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(iv) In the case of a joint venture arrangement (50/50 ownership) between two 

manufacturers, each manufacturer retains its eligibility for 14,999 units under the smallvolume test group certification procedures, but the joint venture must draw its maximum 

14,999 units from the units allocated to its parent manufacturers. Only whole test groups 

shall be eligible for small-volume status under paragraph (c) of this section.

(3) Sales aggregation for related manufacturers. The projected or actual sales from 

different firms shall be aggregated in the following situations:

(i) Vehicles and/or engines produced by two or more firms, one of which is 10 percent or 

greater part owned by another;

(ii) Vehicles and/or engines produced by any two or more firms if a third party has equity 

ownership of 10 percent or more in each of the firms;

(iii) Vehicles and/or engines produced by two or more firms having a common corporate 

officer(s) who is (are) responsible for the overall direction of the companies;

(iv) Vehicles and/or engines imported or distributed by all firms where the vehicles 

and/or engines are manufactured by the same entity and the importer or distributor is an 

authorized agent of the entity.

(c) Small-volume provisions. Small-volume manufacturers and small-volume test groups 

shall demonstrate compliance with all applicable sections of this subpart, with the 

following exceptions: 

(1) Durability demonstration. Use the provisions of § 86.1826 rather than the 

requirements of §§ 86.1823, 86.1824, and 86.1825.

(2) In-use verification testing. Measure emissions from in-use vehicles as described in § 

86.1845, subject to the following additional provisions:

(i) In-use verification test vehicles may be procured from customers or may be owned by, 

or under the control of the manufacturer, provided that the vehicle has accumulated 

mileage in typical operation on public streets and has received typical maintenance.

(ii) In lieu of procuring in-use verification test vehicles that have a minimum odometer 

reading of 50,000 miles, a manufacturer may demonstrate to the satisfaction of the 

Agency that, based on owner survey data, the average mileage accumulated after 4 years 

for a given test group is less than 50,000 miles. The Agency may approve procurement of 

in-use verification test vehicles that have a lower minimum odometer reading based on 

such data.

(iii) The provisions of § 86.1845–04(c)(2) that require one vehicle of each test group 

during high mileage in-use verification testing to have a minimum odometer mileage do 

not apply.

(iv) Manufacturers intending to use the provisions of this paragraph (c) shall submit to 

the Agency a plan detailing how these provisions will be met before submitting an 

application for certification for the subject vehicles.

(d) Operationally independent manufacturers. Manufacturers may submit an application 

to EPA requesting treatment as an operationally independent manufacturer. A 

manufacturer that is granted operationally independent status may qualify for all the 

regulatory provisions of this subpart that apply for small-volume manufacturers on the 

basis of its own vehicle production and/or sales volumes, and would not require 

aggregation with related manufacturers. In this paragraph (d), the term “related 
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manufacturer(s)” means manufacturers that would qualify for aggregation under the 

requirements of paragraph (b)(3) of this section.

* * * * *

195. Section 86.1843-01 is amended by revising paragraph (g) to read as follows:

§ 86.1843-01 General information requirements.

* * * * *

(g) Recordkeeping. (1) This subpart includes various requirements to record data or other 

information. Unless we specify otherwise, store these records in any format and on any

media and keep them readily available for eight years after you send an associated 

application for certification, or eight years after you generate the data if they do not 

support an application for certification. You must promptly send us organized, written 

records in English upon request. We may review them at any time.

(2) Upon written request by the Administrator, a manufacturer shall submit any

information as described in § 86.1844–01 within 15 business days. A manufacturer may

request the Administrator to grant an extension. The request must clearly indicate the 

circumstances necessitating the extension.

* * * * *

196. Section 86.1844-01 is amended by revising paragraphs (a), (d)(7), (d)(8), (d)(9), 

(d)(11), and (d)(16)(i) introductory text, removing paragraph (d)(16)(iv), and adding 

paragraph (e)(7) to read as follows:

§ 86.1844-01 Information requirements: Application for certification and submittal 

of information upon request.

(a) All the information listed in this section must be submitted to the Agency according to 

the requirements specified in § 86.1843; however, we may ask you to include less 

information than we specify, as long as you keep the specified records. 

* * * * *

(d) * * *

(7) A comprehensive list of all test results, including official certification levels, and the 

applicable intermediate and full useful life emission standards to which the test group is 

to be certified as required in § 86.1829. Include the following additional information 

related to testing:

(i) Include a comparison of drive cycle energy and target cycle energy relative to both 

inertia and road load forces as specified in 40 CFR 1066.425 for each drive cycle or test 

phase, as appropriate.

(ii) For gasoline-fueled Tier 3 vehicles, identify the method of accounting for ethanol in 

determining evaporative emissions, as described in § 86.1813. 

(iii) Identify any aspects of testing for which the regulations obligate EPA testing to 

conform to your selection of test methods.

(8) A statement that all applicable vehicles will conform to the emission standards for 

which emission data is not being provided, as allowed under § 86.1806 or § 86.1829. The 

statement shall clearly identify the standards for which emission testing was not 

completed.
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(9) Information describing each emission control diagnostic system required by § 

86.1806, including all of the following:

(i) A description of the functional operation characteristics of the diagnostic system, with 

additional information demonstrating that the system meets the requirements specified in 

§ 86.1806. Include all testing and demonstration data submitted to the California Air 

Resources Board for certification.

(ii) The general method of detecting malfunctions for each emission-related powertrain 

component.

(iii) Any deficiencies, including resolution plans and schedules. 

(iv) A statement that the diagnostic system is adequate for the performance warranty test 

described in 40 CFR part 85, subpart W. 

(v) For vehicles certified to meet the leak standard in § 86.1813, a description of the 

anticipated test procedure. The description must include, at a minimum, a method for 

accessing the fuel system for measurements and a method for pressurizing the fuel 

system to perform the procedure specified in 40 CFR 1066.985. The recommended test 

method must include at least two separate points for accessing the fuel system, with 

additional access points as appropriate for multiple fuel tanks and multiple evaporative or 

refueling canisters.

* * * * *

(11) A list of all auxiliary emission control devices (AECD) installed on any applicable 

vehicles, including a justification for each AECD, the parameters they sense and control, 

a detailed justification of each AECD that results in a reduction in effectiveness of the 

emission control system, and rationale for why it is not a defeat device as defined under § 

86.1809. The following specific provisions apply for AECDs:

(i) For any AECD uniquely used at high altitudes, EPA may request engineering emission 

data to quantify any emission impact and validity of the AECD. 

(ii) For any AECD uniquely used on multi-fuel vehicles when operated on fuels other 

than gasoline, EPA may request engineering emission data to quantify any emission 

impact and validity of the AECD.

(iii) For Tier 3 vehicles with spark-ignition engines, describe how AECDs are designed to 

comply with the requirements of § 86.1811-17(d). Identify which components need 

protection through enrichment strategies; describe the temperature limitations for those 

components; and describe how the enrichment strategy corresponds to those temperature 

limitations. We may also require manufacturers to submit this information for 

certification related to Tier 2 vehicles.

* * * * *

(16) * * *

(i) A statement indicating that the manufacturer has conducted an engineering analysis of 

the complete exhaust system to ensure that the exhaust system has been designed–

* * * * *

(e) * * *

(7) The results of any production vehicle evaluation testing required for OBD systems 

under § 86.1806.

* * * * *
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§ 86.1845-01 [Removed]

197. Remove § 86.1845-01.

198. Section 86.1845-04 is amended by revising paragraphs (a)(1), (a)(3), (b)(3) 

introductory text, (b)(4), (b)(5), (b)(6), (b)(7), (c), and (f) to read as follows:

§ 86.1845-04 Manufacturer in-use verification testing requirements.

(a) * * *

(1) Manufacturers of LDV, LDT, MDPV and complete HDV must test, or cause to have 

tested, a specified number of vehicles. Such testing must be conducted in accordance 

with the provisions of this section. 

* * * * *

(3) The following provisions apply regarding the possibility of residual effects from 

varying fuel sulfur levels:

(i) Vehicles certified to Tier 3 standards under § 86.1811 must always measure emissions 

over the FTP, then over the HFET (if applicable), then over the US06 portion of the 

SFTP. If a Tier 3 vehicle meets all the applicable emission standards except the FTP or 

HFET emission standard for NMOG+NOx, and a fuel sample from the tested vehicle 

(representing the as-received condition) has a measured fuel sulfur level exceeding 15 

ppm when measured as described in 40 CFR 1065.710, the manufacturer may repeat the 

FTP and HFET measurements and use the new emission values as the official results for 

that vehicle. For all other cases of testing Tier 3 vehicles, measured emission levels from 

the first test will be considered the official results for the test vehicle, regardless of any 

test results from additional test runs. Where repeat testing is allowed, the vehicle may

operate for up to two US06 cycles (with or without measurement) before repeating the 

FTP and HFET measurements. The repeat measurements must include both FTP and 

HFET, even if the vehicle failed only one of those tests, unless the HFET is not required 

for a particular vehicle. Tier 3 vehicles may not undergo any other vehicle 

preconditioning to eliminate fuel sulfur effects on the emission control system, unless we 

approve it in advance.

(ii) Upon a manufacturer's written request, prior to in-use testing, that presents 

information to EPA regarding pre-conditioning procedures designed solely to remove the 

effects of high sulfur in gasoline from vehicles produced through the 2007 model year, 

EPA will consider allowing such procedures on a case-by-case basis. EPA's decision will 

apply to manufacturer in-use testing conducted under this section and to any in-use 

testing conducted by EPA. Such procedures are not available for complete HDV. For 

model year 2007 and later Tier 2 vehicles, this provision can be used only in American 

Samoa, Guam, and the Commonwealth of the Northern Mariana Islands, and then only if 

low sulfur gasoline is determined by the Administrator to be unavailable in that specific 

location.

(b) * * *

(3) Number of test vehicles. For each test group, the minimum number of vehicles that 

must be tested is specified in Table S04–06 and Table S04–07 of this paragraph (b)(3). 

After testing the minimum number of vehicles of a specific test group as specified in 
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Page 758 of 1039

Table S04–06 or S04–07 of this paragraph (b)(3), a manufacturer may test additional 

vehicles upon request and approval by the Agency prior to the initiation of the additional 

testing. Any additional testing must be completed within the testing completion 

requirements shown in § 86.1845–04(b)(4). The request and Agency approval (if any) 

shall apply to test groups on a case by case basis and apply only to testing under this 

paragraph. Separate approval will be required to test additional vehicles under paragraph 

(c) of this section. In addition to any testing that is required under Table S04–06 and 

Table S04–07, a manufacturer shall test one vehicle from each evaporative/refueling 

family for evaporative/refueling emissions. If a manufacturer believes it is unable to 

procure the test vehicles necessary to test the required number of vehicles in a test group, 

the manufacturer may request, subject to Administrator approval, a decreased sample size 

for that test group. The request shall include a description of the methods the 

manufacturer has used to procure the required number of vehicles. The approval of any 

such request, and the substitution of an alternative sample size requirement for the test 

group, will be based on a review of the procurement efforts made by the manufacturer to 

determine if all reasonable steps have been taken to procure the required test group size. 

Tables S04–06 and S04–07 follow:

* * * * *

(4) Completion of testing. Testing of the vehicles in a test group and 

evaporative/refueling family must be completed within 12 months of the end of 

production of that test group (or evaporative/refueling family) for that model year.

(5) Testing. (i) Each test vehicle of a test group shall be tested in accordance with the 

FTP and the US06 portion of the SFTP as described in subpart B of this part, when such 

test vehicle is tested for compliance with applicable exhaust emission standards under 

this subpart. Test vehicles subject to applicable exhaust CO2 emission standards under 

this subpart shall also be tested in accordance with the HFET as described in part 600, 

subpart B, of this chapter.

(ii) Manufacturers must measure PM emissions over the FTP and US06 driving schedules 

for at least 50 percent of the vehicles tested under paragraph (b)(5)(i) of this section.

(iii) Starting with model year 2018 vehicles, manufacturers must demonstrate compliance 

with the Tier 3 leak standard specified in § 86.1813, if applicable, as described in this 

paragraph (b)(5)(iii). Manufacturers must evaluate each vehicle tested under paragraph 

(b)(5)(i) of this section, except that leak testing is not required for vehicles tested under 

paragraph (b)(5)(iv) of this section for diurnal emissions. In addition, manufacturers 

must evaluate at least one vehicle from each leak family for a given model year. 

Manufacturers may rely on OBD monitoring instead of testing as follows:

(A) A vehicle is considered to pass the leak test if the OBD system completed a leak 

check within the previous 750 miles of driving without showing a leak fault code.

(B) Whether or not a vehicle’s OBD system has completed a leak check within the 

previous 750 miles of driving, the manufacturer may operate the vehicle as needed to 

force the OBD system to perform a leak check. If the OBD leak check does not show a 

leak fault, the vehicle is considered to pass the leak test.

(C) If the most recent OBD leak check from paragraph (b)(5)(iii)(A) or (B) of this section 

shows a leak-related fault code as specified in § 86.1806-17(b), the vehicle is presumed 
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Page 759 of 1039

to have failed the leak test. Manufacturers may perform the leak measurement procedure 

described in 40 CFR 1066.985 for an official result to replace the finding from the OBD 

leak check.

(D) Manufacturers may not perform repeat OBD checks or leak measurements to override a failure under paragraph (b)(5)(iii)(C) of this section.

(iv) For nongaseous-fueled vehicles, one test vehicle of each evaporative/refueling family 

shall be tested in accordance with the supplemental 2-diurnal-plus-hot-soak evaporative 

emission and refueling emission procedures described in subpart B of this part, when 

such test vehicle is tested for compliance with applicable evaporative emission and 

refueling standards under this subpart. For gaseous-fueled vehicles, one test vehicle of 

each evaporative/refueling family shall be tested in accordance with the 3-diurnal-plushot-soak evaporative emission and refueling emission procedures described in subpart B 

of this part, when such test vehicle is tested for compliance with applicable evaporative 

emission and refueling standards under this subpart. The test vehicles tested to fulfill the 

evaporative/refueling testing requirement of this paragraph (b)(5)(ii) will be counted 

when determining compliance with the minimum number of vehicles as specified in 

Table S04–06 and Table S04–07 in paragraph (b)(3) of this section for testing under 

paragraph (b)(5)(i) of this section only if the vehicle is also tested for exhaust emissions 

under the requirements of paragraph (b)(5)(i) of this section.

(6) Each test vehicle not rejected based on the criteria specified in appendix II to this 

subpart shall be tested in as-received condition. 

(7) A manufacturer may conduct subsequent diagnostic maintenance and/or testing of any

vehicle. Any such maintenance and/or testing shall be reported to the Agency as specified 

in § 86.1847.

(c) High-mileage testing —(1) Test groups. Testing must be conducted for each test 

group.

(2) Vehicle mileage. All test vehicles must have a minimum odometer mileage of 50,000 

miles. At least one vehicle of each test group must have a minimum odometer mileage of 

105,000 miles or 75 percent of the full useful life mileage, whichever is less. See § 

86.1838–01(c)(2) for small-volume manufacturer mileage requirements.

(3) Number of test vehicles. For each test group, the minimum number of vehicles that 

must be tested is specified in Table S04–06 and Table S04–07 in paragraph (b)(3) of this 

section. After testing the minimum number of vehicles of a specific test group as 

specified in Table S04–06 and Table S04–07 in paragraph (b)(3) of this section, a 

manufacturer may test additional vehicles upon request and approval by the Agency prior 

to the initiation of the additional testing. Any additional testing must be completed within 

the testing completion requirements shown in § 86.1845–04(c)(4). The request and 

Agency approval (if any) shall apply to test groups on a case by case basis and apply only 

to testing under this paragraph (c). In addition to any testing that is required under Table 

S04–06 and Table S04–07, a manufacturer shall test one vehicle from each 

evaporative/refueling family for evaporative/refueling emissions. If a manufacturer 

believes it is unable to procure the test vehicles necessary to test the required number of 

vehicles in a test group as specified in Table S04–06 or Table S04–07, the manufacturer 

may request, subject to Administrator approval, a decreased sample size for that test 
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Page 760 of 1039

group. The request shall include a description of the methods the manufacturer has used 

to procure the required number of vehicles. The approval of any such request, and the 

substitution of an alternative sample size requirement for the test group, will be based on 

a review of the procurement efforts made by the manufacturer to determine if all 

reasonable steps have been taken to procure the required test group size.

(4) Initiation and completion of testing. Testing of a test group (or evaporative refueling 

family) must commence within 4 years of the end of production of the test group (or 

evaporative/refueling family) and be completed within 5 years of the end of production of 

the test group (or evaporative/refueling family).

(5) Testing. (i) Each test vehicle shall be tested in accordance with the FTP and the US06 

portion of the SFTP as described in subpart B of this part when such test vehicle is tested 

for compliance with applicable exhaust emission standards under this subpart. Test 

vehicles subject to applicable exhaust CO2 emission standards under this subpart shall 

also be tested in accordance with the HFET as described in 40 CFR part 600, subpart B. 

One test vehicle from each test group shall be tested over the FTP at high altitude. The 

test vehicle tested at high altitude is not required to be one of the same test vehicles tested 

at low altitude. The test vehicle tested at high altitude is counted when determining the 

compliance with the requirements shown in Table S04–06 and Table S04–07 in 

paragraph (b)(3) of this section or the expanded sample size as provided for in this 

paragraph (c).

(ii) Manufacturers must measure PM emissions over the FTP and US06 driving schedules 

for at least 50 percent of the vehicles tested under paragraph (c)(5)(i) of this section.

(iii) Starting with model year 2018 vehicles, manufacturers must evaluate each vehicle 

tested under paragraph (c)(5)(i) of this section to demonstrate compliance with the Tier 3 

leak standard specified in § 86.1813, except that leak testing is not required for vehicles 

tested under paragraph (c)(5)(iv) of this section for diurnal emissions. In addition, 

manufacturers must evaluate at least one vehicle from each leak family for a given model 

year. Manufacturers may rely on OBD monitoring instead of testing as described in 

paragraph (c)(5)(iii) of this section.

(iv) For nongaseous-fueled vehicles, one test vehicle of each evaporative/refueling family 

shall be tested in accordance with the supplemental 2-diurnal-plus-hot-soak evaporative 

emission procedures described in subpart B of this part, when such test vehicle is tested 

for compliance with applicable evaporative emission and refueling standards under this 

subpart. For gaseous-fueled vehicles, one test vehicle of each evaporative/refueling 

family shall be tested in accordance with the 3-diurnal-plus-hot-soak evaporative 

emission procedures described in subpart B of this part, when such test vehicle is tested 

for compliance with applicable evaporative emission and refueling standards under this 

subpart. The test vehicles tested to fulfill the evaporative/refueling testing requirement of 

this paragraph (b)(5)(ii) will be counted when determining compliance with the minimum 

number of vehicles as specified in Table S04–06 and table S04–07 in paragraph (b)(3) of 

this section for testing under paragraph (b)(5)(i) of this section only if the vehicle is also 

tested for exhaust emissions under the requirements of paragraph (b)(5)(i) of this section.

(6) Test condition. Each test vehicle not rejected based on the criteria specified in 

appendix II to this subpart shall be tested in as-received condition.
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Page 761 of 1039

(7) Diagnostic maintenance. A manufacturer may conduct subsequent diagnostic 

maintenance and/or testing on any vehicle. Any such maintenance and/or testing shall be 

reported to the Agency as specified in § 86.1847–01.

* * * * *

(f)(1) A manufacturer must conduct in-use testing on a test group by determining NMOG 

exhaust emissions as described in 40 CFR 1066.635.

(2) For flexible-fueled vehicles certified to NMOG (or NMOG+NOx) standards, the 

manufacturer may ask for EPA approval to demonstrate compliance using an equivalent 

NMOG emission result calculated from a ratio of ethanol NMOG exhaust emissions to 

gasoline NMHC exhaust emissions. Ethanol NMOG exhaust emissions are measured 

values from testing with the ethanol test fuel, expressed as NMOG. Gasoline NMHC 

exhaust emissions are measured values from testing with the gasoline test fuel, expressed 

as NMHC. This ratio must be established during certification for each emission-data 

vehicle for the applicable test group. Use good engineering judgment to establish a 

different ratio for each duty cycle or test interval as appropriate. Identify the ratio values 

you develop under this paragraph (f)(1) and describe the duty cycle or test interval to 

which they apply in the Part II application for certification. Calculate the equivalent 

NMOG emission result by multiplying the measured gasoline NMHC exhaust emissions 

for a given duty cycle or test interval by the appropriate ratio. 

(3) If the manufacturer measures NMOG as described in 40 CFR 1066.635(a), it must 

also measure and report HCHO emissions. As an alternative to measuring the HCHO 

content, if the manufacturer measures NMOG as permitted in 40 CFR 1066.635(c), the 

Administrator may approve, upon submission of supporting data by a manufacturer, the 

use of HCHO to NMHC ratios. To request the use of HCHO to NMHC ratios, the 

manufacturer must establish during certification testing the ratio of measured HCHO 

exhaust emissions to measured NMHC exhaust emissions for each emission-`data vehicle 

for the applicable test group. The results must be submitted to the Administrator with the 

Part II application for certification. Following approval of the application for 

certification, the manufacturer may conduct in-use testing on the test group by measuring 

NMHC exhaust emissions rather than HCHO exhaust emissions. The measured NMHC 

exhaust emissions must be multiplied by the HCHO to NMHC ratio submitted in the 

application for certification for the test group to determine the equivalent HCHO exhaust 

emission values for the test vehicle. The equivalent HCHO exhaust emission values must 

be compared to the HCHO exhaust emission standard applicable to the test group.

199. Section 86.1846-01 is revised to read as follows:

§ 86.1846-01 Manufacturer in-use confirmatory testing requirements.

(a) General requirements. (1) Manufacturers must test, or cause testing to be conducted, 

under this section when the emission levels shown by a test group sample from testing 

under § 86.1845 exceeds the criteria specified in paragraph (b) of this section. The testing 

required under this section applies separately to each test group and at each test point 

(low and high mileage) that meets the specified criteria. The testing requirements apply

separately for each model year. These provisions apply to heavy-duty vehicles starting 
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Page 762 of 1039

with model year 2007. These provisions do not apply to emissions of CO2, CH4, and 

N2O.

(2) The provisions of § 86.1845-04(a)(3) regarding fuel sulfur effects apply equally to 

testing under this section. 

(b) Criteria for additional testing. (1) A manufacturer shall test a test group or a subset of 

a test group as described in paragraph (j) of this section when the results from testing 

conducted under § 86.1845 show mean exhaust emissions for that test group of any 

pollutant(s) (except CO2, CH4, and N2O) to be equal to or greater than 1.30 times the 

applicable in-use standard and a failure rate, among the test group vehicles, for the 

corresponding pollutant(s) of fifty percent or greater.

(i) Additional testing is not required under this paragraph (b)(1) based on Supplemental 

FTP testing or evaporative/refueling testing. Testing conducted at high altitude under the 

requirements of § 86.1845-04(b) will be included in determining if a test group meets the 

criteria triggering testing required under this section.

(ii) The vehicle tested under the requirements of § 86.1845–04(c)(2) with a minimum 

odometer miles of 75% of useful life will not be included in determining if a test group 

meets the triggering criteria.

(iii) The SFTP composite emission levels shall include the IUVP FTP emissions, the 

IUVP US06 emissions, and the values from the SC03 Air Conditioning EDV certification 

test (without DFs applied). The calculations shall be made using the equations prescribed 

in § 86.164. If more than one set of certification SC03 data exists (due to running change 

testing or other reasons), the manufacturer shall choose the SC03 result to use in the 

calculation from among those data sets using good engineering judgment.

(2) If fewer than 50 percent of the vehicles from a leak family pass either the leak test or 

the diurnal test under § 86.1845, EPA may require further leak testing under this 

paragraph (b)(2). Testing under this section must include five vehicles from the family. 

If all five of these vehicles fail the test, the manufacturer must test five additional 

vehicles. 

EPA will determine whether to require further leak testing under this section after 

providing the manufacturer an opportunity to discuss the results, including consideration 

of any of the following information, or other items that may be relevant: 

(i) Detailed system design, calibration, and operating information, technical explanations 

as to why the individual vehicles tested failed the leak standard.

(ii) Comparison of the subject vehicles to other similar models from the same 

manufacturer. 

(iii) Data or other information on owner complaints, technical service bulletins, service 

campaigns, special policy warranty programs, warranty repair data, state I/M data, and 

data available from other manufacturer-specific programs or initiatives.

(iv) Evaporative emission test data on any individual vehicles that did not pass leak 

testing during IUVP. 

(c) Useful life. Vehicles tested under the provisions of this section must be within the 

useful life specified for the emission standards which were exceeded in the testing under 

§ 86.1845. Testing should be within the useful life specified, subject to sections 207(c)(5) 

and (c)(6) of the Clean Air Act where applicable.
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(d) Number of test vehicles. A manufacturer must test a minimum of ten vehicles of the 

test group or Agency-designated subset. A manufacturer may, at the manufacturer's 

discretion, test more than ten vehicles under this paragraph for a specific test group or 

Agency-designated subset. If a manufacturer chooses to test more than the required ten 

vehicles, all testing must be completed within the time designated in the testing 

completion requirements of paragraph (g) of this section. Any vehicles which are 

eliminated from the sample either prior to or subsequent to testing, or any vehicles for 

which test results are determined to be void, must be replaced in order that the final 

sample of vehicles for which test results acceptable to the Agency are available equals a 

minimum of ten vehicles. A manufacturer may cease testing with a sample of five 

vehicles if the results of the first five vehicles tested show mean emissions for each 

pollutant to be less than 75.0 percent of the applicable standard, with no vehicles 

exceeding the applicable standard for any pollutant.

(e) Emission testing. Each test vehicle of a test group or Agency-designated subset shall 

be tested in accordance with the FTP and/or the SFTP (whichever of these tests 

performed under § 86.1845 produces emission levels requiring testing under this section) 

as described in subpart B of this part, when such test vehicle is tested for compliance with 

applicable exhaust emission standards under this subpart.

(f) Geographical limitations. (1) Test groups or Agency-designated subsets certified to 

50-state standards: For low altitude testing no more than 50 percent of the test vehicles 

may be procured from California. The test vehicles procured from the 49 state area must 

be procured from a location with a heating degree day 30 year annual average equal to or 

greater than 4000.

(2) Test groups or Agency-designated subsets certified to 49 state standards: For lowaltitude testing all vehicles shall be procured from a location with a heating degree day 30 

year annual average equal to or greater than 4000.

(3) Vehicles procured for high altitude testing may be procured from any area provided 

that the vehicle's primary area of operation was above 4000 feet.

(g) Testing. Testing required under this section must commence within three months of 

completion of the testing under § 86.1845 which triggered the confirmatory testing and 

must be completed within seven months of the completion of the testing which triggered 

the confirmatory testing. Any industry review of the results obtained under § 86.1845 and 

any additional vehicle procurement and/or testing which takes place under the provisions 

of § 86.1845 which the industry believes may affect the triggering of required 

confirmatory testing must take place within the three month period. The data and the 

manufacturers reasoning for reconsideration of the data must be provided to the Agency

within the three month period.

(h) Limit on manufacturer conducted testing. For each manufacturer, the maximum 

number of test group(s) (or Agency-designated subset(s)) of each model year for which 

testing under this section shall be required is limited to 50 percent of the total number of 

test groups of each model year required to be tested by each manufacturer as prescribed 

in § 86.1845, rounded to the next highest whole number where appropriate. For each 

manufacturer with only one test group under § 86.1845, such manufacturer shall have a 
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Page 764 of 1039

maximum potential testing requirement under this section of one test group (or Agencydesignated subset) per model year.

(i) Testing plan. Prior to beginning in-use confirmatory testing the manufacturer must, 

after consultation with the Agency, submit a written plan describing the details of the 

vehicle procurement, maintenance, and testing procedures (not otherwise specified by 

regulation) it intends to use. EPA must approve the test plan before the manufacturer 

may start further testing.

(j) Testing a subset. EPA may designate a subset of the test group based on transmission 

type for testing under this section in lieu of testing the entire test group when the results 

for the entire test group from testing conducted under § 86.1845 show mean emissions 

and a failure rate which meet these criteria for additional testing.

200. Section 86.1848-10 is amended by revising paragraph (c)(7) to read as follows:

§ 86.1848-10 Compliance with emission standards for the purpose of certification.

* * * * *

(c) * * *

(7) All certificates of conformity issued are conditional upon compliance with all the 

provisions of §§ 86.1811 through 86.1816 and §§ 86.1860 through 86.1862 both during 

and after model year production. The manufacturer bears the burden of establishing to the 

satisfaction of the Administrator that the terms and conditions upon which each 

certificate was issued were satisfied. For recall and warranty purposes, vehicles not 

covered by a certificate of conformity will continue to be held to the standards stated or 

referenced in the certificate that otherwise would have applied to the vehicles.

(i) Failure to meet the applicable fleet average standard will be considered to be a failure 

to satisfy the terms and conditions upon which the certificate was issued and the vehicles 

sold in violation of the fleet average standard will not be covered by the certificate.

(ii) Failure to comply fully with the prohibition against selling credits that it has not 

generated or that are not available, as specified in § 86.1861, will be considered a failure 

to satisfy the terms and conditions upon which the certificate was issued and the vehicles 

sold in violation of this prohibition will not be covered by the certificate.

(iii) Failure to comply fully with the phase-in requirements of §§ 86.1811 through 

86.1816 will be considered a failure to satisfy the terms and conditions upon which the 

certificate was issued and the vehicles sold that do not comply with the applicable 

standards, up to the number needed to comply, will not be covered by the certificate.

* * * * *

201. A new § 86.1860-17 is added to subpart S to read as follows:

§ 86.1860-17 How to comply with the Tier 3 fleet-average standards.

(a) You must show that you meet the applicable fleet-average NMOG+NOx standards 

from §§ 86.1811 and 86.1816 and the fleet-average evaporative emission standards from 

§ 86.1813 as described in this section. Note that separate fleet-average calculations are 

required for the FTP and SFTP exhaust emission standards under § 86.1811. 

(b) Calculate your fleet-average value for each model year for all vehicle models subject 

to a separate fleet-average standard using the following equation, rounded to the nearest 
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Page 765 of 1039

0.001 g/mile for NMOG+NOx emissions and the nearest 0.001 g/test for evaporative 

emissions:

i i

i 1

total

( )

b

N FEL

Fleet average value

N









Where:

i = A counter associated with each separate Tier 3 test group or evaporative family.

b = The number of separate Tier 3 test groups or evaporative families from a given 

averaging set to which you certify your vehicles.

Ni = The actual nationwide sales for the model year for test group or evaporative family i. 

Include allowances for evaporative emissions as described in § 86.1813.

FELi = The FEL selected for test group or evaporative family i. Disregard any separate 

standards that apply for in-use testing or for testing under high-altitude conditions.

Ntotal = The actual nationwide sales for the model year for all your Tier 3 vehicles from 

the averaging set, except as described in paragraph (c) of this section. The pool of 

vehicle models included in Ntotal may vary by model year, and it may be different for 

evaporative standards, FTP exhaust standards, and SFTP exhaust standards in a given 

model year. 

(c) Do not include any of the following vehicles to calculate your fleet-average value:

(1) Vehicles that you do not certify to the standards of this part because they are 

permanently exempted under 40 CFR part 85 or part 1068.

(2) Exported vehicles.

(3) Vehicles excluded under § 86.1801.

(4) For model year 2017, do not include vehicle sales in California or the section 177 

states for calculating the fleet average value for evaporative emissions.

(d) Except as specified in paragraph (e) of this section, your calculated fleet-average 

value may not exceed the corresponding fleet-average standard for the model year.

(e) You may generate or use emission credits related to your calculated fleet-average 

value as follows:

(1) You may generate emission credits as described in § 86.1861 if your fleet-average 

value is below the corresponding fleet-average standard.

(2) You may use emission credits as described in § 86.1861 if your fleet-average value is 

above the corresponding fleet-average standard. Except as specified in paragraph (e)(3) 

of this section, you must use enough credits for each model year to show that your 

adjusted fleet average value does not exceed the fleet-average standard.

(3) The following provisions apply if you do not have enough emission credits to 

demonstrate compliance with a fleet-average standard in a given model year:

(i) You may have a credit deficit for up to three model years within an averaging set 

under § 86.1861-17(c). You may not bank emission credits with respect to a given 

emission standard during a model year in which you have a credit deficit in the same 

averaging set. If you fail to meet the fleet-average standard for four consecutive model 

years, the vehicles causing you to exceed the fleet-average standard will be considered 

not covered by the certificate of conformity. You will be subject to penalties on an 

individual-vehicle basis for sale of vehicles not covered by a certificate of conformity.
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Page 766 of 1039

(ii) You must notify us in writing how you plan to eliminate the credit deficit within the 

specified time frame. If we determine that your plan is unreasonable or unrealistic, we 

may deny an application for certification for a test group or evaporative family if its bin 

standard or FEL would increase your credit deficit. We may determine that your plan is 

unreasonable or unrealistic based on a consideration of past and projected use of specific 

technologies, the historical sales mix of your vehicle models, your commitment to limit 

sales of higher-emission vehicles, and expected access to traded credits. We may also 

consider your plan unreasonable if your fleet-average emission level increases relative to 

the first model year of a credit deficit or any later model year. We may require that you 

send us interim reports describing your progress toward resolving your credit deficit over 

the course of a model year. 

(f) If the applicable bin standards and FELs for all your vehicle models are at or below a 

corresponding fleet-average standard for a given model year, and you do not want to 

generate emission credits, you may omit the calculations described in this section.

(g) For purposes of calculating the statute of limitations, the following actions are all

considered to occur at the expiration of the deadline for offsetting a deficit as specified in 

paragraph (e)(3) of this section:

(1) Failing to meet the requirements of paragraph (e)(3) of this section.

(2) Failing to satisfy the conditions upon which a certificate was issued relative to 

offsetting a deficit.

(3) Selling, offering for sale, introducing or delivering into U.S. commerce, or importing 

vehicles that are found not to be covered by a certificate as a result of failing to offset a 

deficit.

202. A new § 86.1861-17 is added to subpart S to read as follows:

§ 86.1861-17 How do the NMOG+NOx and evaporative emission credit programs 

work?

You may use emission credits for purposes of certification to show compliance with the 

applicable fleet-average NMOG+NOx standards from §§ 86.1811 and 86.1816 and the 

fleet-average evaporative emission standards from § 86.1813 as described in 40 CFR part 

1037, subpart H, with certain exceptions and clarifications as specified in this section. 

MDPVs are subject to the same provisions of this section that apply to LDT4.

(a) Calculate emission credits as described in this paragraph (a) instead of using the 

provisions of 40 CFR 1037.705. Calculate positive or negative emission credits relative 

to the applicable fleet-average standard. Calculate positive emission credits if your fleetaverage level is below the standard. Calculate negative emission credits if your fleetaverage value is above the standard. Calculate credits separately for each type of 

standard and for each averaging set. Calculate emission credits using the following 

equation, rounded to the nearest whole number:

Emissioncredit   Volume [ ] Fleet average standard Fleet averagevalue

Where:

Emission credit = The positive or negative credit for each discrete fleet-average standard, 

in units of vehicle-grams per mile for NMOG+NOx and vehicle-grams per test for 

evaporative emissions.
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Page 767 of 1039

Volume = Sales volume in a given model year from the collection of test groups or 

evaporative families covered by the fleet-average value, as described in § 86.1860.

(b) The following restrictions apply instead of those specified in 40 CFR 1037.740:

(1) Except as specified in paragraph (b)(3) of this section, emission credits may be 

exchanged only within an averaging set, as follows:

(i) HDV represent a separate averaging set with respect to all emission standards.

(ii) LDV and LDT certified to standards based on a useful life of 150,000 miles and 15 

years together represent a single averaging set with respect to NMOG+NOx emission 

standards. Note that FTP and SFTP credits are not interchangeable.

(iii) LDV and LDT1 certified to standards based on a useful life of 120,000 miles and 10 

years together represent a single averaging set with respect to NMOG+NOx emission 

standards. Note that FTP and SFTP credits are not interchangeable.

(iv) The following separate averaging sets apply for evaporative emission standards:

(A) LDV and LDT1 together represent a single averaging set.

(B) LDT2 represents a single averaging set.

(C) HLDT represents a single averaging set.

(D) HDV represents a single averaging set.

(2) You may exchange evaporative emission credits across averaging sets as follows if 

you need additional credits to offset a deficit after the final year of maintaining deficit 

credits as allowed under paragraph (c) of this section:

(i) You may exchange LDV/LDT1 and LDT2 emission credits.

(ii) You may exchange HLDT and HDV emission credits.

(3) Except as specified in paragraph (b)(4) of this section, credits expire after five years. 

For example, credits you generate in model year 2018 may be used only through model 

year 2023.

(4) For the Tier 3 declining fleet-average FTP and SFTP emission standards for 

NMOG+NOx described in § 86.1811-17(b)(8), credits generated in model years 2017 

through 2024 expire after eight years, or after model year 2030, whichever comes first; 

however, these credits may not be traded after five years. This extended credit life also 

applies for small-volume manufacturers generating credits under § 86.1811-17(h)(1) in 

model years 2022 through 2024. Note that the longer credit life does not apply for 

heavy-duty vehicles, for vehicles certified under the alternate phase-in described in § 

86.1811-17(b)(9), or for vehicles generating early Tier 3 credits under § 86.1811-

17(b)(11) in model year 2017.

(c) The credit-deficit provisions 40 CFR 1037.745 apply to the NMOG+NOx and 

evaporative emission standards for Tier 3 vehicles.

(d) The reporting and recordkeeping provisions of § 86.1862 apply instead of those 

specified in 40 CFR 1037.730 and 1037.735.

(e) The provisions of 40 CFR 1037.645 do not apply.

203. Section 86.1862-04 is revised to read as follows:

§ 86.1862-04 Maintenance of records and submittal of information relevant to 

compliance with fleet-average standards.
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(a) Overview. This section describes reporting and recordkeeping requirements for 

vehicles subject to the following standards:

(1) Tier 2 NOx emission standard for LDV and LDT in § 86.1811-04.

(2) Tier 3 FTP emission standard for NMOG+NOx for LDV and LDT in § 86.1811. 

(3) Tier 3 SFTP emission standard for NMOG+NOx for LDV and LDT (including 

MDPV) in § 86.1811. 

(4) Tier 3 evaporative emission standards in § 86.1813. 

(5) Tier 3 FTP emission standard for NMOG+NOx for HDV (other than MDPV) in § 

86.1816.

(6) Cold temperature NMHC standards in § 86.1811.

(b) Maintenance of records. (1) The manufacturer producing any vehicles subject to a 

fleet-average standard under this subpart must establish and maintain all the following 

information in organized and indexed records for each model year:

(i) Model year.

(ii) Applicable fleet-average standard.

(iii) Calculated fleet-average value.

(iv) All values used in calculating the fleet-average value achieved.

(2) The manufacturer producing any vehicle subject to the provisions in this section must 

keep all the following information for each vehicle:

(i) Model year.

(ii) Applicable fleet-average standard.

(iii) EPA test group or evaporative family, as applicable.

(iv) Assembly plant.

(v) Vehicle identification number.

(vi) The FEL and the fleet-average standard to which the vehicle is certified.

(vii) Information on the point of first sale, including the purchaser, city, and state.

(3) The manufacturer must retain all records required to be maintained under this section 

for a period of eight years from the due date for the annual report. Records may be stored 

in any format and on any media, as long as manufacturers can promptly send EPA 

organized written records in English if we ask for them. Manufacturers must keep records 

readily available as EPA may review them at any time.

(4) The Administrator may require the manufacturer to retain additional records or submit 

information not specifically required by this section.

(5) EPA may void ab initio a certificate of conformity for a vehicle certified to emission 

standards as set forth or otherwise referenced in this subpart for which the manufacturer 

fails to retain the records required in this section, to provide such information to the 

Administrator upon request, or to submit the reports required in this section in the 

specified time period.

(c) Reporting. (1) Each manufacturer must submit an annual report. Except as provided in 

paragraph (b)(2) of this section, the annual report must contain, for each applicable fleet 

average standard, the fleet average value achieved, all values required to calculate the 

fleet-average value, the number of credits generated or debits incurred, all the values 

required to calculate the credits or debits, and sufficient information to show compliance 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 769 of 1039

with all phase-in requirements, if applicable. The annual report must also contain the 

resulting balance of credits or debits.

(2) When a manufacturer calculates compliance with the fleet-average standard using the 

provisions in § 86.1860–04(c)(2) or § 86.1860-17(f), the annual report must state that the 

manufacturer has elected to use such provision and must contain the fleet-average 

standard as the fleet-average value for that model year.

(3) For each applicable fleet-average standard, the annual report must also include 

documentation on all credit transactions the manufacturer has engaged in since those 

included in the last report. Information for each transaction must include all the following 

information:

(i) Name of credit provider.

(ii) Name of credit recipient.

(iii) Date the transfer occurred.

(iv) Quantity of credits transferred.

(v) Model year in which the credits were earned.

(4) Unless a manufacturer reports the data required by this section in the annual 

production report required under § 86.1844–01(e) and subsequent model year provisions, 

a manufacturer must submit an annual report for each model year after production ends 

for all affected vehicles produced by the manufacturer subject to the provisions of this 

subpart and no later than May 1 of the calendar year following the given model year. 

Annual reports must be submitted to: Director, Compliance Division, U.S. Environmental 

Protection Agency, 2000 Traverwood, Ann Arbor, Michigan 48105.

(5) Failure by a manufacturer to submit the annual report in the specified time period for 

all vehicles subject to the provisions in this section is a violation of Clean Air Act section 

203(a)(1) (42 U.S.C 7522(a)(1)) for each subject vehicle produced by that manufacturer.

(6) If EPA or the manufacturer determines that a reporting error occurred on an annual 

report previously submitted to EPA, the manufacturer's credit or debit calculations will be 

recalculated. EPA may void erroneous credits, unless transferred, and must adjust 

erroneous debits. In the case of transferred erroneous credits, EPA must adjust the selling 

manufacturer's credit or debit balance to reflect the sale of such credits and any resulting 

generation of debits.

(d) Notice of opportunity for hearing. Any voiding of the certificate under paragraph 

(a)(6) of this section will be made only after EPA has offered the manufacturer concerned 

an opportunity for a hearing conducted in accordance with § 86.614 for light-duty

vehicles and light-duty trucks and with 40 CFR part 1068, subpart G, for heavy-duty

vehicles. 

204. Section 86.1863-07 is amended by adding introductory text to read as follows:

§ 86.1863-07 Optional chassis certification for diesel vehicles.

This section does not apply for vehicles certified to the Tier 3 standards in § 86.1816-18, 

including those vehicles that certify to the Tier 3 standards before model year 2018.

* * * * *

205. Section 86.1864-10 is amended by revising paragraph (p) to read as follows:
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§ 86.1864-10 How to comply with the fleet average cold temperature NMHC 

standards.

* * * * *

(p) Reporting and recordkeeping. Keep records and submit information for 

demonstrating compliance with the fleet average cold temperature NMHC standard as 

described in § 86.1862-04.

206. Section 86.1868-12 is amended by revising paragraphs (f)(1) and (g)(1) to read as 

follows: 

§ 86.1868–12 CO2 credits for improving the efficiency of air conditioning systems.

* * * * *

(f) * * *

(1) The manufacturer shall perform the AC17 test specified in 40 CFR 1066.845 on each 

unique air conditioning system design and vehicle platform combination for which the 

manufacturer intends to accrue air conditioning efficiency credits. The manufacturer must 

test at least one unique air conditioning system within each vehicle platform in a model 

year, unless all unique air conditioning systems within a vehicle platform have been 

previously tested. A unique air conditioning system design is a system with unique or 

substantially different component designs or types and/or system control strategies (e.g., 

fixed displacement vs. variable displacement compressors, orifice tube vs. thermostatic 

expansion valve, single vs. dual evaporator, etc.). In the first year of such testing, the 

tested vehicle configuration shall be the highest production vehicle configuration within 

each platform. In subsequent model years the manufacturer must test other unique air 

conditioning systems within the vehicle platform, proceeding from the highest production 

untested system until all unique air conditioning systems within the platform have been 

tested, or until the vehicle platform experiences a major redesign. Whenever a new 

unique air conditioning system is tested, the highest production configuration using that 

system shall be the vehicle selected for testing. Air conditioning system designs which 

have similar cooling capacity, component types, and control strategies, yet differ in terms 

of compressor pulley ratios or condenser or evaporator surface areas will not be 

considered to be unique system designs. The test results from one unique system design 

may represent all variants of that design. Manufacturers must use good engineering 

judgment to identify the unique air conditioning system designs which will require AC17 

testing in subsequent model years. Results must be reported separately for all four phases 

(two phases with air conditioning off and two phases with air conditioning on) of the test 

to the Environmental Protection Agency, and the results of the calculations required in 40 

CFR 1066.845 must also be reported. In each subsequent model year additional air 

conditioning system designs, if such systems exist, within a vehicle platform that is 

generating air conditioning credits must be tested using the AC17 procedure. When all 

unique air conditioning system designs within a platform have been tested, no additional 

testing is required within that platform, and credits may be carried over to subsequent 

model years until there is a significant change in the platform design, at which point a 

new sequence of testing must be initiated. No more than one vehicle from each creditgenerating platform is required to be tested in each model year.
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

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* * * * *

(g) * * *

(1) For each air conditioning system selected by the manufacturer to generate air 

conditioning efficiency credits, the manufacturer shall perform the AC17 Air 

Conditioning Efficiency Test Procedure specified in 40 CFR 1066.845, according to the 

requirements of this paragraph (g).

* * * * *

207. Appendix I to Part 86 is amended by revising the appendix heading, paragraph (a) 

before the table, and paragraphs (b) and (c), and removing and reserving paragraph (d) to 

read as follows: 

Appendix I to Part 86—Dynamometer Schedules

(a) EPA light-duty urban dynamometer driving schedule (UDDS). This driving schedule 

is also known as the LA-4 cycle.

(1) The driving schedule in this paragraph (a) applies for light-duty vehicles, light-duty

trucks, and heavy-duty vehicles certified under subpart S of this part.

(2) The driving schedule in this paragraph (a) applies for motorcycles with engine 

displacement at or above 170 cc. Calculate the speed-versus-time sequence in kilometers 

per hour by multiplying the listed speed by 1.6 and rounding to the nearest 0.1 kilometers 

per hour.

(3) The driving schedule follows:

* * * * *

(b) EPA driving schedule for motorcycles with engine displacement below 170 cc. Use 

the driving schedule specified in paragraph (a)(2) of this appendix, except that the 

schedule specified in this paragraph (b) applies for the portion of the driving schedule 

from 164 to 332 seconds.

Speed Versus Time Sequence

Time 

(sec.)

Speed 

(kph)

164 3.4

165 6.8

166 10.3

167 13.7

168 17.1

169 20.5

170 23.0

171 25.2

172 26.7

173 27.4

174 26.6

175 26.0

176 25.6

177 25.9

178 26.1

179 26.3

180 26.7

181 28.2

182 27.5

183 24.9

184 23.5

185 20.1

186 18.3

187 17.8

188 18.8

189 19.3

190 20.7

191 23.0

192 25.4

193 28.3

194 31.6

195 34.7

196 37.5

197 38.6

198 40.7

199 42.0

200 43.6

201 45.1

202 46.7

203 47.7

204 48.5

205 49.2

206 49.2

207 49.0

208 48.9

209 48.7

210 48.7

211 48.7

212 48.7

213 48.7

214 48.9

215 49.1

216 49.6

217 50.2

218 50.9

219 51.3

220 51.8

221 52.4

222 52.8

223 53.4

224 54.1

225 55.1

226 56.0

227 56.6

228 56.9

229 57.0

230 56.9

231 56.6

232 56.6

233 56.8

234 57.1

235 57.5

236 57.7
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237 58.1

238 58.3

239 58.6

240 58.7

241 58.7

242 58.5

243 58.5

244 58.5

245 58.5

246 58.5

247 58.5

248 58.4

249 58.1

250 57.8

251 57.1

252 56.6

253 56.2

254 55.9

255 55.6

256 55.5

257 55.8

258 55.9

259 56.0

260 56.0

261 55.7

262 55.3

263 54.9

264 54.5

265 54.0

266 54.3

267 53.9

268 53.8

269 53.6

270 53.4

271 53.5

272 53.7

273 54.0

274 54.4

275 54.9

276 55.4

277 55.9

278 56.9

279 57.4

280 57.6

281 58.0

282 58.0

283 57.8

284 57.2

285 56.5

286 55.5

287 54.4

288 53.4

289 53.4

290 53.4

291 52.9

292 51.9

293 51.8

294 51.9

295 51.8

296 51.4

297 51.3

298 51.3

299 51.3

300 50.9

301 50.3

302 49.8

303 48.9

304 47.8

305 46.6

306 45.4

307 44.1

308 43.0

309 41.8

310 39.9

311 38.3

312 36.5

313 35.0

314 33.7

315 32.6

316 31.7

317 31.6

318 31.1

319 30.0

320 28.5

321 25.7

322 22.3

323 20.8

324 19.8

325 19.2

326 17.6

327 16.1

328 12.9

329 11.2

330 8.3

331 4.9

332 1.5

(c) EPA driving schedule for class 3 heavy-duty vehicles. This driving schedule is also known 

as the LA-92 cycle.

Time 

(sec.)

Speed 

(mph)

1 0.0

2 0.0

3 0.0

4 0.0

5 0.0

6 0.0

7 0.0

8 0.0

9 0.0

10 0.0

11 0.0

12 0.0

13 0.0

14 0.0

15 0.0

16 0.0

17 0.0

18 0.0

19 0.0

20 0.0

21 1.2

22 4.2

23 7.3

24 8.8

25 10.8

26 12.3

27 13.1

28 12.3

29 12.3

30 11.5

31 11.5

32 11.1

33 11.1

34 11.1

35 13.1

36 15.0

37 16.9

38 16.9

39 16.1

40 15.7

41 15.4

42 15.0

43 13.8

44 10.8

45 8.4

46 6.1

47 4.2

48 3.5

49 3.5

50 1.5

51 0.0

52 0.0

53 0.0

54 0.0

55 0.0

56 0.0

57 0.0

58 0.0

59 0.0

60 0.0

61 0.0

62 0.0

63 1.2

64 3.5

65 7.7

66 11.1

67 13.8

68 16.5

69 18.4

70 20.4

71 20.7

72 19.6

73 17.3

74 12.3

75 8.1

76 6.1

77 9.6

78 12.7

79 15.7

80 18.0

81 20.4

82 21.9

83 23.4

84 23.8

85 24.6

86 25.0

87 26.1
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88 26.1

89 26.9

90 26.9

91 26.9

92 26.5

93 25.7

94 21.9

95 16.5

96 10.0

97 4.6

98 1.5

99 0.4

100 0.0

101 0.0

102 0.0

103 0.0

104 0.0

105 0.0

106 0.0

107 0.0

108 0.4

109 1.2

110 1.9

111 3.8

112 7.7

113 11.5

114 14.6

115 18.0

116 21.5

117 25.0

118 28.4

119 30.7

120 31.9

121 32.3

122 32.3

123 31.9

124 30.3

125 28.0

126 24.2

127 20.0

128 16.1

129 11.5

130 8.1

131 5.0

132 3.5

133 1.9

134 0.0

135 0.0

136 0.0

137 0.0

138 0.0

139 0.0

140 0.0

141 0.0

142 0.0

143 1.5

144 6.9

145 12.7

146 16.5

147 20.0

148 23.0

149 25.7

150 28.0

151 30.7

152 32.6

153 34.2

154 35.3

155 36.9

156 36.9

157 37.2

158 37.6

159 37.6

160 37.6

161 37.2

162 37.2

163 36.9

164 36.5

165 36.5

166 34.9

167 33.4

168 31.9

169 29.2

170 25.0

171 25.0

172 26.1

173 27.6

174 29.2

175 31.1

176 32.3

177 34.2

178 34.9

179 35.7

180 36.5

181 36.9

182 36.9

183 37.2

184 37.6

185 37.2

186 37.6

187 38.0

188 38.4

189 39.2

190 39.6

191 39.9

192 40.7

193 40.3

194 41.1

195 41.1

196 40.7

197 31.9

198 23.9

199 15.9

200 7.9

201 2.7

202 0.4

203 0.4

204 2.7

205 3.8

206 3.8

207 1.5

208 0.0

209 0.0

210 0.0

211 0.0

212 0.0

213 0.0

214 0.0

215 0.0

216 0.0

217 0.0

218 0.0

219 0.0

220 0.0

221 0.0

222 0.0

223 0.0

224 0.0

225 0.0

226 0.0

227 0.0

228 0.0

229 0.0

230 0.0

231 0.0

232 0.0

233 0.0

234 0.0

235 0.0

236 0.0

237 0.0

238 1.5

239 5.0

240 8.8

241 11.5

242 14.2

243 15.4

244 16.1

245 16.1

246 16.9

247 16.5

248 16.9

249 18.0

250 19.2

251 20.4

252 20.4

253 21.1

254 21.1

255 22.3

256 23.0

257 23.8

258 24.2

259 24.6

260 25.0

261 25.7

262 25.7

263 26.5

264 27.6

265 28.4

266 29.2

267 30.3

268 31.1

269 31.1

270 30.7

271 31.1

272 29.6

273 29.2

274 29.2

275 28.8

276 28.0

277 23.0

278 21.1

279 21.5

280 20.7

281 20.7

282 19.6

283 16.5

284 13.1

285 9.6

286 7.3

287 3.8

288 0.8

289 0.0

290 0.0

291 0.0

292 0.0
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 774 of 1039

293 0.0

294 0.0

295 0.0

296 0.0

297 0.0

298 0.0

299 0.0

300 0.0

301 0.0

302 0.0

303 0.0

304 0.0

305 0.0

306 0.0

307 0.0

308 0.0

309 0.0

310 0.0

311 0.0

312 0.0

313 0.4

314 2.7

315 7.3

316 11.5

317 15.4

318 18.4

319 20.7

320 24.2

321 26.9

322 29.6

323 31.1

324 32.6

325 33.8

326 34.9

327 36.9

328 39.2

329 41.1

330 43.0

331 43.8

332 44.5

333 45.3

334 45.3

335 44.9

336 44.5

337 43.8

338 43.4

339 42.6

340 41.9

341 41.5

342 40.7

343 40.3

344 41.1

345 41.5

346 42.6

347 43.4

348 44.2

349 44.9

350 45.7

351 46.5

352 46.8

353 47.2

354 48.0

355 47.6

356 48.4

357 48.0

358 47.2

359 46.1

360 45.7

361 44.9

362 44.2

363 43.8

364 44.5

365 44.9

366 45.3

367 46.5

368 48.0

369 48.8

370 49.5

371 49.9

372 49.9

373 49.9

374 49.5

375 49.5

376 48.8

377 48.8

378 48.8

379 48.4

380 48.8

381 49.5

382 50.3

383 50.7

384 51.8

385 52.6

386 53.4

387 54.1

388 55.3

389 55.3

390 56.1

391 56.4

392 56.4

393 56.4

394 57.2

395 56.8

396 57.6

397 57.6

398 57.6

399 58.0

400 58.0

401 58.4

402 58.4

403 58.8

404 59.1

405 58.8

406 58.8

407 58.0

408 58.0

409 57.6

410 57.6

411 57.6

412 57.6

413 57.6

414 59.1

415 59.5

416 59.9

417 60.3

418 60.3

419 61.1

420 60.3

421 59.9

422 59.5

423 59.1

424 59.1

425 59.5

426 59.5

427 59.5

428 59.9

429 60.3

430 60.7

431 60.7

432 61.4

433 61.8

434 61.8

435 61.8

436 61.8

437 61.1

438 60.7

439 60.3

440 60.3

441 60.3

442 59.5

443 58.8

444 59.1

445 58.8

446 58.8

447 58.8

448 58.4

449 58.0

450 58.0

451 58.0

452 58.4

453 59.1

454 59.5

455 59.9

456 59.9

457 60.3

458 61.1

459 61.1

460 61.1

461 61.4

462 61.4

463 61.1

464 60.7

465 59.9

466 59.1

467 59.1

468 59.1

469 59.9

470 59.5

471 59.9

472 58.8

473 58.0

474 57.6

475 56.8

476 56.1

477 55.3

478 54.1

479 52.6

480 49.2

481 46.1

482 43.0

483 37.2

484 29.6

485 21.5

486 16.5

487 15.7

488 18.4

489 21.5

490 25.0

491 27.3

492 29.2

493 30.7

494 31.5

495 31.1

496 31.1

497 30.3
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 775 of 1039

498 30.0

499 30.0

500 29.6

501 30.0

502 28.8

503 28.8

504 28.0

505 28.4

506 28.0

507 28.4

508 28.4

509 28.8

510 28.4

511 28.4

512 28.0

513 26.5

514 24.2

515 22.7

516 20.4

517 17.7

518 15.7

519 13.1

520 10.8

521 8.4

522 7.3

523 5.0

524 3.8

525 3.5

526 1.9

527 0.8

528 0.0

529 0.0

530 0.0

531 0.8

532 1.9

533 3.8

534 6.9

535 9.6

536 11.1

537 11.1

538 10.4

539 8.8

540 9.2

541 10.0

542 10.4

543 10.4

544 5.4

545 1.9

546 0.0

547 0.0

548 0.0

549 0.0

550 0.0

551 0.0

552 0.0

553 0.0

554 0.0

555 0.0

556 0.0

557 0.0

558 0.0

559 0.0

560 0.0

561 0.0

562 0.0

563 0.0

564 0.0

565 0.0

566 0.0

567 0.0

568 0.0

569 0.0

570 0.0

571 0.0

572 0.4

573 1.5

574 3.5

575 6.1

576 10.4

577 14.2

578 16.9

579 19.2

580 20.0

581 21.5

582 23.4

583 24.6

584 24.2

585 20.0

586 16.9

587 13.4

588 13.4

589 15.7

590 18.4

591 21.1

592 23.4

593 25.3

594 27.6

595 28.8

596 30.3

597 30.7

598 31.5

599 31.1

600 31.1

601 30.3

602 30.3

603 30.3

604 30.7

605 31.1

606 32.3

607 32.6

608 32.6

609 32.6

610 31.1

611 26.9

612 22.3

613 18.0

614 13.8

615 9.6

616 4.6

617 6.1

618 10.0

619 14.2

620 17.3

621 20.0

622 21.5

623 22.3

624 22.3

625 22.3

626 22.3

627 23.0

628 23.0

629 22.7

630 22.3

631 21.9

632 22.7

633 23.8

634 25.0

635 25.3

636 25.7

637 26.5

638 26.9

639 27.3

640 28.0

641 29.2

642 30.0

643 30.0

644 29.6

645 29.6

646 28.8

647 28.4

648 28.0

649 27.3

650 25.7

651 24.6

652 25.0

653 26.5

654 28.0

655 29.6

656 30.7

657 32.3

658 33.0

659 34.2

660 34.6

661 35.3

662 36.1

663 36.1

664 36.9

665 36.9

666 37.6

667 37.6

668 38.4

669 38.0

670 37.6

671 37.6

672 37.2

673 36.9

674 36.1

675 35.7

676 36.1

677 35.7

678 35.7

679 35.7

680 36.1

681 36.1

682 35.7

683 35.7

684 34.9

685 34.6

686 34.2

687 33.8

688 33.4

689 33.0

690 30.3

691 29.2

692 28.4

693 25.0

694 21.1

695 16.9

696 13.4

697 13.1

698 12.3

699 12.7

700 15.7

701 19.2

702 22.3
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 776 of 1039

703 24.6

704 25.7

705 26.5

706 26.5

707 26.9

708 27.3

709 27.3

710 27.6

711 28.4

712 28.8

713 28.8

714 29.2

715 28.8

716 28.8

717 28.0

718 28.0

719 27.6

720 26.5

721 24.6

722 20.7

723 16.5

724 15.0

725 14.2

726 14.2

727 13.8

728 13.8

729 11.9

730 8.4

731 4.2

732 1.2

733 0.0

734 0.0

735 0.0

736 0.0

737 0.0

738 0.0

739 0.0

740 0.0

741 0.0

742 0.0

743 0.0

744 0.0

745 0.0

746 0.0

747 0.0

748 0.0

749 0.0

750 0.0

751 0.0

752 0.0

753 0.0

754 0.0

755 0.0

756 0.0

757 0.0

758 0.0

759 0.0

760 0.0

761 0.0

762 0.0

763 1.5

764 5.4

765 9.2

766 11.5

767 14.6

768 17.3

769 19.2

770 21.1

771 20.7

772 20.7

773 19.6

774 18.4

775 16.9

776 16.9

777 16.5

778 16.9

779 16.9

780 16.9

781 17.3

782 19.2

783 20.4

784 21.1

785 22.3

786 22.3

787 22.7

788 22.3

789 22.7

790 22.3

791 23.8

792 25.7

793 27.6

794 29.6

795 30.0

796 29.2

797 27.6

798 25.0

799 23.8

800 23.4

801 24.2

802 23.4

803 23.0

804 20.4

805 18.8

806 17.3

807 15.0

808 13.1

809 9.2

810 6.9

811 4.6

812 4.6

813 4.6

814 4.2

815 5.4

816 4.6

817 3.5

818 2.3

819 2.3

820 1.9

821 3.1

822 6.1

823 4.6

824 2.7

825 2.3

826 2.3

827 3.1

828 4.2

829 3.5

830 3.8

831 4.2

832 3.5

833 3.5

834 3.5

835 4.6

836 5.8

837 3.5

838 0.8

839 3.5

840 3.8

841 2.3

842 0.0

843 1.2

844 6.9

845 13.8

846 18.8

847 23.8

848 27.3

849 30.7

850 33.8

851 37.6

852 40.7

853 43.8

854 46.1

855 48.0

856 49.5

857 51.5

858 53.0

859 54.5

860 55.7

861 56.8

862 58.0

863 59.1

864 60.3

865 61.1

866 61.8

867 61.8

868 61.8

869 61.8

870 62.6

871 63.4

872 63.0

873 63.0

874 62.6

875 61.8

876 61.8

877 62.2

878 62.2

879 62.6

880 63.7

881 64.5

882 64.9

883 66.0

884 66.0

885 66.8

886 66.4

887 66.8

888 67.2

889 66.4

890 66.4

891 66.0

892 65.7

893 65.7

894 66.4

895 66.0

896 65.7

897 65.3

898 65.3

899 64.5

900 64.5

901 64.1

902 63.7

903 63.7

904 63.7

905 64.5

906 64.5

907 64.9
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

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908 64.5

909 64.1

910 64.9

911 65.3

912 65.3

913 65.3

914 64.1

915 63.4

916 63.0

917 63.4

918 64.1

919 64.9

920 65.3

921 64.5

922 64.1

923 63.4

924 63.7

925 63.4

926 63.4

927 63.4

928 63.4

929 63.7

930 64.5

931 65.3

932 64.9

933 63.7

934 63.0

935 59.9

936 55.3

937 50.7

938 49.2

939 48.0

940 46.1

941 44.2

942 41.1

943 39.9

944 36.1

945 32.6

946 29.2

947 24.6

948 20.7

949 19.2

950 16.5

951 15.0

952 11.9

953 9.6

954 8.4

955 5.8

956 1.2

957 0.0

958 0.0

959 0.0

960 1.2

961 3.1

962 5.0

963 8.4

964 11.5

965 14.6

966 16.9

967 18.8

968 21.1

969 23.8

970 26.5

971 28.0

972 29.6

973 30.7

974 32.6

975 34.2

976 35.3

977 36.1

978 36.9

979 38.0

980 38.0

981 38.0

982 38.0

983 38.0

984 37.2

985 36.9

986 36.1

987 35.7

988 34.9

989 34.9

990 33.8

991 31.5

992 28.8

993 25.7

994 24.6

995 23.4

996 22.3

997 21.5

998 20.0

999 20.0

1000 19.2

1001 19.2

1002 18.0

1003 11.9

1004 6.9

1005 2.7

1006 0.8

1007 0.4

1008 0.0

1009 0.0

1010 0.0

1011 0.0

1012 0.0

1013 0.0

1014 0.0

1015 0.0

1016 0.0

1017 0.0

1018 0.0

1019 0.0

1020 0.0

1021 0.0

1022 0.0

1023 0.4

1024 2.7

1025 6.1

1026 9.2

1027 11.5

1028 14.2

1029 16.1

1030 18.0

1031 20.0

1032 21.5

1033 23.0

1034 24.2

1035 25.0

1036 25.7

1037 26.9

1038 27.6

1039 27.6

1040 28.4

1041 29.2

1042 29.2

1043 30.0

1044 29.6

1045 29.6

1046 28.8

1047 28.0

1048 23.8

1049 18.8

1050 11.9

1051 6.1

1052 1.5

1053 1.5

1054 4.2

1055 8.1

1056 10.4

1057 13.1

1058 15.4

1059 18.0

1060 20.4

1061 23.0

1062 25.3

1063 27.3

1064 28.8

1065 30.3

1066 31.1

1067 32.3

1068 31.9

1069 32.3

1070 31.9

1071 31.1

1072 28.8

1073 25.0

1074 22.7

1075 18.8

1076 15.4

1077 13.4

1078 11.9

1079 8.8

1080 5.0

1081 1.9

1082 2.3

1083 2.7

1084 3.5

1085 6.5

1086 10.8

1087 13.8

1088 16.1

1089 18.4

1090 20.4

1091 21.9

1092 21.9

1093 20.7

1094 17.3

1095 13.1

1096 9.6

1097 8.8

1098 10.8

1099 12.7

1100 14.2

1101 14.6

1102 13.1

1103 11.1

1104 11.1

1105 11.1

1106 13.1

1107 15.7

1108 18.4

1109 20.7

1110 23.8

1111 25.7

1112 28.0
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

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1113 30.0

1114 31.1

1115 32.3

1116 34.2

1117 35.7

1118 36.9

1119 38.8

1120 40.3

1121 41.5

1122 42.2

1123 43.0

1124 43.8

1125 43.8

1126 43.4

1127 43.0

1128 42.2

1129 41.9

1130 41.5

1131 41.9

1132 41.9

1133 41.9

1134 42.2

1135 42.6

1136 42.6

1137 42.6

1138 42.6

1139 42.6

1140 42.6

1141 42.6

1142 42.2

1143 43.0

1144 43.4

1145 43.0

1146 42.6

1147 41.9

1148 40.7

1149 36.9

1150 32.6

1151 28.0

1152 23.4

1153 18.4

1154 14.6

1155 12.3

1156 9.2

1157 5.8

1158 1.9

1159 0.4

1160 0.0

1161 0.0

1162 0.0

1163 0.0

1164 0.0

1165 0.4

1166 4.2

1167 9.2

1168 11.9

1169 14.2

1170 15.7

1171 15.0

1172 14.2

1173 13.4

1174 13.8

1175 14.6

1176 14.6

1177 14.2

1178 16.1

1179 15.7

1180 15.7

1181 14.6

1182 13.1

1183 10.0

1184 7.3

1185 3.5

1186 0.8

1187 0.0

1188 0.0

1189 0.0

1190 0.0

1191 0.4

1192 2.7

1193 7.3

1194 11.5

1195 15.4

1196 19.2

1197 21.9

1198 23.8

1199 25.0

1200 26.1

1201 27.3

1202 28.8

1203 30.0

1204 29.6

1205 29.6

1206 28.8

1207 26.1

1208 22.3

1209 19.2

1210 16.5

1211 12.7

1212 9.6

1213 6.9

1214 4.2

1215 2.3

1216 0.8

1217 0.0

1218 0.0

1219 0.0

1220 0.0

1221 0.0

1222 0.0

1223 0.0

1224 0.0

1225 0.0

1226 0.0

1227 0.0

1228 0.0

1229 0.0

1230 0.0

1231 0.0

1232 0.0

1233 0.0

1234 0.0

1235 0.0

1236 0.0

1237 0.0

1238 0.0

1239 0.0

1240 3.5

1241 10.4

1242 15.4

1243 17.3

1244 17.3

1245 18.4

1246 21.5

1247 24.6

1248 27.3

1249 30.0

1250 31.5

1251 31.9

1252 32.6

1253 33.4

1254 34.9

1255 36.5

1256 37.6

1257 39.2

1258 40.3

1259 40.7

1260 41.1

1261 40.7

1262 40.7

1263 40.7

1264 41.5

1265 42.6

1266 43.0

1267 44.5

1268 45.3

1269 45.3

1270 44.9

1271 43.4

1272 40.3

1273 38.0

1274 36.1

1275 36.5

1276 38.0

1277 39.2

1278 40.7

1279 42.2

1280 43.4

1281 44.9

1282 45.7

1283 46.1

1284 46.8

1285 46.5

1286 46.5

1287 46.5

1288 46.1

1289 46.1

1290 46.1

1291 46.8

1292 47.6

1293 48.0

1294 48.4

1295 48.0

1296 48.0

1297 47.2

1298 46.5

1299 46.8

1300 47.2

1301 48.4

1302 48.4

1303 48.8

1304 48.4

1305 47.6

1306 46.5

1307 44.2

1308 42.2

1309 41.5

1310 41.1

1311 40.7

1312 40.3

1313 39.6

1314 39.2

1315 38.8

1316 38.0

1317 37.6
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

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1318 37.2

1319 36.5

1320 34.6

1321 31.5

1322 29.6

1323 29.2

1324 28.8

1325 28.8

1326 28.0

1327 28.0

1328 28.4

1329 29.6

1330 30.0

1331 30.3

1332 29.2

1333 26.5

1334 25.3

1335 25.0

1336 24.6

1337 24.6

1338 25.3

1339 26.1

1340 27.3

1341 28.4

1342 29.2

1343 29.2

1344 29.6

1345 30.0

1346 31.1

1347 32.6

1348 33.8

1349 34.6

1350 34.9

1351 34.6

1352 34.9

1353 34.6

1354 34.9

1355 34.9

1356 34.9

1357 34.2

1358 33.8

1359 32.6

1360 31.5

1361 30.0

1362 28.8

1363 27.3

1364 23.8

1365 23.0

1366 23.0

1367 22.3

1368 20.4

1369 18.8

1370 17.7

1371 16.1

1372 14.6

1373 12.7

1374 11.1

1375 9.2

1376 8.8

1377 7.3

1378 6.1

1379 5.0

1380 4.2

1381 3.5

1382 2.7

1383 2.3

1384 1.5

1385 1.2

1386 0.0

1387 1.2

1388 4.2

1389 7.3

1390 8.8

1391 10.8

1392 12.3

1393 13.1

1394 12.3

1395 12.3

1396 11.5

1397 11.5

1398 11.1

1399 11.1

1400 11.1

1401 13.1

1402 15.0

1403 16.9

1404 16.9

1405 16.1

1406 15.7

1407 15.4

1408 15.0

1409 13.8

1410 10.8

1411 8.4

1412 6.1

1413 4.2

1414 3.5

1415 3.5

1416 1.5

1417 0.0

1418 0.0

1419 0.0

1420 0.0

1421 0.0

1422 0.0

1423 0.0

1424 0.0

1425 0.0

1426 0.0

1427 0.0

1428 0.0

1429 0.0

1430 0.0

1431 0.0

1432 0.0

1433 0.0

1434 0.0

1435 0.0

1436 0.0

1437 0.0

1438 0.0

1439 0.0

1440 0.0

1441 0.0

1442 0.0

1443 0.0

1444 0.0

1445 0.0

1446 0.0

1447 0.0

1448 0.0

1449 0.0

1450 0.0

1451 0.0

1452 0.0

1453 0.0

1454 0.0

1455 0.0

1456 1.2

1457 4.2

1458 7.3

1459 8.8

1460 10.8

1461 12.3

1462 13.1

1463 12.3

1464 12.3

1465 11.5

1466 11.5

1467 11.1

1468 11.1

1469 11.1

1470 13.1

1471 15.0

1472 16.9

1473 16.9

1474 16.1

1475 15.7

1476 15.4

1477 15.0

1478 13.8

1479 10.8

1480 8.4

1481 6.1

1482 4.2

1483 3.5

1484 3.5

1485 1.5

1486 0.0

1487 0.0

1488 0.0

1489 0.0

1490 0.0

1491 0.0

1492 0.0

1493 0.0

1494 0.0

1495 0.0

1496 0.0

1497 0.0

1498 1.2

1499 3.5

1500 7.7

1501 11.1

1502 13.8

1503 16.5

1504 18.4

1505 20.4

1506 20.7

1507 19.6

1508 17.3

1509 12.3

1510 8.1

1511 6.1

1512 9.6

1513 12.7

1514 15.7

1515 18.0

1516 20.4

1517 21.9

1518 23.4

1519 23.8

1520 24.6

1521 25.0

1522 26.1
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

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1523 26.1

1524 26.9

1525 26.9

1526 26.9

1527 26.5

1528 25.7

1529 21.9

1530 16.5

1531 10.0

1532 4.6

1533 1.5

1534 0.4

1535 0.0

1536 0.0

1537 0.0

1538 0.0

1539 0.0

1540 0.0

1541 0.0

1542 0.0

1543 0.4

1544 1.2

1545 1.9

1546 3.8

1547 7.7

1548 11.5

1549 14.6

1550 18.0

1551 21.5

1552 25.0

1553 28.4

1554 30.7

1555 31.9

1556 32.3

1557 32.3

1558 31.9

1559 30.3

1560 28.0

1561 24.2

1562 20.0

1563 16.1

1564 11.5

1565 8.1

1566 5.0

1567 3.5

1568 1.9

1569 0.0

1570 0.0

1571 0.0

1572 0.0

1573 0.0

1574 0.0

1575 0.0

1576 0.0

1577 0.0

1578 1.5

1579 6.9

1580 12.7

1581 16.5

1582 20.0

1583 23.0

1584 25.7

1585 28.0

1586 30.7

1587 32.6

1588 34.2

1589 35.3

1590 36.9

1591 36.9

1592 37.2

1593 37.6

1594 37.6

1595 37.6

1596 37.2

1597 37.2

1598 36.9

1599 36.5

1600 36.5

1601 34.9

1602 33.4

1603 31.9

1604 29.2

1605 25.0

1606 25.0

1607 26.1

1608 27.6

1609 29.2

1610 31.1

1611 32.3

1612 34.2

1613 34.9

1614 35.7

1615 36.5

1616 36.9

1617 36.9

1618 37.2

1619 37.6

1620 37.2

1621 37.6

1622 38.0

1623 38.4

1624 39.2

1625 39.6

1626 39.9

1627 40.7

1628 40.3

1629 41.1

1630 41.1

1631 40.7

1632 31.9

1633 23.9

1634 15.9

1635 7.9

1636 2.7

1637 0.4

1638 0.4

1639 2.7

1640 3.8

1641 3.8

1642 1.5

1643 0.0

1644 0.0

1645 0.0

1646 0.0

1647 0.0

1648 0.0

1649 0.0

1650 0.0

1651 0.0

1652 0.0

1653 0.0

1654 0.0

1655 0.0

1656 0.0

1657 0.0

1658 0.0

1659 0.0

1660 0.0

1661 0.0

1662 0.0

1663 0.0

1664 0.0

1665 0.0

1666 0.0

1667 0.0

1668 0.0

1669 0.0

1670 0.0

1671 0.0

1672 0.0

1673 1.5

1674 5.0

1675 8.8

1676 11.5

1677 14.2

1678 15.4

1679 16.1

1680 16.1

1681 16.9

1682 16.5

1683 16.9

1684 18.0

1685 19.2

1686 20.4

1687 20.4

1688 21.1

1689 21.1

1690 22.3

1691 23.0

1692 23.8

1693 24.2

1694 24.6

1695 25.0

1696 25.7

1697 25.7

1698 26.5

1699 27.6

1700 28.4

1701 29.2

1702 30.3

1703 31.1

1704 31.1

1705 30.7

1706 31.1

1707 29.6

1708 29.2

1709 29.2

1710 28.8

1711 28.0

1712 23.0

1713 21.1

1714 21.5

1715 20.7

1716 20.7

1717 19.6

1718 16.5

1719 13.1

1720 9.6

1721 7.3

1722 3.8

1723 0.8

1724 0.0

1725 0.0

1726 0.0

1727 0.0
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 781 of 1039

1728 0.0

1729 0.0

1730 0.0

1731 0.0

1732 0.0

1733 0.0

1734 0.0

1735 0.0

(d) [Reserved]

* * * * *

Appendix XIII through Appendix XVIII to Part 86—[Removed]

208. Appendix XIII through Appendix XVIII to Part 86 are removed.

PART 600—FUEL ECONOMY AND GREENHOUSE GAS EXHAUST

EMISSIONS OF MOTOR VEHICLES

209. The authority citation for part 600 continues to read as follows:

Authority: 49 U.S.C. 32901—23919q, Pub. L. 109–58.

Subpart A—[Amended]

210. Section 600.001 is amended by adding paragraph (e) to read as follows:

§ 600.001 General applicability.

* * * * *

(e) You. The term “you” in this part refers to manufacturers subject to the requirements of 

this part.

211. Section 600.002 is amended by revising the definitions for “Alcohol” and 

“Alcohol-fueled automobile” and adding a definition for “We (us, our)” in alphabetical 

order to read as follows:

§ 600.002 Definitions.

* * * * *

Alcohol means a mixture containing 85 percent or more by volume methanol, 

denatured ethanol, or other alcohols, in any combination.

Alcohol-fueled automobile means an automobile designed to operate on alcohol, but 

not on gasoline.

* * * * *

We (us, our) means the Administrator of the Environmental Protection Agency and 

any authorized representatives.

* * * * *

212. Section 600.011 is amended by revising paragraphs (b), (c)(2), and (c)(3) to read 

as follows:

§ 600.011 Incorporation by reference.

* * * * *
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 782 of 1039

(b) ASTM International material. The following documents are available from ASTM 

International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA, 19428-

2959, (610) 832-9585, or http://www.astm.org/.

(1) ASTM D975-13a, Standard Specification for Diesel Fuel Oils, approved December 1, 

2013, IBR approved for § 600.107–08(b). 

(2) ASTM D1298-12b, Standard Test Method for Density, Relative Density, or API

Gravity of Crude Petroleum and Liquid Petroleum Products by Hydrometer Method, 

approved June 1, 2012, IBR approved for §§ 600.113–12(f) and (g) and 600.510-12(g).

(3) ASTM D1945-03 (Reapproved 2010), Standard Test Method for Analysis of Natural 

Gas By Gas Chromatography, approved January 1, 2010, IBR approved for § 600.113-

12(f).

(4) ASTM D3338/D3338M-09, Standard Test Method for Estimation of Net Heat of 

Combustion of Aviation Fuels, approved April 15, 2009, IBR approved for § 600.113-

12(f).

(5) ASTM D3343-05 (Reapproved 2010), Standard Test Method for Estimation of 

Hydrogen Content of Aviation Fuels, approved October 1, 2010, IBR approved for § 

600.113-12(f).

(c) * * *

(2) SAE J1634, Battery Electric Vehicle Energy Consumption and Range Test Procedure, 

revised October 2012, IBR approved for §§ 600.116-12(a) and 600.311-12(j) and (k).

(3) SAE J1711, Recommended Practice for Measuring the Exhaust Emissions and Fuel 

Economy of Hybrid-Electric Vehicles, Including Plug-In Hybrid Vehicles, revised June 

2010, IBR approved for §§ 600.114-12(c) and (f), 600.116-12(b) and (c), and 600.311-

12(c), (j), and (k).

* * * * *

Subpart B—[Amended]

213. Section 600.111-08 is revised to read as follows:

§ 600.111-08 Test procedures.

This section describes test procedures for the FTP, highway fuel economy test (HFET), 

US06, SC03, and the cold temperature FTP tests. Perform testing according to test 

procedures and other requirements contained in this part 600 and in 40 CFR parts 86 and 

1066, including the provisions of 40 CFR part 86, subparts B, C, and S. Manufacturers 

may certify vehicles based on data collected according to previously published test 

procedures for model years through 2021. In addition, we may approve the use of 

previously published test procedures for later model years as an alternative procedure 

under 40 CFR 1066.10(c). See 40 CFR 86.101 and 86.201 for detailed provisions related 

to this transition. 

(a) FTP testing procedures. Conduct FTP testing as described in 40 CFR 1066.810 

through 1066.820 . You may omit evaporative emission measurements for testing under 

this part 600 unless we specifically require it. 

(b) Highway fuel economy testing procedures. Conduct HFET testing as described in 40 

CFR 1066.840. 
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(c) US06 testing procedures. Conduct US06 testing as described in 40 CFR 1066.830 and 

1066.831.

(d) SC03 testing procedures. Conduct SC03 testing as described in 40 CFR 1066.830 and 

835.

(e) Cold temperature FTP procedures. Conduct cold temperature FTP testing as described 

in 40 CFR part 1066, subpart H.

(f) Testing with alternative fuels. For vehicles designed to operate on an alternative fuel 

in addition to gasoline or diesel fuel, perform FTP and HFET testing as described in 

paragraphs (a) and (b) of this section for each type of fuel on which the vehicle is 

designed to operate. No US06, SC03, or cold temperature FTP testing is required on the 

alternative fuel. 

(g) Testing for vehicles with rechargeable energy storage systems. Test electric vehicles 

and hybrid electric vehicles as described in § 600.116.

(h) Special test procedures. We may allow or require you to use procedures other than 

those specified in this section as described in 40 CFR 1066.10(c). For example, special 

test procedures may be used for advanced technology vehicles, including, but not limited 

to fuel cell vehicles, hybrid electric vehicles using hydraulic energy storage, and vehicles 

equipped with hydrogen internal combustion engines. Additionally, we may conduct fuel 

economy and carbon-related exhaust emission testing using the special test procedures 

approved for a specific vehicle.

§ 600.113-08 and 600.114-08 —[Removed]

214. Remove § 600.113-08 and 600.114-08.

215. Section 600.116-12 is amended as follows:

a. By revising the section heading.

b. By revising paragraph (a)(5).

c. By redesignating paragraphs (b) and (c) as paragraphs (c) and (d), respectively.

d. By adding a new paragraph (b).

e. By revising the redesignated paragraphs (c) introductory text, (c)(1) introductory text, 

(c)(2) introductory text.

f. By revising the redesignated paragraph (c)(5).

g. By adding paragraph (c)(9).

§ 600.116-12 Special procedures related to electric vehicles and hybrid electric 

vehicles.

(a) * * *

(5) We may approve alternate measurement procedures with respect to electric vehicles if 

they are necessary or appropriate for meeting the objectives of this part. For example, we 

may approve the use of an earlier version of SAE J1634 for carryover vehicles, or if you 

show that it is equivalent for your vehicle.

* * * * *

(b) Determine performance values for hybrid electric vehicles that have no plug-in 

capability as specified in §§ 600.210 and 600.311 using the procedures for chargesustaining operation from SAE J1711 (incorporated by reference in § 600.011). We may
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approve alternate measurement procedures with respect to these vehicles if that is 

necessary or appropriate for meeting the objectives of this part. For example, we may

approve alternate Net Energy Change tolerances for charge-sustaining operation as 

described in paragraph (c)(5) of this section.

(c) Determine performance values for hybrid electric vehicles that have plug-in capability

as specified in §§ 600.210 and 600.311 using the procedures of SAE J1711 (incorporated 

by reference in § 600.011), with the following clarifications and modifications:

(1) To determine fuel economy and CREE values to demonstrate compliance with CAFE 

and GHG standards, calculate composite values representing combined operation during 

charge-depleting and charge-sustaining operation using the following utility factors 

except as specified in this paragraph (c):

* * * * *

(2) To determine fuel economy and CO2 emission values for labeling purposes, calculate 

composite values representing combined operation during charge-depleting and chargesustaining operation using the following utility factors except as specified in this 

paragraph (c):

* * * * *

(5) The End-of-Test criterion is based on a 1 percent Net Energy Change as specified in 

Section 3.8 of SAE J1711. We may approve alternate Net Energy Change tolerances as 

specified in Section 3.9.1 or Appendix C of SAE J1711 if the 1 percent threshold is 

insufficient or inappropriate for marking the end of charge-depleting operation. For 

charge-sustaining tests, we may approve the use of alternate Net Energy Change 

tolerances as specified in Appendix C of SAE J1711 to correct final fuel economy values, 

CO2 emissions, and carbon-related exhaust emissions. For charge-sustaining tests, do not 

use alternate Net Energy Change tolerances to correct emissions of criteria pollutants. 

Additionally, if we approve an alternate End-of-Test criterion or Net Energy Change 

tolerances for a specific vehicle, we may use the alternate criterion or tolerances for any 

testing we conduct on that vehicle.

* * * * *

(9) The utility factors described in this paragraph (c) are derived from equations in SAE 

J2841. You may alternatively calculate utility factors directly from the corresponding 

equations in SAE J2841. 

* * * * *

216. A new § 86.117 is added to subpart B to read as follows:

§ 600.117 Interim provisions.

The following provisions apply instead of other provisions specified in this part through 

model year 2019:

(a) Except as specified in paragraph (e) of this section, manufacturers must demonstrate 

compliance with greenhouse gas emission standards and determine fuel economy values 

using gasoline test fuel as specified in 40 CFR 86.113-04(a), regardless of any testing 

with Tier 3 test fuel under paragraph (b) of this section.

(b) Manufacturers may demonstrate that vehicles comply with Tier 3 emission standards 

as specified in 40 CFR part 86, subpart S, during fuel economy measurements using the 
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gasoline test fuel specified in 40 CFR 86.113-04(a), as long as this test fuel is used for all 

the duty cycles specified in 40 CFR part 86, subpart S. If a vehicle fails to meet a Tier 3 

emission standard using the gasoline test fuel specified in 40 CFR 86.113-04(a), the 

manufacturer must retest the vehicle using the Tier 3 test fuel specified in 40 CFR 

1065.710(b) to demonstrate compliance with all applicable emission standards over that 

test cycle. 

(c) If a manufacturer demonstrates compliance with emission standards for criteria 

pollutants over all five test cycles using the Tier 3 test fuel specified in 40 CFR 

1065.710(b), the manufacturer may use the derived five-cycle calculations to demonstrate 

compliance with greenhouse gas emission standards and determine fuel economy values. 

This also applies for fuel economy labeling, as long as the test group meets the criteria 

described in § 600.115. Vehicles tested over the FTP and HFET cycles with the test fuel 

specified in 40 CFR 86.113-04(a) under this paragraph (b) must meet the Tier 3 emission 

standards over those test cycles. 

(d) Manufacturers may perform testing with either gasoline test fuel specified in 40 CFR 

86.113-04(a) or in 40 CFR 1065.710(b) to evaluate whether their vehicles meet the 

criteria for derived 5-cycle testing under 40 CFR 600.115; however, all five tests must 

use test fuel meeting the same specifications. 

(e) For IUVP testing under § 86.1845, manufacturers may demonstrate compliance with 

greenhouse gas emission standards using a test fuel meeting specifications for 

demonstrating compliance with emission standards for criteria pollutants.

Subpart C—[Amended]

§§ 600.206-08, 600.207-08, 600.208 -08, 600.209-08, and 600.210-08 —[Removed]

217. Remove §§ 600.206-08, 600.207-08, 600.208-08, 600.209-08, and 600.210-08.

Subpart D—[Amended]

§§ 600.302-08 and 600.311-08 —[Removed]

218. Remove 600.302-08 and 600.311-08.

219. Section 600.311-12 is amended by revising paragraph (g) to read as follows:

§ 600.311-12 Determination of values for fuel economy labels.

* * * * *

(g) Smog rating. Establish a rating for exhaust emissions other than CO2 based on the 

applicable emission standards for the appropriate model year as shown in Tables 1 

through 3 of this section. For Independent Commercial Importers that import vehicles not 

subject to Tier 2 or Tier 3 emission standards, the vehicle's smog rating is 1. Similarly, if 

a manufacturer certifies vehicles to emission standards that are less stringent than all the 

identified standards for any reason, the vehicle’s smog rating is 1. If EPA or California 

emission standards change in the future, we may revise the emission levels corresponding 

to each rating for future model years as appropriate to reflect the changed standards. If 

this occurs, we would publish the revised ratings as described in § 600.302–12(k), 

allowing sufficient lead time to make the changes; we would also expect to initiate a 

rulemaking to update the smog rating in the regulation.
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Table 1 of § 600.311–12—Criteria for Establishing 

Smog Rating for Model Year 2025 and Later

Rating U.S. EPA Tier 3 Emission 

Standard

California Air Resources Board 

LEV III Emission Standard

1 Bin 160 LEV 160

2 Bin 125 ULEV125

4 Bin 70 ULEV70

5 Bin 50 ULEV50

6 Bin 30 SULEV30

7 Bin 20 SULEV20

10 Bin 0 ZEV

Table 2 of § 600.311–12—Criteria for Establishing 

Smog Rating for Model Years 2018 -2024

Rating U.S. EPA Tier 3 

Emission Standard

U.S EPA Tier 2 

Emission Standard

California Air Resources Board 

LEV III Emission Standard

1 Bin 160 Bin 5 through Bin 8 LEV 160

3 Bin 125 Bin 4 ULEV125

5 Bin 70 Bin 3 ULEV70

6 Bin 50 — ULEV50

7 Bin 30 Bin 2 SULEV30

8 Bin 20 — SULEV20

10 Bin 0 Bin 1 ZEV

Table 3 of § 600.311–12—Criteria for Establishing 

Smog Rating through Model Year 2017

Rating U.S. EPA Tier 2 

Emission Standard

California Air Resources 

Board LEV II 

Emission Standard

California Air Resources 

Board LEV III 

Emission Standard

1 — ULEV & LEV II large 

trucks

2 Bin 8 SULEV II large trucks

3 Bin 7 —

4 Bin 6 LEV II, option 1

5 Bin 5 LEV II LEV160

6 Bin 4 ULEV II ULEV125

7 Bin 3 — ULEV70, ULEV50

8 Bin 2 SULEV II SULEV30

9 — PZEV SULEV20, PZEV

10 Bin 1 ZEV ZEV

* * * * *

Subpart F—[Amended]

§§ 600.507-08, 600.509-08, 600.510-08, and 600.512-08 —[Removed]
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220. Remove §§ 600.507-08, 600.509-08, 600.510-08, and 600.512-08.

Appendix IV and Appendix V to Part 600—[Removed and reserved]

221. Remove and reserve Appendix IV and Appendix V to part 600.

PART 1036—CONTROL OF EMISSIONS FROM NEW AND IN-USE HEAVYDUTY HIGHWAY ENGINES

222. The authority citation for part 1036 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart B—[Amended]

223. Section 1036.115 is amended by adding paragraph (b) to read as follows:

§ 1036.115 Other requirements.

* * * * *

(b) You must design and produce your engines to comply with evaporative emission 

standards as follows:

(1) For complete heavy-duty vehicles you produce, you must certify the vehicles to 

emission standards as specified in 40 CFR 1037.103.

(2) For incomplete heavy-duty vehicles, and for engines used in vehicles you do not 

produce, you do not need to certify your engines to evaporative emission standards or 

otherwise meet those standards. However, vehicle manufacturers certifying their vehicles 

with your engines may depend on you to produce your engines according to their 

specifications. Also, your engines must meet applicable exhaust emission standards in 

the installed configuration.

PART 1037—CONTROL OF EMISSIONS FROM NEW HEAVY-DUTY MOTOR 

VEHICLES 

224. The authority citation for part 1037 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart B – [Amended]

225. Section 1037.101 is amended by revising paragraph (b)(4) and adding paragraph 

(c)(3) to read as follows:

§ 1037.101 Overview of emission standards for heavy-duty vehicles.

* * * * *

(b) * * *

(4) Fuel evaporative emissions. These requirements are described in 40 CFR part 86 and 

§ 1037.103.

(c) * * *

(3) For evaporative and refueling emissions, vehicles are regulated based on the type of 

fuel they use. Vehicles fueled with volatile liquid fuels or gaseous fuels are subject to 

evaporative emission standards. Vehicles up to a certain size that are fueled with 
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gasoline, diesel fuel, ethanol, methanol, or LPG are subject to refueling emission 

standards. 

226. A new § 1037.103 is added to read as follows:

§ 1037.103 Evaporative and refueling emission standards. 

(a) Applicability. Evaporative and refueling emission standards apply to heavy-duty

vehicles as follows: 

(1) Complete and incomplete heavy-duty vehicles at or below 14,000 pounds GVWR 

must meet evaporative and refueling emission standards as specified in 40 CFR part 86, 

subpart S, instead of the requirements specified in this section. 

(2) Heavy-duty vehicles above 14,000 pounds GVWR that run on volatile liquid fuel 

(such as gasoline or ethanol) or gaseous fuel (such as natural gas or LPG) must meet 

evaporative and refueling emission standards as specified in this section. 

(b) Emission standards. The evaporative and refueling emission standards and 

measurement procedures specified in 40 CFR 86.1813 apply for vehicles above 14,000 

pounds GVWR, except as described in this section. The evaporative emission standards 

phase in over model years 2018 through 2022, with provisions allowing for voluntary

compliance with the standards as early as model year 2015. Count vehicles subject to 

standards under this section the same as heavy-duty vehicles at or below 14,000 pounds 

GVWR to comply with the phase-in requirements specified in 40 CFR 86.1813. These 

vehicles may generate and use emission credits as described in 40 CFR part 86, subpart 

S, but only for vehicles that are tested for certification instead of relying on the provisions 

of paragraph (c) of this section. The following provisions apply instead of what is 

specified in 40 CFR 86.1813:

(1) The refueling standards in 40 CFR 86.1813(b) apply to complete vehicles starting in 

model year 2022; they are optional for incomplete vehicles.

(2) The leak standard in 40 CFR 86.1813(a)(4) does not apply.

(3) The FEL cap relative to the diurnal plus hot soak standard for low-altitude testing is 

1.9 grams per test.

(4) The diurnal plus hot soak standard for high-altitude testing is 2.3 grams per test.

(5) Testing does not require measurement of exhaust emissions. Disregard references in 

subpart B of this part to procedures, equipment specifications, and recordkeeping related 

to measuring exhaust emissions. All references to the exhaust test under 40 CFR part 86, 

subpart B, are considered the “dynamometer run” as part of the evaporative testing 

sequence under this subpart.

(6) Vehicles not yet subject to the Tier 3 standards in 40 CFR 86.1813 must meet 

evaporative emission standards as specified in §§ 86.008-10(b) and 86.007-11(b)(3) and 

(4).

(c) Compliance demonstration. You may provide a statement in the application for 

certification that vehicles above 14,000 pounds GVWR comply with evaporative and 

refueling emission standards instead of submitting test data if you include an engineering 

analysis describing how vehicles include design parameters, equipment, operating 

controls, or other elements of design that adequately demonstrate that vehicles comply

with the standards. We would expect emission control components and systems to 
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exhibit a comparable degree of control relative to vehicles that comply based on testing. 

For example, vehicles that comply under this paragraph (c) should rely on comparable 

material specifications to limit fuel permeation, and components should be sized and 

calibrated to correspond with the appropriate fuel capacities, fuel flow rates, purge 

strategies, and other vehicle operating characteristics. You may alternatively show that 

design parameters are comparable to those for vehicles at or below 14,000 pounds 

GVWR certified under 40 CFR part 86, subpart S.

(d) CNG refueling requirement. Compressed natural gas vehicles must meet the 

requirements for fueling connection devices as specified in 40 CFR 86.1813-17(f)(1). 

Vehicles meeting these requirements are deemed to comply with evaporative and 

refueling emission standards.

(e) Incomplete vehicles. If you sell incomplete vehicles, you must identify the maximum 

fuel tank capacity for which you designed the vehicle’s evaporative emission control 

system. 

(f) Useful life. Your vehicles must meet the evaporative emission standards of this 

section throughout their useful life, expressed in service miles or calendar years, 

whichever comes first. The useful life values for the standards of this section are those 

that apply for criteria pollutants under 40 CFR part 86.

(g) Auxiliary engines and separate fuel systems. The provisions of this paragraph (g) 

apply for vehicles with auxiliary engines. This includes any engines installed in the final 

vehicle configuration that contribute no motive power through the vehicle’s transmission. 

(1) Auxiliary engines and associated fuel-system components must be installed when 

testing complete vehicles. If the auxiliary engine draws fuel from a separate fuel tank, 

you must fill the extra fuel tank before the start of diurnal testing as described for the 

vehicle’s main fuel tank. Use good engineering judgment to ensure that any nonmetal 

portions of the fuel system related to the auxiliary engine have reached stabilized levels 

of permeation emissions. The auxiliary engine must not operate during the running loss 

test or any other portion of testing under this section.

(2) For testing with incomplete vehicles, you may omit installation of auxiliary engines 

and associated fuel-system components as long as those components installed in the final 

configuration are certified to meet the applicable emission standards for Small SI

equipment described in 40 CFR 1054.112 or for Large SI engines in 40 CFR 1048.105. 

For any fuel-system components that you do not install, your installation instructions 

must describe this certification requirement.

227. Section 1037.104 is amended by adding paragraph (h)(2) to read as follows:

§ 1037.104 Exhaust emission standards for CO2, CH4, and N2O for heavy-duty 

vehicles at or below 14,000 pounds GVWR.

* * * * *

(h) * * *

(2) The evaporative and refueling emission standards in § 1037.103.

* * * * *

Subpart C—[Amended]
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228. Section 1037.230 is amended by adding paragraph (e) to read as follows:

§ 1037.230 Vehicle families, sub-families, and configurations.

* * * * *

(e) Divide your vehicles that are subject to evaporative emission standards into groups of 

vehicles with similar physical features expected to affect evaporative emissions. Group 

vehicles in the same evaporative emission family if they are the same in all the following 

aspects, unless we approve a better way of grouping vehicles into families that have 

similar emission control characteristics:

(1) Method of vapor storage, including the number of vapor storage devices, the working 

material, and the total working capacity of vapor storage (as determined under 40 CFR 

86.132-96(h)(1)(iv)). You may consider the working capacity to be the same if the 

values differ by 20 grams or less.

(2) Method of purging stored vapors.

(3) Material for liquid and vapor fuel lines.

* * * * *

229. A new § 1037.243 is added to subpart C to read as follows:

§ 1037.243 Demonstrating compliance with evaporative emission standards.

(a) For purposes of certification, your vehicle family is considered in compliance with the 

evaporative emission standards in subpart B of this part if you prepare an engineering 

analysis showing that your vehicles in the family will comply with applicable standards 

throughout the useful life, and there are no test results from an emission-data vehicle 

representing the family that exceed an emission standard.

(b) Your evaporative emission family is deemed not to comply if your engineering 

analysis is not adequate to show that all the vehicles in the family will comply with 

applicable emission standards throughout the useful life, or if a test result from an 

emission-data vehicle representing the family exceeds an emission standard.

(c) To compare emission levels with emission standards, apply deterioration factors to the 

measured emission levels. Establish an additive deterioration factor based on an 

engineering analysis that takes into account the expected aging from in-use vehicles. 

(d) Apply the deterioration factor to the official emission result, as described in paragraph 

(c) of this section, then round the adjusted figure to the same number of decimal places as 

the emission standard. Compare the rounded emission levels to the emission standard for 

each emission-data vehicle. 

(e) Your analysis to demonstrate compliance with emission standards must take into 

account your design strategy for vehicles that require testing. Specifically, vehicles 

above 14,000 pounds GVWR are presumed to need the same technologies that are 

required for heavy-duty vehicles at or below 14,000 pounds GVWR. Similarly, your 

analysis to establish a deterioration factor must take into account your testing to establish 

deterioration factors for smaller vehicles.

Subpart F—[Amended]

230. Section 1037.501 is amended by adding paragraph (a) to read as follows:
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§ 1037.501 General testing and modeling provisions.

* * * * *

(a) Use the equipment and procedures specified in 40 CFR part 1066 § 10to determine 

whether vehicles meet the evaporative and refueling emission standards specified in 

§ 1037.103. 

* * * * *

PART 1039—CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD 

COMPRESSION-IGNITION ENGINES

231. The authority citation for part 1039 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart F—[Amended]

232. Section 1039.505 is revised to read as follows:

§ 1039.505 How do I test engines using steady-state duty cycles, including rampedmodal testing?

This section describes how to test engines under steady-state conditions. In some cases, 

we allow you to choose the appropriate steady-state duty cycle for an engine; you may

also choose between discrete-mode and ramped-modal testing. In all cases, you must use 

the duty cycle you select in your application for certification for all testing you perform 

for that engine family. If we test your engines to confirm that they meet emission 

standards, we will use the duty cycle you select for your own testing. If you submit 

certification test data using more than one duty cycle, any of the selected duty cycles may

be used for any subsequent testing. We may also perform other testing as allowed by the 

Clean Air Act.

(a) You may perform steady-state testing with either discrete-mode or ramped-modal 

cycles as described in 40 CFR part 1065.

(b) Measure emissions by testing the engine on a dynamometer with one of the following 

duty cycles to determine whether it meets the steady-state emission standards in § 

1039.101(b):

(1) Use the 5-mode duty cycle or the corresponding ramped-modal cycle described in 

paragraph (a) of Appendix II of this part for constant-speed engines. Note that these 

cycles do not apply to all engines used in constant-speed applications, as described in § 

1039.801.

(2) Use the 6-mode duty cycle or the corresponding ramped-modal cycle described in 

paragraph (b) of Appendix II of this part for variable-speed engines below 19 kW. You 

may instead use the 8-mode duty cycle or the corresponding ramped-modal cycle 

described in appendix IV of this part if some engines from your engine family will be 

used in applications that do not involve governing to maintain engine operation around 

rated speed.

(3) Use the 8-mode duty cycle or the corresponding ramped-modal cycle described in 

paragraph (c) of Appendix II of this part for variable-speed engines at or above 19 kW.

(c) For constant-speed engines whose design prevents full-load operation for extended 

periods, you may ask for approval under 40 CFR 1065.10(c) to replace full-load 
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operation with the maximum load for which the engine is designed to operate for 

extended periods.

(d) To allow non-motoring dynamometers on cycles with idle, you may omit additional 

points from the duty-cycle regression as follows:

(1) For variable-speed engines with low-speed governors, you may omit speed, torque, 

and power points from the duty-cycle regression statistics if the following are met:

(i) The engine operator demand is at its minimum.

(ii) The dynamometer demand is at its minimum.

(iii) It is an idle point fnref = 0 % (idle) and Tref = 0 % (idle).

(iv) Tref < T ≤ 5 % · Tmaxmapped.

(2) For variable-speed engines without low-speed governors, you may omit torque and 

power points from the duty-cycle regression statistics if the following are met:

(i) The dynamometer demand is at its minimum.

(ii) It is an idle point fnref = 0 % (idle) and Tref = 0 % (idle).

(iii) fnref − (2 % · fntest) < fn < fnref + (2 % · fntest).

(iv) Tref < T ≤ 5 % · Tmaxmapped.

§ 1039.510—[Amended]

233. Section 1039.510 is amended by removing paragraph (c).

Part 1042— Control of Emissions from New and In-use Marine Compressionignition Engines and Vessels

234. The authority citation for part 1042 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart F—[Amended]

235. Section 1042.505 is revised to read as follows:

§ 1042.505 Testing engines using discrete-mode or ramped-modal duty cycles.

This section describes how to test engines under steady-state conditions. In some cases, 

we allow you to choose the appropriate steady-state duty cycle for an engine; you may

also choose between discrete-mode and ramped-modal testing. In all cases, you must use 

the duty cycle you select in your application for certification for all testing you perform 

for that engine family. If we test your engines to confirm that they meet emission 

standards, we will use the duty cycles you select for your own testing. If you submit 

certification test data using more than one duty cycle, any of the selected duty cycles may

be used for any subsequent testing. We may also perform other testing as allowed by the 

Clean Air Act.

(a) You may perform steady-state testing with either discrete-mode or ramped-modal 

cycles as described in 40 CFR part 1065.

(b) Measure emissions by testing the engine on a dynamometer with one of the following 

duty cycles (as specified) to determine whether it meets the emission standards in §§ 

1042.101 or 1042.104:

(1) General cycle. Use the 4-mode duty cycle or the corresponding ramped-modal cycle 

described in paragraph (a) of Appendix II of this part for commercial propulsion marine 
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engines that are used with (or intended to be used with) fixed-pitch propellers, propellerlaw auxiliary engines, and any other engines for which the other duty cycles of this 

section do not apply. Use this duty cycle also for commercial variable-speed propulsion 

marine engines that are used with (or intended to be used with) controllable-pitch 

propellers or with electrically coupled propellers, unless these engines are not intended 

for sustained operation (e.g., for at least 30 minutes) at all four modes when installed in 

the vessel.

(2) Recreational marine engines. Except as specified in paragraph (b)(3) of this section, 

use the 5-mode duty cycle or the corresponding ramped-modal cycle described in 

paragraph (b) of Appendix II of this part for recreational marine engines with maximum 

engine power at or above 37 kW.

(3) Controllable-pitch and electrically coupled propellers. Use the 4-mode duty cycle or 

the corresponding ramped-modal cycle described in paragraph (c) of Appendix II of this 

part for constant-speed propulsion marine engines that are used with (or intended to be 

used with) controllable-pitch propellers or with electrically coupled propellers. Use this 

duty cycle also for variable-speed propulsion marine engines that are used with (or 

intended to be used with) controllable-pitch propellers or with electrically coupled 

propellers if the duty cycles in paragraph (b)(1) and (b)(2) of this section do not apply.

(4) Constant-speed auxiliary engines. Use the 5-mode duty cycle or the corresponding 

ramped-modal cycle described in 40 CFR part 1039, Appendix II, paragraph (a) for 

constant-speed auxiliary engines.

(5) Variable-speed auxiliary engines. (i) Use the duty cycle specified in paragraph (b)(1) 

of this section for propeller-law auxiliary engines.

(ii) Use the 6-mode duty cycle or the corresponding ramped-modal cycle described in 40 

CFR part 1039, Appendix II, paragraph (b) for variable-speed auxiliary engines with 

maximum engine power below 19 kW that are not propeller-law engines.

(iii) Use the 8-mode duty cycle or the corresponding ramped-modal cycle described in 40 

CFR part 1039, Appendix III, paragraph (c) for variable-speed auxiliary engines with 

maximum engine power at or above 19 kW that are not propeller-law engines.

(c) For constant-speed engines whose design prevents full-load operation for extended 

periods, you may ask for approval under 40 CFR 1065.10(c) to replace full-load 

operation with the maximum load for which the engine is designed to operate for 

extended periods.

Part 1048— Control of Emissions from New, Large Nonroad Spark-ignition 

Engines

236. The authority citation for part 1048 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart F—[Amended]

237. Section 1048.505 is amended by revising the introductory text and paragraphs 

(a) and (c) and removing paragraphs (d) through (g) to read as follows:

§ 1048.505 How do I test engines using steady-state duty cycles, including rampedmodal testing?
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This section describes how to test engines under steady-state conditions. In some cases, 

we allow you to choose the appropriate steady-state duty cycle for an engine; you may

also choose between discrete-mode and ramped-modal testing. In all cases, you must use 

the duty cycle you select in your application for certification for all testing you perform

for that engine family. If we test your engines to confirm that they meet emission 

standards, we will use the duty cycles you select for your own testing. If you submit 

certification test data using more than one duty cycle, any of the selected duty cycles may

be used for any subsequent testing. We may also perform other testing as allowed by the 

Clean Air Act.

(a) You may perform steady-state testing with either discrete-mode or ramped-modal 

cycles described in 40 CFR part 1065.

* * * * *

(c) For full-load operating modes, operate the engine at wide-open throttle.

Part 1054— Control of Emissions from New, Small Nonroad Spark-ignition Engines 

and Equipment

238. The authority citation for part 1054 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart F—[Amended]

239. Section 1054.505 is amended by revising paragraph (a) and removing paragraph 

(e) to read as follows:

§ 1054.505 How do I test engines?

(a) This section describes how to test engines under steady-state conditions. For handheld 

engines you must perform tests with discrete-mode sampling. For nonhandheld engines 

we allow you to perform tests with either discrete-mode or ramped-modal testing 

methods, as described in 40 CFR part 1065. You must use the same modal testing method 

for certification and all other testing you perform for an engine family. If we test your 

engines to confirm that they meet emission standards, we will use the modal testing 

method you select for your own testing. If you submit certification test data collected 

with both discrete-mode and ramped-modal testing (either in your original application or 

in an amendment to your application), either method may be used for subsequent testing. 

We may also perform other testing as allowed by the Clean Air Act. Conduct duty-cycle 

testing as follows:

(1) For discrete-mode testing, sample emissions separately for each mode, then calculate 

an average emission level for the whole cycle using the weighting factors specified for 

each mode. Control engine speed as specified in this section. Use one of the following 

methods for confirming torque values for nonhandheld engines:

(i) Calculate torque-related cycle statistics and compare with the established criteria as 

specified in 40 CFR 1065.514 to confirm that the test is valid.

(ii) Evaluate each mode separately to validate the duty cycle. All torque feedback values 

recorded during non-idle sampling periods must be within ±2 percent of the reference 

value or within ±0.27 N·m of the reference value, whichever is greater. Also, the mean 

torque value during non-idle sampling periods must be within ±1 percent of the reference 
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value or ±0.12 N·m of the reference value, whichever is greater. Control torque during 

idle as specified in paragraph (c) of this section.

(2) Unless we specify otherwise, you may simulate the governor for ramped-modal 

testing consistent with good engineering judgment.

* * * * *

PART 1065—ENGINE-TESTING PROCEDURES

240. The authority citation for part 1065 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart A—[Amended]

241. Section 1065.1 is amended by revising paragraph (h) to read as follows:

§ 1065.1 Applicability.

* * * * *

(h) This part describes procedures and specifications for measuring an engine’s exhaust 

emissions. While the measurements are geared toward engine-based measurements (in 

units of g/kW·hr), many of these provisions apply equally to vehicle-based measurements 

(in units of g/mile or g/kilometer). 40 CFR part 1066 describes the analogous procedures 

for vehicle-based emission measurements, and in many cases states that specific 

provisions of this part 1065 also apply for those vehicle-based measurements. Where 

material from this part 1065 applies for vehicle-based measurements under 40 CFR part 

1066, it is sometimes necessary to include parenthetical statements in this part 1065 to 

properly cite secondary references that are different for vehicle-based testing. See 40 

CFR part 1066 and the standard-setting part for additional information.

242. Section 1065.2 is amended by revising paragraphs (d) and (e) to read as follows:

§ 1065.2 Submitting information to EPA under this part.

* * * * *

(d) We may require an authorized representative of your company to approve and sign 

the submission, and to certify that all the information submitted is accurate and complete. 

This includes everyone who submits information, including manufacturers and others.

(e) See 40 CFR 1068.10 for provisions related to confidential information. Note however 

that under 40 CFR 2.301, emission data are generally not eligible for confidential 

treatment.

* * * * *

243. Section 1065.10 is amended by revising paragraphs (a), (c)(7) introductory text, 

and (d) to read as follows:

§ 1065.10 Other procedures.

(a) Your testing. The procedures in this part apply for all testing you do to show 

compliance with emission standards, with certain exceptions noted in this section. In 

some other sections in this part, we allow you to use other procedures (such as less 
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precise or less accurate procedures) if they do not affect your ability to show that your 

engines comply with the applicable emission standards. This generally requires emission 

levels to be far enough below the applicable emission standards so that any errors caused 

by greater imprecision or inaccuracy do not affect your ability to state unconditionally

that the engines meet all applicable emission standards.

* * * * *

(c) * * *

(7) You may request to use alternate procedures that are equivalent to the specified 

procedures, or procedures that are more accurate or more precise than the specified 

procedures. We may perform tests with your engines using either the approved alternate 

procedures or the specified procedures. The following provisions apply to requests for 

alternate procedures:

* * * * *

(d) Advance approval. If we require you to request approval to use other procedures 

under paragraph (c) of this section, you may not use them until we approve your request.

244. Section 1065.12 is amended by revising paragraphs (a), (d) introductory text, and 

(e) introductory text to read as follows:

§ 1065.12 Approval of alternate procedures.

(a) To get approval for an alternate procedure under § 1065.10(c), send the Designated 

Compliance Officer an initial written request describing the alternate procedure and why 

you believe it is equivalent to the specified procedure. Anyone may request alternate 

procedure approval. This means that an individual engine manufacturer may request to 

use an alternate procedure. This also means that an instrument manufacturer may request 

to have an instrument, equipment, or procedure approved as an alternate procedure to 

those specified in this part. We may approve your request based on this information 

alone, whether or not it includes all the information specified in this section. Where we 

determine that your original submission does not include enough information for us to 

determine that the alternate procedure is equivalent to the specified procedure, we may

ask you to submit supplemental information showing that your alternate procedure is 

consistently and reliably at least as accurate and repeatable as the specified procedure.

* * * * *

(d) If we do not approve your proposed alternate procedure based on the information in 

your initial request, we may ask you to send additional information to fully evaluate your 

request. While we consider the information specified in this paragraph (d) and the 

statistical criteria of paragraph (e) of this section to be sufficient to demonstrate 

equivalence, it may not be necessary to include all the information or meet the specified 

statistical criteria. For example, systems that do not meet the statistical criteria in 

paragraph (e) of this section because they have a small bias toward high emission results 

could be approved since they would not adversely affect your ability to demonstrate 

compliance with applicable standards.

* * * * *

(e) Absent any other directions from us, use a t-test and an F-test calculated according to 

§ 1065.602 to evaluate whether your proposed alternate procedure is equivalent to the 
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specified procedure. We may give you specific directions regarding methods for 

statistical analysis, or we may approve other methods that you propose. Such alternate 

methods may be more or less stringent than those specified in this paragraph (e). In 

determining the appropriate statistical criteria, we will consider the repeatability of 

measurements made with the reference procedure. For example, less stringent statistical 

criteria may be appropriate for measuring emission levels being so low that they

adversely affect the repeatability of reference measurements. We recommend that you 

consult a statistician if you are unfamiliar with these statistical tests. Perform the tests as 

follows:

* * * * *

245. Section 1065.15 is amended by revising paragraphs (a), (b), and (c)(2)(ii) to read 

as follows:

§ 1065.15 Overview of procedures for laboratory and field testing.

* * * * *

(a) In the standard-setting part, we set brake-specific emission standards in g/(kW·hr) (or 

g/(hp·hr)), for the following constituents:

(1) Total oxides of nitrogen, NOx.

(2) Hydrocarbons, HC, which may be expressed in the following ways:

(i) Total hydrocarbons, THC.

(ii) Nonmethane hydrocarbons, NMHC, which results from subtracting methane, CH4, 

from THC.

(iii) Total hydrocarbon-equivalent, THCE, which results from adjusting THC 

mathematically to be equivalent on a carbon-mass basis.

(iv) Nonmethane hydrocarbon-equivalent, NMHCE, which results from adjusting NMHC 

mathematically to be equivalent on a carbon-mass basis.

(3) Particulate matter, PM.

(4) Carbon monoxide, CO.

(5) Carbon dioxide, CO2.

(6) Methane, CH4.

(7) Nitrous oxide, N2O.

(b) Note that some engines are not subject to standards for all the emission constituents 

identified in paragraph (a) of this section. Note also that the standard-setting part may

include standards for pollutants not listed in paragraph (a) of this section.

(c) * * *

(2) * * *

(ii) Batch sampling. In batch sampling, continuously extract and store a sample of raw or 

dilute exhaust for later measurement. Extract a sample proportional to the raw or dilute 

exhaust flow rate. You may extract and store a proportional sample of exhaust in an 

appropriate container, such as a bag, and then measure NOx, HC, CO, CO2, CH4, N2O, 

and CH2O concentrations in the container after the test interval. You may deposit PM 

from proportionally extracted exhaust onto an appropriate substrate, such as a filter. In 

this case, divide the PM by the amount of filtered exhaust to calculate the PM 

concentration. Multiply batch sampled concentrations by the total (raw or dilute) flow 
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from which it was extracted during the test interval. This product is the total mass of the 

emitted constituent.

* * * * *

246. Section 1065.20 is amended by revising paragraphs (a)(3), (b) introductory text, 

(c), (f)(1) and (g) to read as follows:

§ 1065.20 Units of measure and overview of calculations.

(a) * * *

(3) We generally designate temperatures in units of degrees Celsius (°C) unless a 

calculation requires an absolute temperature. In that case, we designate temperatures in 

units of Kelvin (K). For conversion purposes throughout this part, 0 °C equals 273.15 K. 

Unless specified otherwise, always use absolute temperature values for multiplying or 

dividing by temperature.

(b) Concentrations. This part does not rely on amounts expressed in parts per million. 

Rather, we express such amounts in the following SI units:

* * * * *

(c) Absolute pressure. Measure absolute pressure directly or calculate it as the sum of 

atmospheric pressure plus a differential pressure that is referenced to atmospheric 

pressure. Always use absolute pressure values for multiplying or dividing by pressure.

* * * * *

(f) * * *

(1) Whenever we specify a range by a single value and corresponding limit values above 

and below that value (such as X ±Y), target the associated control point to that single 

value (X). Examples of this type of range include “±10 % of maximum pressure”, or 

“(30 ±10) kPa”. In these examples, you would target the maximum pressure or 30 kPa, 

respectively.

* * * * *

(g) Scaling of specifications with respect to an applicable standard. Because this part 

1065 is applicable to a wide range of engines and emission standards, some of the 

specifications in this part are scaled with respect to an engine’s applicable standard or 

maximum power. This ensures that the specification will be adequate to determine 

compliance, but not overly burdensome by requiring unnecessarily high-precision 

equipment. Many of these specifications are given with respect to a “flow-weighted 

mean” that is expected at the standard or during testing. Flow-weighted mean is the 

mean of a quantity after it is weighted proportional to a corresponding flow rate. For 

example, if a gas concentration is measured continuously from the raw exhaust of an 

engine, its flow-weighted mean concentration is the sum of the products (dry-to-wet 

corrected, if applicable) of each recorded concentration times its respective exhaust flow 

rate, divided by the sum of the recorded flow rates. As another example, the bag 

concentration from a CVS system is the same as the flow-weighted mean concentration, 

because the CVS system itself flow-weights the bag concentration. Refer to § 1065.602 

for information needed to estimate and calculate flow-weighted means. Wherever a 

specification is scaled to a value based upon an applicable standard, interpret the standard 
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to be the family emission limit if the engine is certified under an emission credit program 

in the standard-setting part.

247. Section 1065.25 is revised to read as follows:

§ 1065.25 Recordkeeping.

(a) The procedures in this part include various requirements to record data or other 

information. Refer to the standard-setting part and § 1065.695 regarding specific 

recordkeeping requirements.

(b) You must promptly send us organized, written records in English if we ask for them. 

We may review them at any time.

(c) We may waive specific reporting or recordkeeping requirements we determine to be 

unnecessary for the purposes of this part and the standard-setting part. Note that while 

we will generally keep the records required by this part, we are not obligated to keep 

records we determine to be unnecessary for us to keep. For example, while we require 

you to keep records for invalid tests so that we may verify that your invalidation was 

appropriate, it is not necessary for us to keep records for our own invalid tests. 

Subpart B—[Amended]

248. Section 1065.130 is amended by revising paragraphs (a) and (c)(6) to read as 

follows:

§ 1065.130 Engine exhaust.

(a) General. Use the exhaust system installed with the engine or one that represents a 

typical in-use configuration. This includes any applicable aftertreatment devices. We 

refer to exhaust piping as an exhaust stack; this is equivalent to a tailpipe for vehicle 

configurations.

* * * * *

(c) * * *

(6) We recommend that you connect multiple exhaust stacks from a single engine into 

one stack upstream of any emission sampling. For raw or dilute partial-flow emission 

sampling, to ensure mixing of the multiple exhaust streams before emission sampling, we 

recommend a minimum Reynolds number, Re#, of 4000 for the combined exhaust stream, 

where Re#is based on the inside diameter of the combined flow at the first sampling 

point. You may configure the exhaust system with turbulence generators, such as orifice 

plates or fins, to achieve good mixing; inclusion of turbulence generators may be required 

for Re#less than 4000 to ensure good mixing. Re#is defined in § 1065.640. For dilute 

full-flow (CVS) emission sampling, you may configure the exhaust system without 

regard to mixing in the laboratory section of the raw exhaust. For example you may size 

the laboratory section to reduce its pressure drop even if the Re#in the laboratory section 

of the raw exhaust is less than 4000.

* * * * *

249. Section 1065.140 is revised to read as follows:

§ 1065.140 Dilution for gaseous and PM constituents.
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(a) General. You may dilute exhaust with ambient air, purified air, or nitrogen. 

References in this part to “dilution air” may include any of these. For gaseous emission 

measurement, the dilution air must be at least 15 °C. Note that the composition of the 

dilution air affects some gaseous emission measurement instruments’ response to 

emissions. We recommend diluting exhaust at a location as close as possible to the 

location where ambient air dilution would occur in use. Dilution may occur in a single 

stage or in multiple stages. For dilution in multiple stages, the first stage is considered 

primary dilution and later stages are considered secondary dilution.

(b) Dilution-air conditions and background concentrations. Before dilution air is mixed 

with exhaust, you may precondition it by increasing or decreasing its temperature or 

humidity. You may also remove constituents to reduce their background concentrations. 

The following provisions apply to removing constituents or accounting for background 

concentrations:

(1) You may measure constituent concentrations in the dilution air and compensate for 

background effects on test results. See § 1065.650 for calculations that compensate for 

background concentrations (40 CFR 1066.610 for vehicle testing).

(2) Measure these background concentrations the same way you measure diluted exhaust 

constituents, or measure them in a way that does not affect your ability to demonstrate 

compliance with the applicable standards. For example, you may use the following 

simplifications for background sampling:

(i) You may disregard any proportional sampling requirements.

(ii) You may use unheated gaseous sampling systems.

(iii) You may use unheated PM sampling systems.

(iv) You may use continuous sampling if you use batch sampling for diluted emissions.

(v) You may use batch sampling if you use continuous sampling for diluted emissions.

(3) For removing background PM, we recommend that you filter all dilution air, 

including primary full-flow dilution air, with high-efficiency particulate air (HEPA) 

filters that have an initial minimum collection efficiency specification of 99.97 % (see § 

1065.1001 for procedures related to HEPA-filtration efficiencies). Ensure that HEPA 

filters are installed properly so that background PM does not leak past the HEPA filters. 

If you choose to correct for background PM without using HEPA filtration, demonstrate 

that the background PM in the dilution air contributes less than 50 % to the net PM 

collected on the sample filter. You may correct net PM without restriction if you use 

HEPA filtration.

(c) Full-flow dilution; constant-volume sampling (CVS). You may dilute the full flow of 

raw exhaust in a dilution tunnel that maintains a nominally constant volume flow rate, 

molar flow rate or mass flow rate of diluted exhaust, as follows:

(1) Construction. Use a tunnel with inside surfaces of 300 series stainless steel. 

Electrically ground the entire dilution tunnel. We recommend a thin-walled and insulated 

dilution tunnel to minimize temperature differences between the wall and the exhaust 

gases. You may not use any flexible tubing in the dilution tunnel upstream of the PM 

sample probe. You may use nonconductive flexible tubing downstream of the PM 

sample probe and upstream of the CVS flow meter; use good engineering judgment to 
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select a tubing material that is not prone to leaks, and configure the tubing to ensure 

smooth flow at the CVS flow meter. 

(2) Pressure control. Maintain static pressure at the location where raw exhaust is 

introduced into the tunnel within ±1.2 kPa of atmospheric pressure. You may use a 

booster blower to control this pressure. If you test using more careful pressure control 

and you show by engineering analysis or by test data that you require this level of control 

to demonstrate compliance at the applicable standards, we will maintain the same level of 

static pressure control when we test.

(3) Mixing. Introduce raw exhaust into the tunnel by directing it downstream along the 

centerline of the tunnel. If you dilute directly from the exhaust stack, the end of the 

exhaust stack is considered to be the start of the dilution tunnel. You may introduce a 

fraction of dilution air radially from the tunnel’s inner surface to minimize exhaust 

interaction with the tunnel walls. You may configure the system with turbulence 

generators such as orifice plates or fins to achieve good mixing. We recommend a 

minimum Reynolds number, Re#, of 4000 for the diluted exhaust stream, where Re#is 

based on the inside diameter of the dilution tunnel. Re#is defined in § 1065.640.

(4) Flow measurement preconditioning. You may condition the diluted exhaust before 

measuring its flow rate, as long as this conditioning takes place downstream of any

heated HC or PM sample probes, as follows:

(i) You may use flow straighteners, pulsation dampeners, or both of these.

(ii) You may use a filter.

(iii) You may use a heat exchanger to control the temperature upstream of any flow 

meter, but you must take steps to prevent aqueous condensation as described in paragraph 

(c)(6) of this section.

(5) Flow measurement. Section 1065.240 describes measurement instruments for diluted 

exhaust flow.

(6) Aqueous condensation. This paragraph (c)(6) describes how you must address 

aqueous condensation in the CVS. As described below, you may meet these 

requirements by preventing or limiting aqueous condensation in the CVS from the 

exhaust inlet to the last emission sample probe. See that paragraph for provisions related 

to the CVS between the last emission sample probe and the CVS flow meter. You may

heat and/or insulate the dilution tunnel walls, as well as the bulk stream tubing 

downstream of the tunnel to prevent or limit aqueous condensation. Where we allow 

aqueous condensation to occur, use good engineering judgment to ensure that the 

condensation does not affect your ability to demonstrate that your engines comply with 

the applicable standards (see § 1065.10(a)).

(i) Preventing aqueous condensation. To prevent condensation, you must keep the 

temperature of internal surfaces, excluding any sample probes, above the dew point of the 

dilute exhaust passing through the CVS tunnel. Use good engineering judgment to 

monitor temperatures in the CVS. For the purposes of this paragraph (c)(6), assume that 

aqueous condensation is pure water condensate only, even though the definition of 

“aqueous condensation” in § 1065.1001 includes condensation of any constituents that 

contain water. No specific verification check is required under this paragraph (c)(6)(i), 

but we may ask you to show how you comply with this requirement. You may use 
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engineering analysis, CVS tunnel design, alarm systems, measurements of wall 

temperatures, and calculation of water dew point to demonstrate compliance with this 

requirement. For optional CVS heat exchangers, you may use the lowest water 

temperature at the inlet(s) and outlet(s) to determine the minimum internal surface 

temperature. 

(ii) Limiting aqueous condensation. This paragraph (c)(6)(ii) specifies limits of 

allowable condensation and requires you to verify that the amount of condensation that 

occurs during each test interval does not exceed the specified limits.

(A) Use chemical balance equations in § 1065.655 to calculate the mole fraction of water 

in the dilute exhaust continuously during testing. Alternatively, you may continuously

measure the mole fraction of water in the dilute exhaust prior to any condensation during 

testing. Use good engineering judgment to select, calibrate and verify water 

analyzers/detectors. The linearity verification requirements of § 1065.307 do not apply to 

water analyzers/detectors used to correct for the water content in exhaust samples.

(B) Use good engineering judgment to select and monitor locations on the CVS tunnel 

walls prior to the last emission sample probe. If you are also verifying limited 

condensation from the last emission sample probe to the CVS flow meter, use good 

engineering judgment to select and monitor locations on the CVS tunnel walls, optional 

CVS heat exchanger, and CVS flow meter. For optional CVS heat exchangers, you may 

use the lowest water temperature at the inlet(s) and outlet(s) to determine the minimum 

internal surface temperature. Identify the minimum surface temperature on a continuous 

basis. 

(C) Identify the maximum potential mole fraction of dilute exhaust lost on a continuous 

basis during the entire test interval. This value must be less than or equal to 0.02. 

Calculate on a continuous basis the mole fraction of water that would be in equilibrium 

with liquid water at the measured minimum surface temperature. Subtract this mole 

fraction from the mole fraction of water that would be in the exhaust without 

condensation (either measured or from the chemical balance), and set any negative values 

to zero. This difference is the potential mole fraction of the dilute exhaust that would be 

lost due to water condensation on a continuous basis.

(D) Integrate the product of the molar flow rate of the dilute exhaust and the potential 

mole fraction of dilute exhaust lost, and divide by the totalized dilute exhaust molar flow 

over the test interval. This is the potential mole fraction of the dilute exhaust that would 

be lost due to water condensation over the entire test interval. Note that this assumes no 

re-evaporation. This value must be less than or equal to 0.005.

(7) Flow compensation. Maintain nominally constant molar, volumetric or mass flow of 

diluted exhaust. You may maintain nominally constant flow by either maintaining the 

temperature and pressure at the flow meter or by directly controlling the flow of diluted 

exhaust. You may also directly control the flow of proportional samplers to maintain 

proportional sampling. For an individual test, verify proportional sampling as described 

in § 1065.545.

(d) Partial-flow dilution (PFD). You may dilute a partial flow of raw or previously

diluted exhaust before measuring emissions. Section 1065.240 describes PFD-related 

flow measurement instruments. PFD may consist of constant or varying dilution ratios as 
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described in paragraphs (d)(2) and (3) of this section. An example of a constant dilution 

ratio PFD is a “secondary dilution PM” measurement system.

(1) Applicability. (i) You may use PFD to extract a proportional raw exhaust sample for 

any batch or continuous PM emission sampling over any transient duty cycle, any steadystate duty cycle, or any ramped-modal cycle.

(ii) You may use PFD to extract a proportional raw exhaust sample for any batch or 

continuous gaseous emission sampling over any transient duty cycle, any steady-state 

duty cycle, or any ramped-modal cycle.

(iii) You may use PFD to extract a proportional raw exhaust sample for any batch or 

continuous field-testing.

(iv)You may use PFD to extract a proportional diluted exhaust sample from a CVS for 

any batch or continuous emission sampling.

(v) You may use PFD to extract a constant raw or diluted exhaust sample for any

continuous emission sampling.

(vi) You may use PFD to extract a constant raw or diluted exhaust sample for any steadystate emission sampling.

(2) Constant dilution-ratio PFD. Do one of the following for constant dilution-ratio PFD:

(i) Dilute an already proportional flow. For example, you may do this as a way of 

performing secondary dilution from a CVS tunnel to achieve overall dilution ratio for PM 

sampling.

(ii) Continuously measure constituent concentrations. For example, you might dilute to 

precondition a sample of raw exhaust to control its temperature, humidity, or constituent 

concentrations upstream of continuous analyzers. In this case, you must take into 

account the dilution ratio before multiplying the continuous concentration by the sampled 

exhaust flow rate. 

(iii) Extract a proportional sample from a separate constant dilution ratio PFD system. 

For example, you might use a variable-flow pump to proportionally fill a gaseous storage 

medium such as a bag from a PFD system. In this case, the proportional sampling must 

meet the same specifications as varying dilution ratio PFD in paragraph (d)(3) of this 

section.

(iv) For each mode of a discrete-mode test (such as a locomotive notch setting or a 

specific setting for speed and torque), use a constant dilution ratio for any PM sampling. 

You must change the overall PM sampling system dilution ratio between modes so that 

the dilution ratio on the mode with the highest exhaust flow rate meets § 1065.140(e)(2) 

and the dilution ratios on all other modes is higher than this (minimum) dilution ratio by

the ratio of the maximum exhaust flow rate to the exhaust flow rate of the corresponding 

other mode. This is the same dilution ratio requirement for RMC or field transient 

testing. You must account for this change in dilution ratio in your emission calculations.

(3) Varying dilution-ratio PFD. All the following provisions apply for varying dilutionratio PFD:

(i) Use a control system with sensors and actuators that can maintain proportional 

sampling over intervals as short as 200 ms (i.e., 5 Hz control).
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(ii) For control input, you may use any sensor output from one or more measurements; 

for example, intake-air flow, fuel flow, exhaust flow, engine speed, and intake manifold 

temperature and pressure.

(iii) Account for any emission transit time in the PFD system, as necessary.

(iv) You may use preprogrammed data if they have been determined for the specific test 

site, duty cycle, and test engine from which you dilute emissions.

(v) We recommend that you run practice cycles to meet the verification criteria in § 

1065.545. Note that you must verify every emission test by meeting the verification 

criteria with the data from that specific test. Data from previously verified practice cycles 

or other tests may not be used to verify a different emission test.

(vi) You may not use a PFD system that requires preparatory tuning or calibration with a 

CVS or with the emission results from a CVS. Rather, you must be able to independently 

calibrate the PFD.

(e) Dilution air temperature, dilution ratio, residence time, and temperature control of PM 

samples. Dilute PM samples at least once upstream of transfer lines. You may dilute PM 

samples upstream of a transfer line using full-flow dilution, or partial-flow dilution 

immediately downstream of a PM probe. In the case of partial-flow dilution, you may

have up to 26 cm of insulated length between the end of the probe and the dilution stage, 

but we recommend that the length be as short as practical. The intent of these 

specifications is to minimize heat transfer to or from the emission sample before the final 

stage of dilution, other than the heat you may need to add to prevent aqueous 

condensation. This is accomplished by initially cooling the sample through dilution. 

Configure dilution systems as follows:

(1) Set the dilution air temperature to (25 ±5) °C. Use good engineering judgment to 

select a location to measure this temperature that is as close as practical upstream of the 

point where dilution air mixes with raw exhaust. 

(2) For any PM dilution system (i.e., CVS or PFD), add dilution air to the raw exhaust 

such that the minimum overall ratio of diluted exhaust to raw exhaust is within the range 

of (5:1 to 7:1) and is at least 2:1 for any primary dilution stage. Base this minimum value 

on the maximum engine exhaust flow rate for a given test interval. Either measure the 

maximum exhaust flow during a practice run of the test interval or estimate it based on 

good engineering judgment (for example, you might rely on manufacturer-published 

literature).

(3) Configure any PM dilution system to have an overall residence time of (1.0 to 5.5) s, 

as measured from the location of initial dilution air introduction to the location where PM 

is collected on the sample media. Also configure the system to have a residence time of 

at least 0.50 s, as measured from the location of final dilution air introduction to the 

location where PM is collected on the sample media. When determining residence times 

within sampling system volumes, use an assumed flow temperature of 25 °C and pressure 

of 101.325 kPa.

(4) Control sample temperature to a (47 ±5) °C tolerance, as measured anywhere within 

20 cm upstream or downstream of the PM storage media (such as a filter). Measure this 

temperature with a bare-wire junction thermocouple with wires that are (0.500 ±0.025) 

mm diameter, or with another suitable instrument that has equivalent performance.
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 805 of 1039

250. Section 1065.145 is amended by revising paragraphs (a), (c)(1), (c)(2)(ii), 

(d)(1)(ii), (e)(2)(ii), and (e)(3)(ii) to read as follows:

§ 1065.145 Gaseous and PM probes, transfer lines, and sampling system 

components.

(a) Continuous and batch sampling. Determine the total mass of each constituent with 

continuous or batch sampling. Both types of sampling systems have probes, transfer 

lines, and other sampling system components that are described in this section.

* * * * *

(c) * * * 

(1) Probe design and construction. Use sample probes with inside surfaces of 300 series 

stainless steel or, for raw exhaust sampling, use any nonreactive material capable of 

withstanding raw exhaust temperatures. Locate sample probes where constituents are 

mixed to their mean sample concentration. Take into account the mixing of any 

crankcase emissions that may be routed into the raw exhaust. Locate each probe to 

minimize interference with the flow to other probes. We recommend that all probes 

remain free from influences of boundary layers, wakes, and eddies—especially near the 

outlet of a raw-exhaust stack where unintended dilution might occur. Make sure that 

purging or back-flushing of a probe does not influence another probe during testing. You 

may use a single probe to extract a sample of more than one constituent as long as the 

probe meets all the specifications for each constituent.

* * * * *

(2) * * * 

(ii) For probes that extract hydrocarbons for THC or NMHC analysis from the diluted 

exhaust of compression-ignition engines, two-stroke spark-ignition engines, or fourstroke spark-ignition engines at or below 19 kW, we recommend heating the probe to 

minimize hydrocarbon contamination consistent with good engineering judgment. If you 

routinely fail the contamination check in the 1065.520 pretest check, we recommend 

heating the probe section to approximately 190 °C to minimize contamination.

* * * * *

(d) * * *

(1) * * *

(ii) For THC transfer lines for testing compression-ignition engines, two-stroke sparkignition engines, or four-stroke spark-ignition engines at or below 19 kW, maintain a wall 

temperature tolerance throughout the entire line of (191 ±11) C. If you sample from raw 

exhaust, you may connect an unheated, insulated transfer line directly to a probe. Design 

the length and insulation of the transfer line to cool the highest expected raw exhaust 

temperature to no lower than 191 C, as measured at the transfer line’s outlet. For dilute 

sampling, you may use a transition zone between the probe and transfer line of up to 92 

cm to allow your wall temperature to transition to (191 ±11) °C.

* * * * *

(e) * * *

(2) * * *
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Page 806 of 1039

(ii) Thermal chiller. You may use a thermal chiller upstream of some gas analyzers and 

storage media. You may not use a thermal chiller upstream of a THC measurement 

system for compression-ignition engines, two-stroke spark-ignition engines, or fourstroke spark-ignition engines at or below 19 kW. If you use a thermal chiller upstream of 

an NO2-to-NO converter or in a sampling system without an NO2-to-NO converter, the 

chiller must meet the NO2 loss-performance check specified in § 1065.376. Monitor the 

dewpoint, Tdew, and absolute pressure, ptotal, downstream of a thermal chiller. You may

use continuously recorded values of Tdew and ptotal in the amount of water calculations 

specified in § 1065.645. If it is valid to assume the degree of saturation in the thermal 

chiller, you may calculate Tdew based on the known chiller performance and continuous 

monitoring of chiller temperature, Tchiller. If it is valid to assume a constant temperature 

offset between Tchiller and Tdew, due to a known and fixed amount of sample reheat 

between the chiller outlet and the temperature measurement location, you may factor in 

this assumed temperature offset value into emission calculations. If we ask for it, you 

must show by engineering analysis or by data the validity of any assumptions allowed by

this paragraph (e)(2)(ii). For our testing we may use average temperature and pressure 

values over the test interval or a nominal pressure value that we estimate as the dryer’s 

average pressure expected during testing as constant values in the calculations specified 

in § 1065.645. For your testing you may use the maximum temperature and minimum 

pressure values observed during a test interval or duty cycle or the high alarm 

temperature setpoint and the low alarm pressure setpoint as constant values in the amount 

of water calculations specified in § 1065.645. For your testing you may also use a 

nominal ptotal, which you may estimate as the dryer’s lowest absolute pressure expected 

during testing.

(3) * * *

(ii) For testing compression-ignition engines, two-stroke spark-ignition engines, or fourstroke spark-ignition engines at or below 19 kW, if you use a THC sample pump 

upstream of a THC analyzer or storage medium, its inner surfaces must be heated to a 

tolerance of (191 ±11) C.

* * * * *

251. Section 1065.170 is amended by revising paragraphs (a)(1), (b) including Table 1, 

(c)(1)(i), and Figure 1 to read as follows:

§ 1065.170 Batch sampling for gaseous and PM constituents.

* * * * *

(a) * * *

(1) Verify proportional sampling after an emission test as described in § 1065.545. Use 

good engineering judgment to select storage media that will not significantly change 

measured emission levels (either up or down). For example, do not use sample bags for 

storing emissions if the bags are permeable with respect to emissions or if they off gas 

emissions to the extent that it affects your ability to demonstrate compliance with the 

applicable gaseous emission standards. As another example, do not use PM filters that 

irreversibly absorb or adsorb gases to the extent that it affects your ability to demonstrate 

compliance with the applicable PM emission standard.
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 807 of 1039

* * * * *

(b) Gaseous sample storage media. Store gas volumes in sufficiently clean containers 

that minimally off-gas or allow permeation of gases. Use good engineering judgment to 

determine acceptable thresholds of storage media cleanliness and permeation. To clean a 

container, you may repeatedly purge and evacuate a container and you may heat it. Use a 

flexible container (such as a bag) within a temperature-controlled environment, or use a 

temperature controlled rigid container that is initially evacuated or has a volume that can 

be displaced, such as a piston and cylinder arrangement. Use containers meeting the 

specifications in the Table1 of this section, noting that you may request to use other 

container materials under § 1065.10. Sample temperatures must stay within the 

following ranges for each container material: 

(1) Up to 40 °C for TedlarTM and KynarTM.

(2) (191 ±11) °C for TeflonTM and 300 series stainless steel used with measuring THC or 

NMHC from compression-ignition engines, two-stroke spark-ignition engines, and fourstroke spark-ignition engines at or below 19 kW. For all other engines and pollutants, 

these materials may be used for sample temperatures up to 202 °C.

TABLE 1 OF § 1065.170– CONTAINER MATERIALS FOR GASEOUS BATCH SAMPLING

Emissions

Engine type

Compression-ignition

Two-stroke spark-ignition

Four-stroke spark-ignition at or below 

19 kW

All other engines

CO, CO2, O2,

CH4, C2H6, C3H8,

NO, NO2, N2O

TedlarTM, KynarTM, TeflonTM, or 300 

series stainless steel

TedlarTM, KynarTM, TeflonTM, or 

300 series stainless steel

THC, NMHC TeflonTM or

300 series stainless steel

TedlarTM, KynarTM, TeflonTM, or 

300 series stainless steel

(c) * * *

(1) * * *

(i) If you expect that a filter’s total surface concentration of PM will exceed 400 μg, 

assuming a 38 mm diameter filter stain area, for a given test interval, you may use filter 

media with a minimum initial collection efficiency of 98 %; otherwise you must use a 

filter media with a minimum initial collection efficiency of 99.7 %. Collection efficiency

must be measured as described in ASTM D2986 (incorporated by reference in § 

1065.1010), though you may rely on the sample-media manufacturer’s measurements 

reflected in their product ratings to show that you meet this requirement.

* * * * *
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 808 of 1039

0

0

.10-0.80 

BETWEEN 

IN ADDITION TO 

TYPICAL RANGES GIVEN FOR 

PERFORATION  AND 

PERFORATION PATTERNS, WE 

RECOMMEND THE FOLLOWING:
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 809 of 1039

Subpart C—[Amended]

252. Section 1065.201 is amended by revising paragraphs (b), (d), (e), and (h) to read 

as follows:

§ 1065.201 Overview and general provisions.

* * * * *

(b) Instrument types. You may use any of the specified instruments as described in this 

subpart to perform emission tests. If you want to use one of these instruments in a way 

that is not specified in this subpart, or if you want to use a different instrument, you must 

first get us to approve your alternate procedure under § 1065.10. Where we specify more 

than one instrument for a particular measurement, we may identify which instrument 

serves as the reference for comparing with an alternate procedure. You may generally 

use instruments with compensation algorithms that are functions of other gaseous 

measurements and the known or assumed fuel properties for the test fuel. The target 

value for any compensation algorithm is 0 % (that is, no bias high and no bias low), 

regardless of the uncompensated signal’s bias.

* * * * *

(d) Redundant systems. For all measurement instruments described in this subpart, you 

may use data from multiple instruments to calculate test results for a single test. If you 

use redundant systems, use good engineering judgment to use multiple measured values 

in calculations or to disregard individual measurements. Note that you must keep your 

results from all measurements. This requirement applies whether or not you actually use 

the measurements in your calculations.

(e) Range. You may use an instrument’s response above 100 % of its operating range if 

this does not affect your ability to show that your engines comply with the applicable 

emission standards. Note that we require additional testing and reporting if an analyzer 

responds above 100 % of its range. Auto-ranging analyzers do not require additional 

testing or reporting.

* * * * *

(h) Recommended practices. This subpart identifies a variety of recommended but not

required practices for proper measurements. We believe in most cases it is necessary to 

follow these recommended practices for accurate and repeatable measurements. 

However, we do not specifically require you to follow these recommended practices to 

perform a valid test, as long as you meet the required calibrations and verifications of 

measurement systems specified in subpart D of this part. Similarly, we are not required 

to follow all recommended practices, as long as we meet the required calibrations and 

verifications. Our decision to follow or not follow a given recommendation when we 

perform a test does not depend on whether you followed it during your testing.

253. Section 1065.202 is revised to read as follows:

§ 1065.202 Data updating, recording, and control.

Your test system must be able to update data, record data and control systems related to 

operator demand, the dynamometer, sampling equipment, and measurement instruments. 
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Page 810 of 1039

Use data acquisition and control systems that can record at the specified minimum 

frequencies, as follows:

TABLE 1 OF § 1065.202–DATA RECORDING AND CONTROL MINIMUM FREQUENCIES

Applicable 

Test Protocol 

Section

Measured Values

Minimum 

Command and 

Control 

Frequencya

Minimum 

Recording 

Frequencyb,c

§ 1065.510 Speed and torque during an engine step-map 1 Hz 1 mean value 

per step

§ 1065.510 Speed and torque during an engine sweep-map 5 Hz 1 Hz means

§ 1065.514

§ 1065.530

Transient duty cycle reference and feedback speeds 

and torques 5 Hz 1 Hz means

§ 1065.514

§ 1065.530

Steady-state and ramped-modal duty cycle reference 

and feedback speeds and torques 1 Hz 1 Hz

§ 1065.520

§ 1065.530

§ 1065.550

Continuous concentrations of raw or dilute analyzers — 1 Hz

§ 1065.520

§ 1065.530

§ 1065.550

Batch concentrations of raw or dilute analyzers —

1 mean value 

per test interval

§ 1065.530

§ 1065.545

Diluted exhaust flow rate from a CVS with a heat 

exchanger upstream of the flow measurement — 1 Hz

§ 1065.530

§ 1065.545

Diluted exhaust flow rate from a CVS without a heat 

exchanger upstream of the flow measurement 5 Hz 1 Hz means

§ 1065.530

§ 1065.545 Intake-air or raw-exhaust flow rate — 1 Hz means

§ 1065.530

§ 1065.545

Dilution air flow if actively controlled (for example, 

a partial-flow PM sampling system)d 5 Hz 1 Hz means

§ 1065.530

§ 1065.545 Sample flow from a CVS that has a heat exchanger 1 Hz 1 Hz

§ 1065.530

§ 1065.545

Sample flow from a CVS that does not have a heat 

exchanger 5 Hz 1 Hz means

a The specifications for minimum command and control frequency do not apply for CFVs that are not using 

active control .

b

1 Hz means are data reported from the instrument at a higher frequency, but recorded as a series of 1 s 

mean values at a rate of 1 Hz.

c

For CFVs in a CVS, the minimum recording frequency is 1 Hz. The minimum recording frequency does 

not apply for CFVs used to control sampling from a CVS utilizing CFVs.

dDilution air flow specifications do not apply for CVS dilution air.

254. Section 1065.205 is revised to read as follows:

§ 1065.205 Performance specifications for measurement instruments.

Your test system as a whole must meet all the calibrations, verifications, and testvalidation criteria specified outside this section for laboratory testing or field testing, as 

applicable. We recommend that your instruments meet the specifications in Table 1 of 

this section for all ranges you use for testing. We also recommend that you keep any 

documentation you receive from instrument manufacturers showing that your instruments 

meet the specifications in Table 1 of this section.
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 811 of 1039

TABLE 1 OF § 1065.205–RECOMMENDED PERFORMANCE SPECIFICATIONS FOR MEASUREMENT INSTRUMENTS

Measurement Instrument

Measure

d 

quantity 

symbol

Complete System

Rise time (t10-90) and 

Fall time (t90-10)

a

Recording

update frequency Accuracyb Repeatabilityb Noiseb

Engine speed transducer fn 1 s 1 Hz means 2 % of pt. or

0.5 % of max.

1 % of pt. or

0.25 % of max. 0.05 % of max

Engine torque transducer T 1 s 1 Hz means 2 % of pt. or

1 % of max.

1 % of pt. or

0.5 % of max 0.05 % of max.

Electrical work (active-power meter) W 1 s 1 Hz means 2 % of pt. or

0.5 % of max.

1 % of pt. or

0.25 % of max. 0.05 % of max

General pressure transducer (not a part 

of another instrument) p 5 s 1 Hz 2 % of pt. or1 % of max.

1 % of pt. or

0.5 % of max. 0.1 % of max

Atmospheric pressure meter for PMstabilization and balance environments patmos 50 s 5 times per hour 50 Pa 25 Pa 5 Pa

General purpose atmospheric pressure 

meter patmos 50 s 5 times per hour 250 Pa 100Pa 50 Pa

Temperature sensor for PMstabilization and balance environments T 50 s 0.1 Hz 0.25 K 0.1 K 0.1 K

Other temperature sensor (not a part of 

another instrument) T 10 s 0.5 Hz 0.4 % of pt. K or0.2 % of max. K

0.2 % of pt. K or

0.1 % of max. K 0.1 % of max

Dewpoint sensor for intake air, PMstabilization and balance environments Tdew 50 s 0.1 Hz 0.25 K 0.1 K 0.02 K

Other dewpoint sensor Tdew 50 s 0.1 Hz 1 K 0.5 K 0.1 K

Fuel flow meterc

(Fuel totalizer) m

5 s

(—)

1 Hz

(—)

2 % of pt. or

1.5 % of max.

1 % of pt. or

0.75 % of max. 0.5 % of max.

Total diluted exhaust meter (CVS) c

(With heat exchanger before meter) n

1 s

(5 s)

1 Hz means

(1 Hz)

2 % of pt. or

1.5 % of max.

1 % of pt. or

0.75 % of max. 1 % of max.

Dilution air, inlet air, exhaust, and 

sample flow metersc n 1 s 1 Hz means of 5 Hz samples

2.5 % of pt. or

1.5 % of max.

1.25 % of pt. or

0.75 % of max. 1 % of max.

Continuous gas analyzer x 5 s 1 Hz 2 % of pt. or

2 % of meas.

1 % of pt. or

1 % of meas. 1 % of max.

Batch gas analyzer x — —

2 % of pt. or

2 % of meas.

1 % of pt. or

1 % of meas. 1 % of max.

Gravimetric PM balance mPM — — See § 1065.790 0.5 g —

Inertial PM balance mPM 5 s 1 Hz 2 % of pt. or

2 % of meas.

1 % of pt. or

1 % of meas. 0.2 % of max.

a The performance specifications identified in the table apply separately for rise time and fall time.

b Accuracy, repeatability, and noise are all determined with the same collected data, as described in § 1065.305, and based on absolute values. “pt.” refers to the overall flowweighted mean value expected at the standard; “max.” refers to the peak value expected at the standard over any test interval, not the maximum of the instrument’s range; “meas” 

refers to the actual flow-weighted mean measured over any test interval.
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c The procedure for accuracy, repeatability and noise measurement described in § 1065.305 may be modified for flow meters to allow noise to be measured at the lowest calibrated 

value instead of zero flow rate.
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255. Section 1065.210 is amended by revising paragraph (c) to read as follows:

§ 1065.210 Work input and output sensors.

* * * * *

(c) Electrical work. Use a watt-hour meter output to calculate total work according to § 

1065.650. Use a watt-hour meter that outputs active power. Watt-hour meters typically

combine a Wheatstone bridge voltmeter and a Hall-effect clamp-on ammeter into a single 

microprocessor-based instrument that analyzes and outputs several parameters, such as 

alternating or direct current voltage, current, power factor, apparent power, reactive 

power, and active power.

* * * * *

256. Section 1065.225 is amended by revising paragraph (a) to read as follows:

§ 1065.225 Intake-air flow meter.

(a) Application. You may use an intake-air flow meter in combination with a chemical 

balance of fuel, inlet air, and exhaust to calculate raw exhaust flow as described in § 

1065.655(e) and (f), as follows:

(1) Use the actual value of calculated raw exhaust in the following cases:

(i) For multiplying raw exhaust flow rate with continuously sampled concentrations.

(ii) For multiplying total raw exhaust flow with batch-sampled concentrations.

(iii) For verifying minimum dilution ratio for PM batch sampling as described in § 

1065.546.

(iv) For calculating the dilution air flow for background correction as described in § 

1065.667.

(2) In the following cases, you may use an intake-air flow meter signal that does not give 

the actual value of raw exhaust, as long as it is linearly proportional to the exhaust flow 

rate’s actual calculated value:

(i) For feedback control of a proportional sampling system, such as a partial-flow dilution 

system.

(ii) For multiplying with continuously sampled gas concentrations, if the same signal is 

used in a chemical-balance calculation to determine work from brake-specific fuel 

consumption and fuel consumed.

* * * * *

257. Section 1065.230 is amended by revising paragraph (d) to read as follows:

§ 1065.230 Raw exhaust flow meter.

* * * * *

(d) Exhaust cooling. You may cool raw exhaust upstream of a raw-exhaust flow meter, 

as long as you observe all the following provisions: 

(1) Do not sample PM downstream of the cooling.

(2) If cooling causes exhaust temperatures above 202 °C to decrease to below 180 °C, do 

not sample NMHC downstream of the cooling for compression-ignition engines, twostroke spark-ignition engines, or four-stroke spark-ignition engines at or below 19 kW.

(3) The cooling must not cause aqueous condensation.
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258. Section 1065.240 is amended by revising paragraph (d) to read as follows:

§ 1065.240 Dilution air and diluted exhaust flow meters.

* * * * *

(d) Exhaust cooling. You may cool diluted exhaust upstream of a dilute-exhaust flow 

meter, as long as you observe all the following provisions: 

(1) Do not sample PM downstream of the cooling.

(2) If cooling causes exhaust temperatures above 202 °C to decrease to below 180 °C, do 

not sample NMHC downstream of the cooling for compression-ignition engines, twostroke spark-ignition engines, or four-stroke spark-ignition engines at or below 19 kW.

(3) The cooling must not cause aqueous condensation as described in § 1065.140(c)(6).

259. Section 1065.250 is amended by revising paragraph (b) to read as follows:

§ 1065.250 Nondispersive infrared analyzer.

* * * * *

(b) Component requirements. We recommend that you use an NDIR analyzer that meets 

the specifications in Table 1 of § 1065.205. Note that your NDIR-based system must 

meet the calibration and verifications in §§ 1065.350 and 1065.355 and it must also meet 

the linearity verification in § 1065.307.

260. Section 1065.260 is amended by revising paragraphs (b), (c), and (e) to read as 

follows:

§ 1065.260 Flame-ionization detector.

* * * * *

(b) Component requirements. We recommend that you use a FID analyzer that meets the 

specifications in Table 1 of § 1065.205. Note that your FID-based system for measuring 

THC, THCE, or CH4 must meet all the verifications for hydrocarbon measurement in 

subpart D of this part, and it must also meet the linearity verification in § 1065.307.

(c) Heated FID analyzers. For measuring THC or THCE from compression-ignition 

engines, two-stroke spark-ignition engines, and four-stroke spark-ignition engines at or 

below 19 kW, you must use heated FID analyzers that maintain all surfaces that are 

exposed to emissions at a temperature of (191 ±11) °C.

* * * * *

(e) NMHC and NMOG. For demonstrating compliance with NMHC standards, you may

either measure THC and CH4 and determine NMHC as described in § 1065.660(b)(2) or 

(3), or you may measure THC and determine NMHC mass as described in § 

1065.660(b)(1). See 40 CFR 1066.635 for methods to demonstrate compliance with 

NMOG standards for vehicle testing.

* * * * *

261. Section 1065.267 is amended by revising paragraph (b) to read as follows:

§ 1065.267 Gas chromatograph with a flame ionization detector.

* * * * *

(b) Component requirements. We recommend that you use a GC-FID that meets the 

specifications in Table 1 of § 1065.205 and that the measurement be done according to 
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Page 815 of 1039

SAE J1151 (incorporated by reference in § 1065.1010). The GC-FID must meet the 

linearity verification in § 1065.307.

262. A new § 1065.269 is added to subpart C under the center header “Hydrocarbon 

Measurements” to read as follows:

§ 1065.269 Photoacoustic analyzer for ethanol and methanol.

(a) Application. You may use a photoacoustic analyzer to measure ethanol and/or 

methanol concentrations in diluted exhaust for batch sampling.

(b) Component requirements. We recommend that you use a photoacoustic analyzer that 

meets the specifications in Table 1 of § 1065.205. Note that your photoacoustic system 

must meet the verification in § 1065.369 and it must also meet the linearity verification in 

§ 1065.307. Use an optical wheel configuration that gives analytical priority to 

measurement of the least stable components in the sample. Select a sample integration 

time of at least 5 seconds. Take into account sample chamber and sample line volumes 

when determining flush times for your instrument.

263. Section 1065.270 is amended by revising paragraph (b) to read as follows:

§ 1065.270 Chemiluminescent detector.

* * * * *

(b) Component requirements. We recommend that you use a CLD that meets the 

specifications in Table 1 of § 1065.205. Note that your CLD-based system must meet the 

quench verification in § 1065.370 and it must also meet the linearity verification in § 

1065.307. You may use a heated or unheated CLD, and you may use a CLD that 

operates at atmospheric pressure or under a vacuum.

* * * * *

264. Section 1065.272 is amended by revising paragraph (b) to read as follows:

§ 1065.272 Nondispersive ultraviolet analyzer.

* * * * *

(b) Component requirements. We recommend that you use an NDUV analyzer that 

meets the specifications in Table 1 of § 1065.205. Note that your NDUV-based system 

must meet the verifications in § 1065.372 and it must also meet the linearity verification 

in § 1065.307.

* * * * *

265. Section 1065.275 is amended by revising paragraph (b) to read as follows:

§ 1065.275 N2O measurement devices.

* * * * *

(b) Instrument types. You may use any of the following analyzers to measure N2O:

(1) Nondispersive infrared (NDIR) analyzer.

(2) Fourier transform infrared (FTIR) analyzer. Use appropriate analytical procedures for 

interpretation of infrared spectra. For example, EPA Test Method 320 is considered a 

valid method for spectral interpretation (see 

http://www.epa.gov/ttn/emc/methods/method320.html).
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(3) Laser infrared analyzer. Examples of laser infrared analyzers are pulsed-mode highresolution narrow band mid-infrared analyzers, and modulated continuous wave highresolution narrow band mid-infrared analyzers.

(4) Photoacoustic analyzer. Use an optical wheel configuration that gives analytical 

priority to measurement of the least stable components in the sample. Select a sample 

integration time of at least 5 seconds. Take into account sample chamber and sample line 

volumes when determining flush times for your instrument.

(5) Gas chromatograph analyzer. You may use a gas chromatograph with an electroncapture detector (GC-ECD) to measure N2O concentrations of diluted exhaust for batch 

sampling.

(i)You may use a packed or porous layer open tubular (PLOT) column phase of suitable 

polarity and length to achieve adequate resolution of the N2O peak for analysis. 

Examples of acceptable columns are a PLOT column consisting of bonded polystyrenedivinylbenzene or a Porapack Q packed column. Take the column temperature profile 

and carrier gas selection into consideration when setting up your method to achieve 

adequate N2O peak resolution.

(ii) Use good engineering judgment to zero your instrument and correct for drift. You do 

not need to follow the specific procedures in §§ 1065.530 and 1065.550(b) that would 

otherwise apply. For example, you may perform a span gas measurement before and 

after sample analysis without zeroing and use the average area counts of the pre-span and 

post-span measurements to generate a response factor (area counts/span gas 

concentration), which you then multiply by the area counts from your sample to generate 

the sample concentration.

* * * * *

266. Section 1065.280 is amended by revising paragraph (b) to read as follows:

§ 1065.280 Paramagnetic and magnetopneumatic O2 detection analyzers.

* * * * *

(b) Component requirements. We recommend that you use a PMD or MPD analyzer that 

meets the specifications in Table 1 of § 1065.205. Note that it must meet the linearity 

verification in § 1065.307.

267. Section 1065.284 is amended by revising paragraph (b) to read as follows:

§ 1065.284 Zirconia (ZrO2) analyzer.

* * * * *

(b) Component requirements. We recommend that you use a ZrO2 analyzer that meets 

the specifications in Table 1 of § 1065.205. Note that your ZrO2-based system must meet 

the linearity verification in § 1065.307.

268. Section 1065.295 is amended by revising paragraph (b) to read as follows:

§ 1065.295 PM inertial balance for field-testing analysis.

* * * * *

(b) Component requirements. We recommend that you use a balance that meets the 

specifications in Table 1 of § 1065.205. Note that your balance-based system must meet 
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the linearity verification in § 1065.307. If the balance uses an internal calibration process 

for routine spanning and linearity verifications, the process must be NIST-traceable.

* * * * *

Subpart D—[Amended]

269. Section 1065.303 is revised to read as follows:

§ 1065.303 Summary of required calibration and verifications.

The following table summarizes the required and recommended calibrations and 

verifications described in this subpart and indicates when these have to be performed:

TABLE 1 OF § 1065.303–SUMMARY OF REQUIRED CALIBRATION AND VERIFICATIONS

Type of calibration or verification Minimum frequency1

§ 1065.305: Accuracy, repeatability and noise

Accuracy: Not required, but recommended for initial installation.

Repeatability: Not required, but recommended for initial 

installation.

Noise: Not required, but recommended for initial installation.

§ 1065.307: Linearity verification

Speed: Upon initial installation, within 370 days before testing 

and after major maintenance.

Torque: Upon initial installation, within 370 days before testing 

and after major maintenance.

Electrical power, current, and voltage: Upon initial installation, 

within 370 days before testing and after major maintenance.2

Fuel flow rate: Upon initial installation, within 370 days before 

testing, and after major maintenance.

Intake-air, dilution air, diluted exhaust, and batch sampler flow 

rates: Upon initial installation, within 370 days before testing and 

after major maintenance, unless flow is verified by propane check 

or by carbon or oxygen balance.

Raw exhaust flow rate: Upon initial installation, within 185 days 

before testing and after major maintenance, unless flow is verified 

by propane check or by carbon or oxygen balance.

Gas dividers: Upon initial installation, within 370 days before 

testing, and after major maintenance.

Gas analyzers (unless otherwise noted): Upon initial installation, 

within 35 days before testing and after major maintenance.

FTIR and photoacoustic analyzers: Upon initial installation, 

within 370 days before testing and after major maintenance.

GC-ECD: Upon initial installation and after major maintenance.

PM balance: Upon initial installation, within 370 days before 

testing and after major maintenance.

Pressure, temperature, and dewpoint: Upon initial installation, 

within 370 days before testing and after major maintenance.

§ 1065.308: Continuous gas analyzer system 

response and updating-recording verification—

for gas analyzers not continuously compensated 

for other gas species

Upon initial installation or after system modification that would 

affect response.

§ 1065.309: Continuous gas analyzer systemresponse and updating-recording verification—

for gas analyzers continuously compensated for 

other gas species

Upon initial installation or after system modification that would 

affect response.

§ 1065.310: Torque Upon initial installation and after major maintenance.

§ 1065.315: Pressure, temperature, dewpoint Upon initial installation and after major maintenance.

§ 1065.320: Fuel flow Upon initial installation and after major maintenance.

§ 1065.325: Intake flow Upon initial installation and after major maintenance.
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§ 1065.330: Exhaust flow Upon initial installation and after major maintenance.

§ 1065.340: Diluted exhaust flow (CVS) Upon initial installation and after major maintenance.

§ 1065.341: CVS and batch sampler verification3 Upon initial installation, within 35 days before testing, and after 

major maintenance.

§ 1065.342 Sample dryer verification

For thermal chillers: upon installation and after major 

maintenance.

For osmotic membranes; upon installation, within 35 days of 

testing, and after major maintenance.

§ 1065.345: Vacuum leak

For laboratory testing: upon initial installation of the sampling 

system, within 8 hours before the start of the first test interval of 

each duty-cycle sequence, and after maintenance such as pre-filter 

changes.

For field testing: after each installation of the sampling system on 

the vehicle, prior to the start of the field test, and after 

maintenance such as pre-filter changes.

§ 1065.350: CO2 NDIR H2O interference Upon initial installation and after major maintenance.

§ 1065.355: CO NDIR CO2 and H2O interference Upon initial installation and after major maintenance.

§ 1065.360: FID calibration

THC FID optimization, and THC FID verification

Calibrate all FID analyzers: upon initial installation and after 

major maintenance.

Optimize and determine CH4response for THC FID analyzers:

upon initial installation and after major maintenance.

Verify CH4response for THC FID analyzers: upon initial 

installation, within 185 days before testing, and after major 

maintenance.

§ 1065.362: Raw exhaust FID O2interference

For all FID analyzers: upon initial installation, and after major 

maintenance.

For THC FID analyzers: upon initial installation, after major 

maintenance, and after FID optimization according to § 1065.360.

§ 1065.365: Nonmethane cutter penetration Upon initial installation, within 185 days before testing, and after 

major maintenance.

§ 1065.369: H2O, CO, and CO2interference 

verification for ethanol photoacoustic analyzers Upon initial installation and after major maintenance.

§ 1065.370: CLD CO2 and H2O quench Upon initial installation and after major maintenance.

§ 1065.372: NDUV HC and H2O interference Upon initial installation and after major maintenance.

§ 1065.375: N2O analyzer interference Upon initial installation and after major maintenance.

§ 1065.376: Chiller NO2 penetration Upon initial installation and after major maintenance.

§ 1065.378: NO2-to-NO converter conversion Upon initial installation, within 35 days before testing, and after 

major maintenance.

§ 1065.390: PM balance and weighing

Independent verification: upon initial installation, within 370 days 

before testing, and after major maintenance.

Zero, span, and reference sample verifications: within 12 hours of 

weighing, and after major maintenance.

§ 1065.395: Inertial PM balance and weighing

Independent verification: upon initial installation, within 370 days 

before testing, and after major maintenance.

Other verifications: upon initial installation and after major 

maintenance.

1

Perform calibrations and verifications more frequently than we specify, according to measurement system 

manufacturer instructions and good engineering judgment.

2

Perform linearity verification either for electrical power or for current and voltage.

3The CVS verification described in § 1065.341 is not required for systems that agree within ±2 % based on a chemical 

balance of carbon or oxygen of the intake air, fuel, and diluted exhaust.

270. Section 1065.305 is amended by revising paragraph (d)(10)(i) to read as follows:

§ 1065.305 Verifications for accuracy, repeatability, and noise.

* * * * *

(d) * * *
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(10) * * *

(i) Your measurement systems meet all the other required calibration, verification, and 

validation specifications that apply as specified in the regulations.

* * * * *

271. Section 1065.307 is revised to read as follows:

§ 1065.307 Linearity verification.

(a) Scope and frequency. Perform linearity verification on each measurement system 

listed in Table 1 of this section at least as frequently as indicated in Table 1 of § 

1065.303, consistent with measurement system manufacturer’s recommendations and 

good engineering judgment. The intent of linearity verification is to determine that a 

measurement system responds accurately and proportionally over the measurement range 

of interest. Linearity verification generally consists of introducing a series of at least 10 

reference values to a measurement system. The measurement system quantifies each 

reference value. The measured values are then collectively compared to the reference 

values by using a least-squares linear regression and the linearity criteria specified in 

Table 1 of this section.

(b) Performance requirements. If a measurement system does not meet the applicable 

linearity criteria referenced in Table 1 of this section, correct the deficiency by recalibrating, servicing, or replacing components as needed. Repeat the linearity

verification after correcting the deficiency to ensure that the measurement system meets 

the linearity criteria. Before you may use a measurement system that does not meet 

linearity criteria, you must demonstrate to us that the deficiency does not adversely affect 

your ability to demonstrate compliance with the applicable standards.

(c) Procedure. Use the following linearity verification protocol, or use good engineering 

judgment to develop a different protocol that satisfies the intent of this section, as 

described in paragraph (a) of this section:

(1) In this paragraph (c), the letter “y” denotes a generic measured quantity, the 

superscript over-bar denotes an arithmetic mean (such as y ), and the subscript “ref” 

denotes the known or reference quantity being measured.

(2) Use good engineering judgment to operate a measurement system at normal operating 

conditions. This may include any specified adjustment or periodic calibration of the 

measurement system.

(3) If applicable, zero the instrument as you would before an emission test by introducing 

a zero signal. Depending on the instrument, this may be a zero-concentration gas, a 

reference signal, a set of reference thermodynamic conditions, or some combination of 

these. For gas analyzers, use a zero gas that meets the specifications of § 1065.750 and 

introduce it directly at the analyzer port.

(4) If applicable, span the instrument as you would before an emission test by introducing 

a span signal. Depending on the instrument, this may be a span-concentration gas, a 

reference signal, a set of reference thermodynamic conditions, or some combination of 

these. For gas analyzers, use a span gas that meets the specifications of § 1065.750 and 

introduce it directly at the analyzer port.
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(5) If applicable, after spanning the instrument, check zero with the same signal you used 

in paragraph (c)(3) of this section. Based on the zero reading, use good engineering 

judgment to determine whether or not to rezero and or re-span the instrument before 

continuing.

(6) For all measured quantities, use the instrument manufacturer’s recommendations and 

good engineering judgment to select reference values, yrefi, that cover a range of values 

that you expect would prevent extrapolation beyond these values during emission testing. 

We recommend selecting a zero reference signal as one of the reference values for the 

linearity verification. For pressure, temperature, dewpoint, power, current, voltage, 

photoacoustic analyzers, and GC-ECD linearity verifications, we recommend at least 

three reference values. For all other linearity verifications select at least ten reference 

values.

(7) Use the instrument manufacturer’s recommendations and good engineering judgment 

to select the order in which you will introduce the series of reference values. For 

example, you may select the reference values randomly to avoid correlation with 

previous measurements and to avoid hysteresis; you may select reference values in 

ascending or descending order to avoid long settling times of reference signals; or you 

may select values to ascend and then descend to incorporate the effects of any instrument 

hysteresis into the linearity verification.

(8) Generate reference quantities as described in paragraph (d) of this section. For gas 

analyzers, use gas concentrations known to be within the specifications of § 1065.750 

and introduce them directly at the analyzer port.

(9) Introduce a reference signal to the measurement instrument.

(10) Allow time for the instrument to stabilize while it measures the value at the 

reference condition. Stabilization time may include time to purge an instrument and time 

to account for its response.

(11) At a recording frequency of at least f Hz, specified in Table 1 of § 1065.205, 

measure the value at the reference condition for 30 seconds (you may select a longer 

sampling period if the recording update frequency is less than 0.5 Hz) and record the 

arithmetic mean of the recorded values, i

y . Refer to § 1065.602 for an example of 

calculating an arithmetic mean.

(12) Repeat the steps in paragraphs (c)(9) though (11) of this section until measurements 

are complete at each of the reference conditions.

(13) Use the arithmetic means, i

y , and reference values, yrefi , to calculate least-squares 

linear regression parameters and statistical values to compare to the minimum 

performance criteria specified in Table 1 of this section. Use the calculations described 

in § 1065.602. Using good engineering judgment, you may weight the results of 

individual data pairs (i.e. (yrefi, i

y )), in the linear regression calculations.

(d) Reference signals. This paragraph (d) describes recommended methods for 

generating reference values for the linearity-verification protocol in paragraph (c) of this 

section. Use reference values that simulate actual values, or introduce an actual value

and measure it with a reference-measurement system. In the latter case, the reference 

value is the value reported by the reference-measurement system. Reference values and 

reference-measurement systems must be NIST-traceable. We recommend using 
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calibration reference quantities that are NIST-traceable within 0.5 % uncertainty, if not 

specified elsewhere in this part 1065. Use the following recommended methods to 

generate reference values or use good engineering judgment to select a different 

reference:

(1) Speed. Run the engine or dynamometer at a series of steady-state speeds and use a 

strobe, photo tachometer, or laser tachometer to record reference speeds.

(2) Torque. Use a series of calibration weights and a calibration lever arm to simulate 

engine torque. You may instead use the engine or dynamometer itself to generate a 

nominal torque that is measured by a reference load cell or proving ring in series with the 

torque-measurement system. In this case, use the reference load cell measurement as the 

reference value. Refer to § 1065.310 for a torque-calibration procedure similar to the 

linearity verification in this section.

(3) Electrical power, current, and voltage. You must perform linearity verification for 

either electrical power meters, or for current and voltage meters. Perform linearity 

verifications using a reference meter and controlled sources of current and voltage. We 

recommend using a complete calibration system that is suitable for the electrical power 

distribution industry.

(4) Fuel rate. Operate the engine at a series of constant fuel-flow rates or re-circulate fuel 

back to a tank through the fuel flow meter at different flow rates. Use a gravimetric 

reference measurement (such as a scale, balance, or mass comparator) at the inlet to the 

fuel-measurement system. Use a stopwatch or timer to measure the time intervals over 

which reference masses of fuel are introduced to the fuel measurement system. The 

reference fuel mass divided by the time interval is the reference fuel flow rate.

(5) Flow rates—inlet air, dilution air, diluted exhaust, raw exhaust, or sample flow. Use a 

reference flow meter with a blower or pump to simulate flow rates. Use a restrictor, 

diverter valve, a variable-speed blower or a variable-speed pump to control the range of 

flow rates. Use the reference meter’s response as the reference values.

(i) Reference flow meters. Because the flow range requirements for these various flows 

are large, we allow a variety of reference meters. For example, for diluted exhaust flow 

for a full-flow dilution system, we recommend a reference subsonic venturi flow meter 

with a restrictor valve and a blower to simulate flow rates. For inlet air, dilution air, 

diluted exhaust for partial-flow dilution, raw exhaust, or sample flow, we allow reference 

meters such as critical flow orifices, critical flow venturis, laminar flow elements, master 

mass flow standards, or Roots meters. Make sure the reference meter is calibrated and its 

calibration is NIST-traceable. If you use the difference of two flow measurements to 

determine a net flow rate, you may use one of the measurements as a reference for the 

other.

(ii) Reference flow values. Because the reference flow is not absolutely constant, sample 

and record values of refi n for 30 seconds and use the arithmetic mean of the values, ref n , 

as the reference value. Refer to § 1065.602 for an example of calculating arithmetic 

mean.

(6) Gas division. Use one of the two reference signals:

(i) At the outlet of the gas-division system, connect a gas analyzer that meets the linearity 

verification described in this section and has not been linearized with the gas divider 
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being verified. For example, verify the linearity of an analyzer using a series of reference 

analytical gases directly from compressed gas cylinders that meet the specifications of § 

1065.750. We recommend using a FID analyzer or a PMD or MPD O2 analyzer because 

of their inherent linearity. Operate this analyzer consistent with how you would operate 

it during an emission test. Connect a span gas to the gas-divider inlet. Use the gasdivision system to divide the span gas with purified air or nitrogen. Select gas divisions 

that you typically use. Use a selected gas division as the measured value. Use the 

analyzer response divided by the span gas concentration as the reference gas-division 

value. Because the instrument response is not absolutely constant, sample and record 

values of xrefi for 30 seconds and use the arithmetic mean of the values, ref x , as the 

reference value. Refer to § 1065.602 for an example of calculating arithmetic mean.

(ii) Using good engineering judgment and the gas divider manufacturer’s 

recommendations, use one or more reference flow meters to measure the flow rates of the 

gas divider and verify the gas-division value.

(7) Continuous constituent concentration. For reference values, use a series of gas 

cylinders of known gas concentration or use a gas-division system that is known to be

linear with a span gas. Gas cylinders, gas-division systems, and span gases that you use 

for reference values must meet the specifications of § 1065.750.

(8) Temperature. You may perform the linearity verification for temperature 

measurement systems with thermocouples, RTDs, and thermistors by removing the 

sensor from the system and using a simulator in its place. Use a NIST-traceable 

simulator that is independently calibrated and, as appropriate, cold-junctioncompensated. The simulator uncertainty scaled to absolute temperature must be less than 

0.5 % of Tmax. If you use this option, you must use sensors that the supplier states are 

accurate to better than 0.5 % of Tmax compared with their standard calibration curve.

(9) Mass. For linearity verification for gravimetric PM balances, use external calibration 

weights that meet the requirements in § 1065.790.

(e) Measurement systems that require linearity verification. Table 1 of this section 

indicates measurement systems that require linearity verification, subject to the following 

provisions:

(1) Perform linearity verification more frequently based on the instrument manufacturer’s 

recommendation or good engineering judgment.

(2) The expression “xmin” refers to the reference value used during linearity verification 

that is closest to zero. This is the value used to calculate the first tolerance in Table 1 of 

this section using the intercept, a0. Note that this value may be zero, positive, or negative 

depending on the reference values. For example, if the reference values chosen to 

validate a pressure transducer vary from -10 to -1 kPa, xmin is -1 kPa. If the reference 

values used to validate a temperature device vary from 290 to 390 K, xmin is 290 K.

(3) The expression “max” generally refers to the absolute value of the reference value 

used during linearity verification that is furthest from zero. This is the value used to scale 

the first and third tolerances in Table 1 of this section using a0 and SEE. For example, if 

the reference values chosen to validate a pressure transducer vary from -10 to -1 kPa, 

then pmax is +10 kPa. If the reference values used to validate a temperature device vary

from 290 to 390 K, then Tmax is 390 K. For gas dividers where “max” is expressed as, 
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xmax/xspan; xmax is the maximum gas concentration used during the verification, xspan is the 

undivided, undiluted, span gas concentration, and the resulting ratio is the maximum 

divider point reference value used during the verification (typically 1). The following are 

special cases where “max” refers to a different value:

(i) For linearity verification with a PM balance, mmax refers to the typical mass of a PM 

filter.

(ii) For linearity verification of torque on the engine’s primary output shaft, Tmax refers to 

the manufacturer’s specified engine torque peak value of the lowest torque engine to be 

tested.

(4) The specified ranges are inclusive. For example, a specified range of 0.98-1.02 for a1

means 0.98a11.02.

(5) Linearity verification is optional for systems that pass the flow-rate verification for 

diluted exhaust as described in § 1065.341 (the propane check) or for systems that agree 

within ±2 % based on a chemical balance of carbon or oxygen of the intake air, fuel, and 

exhaust.

(6) You must meet the a1 criteria for these quantities only if the absolute value of the 

quantity is required, as opposed to a signal that is only linearly proportional to the actual 

value.

(7) Linearity verification is required for the following temperature measurements:

(i) The following temperature measurements always require linearity verification:

(A) Air intake.

(B) Aftertreatment bed(s), for engines tested with aftertreatment devices subject to coldstart testing.

(C) Dilution air for gaseous and PM sampling, including CVS, double-dilution, and 

partial-flow systems.

(D) PM sample.

(E) Chiller sample, for gaseous sampling systems that use thermal chillers to dry samples

and use chiller temperature to calculate the dewpoint at the outlet of the chiller. For your 

testing, if you choose to use a high alarm temperature setpoint for the chiller temperature 

as a constant value in determining the amount of water removed from the emission 

sample, you may use good engineering judgment to verify the accuracy of the high alarm 

temperature setpoint instead of linearity verification on the chiller temperature. To verify

that the alarm trip point value is no less than 2.0 °C below the reference value at the trip 

point, we recommend that you input a reference simulated temperature signal below the 

alarm trip point and increase this signal until the high alarm trips.

(ii) Linearity verification is required for the following temperature measurements if these 

temperature measurements are specified by the engine manufacturer:

(A) Fuel inlet.

(B) Air outlet to the test cell’s charge air cooler air outlet, for engines tested with a 

laboratory heat exchanger that simulates an installed charge air cooler.

(C) Coolant inlet to the test cell’s charge air cooler, for engines tested with a laboratory

heat exchanger that simulates an installed charge air cooler.

(D) Oil in the sump/pan.

(E) Coolant before the thermostat, for liquid-cooled engines.
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(8) Linearity verification is required for the following pressure measurements:

(i) The following pressure measurements always require linearity verification:

(A) Air intake restriction.

(B) Exhaust back pressure as required in § 1065.130(h).

(C) Barometer.

(D) CVS inlet gage pressure where the raw exhaust enters the tunnel.

(E) Sample dryer, for gaseous sampling systems that use either osmotic-membrane or 

thermal chillers to dry samples. For your testing, if you choose to use a low alarm 

pressure setpoint for the sample dryer pressure as a constant value in determining the 

amount of water removed from the emission sample, you may use good engineering 

judgment to verify the accuracy of the low alarm pressure setpoint instead of linearity 

verification on the sample dryer pressure. To verify that the trip point value is no more 

than 4.0 kPa above the reference value at the trip point, we recommend that you input a 

reference pressure signal above the alarm trip point and decrease this signal until the low 

alarm trips.

(ii) Linearity verification is required for the following pressure measurements if these 

pressure measurements are specified by the engine manufacturer:

(A) The test cell’s charge air cooler and interconnecting pipe pressure drop, for turbocharged engines tested with a laboratory heat exchanger that simulates an installed charge 

air cooler.

(B) Fuel outlet.

TABLE 1 OF § 1065.307–MEASUREMENT SYSTEMS THAT REQUIRE LINEARITY 

VERIFICATION

Measurement system Quantity Linearity criteria

| xmin(a1-1)+a0| a1 SEE r

2

Speed fn ≤ 0.05 % ∙ fnmax 0.98-1.02 ≤ 2 % ∙

nmax f ≥ 0.990

Torque T ≤ 1 % ∙ Tmax 0.98-1.02 ≤ 2 % ∙ Tmax ≥ 0.990

Electrical power P ≤ 1 % ∙ Pmax 0.98-1.02 ≤ 2 % ∙ Pmax ≥ 0.990

Current I ≤ 1 % ∙ max I 0.98-1.02 ≤ 2 % ∙ max I ≥ 0.990

Voltage U ≤ 1 % ∙ U max 0.98-1.02 ≤ 2 % ∙ U max ≥ 0.990

Fuel flow rate m ≤ 1 % ∙ mmax  0.98-1.02 ≤ 2 % ∙ mmax  ≥ 0.990

Intake-air

flow rate1 n ≤ 1 % ∙ max n 0.98-1.02 ≤ 2 % ∙ max n ≥ 0.990

Dilution air

flow rate1 n ≤ 1 % ∙ max n 0.98-1.02 ≤ 2 % ∙ max n ≥ 0.990

Diluted exhaust

flow rate1 n ≤ 1 % ∙ max n 0.98-1.02 ≤ 2 % ∙ max n ≥ 0.990

Raw exhaust

flow rate1 n ≤ 1 % ∙ max n 0.98-1.02 ≤ 2 % ∙ max n ≥ 0.990

Batch sampler

flow rates1 n ≤ 1 % ∙ max n 0.98-1.02 ≤ 2 % ∙ max n ≥ 0.990

Gas dividers x/xspan ≤ 0.5 % ∙ xmax/xspan 0.98-1.02 ≤ 2 % ∙ xmax/xspan ≥ 0.990

Gas analyzers for 

laboratory testing x ≤ 0.5 % ∙ max x 0.99-1.01 ≤ 1 % ∙ max x ≥ 0.998

Gas analyzers for 

field testing x ≤ 1 % ∙ max x 0.99-1.01 ≤ 1 % ∙ max x ≥ 0.998

PM balance m ≤ 1 % ∙ mmax 0.99-1.01 ≤ 1 % ∙ mmax ≥ 0.998
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Pressures p ≤ 1 % ∙ max p 0.99-1.01 ≤ 1 % ∙ max p ≥ 0.998

Dewpoint for intake 

air, PM-stabilization 

and balance 

environments

Tdew ≤ 0.5 % ∙ Tdewmax 0.99-1.01 ≤ 0.5 % ∙ Tdewmax ≥ 0.998

Other dewpoint 

measurements Tdew ≤ 1 % ∙ Tdewmax 0.99-1.01 ≤ 1 % ∙ Tdewmax ≥ 0.998

Analog-to-digital 

conversion of 

temperature signals

T ≤ 1 % ∙ Tmax 0.99-1.01 ≤ 1 % ∙ Tmax ≥ 0.998

1

For flow meters that determine volumetric flow rate, Vstd , you may substitute Vstd for n as the quantity and 

substitute Vstdmax



for max n .

272. Section 1065.308 is amended by revising paragraph (d)(2) and adding paragraph 

(g) to read as follows:

§ 1065.308 Continuous gas analyzer system-response and updating-recording 

verification—for gas analyzers not continuously compensated for other gas species.

* * * * *

(d) * * *

(2) Equipment setup. We recommend using minimal lengths of gas transfer lines 

between all connections and fast-acting three-way valves (2 inlets, 1 outlet) to control the 

flow of zero and blended span gases to the sample system’s probe inlet or a tee near the 

outlet of the probe. If you inject the gas at a tee near the outlet of the probe, you may

correct the transformation time, t50, for an estimate of the transport time from the probe 

inlet to the tee. Normally the gas flow rate is higher than the sample flow rate and the 

excess is overflowed out the inlet of the probe. If the gas flow rate is lower than the 

sample flow rate, the gas concentrations must be adjusted to account for the dilution from 

ambient air drawn into the probe. We recommend you use the final, stabilized analyzer 

reading as the final gas concentration. Select span gases for the species being measured. 

You may use binary or multi-gas span gases. You may use a gas blending or mixing 

device to blend span gases. A gas blending or mixing device is recommended when 

blending span gases diluted in N2 with span gases diluted in air. You may use a multi-gas 

span gas, such as NO-CO-CO2-C3H8-CH4, to verify multiple analyzers at the same time. 

If you use standard binary span gases, you must run separate response tests for each 

analyzer. In designing your experimental setup, avoid pressure pulsations due to 

stopping the flow through the gas-blending device. The change in gas concentration must 

be at least 20 % of the analyzer’s range.

* * * * *

(g) Optional procedure. Instead of using a three-way valve to switch between zero and 

span gases, you may use a fast-acting two-way valve to switch sampling between ambient 

air and span gas at the probe inlet. For this alternate procedure, the following provisions 

apply:

(1) If your probe is sampling from a continuously flowing gas stream (e.g., a CVS 

tunnel), you may adjust the span gas flow rate to be different than the sample flow rate.

(2) If your probe is sampling from a gas stream that is not continuously flowing (e.g., a 

raw exhaust stack), you must adjust the span gas flow rate to be less than the sample flow 
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rate so ambient air is always being drawn into the probe inlet. This avoids errors 

associated with overflowing span gas out of the probe inlet and drawing it back in when 

sampling ambient air.

(3) When sampling ambient air or ambient air mixed with span gas, all the analyzer 

readings must be stable within ±0.5 % of the target gas concentration step size. If any 

analyzer reading is outside the specified range, you must resolve the problem and verify

that all the analyzer readings meet this specification.

(4) For oxygen analyzers, you may use purified N2 as the zero gas and ambient air (plus 

purified N2 if needed) as the reference gas. Perform the verification with seven repeat 

measurements that each consist of stabilizing with purified N2, switching to ambient air 

and observing the analyzer’s rise and stabilized reading, followed by switching back to 

purified N2 and observing the analyzer’s fall and stabilized reading.

273. Section 1065.309 is amended by revising paragraphs (a) and (d)(2) and adding 

paragraphs (g) and (h) to read as follows:

§ 1065.309 Continuous gas analyzer system-response and updating-recording 

verification—for gas analyzers continuously compensated for other gas species.

(a) Scope and frequency. This section describes a verification procedure for system 

response and updating-recording frequency for continuous gas analyzers that output a 

single gas species mole fraction (i.e., concentration) based on a continuous combination 

of multiple gas species measured with multiple detectors (i.e., gas analyzers continuously

compensated for other gas species). See § 1065.308 for verification procedures that 

apply to continuous gas analyzers that are not continuously compensated for other gas 

species or that use only one detector for gaseous species. Perform this verification to 

determine the system response of the continuous gas analyzer and its sampling system. 

This verification is required for continuous gas analyzers used for transient or rampedmodal testing. You need not perform this verification for batch gas analyzers or for 

continuous gas analyzers that are used only for discrete-mode testing. For this check we 

consider water vapor a gaseous constituent. This verification does not apply to any 

processing of individual analyzer signals that are time-aligned to their t50 times and were 

verified according to § 1065.308. For example, this verification does not apply to 

correction for water removed from the sample done in post-processing according to § 

1065.659 (40 CFR 1066.620 for vehicle testing) and it does not apply to NMHC 

determination from THC and CH4 according to § 1065.660. Perform this verification 

after initial installation (i.e., test cell commissioning) and after any modifications to the 

system that would change the system response.

* * * * *

(d) * * *

(2) Equipment setup. We recommend using minimal lengths of gas transfer lines 

between all connections and fast-acting three-way valves (2 inlets, 1 outlet) to control the 

flow of zero and blended span gases to the sample system’s probe inlet or a tee near the 

outlet of the probe. If you inject the gas at a tee near the outlet of the probe, you may

correct the transformation time, t50, for an estimate of the transport time from the probe 

inlet to the tee. Normally the gas flow rate is higher than the sample flow rate and the 
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excess is overflowed out the inlet of the probe. If the gas flow rate is lower than the 

sample flow rate, the gas concentrations must be adjusted to account for the dilution from 

ambient air drawn into the probe. We recommend you use the final, stabilized analyzer 

reading as the final gas concentration. Select span gases for the species being 

continuously combined, other than H2O. Select concentrations of compensating species 

that will yield concentrations of these species at the analyzer inlet that covers the range of 

concentrations expected during testing. You may use binary or multi-gas span gases. 

You may use a gas blending or mixing device to blend span gases. A gas blending or 

mixing device is recommended when blending span gases diluted in N2 with span gases 

diluted in air. You may use a multi-gas span gas, such as NO-CO-CO2-C3H8-CH4, to 

verify multiple analyzers at the same time. In designing your experimental setup, avoid 

pressure pulsations due to stopping the flow through the gas blending device. The 

change in gas concentration must be at least 20 % of the analyzer’s range. If H2O 

correction is applicable, then span gases must be humidified before entering the analyzer; 

however, you may not humidify NO2 span gas by passing it through a sealed 

humidification vessel that contains water. You must humidify NO2 span gas with another 

moist gas stream. We recommend humidifying your NO-CO-CO2-C3H8-CH4, balance N2

blended gas by flowing the gas mixture through a sealed vessel that humidifies the gas by 

bubbling it through distilled water and then mixing the gas with dry NO2 gas, balance 

purified air. If your system does not use a sample dryer to remove water from the sample 

gas, you must humidify your span gas to the highest sample H2O content that you 

estimate during emission sampling. If your system uses a sample dryer during testing, it 

must pass the sample dryer verification check in § 1065.342, and you must humidify your 

span gas to an H2O content greater than or equal to the level determined in § 

1065.145(e)(2). If you are humidifying span gases without NO2, use good engineering 

judgment to ensure that the wall temperatures in the transfer lines, fittings, and valves 

from the humidifying system to the probe are above the dewpoint required for the target 

H2O content. If you are humidifying span gases with NO2, use good engineering 

judgment to ensure that there is no condensation in the transfer lines, fittings, or valves 

from the point where humidified gas is mixed with NO2 span gas to the probe. We 

recommend that you design your setup so that the wall temperatures in the transfer lines, 

fittings, and valves from the humidifying system to the probe are at least 5 oC above the 

local sample gas dewpoint. Operate the measurement and sample handling system as you 

do for emission testing. Make no modifications to the sample handling system to reduce 

the risk of condensation. Flow humidified gas through the sampling system before this 

check to allow stabilization of the measurement system’s sampling handling system to 

occur, as it would for an emission test.

* * * * *

(g) Optional procedure. Follow the optional procedures in § 1065.308(g), noting that you 

may use compensating gases mixed with ambient air for oxygen analyzers.

(h) Analyzers with H2O compensation sampling downstream of a sample dryer. You 

may omit humidifying the span gas as described in this paragraph (h). If an analyzer 

compensates only for H2O, you may apply the requirements of § 1065.308 instead of the 
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requirements of this section. You may omit humidifying the span gas if you meet the 

following conditions:

(1) The analyzer is located downstream of a sample dryer.

(2) The maximum value for H2O mole fraction downstream of the dryer must be less than 

or equal to 0.010. Verify this during each sample dryer verification according to § 

1065.342.

274. Section 1065.310 is revised to read as follows:

§ 1065.310 Torque calibration.

(a) Scope and frequency. Calibrate all torque-measurement systems including 

dynamometer torque measurement transducers and systems upon initial installation and 

after major maintenance. Use good engineering judgment to repeat the calibration. 

Follow the torque transducer manufacturer’s instructions for linearizing your torque 

sensor’s output. We recommend that you calibrate the torque-measurement system with 

a reference force and a lever arm.

(b) Recommended procedure to quantify lever-arm length. Quantify the lever-arm 

length, NIST-traceable within 0.5 % uncertainty. The lever arm’s length must be 

measured from the centerline of the dynamometer to the point at which the reference 

force is measured. The lever arm must be perpendicular to gravity (i.e., horizontal), and 

it must be perpendicular to the dynamometer’s rotational axis. Balance the lever arm’s 

torque or quantify its net hanging torque, NIST-traceable within 1 % uncertainty, and 

account for it as part of the reference torque.

(c) Recommended procedure to quantify reference force. We recommend dead-weight 

calibration, but you may use either of the following procedures to quantify the reference 

force, NIST-traceable within 0.5 % uncertainty.

(1) Dead-weight calibration. This technique applies a known force by hanging known 

weights at a known distance along a lever arm. Make sure the weights’ lever arm is 

perpendicular to gravity (i.e., horizontal) and perpendicular to the dynamometer’s 

rotational axis. Apply at least six calibration-weight combinations for each applicable 

torque-measuring range, spacing the weight quantities about equally over the range. 

Oscillate or rotate the dynamometer during calibration to reduce frictional static 

hysteresis. Determine each weight’s reference force by multiplying its NIST-traceable 

mass by the local acceleration of Earth’s gravity, as described in § 1065.630. Calculate 

the reference torque as the weights’ reference force multiplied by the lever arm reference 

length.

(2) Strain gage, load transducer, or proving ring calibration. This technique applies force 

either by hanging weights on a lever arm (these weights and their lever arm length are not 

used as part of the reference torque determination) or by operating the dynamometer at 

different torques. Apply at least six force combinations for each applicable torquemeasuring range, spacing the force quantities about equally over the range. Oscillate or 

rotate the dynamometer during calibration to reduce frictional static hysteresis. In this 

case, the reference torque is determined by multiplying the force output from the 

reference meter (such as a strain gage, load transducer, or proving ring) by its effective 

lever-arm length, which you measure from the point where the force measurement is 
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made to the dynamometer’s rotational axis. Make sure you measure this length 

perpendicular to the reference meter’s measurement axis and perpendicular to the 

dynamometer’s rotational axis.

275. Section 1065.315 is amended by revising paragraph (a)(2) to read as follows:

§ 1065.315 Pressure, temperature, and dewpoint calibration.

(a) * * *

(2) Temperature. We recommend digital dry-block or stirred-liquid temperature 

calibrators, with data logging capabilities to minimize transcription errors. We 

recommend using calibration reference quantities that are NIST-traceable within 0.5 % 

uncertainty. You may perform linearity verification for temperature measurement 

systems with thermocouples, RTDs, and thermistors by removing the sensor from the 

system and using a simulator in its place. Use a NIST-traceable simulator that is 

independently calibrated and, as appropriate, cold-junction compensated. The simulator 

uncertainty scaled to absolute temperature must be less than 0.5 % of Tmax. If you use 

this option, you must use sensors that the supplier states are accurate to better than 0.5 % 

of Tmax compared with their standard calibration curve.

* * * * *

276. Section 1065.341 is amended by revising the section heading and paragraphs (a) 

introductory text, (d) introductory text, and (f)(3) to read as follows:

§ 1065.341 CVS, PFD, and batch sampler verification (propane check).

(a) A propane check serves as a CVS verification to determine if there is a discrepancy in 

measured values of diluted exhaust flow. You may use the same procedure to verify

PFDs and batch samplers. For purposes of PFD and batch sampler verification, read the 

term CVS to mean PFD or batch sampler as appropriate. A propane check also serves as 

a batch-sampler verification to determine if there is a discrepancy in a batch sampling 

system that extracts a sample from a CVS, as described in paragraph (g) of this section. 

Using good engineering judgment and safe practices, this check may be performed using 

a gas other than propane, such as CO2 or CO. A failed propane check might indicate one 

or more problems that may require corrective action, as follows:

* * * * *

(d) If you performed the vacuum-side leak verification of the HC sampling system as 

described in paragraph (c)(8) of this section, you may use the HC contamination 

procedure in § 1065.520(f) to verify HC contamination. Otherwise, zero, span, and verify

contamination of the HC sampling system, as follows:

* * * * *

(f) * * *

(3) Calculate total C3H8 mass based on your CVS and HC data as described in § 

1065.650 (40 CFR 1066.605 for vehicle testing) and § 1065.660, using the molar mass of 

C3H8, MC3H8, instead the effective molar mass of HC, MHC.

* * * * *
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277. Section 1065.350 is amended by revising paragraphs (d) and (e)(1) to read as 

follows:

§ 1065.350 H2O interference verification for CO2 NDIR analyzers.

* * * * *

(d) Procedure. Perform the interference verification as follows:

(1) Start, operate, zero, and span the CO2 NDIR analyzer as you would before an 

emission test. If the sample is passed through a dryer during emission testing, you may 

run this verification test with the dryer if it meets the requirements of § 1065.342. 

Operate the dryer at the same conditions as you will for an emission test. You may also 

run this verification test without the sample dryer.

(2) Create a humidified test gas by bubbling zero gas that meets the specifications in § 

1065.750 through distilled H2O in a sealed vessel. If the sample is not passed through a 

dryer during emission testing, control the vessel temperature to generate an H2O level at 

least as high as the maximum expected during emission testing. If the sample is passed 

through a dryer during emission testing, control the vessel temperature to generate an 

H2O level at least as high as the level determined in § 1065.145(e)(2) for that dryer.

(3) Introduce the humidified test gas into the sample system. You may introduce it

downstream of any sample dryer, if one is used during testing.

(4) If the sample is not passed through a dryer during this verification test, measure the 

H2O mole fraction, xH2O, of the humidified test gas, as close as possible to the inlet of the 

analyzer. For example, measure dewpoint, Tdew, and absolute pressure, ptotal, to calculate 

xH2O. Verify that the H2O content meets the requirement in paragraph (d)(2) of this 

section. If the sample is passed through a dryer during this verification test, you must 

verify that the H2O content of the humidified test gas downstream of the vessel meets the 

requirement in paragraph (d)(2) of this section based on either direct measurement of the 

H2O content (e.g., dewpoint and pressure) or an estimate based on the vessel pressure and 

temperature. Use good engineering judgment to estimate the H2O content. For example, 

you may use previous direct measurements of H2O content to verify the vessel’s level of 

saturation.

(5) If a sample dryer is not used in this verification test, use good engineering judgment 

to prevent condensation in the transfer lines, fittings, or valves from the point where xH2O

is measured to the analyzer. We recommend that you design your system so the wall 

temperatures in the transfer lines, fittings, and valves from the point where xH2O is 

measured to the analyzer are at least 5 oC above the local sample gas dewpoint.

(6) Allow time for the analyzer response to stabilize. Stabilization time may include time 

to purge the transfer line and to account for analyzer response.

(7) While the analyzer measures the sample’s concentration, record 30 seconds of 

sampled data. Calculate the arithmetic mean of this data. The analyzer meets the 

interference verification if this value is within (0.0 ±0.4) mmol/mol.

(e) * * *

(1) You may omit this verification if you can show by engineering analysis that for your 

CO2 sampling system and your emission-calculation procedures, the H2O interference for 

your CO2 NDIR analyzer always affects your brake-specific emission results within 0.5 
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% of each of the applicable standards. This specification also applies for vehicle testing, 

except that it relates to emission results in g/mile or g/kilometer.

* * * * *

278. Section 1065.355 is amended by revising paragraphs (d)(2) and (d)(4) to read as 

follows:

§ 1065.355 H2O and CO2 interference verification for CO NDIR analyzers.

* * * * *

(d) * * *

(2) Create a humidified CO2 test gas by bubbling a CO2 span gas that meets the 

specifications in § 1065.750 through distilled H2O in a sealed vessel. If the sample is not 

passed through a dryer during emission testing, control the vessel temperature to generate 

an H2O level at least as high as the maximum expected during emission testing. If the 

sample is passed through a dryer during emission testing, control the vessel temperature 

to generate an H2O level at least as high as the level determined in § 1065.145(e)(2) for 

that dryer. Use a CO2 span gas concentration at least as high as the maximum expected 

during testing.

* * * * *

(4) If the sample is not passed through a dryer during this verification test, measure the 

H2O mole fraction, xH2O, of the humidified CO2 test gas as close as possible to the inlet of 

the analyzer. For example, measure dewpoint, Tdew, and absolute pressure, ptotal, to 

calculate xH2O. Verify that the H2O content meets the requirement in paragraph (d)(2) of 

this section. If the sample is passed through a dryer during this verification test, you must 

verify that the H2O content of the humidified test gas downstream of the vessel meets the 

requirement in paragraph (d)(2) of this section based on either direct measurement of the 

H2O content (e.g., dewpoint and pressure) or an estimate based on the vessel pressure and 

temperature. Use good engineering judgment to estimate the H2O content. For example, 

you may use previous direct measurements of H2O content to verify the vessel’s level of 

saturation.

* * * * *

279. Section 1065.360 is amended by revising paragraphs (a)(3), (b), (d), and (e) to 

read as follows:

§ 1065.360 FID optimization and verification.

(a) * * *

(3) Verify the CH4 response within 185 days before testing as described in paragraph (e) 

of this section.

(b) Calibration. Use good engineering judgment to develop a calibration procedure, such 

as one based on the FID-analyzer manufacturer’s instructions and recommended 

frequency for calibrating the FID. Alternately, you may remove system components for 

off-site calibration. For a FID that measures THC, calibrate using C3H8 calibration gases 

that meet the specifications of § 1065.750. For a FID that measures CH4, calibrate using 

CH4 calibration gases that meet the specifications of § 1065.750. We recommend FID 

analyzer zero and span gases that contain approximately the flow-weighted mean 
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concentration of O2 expected during testing. If you use a FID to measure CH4

downstream of a nonmethane cutter, you may calibrate that FID using CH4 calibration 

gases with the cutter. Regardless of the calibration gas composition, calibrate on a 

carbon number basis of one (C1). For example, if you use a C3H8 span gas of 

concentration 200 mol/mol, span the FID to respond with a value of 600 mol/mol. As 

another example, if you use a CH4 span gas with a concentration of 200 mol/mol, span 

the FID to respond with a value of 200 mol/mol.

* * * * *

(d) THC FID CH4 response factor determination. This procedure is only for FID 

analyzers that measure THC. Since FID analyzers generally have a different response to 

CH4 versus C3H8, determine each THC-FID analyzer’s CH4 response factor, RFCH4[THCFID], after FID optimization. Use the most recent RFCH4[THC-FID] measured according to 

this section in the calculations for HC determination described in § 1065.660 to 

compensate for CH4 response. Determine RFCH4[THC-FID] as follows, noting that you do 

not determine RFCH4[THC-FID] for FIDs that are calibrated and spanned using CH4 with a 

nonmethane cutter:

(1) Select a C3H8 span gas concentration that you use to span your analyzers before 

emission testing. Use only span gases that meet the specifications of § 1065.750. Record 

the C3H8 concentration of the gas.

(2) Select a CH4 span gas concentration that you use to span your analyzers before 

emission testing. Use only span gases that meet the specifications of § 1065.750. Record 

the CH4 concentration of the gas.

(3) Start and operate the FID analyzer according to the manufacturer’s instructions.

(4) Confirm that the FID analyzer has been calibrated using C3H8. Calibrate on a carbon 

number basis of one (C1). For example, if you use a C3H8 span gas of concentration 200 

mol/mol, span the FID to respond with a value of 600 mol/mol.

(5) Zero the FID with a zero gas that you use for emission testing.

(6) Span the FID with the C3H8 span gas that you selected under paragraph (d)(1) of this 

section.

(7) Introduce at the sample port of the FID analyzer, the CH4 span gas that you selected 

under paragraph (d)(2) of this section.

(8) Allow time for the analyzer response to stabilize. Stabilization time may include time 

to purge the analyzer and to account for its response.

(9) While the analyzer measures the CH4 concentration, record 30 seconds of sampled 

data. Calculate the arithmetic mean of these values. 

(10) For analyzers with multiple ranges, you need to perform the procedure in this 

paragraph (d) only on a single range. 

(11) Divide the mean measured concentration by the recorded span concentration of the 

CH4 calibration gas. The result is the FID analyzer’s response factor for CH4, RFCH4[THCFID].

(e) THC FID CH4 response verification. This procedure is only for FID analyzers that 

measure THC. Verify RFCH4[THC-FID] as follows:

(1) Perform a CH4 response factor determination as described in paragraph (d) of this 

section. If the resulting value of RFCH4[THC-FID] is within 5 % of its most recent 
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previously determined value, the THC FID passes the CH4 response verification. For 

example, if the most recent previous value for RFCH4[THC-FID] was 1.05 and it increased by 

0.05 to become 1.10 or it decreased by 0.05 to become 1.00, either case would be 

acceptable because 4.8 % is less than 5 %.

(2) If RFCH4[THC-FID] is not within the tolerance specified in paragraph (e)(1) of this 

section, use good engineering judgment to verify that the flow rates and/or pressures of 

FID fuel, burner air, and sample are at their most recent previously recorded values, as 

determined in paragraph (c) of this section. You may adjust these flow rates as 

necessary. Then determine the RFCH4[THC-FID] as described in paragraph (d) of this section 

and verify that it is within the tolerance specified in this paragraph (e).

(3) If RFCH4[THC-FID] is not within the tolerance specified in this paragraph (e), re-optimize 

the FID response as described in paragraph (c) of this section.

(4) Determine a new RFCH4[THC-FID] as described in paragraph (d) of this section. Use this 

new value of RFCH4[THC-FID] in the calculations for HC determination, as described in § 

1065.660.

(5) For analyzers with multiple ranges, you need to perform the procedure in this 

paragraph (e) only on a single range.

280. Section 1065.362 is amended by adding paragraph (d)(15) to read as follows:

§ 1065.362 Non-stoichiometric raw exhaust FID O2 interference verification.

* * * * *

(d) * *

(15) For analyzers with multiple ranges, you need to perform the procedure in this 

paragraph (d) only on a single range. 

281. Section 1065.365 is amended by revising paragraphs (a), (b), (d)(1), (e)(1), (f) 

introductory text, and (f)(1) to read as follows:

§ 1065.365 Nonmethane cutter penetration fractions.

(a) Scope and frequency. If you use a FID analyzer and a nonmethane cutter (NMC) to 

measure methane (CH4), determine the nonmethane cutter’s penetration fractions of CH4, 

PFCH4, and ethane, PFC2H6. As detailed in this section, these penetration fractions may be 

determined as a combination of NMC penetration fractions and FID analyzer response 

factors, depending on your particular NMC and FID analyzer configuration. Perform this 

verification after installing the nonmethane cutter. Repeat this verification within 185 

days of testing to verify that the catalytic activity of the cutter has not deteriorated. Note 

that because nonmethane cutters can deteriorate rapidly and without warning if they are 

operated outside of certain ranges of gas concentrations and outside of certain 

temperature ranges, good engineering judgment may dictate that you determine a 

nonmethane cutter’s penetration fractions more frequently.

(b) Measurement principles. A nonmethane cutter is a heated catalyst that removes 

nonmethane hydrocarbons from an exhaust sample stream before the FID analyzer 

measures the remaining hydrocarbon concentration. An ideal nonmethane cutter would 

have a CH4 penetration fraction, PFCH4, of 1.000, and the penetration fraction for all other 

nonmethane hydrocarbons would be 0.000, as represented by PFC2H6. The emission 
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calculations in § 1065.660 use the measured values from this verification to account for 

less than ideal NMC performance.

* * * * *

(d) * * *

(1) Select CH4 and C2H6 analytical gas mixtures and ensure that both mixtures meet the 

specifications of § 1065.750. Select a CH4 concentration that you would use for spanning 

the FID during emission testing and select a C2H6 concentration that is typical of the peak 

NMHC concentration expected at the hydrocarbon standard or equal to the THC 

analyzer’s span value. For CH4 analyzers with multiple ranges, perform this procedure 

on the highest range used for emission testing.

* * * * *

(e) * * *

(1) Select CH4 and C2H6 analytical gas mixtures and ensure that both mixtures meet the 

specifications of § 1065.750. Select a CH4 concentration that you would use for spanning 

the FID during emission testing and select a C2H6 concentration that is typical of the peak 

NMHC concentration expected at the hydrocarbon standard and the C2H6 concentration 

typical of the peak total hydrocarbon (THC) concentration expected at the hydrocarbon 

standard or equal to the THC analyzer’s span value. For CH4 analyzers with multiple 

ranges, perform this procedure on the highest range used for emission testing.

* * * * *

(f) Procedure for a FID calibrated with CH4, bypassing the NMC. If you use a FID with 

an NMC that is calibrated with CH4, by bypassing the NMC, determine its combined 

ethane (C2H6) response factor and penetration fraction, RFPFC2H6[NMC-FID] , as well as its 

CH4 penetration fraction, PFCH4[NMC-FID], as follows:

(1) Select CH4 and C2H6 analytical gas mixtures and ensure that both mixtures meet the 

specifications of § 1065.750. Select a CH4 concentration that you would use for spanning 

the FID during emission testing and select a C2H6 concentration that is typical of the peak 

NMHC concentration expected at the hydrocarbon standard or equal to the THC 

analyzer’s span value. For CH4 analyzers with multiple ranges, perform this procedure 

on the highest range used for emission testing.

* * * * *

282. A new § 1065.369 is added to subpart D under the center header “Hydrocarbon 

Measurements” to read as follows:

§ 1065.369 H2O, CO, and CO2 interference verification for photoacoustic alcohol 

analyzers.

(a) Scope and frequency. If you measure ethanol or methanol using a photoacoustic 

analyzer, verify the amount of H2O, CO, and CO2 interference after initial analyzer 

installation and after major maintenance.

(b) Measurement principles. H2O, CO, and CO2 can positively interfere with a 

photoacoustic analyzer by causing a response similar to ethanol or methanol. If the 

photoacoustic analyzer uses compensation algorithms that utilize measurements of other 

gases to meet this interference verification, simultaneously conduct these other 
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measurements to test the compensation algorithms during the analyzer interference 

verification.

(c) System requirements. Photoacoustic analyzers must have combined interference that 

is within (0.0 ± 0.5) μmol/mol. We strongly recommend a lower interference that is 

within (0.0 ± 0.25) μmol/mol.

(d) Procedure. Perform the interference verification by following the procedure in § 

1065.375(d), comparing the results to paragraph (c) of this section.

283. Section 1065.370 is amended by revising paragraphs (d)(9) and (e)(5) to read as 

follows:

§ 1065.370 CLD CO2 and H2O quench verification.

* * * * *

(d) * * *

(9) While flowing NO and CO2 through the gas divider, stabilize the output of the gas 

divider. Determine the CO2 concentration from the gas divider output, applying gas 

property correction as necessary to ensure accurate gas division, or measure it using an 

NDIR. Record this concentration, xCO2act, and use it in the quench verification 

calculations in § 1065.675. Alternatively, you may use a simple gas blending device and 

use an NDIR to determine this CO2 concentration. If you use an NDIR, it must meet the 

requirements of this part for laboratory testing and you must span it with the CO2 span 

gas from paragraph (d)(4) of this section.

* * * * *

(e) * * *

(5) Humidify the NO span gas by bubbling it through distilled H2O in a sealed vessel. If 

the humidified NO span gas sample does not pass through a sample dryer for this 

verification test, control the vessel temperature to generate an H2O level approximately

equal to the maximum mole fraction of H2O expected during emission testing. If the 

humidified NO span gas sample does not pass through a sample dryer, the quench 

verification calculations in § 1065.675 scale the measured H2O quench to the highest 

mole fraction of H2O expected during emission testing. If the humidified NO span gas 

sample passes through a dryer for this verification test, control the vessel temperature to 

generate an H2O level at least as high as the level determined in § 1065.145(e)(2). For 

this case, the quench verification calculations in § 1065.675 do not scale the measured 

H2O quench.

* * * * *

284. Section 1065.375 is amended by revising paragraph (d) to read as follows:

§ 1065.375 Interference verification for N2O analyzers.

* * * * *

(d) Procedure. Perform the interference verification as follows:

(1) Start, operate, zero, and span the N2O analyzer as you would before an emission test. 

If the sample is passed through a dryer during emission testing, you may run this 

verification test with the dryer if it meets the requirements of § 1065.342. Operate the 
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dryer at the same conditions as you will for an emission test. You may also run this 

verification test without the sample dryer.

(2) Create a humidified test gas by bubbling a multi component span gas that incorporates 

the target interference species and meets the specifications in § 1065.750 through 

distilled H2O in a sealed vessel. If the sample is not passed through a dryer during 

emission testing, control the vessel temperature to generate an H2O level at least as high 

as the maximum expected during emission testing. If the sample is passed through a 

dryer during emission testing, control the vessel temperature to generate an H2O level at

least as high as the level determined in § 1065.145(e)(2) for that dryer. Use interference 

span gas concentrations that are at least as high as the maximum expected during testing.

(3) Introduce the humidified interference test gas into the sample system. You may

introduce it downstream of any sample dryer, if one is used during testing. 

(4) If the sample is not passed through a dryer during this verification test, measure the 

H2O mole fraction, xH2O, of the humidified interference test gas as close as possible to the 

inlet of the analyzer. For example, measure dewpoint, Tdew, and absolute pressure, ptotal, 

to calculate xH2O. Verify that the H2O content meets the requirement in paragraph (d)(2) 

of this section. If the sample is passed through a dryer during this verification test, you 

must verify that the H2O content of the humidified test gas downstream of the vessel 

meets the requirement in paragraph (d)(2) of this section based on either direct 

measurement of the H2O content (e.g., dewpoint and pressure) or an estimate based on 

the vessel pressure and temperature. Use good engineering judgment to estimate the H2O

content. For example, you may use previous direct measurements of H2O content to 

verify the vessel’s level of saturation.

(5) If a sample dryer is not used in this verification test, use good engineering judgment 

to prevent condensation in the transfer lines, fittings, or valves from the point where xH2O

is measured to the analyzer. We recommend that you design your system so that the wall

temperatures in the transfer lines, fittings, and valves from the point where xH2O is 

measured to the analyzer are at least 5 oC above the local sample gas dewpoint.

(6) Allow time for the analyzer response to stabilize. Stabilization time may include time 

to purge the transfer line and to account for analyzer response.

(7) While the analyzer measures the sample’s concentration, record its output for 30 

seconds. Calculate the arithmetic mean of this data. When performed with all the gases 

simultaneously, this is the combined interference.

(8) The analyzer meets the interference verification if the result of paragraph (d)(7) of 

this section meets the tolerance in paragraph (c) of this section.

(9) You may also run interference procedures separately for individual interference gases. 

If the interference gas levels used are higher than the maximum levels expected during 

testing, you may scale down each observed interference value (the arithmetic mean of 30 

second data described in paragraph (d)(7) of this section) by multiplying the observed 

interference by the ratio of the maximum expected concentration value to the actual value 

used during this procedure. You may run separate interference concentrations of H2O 

(down to 0.025 mol/mol H2O content) that are lower than the maximum levels expected 

during testing, but you must scale up the observed H2O interference by multiplying the 

observed interference by the ratio of the maximum expected H2O concentration value to 
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the actual value used during this procedure. The sum of the scaled interference values 

must meet the tolerance for combined interference as specified in paragraph (c) of this 

section.

285. Section 1065.376 is amended by revising paragraphs (b), (d)(2)(vi), and 

(d)(2)(viii) to read as follows:

§ 1065.376 Chiller NO2 penetration.

* * * * *

(b) Measurement principles. A chiller removes H2O, which can otherwise interfere with 

a NOx measurement. However, liquid H2O remaining in an improperly designed chiller 

can remove NO2 from the sample. If a chiller is used without an NO2-to-NO converter 

upstream, it could remove NO2 from the sample prior NOx measurement.

* * * * *

(d) * * *

(2) * * *

(vi) Next saturate the sampling system by overflowing a dewpoint generator’s output, set 

at a dewpoint of 50 C, to the gas sampling system’s probe or overflow fitting. Sample 

the dewpoint generator’s output through the sampling system and chiller for at least 10 

minutes until the chiller is expected to be removing a constant rate of H2O.

* * * * *

(viii) Correct xNOxmeas to xNOxdry based upon the residual H2O vapor that passed through 

the chiller at the chiller’s outlet temperature and pressure.

* * * * *

Subpart E—[Amended]

286. Section 1065.405 is revised to read as follows:

§ 1065.405 Test engine preparation and maintenance.

This part 1065 describes how to test engines for a variety of purposes, including 

certification testing, production-line testing, and in-use testing. Depending on which type 

of testing is being conducted, different preparation and maintenance requirements apply

for the test engine. 

(a) If you are testing an emission-data engine for certification, make sure it is built to 

represent production engines, consistent with paragraph (f) of this section. This includes 

governors that you normally install on production engines. Production engines should 

also be tested with their installed governors. If your engine is equipped with multiple 

user-selectable governor types and if the governor does not manipulate the emission 

control system (i.e., the governor only modulates an "operator demand" signal such as 

commanded fuel rate, torque, or power), choose the governor type that allows the test cell 

to most accurately follow the duty cycle. If the governor manipulates the emission 

control system, treat it as an adjustable parameter. See paragraph (b) of this section for 

guidance on setting adjustable parameters. If you do not install governors on production 

engines, simulate a governor that is representative of a governor that others will install on 

your production engines. In certain circumstances, you may incorporate test cell 
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components to simulate an in-use configuration, consistent with good engineering 

judgment. For example, §§ 1065.122 and 1065.125 allow the use of test cell components 

to represent engine cooling and intake air systems. The provisions in § 1065.110(e) also 

apply to emission-data engines for certification.

(b) We may set adjustable parameters to any value in the valid range, and you are 

responsible for controlling emissions over the full valid range. For each adjustable 

parameter, if the standard-setting part has no unique requirements and if we have not 

specified a value, use good engineering judgment to select the most common setting. If 

information on the most common setting is not available, select the setting representing 

the engine’s original shipped configuration. If information on the most common and 

original settings is not available, set the adjustable parameter in the middle of the valid 

range.

(c) Testing generally occurs only after the test engine has undergone a stabilization step 

(or in-use operation). If the engine has not already been stabilized, run the test engine, 

with all emission control systems operating, long enough to stabilize emission levels. 

Note that you must generally use the same stabilization procedures for emission-data 

engines for which you apply the same deterioration factors so low-hour emission-data 

engines are consistent with the low-hour engine used to develop the deterioration factor.

(1) Unless otherwise specified in the standard-setting part, you may consider emission 

levels stable without measurement after 50 h of operation. If the engine needs less 

operation to stabilize emission levels, record your reasons and the methods for doing this, 

and give us these records if we ask for them. If the engine will be tested for certification 

as a low-hour engine, see the standard-setting part for limits on testing engines to 

establish low-hour emission levels.

(2) You may stabilize emissions from a catalytic exhaust aftertreatment device by 

operating it on a different engine, consistent with good engineering judgment. Note that 

good engineering judgment requires that you consider both the purpose of the test and 

how your stabilization method will affect the development and application of 

deterioration factors. For example, this method of stabilization is generally not 

appropriate for production engines. We may also allow you to stabilize emissions from a 

catalytic exhaust aftertreatment device by operating it on an engine-exhaust simulator.

(d) Record any maintenance, modifications, parts changes, diagnostic or emissions 

testing and document the need for each event. You must provide this information if we 

request it.

(e) For accumulating operating hours on your test engines, select engine operation that 

represents normal in-use operation for the engine family.

(f) If your engine will be used in a vehicle equipped with a canister for storing 

evaporative hydrocarbons for eventual combustion in the engine and the test sequence 

involves a cold-start or hot-start duty cycle, attach a canister to the engine before running 

an emission test. You may omit using an evaporative canister for any hot-stabilized duty

cycles. You may request to omit using an evaporative canister during testing if you can 

show that it would not affect your ability to show compliance with the applicable 

emission standards. You may operate the engine without an installed canister for service 
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accumulation. Prior to an emission test, use the following steps to precondition a canister 

and attach it to your engine:

(1) Use a canister and plumbing arrangement that represents the in-use configuration of 

the largest capacity canister in all expected applications.

(2) Precondition the canister as described in 40 CFR 86.132-96(j).

(3) Connect the canister’s purge port to the engine.

(4) Plug the canister port that is normally connected to the fuel tank.

(g) This paragraph (g) defines the components that are considered to be part of the engine 

for laboratory testing. See § 1065.110 for provisions related to system boundaries with 

respect to work inputs and outputs. 

(1) This paragraph (g)(1) describes certain criteria for considering a component to be part 

of the test engine. The criteria are intended to apply broadly, such that a component 

would generally be considered part of the engine in cases of uncertainty. Except as 

specified in paragraph (g)(2) of this section, an engine-related component meeting both 

the following criteria is considered to be part of the test engine for purposes of testing and 

for stabilizing emission levels, preconditioning, and measuring emission levels:

(i) The component directly affects the functioning of the engine, is related to controlling 

emissions, or transmits engine power. This would include engine cooling systems, 

engine controls, and transmissions.

(ii) The component is covered by the applicable certificate of conformity. For example, 

this criterion would typically exclude radiators not described in an application for 

certification.

(2) This paragraph (g)(2) applies for engine-related components that meet the criteria of 

paragraph (g)(1) of this section, but that are part of the laboratory setup or are used for 

other engines. Such components are considered to be part of the test engine for 

preconditioning, but not for engine stabilization. For example, if you test your engines 

using the same laboratory exhaust tubing for all tests, there would be no restrictions on 

the number of test hours that could be accumulated with the tubing, but it would need to 

be preconditioned separately for each engine.

287. Section 1065.410 is amended by revising paragraph (c) to read as follows:

§ 1065.410 Maintenance limits for stabilized test engines.

* * * * *

(c) If you inspect an engine, keep a record of the inspection and update your application 

to document any changes that result. You may use any kind of equipment, instrument, or 

tool to identify bad engine components or perform maintenance if it is available at 

dealerships and other service outlets.

* * * * *

Subpart F—[Amended]

288. Section 1065.501 is revised to read as follows:

§ 1065.501 Overview.
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(a) Use the procedures detailed in this subpart to measure engine emissions over a 

specified duty cycle. Refer to subpart J of this part for field test procedures that describe 

how to measure emissions during in-use engine operation. This section describes how to:

(1) Map your engine, if applicable, by recording specified speed and torque data, as 

measured from the engine’s primary output shaft.

(2) Transform normalized duty cycles into reference duty cycles for your engine by using 

an engine map.

(3) Prepare your engine, equipment, and measurement instruments for an emission test.

(4) Perform pre-test procedures to verify proper operation of certain equipment and 

analyzers.

(5) Record pre-test data.

(6) Start or restart the engine and sampling systems.

(7) Sample emissions throughout the duty cycle.

(8) Record post-test data.

(9) Perform post-test procedures to verify proper operation of certain equipment and 

analyzers.

(10) Weigh PM samples.

(b) Unless we specify otherwise, you may control the regeneration timing of infrequently 

regenerated aftertreatment devices such as diesel particulate filters using good 

engineering judgment. You may control the regeneration timing using a sequence of 

engine operating conditions or you may initiate regeneration with an external 

regeneration switch or other command. This provision also allows you to ensure that a 

regeneration event does not occur during an emission test.

(c) An emission test generally consists of measuring emissions and other parameters 

while an engine follows one or more duty cycles that are specified in the standard-setting 

part. There are two general types of duty cycles:

(1) Transient cycles. Transient duty cycles are typically specified in the standard-setting 

part as a second-by-second sequence of speed commands and normalized torque (or 

power) commands. Operate an engine over a transient cycle such that the speed and 

torque of the engine’s primary output shaft follows the target values. Proportionally

sample emissions and other parameters and use the calculations in subpart G of this part 

to calculate emissions. Start a transient test according to the standard-setting part, as 

follows:

(i) A cold-start transient cycle where you start to measure emissions just before starting 

an engine that has not been warmed up.

(ii) A hot-start transient cycle where you start to measure emissions just before starting a 

warmed-up engine.

(iii) A hot running transient cycle where you start to measure emissions after an engine is 

started, warmed up, and running.

(2) Steady-state cycles. Steady-state duty cycles are typically specified in the standardsetting part as a list of discrete operating points (modes or notches), where each operating 

point has one value of a normalized speed command and one value of a normalized 

torque (or power) command. Ramped-modal cycles for steady-state testing also list test 

times for each mode and transition times between modes where speed and torque are 
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linearly ramped between modes, even for cycles with % power. Start a steady-state cycle 

as a hot running test, where you start to measure emissions after an engine is started, 

warmed up and running. Run a steady-state duty cycle as a discrete-mode cycle or a 

ramped-modal cycle, as follows:

(i) Discrete-mode cycles. Before emission sampling, stabilize an engine at the first 

discrete mode of the duty cycle specified in the standard-setting part. Sample emissions

and other parameters for that mode in the same manner as a transient cycle, with the 

exception that reference speed and torque values are constant. Record data for that mode, 

transition to the next mode, and then stabilize the engine at the next mode. Continue to 

sample each mode discretely as a separate test interval and calculate composite brakespecific emission results according to § 1065.650(g)(2).

(A) Use good engineering judgment to determine the time required to stabilize the 

engine. You may make this determination before starting the test based on prior 

experience, or you may make this determination in real time based an automated stability

criteria. If needed, you may continue to operate the engine after reaching stability to get 

laboratory equipment ready for sampling.

(B) Collect PM on separate PM sample media for each mode.

(C) The minimum sample time is 60 seconds. We recommend that you sample both 

gaseous and PM emissions over the same test interval. If you sample gaseous and PM 

emissions over different test intervals, there must be no change in engine operation 

between the two test intervals. These two test intervals may completely or partially 

overlap, they may run consecutively, or they may be separated in time.

(ii) Ramped-modal cycles. Perform ramped-modal cycles similar to the way you would 

perform transient cycles, except that ramped-modal cycles involve mostly steady-state 

engine operation. Generate a ramped-modal duty cycle as a sequence of second-bysecond (1 Hz) reference speed and torque points. Run the ramped-modal duty cycle in 

the same manner as a transient cycle and use the 1 Hz reference speed and torque values 

to validate the cycle, even for cycles with % power. Proportionally sample emissions and 

other parameters during the cycle and use the calculations in subpart G of this part to 

calculate emissions. 

(d) Other subparts in this part identify how to select and prepare an engine for testing 

(subpart E), how to perform the required engine service accumulation (subpart E), and 

how to calculate emission results (subpart G).

(e) Subpart J of this part describes how to perform field testing.

289. Section 1065.510 is amended by revising paragraph (d)(5)(ii) to read as follows:

§ 1065.510 Engine mapping.

* * * * *

(d) * * *

(5) * * *

(ii) For any constant-speed engine, you may perform an engine map with a continuous 

torque sweep by continuing to record the mean feedback speed and torque at 1 Hz or 

more frequently. Use the dynamometer to increase torque. Increase the reference torque 

at a constant rate from no-load to the endpoint torque as defined in paragraph (d)(5)(i) of 
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this section. You may continue mapping at higher torque setpoints. Unless the standardsetting part specifies otherwise, target a torque sweep rate equal to the manufacturerdeclared test torque (or a torque derived from your published power level if the declared 

test torque is not known) divided by 180 seconds. Stop recording after you complete the 

sweep. Verify that the average torque sweep rate over the entire map is within ±7 % of 

the target torque sweep rate. Use linear interpolation to determine intermediate values 

from this series of mean feedback speed and torque values. Use this series of mean 

feedback speeds and torques to generate the power map as described in paragraph (e) of 

this section.

* * * * *

290. Section 1065.512 is amended by revising paragraph (b)(5) to read as follows:

§ 1065.512 Duty cycle generation.

* * * * *

(b) * * *

(5) Ramped-modal cycles. For ramped-modal cycles, generate reference speed and 

torque values at 1 Hz and use this sequence of points to run the cycle and validate it in 

the same manner as with a transient cycle. During the transition between modes, linearly 

ramp the denormalized reference speed and torque values between modes to generate 

reference points at 1 Hz. Do not linearly ramp the normalized reference torque values 

between modes and then denormalize them. Do not linearly ramp normalized or 

denormalized reference power points. These cases will produce nonlinear torque ramps 

in the denormalized reference torques. If the speed and torque ramp runs through a point 

above the engine’s torque curve, continue to command the reference torques and allow 

the operator demand to go to maximum. Note that you may omit power and either torque 

or speed points from the cycle-validation criteria under these conditions as specified in § 

1065.514.

* * * * *

291. A new § 1065.516 is added to subpart F to read as follows:

§ 1065.516 Sample system decontamination and preconditioning.

This section describes how to manage the impact of sampling system contamination on 

emission measurements. Use good engineering judgement to determine if you should 

decontaminate and precondition your sampling system. Contamination occurs when a 

regulated pollutant accumulates in the sample system in a high enough concentration to 

cause release during emission tests. Hydrocarbons and PM are generally the only

regulated pollutants that contaminate sample systems. Note that although this section 

focuses on avoiding excessive contamination of sampling systems, you must also use 

good engineering judgment to avoid loss of sample to a sampling system that is too clean. 

The goal of decontamination is not to perfectly clean the sampling system, but rather to 

achieve equilibrium between the sampling system and the exhaust so emission 

components are neither lost to nor entrained from the sampling system.

(a) You may perform contamination checks as follows to determine if decontamination is 

needed:
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(1) For dilute exhaust sampling systems, measure hydrocarbon and PM emissions by

sampling with the CVS dilution air turned on, without an engine connected to it.

(2) For raw analyzers and systems that collect PM samples from raw exhaust, measure 

hydrocarbon and PM emissions by sampling purified air or nitrogen.

(3) When calculating zero emission levels, apply all applicable corrections, including 

initial THC contamination and diluted (CVS) exhaust background corrections.

(4) Sampling systems are considered contaminated if either of the following conditions 

applies:

(i) The hydrocarbon emission level exceeds 2 % of the flow-weighted mean 

concentration expected at the HC standard.

(ii) The PM emission level exceeds 5 % of the level expected at the standard and exceeds 

20 μg on a 47 mm PTFE membrane filter.

(b) To precondition or decontaminate sampling systems, use the following recommended 

procedure or select a different procedure using good engineering judgment:

(1) Start the engine and use good engineering judgment to operate it at a condition that 

generates high exhaust temperatures at the sample probe inlet.

(2) Operate any dilution systems at their expected flow rates. Prevent aqueous 

condensation in the dilution systems.

(3) Operate any PM sampling systems at their expected flow rates.

(4) Sample PM for at least 10 min using any sample media. You may change sample 

media at any time during this process and you may discard them without weighing them.

(5) You may purge any gaseous sampling systems that do not require decontamination 

during this procedure.

(6) You may conduct calibrations or verifications on any idle equipment or analyzers 

during this procedure.

(c) If your sampling system is still contaminated following the procedures specified in 

paragraph (b) of this section, you may use more aggressive procedures to decontaminate 

the sampling system, as long as the decontamination does not cause the sampling system 

to be cleaner than an equilibrium condition such that artificially low emission 

measurements may result.

292. A new § 1065.518 is added to subpart F to read as follows:

§ 1065.518 Engine preconditioning.

(a) This section applies for engines where measured emissions are affected by prior 

operation, such as with a diesel engine that relies on urea-based selective catalytic 

reduction. Note that § 1065.520(e) allows you to run practice duty cycles before the 

emission test; this section recommends how to do this for the purpose of preconditioning 

the engine. Follow the standard-setting part if it specifies a different engine 

preconditioning procedure.

(b) The intent of engine preconditioning is to manage the representativeness of emissions 

and emission controls over the duty cycle and to reduce bias.

(c) This paragraph (c) specifies the engine preconditioning procedures for different types 

of duty cycles. You must identify the amount of preconditioning before starting to 

precondition. You must run the predefined amount of preconditioning. You may
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measure emissions during preconditioning. You may not abort an emission test sequence 

based on emissions measured during preconditioning. For confirmatory testing, you may

ask us to run more preconditioning cycles than we specify in this paragraph (c); we will 

agree to this only if you show that additional preconditioning cycles are required to meet 

the intent of paragraph (b) of this section, for example, due to the effect of DPF 

regeneration on NH3 storage in the SCR catalyst. Perform preconditioning as follows, 

noting that the specific cycles for preconditioning are the same ones that apply for 

emission testing:

(1) Cold-start transient cycle. Precondition the engine by running at least one hot-start 

transient cycle. We will precondition your engine by running two hot-start transient 

cycles. Immediately after completing each preconditioning cycle, shut down the engine 

and complete the engine-off soak period. Immediately after completing the last 

preconditioning cycle, shut down the engine and begin the cold soak as described in § 

1065.530(a)(1).

(2) Hot-start transient cycle. Precondition the engine by running at least one hot-start 

transient cycle. We will precondition your engine by running two hot-start transient 

cycles. Immediately after completing each preconditioning cycle, shut down the engine, 

then start the next cycle (including the emission test) as soon as practical. For any repeat 

cycles, start the next cycle within 60 seconds after completing the last preconditioning 

cycle (this is optional for manufacturer testing).

(3) Hot-running transient cycle. Precondition the engine by running at least one hotrunning transient cycle. We will precondition your engine by running two hot-running 

transient cycles. Do not shut down the engine between cycles. Immediately after 

completing each preconditioning cycle, start the next cycle (including the emission test) 

as soon as practical. For any repeat cycles, start the next cycle within 60 seconds after 

completing the last preconditioning cycle (this is optional for manufacturer testing). See 

§ 1065.530(a)(1)(iii) for additional instructions if the cycle begins and ends under 

different operating conditions.

(4) Discrete-mode cycle for steady-state testing. Precondition the engine at the same 

operating condition as the next test mode, unless the standard-setting part specifies 

otherwise. We will precondition your engine by running it for at least five minutes 

before sampling.

(5) Ramped-modal cycle for steady-state testing. Precondition the engine by running at 

least the second half of the ramped-modal cycle, based on the number of test modes. For 

example, for the five-mode cycle specified in 40 CFR 1039.505(b)(1), the second half of 

the cycle consists of modes three through five. We will precondition your engine by

running one complete ramped-modal cycle. Do not shut down the engine between 

cycles. Immediately after completing each preconditioning cycle, start the next cycle 

(including the emission test) as soon as practical. For any repeat cycles, start the next 

cycle within 60 seconds after completing the last preconditioning cycle. See § 

1065.530(a)(1)(iii) for additional instructions if the cycle begins and ends under different 

operating conditions.

(d) You may conduct calibrations or verifications on any idle equipment or analyzers 

during engine preconditioning.
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293. Section 1065.520 is revised to read as follows:

§ 1065.520 Pre-test verification procedures and pre-test data collection.

(a) For tests in which you measure PM emissions, follow the procedures for PM sample 

preconditioning and tare weighing according to § 1065.590.

(b) Unless the standard-setting part specifies different tolerances, verify at some point 

before the test that ambient conditions are within the tolerances specified in this 

paragraph (b). For purposes of this paragraph (b), “before the test” means any time from 

a point just prior to engine starting (excluding engine restarts) to the point at which 

emission sampling begins.

(1) Ambient temperature of (20 to 30) °C. See § 1065.530(j) for circumstances under 

which ambient temperatures must remain within this range during the test. 

(2) Atmospheric pressure of (80.000 to 103.325) kPa and within ±5 kPa of the value 

recorded at the time of the last engine map. You are not required to verify atmospheric 

pressure prior to a hot start test interval for testing that also includes a cold start.

(3) Dilution air conditions as specified in § 1065.140, except in cases where you preheat 

your CVS before a cold start test. We recommend verifying dilution air conditions just 

prior to the start of each test interval.

(c) You may test engines at any intake-air humidity, and we may test engines at any

intake-air humidity.

(d) Verify that auxiliary-work inputs and outputs are configured as they were during 

engine mapping, as described in§ 1065.510(a).

(e) You may perform a final calibration of the speed, torque, and proportional-flow 

control systems, which may include performing practice duty cycles (or portions of duty

cycles). This may be done in conjunction with the preconditioning in § 1065.518.

(f) Verify the amount of nonmethane hydrocarbon contamination in the exhaust and 

background HC sampling systems within 8 hours before the start of the first test interval 

of each duty-cycle sequence for laboratory tests. You may verify the contamination of a 

background HC sampling system by reading the last bag fill and purge using zero gas. 

For any NMHC measurement system that involves separately measuring CH4 and 

subtracting it from a THC measurement or for any CH4 measurement system that uses an 

NMC, verify the amount of THC contamination using only the THC analyzer response. 

There is no need to operate any separate CH4 analyzer for this verification; however, you 

may measure and correct for THC contamination in the CH4 sample path for the cases 

where NMHC is determined by subtracting CH4 from THC or, where CH4 is determined, 

using an NMC as configured in § 1065.365(d), (e), and (f); and using the calculations in § 

1065.660(b)(2). Perform this verification as follows:

(1) Select the HC analyzer range for measuring the flow-weighted mean concentration 

expected at the HC standard.

(2) Zero the HC analyzer at the analyzer zero or sample port. Note that FID zero and span 

balance gases may be any combination of purified air or purified nitrogen that meets the 

specifications of § 1065.750. We recommend FID analyzer zero and span gases that 

contain approximately the flow-weighted mean concentration of O2 expected during 

testing.
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(3) Span the HC analyzer using span gas introduced at the analyzer span or sample port. 

Span on a carbon number basis of one (C1). For example, if you use a C3H8 span gas of 

concentration 200 mol/mol, span the FID to respond with a value of 600 mol/mol.

(4) Overflow zero gas at the HC probe inlet or into a tee near the probe outlet.

(5) Measure the THC concentration in the sampling and background systems as follows:

(i) For continuous sampling, record the mean THC concentration as overflow zero gas 

flows.

(ii) For batch sampling, fill the sample medium (e.g., bag) and record its mean THC 

concentration.

(iii) For the background system, record the mean THC concentration of the last fill and 

purge.

(6) Record this value as the initial THC concentration, xTHC[THC-FID]init, and use it to 

correct measured values as described in § 1065.660.

(7) You may correct the measured initial THC concentration for drift as follows:

(i) For batch and continuous HC analyzers, after determining the initial THC 

concentration, flow zero gas to the analyzer zero or sample port. When the analyzer 

reading is stable, record the mean analyzer value.

(ii) Flow span gas to the analyzer span or sample port. When the analyzer reading is 

stable, record the mean analyzer value.

(iii) Use mean analyzer values from paragraphs (f)(2), (f)(3), (f)(7)(i), and (f)(7)(ii) of 

this section to correct the initial THC concentration recorded in paragraph (f)(6) of this 

section for drift, as described in § 1065.550.

(8) If any of the xTHC[THC-FID]init values exceed the greatest of the following values, 

determine the source of the contamination and take corrective action, such as purging the 

system during an additional preconditioning cycle or replacing contaminated portions:

(i) 2 % of the flow-weighted mean concentration expected at the HC (THC or NMHC) 

standard.

(ii) 2 % of the flow-weighted mean concentration of HC (THC or NMHC) measured 

during testing.

(iii) 2 mol/mol.

(9) If corrective action does not resolve the deficiency, you may request to use the 

contaminated system as an alternate procedure under § 1065.10.

294. Section 1065.526 is revised to read as follows:

§ 1065.526 Repeating of void modes or test intervals.

(a) Test modes and test intervals can be voided because of instrument malfunction, 

engine stalling, emissions exceeding instrument ranges, and other unexpected deviations 

from the specified procedures. This section specifies circumstances for which a test 

mode or test interval can be repeated without repeating the entire test.

(b) This section is intended to result in replicate test modes and test intervals that are 

identical to what would have occurred if the cause of the voiding had not occurred. It 

does not allow you to repeat test modes or test intervals in any circumstances that would 

be inconsistent with good engineering judgment. For example, the procedures specified 

here for repeating a mode or interval may not apply for certain engines that include 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 847 of 1039

hybrid energy storage features or emission controls that involve physical or chemical 

storage of pollutants. This section applies for circumstances in which emission 

concentrations exceed the analyzer range only if it is due to operator error or analyzer 

malfunction. It does not apply for circumstances in which the emission concentrations 

exceed the range because they were higher than expected.

(c) If one of the modes of a discrete-mode duty cycle is voided while running the duty 

cycle as provided in this section, you may void the results for that individual mode and 

continue the duty cycle as follows: 

(1) If the engine has stalled or been shut down, restart the engine.

(2) Use good engineering judgment to restart the duty cycle using the appropriate steps in 

§ 1065.530(b). 

(3) Stabilize the engine by operating it at the mode at which the duty cycle was 

interrupted and continue with the duty cycle as specified in the standard-setting part.

(d) If an individual mode of a discrete-mode duty cycle sequence is voided after running 

the full duty cycle, you may void results for that mode and repeat testing for that mode as 

follows:

(1) Use good engineering judgment to restart the test sequence using the appropriate steps 

in § 1065.530(b).

(2) Stabilize the engine by operating it at that mode.

(3) Sample emissions over an appropriate test interval.

(4) If you sampled gaseous and PM emissions over separate test intervals for a voided 

mode, you must void both test intervals and repeat sampling of both gaseous and PM 

emissions for that mode.

(e) If a transient or ramped-modal cycle test interval is voided as provided in this section, 

you may repeat the test interval as follows:

(1) Use good engineering judgment to restart (as applicable) and precondition the engine 

to the same condition as would apply for normal testing. This may require you to 

complete the voided test interval. For example, you may generally repeat a hot-start test 

of a heavy-duty highway engine after completing the voided hot-start test and allowing 

the engine to soak for 20 minutes.

(2) Complete the remainder of the test according to the provisions in this subpart.

(f) Keep records from the voided test mode or test interval in the same manner as 

required for unvoided tests.

295. Section 1065.530 is amended by revising paragraphs (a), (b), and (c) to read as 

follows:

§ 1065.530 Emission test sequence.

(a) Time the start of testing as follows:

(1) Perform one of the following if you precondition the engine as described in § 

1065.518:

(i) For cold-start duty cycles, shut down the engine. Unless the standard-setting part 

specifies that you may only perform a natural engine cooldown, you may perform a 

forced engine cooldown. Use good engineering judgment to set up systems to send 

cooling air across the engine, to send cool oil through the engine lubrication system, to 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 848 of 1039

remove heat from coolant through the engine cooling system, and to remove heat from 

any exhaust aftertreatment systems. In the case of a forced aftertreatment cooldown, 

good engineering judgment would indicate that you not start flowing cooling air until the 

aftertreatment system has cooled below its catalytic activation temperature. For 

platinum-group metal catalysts, this temperature is about 200 °C. Once the aftertreatment

system has naturally cooled below its catalytic activation temperature, good engineering 

judgment would indicate that you use clean air with a temperature of at least 15 °C, and 

direct the air through the aftertreatment system in the normal direction of exhaust flow. 

Do not use any cooling procedure that results in unrepresentative emissions (see § 

1065.10(c)(1)). You may start a cold-start duty cycle when the temperatures of an 

engine’s lubricant, coolant, and aftertreatment systems are all between (20 and 30) °C. 

(ii) For hot-start emission measurements, shut down the engine immediately after 

completing the last preconditioning cycle. For any repeat cycles, start the hot-start 

transient emission test within 60 seconds after completing the last preconditioning cycle 

(this is optional for manufacturer testing). 

(iii) For testing that involves hot-stabilized emission measurements, such as any steadystate testing with a ramped-modal cycle, start the hot-stabilized emission test within 60 

seconds after completing the last preconditioning cycle (the time between cycles is 

optional for manufacturer testing). If the hot-stabilized cycle begins and ends with 

different operating conditions, add a linear transition period of 20 seconds between hotstabilized cycles where you linearly ramp the (denormalized) reference speed and torque 

values over the transition period. See § 1065.501(c)(2)(i) for discrete-mode cycles.

(2) If you do not precondition the engine as described in § 1065.518, perform one of the 

following:

(i) For cold-start duty cycles, prepare the engine according to paragraph (a)(1)(i) of this 

section.

(ii) For hot-start duty cycles, first operate the engine at any speed above peak-torque 

speed and at (65 to 85) % of maximum mapped power until either the engine coolant, 

block, or head absolute temperature is within ±2 % of its mean value for at least 2 min or 

until the engine thermostat controls engine temperature. Shut down the engine. Start the 

duty cycle within 20 min of engine shutdown.

(iii) For testing that involves hot-stabilized emission measurements, bring the engine 

either to warm idle or the first operating point of the duty cycle. Start the test within 10 

min of achieving temperature stability. Determine temperature stability either as the 

point at which the engine coolant, block, or head absolute temperature is within ±2 % of 

its mean value for at least 2 min, or as the point at which the engine thermostat controls 

engine temperature.

(b) Take the following steps before emission sampling begins:

(1) For batch sampling, connect clean storage media, such as evacuated bags or tareweighed filters.

(2) Start all measurement instruments according to the instrument manufacturer’s 

instructions and using good engineering judgment.

(3) Start dilution systems, sample pumps, cooling fans, and the data-collection system.
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Page 849 of 1039

(4) Pre-heat or pre-cool heat exchangers in the sampling system to within their operating 

temperature tolerances for a test.

(5) Allow heated or cooled components such as sample lines, filters, chillers, and pumps 

to stabilize at their operating temperatures.

(6) Verify that there are no significant vacuum-side leaks according to § 1065.345.

(7) Adjust the sample flow rates to desired levels, using bypass flow, if desired. 

(8) Zero or re-zero any electronic integrating devices, before the start of any test interval.

(9) Select gas analyzer ranges. You may automatically or manually switch gas analyzer 

ranges during a test only if switching is performed by changing the span over which the 

digital resolution of the instrument is applied. During a test you may not switch the gains 

of an analyzer’s analog operational amplifier(s).

(10) Zero and span all continuous analyzers using NIST-traceable gases that meet the 

specifications of § 1065.750. Span FID analyzers on a carbon number basis of one (1), 

C1. For example, if you use a C3H8 span gas of concentration 200 mol/mol, span the 

FID to respond with a value of 600 mol/mol. Span FID analyzers consistent with the 

determination of their respective response factors, RF, and penetration fractions, PF, 

according to § 1065.365.

(11) We recommend that you verify gas analyzer responses after zeroing and spanning by

sampling a calibration gas that has a concentration near one-half of the span gas 

concentration. Based on the results and good engineering judgment, you may decide 

whether or not to re-zero, re-span, or re-calibrate a gas analyzer before starting a test.

(12) Drain any accumulated condensate from the intake air system before starting a duty

cycle, as described in § 1065.125(e)(1). If engine and aftertreatment preconditioning 

cycles are run before the duty cycle, treat the preconditioning cycles and any associated 

soak period as part of the duty cycle for the purpose of opening drains and draining 

condensate. Note that you must close any intake air condensate drains that are not 

representative of those normally open during in-use operation.

(c) Start and run each test interval as described in this paragraph (c). The procedure 

varies depending on whether the test interval is part of a discrete-mode cycle, and 

whether the test interval includes engine starting. Note that the standard-setting part may

apply different requirements for running test intervals. For example, 40 CFR part 1033 

specifies a different way to perform discrete-mode testing.

(1) For steady-state discrete-mode duty cycles, start the duty cycle with the engine 

warmed-up and running as described in § 1065.501(c)(2)(i). Run each mode in the 

sequence specified in the standard-setting part. This will require controlling engine 

speed, engine load, or other operator demand settings as specified in the standard-setting 

part. Simultaneously start any electronic integrating devices, continuous data recording, 

and batch sampling. We recommend that you stabilize the engine for at least 5 minutes 

for each mode. Once sampling begins, sample continuously for at least 1 minute. Note 

that longer sample times may be needed for accurately measuring very low emission 

levels.

(2) For transient and steady-state ramped-modal duty cycles that do not include engine 

starting, start the test interval with the engine running as soon as practical after 
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Page 850 of 1039

completing engine preconditioning. Simultaneously start any electronic integrating 

devices, continuous data recording, batch sampling, and execution of the duty cycle.

(3) If engine starting is part of the test interval, simultaneously start any electronic 

integrating devices, continuous data recording, and batch sampling before attempting to 

start the engine. Initiate the sequence of points in the duty cycle when the engine starts.

(4) For batch sampling systems, you may advance or delay the start and end of sampling 

at the beginning and end of the test interval to improve the accuracy of the batch sample, 

consistent with good engineering judgment.

* * * * *

296. Section 1065.545 is revised to read as follows:

§ 1065.545 Verification of proportional flow control for batch sampling.

For any proportional batch sample such as a bag or PM filter, demonstrate that 

proportional sampling was maintained using one of the following, noting that you may

omit up to 5 % of the total number of data points as outliers:

(a) For any pair of flow rates, use recorded sample and total flow rates, where total flow 

rate means the raw exhaust flow rate for raw exhaust sampling and the dilute exhaust 

flow rate for CVS sampling, or their 1 Hz means with the statistical calculations in § 

1065.602. Determine the standard error of the estimate, SEE, of the sample flow rate 

versus the total flow rate. For each test interval, demonstrate that SEE was less than or 

equal to 3.5 % of the mean sample flow rate.

(b) For any pair of flow rates, use recorded sample and total flow rates, where total flow 

rate means the raw exhaust flow rate for raw exhaust sampling and the dilute exhaust 

flow rate for CVS sampling, or their 1 Hz means to demonstrate that each flow rate was 

constant within ±2.5 % of its respective mean or target flow rate. You may use the 

following options instead of recording the respective flow rate of each type of meter:

(1) Critical-flow venturi option. For critical-flow venturis, you may use recorded venturiinlet conditions or their 1 Hz means. Demonstrate that the flow density at the venturi 

inlet was constant within ±2.5 % of the mean or target density over each test interval. 

For a CVS critical-flow venturi, you may demonstrate this by showing that the absolute 

temperature at the venturi inlet was constant within ±4 % of the mean or target absolute 

temperature over each test interval. 

(2) Positive-displacement pump option. You may use recorded pump-inlet conditions or 

their 1 Hz means. Demonstrate that the flow density at the pump inlet was constant 

within ±2.5 % of the mean or target density over each test interval. For a CVS pump, 

you may demonstrate this by showing that the absolute temperature at the pump inlet was 

constant within ±2 % of the mean or target absolute temperature over each test interval.

(c) Using good engineering judgment, demonstrate with an engineering analysis that the 

proportional-flow control system inherently ensures proportional sampling under all 

circumstances expected during testing. For example, you might use CFVs for both 

sample flow and total dilute exhaust (CVS) flow and demonstrate that they always have 

the same inlet pressures and temperatures and that they always operate under critical-flow 

conditions.
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Page 851 of 1039

297. Section 1065.546 is amended by revising the section heading and the introductory

text to read as follows:

§ 1065.546 Verification of minimum dilution ratio for PM batch sampling.

Use continuous flows and/or tracer gas concentrations for transient and ramped-modal 

cycles to verify the minimum dilution ratios for PM batch sampling as specified in § 

1065.140(e)(2) over the test interval. You may use mode-average values instead of 

continuous measurements for discrete mode steady-state duty cycles. Determine the 

minimum primary and minimum overall dilution ratios using one of the following 

methods (you may use a different method for each stage of dilution):

* * * * *

298. Section 1065.550 is revised to read as follows:

§ 1065.550 Gas analyzer range verification and drift verification.

(a) Range verification. If an analyzer operated above 100 % of its range at any time 

during the test, perform the following steps:

(1) For batch sampling, re-analyze the sample using the lowest analyzer range that results 

in a maximum instrument response below 100 %. Report the result from the lowest range 

from which the analyzer operates below 100 % of its range.

(2) For continuous sampling, repeat the entire test using the next higher analyzer range. 

If the analyzer again operates above 100 % of its range, repeat the test using the next 

higher range. Continue to repeat the test until the analyzer always operates at less than 

100 % of its range.

(b) Drift verification. Gas analyzer drift verification is required for all gaseous exhaust 

constituents for which an emission standard applies. It is also required for CO2 even if 

there is no CO2 emission standard. It is not required for other gaseous exhaust 

constituents for which only a reporting requirement applies (such as CH4 and N2O).

(1) Verify drift using one of the following methods:

(i) For regulated exhaust constituents determined from the mass of a single component, 

perform drift verification based on the regulated constituent. For example, when NOx

mass is determined with a dry sample measured with a CLD and the removed water is 

corrected based on measured CO2, CO, THC, and NOx concentrations, you must verify 

the calculated NOx value.

(ii) For regulated exhaust constituents determined from the masses of multiple 

subcomponents, perform the drift verification based on either the regulated constituent or 

all the mass subcomponents. For example, when NOx is measured with separate NO and 

NO2 analyzers, you must verify either the NOx value or both the NO and NO2 values.

(iii) For regulated exhaust constituents determined from the concentrations of multiple 

gaseous emission subcomponents prior to performing mass calculations, perform drift 

verification on the regulated constituent. You may not verify the concentration 

subcomponents (e.g., THC and CH4 for NMHC) separately. For example, for NMHC 

measurements, perform drift verification on NMHC; do not verify THC and CH4

separately.

(2) Drift verification requires two sets of emission calculations. For each set of 

calculations, include all the constituents in the drift verification. Calculate one set using 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 852 of 1039

the data before drift correction and calculate the other set after correcting all the data for 

drift according to § 1065.672. Note that for purposes of drift verification, you must leave 

unaltered any negative emission results over a given test interval (i.e., do not set them to 

zero). These unaltered results are used when verifying either test interval results or 

composite brake-specific emissions over the entire duty cycle for drift. For each 

constituent to be verified, both sets of calculations must include the following:

(i) Calculated mass (or mass rate) emission values over each test interval.

(ii) If you are verifying each test interval based on brake-specific values, calculate brakespecific emission values over each test interval.

(iii) If you are verifying over the entire duty cycle, calculate composite brake-specific 

emission values.

(3) The duty cycle is verified for drift if you satisfy the following criteria:

(i) For each regulated gaseous exhaust constituent, you must satisfy one of the following:

(A) For each test interval of the duty cycle, the difference between the uncorrected and 

the corrected brake-specific emission values of the regulated constituent must be within 

±4 % of the uncorrected value or the applicable emissions standard, whichever is greater. 

Alternatively, the difference between the uncorrected and the corrected emission mass (or 

mass rate) values of the regulated constituent must be within 4 % of the uncorrected 

value or the composite work (or power) multiplied by the applicable emissions standard, 

whichever is greater. For purposes of verifying each test interval, you may use either the 

reference or actual composite work (or power).

(B) For each test interval of the duty cycle and for each mass subcomponent of the 

regulated constituent, the difference between the uncorrected and the corrected brakespecific emission values must be within ±4 % of the uncorrected value. Alternatively, the 

difference between the uncorrected and the corrected emissions mass (or mass rate) 

values must be within ±4 % of the uncorrected value.

(C) For the entire duty cycle, the difference between the uncorrected and the corrected 

composite brake-specific emission values of the regulated constituent must be within ±4 

% of the uncorrected value or applicable emission standard, whichever is greater.

(D) For the entire duty cycle and for each subcomponent of the regulated constituent, the 

difference between the uncorrected and the corrected composite brake-specific emission 

values must be within ±4 % of the uncorrected value.

(ii) Where no emission standard applies for CO2, you must satisfy one of the following:

(A) For each test interval of the duty cycle, the difference between the uncorrected and 

the corrected brake-specific CO2 values must be within ±4 % of the uncorrected value; or 

the difference between the uncorrected and the corrected CO2 mass (or mass rate) values 

must be within ±4 % of the uncorrected value.

(B) For the entire duty cycle, the difference between the uncorrected and the corrected 

composite brake-specific CO2 values must be within ±4 % of the uncorrected value.

(4) If the test is not verified for drift as described in paragraph (b)(1) of this section, you

may consider the test results for the duty cycle to be valid only if, using good engineering 

judgment, the observed drift does not affect your ability to demonstrate compliance with 

the applicable emission standards. For example, if the drift-corrected value is less than 

the standard by at least two times the absolute difference between the uncorrected and 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 853 of 1039

corrected values, you may consider the data to be verified for demonstrating compliance 

with the applicable standard.

Subpart G—[Amended]

[Note to Editor: The equations and other mathematical expressions in this subpart 

depend on careful use of italics. In general, variable expressions are italicized and 

subscripts are not. Please take steps to avoid changing the font from the original 

Word file. This has been a problem in some published rules.]

299. Section 1065.601 is amended by revising paragraph (b) to read as follows:

§ 1065.601 Overview.

* * * * *

(b) You may use data from multiple systems to calculate test results for a single emission 

test, consistent with good engineering judgment. You may also make multiple 

measurements from a single batch sample, such as multiple weighings of a PM filter or 

multiple readings from a bag sample. Although you may use an average of multiple 

measurements from a single test, you may not use test results from multiple emission 

tests to report emissions.

(1) We allow weighted means where appropriate.

(2) You may discard statistical outliers, but you must report all results.

(3) For emission measurements related to durability testing, we may allow you to exclude 

certain test points other than statistical outliers relative to compliance with emission 

standards, consistent with good engineering judgment and normal measurement 

variability; however, you must include these results when calculating the deterioration 

factor. This would allow you to use durability data from an engine that has an 

intermediate test result above the standard that cannot be discarded as a statistical outlier, 

as long as good engineering judgment indicates that the test result does not represent the 

engine’s actual emission level. Note that good engineering judgment would preclude you 

from excluding endpoints. Also, if normal measurement variability causes emission 

results below zero, include the negative result in calculating the deterioration factor to 

avoid an upward bias. These provisions related to durability testing are intended to 

address very stringent standards where measurement variability is large relative to the 

emission standard.

* * * * *

300. Section 1065.602 is amended by revising paragraphs (f), (j), (k), and (l)(1)(ii) to 

read as follows:

§ 1065.602 Statistics.

* * * * *

(f) t-test. Determine if your data passes a t-test by using the following equations and 

tables:

(1) For an unpaired t-test, calculate the t statistic and its number of degrees of freedom, , 

as follows:
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Page 854 of 1039

ref

2 2

ref y

ref

y y

t

N N

 







Eq. 1065.602-5

2

2 2

ref y

ref

2 2 2

2

y

ref

ref

ref 1 1

N N

v

N N

N N

 

 

    

 



              

 

Eq. 1065.602-6

Example:

ref y = 1205.3

y = 1123.8

ref = 9.399

y = 10.583

Nref = 11

N = 7

2 2

1205.3 1123.8

9.399 10.583

11 7

t







t = 16.63

ref = 9.399

y = 10.583

Nref = 11

N = 7

2

2 2

2 2 2 2

9.399 10.583

11 7

9.399 10.583

11 7

11 1 7 1

v

    

 



            

 

v = 11.76

(2) For a paired t-test, calculate the t statistic and its number of degrees of freedom, , as 

follows, noting that the i

 are the errors (e.g., differences) between each pair of yrefi and 

yi:
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Page 855 of 1039

ε

N

t









Eq. 1065.602-7

Example:

 = –0.12580

N = 16

 ε = 0.04837

0.12580 16

0.04837

t

 



t = 10.403

v = N – 1

Example:

N = 16

v = 16 – 1 

v = 15

(3) Use Table 1 of this section to compare t to the tcrit values tabulated versus the number 

of degrees of freedom. If t is less than tcrit, then t passes the t-test. The Microsoft Excel 

software has a TINV function that returns results equivalent results and may be used in 

place of Table 1, which follows:
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Page 856 of 1039

TABLE 1 OF § 1065.602–

CRITICAL t VALUES VERSUS NUMBER OF DEGREES OF FREEDOM, 

1



Confidence

90% 95%

1 6.314 12.706

2 2.920 4.303

3 2.353 3.182

4 2.132 2.776

5 2.015 2.571

6 1.943 2.447

7 1.895 2.365

8 1.860 2.306

9 1.833 2.262

10 1.812 2.228

11 1.796 2.201

12 1.782 2.179

13 1.771 2.160

14 1.761 2.145

15 1.753 2.131

16 1.746 2.120

18 1.734 2.101

20 1.725 2.086

22 1.717 2.074

24 1.711 2.064

26 1.706 2.056

28 1.701 2.048

30 1.697 2.042

35 1.690 2.030

40 1.684 2.021

50 1.676 2.009

70 1.667 1.994

100 1.660 1.984

1000+ 1.645 1.960

1 Use linear interpolation to 

establish values not shown here.

* * * * *

(j) Standard estimate of error. Calculate a standard estimate of error, SEE, as follows:

2

i 0y 1y refi

i 1

y

( )

2

N

y a a y

SEE

N



    

 






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Page 857 of 1039

Eq. 1065.602-11

Example:

N = 6000

y1 = 2045.8

a0y = –16.8083 

a1y = 1.0110

yref1= 2045.0

 

2 2

6000 ref 6000

y

2045.8 ( 16.8083) (1.0110 2045.0) ... ( 16.8083) (1.0110 )

6000 2

y y

SEE

          

 





SEEy = 5.348

(k) Coefficient of determination. Calculate a coefficient of determination, 2

y

r , as follows:

 

2

i 0y 1y refi

2 i 1

y

2

i

i 1

( )

1

N

N

y a a y

r

y y





    

 

 







Eq. 1065.602-12

Example:

N = 6000

y1 = 2045.8

a0y = –16.8083 

a1y = 1.0110

yref1 = 2045.0

y = 1480.5

 

 

2 2

2 6000 ref6000

y 2 2

6000

2045.8 ( 16.8083) (1.0110 2045.0) ... ( 16.8083) (1.0110 )

1

2045.8 1480.5 ... 1480.5

y y

r

y

          

 

 

      

2

y

r = 0.9859

(l) * * *

(1) * * *

(ii) Based on your engine design, estimate maximum power, Pmax, the design speed at 

maximum power, fnmax, the design maximum intake manifold boost pressure, pinmax, and 

temperature, Tinmax. Also, estimate a mean fraction of power that is lost due to friction 

and pumping, Pfrict . Use this information along with the engine displacement volume, 

Vdisp, an approximate volumetric efficiency, V, and the number of engine strokes per 

power stroke (two-stroke or four-stroke), Nstroke, to estimate the maximum raw exhaust 

molar flow rate, exhmax n . 

* * * * *
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Page 858 of 1039

301. Section 1065.610 is amended by revising paragraphs (a) introductory text, (a)(1), 

(c)(3), and (d)(3)(ii) to read as follows:

§ 1065.610 Duty cycle generation.

* * * * *

(a) Maximum test speed, fntest. This section generally applies to duty cycles for variablespeed engines. For constant-speed engines subject to duty cycles that specify normalized 

speed commands, use the no-load governed speed as the measured fntest. This is the 

highest engine speed where an engine outputs zero torque. For variable-speed engines, 

determine fntest as follows:

(1) Develop a measured value for fntest as follows:

(i) Determine maximum power, Pmax, from the engine map generated according to § 

1065.510 and calculate the value for power equal to 98 % of Pmax. 

(ii) Determine the lowest and highest engine speeds corresponding to 98 % of Pmax, using

linear interpolation as appropriate.

(iii) Determine the engine speed corresponding to maximum power, fnPmax, by calculating 

the average of the two speed values from paragraph (a)(1)(ii) of this section. 

(iv) Transform the map into a normalized power-versus-speed map by dividing power 

terms by Pmax and dividing speed terms by fnPmax. Use the following equation to calculate 

a quantity representing the sum of squares from the normalized map:

2 2 Sum of squares nnormi normi   f P

Eq. 1065.610-1

Where:

i = an indexing variable that represents one recorded value of an engine map.

fnnormi = an engine speed normalized by dividing it by fnPmax.

Pnormi = an engine power normalized by dividing it by Pmax.

(v) Determine the maximum value for the sum of the squares from the map and multiply

that value by 0.98. 

(vi) Determine the lowest and highest engine speeds corresponding to the value 

calculated in paragraph (a)(1)(v) of this section, using linear interpolation as appropriate. 

Calculate fntest as the average of these two speed values.

(viii) The following example illustrates a calculation of fntest:

(fn1 = 2360, P1 = 223.1, fnnorm1 = 1.002, Pnorm1 = 0.967)

(fn2 = 2364, P2 = 227.7, fnnorm2 = 1.004, Pnorm2 = 0.986)

(fn3 = 2369, P3 = 230.0, fnnorm3 = 1.006, Pnorm3 = 0.994)

(fn4 = 2374, P4 = 220.8, fnnorm4 = 1.008, Pnorm4 = 0.951)

   

ntest

0.98 230.0 223.1 0.98 230.0 230.0 2360 2364 2360 2369 2374 2369

227.7 223.1 220.8 230.0

2

2363 2371 2367r min

2

f

         

                    





 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 859 of 1039

Sum of squares = (1.0022+ 0.9672) = 1.94

Sum of squares = (1.0042+ 0.9862) = 1.98

Sum of squares = (1.0062+ 0.9942) = 2.00

Sum of squares = (1.0082+ 0.9512) = 1.92

   

npmax

0.98 2.0 1.94 0.98 2.0 2.0 2360 2364 2360 2369 2374 2369

1.98 1.94 1.92 2.0

2

2363 2371 2367 r min

2

f

         

      

             





 

* * * * *

(c) * * *

(3) Intermediate speed. Based on the map, determine maximum torque, Tmax, and the 

corresponding speed, fnTmax, calculated as the average of the lowest and highest speeds at 

which torque is equal to 98 % of Tmax. Use linear interpolation between points to 

determine the speeds where torque is equal to 98% of Tmax. Identify your reference 

intermediate speed as one of the following values:

(i) fnTmax if it is between (60 and 75) % of maximum test speed.

(ii) 60 % of maximum test speed if fnTmax is less than 60 % of maximum test speed.

(iii) 75 % of maximum test speed if fnTmax is greater than 75 % of maximum test speed.

(d) * * *

(3) * * *

(ii) If the cycle begins with a set of contiguous idle points (zero-percent speed, and zeropercent torque), leave the reference torques set to zero for this initial contiguous idle 

segment. This is to represent free idle operation with the transmission in neutral or park 

at the start of the transient duty cycle, after the engine is started. If the initial idle 

segment is longer than 24 seconds, change the reference torques for the remaining idle 

points in the initial contiguous idle segment to CITT (i.e., change idle points 

corresponding to 25 seconds to the end of the initial idle segment to CITT). This is to 

represent shifting the transmission to drive.

* * * * *

302. Section 1065.630 is revised to read as follows:

§ 1065.630 Local acceleration of gravity.

(a) The acceleration of Earth’s gravity, ag, varies depending on the test location. 

Determine ag at your location by entering latitude, longitude, and elevation data into the 

U.S. National Oceanographic and Atmospheric Administration’s surface gravity 

prediction Web site at http://www.ngs.noaa.gov/cgi-bin/grav_pdx.prl. 

(b) If the Web site specified in paragraph (a) of this section is unavailable, you may

calculate ag for your latitude as follows:

ag = 9.7803267715 ∙ [1 + 5.2790414 ∙ 10-3∙sin2() + 2.32718 ∙ 10-5∙sin4()

+ 1.262 ∙ 10-7∙sin6() + 7 ∙ 10-10∙sin8()]

Eq. 1065.630-1
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 860 of 1039

Where:

 = Degrees north or south latitude.

Example:

 = 45 °

ag = 9.7803267715 ∙ (1 + 5.2790414 ∙ 10-3∙sin2(45) + 2.32718 ∙ 10-5∙sin4(45)

+ 1.262 ∙ 10-7∙sin6(45) + 7 ∙ 10-10∙sin8(45) 

ag = 9.8061992026 m/s2

303. Section 1065.640 is revised to read as follows:

§ 1065.640 Flow meter calibration calculations.

This section describes the calculations for calibrating various flow meters. After you 

calibrate a flow meter using these calculations, use the calculations described in § 

1065.642 to calculate flow during an emission test. Paragraph (a) of this section first 

describes how to convert reference flow meter outputs for use in the calibration 

equations, which are presented on a molar basis. The remaining paragraphs describe the 

calibration calculations that are specific to certain types of flow meters.

(a) Reference meter conversions. The calibration equations in this section use molar flow 

rate, ref n , as a reference quantity. If your reference meter outputs a flow rate in a 

different quantity, such as standard volume rate, Vstdref

 , actual volume rate, Vactref , or mass 

rate, mref  , convert your reference meter output to a molar flow rate using the following

equations, noting that while values for volume rate, mass rate, pressure, temperature, and 

molar mass may change during an emission test, you should ensure that they are as 

constant as practical for each individual set point during a flow meter calibration:

stdref std actref act ref

ref

std act mix

V p V p m

n

T R T R M

 



 

  



Eq. 1065.640-1

Where:

ref n = reference molar flow rate.

Vstdref

 = reference volume flow rate, corrected to a standard pressure and a standard 

temperature.

Vactref

 = reference volume flow rate at the actual pressure and temperature of the flow rate.

mref  = reference mass flow.

pstd = standard pressure.

pact = actual pressure of the flow rate.

Tstd = standard temperature.

Tact = actual temperature of the flow rate.

R = molar gas constant.

Mmix = molar mass of the flow rate.

Example 1:

Vstdref

 = 1000.00 ft3

/min = 0.471948 m3/s
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 861 of 1039

pstd = 29.9213 in Hg @ 32 °F = 101.325 kPa = 101325 Pa = 101325 kg/(m∙s2)

Tstd = 68.0 °F = 293.15 K

R = 8.314472 J/(mol∙K) = 8.314472 (m2∙kg)/(s2∙mol∙K)

ref

0.471948 101325

293.15 8.314472

n









ref n = 19.619 mol/s

Example 2: 

mref  = 17.2683 kg/min = 287.805 g/s

Mmix = 28.7805 g/mol

ref

287.805

28.7805

n 

ref n = 10.0000 mol/s

(b) PDP calibration calculations. For each restrictor position, calculate the following 

values from the mean values determined in § 1065.340, as follows:

(1) PDP volume pumped per revolution, Vrev (m3/r):

ref in

rev

in nPDP

n R T

V

p f

 







Eq. 1065.640-2 

Example:

ref n = 25.096 mol/s

R = 8.314472 J/(mol∙K) = 8.314472 (m2∙kg)/(s2∙mol∙K)

Tin = 299.5 K

in p = 98.290 kPa = 98290 Pa = 98290 kg/(m∙s2

)

nPDP f = 1205.1 r/min = 20.085 r/s

25.096 8.314472 299.5

98290 20.085

Vrev

 





Vrev = 0.03166 m3/r

(2) PDP slip correction factor, Ks (s/r):

out in

s

nPDP out

1 p p K

f p



 

Eq. 1065.640-3

Example:

nPDP f = 1205.1 r/min = 20.085 r/s

out p = 100.103 kPa

in p = 98.290 kPa
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 862 of 1039

s

1 100.103 98.290

20.085 100.103

K



 

Ks = 0.006700 s/r

(3) Perform a least-squares regression of PDP volume pumped per revolution, Vrev, versus 

PDP slip correction factor, Ks, by calculating slope, a1, and intercept, a0, as described in § 

1065.602.

(4) Repeat the procedure in paragraphs (b)(1) through (3) of this section for every speed 

that you run your PDP.

(5) The following example illustrates these calculations:

TABLE 1 OF § 1065.640–

EXAMPLE OF PDP CALIBRATION DATA

nPDP f

(revolution/s)

a1 

(m3/s)

a0 

(m3/revolution)

12.6 0.841 0.056

16.5 0.831 -0.013

20.9 0.809 0.028

23.4 .788 -0.061

(6) For each speed at which you operate the PDP, use the corresponding slope, a1, and 

intercept, a0, to calculate flow rate during emission testing as described in § 1065.642.

(c) Venturi governing equations and permissible assumptions. This section describes the 

governing equations and permissible assumptions for calibrating a venturi and calculating 

flow using a venturi. Because a subsonic venturi (SSV) and a critical-flow venturi (CFV) 

both operate similarly, their governing equations are nearly the same, except for the 

equation describing their pressure ratio, r (i.e., rSSV versus rCFV). These governing 

equations assume one-dimensional isentropic inviscid compressible flow of an ideal gas. 

In paragraph (c)(4) of this section, we describe other assumptions that you may make, 

depending upon how you conduct your emission tests. If we do not allow you to assume 

that the measured flow is an ideal gas, the governing equations include a first-order 

correction for the behavior of a real gas; namely, the compressibility factor, Z. If good 

engineering judgment dictates using a value other than Z=1, you may either use an 

appropriate equation of state to determine values of Z as a function of measured pressures 

and temperatures, or you may develop your own calibration equations based on good 

engineering judgment. Note that the equation for the flow coefficient, Cf, is based on the 

ideal gas assumption that the isentropic exponent, , is equal to the ratio of specific heats, 

Cp/Cv. If good engineering judgment dictates using a real gas isentropic exponent, you 

may either use an appropriate equation of state to determine values of  as a function of 

measured pressures and temperatures, or you may develop your own calibration 

equations based on good engineering judgment. Calculate molar flow rate, , as 

follows:

t in

d f

mix in

A p n C C

Z M R T



  

  


*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 863 of 1039

Eq. 1065.640-4

Where:

Cd = discharge coefficient, as determined in paragraph (c)(1) of this section.

Cf = flow coefficient, as determined in paragraph (c)(2) of this section.

At = venturi throat cross-sectional area.

pin = venturi inlet absolute static pressure.

Z = compressibility factor.

Mmix = molar mass of gas mixture.

R = molar gas constant.

Tin = venturi inlet absolute temperature.

(1) Using the data collected in § 1065.340, calculate Cd using the following equation:

mix in

d ref

f t in

Z M R T

C n

C A p

  

 

 



Eq. 1065.640-5

Where: 

ref n = a reference molar flow rate.

(2) Determine Cf using one of the following methods:

(i) For CFV flow meters only, determine CfCFV from the following table based on your 

values for  and , using linear interpolation to find intermediate values:
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 864 of 1039

TABLE 2 OF § 1065.640–

CfCFV VERSUS  AND  FOR CFV FLOW METERS

CfCFV



exh =

1.385

dexh =

air=

1.399

0.000 0.6822 0.6846

0.400 0.6857 0.6881

0.500 0.6910 0.6934

0.550 0.6953 0.6977

0.600 0.7011 0.7036

0.625 0.7047 0.7072

0.650 0.7089 0.7114

0.675 0.7137 0.7163

0.700 0.7193 0.7219

0.720 0.7245 0.7271

0.740 0.7303 0.7329

0.760 0.7368 0.7395

0.770 0.7404 0.7431

0.780 0.7442 0.7470

0.790 0.7483 0.7511

0.800 0.7527 0.7555

0.810 0.7573 0.7602

0.820 0.7624 0.7652

0.830 0.7677 0.7707

0.840 0.7735 0.7765

0.850 0.7798 0.7828

(ii) For any CFV or SSV flow meter, you may use the following equation to calculate Cf :

 

   

1

2

1

2

f

4

2 1

1

r

C

r









 





 

  

 



  

 

Eq. 1065.640-6

Where:

 = isentropic exponent. For an ideal gas, this is the ratio of specific heats of the gas 

mixture, Cp/Cv.

r = pressure ratio, as determined in paragraph (c)(3) of this section.

 = ratio of venturi throat to inlet diameters.

(3) Calculate r as follows:

(i) For SSV systems only, calculate rSSV using the following equation:
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 865 of 1039

SSV

SSV

in

1

p

r

p



 

Eq. 1065.640-7

Where:

ΔpSSV = Differential static pressure; venturi inlet minus venturi throat.

(ii) For CFV systems only, calculate rCFV iteratively using the following equation:

1 2

4

CFV CFV

1 1

2 2

r r



 

 





   

       

Eq. 1065.640-8

(4)You may make any of the following simplifying assumptions of the governing 

equations, or you may use good engineering judgment to develop more appropriate 

values for your testing:

(i) For emission testing over the full ranges of raw exhaust, diluted exhaust and dilution 

air, you may assume that the gas mixture behaves as an ideal gas: Z=1.

(ii) For the full range of raw exhaust you may assume a constant ratio of specific heats of 

=1.385.

(iii) For the full range of diluted exhaust and air (e.g., calibration air or dilution air), you 

may assume a constant ratio of specific heats of =1.399.

(iv) For the full range of diluted exhaust and air, you may assume the molar mass of the 

mixture is a function only of the amount of water in the dilution air or calibration air, 

xH2O, determined as described in § 1065.645, as follows:

Mmix = Mair ∙ (1 – xH2O) + MH2O ∙ xH2O

Eq. 1065.640-9

Example:

Mair = 28.96559 g/mol

xH2O = 0.0169 mol/mol

MH2O = 18.01528 g/mol

Mmix = 28.96559 ∙ (1– 0.0169) + 18.01528 ∙ 0.0169

Mmix = 28.7805 g/mol 

(v) For the full range of diluted exhaust and air, you may assume a constant molar mass 

of the mixture, Mmix, for all calibration and all testing as long as your assumed molar 

mass differs no more than ±1 % from the estimated minimum and maximum molar mass 

during calibration and testing. You may assume this, using good engineering judgment, 

if you sufficiently control the amount of water in calibration air and in dilution air or if 

you remove sufficient water from both calibration air and dilution air. The following 

table gives examples of permissible ranges of dilution air dewpoint versus calibration air 

dewpoint:
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 866 of 1039

TABLE 3 OF § 1065.640–

EXAMPLES OF DILUTION AIR AND CALIBRATION AIR 

DEWPOINTS AT WHICH YOU MAY ASSUME A CONSTANT Mmix

If calibration 

Tdew (C) is...

assume the following 

constant Mmix (g/mol)...

for the following ranges of Tdew

(C) during emission testsa

dry 28.96559 dry to 18

0 28.89263 dry to 21

5 28.86148 dry to 22

10 28.81911 dry to 24

15 28.76224 dry to 26

20 28.68685 -8 to 28

25 28.58806 12 to 31

30 28.46005 23 to 34

aRange valid for all calibration and emission testing over the atmospheric 

pressure range (80.000 to 103.325) kPa.

(5) The following example illustrates the use of the governing equations to calculate the 

discharge coefficient, Cd of an SSV flow meter at one reference flow meter value. Note 

that calculating Cd for a CFV flow meter would be similar, except that Cf would be 

determined from Table 2 of this section or calculated iteratively using values of  and  

as described in paragraph (c)(2) of this section.

Example:

ref n = 57.625 mol/s

Z = 1

Mmix = 28.7805 g/mol = 0.0287805 kg/mol

R = 8.314472 J/(mol∙K) = 8.314472 (m2∙kg)/(s2∙mol∙K)

Tin = 298.15 K

At = 0.01824 m2

pin = 99.132 kPa = 99132.0 Pa = 99132 kg/(m∙s2)

 = 1.399

 = 0.8

Δp = 2.312 kPa

SSV

2.312 1 0.977

99.132

r   

 

   

1.399 1

1.399

2

1.399

1

2

f

4

2 1.399 0.977 1

1.399 1 0.8 0.977

C





    

  

  

 

Cf = 0.274

d

1 0.0287805 8.314472 298.15 57.625

0.274 0.01824 99132.0

C

  

 

 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 867 of 1039

Cd = 0.982

(d) SSV calibration. Perform the following steps to calibrate an SSV flow meter:

(1) Calculate the Reynolds number, Re#, for each reference molar flow rate, ref n , using

the throat diameter of the venturi, dt. Because the dynamic viscosity, μ, is needed to 

compute Re#, you may use your own fluid viscosity model to determine μ for your 

calibration gas (usually air), using good engineering judgment. Alternatively, you may

use the Sutherland three-coefficient viscosity model to approximate μ, as shown in the 

following sample calculation for Re#:

# mix ref

t

4 M n Re =

  d

 

 



Eq. 1065.640-10

Where, using the Sutherland three-coefficient viscosity model:

3

2

in 0

0

0 in

T T S

T T S

 

    

           

Eq. 1065.640-11

Where:

μ0 = Sutherland reference viscosity.

T0 = Sutherland reference temperature.

S = Sutherland constant.

TABLE 4 OF § 1065.640–

SUTHERLAND THREE-COEFFICIENT VISCOSITY MODEL PARAMETERS

Gasa μ0 T0 S

Temp range 

within ±2 % 

errorb

Pressure 

limitb

kg/(m∙s) K K K kPa

Air 1.716∙10-5273 111 170 to 1900 ≤ 1800

CO2 1.370∙10-5273 222 190 to 1700 ≤ 3600

H2O 1.12∙10-5350 1064 360 to 1500 ≤ 10000 

O2 1.919∙10-5273 139 190 to 2000 ≤ 2500

N2 1.663∙10-5273 107 100 to 1500 ≤ 1600

aUse tabulated parameters only for the pure gases, as listed. Do not combine 

parameters in calculations to calculate viscosities of gas mixtures.

bThe model results are valid only for ambient conditions in the specified 

ranges.

Example:

μ0 = 1.716∙10-5kg/(m∙s)

T0 = 273 K

S = 111 K
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 868 of 1039

3

2

5 298.15 273 111 1.716 10

273 298.15 111



     

            

μ = 1.838∙10-5kg/(m∙s)

Mmix = 28.7805 g/mol

ref n = 57.625 mol/s

dt = 152.4 mm = 0.1524 m

Tin = 298.15 K

#

5

4 28.7805 57.625

3.14159 0.1524 1.838 10

Re = 

 

  

Re#= 7.538∙108

(2) Create an equation for Cd as a function of Re#, using paired values of the two 

quantities. The equation may involve any mathematical expression, including a 

polynomial or a power series. The following equation is an example of a commonly used 

mathematical expression for relating Cd and Re#:

6

d 0 1 #

10 C a a

Re

  

Eq. 1065.640-12

(3) Perform a least-squares regression analysis to determine the best-fit coefficients for 

the equation and calculate the equation’s regression statistic, SEE, according to § 

1065.602.

(4) If the equation meets the criterion of SEE ≤ 0.5 %, you may use the equation to 

determine Cd for emission tests, as described in § 1065.642.

(5) If the equation does not meet the specified statistical criterion, you may use good 

engineering judgment to omit calibration data points; however you must use at least 

seven calibration data points to demonstrate that you meet the statistical criterion. This 

will usually involve narrowing the range of flow rates for a better curve fit.

(6) Take corrective action if the equation does not meet the specified statistical criterion 

even after omitting calibration data points. For example, select another mathematical 

expression for the Cd versus Re#equation, check for leaks, or repeat the calibration 

process. If you must repeat the process, we recommend applying tighter tolerances to 

measurements and allowing more time for flows to stabilize.

(7) Once you have an equation that meets the specified statistical criterion, you may use 

the equation only for the corresponding range of Re#.

(e) CFV calibration. Some CFV flow meters consist of a single venturi and some consist 

of multiple venturis, where different combinations of venturis are used to meter different 

flow rates. For CFV flow meters that consist of multiple venturis, either calibrate each 

venturi independently to determine a separate discharge coefficient, Cd, for each venturi, 

or calibrate each combination of venturis as one venturi. In the case where you calibrate 

a combination of venturis, use the sum of the active venturi throat areas as At, the square 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 869 of 1039

root of the sum of the squares of the active venturi throat diameters as dt, and the ratio of 

the venturi throat to inlet diameters as the ratio of the square root of the sum of the active 

venturi throat diameters (dt) to the diameter of the common entrance to all the venturis 

(D). To determine the Cd for a single venturi or a single combination of venturis, perform 

the following steps:

(1) Use the data collected at each calibration set point to calculate an individual Cd for 

each point using Eq. 1065.640-4.

(2) Calculate the mean and standard deviation of all the Cd values according to Eqs. 

1065.602-1 and 1065.602-2.

(3) If the standard deviation of all the Cd values is less than or equal to 0.3 % of the mean 

Cd, use the mean Cd in Eq. 1065.642-4, and use the CFV only up to the highest r

measured during calibration using the following equation:

CFV

in

1

p

r

p



 

Eq. 1065.640-13

Where:

pCFV = Differential static pressure; venturi inlet minus venturi outlet.

(4) If the standard deviation of all the Cd values exceeds 0.3 % of the mean Cd, omit the 

Cd value corresponding to the data point collected at the highest r measured during 

calibration.

(5) If the number of remaining data points is less than seven, take corrective action by 

checking your calibration data or repeating the calibration process. If you repeat the 

calibration process, we recommend checking for leaks, applying tighter tolerances to 

measurements and allowing more time for flows to stabilize.

(6) If the number of remaining Cd values is seven or greater, recalculate the mean and 

standard deviation of the remaining Cd values.

(7) If the standard deviation of the remaining Cd values is less than or equal to 0.3 % of 

the mean of the remaining Cd, use that mean Cd in Eq. 1065.642-4, and use the CFV 

values only up to the highest r associated with the remaining Cd.

(8) If the standard deviation of the remaining Cd still exceeds 0.3 % of the mean of the 

remaining Cd values, repeat the steps in paragraph (e)(4) through (8) of this section.

304. Section 1065.642 is revised to read as follows:

§ 1065.642 SSV, CFV, and PDP molar flow rate calculations.

This section describes the equations for calculating molar flow rates from various flow 

meters. After you calibrate a flow meter according to § 1065.640, use the calculations 

described in this section to calculate flow during an emission test. 

(a) PDP molar flow rate. Based upon the speed at which you operate the PDP for a test 

interval, select the corresponding slope, a1, and intercept, a0, as calculated in § 1065.640, 

to calculate molar flow rate, n as follows:

in rev

nPDP

in

p V n f

R T



 




*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 870 of 1039

Eq. 1065.642-1

Where:

1 out in

rev 0

nPDP out

a p p V a

f p



  

Eq. 1065.642-2

Example:

a1 = 0.8405 (m3/s)

fnPDP = 12.58 r/s

pout = 99.950 kPa

pin = 98.575 kPa = 98575 Pa = 98575 kg/(m∙s2)

a0 = 0.056 (m3/r)

R = 8.314472 J/(mol∙K) = 8.314472 (m2∙kg)/(s2∙mol∙K)

Tin = 323.5 K

rev

0.8405 99.950 98.575 0.056

12.58 99.950

V



  

Vrev = 0.06383 m3/r

98575 0.06383 12.58

8.314472 323.5

n



 





n = 29.428 mol/s

(b) SSV molar flow rate. Based on the Cd versus Re#equation you determined according 

to § 1065.640, calculate SSV molar flow rate, n during an emission test as follows: 

t in

d f

mix in

A p n C C

Z M R T



  

  



Eq. 1065.642-3

Example: 

At = 0.01824 m2

pin = 99.132 kPa = 99132 Pa = 99132 kg/(m∙s2)

Z = 1

Mmix = 28.7805 g/mol = 0.0287805 kg/mol

R = 8.314472 J/(mol·K) = 8.314472 (m2∙kg)/(s2∙mol∙K)

Tin = 298.15 K

Re#= 7.232·105

 = 1.399

 = 0.8

p = 2.312 kPa

Using Eq. 1065.640-7,

rssv = 0.997

Using Eq. 1065.640-6,
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 871 of 1039

Cf = 0.274

Using Eq. 1065.640-5,

Cd = 0.990

0.01824 99132 0.990 0.274

1 0.0287805 8.314472 298.15

n



  

  



n = 58.173 mol/s

(c) CFV molar flow rate. Some CFV flow meters consist of a single venturi and some 

consist of multiple venturis, where different combinations of venturis are used to meter 

different flow rates. If you use multiple venturis and you calibrated each venturi 

independently to determine a separate discharge coefficient, Cd (or calibration coefficient,

Kv), for each venturi, calculate the individual molar flow rates through each venturi and 

sum all their flow rates to determine n . If you use multiple venturis and you calibrated 

each combination of venturis, calculate n using the sum of the active venturi throat areas 

as At, the square root of the sum of the squares of the active venturi throat diameters as dt, 

and the ratio of the venturi throat to inlet diameters as the ratio of the square root of the 

sum of the active venturi throat diameters (dt) to the diameter of the common entrance to 

all the venturis (D).

(1) To calculate the molar flow rate through one venturi or one combination of venturis, 

use its respective mean Cd and other constants you determined according to § 1065.640 

and calculate its molar flow rate n during an emission test, as follows:

t in

d f

mix in

A p n C C

Z M R T



  

  



Eq. 1065.642-4

Example: 

Cd = 0.985

Cf = 0.7219

At = 0.00456 m2

pin = 98.836 kPa = 98836 Pa = 98836 kg/(m∙s2)

Z = 1

Mmix = 28.7805 g/mol = 0.0287805 kg/mol

R = 8.314472 J/(mol·K) = 8.314472 (m2∙kg)/(s2∙mol∙K)

Tin = 378.15 K

0.00456 98836 0.985 0.7219

1 0.0287805 8.314472 378.15

n



  

  



n = 33.690 mol/s

(2) To calculate the molar flow rate through one venturi or a combination of venturis, you 

may use its respective mean, Kv, and other constants you determined according to § 

1065.640 and calculate its molar flow rate n during an emission test. Note that if you 

follow the permissible ranges of dilution air dewpoint versus calibration air dewpoint in 

Table 3 of § 1065.640, you may set Mmix-cal and Mmix equal to 1. Calculate n as follows:
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 872 of 1039

in std mix-cal

in std mix

K p vp M

n

T M T R



  





Eq. 1065.642-5

Where:

stdref in-cal

in-cal

v

V T

K

p





Eq. 1065.642-6

Vstdref = volume flow rate of the standard at reference conditions of 293.15 K and 101.325 

kPa.

Tin-cal = venturi inlet temperature during calibration.

Pin-cal = venturi inlet pressure during calibration.

Mmix-cal = molar mass of gas mixture used during calibration.

Mmix = molar mass of gas mixture during the emission test calculated using Equation 

1065.640-9.

Example: 

Vstdref = 0.4895 m3

Tin-cal = 302.52 K

Pin-cal = 99.654 kPa = 99654 Pa = 99654 kg/(m∙s2)

pin = 98.836 kPa = 98836 Pa = 98836 kg/(m∙s2)

pstd = 101.325 kPa = 101325 Pa = 101325 kg/(m∙s2)

Mmix-cal = 28.9656 g/mol = 0.0289656 kg/mol

Mmix = 28.7805 g/mol = 0.0287805 kg/mol

Tin = 353.15 K

Tstd = 293.15 K

R = 8.314472 J/(mol·K) = 8.314472 (m

2

∙kg)/(s2∙mol∙K)

0.4895 302.52 4 0.5 0.000074954 m s K kg

99654

Kv



   

0.000074954 98936 101325 0.0289656

353.15 293.15 8.314472 0.0287805

n



  





n = 16.457 mol/s

305. Section 1065.644 is revised to read as follows:

§ 1065.644 Vacuum-decay leak rate.

This section describes how to calculate the leak rate of a vacuum-decay leak verification, 

which is described in § 1065.345(e). Use the following equation to calculate the leak 

rate, leak n , and compare it to the criterion specified in § 1065.345(e):

 

2 1

vac 2 1

leak

2 1

p p

V T T

n

R t t

    

 

 




*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 873 of 1039

Eq. 1065.644-1

Where:

Vvac = geometric volume of the vacuum-side of the sampling system.

R = molar gas constant.

p2 = vacuum-side absolute pressure at time t2.

T2 = vacuum-side absolute temperature at time t2.

p1 = vacuum-side absolute pressure at time t1.

T1 = vacuum-side absolute temperature at time t1.

t2 = time at completion of vacuum-decay leak verification test.

t1 = time at start of vacuum-decay leak verification test.

Example:

Vvac = 2.0000 L = 0.00200 m3

R = 8.314472 J/(mol·K) = 8.314472 (m2∙kg)/(s2∙mol∙K)

p2 = 50.600 kPa = 50600 Pa = 50600 kg/(m∙s2)

T2 = 293.15 K

p1 = 25.300 kPa = 25300 Pa = 25300 kg/(m∙s2)

T1 = 293.15 K

t2 = 10:57:35 AM

t1 = 10:56:25 AM

 

leak

50600 25300

0.0002 293.15 293.15

8.314472 10 :57 : 35 10 : 56 : 25

n

    

 

 





leak

0.00200 86.304

8.314472 70

n  

leak n  0.00030 mol/s

306. Section 1065.645 is amended by revising the introductory text and paragraph (a) 

and adding paragraph (d) to read as follows:

§ 1065.645 Amount of water in an ideal gas.

This section describes how to determine the amount of water in an ideal gas, which you 

need for various performance verifications and emission calculations. Use the equation 

for the vapor pressure of water in paragraph (a) of this section or another appropriate 

equation and, depending on whether you measure dewpoint or relative humidity, perform

one of the calculations in paragraph (b) or (c) of this section. Paragraph (d) of this 

section provides an equation for determining dewpoint from relative humidity and dry

bulb temperature measurements. The equations for the vapor pressure of water as 

presented in this section are derived from equations in “Saturation Pressure of Water on 

the New Kelvin Temperature Scale” (Goff, J.A., Transactions American Society of 

Heating and Air-Conditioning Engineers, Vol. 63, No. 1607, pages 347 – 354). Note that 

the equations were originally published to derive vapor pressure in units of atmospheres 

and have been modified to derive results in units of kPa by converting the last term in 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 874 of 1039

each equation.

(a) Vapor pressure of water. Calculate the vapor pressure of water for a given saturation 

temperature condition, Tsat, as follows, or use good engineering judgment to use a 

different relationship of the vapor pressure of water to a given saturation temperature 

condition:

(1) For humidity measurements made at ambient temperatures from (0 to 100) °C, or for 

humidity measurements made over super-cooled water at ambient temperatures from (–

50 to 0) °C, use the following equation:

sat

sat

8.2969 1

sat 4 273.16

10 H2O 10

sat

273.16 4.76955 1

3

273.16 log ( ) 10.79574 1 5.02800 log 1.50475 10 1 10

273.16

0.42873 10 10 1 0.2138602

T

T

T

p

T

 

    

  

 

   

  

     

                     

 

      

 

Eq. 1065.645-1

Where:

pH2O = vapor pressure of water at saturation temperature condition, kPa.

Tsat = saturation temperature of water at measured conditions, K.

Example:

Tsat = 9.5 °C = 282.65 K

282.65 8.2969 1

4 273.16

10 H2O 10

273.16 4.76955 1

3 282.65

273.16 282.65 log ( ) 10.79574 1 5.02800 log 1.50475 10 1 10

282.65 273.16

0.42873 10 10 1 0.2138602

p

 

   

  

 

   

  

     

                   

 

      

 

log10(pH2O) = 0.074297

pH2O = 100.074297 = 1.186581 kPa

(2) For humidity measurements over ice at ambient temperatures from (–100 to 0) °C, use 

the following equation:

10 H2O 10

sat sat

sat

273.16 273.16 log ( ) 9.096853 1 3.566506 log

0.876812 1 0.2138602

273.16

p

T T

T

   

             

 

       

Eq. 1065.645-2

Example:
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 875 of 1039

Tice = –15.4 °C = 257.75 K

10 H2O 10

273.16 273.16 log ( ) 9.096853 1 3.566506 log

257.75 257.75

257.75 0.876812 1 0.2138602

273.16

p

   

             

 

      

log10(pH20) = –0.798207

pH2O = 10–0.79821 = 0.159145 kPa

* * * * *

(d) Dewpoint determination from relative humidity and dry bulb temperature. This 

paragraph (d) describes how to calculate dewpoint temperature from relative humidity, 

RH %. This is based on “ITS-90 Formulations for Vapor Pressure, Frostpoint 

Temperature, Dewpoint Temperature, and Enhancement Factors in the Range –100 to 

+100 °C” (Hardy, B., The Proceedings of the Third International Symposium on 

Humidity & Moisture, Teddington, London, England, April 1998). Calculate pH20sat as 

described in paragraph (a) of this section based on setting Tsat equal to Tamb. Calculate 

pH20scaled by multiplying pH20sat by RH %. Calculate the dewpoint, Tdew, from pH20 using 

the following equation:

     

     

2 3 2 1 1 6

H2O H2O H2O

dew 2 3 1 3 5

H2O H2O H2O

2.0798233 10 2.0156028 10 ln 4.6778925 10 ln 9.2288067 10 ln

1 1.3319669 10 ln 5.6577518 10 ln 7.5172865 10 ln

p p p

T

p p p

 

  

         



        

Eq. 1065.645-5

Where: 

ln(pH2O) = the natural log of pH2Oscaled, which is the water vapor pressure scaled to the 

relative humidity at the location of the relative humidity measurement, Tsat = Tamb.

Example:

RH % = 39.61 %

Tsat = Tamb = 20.00 °C = 293.15K

Using Eq. 1065.645-1,

pH2Osat = 2.3371 kPa

pH2Oscaled = (39.61 %) = 0.925717 kPa = 925.717 Pa

     

     

2 1 1 6 2 3

dew 1 3 2 3 5

2.0798233 10 2.0156028 10 ln 925.717 4.6778925 10 ln 925.717 9.2288067 10 ln 925.717

1 1.3319669 10 ln 925.717 5.6577518 10 ln 925.717 7.5172865 10 ln 925.717

T

 

  

         



        

Tdew = 279.00 K = 5.85 °C

307. Section 1065.650 is amended by revising paragraphs (c)(1)(i), (c)(1)(ii), and (f)(4) 

to read as follows:

§ 1065.650 Emission calculations.

* * * * *

(c) * * *
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 876 of 1039

(1) * * *

(i) Correct all gaseous emission analyzer concentration readings, including continuous 

readings, sample bag readings, and dilution air background readings, for drift as 

described in § 1065.672. Note that you must omit this step where brake-specific 

emissions are calculated without the drift correction for performing the drift validation 

according to § 1065.550(b). When applying the initial THC and CH4 contamination 

readings according to § 1065.520(f), use the same values for both sets of calculations. 

You may also use as-measured values in the initial set of calculations and corrected 

values in the drift-corrected set of calculations as described in § 1065.520(g)(7).

(ii) Correct all THC and CH4 concentrations for initial contamination as described in § 

1065.660(a), including continuous readings, sample bags readings, and dilution air 

background readings.

* * * * *

(f) * * *

(4) Example. The following example shows how to calculate mass of emissions using 

proportional values:

N = 3000

frecord = 5 Hz

efuel = 285 g/(kW∙hr)

wfuel = 0.869 g/g

Mc = 12.0107 g/mol

1

n

 = 3.922 mol/s = 14119.2 mol/hr

xCcombdry1 = 91.634 mmol/mol = 0.091634 mol/mol

xH2Oexh1 = 27.21 mmol/mol = 0.02721 mol/mol

Using Eq. 1065.650-5,

t = 0.2 s

2 Ccombdry2 3000 Ccombdry3000

H2Oexh2 H2Oexh3000

3.922 0.091634 12.0107 ... 0.2

1 0.02721 1 1

285 0.869

n x n x

x x

W

    

     

    





   



W = 5.09 (kW∙hr)

* * * * *

308. Section 1065.655 is amended by revising paragraphs (c) introductory text, (c)(3), 

(d), (e), and (f)(2) to read as follows:

§ 1065.655 Chemical balances of fuel, intake air, and exhaust.

* * * * *

(c) Chemical balance procedure. The calculations for a chemical balance involve a 

system of equations that require iteration. We recommend using a computer to solve this 

system of equations. You must guess the initial values of up to three quantities: the 

amount of water in the measured flow, xH2Oexh, fraction of dilution air in diluted exhaust, 

xdil/exh, and the amount of products on a C1 basis per dry mole of dry measured flow, 

xCcombdry. You may use time-weighted mean values of combustion air humidity and 

dilution air humidity in the chemical balance; as long as your combustion air and dilution 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 877 of 1039

air humidities remain within tolerances of ±0.0025 mol/mol of their respective mean 

values over the test interval. For each emission concentration, x, and amount of water, 

xH2Oexh, you must determine their completely dry concentrations, xdry and xH2Oexhdry. You 

must also use your fuel’s atomic hydrogen-to-carbon ratio, , oxygen-to-carbon ratio, 

sulfur-to-carbon ratio, , and nitrogen-to-carbon ratio, . You may calculate , , , 

and  based on measured fuel composition as described in paragraph (d)(1) or (d)(2) of 

this section, or you may use default values for a given fuel as described in paragraph 

(d)(3) of this section. Use the following steps to complete a chemical balance:

* * * * *

(3) Use the following symbols and subscripts in the equations for this paragraph (c):

xdil/exh = amount of dilution gas or excess air per mole of exhaust.

xH2Oexh = amount of H2O in exhaust per mole of exhaust.

xCcombdry = amount of carbon from fuel in the exhaust per mole of dry exhaust.

xH2dry = amount of H2 in exhaust per amount of dry exhaust.

KH2Ogas = water-gas reaction equilibrium coefficient. You may use 3.5 or calculate your 

own value using good engineering judgment.

xH2Oexhdry = amount of H2O in exhaust per dry mole of dry exhaust.

xprod/intdry = amount of dry stoichiometric products per dry mole of intake air.

xdil/exhdry = amount of dilution gas and/or excess air per mole of dry exhaust.

xint/exhdry = amount of intake air required to produce actual combustion products per mole 

of dry (raw or diluted) exhaust.

xraw/exhdry = amount of undiluted exhaust, without excess air, per mole of dry (raw or 

diluted) exhaust.

xO2int = amount of intake air O2 per mole of intake air.

xCO2intdry = amount of intake air CO2 per mole of dry intake air. You may use xCO2intdry = 

375 μmol/mol, but we recommend measuring the actual concentration in the intake air.

xH2Ointdry = amount of intake air H2O per mole of dry intake air.

xCO2int = amount of intake air CO2 per mole of intake air.

xCO2dil = amount of dilution gas CO2 per mole of dilution gas.

xCO2dildry = amount of dilution gas CO2 per mole of dry dilution gas. If you use air as 

diluent, you may use xCO2dildry = 375 μmol/mol, but we recommend measuring the actual 

concentration in the intake air.

xH2Odildry = amount of dilution gas H2O per mole of dry dilution gas.

xH2Odil = amount of dilution gas H2O per mole of dilution gas.

x[emission]meas = amount of measured emission in the sample at the respective gas analyzer.

x[emission]dry = amount of emission per dry mole of dry sample.

xH2O[emission]meas = amount of H2O in sample at emission-detection location. Measure or 

estimate these values according to § 1065.145(e)(2).

xH2Oint = amount of H2O in the intake air, based on a humidity measurement of intake air.

 = atomic hydrogen-to-carbon ratio of the mixture of fuel(s) being combusted, weighted 

by molar consumption.

 = atomic oxygen-to-carbon ratio of the mixture of fuel(s) being combusted, weighted 

by molar consumption.

 = atomic sulfur-to-carbon ratio of the mixture of fuel(s) being combusted, weighted by 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 878 of 1039

molar consumption.

 = atomic nitrogen-to-carbon ratio of the mixture of fuel(s) being combusted, weighted 

by molar consumption.

* * * * *

(d) Carbon mass fraction and fuel composition. Determine carbon mass fraction of fuel, 

wc, and fuel composition represented by α, β, γ, and δ using one of the following 

methods:

(1) You may calculate wc as described in this paragraph (d)(1) based on measured fuel 

properties. To do so, you must determine values for  and  in all cases, but you may set 

 and  to zero if the default value listed in Table 1 of this section is zero. Calculate wc

using the following equation:

C

c

C H O S N

1

1

M

w

M M   M M   M





        

Eq. 1065.655-19

Where:

[Note to Editor: The following expression for wc is a lower-case omega in the 

Federal Register. It should be an italicized lower-case w.]

wc = carbon mass fraction of fuel.

MC = molar mass of carbon.

 = atomic hydrogen-to-carbon ratio of the mixture of fuel(s) being combusted, weighted 

by molar consumption.

MH = molar mass of hydrogen.

 = atomic oxygen-to-carbon ratio of the mixture of fuel(s) being combusted, weighted 

by molar consumption.

MO = molar mass of oxygen.

 = atomic sulfur-to-carbon ratio of the mixture of fuel(s) being combusted, weighted by 

molar consumption.

MS = molar mass of sulfur.

 = atomic nitrogen-to-carbon ratio of the mixture of fuel(s) being combusted, weighted 

by molar consumption.

MN = molar mass of nitrogen.

Example:

 = 1.8

 = 0.05

 = 0.0003

= 0.0001

MC = 12.0107

MH = 1.00794

MO = 15.9994

MS = 32.065

MN = 14.0067
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 879 of 1039

c

1 12.0107

1 12.0107 1.8 1.00794 0.05 15.9994 0.0003 32.065 0.0001 14.0067

w





        

wc = 0.8206

(2) Determine a fuel’s elemental mass fractions and values for α, β, γ, and δ as follows: 

(i) For gaseous fuels, use the default values for α, β, γ, and δ in Table 1 of this section or 

use good engineering judgment to determine those values based on measurement. 

(ii) Determine mass fractions of liquid fuels as follows:

(A) You may determine the carbon and hydrogen mass fractions according to ASTM 

D5291 (incorporated by reference in § 1065.1010). When using ASTM D5291 to 

determine carbon and hydrogen mass fractions of gasoline (with or without blended 

ethanol), use good engineering judgment to adapt the method as appropriate.

(B) Determine oxygen mass fraction of gasoline (with or without blended ethanol) 

according to ASTM D5599 (incorporated by reference in § 1065.1010). For all other 

liquid fuels, determine the oxygen mass fraction using good engineering judgment.

(C) Determine the nitrogen mass fraction according to ASTM D4629 or ASTM D5762 

(incorporated by reference in § 1065.1010) for all liquid fuels. Select the correct method 

based on the expected nitrogen content.

(D) Determine the sulfur mass fraction according to subpart H of this part.

(iii) For liquid fuels, use the default values for α, β, γ, and δ in Table 1 of this section, or 

you may determine the value for any of these parameters based on measurement. 

Calculate these values using the following equations:

H C

C H

w M

w M









 

Eq. 1065.655-20

O C

C O

w M

w M









Eq. 1065.655-21

S C

C S

w M

w M









Eq. 1065.655-22

N C

C N

w M

w M









Eq. 1065.655-23

Where:

wC = carbon mass fraction of fuel.

wH = hydrogen mass fraction of fuel.

wO = oxygen mass fraction of fuel.

wS = sulfur mass fraction of fuel.

wN = nitrogen mass fraction of fuel.
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

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Example:

wC = 0.8206

wH = 0.1239

wO = 0.0547

wS = 0.00066

wN = 0.000095

MC = 12.0107

MH = 1.00794

MO = 15.9994

MS = 32.065

MN = 14.0067

0.1239 12.0107

0.8206 1.00794









0.0547 12.0107

0.8206 15.9994









0.00066 12.0107

0.8206 32.065









0.000095 12.0107

0.8206 14.0067









 = 1.8

 = 0.05

 = 0.0003

= 0.0001

TABLE 1 OF § 1065.655–DEFAULT VALUES OF , , , , AND wc, FOR VARIOUS FUELS

Fuel

Atomic hydrogen,

oxygen, sulfur, and 

nitrogen-to-carbon ratios

CHαOβSN

Carbon mass 

fraction, wc

g/g

Gasoline CH1.85O0S0N0 0.866

E10 Gasoline CH1.92O0.03S0N0 0.833

E15 Gasoline CH1.95O0.05S0N0 0.817

E85 Gasoline CH2.73O0.38S0N0 0.576

#1 Diesel CH1.93O0S0N0 0.861

#2 Diesel CH1.80O0S0N0 0.869

Liquefied petroleum gas CH2.64O0S0N0 0.819

Natural gas CH3.78 O0.016S0N0 0.747

E100 Ethanol CH3O0.5S0N0 0.521

M100 Methanol CH4O1S0N0 0.375

Residual fuel blends Must be determined by measured fuel properties as 

described in paragraph (d)(1) of this section.
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(e) Calculated raw exhaust molar flow rate from measured intake air molar flow rate or 

fuel mass flow rate. You may calculate the raw exhaust molar flow rate from which you 

sampled emissions, exh n , based on the measured intake air molar flow rate, int n , or the 

measured fuel mass flow rate, mfuel  , and the values calculated using the chemical balance 

in paragraph (c) of this section. The chemical balance must be based on raw exhaust gas 

concentrations. Solve for the chemical balance in paragraph (c) of this section at the 

same frequency that you update and record int n or mfuel  . For laboratory tests, calculating 

raw exhaust molar flow rate using measured fuel mass flow rate is valid only for steadystate testing. See § 1065.915(d)(5)(iv) for application to field testing.

(1) Crankcase flow rate. If engines are not subject to crankcase controls under the 

standard-setting part, you may calculate raw exhaust flow based on int n or mfuel  using one 

of the following:

(i) You may measure flow rate through the crankcase vent and subtract it from the 

calculated exhaust flow.

(ii) You may estimate flow rate through the crankcase vent by engineering analysis as 

long as the uncertainty in your calculation does not adversely affect your ability to show 

that your engines comply with applicable emission standards.

(iii) You may assume your crankcase vent flow rate is zero.

(2) Intake air molar flow rate calculation. Calculate exh n based on int n using the following 

equation:

 

 

int

exh

int/exhdry raw/exhdry

H2Oexhdry

1

1

n

n

x x

x



  

  



 





Eq. 1065.655-24

Where:

exh n = raw exhaust molar flow rate from which you measured emissions.

int n = intake air molar flow rate including humidity in intake air.

Example:

int n = 3.780 mol/s

xint/exhdry = 0.69021 mol/mol

xraw/exhdry = 1.10764 mol/mol

xH20exhdry = 107.64 mmol/mol = 0.10764 mol/mol

 

 

exh

3.780

0.69021 1.10764 1

1 0.10764

n 

  

  

  



exh n = 6.066 mol/s

(3) Fuel mass flow rate calculation. This calculation may be used only for steady-state 

laboratory testing. See § 1065.915(d)(5)(iv) for application to field testing. Calculate 
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exh n based on mfuel  using the following equation:

fuel c H  2Oexhdry 

exh

c Ccombdry

m w 1 x

n

M x

  









Eq. 1065.655-25

Where:

exh n = raw exhaust molar flow rate from which you measured emissions.

mfuel  = fuel mass flow rate.

Example:

mfuel  = 7.559 g/s

wc = 0.869 g/g

MC = 12.0107 g/mol

xCcombdry = 99.87 mmol/mol = 0.09987 mol/mol

xH20exhdry = 107.64 mmol/mol = 0.10764 mol/mol

 

exh

7.559 0.869 1 0.10764

12.0107 0.09987

n

  







exh n = 6.066 mol/s

(f) * * *

(2) Dilute exhaust and intake air molar flow rate calculation. Calculate exh n as follows:

    exh raw/exhdry int/exhdry H2Oexh dexh int n x     x x  1   n n

Eq. 1065.655-26

Example:

int n  7.930 mol/s

raw/exhdry x  0.1544 mol/mol

0.1451 mol/mol xint/exhdry 

H2Oexh x   32.46 mmol/mol 0.03246 mol/mol

dexh n  49.02 mol/s

n

exh   0.1544 0.1451  1 0.03246  49.02 7.930   0.4411 7.930 8  .371 mol/s

309. Section 1065.659 is amended by revising paragraphs (a) and (d) to read as 

follows:

§ 1065.659 Removed water correction.

(a) If you remove water upstream of a concentration measurement, x, correct for the 

removed water. Perform this correction based on the amount of water at the 

concentration measurement, xH2O[emission]meas, and at the flow meter, xH2Oexh, whose flow is 

used to determine the mass emission rate or total mass over a test interval. For 

continuous analyzers downstream of a sample dryer for transient and ramped-modal 
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Page 883 of 1039

cycles, you must apply this correction on a continuous basis over the test interval, even if 

you use one of the options in § 1065.145(e)(2) that results in a constant value for 

xH2O[emission]meas because xH2Oexh varies over the test interval. For batch analyzers, 

determine the flow-weighted average based on the continuous xH2Oexh values determined 

as described in paragraph (c) of this section. For batch analyzers, you may determine the 

flow-weighted average xH2Oexh based on a single value of xH2Oexh determined as described 

in paragraphs (c)(2) and (3) of this section, using flow-weighted average or batch 

concentration inputs.

* * * * *

(d) Perform a removed water correction to the concentration measurement using the 

following equation:

H2Oexh

[emission]meas

H2O[emission]meas

1

1

x

x x

x

  

  

  

Eq. 1065.659-1

Example:

xCOmeas = 29.0 μmol/mol

xH2OCOmeas = 8.601 mmol/mol = 0.008601 mol/mol

xH2Oexh = 34.04 mmol/mol = 0.03404 mol/mol

CO

1 0.03404 29.0

1 0.008601

x

  

     

xCO = 28.3 μmol/mol

310. Section 1065.665 is revised to read as follows:

§ 1065.665 THCE and NMHCE determination.

(a) If you measured an oxygenated hydrocarbon's mass concentration, first calculate its 

molar concentration in the exhaust sample stream from which the sample was taken (raw 

or diluted exhaust), and convert this into a C1-equivalent molar concentration. Add these 

C1-equivalent molar concentrations to the molar concentration of non-oxygenated total 

hydrocarbon (NOTHC). The result is the molar concentration of total hydrocarbon 

equivalent (THCE). Calculate THCE concentration using the following equations, noting 

that Eq. 1065.665-3 is required only if you need to convert your oxygenated hydrocarbon 

(OHC) concentration from mass to moles:

  THCE NOTHC OHCi OHCi-init

1

N

i

x x x x



  

Eq. 1065.665-1

NOTHC THC[THC-FID]cor  OHCi OHCi-init  OHCi[THC-FID] 

1

N

i

x x x x RF



   

Eq. 1065.665-2
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Page 884 of 1039

dexhOHCi

OHCi dexhOHCi

OHCi

dexh dexh

dexh

m

M n

x

m n

M

 

Eq. 1065.665-3

Where:

xTHCE = The sum of the C1-equivalent concentrations of non-oxygenated hydrocarbons, 

alcohols, and aldehydes.

xNOTHC = The sum of the C1-equivalent concentrations of NOTHC.

xOHCi = The C1-equivalent concentration of oxygenated species i in diluted exhaust, not 

corrected for initial contamination.

xOHCi-init = The C1-equivalent concentration of the initial system contamination (optional) 

of oxygenated species i, dry-to-wet corrected. 

xTHC[THC-FID]cor = The C1-equivalent response to NOTHC and all OHC in diluted exhaust, 

HC contamination and dry-to-wet corrected, as measured by the THC-FID.

RFOHCi[THC-FID] = The response factor of the FID to species i relative to propane on a C1-

equivalent basis.

C

#

= the mean number of carbon atoms in the particular compound.

Mdexh = The molar mass of diluted exhaust as determine in § 1065.340.

mdexhOHCi = The mass of oxygenated species i in dilute exhaust.

MOHCi = The C1-equivalent molecular weight of oxygenated species i.

mdexh = The mass of diluted exhaust

ndexhOHCi = The number of moles of oxygenated species i in total diluted exhaust flow.

ndexh = The total diluted exhaust flow.

(b) If we require you to determine nonmethane hydrocarbon equivalent (NMHCE), use 

the following equation:

xNMHCE = xTHCE – RFCH4[THC-FID]  xCH4

Eq. 1065.665-4

Where:

xNMHCE = The sum of the C1-equivalent concentrations of nonoxygenated nonmethane 

hydrocarbon (NONMHC), alcohols, and aldehydes.

RFCH4[THC-FID] = response factor of THC-FID to CH4.

xCH4 = concentration of CH4, HC contamination (optional) and dry-to-wet corrected, as 

measured by the gas chromatograph FID.

(c) The following example shows how to determine NMHCE emissions based on ethanol 

(C2H5OH), methanol (CH3OH), acetaldehyde (C2H4O), and formaldehyde (CH2O) as C1-

equivalent molar concentrations:

xTHC[THC-FID]cor = 145.6 μmol/mol

xCH4 = 18.9 μmol/mol

xC2H5OH = 100.8 μmol/mol

xCH3OH = 1.1 μmol/mol

xC2H4O = 19.1 μmol/mol
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 885 of 1039

xCH2O = 1.3 μmol/mol

RFCH4[THC-FID] = 1.07

RFC2H5OH[THC-FID] = 0.76

RFCH3OH[THC-FID] = 0.74

RFH2H4O[THC-FID] = 0.50

RFCH2O[THC-FID] = 0.0

xNMHCE = xTHC[THC-FID]cor – (xC2H5OH  RFC2H5OH[THC-FID] + xCH3OH  RFCH3OH[THC-FID] + 

xC2H4O  RFC2H4O[THC-FID] + xCH2O  RFCH2O[THC-FID] + xC2H5OH + xCH3OH + xC2H4O + xCH2O –

(RFCH4[THC-FID]  xCH4)

xNMHCE = 145.6 – (100.8 ∙ 0.76 + 1.1  0.74 + 19.1  0.50 + 1.3  0+ 100.8 + 1.1 + 19.1 + 

1.3 – (1.07  18.9)

xNMHCE = 160.71 μmol/mol

311. Section 1065.690 is amended by revising paragraph (e) to read as follows:

§ 1065.690 Buoyancy correction for PM sample media.

* * * * *

(e) Correction calculation. Correct the PM sample media for buoyancy using the 

following equations:

air

weight

cor uncor

air

media

1

1

m m









 

  

  

 



   

Eq. 1065.690-1

Where:

mcor = PM mass corrected for buoyancy.

muncor = PM mass uncorrected for buoyancy.

air = density of air in balance environment.

weight = density of calibration weight used to span balance.

media = density of PM sample media, such as a filter.

abs mix

air

amb

p M

R T









Eq. 1065.690-2

Where:

pabs = absolute pressure in balance environment.

Mmix = molar mass of air in balance environment.

R = molar gas constant.

Tamb = absolute ambient temperature of balance environment.

Example:
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pabs = 99.980 kPa

Tsat = Tdew = 9.5 °C

Using Eq. 1065.645-1,

pH20 = 1.1866 kPa

Using Eq. 1065.645-3,

xH2O = 0.011868 mol/mol

Using Eq. 1065.640-9,

Mmix = 28.83563 g/mol

R = 8.314472 J/(mol·K)

Tamb = 20 °C

air

99.980 28.83563

8.314472 293.15









air = 1.18282 kg/m3

muncorr = 100.0000 mg

weight = 8000 kg/m3

media = 920 kg/m3

cor

1.18282 1

8000 100.0000 1.18282 1

920

m

 

  

  

  

 

mcor = 100.1139 mg

312. Section 1065.695 is amended by revising paragraph (c)(4)(i) and adding 

paragraph (c)(6)(x) to read as follows:

§ 1065.695 Data requirements.

* * * * *

(c) * * *

(4) * * *

(i) Linearity verification.

* * * * *

(6) * * *

(x) Number and type of preconditioning cycles.

* * * * *

Subpart H—[Amended]

313. Section 1065.701 is amended by revising paragraphs (a), (d), and (f) to read as 

follows:

§ 1065.701 General requirements for test fuels.

(a) General. For all emission measurements, use test fuels that meet the specifications in 

this subpart, unless the standard-setting part directs otherwise. Section 1065.10(c)(1) 

does not apply with respect to test fuels. Note that the standard-setting parts generally 

require that you design your emission controls to function properly when using 

commercially available fuels, even if they differ from the test fuel. Where we specify
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 887 of 1039

multiple grades of a certain fuel type (such as diesel fuel with different sulfur 

concentrations), see the standard-setting part to determine which grade to use.

* * * * *

(d) Fuel specifications. Specifications in this section apply as follows:

(1) Measure and calculate values as described in the appropriate reference procedure. 

Record and report final values expressed to at least the same number of decimal places as 

the applicable limit value. The right-most digit for each limit value is significant unless 

specified otherwise. For example, for a specified distillation temperature of 60 °C, 

determine the test fuel’s value to at least the nearest whole number. 

(2) The fuel parameters specified in this subpart depend on measurement procedures that 

are incorporated by reference. For any of these procedures, you may instead rely upon 

the procedures identified in 40 CFR part 80 for measuring the same parameter. For 

example, we may identify different reference procedures for measuring gasoline 

parameters in 40 CFR 80.46.

* * * * *

(f) Service accumulation and field testing fuels. If we do not specify a serviceaccumulation or field-testing fuel in the standard-setting part, use an appropriate 

commercially available fuel such as those meeting minimum specifications from the 

following table:

TABLE 1 OF § 1065.701–EXAMPLES OF SERVICE-ACCUMULATION AND FIELD-TESTING 

FUELS

Fuel category Subcategory Reference procedure1

Diesel

Light distillate and light blends with 

residual ASTM D975

Middle distillate ASTM D6985

Biodiesel (B100) ASTM D6751

Intermediate and residual fuel All See § 1065.705

Gasoline

Automotive gasoline ASTM D4814

Automotive gasoline with ethanol 

concentration up to 10 volume %. ASTM D4814

Alcohol Ethanol (E51-83) ASTM D5798

Methanol (M70-M85) ASTM D5797

Aviation fuel

Aviation gasoline ASTM D910

Gas turbine ASTM D1655

Jet B wide cut ASTM D6615

Gas turbine fuel General ASTM D2880

1ASTM specifications are incorporated by reference in § 1065.1010.

314. Section 1065.703 is amended by revising paragraph (b) and Table 1 to read as 

follows:

§ 1065.703 Distillate diesel fuel.

* * * * *

(b) There are three grades of #2 diesel fuel specified for use as a test fuel. See the 

standard-setting part to determine which grade to use. If the standard-setting part does 

not specify which grade to use, use good engineering judgment to select the grade that 

represents the fuel on which the engines will operate in use. The three grades are 

specified in the following table:
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TABLE 1 OF § 1065.703–TEST FUEL SPECIFICATIONS FOR DISTILLATE DIESEL FUEL

Property Unit Ultra Low

Sulfur

Low

Sulfur

High

Sulfur

Reference

Procedure1

Cetane Number — 40 - 50 40 - 50 40 - 50 ASTM D613

Distillation range:

Initial boiling point

10 pct. point 

50 pct. point

90 pct. point 

Endpoint

°C

171 - 204

204 - 238

243 - 282

293 - 332

321 - 366

171 - 204

204 - 238

243 - 282

293 - 332

321 - 366

171 - 204

204 - 238

243 - 282

293 - 332

321 - 366

ASTM D86

Gravity °API 32 - 37 32 - 37 32 - 37 ASTM D4052

Total sulfur, ultra low sulfur mg/kg 7 – 15 See 40 CFR 80.580

Total sulfur, low and high sulfur mg/kg 300 - 500 800 - 2500 ASTM D2622or 

alternates as allowed 

under 40 CFR 80.580

Aromatics, min. (Remainder shall be 

paraffins, naphthenes, and olefins)

g/kg 100 100 100 ASTM D5186

Flashpoint, min. °C 54 54 54 ASTM D93

Kinematic Viscosity cSt 2.0 - 3.2 2.0 - 3.2 2.0 - 3.2 ASTM D445

1ASTM procedures are incorporated by reference in § 1065.1010. See § 1065.701(d) for other allowed procedures.

* * * * *

315. Section 1065.705 is revised to read as follows:

§ 1065.705 Residual and intermediate residual fuel.

This section describes the specifications for fuels meeting the definition of residual fuel 

in 40 CFR 80.2, including fuels marketed as intermediate fuel. Residual fuels for service 

accumulation and any testing must meet the following specifications:

(a) The fuel must be a commercially available fuel that is representative of the fuel that 

will be used by the engine in actual use. 

(b) The fuel must be free of used lubricating oil. Demonstrate this by showing that the 

fuel meets at least one of the following specifications.

(1) Zinc is at or below 15 mg per kg of fuel based on the procedures specified in IP470, 

IP501, or ISO 8217 (incorporated by reference in § 1065.1010).

(2) Phosphorus is at or below 15 mg per kg of fuel based on the procedures specified in 

IP500, IP501, or ISO 8217 (incorporated by reference in § 1065.1010).

(3) Calcium is at or below 30 mg per kg of fuel based on the procedures specified in 

IP470, IP501, or ISO 8217 (incorporated by reference in § 1065.1010).

(c) The fuel must meet the specifications for one of the categories in the following table:
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TABLE 1 OF § 1065.705–SERVICE ACCUMULATION AND TEST FUEL SPECIFICATIONS FOR RESIDUAL FUEL

Property Unit

Category ISO-F- Reference Procedure 1

RMA

30

RMB

30

RMD

80

RME

180

RMF

180

RMG

380

RMH

380

RMK

380

RMH

700

RMK

700

Density at 15 °C, max. kg/m3960.0 975.0 980.0 991.0 991.0 1010.0 991.0 1010.0 ISO 3675 or ISO 12185 (see 

also ISO 8217)

Kinematic viscosity at

50 °C, max. cSt 30.0 80.0 180.0 380.0 700.0 ISO 3104

Flash point, min. °C 60 60 60 60 60 ISO 2719 (see also ISO 8217)

Pour point (upper)

Winter quality, max.

Summer quality, max.

°C 0

6

24

24

30

30

30

30

30

30

30

30 ISO 3016

Carbon residue, max. (kg/kg) % 10 14 15 20 18 22 22 ISO 10370

Ash, max. (kg/kg) % 0.10 0.10 0.10 0.15 0.15 0.15 ISO 6245

Water, max. (m3/m3) % 0.5 0.5 0.5 0.5 0.5 ISO 3733

Sulfur, max. (kg/kg) % 3.50 4.00 4.50 4.50 4.50 ISO 8754 or ISO 14596 (see 

also ISO 8217)

Vanadium, max. mg/kg 150 350 200 500 300 600 600 ISO 14597 or IP 501 or IP 470 

(see also ISO 8217)

Total sediment 

potential, max. (kg/kg) % 0.10 0.10 0.10 0.10 0.10 ISO 10307-2 (see also ISO 8217)

Aluminium plus 

silicon, max. mg/kg 80 80 80 80 80 ISO 10478 or IP 501 or IP 470 (see also ISO 8217:2012)

1

ISO procedures are incorporated by reference in § 1065.1010. See § 1065.701(d) for other allowed procedures.
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316. Section 1065.710 is revised to read as follows:

§ 1065.710 Gasoline.

(a) This section specifies test fuel properties for gasoline with ethanol (low-level blend 

only) and for gasoline without ethanol. Note that the “fuel type” for the fuels specified in 

paragraphs (b) and (c) of this section is considered to be gasoline. In contrast, fuels with 

higher ethanol concentrations, such as fuel containing 82 percent ethanol, are considered 

to be ethanol fuels rather than gasoline. We specify some test fuel parameters that apply

uniquely for low-temperature testing and for testing at altitudes above 1,219 m. For all 

other testing, use the test fuel parameters specified for general testing. Unless the 

standard-setting part specifies otherwise, use the fuel specified in paragraph (c) of this 

section for general testing. 

(b) The following specifications apply for a blended gasoline test fuel that has nominally

10 % ethanol (commonly called E10 test fuel):

(1) Prepare the blended test fuel from typical refinery gasoline blending components. 

You may not use pure compounds, except as follows:

(i) You may use neat ethanol as a blendstock.

(ii) You may adjust the test fuel’s vapor pressure by adding butane.

(iii) You may adjust the test fuel’s benzene content by adding benzene.

(iv) You may adjust the test fuel’s sulfur content by adding sulfur compounds that are 

representative of those found with in-use fuels.

(2) Table 1 of this section identifies limit values consistent with the units in the reference 

procedure for each fuel property. These values are generally specified in international 

units. Values presented in parentheses are for information only. Table 1 follows:
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TABLE 1 OF § 1065.710–TEST FUEL SPECIFICATIONS FOR A LOW-LEVEL ETHANOLGASOLINE BLEND

Property Unit

SPECIFICATION

Reference Procedure1

General 

Testing

LowTemperature 

Testing

High Altitude 

Testing

Antiknock Index (R+M)/2 - 87.0 - 88.42 87.0 

Minimum ASTM D2699 and D2700

Sensitivity (R-M) - 7.5 Minimum ASTM D2699 and D2700

Dry Vapor Pressure Equivalent 

(DVPE)

3,4 kPa (psi) 60.0-63.4 

(8.7-9.2)

77.2-81.4

(11.2-11.8)

52.4-55.2 

(7.6-8.0) ASTM D5191

Distillation 4

10% evaporated °C (°F) 49-60(120-140)

43-54 

(110-130)

49-60

(120-140)

ASTM D86

50% evaporated °C (°F) 88-99 (190-210)

90% evaporated °C (°F) 157-168 (315-335)

Evaporated final boiling point °C (°F) 193-216 (380-420)

Residue milliliter 2.0 Maximum

Total Aromatic Hydrocarbons volume % 21.0-25.0

ASTM D5769

C6 Aromatics (benzene) volume % 0.5-0.7

C7 Aromatics (toluene) volume % 5.2-6.4

C8 Aromatics volume % 5.2-6.4

C9 Aromatics volume % 5.2-6.4

C10+ Aromatics volume % 4.4-5.6

Olefins5 mass % 4.0-10.0 ASTM D6550

Ethanol blended volume % 9.6-10.0 See paragraph (b)(3) of this section.

Ethanol confirmatory6volume % 9.4-10.2 ASTM D4815 or D5599

Total Content of Oxygenates 

Other than Ethanol 6 volume % 0.1 Maximum ASTM D4815 or D5599

Sulfur mg/kg 8.0-11.0 ASTM D2622, D5453 or D7039

Lead g/liter 0.0026 Maximum ASTM D3237

Phosphorus g/liter 0.0013 Maximum ASTM D3231

Copper Corrosion - No. 1 Maximum ASTM D130

Solvent-Washed Gum Content mg/100 

milliliter 3.0 Maximum ASTM D381

Oxidation Stability minute 1000 Minimum ASTM D525

1ASTM procedures are incorporated by reference in § 1065.1010. See § 1065.701(d) for other allowed procedures.

2Octane specifications apply only for testing related to exhaust emissions. For engines or vehicles that require the use of premium fuel, as 

described in paragraph (d) of this section, the adjusted specification for antiknock index is a minimum value of 91.0; no maximum value 

applies. All other specifications apply for this high-octane fuel.

3Calculate dry vapor pressure equivalent, DVPE, based on the measured total vapor pressure, pT, using the following equation: DVPE (kPa) = 

0.956∙pT - 2.39 or DVPE (psi) = 0.956∙pT – 0.347. DVPE is intended to be equivalent to Reid Vapor Pressure using a different test method.

4

Parenthetical values are shown for informational purposes only. 

5The reference procedure prescribes measurement of olefin concentration in mass %. Multiply this result by 0.857 and round to the first 
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decimal place to determine the olefin concentration in volume %. 

6ASTM D5599 prescribes concentration measurements for ethanol and other oxygenates in mass %. Convert results to volume % as 

specified in Section 14.3 of ASTM D4815.

(3) The ethanol-blended specification in Table 1 of this section is based on the volume % 

ethanol content of the fuel as determined during blending by the fuel supplier and as 

stated by the supplier at the time of fuel delivery. Use good engineering judgment to 

determine the volume % of ethanol based on the volume of each blendstock. We 

recommend using a flow-based or gravimetric procedure that has an accuracy and 

repeatability of ± 0.1 %.

(c) The specifications of this paragraph (c) apply for testing with neat gasoline. This is 

sometimes called indolene or E0 test fuel. Gasoline for testing must have octane values 

that represent commercially available fuels for the appropriate application. Test fuel 

specifications apply as follows:

TABLE 2 OF § 1065.710–TEST FUEL SPECIFICATIONS FOR NEAT (E0) GASOLINE

Property Unit

SPECIFICATION Reference 

Procedure1 General Testing Low-Temperature 

Testing

Distillation Range:

Evaporated initial boiling point

10% evaporated

50% evaporated

90% evaporated

Evaporated final boiling point

°C 24 - 352

49 - 57

93 - 110

149 - 163

Maximum, 213

24 - 36

37 - 48

82 – 101

158 - 174

Maximum, 212

ASTM D86

Hydrocarbon composition:

Olefins

Aromatics

Saturates

volume % Maximum, 0.10

Maximum, 0.35

Remainder

Maximum, 0.175

Maximum, 0.304

Remainder

ASTM D1319

Lead g/liter Maximum, 0.013 Maximum, 0.013 ASTM D3237

Phosphorous g/liter Maximum, 0.0013 Maximum, 0.005 ASTM D3231

Total sulfur mg/kg Maximum, 80 Maximum, 80 ASTM D2622

Dry vapor pressure equivalent3kPa 60.0 - 63.42,4 77.2 - 81.4 ASTM D5191

1ASTM procedures are incorporated by reference in § 1065.1010. See § 1065.701(d) for other allowed 

procedures.

2

For testing at altitudes above 1219 m, the specified initial boiling point range is (23.9 to 40.6) °C and the 

specified volatility range is (52.0 to 55.2) kPa.

3Calculate dry vapor pressure equivalent, DVPE, based on the measured total vapor pressure, pT, in kPa using the

following equation: DVPE (kPa) = 0.956∙pT - 2.39 or DVPE (psi) = 0.956∙pT – 0.347. DVPE is intended to be 

equivalent to Reid Vapor Pressure using a different test method.
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4

For testing unrelated to evaporative emissions, the specified range is (55.2 to 63.4) kPa.

(d) Use the high-octane gasoline specified in paragraph (b) of this section only for 

engines or vehicles for which the manufacturer conditions the warranty on the use of 

premium gasoline.

317. Section 1065.715 is amended by revising paragraph (a) to read as follows:

§ 1065.715 Natural gas.

(a) Except as specified in paragraph (b) of this section, natural gas for testing must meet 

the specifications in the following table:

TABLE 1 OF § 1065.715–TEST FUEL SPECIFICATIONS FOR NATURAL GAS

Property Value1

Methane, CH4 Minimum, 0.87 mol/mol

Ethane, C2H6 Maximum, 0.055 mol/mol

Propane, C3H8 Maximum, 0.012 mol/mol

Butane, C4H10 Maximum, 0.0035 mol/mol

Pentane, C5H12 Maximum, 0.0013 mol/mol

C6 and higher Maximum, 0.001 mol/mol

Oxygen Maximum, 0.001 mol/mol

Inert gases (sum of CO2 and N2) Maximum, 0.051 mol/mol

1 Demonstrate compliance with fuel specifications based on the reference procedures in 

ASTM D1945 (incorporated by reference in § 1065.1010), or on other measurement 

procedures using good engineering judgment. See § 1065.701(d) for other allowed 

procedures.

* * * * *

318. Section 1065.720 is amended by revising paragraph (a) to read as follows:

§ 1065.720 Liquefied petroleum gas.

(a) Except as specified in paragraph (b) of this section, liquefied petroleum gas for testing 

must meet the specifications in the following table:

TABLE 1 OF § 1065.720–TEST FUEL SPECIFICATIONS FOR LIQUEFIED PETROLEUM GAS

Property Value Reference Procedure1

Propane, C3H8 Minimum, 0.85 m3/m3 ASTM D2163

Vapor pressure at 38 °C Maximum, 1400 kPa ASTM D1267or D25982

Volatility residue (evaporated temperature, 35 °C) Maximum, -38 °C ASTM D1837

Butanes Maximum, 0.05 m3/m3 ASTM D2163

Butenes Maximum, 0.02 m3/m3 ASTM D2163

Pentenes and heavier Maximum, 0.005 m3/m3 ASTM D2163

Propene Maximum, 0.1 m3/m3 ASTM D2163

Residual matter (residue on evaporation of 100 ml oil stain 

observation)

Maximum, 0.05 ml pass3 ASTM D2158

Corrosion, copper strip Maximum, No. 1 ASTM D1838

Sulfur Maximum, 80 mg/kg ASTM D2784

Moisture content pass ASTM D2713

1ASTM procedures are incorporated by reference in § 1065.1010. See § 1065.701(d) for other allowed procedures.

2

If these two test methods yield different results, use the results from ASTM D1267.

3The test fuel must not yield a persistent oil ring when you add 0.3 ml of solvent residue mixture to a filter paper in 0.1 

ml increments and examine it in daylight after two minutes.

* * * * *
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319. A new § 1065.725 is added to subpart H to read as follows:

§ 1065.725 High-level ethanol-gasoline blends.

For testing vehicles capable of operating on a high-level ethanol-gasoline blend, create a 

test fuel as follows:

(a) Add ethanol to an E10 fuel meeting the specifications described in § 1065.710 until 

the ethanol content of the blended fuel is between 80 and 83 volume %. 

(b) You may alternatively add ethanol to a gasoline base fuel with no ethanol if you can 

demonstrate that such a base fuel blended with the proper amount of ethanol would meet 

all the specifications for E10 test fuel described in § 1065.710, other than the ethanol 

content.

(c) The ethanol used for blending must be either denatured ethanol meeting the 

specifications in 40 CFR 80.1610, or fuel-grade ethanol with no denaturant. Account for 

the volume of any denaturant when calculating volumetric percentages.

(d) The blended test fuel must have a dry vapor pressure equivalent between 41.5 and 

45.1 kPa (6.0 and 6.5 psi) when measured using the procedure specified in § 1065.710. 

You may add commercial grade butane as needed to meet this specification.

320. Section 1065.750 is amended by revising the introductory text and paragraph (a) 

to read as follows:

§ 1065.750 Analytical Gases.

Analytical gases must meet the accuracy and purity specifications of this section, unless 

you can show that other specifications would not affect your ability to show that you 

comply with all applicable emission standards.

(a) Subparts C, D, F, and J of this part refer to the following gas specifications:

(1) Use purified gases to zero measurement instruments and to blend with calibration 

gases. Use gases with contamination no higher than the highest of the following values 

in the gas cylinder or at the outlet of a zero-gas generator:

(i) 2 % contamination, measured relative to the flow-weighted mean concentration 

expected at the standard. For example, if you would expect a flow-weighted CO 

concentration of 100.0 mol/mol, then you would be allowed to use a zero gas with CO 

contamination less than or equal to 2.000 mol/mol.

(ii) Contamination as specified in the following table:

TABLE 1 OF § 1065.750–GENERAL SPECIFICATIONS FOR PURIFIED GASES1

Constituent Purified Air Purified N2

THC (C1-equivalent) ≤ 0.05 mol/mol ≤ 0.05 mol/mol

CO ≤ 1 mol/mol ≤ 1 mol/mol

CO2 ≤ 10 mol/mol ≤ 10 mol/mol

O2 0.205 to 0.215 mol/mol ≤ 2 mol/mol

NOx ≤ 0.02 mol/mol ≤ 0.02 mol/mol

N2O

2

≤ 0.02 mol/mol ≤ 0.02 mol/mol

1We do not require these levels of purity to be NIST-traceable.

2The N2O limit applies only if the standard-setting part requires you to report N2O or certify to an N2O 

standard.
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(2) Use the following gases with a FID analyzer:

(i) FID fuel. Use FID fuel with a stated H2 concentration of (0.39 to 0.41) mol/mol, 

balance He or N2, and a stated total hydrocarbon concentration of 0.05 mol/mol or less. 

For GC-FIDs that measure methane (CH4) using a FID fuel that is balance N2, perform 

the CH4 measurement as described in SAE J1151 (incorporated by reference in § 

1065.1010).

(ii) FID burner air. Use FID burner air that meets the specifications of purified air in 

paragraph (a)(1) of this section. For field testing, you may use ambient air.

(iii) FID zero gas. Zero flame-ionization detectors with purified gas that meets the 

specifications in paragraph (a)(1) of this section, except that the purified gas O2

concentration may be any value. Note that FID zero balance gases may be any

combination of purified air and purified nitrogen. We recommend FID analyzer zero 

gases that contain approximately the expected flow-weighted mean concentration of O2

in the exhaust sample during testing.

(iv) FID propane span gas. Span and calibrate THC FID with span concentrations of 

propane, C3H8. Calibrate on a carbon number basis of one (C1). For example, if you use 

a C3H8 span gas of concentration 200 mol/mol, span a FID to respond with a value of 

600 mol/mol. Note that FID span balance gases may be any combination of purified air 

and purified nitrogen. We recommend FID analyzer span gases that contain 

approximately the flow-weighted mean concentration of O2 expected during testing. If 

the expected O2 concentration in the exhaust sample is zero, we recommend using a 

balance gas of purified nitrogen.

(v) FID CH4 span gas. If you always span and calibrate a CH4 FID with a nonmethane 

cutter, then span and calibrate the FID with span concentrations of CH4. Calibrate on a 

carbon number basis of one (C1). For example, if you use a CH4 span gas of 

concentration 200 mol/mol, span a FID to respond with a value of 200 mol/mol. Note 

that FID span balance gases may be any combination of purified air and purified 

nitrogen. We recommend FID analyzer span gases that contain approximately the 

expected flow-weighted mean concentration of O2 in the exhaust sample during testing. 

If the expected O2 concentration in the exhaust sample is zero, we recommend using a 

balance gas of purified nitrogen.

(3) Use the following gas mixtures, with gases traceable within ±1 % of the NISTaccepted value or other gas standards we approve:

(i) CH4, balance purified air and/or N2 (as applicable).

(ii) C2H6, balance purified air and/or N2 (as applicable).

(iii) C3H8, balance purified air and/or N2 (as applicable).

(iv) CO, balance purified N2.

(v) CO2, balance purified N2.

(vi) NO, balance purified N2.

(vii)) NO2, balance purified air.

(viii) O2, balance purified N2.

(ix) C3H8, CO, CO2, NO, balance purified N2.

(x) C3H8, CH4, CO, CO2, NO, balance purified N2.
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(xi) N2O, balance purified air and/or N2 (as applicable).

(4) You may use gases for species other than those listed in paragraph (a)(3) of this 

section (such as methanol in air, which you may use to determine response factors), as 

long as they are traceable to within ±3 % of the NIST-accepted value or other similar 

standards we approve, and meet the stability requirements of paragraph (b) of this 

section.

(5) You may generate your own calibration gases using a precision blending device, such 

as a gas divider, to dilute gases with purified N2 or purified air. If your gas divider meets 

the specifications in § 1065.248, and the gases being blended meet the requirements of 

paragraphs (a)(1) and (3) of this section, the resulting blends are considered to meet the 

requirements of this paragraph (a).

* * * * *

Subpart I—[Amended]

321. Section 1065.805 is amended by revising paragraphs (d) and (f) to read as 

follows:

§ 1065.805 Sampling system.

* * * * *

(d) You may bubble a sample of the exhaust through water to collect alcohols for later 

analysis. You may also use a photoacoustic analyzer to quantify ethanol and methanol in 

an exhaust sample as described in § 1065.269.

* * * * *

(f) You may sample alcohols or carbonyls using "California Non-Methane Organic Gas 

Test Procedures" (incorporated by reference in § 1065.1010). If you use this method, 

follow its calculations to determine the mass of the alcohol/carbonyl in the exhaust 

sample, but follow subpart G of this part for all other calculations (40 CFR part 1066, 

subpart G, for vehicle testing).

* * * * *

322. Section 1065.845 is revised to read as follows:

§ 1065.845 Response factor determination. 

Since FID analyzers generally have an incomplete response to alcohols and carbonyls, 

determine each FID analyzer’s alcohol/carbonyl response factor (RFOHCi[THC-FID]) after 

FID optimization to subtract those responses from the FID reading. Use the most 

recently determined alcohol/carbonyl response factors to compensate for 

alcohol/carbonyl response. You are not required to determine the response factor for a 

compound unless you will subtract its response to compensate for a response.

(a) You may generate response factors as described in paragraph (b) of this section, or 

you may use the following default response factors, consistent with good engineering 

judgment:
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TABLE 1 OF § 1065.845–DEFAULT VALUES FOR THC FID

RESPONSE FACTOR RELATIVE TO PROPANE ON A C1-EQUIVALENT BASIS

Compound Response factor (RF)

acetaldehyde 0.50

ethanol 0.75

formaldehyde 0.00

methanol 0.63

propanol 0.85

(b) Determine the alcohol/carbonyl response factors as follows:

(1) Select a C3H8 span gas that meets the specifications of § 1065.750. Note that FID 

zero and span balance gases may be any combination of purified air or purified nitrogen 

that meets the specifications of § 1065.750. We recommend FID analyzer zero and span 

gases that contain approximately the flow-weighted mean concentration of O2 expected 

during testing. Record the C3H8 concentration of the gas.

(2) Select or prepare an alcohol/carbonyl calibration gas that meets the specifications of § 

1065.750 and has a concentration typical of the peak concentration expected at the 

hydrocarbon standard. Record the calibration concentration of the gas.

(3) Start and operate the FID analyzer according to the manufacturer’s instructions.

(4) Confirm that the FID analyzer has been calibrated using C3H8. Calibrate on a carbon 

number basis of one (C1). For example, if you use a C3H8 span gas of concentration 200 

mol/mol, span the FID to respond with a value of 600 mol/mol.

(5) Zero the FID. Note that FID zero and span balance gases may be any combination of 

purified air or purified nitrogen that meets the specifications of § 1065.750. We 

recommend FID analyzer zero and span gases that contain approximately the flowweighted mean concentration of O2 expected during testing.

(6) Span the FID with the C3H8 span gas that you selected under paragraph (a)(1) of this 

section.

(7) Introduce at the inlet of the FID analyzer the alcohol/carbonyl calibration gas that you 

selected under paragraph (a)(2) of this section.

(8) Allow time for the analyzer response to stabilize. Stabilization time may include time 

to purge the analyzer and to account for its response.

(9) While the analyzer measures the alcohol/carbonyl concentration, record 30 seconds of 

sampled data. Calculate the arithmetic mean of these values.

(10) Divide the mean measured concentration by the recorded span concentration of the 

alcohol/carbonyl calibration gas on a C1-equivalent basis. The result is the FID 

analyzer’s response factor for alcohol/carbonyl, RFOHCi[THC-FID] on a C1-equivalent basis.

(c) Alcohol/carbonyl calibration gases must remain within ±2 % of the labeled 

concentration. You must demonstrate the stability based on a quarterly measurement 

procedure with a precision of ±2 % percent or another method that we approve. Your 

measurement procedure may incorporate multiple measurements. If the true 
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concentration of the gas changes deviates by more than ±2 %, but less than ±10 %, the 

gas may be relabeled with the new concentration.

323. Section 1065.850 is revised to read as follows:

§ 1065.850 Calculations.

Use the calculations specified in § 1065.665 to determine THCE or NMHCE and the 

calculations specified in 40 CFR 1066.635 to determine NMOG.

Subpart J—[Amended]

324. Section 1065.905 is amended by revising paragraphs (a) and (d)(2)(i)(A) to read 

as follows:

§ 1065.905 General provisions.

(a) General. Unless the standard-setting part specifies deviations from the provisions of 

this subpart, field testing and laboratory testing with PEMS must conform to the 

provisions of this subpart. Use good engineering judgment when testing with PEMS to 

ensure proper function of the instruments under test conditions. For example, this may

require additional maintenance or calibration for field testing or may require verification 

after moving the PEMS unit.

(d) * * *

(2) * * *

(i) * * *

(A) Use good engineering judgment to control dilution air temperature. If you choose to 

directly and actively control dilution air temperature, set the temperature to 25 °C.

* * * * *

325. Section 1065.915 is amended by revising paragraph (a) to read as follows:

§ 1065.915 PEMS instruments.

(a) Instrument specifications. We recommend that you use PEMS that meet the 

specifications of subpart C of this part. For unrestricted use of PEMS in a laboratory or 

similar environment, use a PEMS that meets the same specifications as each lab 

instrument it replaces. For field testing or for testing with PEMS in a laboratory or 

similar environment, under the provisions of § 1065.905(b), the specifications in the 

following table apply instead of the specifications in Table 1 of § 1065.205.
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TABLE 1 OF § 1065.915–RECOMMENDED MINIMUM PEMS MEASUREMENT INSTRUMENT PERFORMANCE

Measurement Measured 

quantity symbol

Rise time, t10-90, 

and

Fall time, t90-10

Recording update 

frequency Accuracy1 Repeatability1 Noise1

Engine speed transducer fn 1 s 1 Hz means 5 % of pt. or

1 % of max.

2 % of pt. or

1 % of max. 0.5 % of max

Engine torque estimator, BSFC

(This is a signal from an engine’s ECM) T or BSFC 1 s 1 Hz means 8 % of pt. or5 % of max.

2 % of pt. or

1 % of max. 1 % of max.

General pressure transducer

(not a part of another instrument) p 5 s 1 Hz 5 % of pt. or5 % of max.

2 % of pt. or

0.5 % of max. 1 % of max

Atmospheric pressure meter patmos 50 s 0.1 Hz 250 Pa 200 Pa 100 Pa

General temperature sensor

(not a part of another instrument) T 5 s 1 Hz 1 % of pt. K or5 K

0.5 % of pt. K or

2 K

0.5 % of max

0.5 K

General dewpoint sensor Tdew 50 s 0.1 Hz 3 K 1 K 1 K

Exhaust flow meter n 1 s 1 Hz means 5 % of pt. or

3 % of max. 2 % of pt. 2 % of max.

Dilution air, inlet air, exhaust, and sample 

flow meters n 1 s 1 Hz means 2.5 % of pt. or1.5 % of max.

1.25 % of pt. or

0.75 % of max. 1 % of max.

Continuous gas analyzer x 5 s 1 Hz 4 % of pt. or

4 % of meas.

2 % of pt. or

2 % of meas. 1 % of max.

Gravimetric PM balance mPM — — See § 1065.790 0.5 g —

Inertial PM balance mPM — —

4 % of pt. or

4 % of meas.

2 % of pt. or

2 % of meas. 1 % of max

1Accuracy, repeatability, and noise are all determined with the same collected data, as described in § 1065.305, and based on absolute values. “pt.” refers to the overall 

flow-weighted mean value expected at the standard; “max.” refers to the peak value expected at the standard over any test interval, not the maximum of the instrument’s 

range; “meas” refers to the actual flow-weighted mean measured over any test interval.
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* * * * *

326. Section 1065.920 is amended by revising paragraphs (a), (b) introductory text, 

and (b)(7) introductory text to read as follows:

§ 1065.920 PEMS Calibrations and verifications.

(a) Subsystem calibrations and verifications. Use all the applicable calibrations and 

verifications in subpart D of this part, including the linearity verifications in § 1065.307, 

to calibrate and verify PEMS. Note that a PEMS does not have to meet the systemresponse and updating-recording verifications of § 1065.308 and § 1065.309 if it meets 

the overall verification described in paragraph (b) of this section or if it measures PM 

using any method other than that described in § 1065.170(c)(1). This section does not 

apply to ECM signals. Note that because the regulations of this part require you to use 

good engineering judgment, it may be necessary to perform additional verifications and 

analysis. It may also be necessary to limit the range of conditions under which the PEMS 

can be used or to include specific additional maintenance to ensure that it functions 

properly under the test conditions. As provided in 40 CFR 1068.5, we will deem your 

system to not meet the requirements of this section if we determine that you did not use 

good engineering judgment to verify the measurement equipment. We may also deem 

your system to meet these requirements only under certain test conditions. If we ask for 

it, you must send us a summary of your verifications. We may also ask you to provide 

additional information or analysis to support your conclusions.

(b) Overall verification. This paragraph (b) specifies methods and criteria for verifying 

the overall performance of systems not fully compliant with requirements that apply for 

laboratory testing. Maintain records to show that the particular make, model, and 

configuration of your PEMS meets this verification. You may rely on data and other 

information from the PEMS manufacturer. However, we recommend that you generate 

your own records to show that your specific PEMS meets this verification. If you 

upgrade or change the configuration of your PEMS, your record must show that your new 

configuration meets this verification. The verification required by this section consists of 

operating an engine over a duty cycle in the laboratory and statistically comparing data 

generated and recorded by the PEMS with data simultaneously generated and recorded by

laboratory equipment as follows:

* * * * *

(7) The PEMS passes the verification of this paragraph (b) if any one of the following are 

true for each constituent:

* * * * *

Subpart K—[Amended]

327. Section 1065.1001 is amended as follows:

a. By removing the definition for “C1 equivalent (or basis)”.

b. By adding a definition for “C1-equivalent (or basis)”.

c. By removing the definition for “Engine”.
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d. By revising the definitions for “HEPA filter”, “Hydrocarbon (HC)”, “Oxygenated 

fuels”, and “Precision”.

e. By adding a definition for “Purified air”.

§ 1065.1001 Definitions.

* * * * *

C1-equivalent (or basis) means a convention of expressing HC concentrations 

based on the total number of carbon atoms present, such that the C1 equivalent of a molar 

HC concentration equals the molar concentration multiplied by the mean number of 

carbon atoms in each HC molecule. For example, the C1 equivalent of 10 mol/mol of 

propane (C3H8) is 30 mol/mol. C1 equivalent molar values may be denoted as “ppmC” 

in the standard-setting part. Molar mass may also be expressed on a C1 basis. Note that 

calculating HC masses from molar concentrations and molar masses is only valid where 

they are each expressed on the same carbon basis.

* * * * *

HEPA filter means high-efficiency particulate air filters that are rated to achieve a 

minimum initial particle-removal efficiency of 99.97 % using ASTM F1471 

(incorporated by reference in § 1065.1010).

* * * * *

Hydrocarbon (HC) means THC, THCE, NMHC, NMOG, or NMHCE, as 

applicable. Hydrocarbon generally means the hydrocarbon group on which the emission 

standards are based for each type of fuel and engine.

* * * * *

Oxygenated fuels means fuels composed of at least 25 % oxygen-containing 

compounds, such as ethanol or methanol. Testing engines that use oxygenated fuels 

generally requires the use of the sampling methods in subpart I of this part. However, 

you should read the standard-setting part and subpart I of this part to determine 

appropriate sampling methods.

* * * * *

Precision means two times the standard deviation of a set of measured values of a 

single zero or reference quantity. See also the related definitions of noise and 

repeatability in this section.

* * * * *

Purified air means air meeting the specifications for purified air in § 1065.750. 

Purified air may be produced by purifying ambient air. The purification may occur at the 

test site or at another location (such as at a gas supplier’s facility). Alternatively, purified 

air may be synthetically generated, using good engineering judgment, from purified 

oxygen and nitrogen. The addition of other elements normally present in purified 

ambient air (such as Ar) is not required.

* * * * *

328. Section 1065.1005 is revised to read as follows:

§ 1065.1005 Symbols, abbreviations, acronyms, and units of measure.

The procedures in this part generally follow the International System of Units (SI), as 

detailed in NIST Special Publication 811, which we incorporate by reference in § 
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1065.1010. See § 1065.20 for specific provisions related to these conventions. This 

section summarizes the way we use symbols, units of measure, and other abbreviations.

(a) Symbols for quantities. This part uses the following symbols and units of measure for 

various quantities:

Symbol Quantity Unit Unit symbol Units in terms of SI 

base units

 atomic hydrogen-to-carbon ratio mole per mole mol/mol 1

A area square meter m

2 m2

a0intercept of least squares regression

a1 slope of least squares regression

ag acceleration of Earth’s gravity meter per square second m/s2 m/s2

 ratio of diameters meter per meter m/m 1

 atomic oxygen-to-carbon ratio mole per mole mol/mol 1

C# number of carbon atoms in a molecule

Cd discharge coefficient

Cfflow coefficient

δ atomic nitrogen-to-carbon ratio mole per mole mol/mol 1

d Diameter meter m m

DR dilution ratio mole per mole mol/mol 1



error between a quantity and its 

reference

e

brake-specific emission or fuel 

consumption gram per kilowatt hour g/(kW∙hr) g∙3.6-1

∙106∙m-2∙kg∙s2

F F-test statistic

f frequency hertz Hz s

-1

fn angular speed (shaft) revolutions per minute r/min 2∙π∙60-1∙m·m-1·s-1

 ratio of specific heats

(joule per kilogram 

kelvin) per (joule per 

kilogram kelvin) 

(J/(kg∙K))/(J/(kg∙K)) 1

 atomic sulfur-to-carbon ratio mole per mole mol/mol 1

K correction factor 1

Kv calibration coefficient m

4

∙s∙K0.5/kg m

4

∙s∙K0.5∙kg-1

l length meter m m

 viscosity, dynamic pascal second Pa∙s m

-1

∙kg∙s-1

M molar mass1gram per mole g/mol 10-3∙kg∙mol-1

m mass kilogram kg kg

m mass rate kilogram per second kg/s kg∙s-1

 viscosity, kinematic meter squared per 

second

m

2

/s m

2

∙s-1

N total number in series

n amount of substance mole mol mol

n amount of substance rate mole per second mol/s mol∙s-1

P power kilowatt kW 103∙m2∙kg∙s-3

PF penetration fraction

p pressure pascal Pa m

-1

∙kg∙s-2

 mass density kilogram per cubic 

meter kg/m3

kg∙m-3

p differential static pressure pascal Pa m

-1

∙kg∙s-2

r ratio of pressures pascal per pascal Pa/Pa 1

r

2

coefficient of determination

Ra average surface roughness micrometer m 10-6 m

Re# Reynolds number

RF response factor

RH relative humidity
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 903 of 1039

 non-biased standard deviation

S Sutherland constant kelvin K K

SEE standard estimate of error

T absolute temperature kelvin K K

T Celsius temperature degree Celsius °C K-273.15

T torque (moment of force) newton meter N∙m m

2

∙kg∙s-2

 plane angle degrees ° rad

t time second s s

t time interval, period, 1/frequency second s s

V volume cubic meter m

3 m3

V

 volume rate cubic meter per second m

3

/s m

3

∙s-1

W work kilowatt hour kW∙hr 3.6∙10-6∙m2∙kg∙s-2

wc carbon mass fraction gram per gram g/g 1

x amount of substance mole fraction2 mole per mole mol/mol 1

x flow-weighted mean concentration mole per mole mol/mol 1

y generic variable

Z compressibility factor

1

See paragraph (f)(2) of this section for the values to use for molar masses. Note that in the cases of NOx and HC, the 

regulations specify effective molar masses based on assumed speciation rather than actual speciation. 

2 Note that mole fractions for THC, THCE, NMHC, NMHCE, and NOTHC are expressed on a C1 equivalent basis. 

(b) Symbols for chemical species. This part uses the following symbols for chemical 

species and exhaust constituents:

Symbol Species

Ar argon

C carbon

CH2O formaldehyde

CH3OH methanol

CH4 methane

C2H4O acetaldehyde

C2H5OH ethanol

C2H6 ethane

C3H7OH propanol

C3H8 propane

C4H10 butane

C5H12 pentane

CO carbon monoxide

CO2 carbon dioxide

H atomic hydrogen

H2 molecular hydrogen

H2O water

H2SO4 sulfuric acid

HC hydrocarbon

He helium

85Kr krypton 85

N2 molecular nitrogen

NH3 ammonia

NMHC nonmethane hydrocarbon

NMHCE nonmethane hydrocarbon equivalent

NO nitric oxide

NO2 nitrogen dioxide

NOx oxides of nitrogen

N2O nitrous oxide

NMOG nonmethane organic gases
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 904 of 1039

NONMHC non-oxygenated nonmethane hydrocarbon

NOTHC non-oxygenated total hydrocarbon

O2 molecular oxygen

OHC oxygenated hydrocarbon

210Po polonium 210

PM particulate matter

S sulfur

SVOC semi-volatile organic compound

THC total hydrocarbon

THCE total hydrocarbon equivalent

ZrO2 zirconium dioxide

(c) Prefixes. This part uses the following prefixes to define a quantity:

Symbol Quantity Value

 micro 10-6

m milli 10-3

c centi 10-2

k kilo 103

M mega 106

(d) Superscripts. This part uses the following superscripts to define a quantity:

Superscript Quantity

overbar (such as y ) arithmetic mean

overdot (such as y ) quantity per unit time

(e) Subscripts. This part uses the following subscripts to define a quantity:

Subscript Quantity

abs absolute quantity

act actual condition

air air, dry

amb ambient

atmos atmospheric

bkgnd background

cal calibration quantity

CFV critical flow venturi

comb combined

composite composite value

cor corrected quantity

dil dilution air

dew dewpoint

dexh diluted exhaust

dry dry condition

dutycycle duty cycle

exh raw exhaust

exp expected quantity

fn feedback speed

frict friction

fuel fuel consumption

hi,idle condition at high-idle

i an individual of a series

idle condition at idle

in quantity in

init initial quantity, typically before an emission test

int intake air
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 905 of 1039

j an individual of a series

mapped conditions over which an engine can operate

max

the maximum (i.e., peak) value expected at the standard over a 

test interval; not the maximum of an instrument range

meas measured quantity

media PM sample media

mix mixture of diluted exhaust and air

norm normalized

out quantity out

P power

part partial quantity

PDP positive-displacement pump

post after the test interval

pre before the test interval

prod stoichiometric product

record record rate

ref reference quantity

rev revolution

sat saturated condition

s slip

span span quantity

SSV subsonic venturi

std standard condition

stroke engine strokes per power stroke

T torque

test test quantity

test,alt alternate test quantity

uncor uncorrected quantity

vac vacuum side of the sampling system

weight calibration weight

zero zero quantity

(f) Constants. (1) This part uses the following constants for the composition of dry air:

Symbol Quantity mol/mol 

xArair amount of argon in dry air 0.00934

xCO2air amount of carbon dioxide in dry air 0.000375

xN2air amount of nitrogen in dry air 0.78084

xO2air amount of oxygen in dry air 0.209445

(2) This part uses the following molar masses or effective molar masses of chemical 

species:

Symbol Quantity g/mol

(10-3·kg·mol-1)

Mair molar mass of dry air128.96559

MAr molar mass of argon 39.948

MC molar mass of carbon 12.0107

MCH3OH molar mass of methanol 32.04186

MC2H5OH molar mass of ethanol 46.06844

MC2H4O molar mass of acetaldehyde 44.05256

MC3H8 molar mass of propane 44.09562

MC3H7OH molar mass of propanol 60.09502

MCO molar mass of carbon monoxide 28.0101

MCH4 molar mass of methane 16.0425

MCO2 molar mass of carbon dioxide 44.0095
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 906 of 1039

MH molar mass of atomic hydrogen 1.00794

MH2 molar mass of molecular hydrogen 2.01588

MH2O molar mass of water 18.01528

MCH2O molar mass of formaldehyde 30.02598

MHe molar mass of helium 4.002602

MN molar mass of atomic nitrogen 14.0067

MN2 molar mass of molecular nitrogen 28.0134

MNH3 molar mass of ammonia 17.03052

MNMHC effective C1 molar mass of nonmethane hydrocarbon213.875389

MNMHCE

effective C1 molar mass of nonmethane hydrocarbon 

equivalent2 13.875389

MNOx effective molar mass of oxides of nitrogen346.0055

MN2O molar mass of nitrous oxide 44.0128

MO molar mass of atomic oxygen 15.9994

MO2 molar mass of molecular oxygen 31.9988

MS molar mass of sulfur 32.065

MTHC effective C1 molar mass of total hydrocarbon213.875389

MTHCE effective C1 molar mass of total hydrocarbon equivalent213.875389

1

See paragraph (f)(1) of this section for the composition of dry air.

2The effective molar masses of THC, THCE, NMHC, and NMHCE are defined on a C1 basis and 

are based on an atomic hydrogen-to-carbon ratio, , of 1.85 (with β, γ, and δ equal to zero).

3The effective molar mass of NOx

is defined by the molar mass of nitrogen dioxide, NO2.

(3) This part uses the following molar gas constant for ideal gases:

Symbol Quantity J/(mol∙K)

(m2∙kg∙s-2∙mol-1∙K-1)

R molar gas constant 8.314472

(4) This part uses the following ratios of specific heats for dilution air and diluted 

exhaust:

Symbol Quantity [J/(kg∙K)]/[J/(kg∙K)] 

air ratio of specific heats for intake air 

or dilution air

1.399

dil ratio of specific heats for diluted 

exhaust

1.399

exh ratio of specific heats for raw 

exhaust

1.385

(g) Other acronyms and abbreviations. This part uses the following additional 

abbreviations and acronyms: 

ABS acrylonitrile-butadiene-styrene

ASTM American Society for Testing and Materials

BMD bag mini-diluter

BSFC brake-specific fuel consumption

CARB California Air Resources Board

CFR Code of Federal Regulations

CFV critical-flow venturi

CI compression-ignition

CITT Curb Idle Transmission Torque

CLD chemiluminescent detector

CVS constant-volume sampler

DF deterioration factor

ECM electronic control module

EFC electronic flow control
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 907 of 1039

e.g. for example

EGR exhaust gas recirculation

EPA Environmental Protection Agency

FEL Family Emission Limit

FID flame-ionization detector

FTIR Fourier transform infrared

GC gas chromatograph

GC-ECD gas chromatograph with an electron-capture detector

GC-FID gas chromatograph with a flame ionization detector

HEPA high-efficiency particulate air

IBP initial boiling point

IBR incorporated by reference

i.e. in other words

ISO International Organization for Standardization

LPG liquefied petroleum gas

MPD magnetopneumatic detection

NDIR nondispersive infrared

NDUV nondispersive ultraviolet

NIST National Institute for Standards and Technology

NMC nonmethane cutter

PDP positive-displacement pump

PEMS portable emission measurement system

PFD partial-flow dilution

PLOT porous layer open tubular

PMD paramagnetic detection

PMP Polymethylpentene

pt. a single point at the mean value expected at the standard.

psi pounds per square inch

PTFE polytetrafluoroethylene (commonly known as TeflonTM)

RE rounding error

RESS rechargeable energy storage system

RFPF response factor penetration fraction

RMC ramped-modal cycle

rms root-mean square

RTD resistive temperature detector

SAW surface acoustic wave

SEE standard estimate of error

SSV subsonic venturi

SI spark-ignition

THC-FID total hydrocarbon flame ionization detector

TINV inverse student t-test function in Microsoft Excel

UCL upper confidence limit

UFM ultrasonic flow meter

U.S.C. United States Code

329. Section 1065.1010 is revised to read as follows:

§ 1065.1010 Incorporation by reference.

(a) Certain material is incorporated by reference into this part with the approval of the 

Director of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. To enforce 

any edition other than that specified in this section, a document must be published in the 

Federal Register and the material must be available to the public. All approved 

materials are available for inspection at the Air and Radiation Docket and Information 

Center (Air Docket) in the EPA Docket Center (EPA/ DC) at Rm. 3334, EPA West 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 908 of 1039

Bldg., 1301 Constitution Ave. NW., Washington, DC. The EPA/DC Public Reading 

Room hours of operation are 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding 

legal holidays. The telephone number of the EPA/DC Public Reading Room is (202) 

566–1744, and the telephone number for the Air Docket is (202) 566–1742. These 

approved materials are also available for inspection at the National Archives and Records 

Administration (NARA). For information on the availability of this material at NARA, 

call (202) 741–6030 or go to http:// www.archives.gov/federal_register/ 

code_of_federal_regulations/ ibr_locations.html. In addition, these materials are 

available from the sources listed below.

(b) ASTM material. The following standards are available from ASTM International, 100 

Barr Harbor Dr., P.O. Box C700, West Conshohocken, PA 19428–2959, (877) 909–

ASTM, or http://www.astm.org:

(1) ASTM D86-12, Standard Test Method for Distillation of Petroleum Products at 

Atmospheric Pressure, approved December 1, 2012, IBR approved for §§ 1065.703(b) 

and 1065.710(b) and (c).

(2) ASTM D93-13, Standard Test Methods for Flash Point by Pensky- Martens Closed 

Cup Tester, approved July 15, 2013, IBR approved for § 1065.703(b).

(3) ASTM D130-12, Standard Test Method for Corrosiveness to Copper from Petroleum 

Products by Copper Strip Test, approved November 1, 2012, IBR approved for § 

1065.710(b).

(4) ASTM D381-12, Standard Test Method for Gum Content in Fuels by Jet Evaporation, 

approved April 15, 2012, IBR approved for § 1065.710(b).

(5) ASTM D445-12, Standard Test Method for Kinematic Viscosity of Transparent and 

Opaque Liquids (and Calculation of Dynamic Viscosity), approved April 15, 2012, IBR 

approved for § 1065.703(b).

(6) ASTM D525-12a, Standard Test Method for Oxidation Stability of Gasoline 

(Induction Period Method), approved September 1, 2012, IBR approved for § 

1065.710(b).

(7) ASTM D613-13, Standard Test Method for Cetane Number of Diesel Fuel Oil, 

approved December 1, 2013, IBR approved for § 1065.703(b).

(8) ASTM D910-13a, Standard Specification for Aviation Gasolines, approved December 

1, 2013, IBR approved for § 1065.701(f).

(9) ASTM D975-13a, Standard Specification for Diesel Fuel Oils, approved December 1, 

2013, IBR approved for § 1065.701(f).

(10) ASTM D1267-12, Standard Test Method for Gage Vapor Pressure of Liquefied 

Petroleum (LP) Gases (LP-Gas Method), approved November 1, 2012, IBR approved for 

§ 1065.720(a).

(11) ASTM D1319-13, Standard Test Method for Hydrocarbon Types in Liquid 

Petroleum Products by Fluorescent Indicator Adsorption, approved May 1, 2013, IBR 

approved for § 1065.710(c).

(12) ASTM D1655-13a, Standard Specification for Aviation Turbine Fuels, approved 

December 1, 2013, IBR approved for § 1065.701(f).

(13) ASTM D1837-11, Standard Test Method for Volatility of Liquefied Petroleum (LP) 

Gases, approved October 1, 2011, IBR approved for § 1065.720(a).
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 909 of 1039

(14) ASTM D1838-12a, Standard Test Method for Copper Strip Corrosion by Liquefied 

Petroleum (LP) Gases, approved December 1, 2012, IBR approved for § 1065.720(a).

(15) ASTM D1945-03 (Reapproved 2010), Standard Test Method for Analysis of Natural 

Gas by Gas Chromatography, approved January 1, 2010, IBR approved for § 

1065.715(a).

(16) ASTM D2158-11, Standard Test Method for Residues in Liquefied Petroleum (LP) 

Gases, approved January 1, 2011, IBR approved for § 1065.720(a).

(17) ASTM D2163-07, Standard Test Method for Determination of Hydrocarbons in 

Liquefied Petroleum (LP) Gases and Propane/Propene Mixtures by Gas Chromatography, 

approved December 1, 2007, IBR approved for §1065.720(a).

(18) ASTM D2598-12, Standard Practice for Calculation of Certain Physical Properties 

of Liquefied Petroleum (LP) Gases from Compositional Analysis, approved November 1, 

2012, IBR approved for § 1065.720(a).

(19) ASTM D2622-10, Standard Test Method for Sulfur in Petroleum Products by

Wavelength Dispersive X-ray Fluorescence Spectrometry, approved February 15, 2010, 

IBR approved for §§ 1065.703(b) and 1065.710(b) and (c).

(20) ASTM D2699-13b, Standard Test Method for Research Octane Number of SparkIgnition Engine Fuel, approved October 1, 2013, IBR approved for § 1065.710(b).

(21) ASTM D2700-13b, Standard Test Method for Motor Octane Number of SparkIgnition Engine Fuel, approved October 1, 2013, IBR approved for § 1065.710(b).

(22) ASTM D2713-13, Standard Test Method for Dryness of Propane (Valve Freeze 

Method), approved October 1, 2013, IBR approved for § 1065.720(a).

(23) ASTM D2784-11, Standard Test Method for Sulfur in Liquefied Petroleum Gases 

(Oxy-Hydrogen Burner or Lamp), approved January 1, 2011, IBR approved for § 

1065.720(a).

(24) ASTM D2880-13b, Standard Specification for Gas Turbine Fuel Oils, approved 

November 15, 2013, IBR approved for § 1065.701(f).

(25) ASTM D2986-95a (Reapproved 1999), Standard Practice for Evaluation of Air 

Assay Media by the Monodisperse DOP (Dioctyl Phthalate) Smoke Test, approved 

September 10, 1995, IBR approved for § 1065.170(c). (Note: This standard was 

withdrawn by ASTM.)

(26) ASTM D3231-13, Standard Test Method for Phosphorus in Gasoline, approved June 

15, 2013, IBR approved for § 1065.710(b) and (c).

(27) ASTM D3237-12, Standard Test Method for Lead in Gasoline By Atomic 

Absorption Spectroscopy, approved June 1, 2012, IBR approved for § 1065.710(b) and 

(c).

(28) ASTM D4052-11, Standard Test Method for Density, Relative Density, and API 

Gravity of Liquids by Digital Density Meter, approved October 15, 2011, IBR approved 

for § 1065.703(b).

(29) ASTM D4629-12, Standard Test Method for Trace Nitrogen in Liquid Petroleum 

Hydrocarbons by Syringe/Inlet Oxidative Combustion and Chemiluminescence 

Detection, approved April 15, 2012, IBR approved for § 1065.655(d).

(30) ASTM D4814-13b, Standard Specification for Automotive Spark-Ignition Engine 

Fuel, approved December 1, 2013, IBR approved for § 1065.701(f).
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 910 of 1039

(31) ASTM D4815-13, Standard Test Method for Determination of MTBE, ETBE, 

TAME, DIPE, tertiary-Amyl Alcohol and C1 to C4 Alcohols in Gasoline by Gas 

Chromatography, approved October 1, 2013, IBR approved for § 1065.710(b).

(32) ASTM D5186-03 (Reapproved 2009), Standard Test Method for Determination of 

the Aromatic Content and Polynuclear Aromatic Content of Diesel Fuels and Aviation 

Turbine Fuels By Supercritical Fluid Chromatography, approved April 15, 2009, IBR 

approved for § 1065.703(b).

(33) ASTM D5191-13, Standard Test Method for Vapor Pressure of Petroleum Products 

(Mini Method), approved December 1, 2013, IBR approved for § 1065.710(b) and (c).

(34) ASTM D5291-10, Standard Test Method for Instrumental Determination of Carbon, 

Hydrogen, and Nitrogen in Petroleum Products and Lubricants, approved May 1, 2010, 

IBR approved for § 1065.655(d).

(35) ASTM D5453-12, Standard Test Method for Determination of Total Sulfur in Light 

Hydrocarbons, Spark Ignition Engine Fuel, Diesel Engine Fuel, and Engine Oil by

Ultraviolet Fluorescence, approved November 1, 2012, IBR approved for § 1065.710(b).

(36) ASTM D5599-00 (Reapproved 2010), Standard Test Method for Determination of 

Oxygenates in Gasoline by Gas Chromatography and Oxygen Selective Flame Ionization 

Detection, approved October 1, 2010, IBR approved for §§ 1065.655(d) and 1065.710(b).

(37) ASTM D5762-12 Standard Test Method for Nitrogen in Petroleum and Petroleum 

Products by Boat-Inlet Chemiluminescence, approved April 15, 2012, IBR approved for 

§ 1065.655(d).

(38) ASTM D5769-10, Standard Test Method for Determination of Benzene, Toluene, 

and Total Aromatics in Finished Gasolines by Gas Chromatography/Mass Spectrometry, 

approved May 1, 2010, IBR approved for § 1065.710(b).

(39) ASTM D5797-13, Standard Specification for Fuel Methanol (M70- M85) for 

Automotive Spark-Ignition Engines, approved June 15, 2013, IBR approved for § 

1065.701(f).

(40) ASTM D5798-13a, Standard Specification for Ethanol Fuel Blends for Flexible Fuel 

Automotive Spark-Ignition Engines, approved June 15, 2013, IBR approved for § 

1065.701(f).

(41) ASTM D6550-10, Standard Test Method for Determination of Olefin Content of 

Gasolines by Supercritical-Fluid Chromatography, approved October 1, 2010, IBR 

approved for § 1065.710(b).

(42) ASTM D6615-11a, Standard Specification for Jet B Wide-Cut Aviation Turbine 

Fuel, approved October 1, 2011, IBR approved for § 1065.701(f).

(43) ASTM D6751-12, Standard Specification for Biodiesel Fuel Blend Stock (B100) for 

Middle Distillate Fuels, approved August 1, 2012, IBR approved for § 1065.701(f).

(44) ASTM D6985-04a, Standard Specification for Middle Distillate Fuel Oil—Military

Marine Applications, approved November 1, 2004, IBR approved for § 1065.701(f). 

(Note: This standard was withdrawn by ASTM.)

(45) ASTM D7039-13, Standard Test Method for Sulfur in Gasoline, Diesel Fuel, Jet 

Fuel, Kerosine, Biodiesel, Biodiesel Blends, and Gasoline-Ethanol Blends by

Monochromatic Wavelength Dispersive X-ray Fluorescence Spectrometry, approved 

September 15, 2013, IBR approved for § 1065.710(b).
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 911 of 1039

(46) ASTM F1471-09, Standard Test Method for Air Cleaning Performance of a HighEfficiency Particulate Air Filter System, approved March 1, 2009, IBR approved for § 

1065.1001.

(c) California Air Resources Board material. The following documents are available 

from the California Air Resources Board, Haagen-Smit Laboratory, 9528 Telstar Ave., El 

Monte, CA 91731–2908, (800) 242–4450, or http://www.arb.ca.gov:

(1) California Non-Methane Organic Gas Test Procedures, Amended July 30, 2002, 

Mobile Source Division, California Air Resources Board, IBR approved for § 

1065.805(f).

(2) [Reserved]

(d) Institute of Petroleum material. The following documents are available from the 

Energy Institute, 61 New Cavendish St., London, W1G 7AR, UK, or by calling +44–

(0)20–7467–7100, or at http://www.energyinst.org:

(1) IP 470, 2005, Determination of aluminum, silicon, vanadium, nickel, iron, calcium, 

zinc, and sodium in residual fuels by atomic absorption spectrometry, IBR approved for § 

1065.705(b).

(2) IP 500, 2003, Determination of the phosphorus content of residual fuels by ultraviolet spectrometry, IBR approved for § 1065.705(b).

(3) IP 501, 2005, Determination of aluminum, silicon, vanadium, nickel, iron, sodium, 

calcium, zinc and phosphorus in residual fuel oil by ashing, fusion and inductively

coupled plasma emission spectrometry, IBR approved for § 1065.705(b).

(e) ISO material. The following standards are available from the International 

Organization for Standardization, 1, ch. de la Voie-Creuse, CP 56, CH–1211 Geneva 20,

Switzerland, 41–22–749–01–11, or http://www.iso.org:

(1) ISO 2719:2002, Determination of flash point—Pensky-Martens closed cup method, 

IBR approved for § 1065.705(c).

(2) ISO 3016:1994, Petroleum products—Determination of pour point, IBR approved for 

§ 1065.705(c).

(3) ISO 3104:1994/Cor 1:1997, Petroleum products—Transparent and opaque liquids—

Determination of kinematic viscosity and calculation of dynamic viscosity, IBR approved 

for § 1065.705(c).

(4) ISO 3675:1998, Crude petroleum and liquid petroleum products— Laboratory

determination of density— Hydrometer method, IBR approved for § 1065.705(c).

(5) ISO 3733:1999, Petroleum products and bituminous materials— Determination of 

water—Distillation method, IBR approved for § 1065.705(c).

(6) ISO 6245:2001, Petroleum products—Determination of ash, IBR approved for § 

1065.705(c).

(7) ISO 8217:2012, Petroleum products—Fuels (class F)—Specifications of marine fuels, 

Fifth edition, revised August 15, 2012, IBR approved for § 1065.705(b) and (c).

(8) ISO 8754:2003, Petroleum products—Determination of sulfur content—Energydispersive X-ray Fluorescence spectrometry, IBR approved for § 1065.705(c).

(9) ISO 10307–2(E):2009, Petroleum products—Total sediment in residual fuel oils—

Part 2: Determination using standard procedures for ageing, Second Ed., February 1, 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 912 of 1039

2009, as modified by ISO 10307-2:2009/Cor.1:2010(E), Technical Corrigendum 1, 

published May 15, 2010, IBR approved for § 1065.705(c).

(10) ISO 10370:1993/Cor 1:1996, Petroleum products—Determination of carbon 

residue—Micro method, IBR approved for § 1065.705(c).

(11) ISO 10478:1994, Petroleum products—Determination of aluminium and silicon in 

fuel oils—Inductively coupled plasma emission and atomic absorption spectroscopy

methods, IBR approved for § 1065.705(c).

(12) ISO 12185:1996/Cor 1:2001, Crude petroleum and petroleum products—

Determination of density—Oscillating U-tube method, IBR approved for § 1065.705(c).

(13) ISO 14596:2007, Petroleum products—Determination of sulfur content—

Wavelength-dispersive X-ray fluorescence spectrometry, IBR approved for § 

1065.705(c).

(14) ISO 14597:1997, Petroleum products—Determination of vanadium and nickel 

content—Wavelength dispersive X-ray fluorescence spectrometry, IBR approved for § 

1065.705(c).

(15) ISO 14644–1:1999, Cleanrooms and associated controlled environments, IBR 

approved for § 1065.190(b).

(f) NIST material. The following documents are available from National Institute of 

Standards and Technology, 100 Bureau Drive, Stop 1070, Gaithersburg, MD 20899-

1070, (301) 975-6478, or www.nist.gov:

(1) NIST Special Publication 811, 2008 Edition, Guide for the Use of the International 

System of Units (SI), March 2008, IBR approved for §§ 1065.20(a) and 1065.1005.

(2) NIST Technical Note 1297, 1994 Edition, Guidelines for Evaluating and Expressing 

the Uncertainty of NIST Measurement Results, Barry N. Taylor and Chris E. Kuyatt, IBR 

approved for § 1065.1001.

(g) SAE International material. The following standards are available from SAE 

International, 400 Commonwealth Dr., Warrendale, PA 15096–0001, (724) 776–4841, or 

http://www.sae.org:

(1) SAE 770141, 1977, Optimization of Flame Ionization Detector for Determination of 

Hydrocarbon in Diluted Automotive Exhausts, Glenn D. Reschke, IBR approved for § 

1065.360(c).

(2) SAE J1151, Methane Measurement Using Gas Chromatography, stabilized September 

2011, IBR approved for §§ 1065.267(b) and 1065.750(a).

330. A new subpart L consisting of § 1065.1101 through § 1065.1111 is added to part 

1065 to read as follows:

Subpart L—METHODS FOR UNREGULATED AND SPECIAL POLLUTANTS

Sec.

1065.1101 Applicability.

SEMI-VOLATILE ORGANIC COMPOUNDS

1065.1103 General provisions for SVOC measurement.

1065.1105 Sampling system design.

1065.1107 Sample media and sample system preparation; sampler assembly.
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 913 of 1039

1065.1109 Post-test sampler disassembly and sample extraction.

1065.1111 Sample analysis.

Subpart L—METHODS FOR UNREGULATED AND SPECIAL POLLUTANTS

§ 1065.1101 Applicability.

This subpart specifies procedures that may be used to measure emission constituents that 

are not measured (or not separately measured) by the test procedures in the other subparts 

of this part. These procedures are included to facilitate consistent measurement of 

unregulated pollutants for purposes other than compliance with emission standards. 

Unless otherwise specified in the standard-setting part, use of these procedures is optional 

and does not replace any requirements in the rest of this part. 

SEMI-VOLATILE ORGANIC COMPOUNDS

§ 1065.1103 General provisions for SVOC measurement.

The provisions of §§ 1065.1103 through 1065.1111 specify procedures for measuring 

semi-volatile organic compounds (SVOC) along with PM. These sections specify how to 

collect a sample of the SVOCs during exhaust emission testing, as well as how to use wet 

chemistry techniques to extract SVOCs from the sample media for analysis. Note that 

the precise method you use will depend on the category of SVOCs being measured. For 

example, the method used to measure polynuclear aromatic hydrocarbons (PAHs) will 

differ slightly from the method used to measure dioxins. Follow standard analytic 

chemistry methods for any aspects of the analysis that are not specified.

(a) Laboratory cleanliness is especially important throughout SVOC testing. Thoroughly 

clean all sampling system components and glassware before testing to avoid sample 

contamination. For the purposes of this subpart, the sampling system is defined as 

sample pathway from the sample probe inlet to the downstream most point where the 

sample is captured (in this case the condensate trap).

(b) We recommend that media blanks be analyzed for each batch of sample media 

(sorbent, filters, etc.) prepared for testing. Blank sorbent modules (i.e., field blanks) 

should be stored in a sealed environment and should periodically accompany the test 

sampling system throughout the course of a test, including sampling system and sorbent 

module disassembly, sample packaging, and storage. Use good engineering judgment to 

determine the frequency with which you should generate field blanks. The field blank 

sample should be close to the sampler during testing.

(c) We recommend the use of isotope dilution techniques, including the use of 

isotopically labeled surrogate, internal, alternate, and injection standards.

(d) If your target analytes degrade when exposed to ultraviolet radiation, such as 

nitropolynuclear aromatic hydrocarbons (nPAHs), perform these procedures in the dark 

or with ultraviolet filters installed over the lights.

(e) The following definitions and abbreviations apply for SVOC measurements:
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(1) Soxhlet extraction means the extraction method invented by Franz von Soxhlet, in 

which the sample is placed in a thimble and rinsed repeatedly with a recycle of the 

extraction solvent.

(2) XAD-2 means a hydrophobic crosslinked polystyrene copolymer resin adsorbent 

known commercially as Amberlite® XAD®-2, or an equivalent adsorbent like XAD-4.

(3) Semi-volatile organic compound (SVOC) means an organic compound that is 

sufficiently volatile to exist in vapor form in engine exhaust, but that readily condenses to 

liquid or solid form under atmospheric conditions. Most SVOCs have at least 14 carbon 

atoms per molecule or they have a boiling point between (240 and 400) °C. SVOCs 

include dioxin, quinone, and nitro-PAH compounds. They may be a natural byproduct of 

combustion or they may be created post-combustion. Note that SVOCs may be included 

in measured values of hydrocarbons and/or PM using the procedures specified in this 

part.

(4) Kuderna-Danish concentrator means laboratory glassware known by this name that 

consists of an air-cooled condenser on top of an extraction bulb.

(5) Dean-Stark trap means laboratory glassware known by this name that uses a reflux 

condenser to collect water from samples extracted under reflux.

(6) PUF means polyurethane foam.

(7) Isotopically labeled means relating to a compound in which either all the hydrogen 

atoms are replaced with the atomic isotope hydrogen-2 (deuterium) or one of the carbon 

atoms at a defined position in the molecule is replaced with the atomic isotope carbon-13.

§ 1065.1105 Sampling system design.

(a) General. We recommend that you design your SVOC batch sampler to extract sample 

from undiluted emissions to maximize the sampled SVOC quantity. To the extent 

practical, adjust sampling times based on the emission rate of target analytes from the 

engine to obtain analyte concentrations above the detection limit. In some instances you 

may need to run repeat test cycles without replacing the sample media or disassembling 

the batch sampler.

(b) Sample probe, transfer lines, and sample media holder design and construction. The 

sampling system should consist of a sample probe, transfer line, PM filter holder, cooling 

coil, sorbent module, and condensate trap. Construct sample probes, transfer lines, and 

sample media holders that have inside surfaces of nickel, titanium or another nonreactive 

material capable of withstanding raw exhaust gas temperatures. Seal all joints in the hot 

zone of the system with gaskets made of nonreactive material similar to that of the 

sampling system components. You may use teflon gaskets in the cold zone. We 

recommend locating all components as close to probes as practical to shorten sampling 

system length and minimize the surface exposed to engine exhaust.

(c) Sample system configuration. This paragraph (c) specifies the components necessary

to collect SVOC samples, along with our recommended design parameters. Where you 

do not follow our recommendations, use good engineering judgment to design your 

sampling system so it does not result in loss of SVOC during sampling. The sampling 

system should contain the following components in series in the order listed:

(1) Use a sample probe similar to the PM sample probe specified in subpart B of this part. 
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(2) Use a PM filter holder similar to the holder specified in subpart B of this part, 

although you will likely need to use a larger size to accommodate the high sample flow 

rates. We recommend using a 110 mm filter for testing spark ignition engines or engines 

that utilize exhaust aftertreatment for PM removal and a 293 mm filter for other engines. 

If you are not analyzing separately for SVOCs in gas and particle phases, you do not have 

to control the temperature of the filter holder. Note that this differs from normal PM 

sampling procedures, which maintain the filter at a much lower temperature to capture a 

significant fraction of exhaust SVOC on the filter. In this method, SVOCs that pass 

through the filter will be collected on the downstream sorbent module. If you are 

collecting SVOCs in gas and particle phases, control your filter face temperature 

according to § 1065.140(e)(4). 

(3) Use good engineering judgment to design a cooling coil that will drop the sample 

temperature to approximately 5 °C. Note that downstream of the cooling coil, the sample 

will be a mixture of vapor phase hydrocarbons in CO2, air, and a primarily aqueous liquid 

phase. 

(4) Use a hydrophobic sorbent in a sealed sorbent module. Note that this sorbent module 

is intended to be the final stage for collecting the SVOC sample and should be sized 

accordingly. We recommend sizing the module to hold 40 g of XAD-2 along with PUF 

plugs at either end of the module, noting that you may vary the mass of XAD used for 

testing based on the anticipated SVOC emission rate.

(5) Include a condensate trap to separate the aqueous liquid phase from the gas stream. 

We recommend using a peristaltic pump to remove water from the condensate trap over 

the course of the test to prevent build-up of the condensate. Note that for some tests it 

may be appropriate to collect this water for analysis.

(d) Sampler flow control. For testing using the recommended filter and sorbent module 

sizes, we recommend targeting an average sample flow rate of 70 liters per minute to 

maximize SVOC collection. The sampler must be designed to maintain proportional 

sampling throughout the test. Verify proportional sampling after an emission test as 

described in § 1065.545.

(e) Water bath. Design the sample system with a water bath in which the cooling coil, 

sorbent module, and condensate trap will be submerged. Use a heat exchanger or ice to 

maintain the bath temperature at (3 to 7) °C.

§ 1065.1107 Sample media and sample system preparation; sample system assembly.

This section describes the appropriate types of sample media and the cleaning procedure 

required to prepare the media and wetted sample surfaces for sampling.

(a) Sample media. The sampling system uses two types of sample media in series: the 

first to simultaneously capture the PM and associated particle phase SVOCs, and a 

second to capture SVOCs that remain in the gas phase, as follows:

(1) For capturing PM, we recommend using pure quartz filters with no binder. Select the 

filter diameter to minimize filter change intervals, accounting for the expected PM 

emission rate, sample flow rate, and number of repeat tests. Note that when repeating test 

cycles to increase sample mass, you may replace the filter without replacing the sorbent 
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or otherwise disassembling the batch sampler. In those cases, include all filters in the 

extraction.

(2) For capturing gaseous SVOCs, utilize XAD-2 resin contained between two PUF 

plugs.

(b) Sample media and sampler preparation. Prepare pre-cleaned PM filters and precleaned PUF plugs/XAD-2 as needed. Store sample media in containers protected from 

light and ambient air if you do not use them immediately after cleaning.

(1) Pre-clean the filters via Soxhlet extraction with methylene chloride for 24 hours and 

dry over dry nitrogen in a low-temperature vacuum oven.

(2) Pre-clean PUF and XAD-2 with a series of Soxhlet extractions: 8 hours with water, 22 

hours with methanol, 22 hours with methylene chloride, and 22 hours with toluene, 

followed by drying with nitrogen.

(3) Clean sampler components, including the probe, filter holder, condenser, sorbent 

module, and condensate collection vessel by rinsing three times with methylene chloride 

and then three times with toluene. Prepare pre-cleaned aluminum foil for capping the 

probe inlet of the sampler after the sampling system has been assembled.

(c) Sorbent spiking. Use good engineering judgment to verify the extent to which your 

extraction methods recover SVOCs absorbed on the sample media. We recommend 

spiking the XAD-2 resin with a surrogate standard before testing with a carbon-13 or 

hydrogen-2 isotopically labeled standard for each of the class of analytes targeted for 

analysis. Perform this spiking as follows: 

(1) Insert the lower PUF plug into the bottom of the sorbent module.

(2) Add half of one portion of XAD-2 resin to the module and spike the XAD-2 in the 

module with the standard.

(3) Wait 1 hour for the solvent from the standard(s) to evaporate, add the remaining 20 g 

of the XAD-2 resin to the module, and then insert a PUF plug in the top of the sorbent 

module.

(4) Cover the inlet and outlet of the sorbent module with pre-cleaned aluminum foil.

(d) Sampling system assembly. After preparing the sample media and the sampler, 

assemble the condensate trap, cooling coil, filter holder with filter, sample probe, and 

sorbent module, then lower the assembly into the reservoir. Cover the probe inlet with 

pre-cleaned aluminum foil.

§ 1065.1109 Post-test sampler disassembly and sample extraction.

This section describes the process for disassembling and rinsing the sampling system and 

extracting and cleaning up the sample.

(a) Sampling system disassembly. Disassemble the sampling system in a clean 

environment as follows after the test:

(1) Remove the PM filter, PUF plugs, and all the XAD-2 from the sampling system and 

place them into a Soxhlet extraction thimble. Store them at or below 37 °C until analysis.

(2) Rinse sampling system wetted surfaces upstream of the condensate trap with acetone 

followed by toluene (or a comparable solvent system), ensuring that all the solvent 

remaining in liquid phase is collected (note that a fraction of the acetone and toluene will 

likely be lost to evaporation during mixing). Rinse with solvent volumes that are 
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sufficient to cover all the surfaces exposed to the sample during testing. We recommend 

three fresh solvent rinses with acetone and two with toluene. We recommend rinse 

volumes of 60 ml per rinse for all sampling system components except the condenser 

coil, of which you should use 200 ml per rinse. Keep the acetone rinsate separate from 

the toluene rinsate to the extent practicable. Rinsate fractions should be stored separately 

in glass bottles that have been pre-rinsed with acetone, hexane, and toluene (or purchase 

pre-cleaned bottles). 

(3) Use good engineering judgment to determine if you should analyze the aqueous 

condensate phase for SVOCs. If you determine that analysis is necessary, use toluene to 

perform a liquid-liquid extraction of the SVOCs from the collected aqueous condensate 

using a separatory funnel or an equivalent method. Add the toluene from this aqueous 

extraction to the toluene rinsate fraction described in paragraph (a)(2) of this section.

(4) Reduce rinsate solvent volumes as needed using a Kuderna-Danish concentrator or 

rotary evaporator and retain these rinse solvents for reuse during sample media extraction 

for the same test. Be careful to avoid loss of low molecular weight analytes when 

concentrating with rotary evaporation.

(b) Sample extraction. Extract the SVOCs from the sorbent using Soxhlet extraction as 

described in this paragraph (b). Two 16 hour extractions are necessary to accommodate 

the Soxhlet extractions of all SVOCs from a single sample. This reduces the possibility

of losing low molecular weight SVOCs and promotes water removal. We recommend 

performing the first extraction with acetone/hexane and the second using toluene (or an 

equivalent solvent system). You may alternatively use an equivalent method such as an 

automated solvent extractor.

(1) We recommend equipping the Soxhlet extractor with a Dean-Stark trap to facilitate 

removal of residual water from the sampling system rinse. The Soxhlet apparatus must 

be large enough to allow extraction of the PUF, XAD-2, and filter in a single batch. 

Include in the extractor setup a glass thimble with a coarse or extra coarse sintered glass 

bottom. Pre-clean the extractor using proper glass-cleaning procedures. We recommend 

that the Soxhlet apparatus be cleaned with a (4 to 8) hour Soxhlet extraction with 

methylene chloride at a cycling rate of three cycles per hour. Discard the solvent used for 

pre-cleaning (no analysis is necessary).

(2) Load the extractor thimble before placing it in the extractor by first rolling the PM 

filter around the inner circumference of the thimble, with the sampled side facing in. 

Push one PUF plug down into the bottom of the thimble, add approximately half of the 

XAD-2, and then spike the XAD-2 in the thimble with the isotopically labeled extraction 

standards of known mass. Target the center of the XAD-2 bed for delivering the 

extraction standard. We recommend using multiple isotopically labeled extraction 

standards that cover the range of target analytes. This generally means that you should 

use isotopically labeled standards at least for the lowest and highest molecular weight 

analytes for each category of compounds (such as PAHs and dioxins). These extraction 

standards monitor the efficiency of the extraction and are also used to determine analyte 

concentrations after analysis. Upon completion of spiking, add the remaining XAD-2 to 

the thimble, insert the remaining PUF plug, and place the thimble into the extractor. Note 
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that if you are collecting and analyzing for SVOCs in gas and particle phases, perform 

separate extractions for the filter and XAD-2.

(3) For the initial extraction, combine the concentrated acetone rinses (from the sampling 

system in paragraph (a) of this section) with enough hexane to bring the solvent volume 

up to the target level of 700 ml. Assemble the extractor and turn on the heating controls 

and cooling water. Allow the sample to reflux for 16 hours with the rheostat adjusted to 

cycle the extraction at a rate of (3.0 ±0.5) cycles per hour. Drain the water from the 

Dean-Stark trap as it accumulates by opening the stopcock on the trap. Set aside the 

water for analysis or discard it. In most cases, any water present will be removed within 

approximately 2 hours after starting the extraction.

(4) After completing the initial extraction, remove the solvent and concentrate it to (4.0 

±0.5) ml using a Kuderna-Danish concentrator that includes a condenser such as a threeball Snyder column with venting dimples and a graduated collection tube. Using this 

concentrator will minimize evaporative loss of analytes with lower molecular weight.

(i) Rinse the round bottom flask of the extractor with (60 to 100) ml of hexane and add 

the rinsate to this concentrated extract.

(ii) Concentrate the mixture to (4 ±0.5) ml using a Kuderna-Danish concentrator or 

similar apparatus.

(iii) Repeat the steps in paragraphs (b)(4)(i) and (ii) of this section three times, or as 

necessary to remove all the residual solvent from the round bottom flask of the extractor, 

concentrating the final rinsate to (4 ±0.5) ml.

(5) For the second extraction, combine the toluene rinses (from the sampling system in 

paragraph (a) of this section) with any additional toluene needed to bring the solvent 

volume up to the target level of 700 ml. As noted in paragraph (a) of this section, you 

may need to concentrate the rinsate before adding it to the extraction apparatus if the 

rinsate solvent volume is too large. Allow the sample to reflux for 16 hours with the 

rheostat adjusted to cycle the extraction at a rate of (3.0 ±0.5) cycles per hour. Check the 

Dean-Stark trap for water during the first 2 hours of the extraction (though little or no 

water should be present during this stage).

(6) Upon completion of the second extraction, remove the solvent and concentrate it to (4 

±0.5) ml as described in paragraph (b)(4) of this section. Using hexane from paragraph 

(b)(4) of this section as the rinse solvent effectively performs a solvent exchange of 

toluene with hexane.

(7) Combine the concentrated extract from paragraph (b)(4) of this section with the 

concentrated extract from paragraph (b)(6) of this section. Divide the extract into a 

number of fractions based on the number of analyses you need to perform. Perform the 

separate sample clean-up described in paragraph (c) of this section as needed for each 

fraction.

(c) Sample clean-up. This paragraph (c) describes how to perform sample cleaning to 

remove from the sample extract any solids and any SVOCs that will not be analyzed. 

This process, known as “sample clean-up”, reduces the potential for interference or coelution of peaks during analytical analysis. Before performing the sample clean-up, spike 

the extract with an alternate standard that contains a known mass of isotopically labeled 

compounds that are identical to the target analytes (except for the labeling). The category
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of the target analyte compounds (such as PAHs or dioxin) will determine the number of 

compounds that make up the standard. For example, PAHs require the use of four 

compounds in the alternate standard to cover the four basic ring structures of PAHs (2-

ring, 3-ring, 4-ring, and 5-ring structures). These alternate standards are used to monitor 

the efficiency of the clean-up procedure. Before sample clean-up, concentrate the 

fractionated sample to about 2 ml with a Kuderna-Danish concentrator or rotary

evaporator, and then transfer the extract to an 8 ml test tube with hexane rinse. 

Concentrate it to a volume of about 1 ml using a Kuderna-Danish concentrator. Use good 

engineering judgment to select an appropriate column chromatographic clean-up option 

for your target analytes. Note that these clean-up techniques generally remove 

compounds based on their polarity. The following procedures are examples of clean-up 

techniques for PAHs and nPAHs.

(1) PAH clean-up. The following method is appropriate for clean-up of extracts intended 

for analysis of PAHs:

(i) Pack a glass gravity column (250 mm x 10 mm recommended) by inserting a clean 

glass wool plug into the bottom of the column and add 10 g of activated silica gel in 

methylene chloride. Tap the column to settle the silica gel and then add a 1 cm layer of 

anhydrous sodium sulfate. Verify the volume of solvent required to completely elute all 

the PAHs and adjust the weight of the silica gel accordingly to account for variations 

among batches of silica gel that may affect the elution volume of the various PAHs.

(ii) Elute the column with 40 ml of hexane. The rate for all elutions should be about 2 

ml/min. You may increase the elution rate by using dry air or nitrogen to maintain the 

headspace slightly above atmospheric pressure. Discard the eluate just before exposing 

the sodium sulfate layer to the air or nitrogen and transfer the 1 ml sample extract onto 

the column using two additional 2 ml rinses of hexane. Just before exposing the sodium 

sulfate layer to the air or nitrogen, begin elution of the column with 25 ml of hexane 

followed by 25 ml of 40 volume % methylene chloride in hexane. Collect the entire 

eluate and concentrate it to about 5 ml using the Kuderna-Danish concentrator or a rotary

evaporator. Make sure not to evaporate all the solvent from the extract during the 

concentration process. Transfer the eluate to a small sample vial using a hexane rinse and 

concentrate it to 100 μl using a stream of nitrogen without violently disturbing the 

solvent. Store the extracts in a refrigerator at or below 4 °C, and away from light.

(2) nPAH clean up. The following procedure, adapted from “Determination and 

Comparison of Nitrated-Polycyclic Aromatic Hydrocarbons Measured in Air and Diesel 

Particulate Reference Materials” (Bamford, H.A., et al, Chemosphere, Vol. 50, Issue 5, 

pages 575 – 587), is an appropriate method to clean up extracts intended for analysis of 

nPAHs:

(i) Condition an aminopropyl solid phase extraction (SPE) cartridge by eluting it with 20 

ml of 20 volume % methylene chloride in hexane. Transfer the extract quantitatively to 

the SPE cartridge with at least two methylene chloride rinses. Elute the extract through 

the SPE cartridge by using 40 ml of 20 volume % methylene chloride in hexane to 

minimize potential interference of polar constituents, and then reduce the extract to 0.5 

ml in hexane and subject it to normal-phase liquid chromatography using a pre-prepared 

9.6 mm x 25 cm semi-preparative Chromegabond®amino/cyano column (5 μm particle 
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size) to isolate the nPAH fraction. The mobile phase is 20 volume % methylene chloride 

in hexane at a constant flow rate of 5 ml per minute. Back-flash the column with 60 ml 

of methylene chloride and then condition it with 200 ml of 20 volume % methylene 

chloride in hexane before each injection. Collect the effluent and concentrate it to about 

2 ml using the Kuderna-Danish concentrator or a rotary evaporator. Transfer it to a 

minivial using a hexane rinse and concentrate it to 100 μl using a gentle stream of 

nitrogen. Store the extracts at or below 4 °C, and away from light.

(ii) [Reserved]

§ 1065.1111 Sample analysis.

This subpart does not specify chromatographic or analytical methods to analyze extracts, 

because the appropriateness of such methods is highly dependent on the nature of the 

target analytes. However, we recommend that you spike the extract with an injection 

standard that contains a known mass of an isotopically labeled compound that is identical 

to one of the target analytes (except for labeling). This injection standard allows you to 

monitor the efficiency of the analytical process by verifying the volume of sample 

injected for analysis.

331. Part 1066 is revised to read as follows:

Part 1066—VEHICLE-TESTING PROCEDURES

Subpart A—APPLICABILITY AND GENERAL PROVISIONS

Sec.

1066.1 Applicability.

1066.2 Submitting information to EPA under this part.

1066.5 Overview of this part 1066 and its relationship to the standard-setting part.

1066.10 Other procedures.

1066.15 Overview of test procedures.

1066.20 Units of measure and overview of calculations.

1066.25 Recordkeeping.

Subpart B—EQUIPMENT, MEASUREMENT INSTRUMENTS, FUEL, AND 

ANALYTICAL GAS SPECIFICATIONS

1066.101 Overview.

1066.105 Ambient controls and vehicle cooling fans.

1066.110 Equipment specifications for emission sampling systems.

1066.120 Measurement instruments.

1066.125 Data updating, recording, and control.

1066.130 Measurement instrument calibrations and verifications.

1066.135 Linearity verification.

1066.140 Diluted exhaust flow calibration.

1066.145 Test fuel, engine fluids, analytical gases, and other calibration standards.

1066.150 Analyzer interference and quench verification limit.
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Subpart C—DYNAMOMETER SPECIFICATIONS

1066.201 Dynamometer overview.

1066.210 Dynamometers.

1066.215 Summary of verification procedures for chassis dynamometers.

1066.220 Linearity verification for chassis dynamometer systems.

1066.225 Roll runout and diameter verification procedure.

1066.230 Time verification procedure.

1066.235 Speed verification procedure.

1066.240 Torque transducer verification.

1066.245 Response time verification.

1066.250 Base inertia verification.

1066.255 Parasitic loss verification.

1066.260 Parasitic friction compensation evaluation.

1066.265 Acceleration and deceleration verification.

1066.270 Unloaded coastdown verification.

1066.275 Daily dynamometer readiness verification.

1066.290 Verification of speed accuracy for the driver’s aid.

Subpart D—COASTDOWN

1066.301 Overview of coastdown procedures.

1066.305 Coastdown procedures for motor vehicles at or below 14,000 pounds GVWR.

1066.310 Coastdown procedures for vehicles above 14,000 pounds GVWR.

1066.315 Dynamometer road-load setting.

Subpart E—PREPARING VEHICLES AND RUNNING AN EXHAUST 

EMISSION TEST

1066.401 Overview.

1066.405 Vehicle preparation and preconditioning.

1066.410 Dynamometer test procedure.

1066.415 Vehicle operation.

1066.420 Test preparation.

1066.425 Performing emission tests.

Subpart F—ELECTRIC VEHICLES AND HYBRID ELECTRIC VEHICLES

1066.501 Overview.

Subpart G—CALCULATIONS

1066.601 Overview.

1066.605 Mass-based and molar-based exhaust emission calculations.

1066.610 Dilution air background correction.

1066.615 NOx intake-air humidity correction.

1066.620 Removed water correction.

1066.625 Flow meter calibration calculations.

1066.630 PDP, SSV, and CFV flow rate calculations.
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1066.635 NMOG determination.

1066.695 Data requirements.

Subpart H—COLD TEMPERATURE TEST PROCEDURES

1066.701 Applicability and general provisions.

1066.710 Cold temperature testing procedures for measuring CO and NMHC emissions 

and determining fuel economy.

Subpart I—EXHAUST EMISSION TEST PROCEDURES FOR MOTOR 

VEHICLES

1066.801 Applicability and general provisions.

1066.805 Road-load power, test weight, and inertia weight class determination.

1066.810 Vehicle preparation.

1066.815 Exhaust emission test procedures for FTP testing.

1066.816 Vehicle preconditioning for FTP testing.

1066.820 Composite calculations for FTP exhaust emissions.

1066.830 Supplemental Federal Test Procedures; overview.

1066.831 Exhaust emission test procedures for aggressive driving.

1066.835 Exhaust emission test procedure for SC03 emissions.

1066.840 Highway fuel economy test procedure.

1066.845 AC17 Air conditioning efficiency test procedure.

Subpart J—EVAPORATIVE EMISSION TEST PROCEDURES

§ 1066.901 Applicability and general provisions.

TEST EQUIPMENT AND CALCULATIONS FOR EVAPORATIVE AND REFUELING EMISSIONS

1066.910 SHED enclosure specifications.

1066.915 Enclosures; auxiliary systems and equipment.

1066.920 Enclosure calibrations.

1066.925 Enclosure calculations for evaporative and refueling emissions.

1066.930 Equipment for point-source measurement of running losses.

EVAPORATIVE AND REFUELING EMISSION TEST PROCEDURES FOR MOTOR VEHICLES

1066.950 Fuel temperature profile.

1066.955 Diurnal emission test.

1066.960 Running loss test.

1066.965 Hot soak test.

1066.970 Refueling test for liquid fuels.

1066.971 Vehicle and canister preconditioning for the refueling test.

1066.975 Refueling test for LPG.

1066.980 Fuel dispensing spitback procedure.

1066.985 Fuel storage system leak test procedure.

Subpart K—DEFINITIONS AND OTHER REFERENCE MATERIAL

1066.1001 Definitions.

1066.1005 Symbols, abbreviations, acronyms, and units of measure.
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1066.1010 Incorporation by reference.

Authority: 42 U.S.C. 7401-7671q.

Subpart A—APPLICABILITY AND GENERAL PROVISIONS

§ 1066.1 Applicability.

(a) This part describes the emission measurement procedures that apply to testing we 

require for the following vehicles:

(1) Model year 2014 and later heavy-duty highway vehicles we regulate under 40 CFR 

part 1037 that are not subject to chassis testing for exhaust emissions under 40 CFR part 

86.

(2) Model year 2022 and later motor vehicles (light-duty and heavy-duty) that are subject 

to chassis testing for exhaust emissions under 40 CFR part 86, other than highway

motorcycles. See 40 CFR part 86 for provisions describing how to implement this part 

1066.

(b) The procedures of this part may apply to other types of vehicles, as described in this 

part and in the standard-setting part.

(c) The testing in this part 1066 is designed for measuring exhaust, evaporative, and 

refueling emissions. Procedures for measuring evaporative and refueling emissions for 

motor vehicles are in some cases integral with exhaust measurement procedures as 

described in § 1066.801. Subpart J of this part describes provisions that are unique to 

evaporative and refueling emission measurements. Other subparts in this part are written 

with a primary focus on measurement of exhaust emissions.

(d) The term “you” means anyone performing testing under this part other than EPA. 

(1) This part is addressed primarily to manufacturers of vehicles, but it applies equally to 

anyone who does testing under this part for such manufacturers. 

(2) This part applies to any manufacturer or supplier of test equipment, instruments, 

supplies, or any other goods or services related to the procedures, requirements, 

recommendations, or options in this part. 

(e) Paragraph (a) of this section identifies the parts of the CFR that define emission 

standards and other requirements for particular types of vehicles. In this part, we refer to 

each of these other parts generically as the “standard-setting part.” For example, 40 CFR 

part 1037 is the standard-setting part for heavy-duty highway vehicles and parts 86 and 

600 are the standard-setting parts for light-duty vehicles. For vehicles subject to 40 CFR 

part 86, subpart S, treat subpart I and subpart J of this part as belonging to 40 CFR part 

86. This means that references to the standard-setting part include subpart I and subpart J 

of this part.

(f) Unless we specify otherwise, the terms “procedures” and “test procedures” in this part 

include all aspects of vehicle testing, including the equipment specifications, calibrations, 

calculations, and other protocols and procedural specifications needed to measure 

emissions.

(g) For additional information regarding these test procedures, visit our Web site at 

www.epa.gov, and in particular http://www.epa.gov/nvfel/testing/regulations.htm.
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§ 1066.2 Submitting information to EPA under this part.

(a) You are responsible for statements and information in your applications for 

certification, requests for approved procedures, selective enforcement audits, laboratory

audits, production-line test reports, or any other statements you make to us related to this 

part 1066. If you provide statements or information to someone for submission to EPA, 

you are responsible for these statements and information as if you had submitted them to 

EPA yourself.

(b) In the standard-setting part and in 40 CFR 1068.101, we describe your obligation to 

report truthful and complete information and the consequences of failing to meet this 

obligation. See also 18 U.S.C. 1001 and 42 U.S.C. 7413(c)(2). This obligation applies 

whether you submit this information directly to EPA or through someone else.

(c) We may void any certificates or approvals associated with a submission of 

information if we find that you intentionally submitted false, incomplete, or misleading 

information. For example, if we find that you intentionally submitted incomplete 

information to mislead EPA when requesting approval to use alternate test procedures, 

we may void the certificates for all engine families certified based on emission data 

collected using the alternate procedures. This would also apply if you ignore data from 

incomplete tests or from repeat tests with higher emission results.

(d) We may require an authorized representative of your company to approve and sign 

the submission, and to certify that all the information submitted is accurate and complete. 

This includes everyone who submits information, including manufacturers and others.

(e) See 40 CFR 1068.10 for provisions related to confidential information. Note however 

that under 40 CFR 2.301, emission data are generally not eligible for confidential 

treatment.

(f) Nothing in this part should be interpreted to limit our ability under Clean Air Act 

section 208 (42 U.S.C. 7542) to verify that vehicles conform to the regulations.

§ 1066.5 Overview of this part 1066 and its relationship to the standard-setting part.

(a) This part specifies procedures that can apply generally to testing various categories of

vehicles. See the standard-setting part for directions in applying specific provisions in 

this part for a particular type of vehicle. Before using this part’s procedures, read the 

standard-setting part to answer at least the following questions:

(1) What drive schedules must I use for testing?

(2) Should I warm up the test vehicle before measuring emissions, or do I need to 

measure cold-start emissions during a warm-up segment of the duty cycle?

(3) Which exhaust constituents do I need to measure? Measure all exhaust constituents 

that are subject to emission standards, any other exhaust constituents needed for 

calculating emission rates, and any additional exhaust constituents as specified in the 

standard-setting part. See 40 CFR 1065.5 regarding requests to omit measurement of 

N2O and CH4 for vehicles not subject to an N2O or CH4 emission standard.

(4) Do any unique specifications apply for test fuels?

(5) What maintenance steps may I take before or between tests on an emission-data 

vehicle?
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(6) Do any unique requirements apply to stabilizing emission levels on a new vehicle?

(7) Do any unique requirements apply to test limits, such as ambient temperatures or 

pressures?

(8) What requirements apply for evaporative and refueling emissions?

(9) Are there any emission standards specified at particular operating conditions or 

ambient conditions?

(10) Do any unique requirements apply for durability testing?

(b) The testing specifications in the standard-setting part may differ from the 

specifications in this part. In cases where it is not possible to comply with both the 

standard-setting part and this part, you must comply with the specifications in the 

standard-setting part. The standard-setting part may also allow you to deviate from the 

procedures of this part for other reasons.

(c) The following table shows how this part divides testing specifications into subparts:

TABLE 1 OF § 1066.5—DESCRIPTION OF PART 1066 SUBPARTS

This subpart Describes these specifications or procedures

Subpart A Applicability and general provisions.

Subpart B Equipment for testing.

Subpart C Dynamometer specifications.

Subpart D Coastdowns for testing.

Subpart E How to prepare your vehicle and run an emission test.

Subpart F How to test electric vehicles and hybrid electric vehicles.

Subpart G Test procedure calculations.

Subpart H Cold temperature testing.

Subpart I Exhaust emission test procedures for motor vehicles.

Subpart J Evaporative and refueling emission test procedures.

Subpart K Definitions and reference material.

§ 1066.10 Other procedures.

(a) Your testing. The procedures in this part apply for all testing you do to show 

compliance with emission standards, with certain exceptions noted in this section. In 

some other sections in this part, we allow you to use other procedures (such as less 

precise or less accurate procedures) if they do not affect your ability to show that your 

vehicles comply with the applicable emission standards. This generally requires emission 

levels to be far enough below the applicable emission standards so that any errors caused 

by greater imprecision or inaccuracy do not affect your ability to state unconditionally

that the engines meet all applicable emission standards.

(b) Our testing. These procedures generally apply for testing that we do to determine if 

your vehicles comply with applicable emission standards. We may perform other testing 

as allowed by the Act.

(c) Exceptions. We may allow or require you to use procedures other than those 

specified in this part as described in 40 CFR 1065.10(c). All the test procedures noted as 

exceptions to the specified procedures are considered generically as "other procedures." 

Note that the terms "special procedures" and "alternate procedures" have specific 
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meanings; "special procedures" are those allowed by 40 CFR 1065.10(c)(2) and 

"alternate procedures" are those allowed by 40 CFR 1065.10(c)(7). If we require you to 

request approval to use other procedures under this paragraph (c), you may not use them 

until we approve your request.

§ 1066.15 Overview of test procedures.

This section outlines the procedures to test vehicles that are subject to emission standards.

(a) The standard-setting part describes the emission standards that apply. Evaporative 

and refueling emissions are generally in the form of grams total hydrocarbon equivalent 

per test. We set exhaust emission standards in g/mile (or g/km), for the following 

constituents:

(1) Total oxides of nitrogen, NOx.

(2) Hydrocarbons, HC, which may be expressed in the following ways:

(i) Total hydrocarbons, THC.

(ii) Nonmethane hydrocarbons, NMHC, which results from subtracting methane, CH4, 

from THC.

(iii) Total hydrocarbon-equivalent, THCE, which results from adjusting THC 

mathematically to be equivalent on a carbon-mass basis.

(iv) Nonmethane hydrocarbon-equivalent, NMHCE, which results from adjusting NMHC 

mathematically to be equivalent on a carbon-mass basis.

(v) Nonmethane organic gases, NMOG, which are calculated either from fully or partially

speciated measurement of hydrocarbons including oxygenates, or by adjusting measured 

NMHC values based on fuel oxygenate properties.

(3) Particulate matter, PM.

(4) Carbon monoxide, CO.

(5) Carbon dioxide, CO2.

(6) Methane, CH4.

(7) Nitrous oxide, N2O.

(8) Formaldehyde, CH2O. 

(b) Note that some vehicles may not be subject to standards for all the exhaust emission 

constituents identified in paragraph (a) of this section. Note also that the standard-setting 

part may include standards for pollutants not listed in paragraph (a) of this section.

(c) The provisions of this part apply for chassis dynamometer testing where vehicle speed 

is controlled to follow a prescribed duty cycle while simulating vehicle driving through 

the dynamometer’s road-load settings. We generally set exhaust emission standards over 

test intervals and/or drive schedules, as follows:

(1) Vehicle operation. Testing involves measuring emissions and miles travelled while 

operating the vehicle on a chassis dynamometer. Refer to the definitions of “duty cycle” 

and “test interval” in § 1066.1001. Note that a single drive schedule may have multiple 

test intervals and require weighting of results from multiple test intervals to calculate a 

composite distance-based emission value to compare to the standard.

(2) Constituent determination. Determine the total mass of each exhaust constituent over 

a test interval by selecting from the following methods:
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(i) Continuous sampling. In continuous sampling, measure the exhaust constituent’s 

concentration continuously from raw or dilute exhaust. Multiply this concentration by

the continuous (raw or dilute) flow rate at the emission sampling location to determine 

the constituent’s flow rate. Sum the constituent’s flow rate continuously over the test 

interval. This sum is the total mass of the emitted constituent.

(ii) Batch sampling. In batch sampling, continuously extract and store a sample of raw or 

dilute exhaust for later measurement. Extract a sample proportional to the raw or dilute 

exhaust flow rate, as applicable. You may extract and store a proportional sample of 

exhaust in an appropriate container, such as a bag, and then measure NOx, HC, CO, CO2, 

CH4, N2O, and CH2O concentrations in the container after the test interval. You may 

deposit PM from proportionally extracted exhaust onto an appropriate substrate, such as a 

filter. In this case, divide the PM by the amount of filtered exhaust to calculate the PM 

concentration. Multiply batch sampled concentrations by the total (raw or dilute) flow 

from which it was extracted during the test interval. This product is the total mass of the 

emitted constituent.

(iii) Combined sampling. You may use continuous and batch sampling simultaneously

during a test interval, as follows:

(A) You may use continuous sampling for some constituents and batch sampling for 

others.

(B) You may use continuous and batch sampling for a single constituent, with one being 

a redundant measurement, subject to the provisions of 40 CFR 1065.201. 

(d) Refer to subpart G of this part and the standard-setting part for calculations to 

determine g/mile emission rates.

(e) You must use good engineering judgment for all aspects of testing under this part. 

While this part highlights several specific cases where good engineering judgment is 

especially relevant, the requirement to use good engineering judgment is not limited to 

those provisions where we specifically re-state this requirement.

§ 1066.20 Units of measure and overview of calculations.

(a) System of units. The procedures in this part follow both conventional English units 

and the International System of Units (SI), as detailed in NIST Special Publication 811, 

which we incorporate by reference in § 1066.1010. Except where specified, equations 

work with either system of units. Where the equations depend on the use of specific 

units, the regulation identifies the appropriate units.

(b) Units conversion. Use good engineering judgment to convert units between 

measurement systems as needed. For example, if you measure vehicle speed as 

kilometers per hour and we specify a precision requirement in terms of miles per hour, 

convert your measured kilometer per hour value to miles per hour before comparing it to 

our specification. The following conventions are used throughout this document and 

should be used to convert units as applicable:

(1) 1 hp = 33,000 ft∙lbf/min = 550 ft∙lbf/s = 0.7457 kW.

(2) 1 lbf = 32.174 ft∙lbm/s2 = 4.4482 N.

(3) 1 inch = 25.4 mm.

(4) 1 mile = 1609.344 m.
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(5) For ideal gases, 1 μmol/mol = 1 ppm.

(6) For ideal gases, 10 mmol/mol = 1 %.

(c) Temperature. We generally designate temperatures in units of degrees Celsius (°C) 

unless a calculation requires an absolute temperature. In that case, we designate 

temperatures in units of Kelvin (K). For conversion purposes throughout this part, 0 °C 

equals 273.15 K. Unless specified otherwise, always use absolute temperature values for 

multiplying or dividing by temperature. 

(d) Absolute pressure. Measure absolute pressure directly or calculate it as the sum of 

atmospheric pressure plus a differential pressure that is referenced to atmospheric 

pressure. Always use absolute pressure values for multiplying or dividing by pressure.

(e) Rounding. The rounding provisions of 40 CFR 1065.20 apply for calculations in this 

part. This generally specifies that you round final values but not intermediate values. 

Use good engineering judgment to record the appropriate number of significant digits for 

all measurements.

(f) Interpretation of ranges. Interpret a range as a tolerance unless we explicitly identify

it as an accuracy, repeatability, linearity, or noise specification. See 40 CFR 1065.1001 

for the definition of tolerance. In this part, we specify two types of ranges:

(1) Whenever we specify a range by a single value and corresponding limit values above 

and below that value (such as X ±Y), target the associated control point to that single 

value (X). Examples of this type of range include “±10 % of maximum pressure”, or 

“(30 ±10) kPa”. In these examples, you would target the maximum pressure or 30 kPa, 

respectively.

(2) Whenever we specify a range by the interval between two values, you may target any 

associated control point to any value within that range. An example of this type of range 

is “(40 to 50) kPa”.

(g) Scaling of specifications with respect to an applicable standard. Because this part 

1066 applies to a wide range of vehicles and emission standards, some of the 

specifications in this part are scaled with respect to a vehicle’s applicable standard or 

weight. This ensures that the specification will be adequate to determine compliance, but 

not overly burdensome by requiring unnecessarily high-precision equipment. Many of 

these specifications are given with respect to a “flow-weighted mean” that is expected at 

the standard or during testing. Flow-weighted mean is the mean of a quantity after it is 

weighted proportional to a corresponding flow rate. For example, if a gas concentration 

is measured continuously from the raw exhaust of an engine, its flow-weighted mean 

concentration is the sum of the products of each recorded concentration times its 

respective exhaust flow rate, divided by the sum of the recorded flow rates. As another 

example, the bag concentration from a CVS system is the same as the flow-weighted 

mean concentration, because the CVS system itself flow-weights the bag concentration.

§ 1066.25 Recordkeeping.

(a) The procedures in this part include various requirements to record data or other 

information. Refer to the standard-setting part and § 1066.695 regarding specific 

recordkeeping requirements. 
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(b) You must promptly send us organized, written records in English if we ask for them. 

We may review them at any time.

(c) We may waive specific reporting or recordkeeping requirements we determine to be 

unnecessary for the purposes of this part and the standard-setting part. Note that while 

we will generally keep the records required by this part, we are not obligated to keep 

records we determine to be unnecessary for us to keep. For example, while we require 

you to keep records for invalid tests so we may verify that your invalidation was 

appropriate, it is not necessary for us to keep records for our own invalid tests.

Subpart B—EQUIPMENT, MEASUREMENT INSTRUMENTS, FUEL, AND 

ANALYTICAL GAS SPECIFICATIONS

§ 1066.101 Overview.

(a) This subpart addresses equipment related to emission testing, as well as test fuels and 

analytical gases.

(b) The provisions of 40 CFR part 1065 specify engine-based procedures for measuring 

emissions. Except as specified otherwise in this part, the provisions of 40 CFR part 1065 

apply for testing required by this part as follows:

(1) The provisions of 40 CFR part 1065, subpart B, describe equipment specifications for 

exhaust dilution and sampling systems; these specifications apply for testing under this 

part as described in § 1066.110. 

(2) The provisions of 40 CFR part 1065, subpart C, describe specifications for 

measurement instruments; these specifications apply for testing under this part as 

described in § 1066.120.

(3) The provisions of 40 CFR part 1065, subpart D, describe specifications for 

measurement instrument calibrations and verifications; these specifications apply for 

testing under this part as described in § 1066.130.

(4) The provisions of 40 CFR part 1065, subpart H, describe specifications for fuels, 

engine fluids, and analytical gases; these specifications apply for testing under this part as 

described in § 1066.145.

(5) The provisions of 40 CFR part 1065, subpart I, describe specifications for testing with 

oxygenated fuels; these specifications apply for NMOG determination as described in § 

1066.635.

(c) The provisions of this subpart are intended to specify systems that can very accurately 

and precisely measure emissions from motor vehicles such as light-duty vehicles. To the 

extent that this level of accuracy or precision is not necessary for testing highway

motorcycles or nonroad vehicles, we may waive or modify the specifications and 

requirements of this part for testing these other vehicles, consistent with good 

engineering judgment. For example, it may be appropriate to allow the use of a 

hydrokinetic dynamometer that is not able to meet all the performance specifications 

described in this subpart.

§ 1066.105 Ambient controls and vehicle cooling fans.
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(a) Ambient conditions. Dynamometer testing under this part generally requires that you 

maintain the test cell within a specified range of ambient temperature and humidity. Use 

good engineering judgment to maintain relatively uniform temperatures throughout the 

test cell before testing. You are generally not required to maintain uniform temperatures 

throughout the test cell while the vehicle is running due to the heat generated by the 

vehicle. Measured humidity values must represent the conditions to which the vehicle is 

exposed, which includes intake air; other than the intake air, humidity does not affect 

emissions, so humidity need not be uniform throughout the test cell.

(b) General requirements for cooling fans. Use good engineering judgment to select and 

configure fans to cool the test vehicle in a way that meets the specifications of paragraph 

(c) of this section and simulates in-use operation. If you demonstrate that the specified 

fan configuration is impractical for special vehicle designs, such as vehicles with rearmounted engines, or it does not provide adequate cooling to properly represent in-use 

operation, you may ask us to approve increasing fan capacity or using additional fans.

(c) Allowable cooling fans for vehicles at or below 14,000 pounds GVWR. Cooling fan 

specifications for vehicles at or below 14,000 pounds GVWR depend on the test cycle.

Paragraph (c)(1) of this section summarizes the cooling fan specifications for the 

different test cycles; the detailed specifications are described in paragraphs (c)(2) through 

(5) of this section. See § 1066.410 for instruction regarding how to use the fans during 

testing.

(1) Cooling fan specifications for different test cycles are summarized as follows:

(i) For the FTP test cycle, the allowable cooling fan configurations are described in 

paragraphs (c)(2) and (3) of this section.

(ii) For the HFET test cycle, the allowable cooling fan configurations are described in 

paragraphs (c)(2) and (3) of this section.

(iii) For the US06 test cycle, the allowable cooling fan configurations are described in 

paragraphs (c)(2) and (4) of this section.

(iv) For the LA-92 test cycle, the allowable cooling fan configurations are described in 

paragraphs (c)(2) and (4) of this section.

(v) For SC03 and AC17 test cycles, the allowable cooling fan configuration is described 

in paragraph (c)(5) of this section.

(2) You may use a road-speed modulated fan system meeting the specifications of this 

paragraph (c)(2) for anything other than SC03 and AC17 testing. Use a road-speed 

modulated fan that achieves a linear speed of cooling air at the blower outlet that is 

within ±3.0 mph (±1.3 m/s) of the corresponding roll speed when vehicle speeds are 

between 5 and 30 mph, and within ±6.5 mph (±2.9 m/s) of the corresponding roll speed at 

higher vehicle speeds; however you may limit the fan’s maximum linear speed to 70 

mph. We recommend that the cooling fan have a minimum opening of 0.2 m2and a 

minimum width of 0.8 m.

(i) Verify the air flow velocity for fan speeds corresponding to vehicle speeds of 20 and 

40 mph using an instrument that has an accuracy of ±2 % of the measured air flow speed.

(ii) For fans with rectangular outlets, divide the fan outlet into sections as shown in 

Figure 1 of this section. As illustrated by the “+” in the following figure, measure flow 

from the center of each section; do not measure the flow from the center section.
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Figure 1 of § 1066.105—Rectangular fan outlet grid

(iii) For fans with circular outlets, divide the fan outlet into 8 equal sections as shown in 

Figure 2 of this section. As illustrated by the “+” in the following figure, measure flow 

on the radial centerline of each section, at a radius of two-thirds of the fan’s total radius.

Figure 2 of § 1066.105—Circular fan outlet grid

(iv) Verify that the uniformity of the fan’s axial flow is constant across the discharge area 

within a tolerance of ±4.0 mph of the vehicle’s speed at fan speeds corresponding to 20 

mph, and within ±8.0 mph at fan speeds corresponding to 40 mph. For example, at a 

vehicle speed of 20.2 mph, axial flow at all locations denoted by the “+” across the 

discharge nozzle must be between 16.2 and 24.2 mph. When measuring the axial air flow 

velocity, use good engineering judgment to determine the distance from the nozzle outlet 

at each point of the fan outlet grid. Use these values to calculate a mean air flow velocity

across the discharge area at each speed setting. The instrument used to verify the air 

velocity must have an accuracy of ±2 % of the measured air flow velocity.

(v) Use a multi-axis flow meter or another method to verify that the fan’s air flow 

perpendicular to the axial air flow is less than 15% of the axial air flow, consistent with 

good engineering judgment. Demonstrate this by comparing the perpendicular air flow 

velocity to the mean air flow velocities determined in paragraph (c)(2)(iv) of this section 

at vehicle speeds of 20 and 40 mph.

(3) You may use a fixed-speed fan with a maximum capacity up to 2.50 m3/s for FTP and 

HFET testing. 
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(4) You may use a fixed-speed fan with a maximum capacity up to 7.10 m3/s for US06 

and LA-92 testing.

(5) For SC03 and AC17 testing, use a road-speed modulated fan with a minimum 

discharge area that is equal to or exceeds the vehicle’s frontal inlet area. We recommend 

using a fan with a discharge area of 1.7 m2.

(i) Air flow volumes must be proportional to vehicle speed. Select a fan size that will 

produce a flow volume of approximately 45 m3/s at 60 mph. If this fan is also the only

source of test cell air circulation or if fan operational mechanics make the 0 mph air flow 

requirement impractical, air flow of 2 mph or less at 0 mph vehicle speed is allowed.

(ii) Verify the uniformity of the fan’s axial flow as described in paragraph (c)(2)(iv) of 

this section, except that you must measure the axial air flow velocity 60 cm from the 

nozzle outlet at each point of the discharge area grid.

(iii) Use a multi-axis flow meter or another method to verify that the fan’s air flow 

perpendicular to the axial air flow is less than 10% of the axial air flow, consistent with 

good engineering judgment. Demonstrate this by comparing the perpendicular air flow 

velocity to the mean air flow velocities determined in paragraph (c)(2)(iv) of this section 

at vehicle speeds of 20 and 40 mph.

(iv) In addition to the road-speed modulated fan, we may approve the use of one or more 

fixed-speed fans to provide proper cooling to represent in-use operation, but only up to a 

total of 2.50 m3/s for all additional fans.

(d) Allowable cooling fans for vehicles above 14,000 pounds GVWR. For all testing, use 

a road-speed modulated fan system that achieves a linear speed of cooling air at the 

blower outlet that is within ±3.0 mph (±1.3 m/s) of the corresponding roll speed when 

vehicle speeds are between 5 and 30 mph, and within ±10 mph (±4.5 m/s) of the 

corresponding roll speed at higher vehicle speeds. For vehicles above 19,500 pounds 

GVWR, we recommend that the cooling fan have a minimum opening of 2.75 m2, a 

minimum flow rate of 60 m3/s at a fan speed of 50 mph, and a minimum speed profile in 

the free stream flow, across the duct, that is ±15 % of the target flow rate.

§ 1066.110 Equipment specifications for emission sampling systems.

(a) This section specifies equipment related to emission testing, other than measurement 

instruments. This equipment includes dynamometers (described further in subpart C of 

this part) and various emission-sampling hardware.

(b) The following equipment specifications apply for testing under this part:

(1) Connect a vehicle’s exhaust system to any dilution stage as follows:

(i) Minimize lengths of laboratory exhaust tubing. You may use a total length of 

laboratory exhaust tubing up to 4 m without needing to heat or insulate the tubing. 

However, you may use a total length of laboratory exhaust tubing up to 10 m if you 

insulate and/or heat the tubing to minimize the temperature difference between the 

exhaust gas and the whole tubing wall over the course of the emission test. The 

laboratory exhaust tubing starts at the end of the vehicle’s tailpipe and ends at the first 

sample point or the first dilution point. The laboratory exhaust tubing may include 

flexible sections, but we recommend that you limit the amount of flexible tubing to the 

extent practicable. For multiple-tailpipe configurations where the tailpipes combine into
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a single flow path for emission sampling, the start of the laboratory exhaust tubing may

be taken at the last joint where the exhaust flow first becomes a single, combined flow.

(ii) You may insulate or heat any laboratory exhaust tubing. 

(iii) Use laboratory exhaust tubing materials that are smooth-walled and not chemically

reactive with exhaust constituents. (For purposes of this paragraph (b)(1), nominally

smooth spiral-style and accordion-style flexible tubing are considered to be smoothwalled.) For measurements involving PM, tubing materials must also be electrically 

conductive. Stainless steel is an acceptable material for any testing. You may use short 

sections of nonconductive flexible tubing to connect a PM sampling system to the 

vehicle’s tailpipe; use good engineering judgment to limit the amount of nonconductive 

surface area exposed to the vehicle’s exhaust.

(iv) We recommend that you use laboratory exhaust tubing that has either a wall 

thickness of less than 2 mm or is air gap-insulated to minimize temperature differences 

between the wall and the exhaust.

(v) You must seal your system to the extent necessary to ensure that any remaining leaks 

do not affect your ability to demonstrate compliance with the applicable standards. We 

recommend that you seal all known leaks.

(vi) Electrically ground the entire exhaust system, with the exception of nonconductive 

flexible tubing, as allowed under paragraph (b)(1)(iii) of this section.

(vii) For vehicles with multiple tailpipes, route the exhaust into a single flow. To ensure 

mixing of the multiple exhaust streams before emission sampling, we recommend a 

minimum Reynolds number, Re#, of 4000 for the combined exhaust stream, where Re#is 

based on the inside diameter of the combined flow at the first sampling point. You may

configure the exhaust system with turbulence generators, such as orifice plates or fins, to 

achieve good mixing; this may be necessary for good mixing if Re#is less than 4000. Re#

is defined in 40 CFR 1065.640.

(2) Use equipment specifications in 40 CFR 1065.140 through 40 CFR 1065.190, except 

as follows:

(i) For PM background measurement, the following provisions apply instead of the 

analogous provisions in 40 CFR 1065.140(b):

(A) You need not measure PM background for every test. You may apply PM 

background correction for a single site or multiple sites using a moving-average 

background value as long as your background PM sample media (e.g., filters) were all 

made by the same manufacturer from the same material. Use good engineering judgment 

to determine how many background samples make up the moving average and how 

frequently to update those values. For example, you might take one background sample 

per week and average that sample into previous background values, maintaining five 

observations for each calculated average value. Background sampling time should be 

representative of the duration of the test interval to which the background correction is 

applied.

(B) You may sample background PM from the dilution tunnel at any time before or after 

an emission test using the same sampling system used during the emission test. For this 

background sampling, the dilution tunnel blower must be turned on, the vehicle must be 
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disconnected from the laboratory exhaust tubing, and the laboratory exhaust tubing must 

be capped.

(C) The duration of your background sample may be different than that of the test cycle 

in which you are applying the background correction, consistent with good engineering 

judgment.

(D) Your PM background correction may not exceed 5 μg or 5 % of the net PM mass 

expected at the standard, whichever is greater.

(ii) The provisions of 40 CFR 1065.140(d)(2)(iv) do not apply.

(iii) For PM samples, configure dilution systems using the following limits:

(A) Control the dilution air temperature as described in 40 CFR 1065.140(e)(1), except 

that the temperature may be set to (15 to 52) °C. Use good engineering judgment to 

control PM sample temperature as required under 40 CFR 1065.140(e)(4).

(B) Apply the provisions of this paragraph (b)(2)(iii)(B) instead of 40 CFR 

1065.140(e)(2). Add dilution air to the raw exhaust such that the overall dilution factor 

of diluted exhaust to raw exhaust, as shown in Eq. 1066.610-2 or 1066.610-3, is within 

the range of (7:1 to 20:1). Compliance with this dilution factor range may be determined 

for an individual test interval or as a time-weighted average over the entire duty cycle as 

determined in Eq. 1066.610-4. The maximum dilution factor limit of 20:1 does not apply

for hybrid electric vehicles (HEVs), since the dilution factor is infinite when the engine is 

off; however we strongly recommend that you stay under the specified maximum dilution 

factor limit when the engine is running. For partial-flow sampling systems, determine 

dilution factor using Eq. 1066.610-3. To determine the overall dilution factor for PM 

samples utilizing secondary dilution air, multiply the dilution factor from the CVS by the 

dilution ratio of secondary dilution air to primary diluted exhaust.

(iv) In addition to the allowances in 40 CFR 1065.140(c)(6), you may heat the dilution air 

as described in paragraph (b)(2)(iii)(A) of this section to prevent or limit aqueous 

condensation.

(v) If you choose to dilute the exhaust by using a remote mix tee, which dilutes the 

exhaust at the tailpipe, you may use the following provisions consistent with good 

engineering judgment, as long as they do not affect your ability to demonstrate 

compliance with the applicable standards:

(A) You may use smooth-walled flexible tubing (including accordion-style) in the 

dilution tunnel upstream of locations for flow measurement or gaseous emission 

measurement.

(B) You may use smooth-walled electrically conductive flexible tubing in the dilution 

tunnel upstream of the location for PM emission measurements.

(C) All inside surfaces upstream of emission sampling must be made of 300 series 

stainless steel or polymer-based materials.

(D) Use good engineering judgment to ensure that the materials you choose do not cause 

significant loss of PM from your sample.

(vi) Paragraph (b)(1)(vi) of this section applies instead of 40 CFR 1065.145(b).

(vii) Vehicles other than HEVs that apply technology involving engine shutdown during 

idle may apply the sampling provisions of § 1066.501(c).

(c) The following table summarizes the requirements of paragraph (b)(2) of this section:
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TABLE 1 OF § 1066.110–SUMMARY OF EQUIPMENT SPECIFICATIONS FROM 40 CFR PART 

1065, SUBPART B, THAT APPLY FOR CHASSIS TESTING

40 CFR part 1065 

references Applicability for chassis testing under this part

40 CFR 1065.140

Use all except as noted:

40 CFR 1065.140(b) applies as described in this section.

Use 40 CFR 1065.140(c)(6), with the additional 

allowance described in this section.

Do not use 40 CFR 1065.140(d)(2)(iv). 

Use 40 CFR 1065.140(e)(1) as described in this section. 

Do not use 40 CFR 1065.140(e)(2).

40 CFR 1065.145 Use all except 40 CFR 1065.145(b).

40 CFR 1065.150 

through 1065.190 Use all.

§ 1066.120 Measurement instruments.

The measurement instrument requirements in 40 CFR part 1065, subpart C, apply with 

the following exceptions:

(a) The provisions of § 1066.125 apply instead of 40 CFR 1065.202.

(b) The provisions of 40 CFR 1065.210 and 1065.295 do not apply.
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§ 1066.125 Data updating, recording, and control.

This section specifies criteria that your test system must meet for updating and recording 

data. It also specifies criteria for controlling the systems related to driver demand, the 

dynamometer, sampling equipment, and measurement instruments.

(a) Read and record values and calculate mean values relative to a specified frequency as 

follows:

(1) This paragraph (a)(1) applies where we specify a minimum command and control 

frequency that is greater than the minimum recording frequency, such as for sample flow 

rates from a CVS that does not have a heat exchanger. For these measurements, the rate 

at which you read and interpret the signal must be at least as frequent as the minimum 

command and control frequency. You may record values at the same frequency, or you 

may record them as mean values, as long as the frequency of the mean values meets the 

minimum recording frequency. You must use all read values, either by recording them or 

using them to calculate mean values. For example, if your system reads and controls the 

sample flow rate at 10 Hz, you may record these values at 10 Hz, record them at 5 Hz by

averaging pairs of consecutive points together, or record them at 1 Hz by averaging five 

consecutive points together. 

(2) For all other measured values covered by this section, you may record the values 

instantaneously or as mean values, consistent with good engineering judgment. 

(3) You may not use rolling averages of measured values where a given measured value 

is included in more than one recorded mean value. 

(b) Use data acquisition and control systems that can command, control, and record at the 

following minimum frequencies:
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TABLE 1 OF § 1066.125–DATA RECORDING AND CONTROL MINIMUM FREQUENCIES

Applicable 

Section Measured Values

Minimum 

Command and 

Control 

Frequencya

Minimum

Recording 

Frequencyb,c

§ 1066.310

§ 1066.315 Vehicle speed — 10 Hz

§ 1066.425 Continuous concentrations of raw or dilute 

analyzers — 1 Hz

§ 1066.425

§ 1066.501 Power analyzer — 1 Hz

§ 1066.425 Bag concentrations of raw or dilute analyzers —

1 mean value 

per test interval

40 CFR 1065.545

§ 1066.425

Diluted exhaust flow rate from a CVS with a 

heat exchanger upstream of the flow

measurement

— 1 Hz

40 CFR 1065.545

§ 1066.425

Diluted exhaust flow rate from a CVS without 

a heat exchanger upstream of the flow 

measurement

5 Hz 1 Hz means

40 CFR 1065.545

§ 1066.425

Dilution air flow if actively controlled (for 

example, a partial-flow PM sampling system)d 5 Hz 1 Hz means

40 CFR 1065.545

§ 1066.425

Sample flow from a CVS that has a heat 

exchanger 1 Hz 1 Hz

40 CFR 1065.545

§ 1066.425

Sample flow from a CVS that does not have a 

heat exchanger 5 Hz 1 Hz means

§ 1066.420 Ambient temperature — 1 Hze

§ 1066.420 Ambient humidity — 1 Hze

§ 1066.420 Heated sample system temperatures, including 

PM filter face — 1 Hz

aCFVs that are not using active control are exempt from meeting this requirement due to their operating 

principle.

b

1 Hz means are data reported from the instrument at a higher frequency, but recorded as a series of 1 s 

mean values at a rate of 1 Hz.

c

For CFVs in a CVS, the minimum recording frequency is 1 Hz. For CFVs used to control sampling from a 

CFV CVS, the minimum recording frequency is not applicable.

dThis is not applicable to CVS dilution air.

eUnless specified elsewhere in this part or the standard-setting part. Note that this provision does not apply 

to soak periods where recording frequencies are not specified. For these instances, we recommend a 

recording frequency of ≥ 0.016 Hz.

§ 1066.130 Measurement instrument calibrations and verifications.

The measurement instrument calibration and verification requirements in 40 CFR part 

1065, subpart D, apply with the following exceptions:

(a) The calibration and verification provisions of 40 CFR 1065.303 do not apply for 

engine speed, torque, fuel rate, or intake air flow.

(b) The linearity verification provisions of 40 CFR 1065.307 do not apply for engine 

speed, torque, fuel rate, or intake air flow. Section 1066.135 specifies additional linearity

verification provisions that apply specifically for chassis testing.

(c) The provisions of § 1066.220 apply instead 40 CFR 1065.310.

(d) The provisions of 40 CFR 1065.320, 1065.325, and 1065.395 do not apply.
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(e) If you are measuring flow volumetrically (rather than measuring based on molar 

values), the provisions of § 1066.140 apply instead of 40 CFR 1065.340.

(f) The provisions of § 1066.150 apply instead 40 CFR 1065.350(c), 1065.355(c), 

1065.370(c), and 1065.375(c).

(g) Table 1 of this section summarizes the required and recommended calibrations and 

verifications that are unique to testing under this part and indicates when these must be 

performed. Perform other required or recommended calibrations and verifications as 

described in 40 CFR 1065.303, with the exceptions noted in this section. Table 1 

follows:

TABLE 1 OF § 1066.130–SUMMARY OF REQUIRED CALIBRATIONS AND VERIFICATIONS

Type of calibration or 

verification Minimum frequencya

40 CFR 1065.307: Linearity 

verification

The linearity verifications from 40 CFR part 1065 do not apply under this 

part for engine speed, torque, fuel rate, or intake air flow; the linearity 

verification described in § 1066.135 applies for the following 

measurements:

Dynamometer speed: See § 1066.220.

Dynamometer torque: See § 1066.220.

40 CFR 1065.310: Torque This calibration does not apply for testing under this part; see § 1066.220.

40 CFR 1065.320: Fuel 

flow This calibration does not apply for testing under this part.

40 CFR 1065.325: Intake 

flow This calibration does not apply for testing under this part.

40 CFR 1065.340: CVS 

calibration

This calibration does not apply for CVS flow meters calibrated 

volumetrically as described in § 1066.140.

40 CFR 1065.345: Vacuum 

leak

Required upon initial installation of the sampling system; recommended 

within 35 days before the start of an emissions test and after maintenance 

such as pre-filter changes.

40 CFR 1065.350(c), 

1065.355(c), 1065.370(c), 

and 1065.375(c)

These provisions do not apply for testing under this part; see § 1066.150.

40 CFR 1065.395: Inertial 

PM balance and weighing These verifications do not apply for testing under this part.

a

Perform calibrations and verifications more frequently if needed to conform to the measurement system 

manufacturer’s instructions and good engineering judgment.

§ 1066.135 Linearity verification.

This section describes requirements for linearity verification that are unique to testing 

under this part. (Note: see the definition of “linearity” in 40 CFR 1065.1001, where we 

explain that linearity means the degree to which measured values agree with respective 

reference values and that the term “linearity” is not used to refer to the shape of a 

measurement instrument's unprocessed response curve.) Perform other required or 

recommended calibrations and verifications as described in 40 CFR 1065.307, with the 

exceptions noted in this section. 

(a) For gas analyzer linearity, use one of the following options:

(1) Use instrument manufacturer recommendations and good engineering judgment to 

select at least ten reference values, yrefi, that cover the range of values that you expect 
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during testing (to prevent extrapolation beyond the verified range during emission 

testing). We recommend selecting zero as one of your reference values. For each range 

calibrated, if the deviation from a least-squares best-fit straight line is 2 % or less of the 

value at each data point, concentration values may be calculated by use of a straight-line 

curve fit for that range. If the deviation exceeds 2 % at any point, use the best-fit 

nonlinear equation that represents the data to within 2 % of each test point to determine 

concentration. If you use a gas divider to blend calibration gases, verify that the 

calibration curve produced names a calibration gas within 2 % of its certified 

concentration. Perform this verification between 15 and 50 % of the full-scale analyzer 

range.

(2) Use the linearity requirements of 40 CFR 1065.307, except for CO2 measurements 

used for determining fuel economy and GHG emissions for motor vehicles at or below 

14,000 pounds GVWR. If you choose this linearity option, you must use the provisions 

of 40 CFR 1065.672 to check for drift and make appropriate drift corrections.

(b) For dilution air, diluted exhaust, and raw exhaust sample flow, use a reference flow 

meter with a blower or pump to simulate flow rates. Use a restrictor, diverter valve, 

variable-speed blower, or variable-speed pump to control the range of flow rates. Use the 

reference meter’s response for the reference values.

(1) Reference flow meters. Because of the large range in flow requirements, we allow a 

variety of reference meters. For example, for diluted exhaust flow for a full-flow dilution 

system, we recommend a reference subsonic venturi flow meter with a restrictor valve 

and a blower to simulate flow rates. For dilution air, diluted exhaust for partial-flow 

dilution, and raw exhaust, we allow reference meters such as critical flow orifices, critical 

flow venturis, laminar flow elements, master mass flow standards, or Roots meters. 

Make sure the reference meter is calibrated and its calibration is NIST-traceable. If you 

use the difference of two flow measurements to determine a net flow rate, you may use 

one of the measurements as a reference for the other.

(2) Reference flow values. Because the reference flow is not absolutely constant, sample 

and record values of Qrefi



for 30 seconds and use the arithmetic mean of the values, Qref



, 

as the reference value. Refer to 40 CFR 1065.602 for an example of calculating an 

arithmetic mean.

(3) Linearity criteria. The values measured during linearity verification for flow meters 

must meet the following criteria: | xmin(a1-1)+a0 | ≤ 1 % ∙ Qmax



; a1 = 0.98-1.02; SEE = ≤ 2 

% ∙ Qmax



; and r

2

≥ 0.990.

(c) Perform linearity verifications for the following temperature measurements instead of 

those specified at 40 CFR 1065.307(e)(7):

(1) Test cell ambient air.

(2) Dilution air for PM sampling, including CVS, double-dilution, and partial-flow 

systems.

(3) PM sample.

(4) Chiller sample, for gaseous sampling systems that use thermal chillers to dry samples,

and that use chiller temperature to calculate dewpoint at the chiller outlet. For testing, if 

you choose to use the high alarm temperature setpoint for the chiller temperature as a 
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constant value in determining the amount of water removed from the emission sample, 

you may verify the accuracy of the high alarm temperature setpoint using good 

engineering judgment without following the linearity verification for chiller temperature. 

We recommend that you input a simulated reference temperature signal below the alarm 

setpoint, increase this signal until the high alarm trips, and verify that the alarm setpoint 

value is no less than 2 °C below the reference value at the trip point.

(5) CVS flow meter inlet temperature.

(d) Perform linearity verifications for the following pressure measurements instead of 

those specified at 40 CFR 1065.307(e)(8):

(1) Exhaust back pressure at the tailpipe exit.

(2) Barometric pressure.

(3) CVS flow meter inlet pressure.

(4) Sample dryer, for gaseous sampling systems that use either osmotic-membrane dryers 

or thermal chillers to dry samples. For your testing, if you choose to use a low alarm 

pressure setpoint for the sample dryer pressure as a constant value in determining the 

amount of water removed from the emission sample, you may verify the accuracy of the 

low alarm pressure setpoint using good engineering judgment without following the 

linearity verification for sample dryer pressure. We recommend that you input a 

reference pressure signal above the alarm setpoint, decrease this signal until the low 

alarm trips, and verify that the alarm setpoint value is no more than 4 kPa above the 

reference value at the trip point.

(e) When following procedures or practices that we incorporate by reference in § 

1066.1010, you must meet the linearity requirements given by the procedure or practice 

for any analytical instruments not covered under 40 CFR 1065.307, such as GC-FID or 

HPLC.

§ 1066.140 Diluted exhaust flow calibration.

(a) Overview. This section describes how to calibrate flow meters for diluted exhaust 

constant-volume sampling (CVS) systems. We recommend that you also use this section 

to calibrate flow meters that use a subsonic venturi or ultrasonic flow to measure raw 

exhaust flow. You may follow the molar flow calibration procedures in 40 CFR 

1065.340 instead of the procedures in this section.

(b) Scope and frequency. Perform this calibration while the flow meter is installed in its 

permanent position, except as allowed in paragraph (c) of this section. Perform this 

calibration after you change any part of the flow configuration upstream or downstream 

of the flow meter that may affect the flow-meter calibration. Perform this calibration 

upon initial CVS installation and whenever corrective action does not resolve a failure to 

meet the diluted exhaust flow verification (i.e., propane check) in 40 CFR 1065.341.

(c) Ex-situ CFV and SSV calibration. You may remove a CFV or SSV from its 

permanent position for calibration as long as the flow meter meets the requirements in 40 

CFR 1065.340(c).

(d) Reference flow meter. Calibrate each CVS flow meter using a reference flow meter 

such as a subsonic venturi flow meter, a long-radius ASME/NIST flow nozzle, a smooth 

approach orifice, a laminar flow element, or an ultrasonic flow meter. Use a reference 
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flow meter that reports quantities that are NIST-traceable within ±1 % uncertainty. Use 

this reference flow meter’s response to flow as the reference value for CVS flow-meter 

calibration.

(e) Configuration. Calibrate the system with any upstream screens or other restrictions 

that will be used during testing and that could affect the flow ahead of the reference flow 

meter. You may not use any upstream screen or other restriction that could affect the 

flow ahead of the reference flow meter, unless the flow meter has been calibrated with 

such a restriction.

(f) PDP calibration. Calibrate each positive-displacement pump (PDP) to determine a 

flow-versus-PDP speed equation that accounts for flow leakage across sealing surfaces in 

the PDP as a function of PDP inlet pressure. Determine unique equation coefficients for 

each speed at which you operate the PDP. Calibrate a PDP flow meter as follows:

(1) Connect the system as shown in Figure 1 of this section.

(2) Leaks between the calibration flow meter and the PDP must be less than 0.3 % of the 

total flow at the lowest calibrated flow point; for example, at the highest restriction and 

lowest PDP-speed point. 

(3) While the PDP operates, maintain a constant temperature at the PDP inlet within ±2 

% of the mean absolute inlet temperature, Tin .

(4) Set the PDP speed to the first speed point at which you intend to calibrate.

(5) Set the variable restrictor to its wide-open position.

(6) Operate the PDP for at least 3 min to stabilize the system. Continue operating the 

PDP and record the mean values of at least 30 seconds of sampled data of each of the 

following quantities:

(i) The mean flow rate of the reference flow meter, Qref



. This may include several 

measurements of different quantities, such as reference meter pressures and temperatures, 

for calculating Qref



.

(ii) The mean temperature at the PDP inlet, Tin .

(iii) The mean static absolute pressure at the PDP inlet, in p .

(iv) The mean static absolute pressure at the PDP outlet, out p .

(v) The mean PDP speed, nPDP f .

(7) Incrementally close the restrictor valve to decrease the absolute pressure at the inlet to 

the PDP, in p .

(8) Repeat the steps in paragraphs (f)(6) and (7) of this section to record data at a 

minimum of six restrictor positions ranging from the wide-open restrictor position to the 

minimum expected pressure at the PDP inlet.

(9) Calibrate the PDP by using the collected data and the equations in § 1066.625(a).

(10) Repeat the steps in paragraphs (f)(6) through (9) of this section for each speed at 

which you operate the PDP.

(11) Use the equations in § 1066.630(a) to determine the PDP flow equation for emission 

testing.
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(12) Verify the calibration by performing a CVS verification (i.e., propane check) as 

described in 40 CFR 1065.341.

(13) Ensure that the lowest inlet pressure tested during calibration is at least as low as the 

lowest PDP inlet pressure that will occur during emission testing. You may not use the 

PDP below the lowest inlet pressure tested during calibration.

(g) SSV calibration. Calibrate each subsonic venturi (SSV) to determine its discharge 

coefficient, Cd, for the expected range of inlet pressures. Calibrate an SSV flow meter as 

follows:

(1) Configure your calibration system as shown in Figure 1 of this section.

(2) Verify that any leaks between the calibration flow meter and the SSV are less than 0.3 

% of the total flow at the highest restriction.

(3) Start the blower downstream of the SSV.

(4) While the SSV operates, maintain a constant temperature at the SSV inlet within ±2 

% of the mean absolute inlet temperature, Tin .

(5) Set the variable restrictor or variable-speed blower to a flow rate greater than the 

greatest flow rate expected during testing. You may not extrapolate flow rates beyond 

calibrated values, so we recommend that you make sure the Reynolds number, Re#, at the 

SSV throat at the greatest calibrated flow rate is greater than the maximum Re#expected 

during testing.

(6) Operate the SSV for at least 3 min to stabilize the system. Continue operating the 

SSV and record the mean of at least 30 seconds of sampled data of each of the following 

quantities:

(i) The mean flow rate of the reference flow meter, Qref



. This may include several 

measurements of different quantities for calculating Qref



, such as reference meter 

pressures and temperatures.

(ii) The mean temperature at the venturi inlet, Tin .

(iii) The mean static absolute pressure at the venturi inlet, in p .

(iv) Mean static differential pressure between the static pressure at the venturi inlet and 

the static pressure at the venturi throat, SSV p .

(7) Incrementally close the restrictor valve or decrease the blower speed to decrease the 

flow rate.

(8) Repeat the steps in paragraphs (g)(6) and (7) of this section to record data at a 

minimum of ten flow rates.

(9) Determine an equation to quantify Cd as a function of Re#by using the collected data 

and the equations in § 1066.625(b). Section 1066.625 also includes statistical criteria for 

validating the Cd versus Re#equation.

(10) Verify the calibration by performing a CVS verification (i.e., propane check) as 

described in 40 CFR 1065.341 using the new Cd versus Re#equation.

(11) Use the SSV only between the minimum and maximum calibrated flow rates. If you 

want to use the SSV at a higher or lower flow rate, you must recalibrate the SSV.

(12) Use the equations in § 1066.630(b) to determine SSV flow during a test.
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(h) CFV calibration. The calibration procedure described in this paragraph (h) 

establishes the value of the calibration coefficient, Kv, at measured values of pressure, 

temperature and air flow. Calibrate the CFV at the lowest expected static differential 

pressure between the CFV inlet and outlet. Calibrate the CFV as follows:

(1) Configure your calibration system as shown in Figure 1 of this section.

(2) Verify that any leaks between the calibration flow meter and the CFV are less than 

0.3 % of the total flow at the highest restriction.

(3) Start the blower downstream of the CFV.

(4) While the CFV operates, maintain a constant temperature at the CFV inlet within ±2 

% of the mean absolute inlet temperature, Tin .

(5) Set the variable restrictor to its wide-open position. Instead of a variable restrictor, 

you may alternately vary the pressure downstream of the CFV by varying blower speed 

or by introducing a controlled leak. Note that some blowers have limitations on 

nonloaded conditions.

(6) Operate the CFV for at least 3 min to stabilize the system. Continue operating the 

CFV and record the mean values of at least 30 seconds of sampled data of each of the 

following quantities:

(i) The mean flow rate of the reference flow meter, Qref



. This may include several 

measurements of different quantities, such as reference meter pressures and temperatures, 

for calculating Qref



.

(ii) The mean temperature at the venturi inlet, Tin .

(iii) The mean static absolute pressure at the venturi inlet, in p .

(iv) The mean static differential pressure between the CFV inlet and the CFV outlet, 

CFV p .

(7) Incrementally close the restrictor valve or decrease the downstream pressure to 

decrease the differential pressure across the CFV, CFV p .

(8) Repeat the steps in paragraphs (h)(6) and (7) of this section to record mean data at a 

minimum of ten restrictor positions, such that you test the fullest practical range of 

CFV p expected during testing. We do not require that you remove calibration 

components or CVS components to calibrate at the lowest possible restriction.

(9) Determine Kv and the lowest allowable pressure ratio, r, according to § 1066.625.

(10) Use Kv to determine CFV flow during an emission test. Do not use the CFV below 

the lowest allowed r, as determined in § 1066.625.

(11) Verify the calibration by performing a CVS verification (i.e., propane check) as 

described in 40 CFR 1065.341.

(12) If your CVS is configured to operate multiple CFVs in parallel, calibrate your CVS 

using one of the following methods:

(i) Calibrate every combination of CFVs according to this section and § 1066.625(c). 

Refer to § 1065.652(c) for instructions on calculating flow rates for this option.

(ii) Calibrate each CFV according to this section and § 1066.625. Refer to § 1066.630 

for instructions on calculating flow rates for this option.
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(i) [Reserved]

(j) Ultrasonic flow meter calibration. [Reserved]
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Figure 1 of 1066.140—CVS calibration configurations

reference

flow meter PDP

variable

restrictor

12

6

ref n

atmos p

in p out p Tin

PDP

f

t

reference

flow meter PDP

variable

restrictor

12

6

ref n

atmos p

in p out p Tin

PDP

f

t

reference

flow meter PDP

variable

restrictor

12

6

ref n

atmos p

in p out p Tin

PDP

f

t

reference SSV

flow meter

ref n

atmos p

in p Tin

Tdew

p

variable speed

blower

reference SSV

flow meter

ref n

atmos p

in p Tin

Tdew

p

variable speed

blower

reference CFV

flow meter

variable

restrictor

ref n

in p Tin

atmos p Tdew

blower

downstream

pressure

control

reference CFV

flow meter

variable

restrictor

ref n

in p Tin

atmos p Tdew

blower

downstream

pressure

control

§ 1066.145 Test fuel, engine fluids, analytical gases, and other calibration standards.

(a) Test fuel. Use test fuel as specified in the standard-setting part, or as specified in 40 

CFR part 1065, subpart H, if it is not specified in the standard-setting part.
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(b) Lubricating oil. Use lubricating oil as specified in 40 CFR 1065.740. For two-stroke 

engines that involve a specified mixture of fuel and lubricating oil, mix the lubricating oil 

with the fuel according to the manufacturer’s specifications.

(c) Coolant. For liquid-cooled engines, use coolant as specified in 40 CFR 1065.745.

(d) Analytical gases. Use analytical gases that meet the requirements of 40 CFR 

1065.750.

(e) Mass standards. Use mass standards that meet the requirements of 40 CFR 1065.790.

§ 1066.150 Analyzer interference and quench verification limit.

Analyzers must meet the interference and quench verification limits in the following table 

on the lowest, or most representative, instrument range that will be used during emission 

testing, instead of those specified in 40 CFR part 1065, subpart D:

TABLE 1 OF § 1066.150–ANALYZER INTERFERENCE AND QUENCH VERIFICATION LIMITS

Verification Limit

40 CFR 1065.350 ±2 % of full scale

40 CFR 1065.355 ±2 % of full scale

40 CFR 1065.370 ±2 % of full scale

40 CFR 1065.375 ±2 % of the flow-weighted mean concentration of 

N2O expected at the standard

Subpart C—DYNAMOMETER SPECIFICATIONS

§ 1066.201 Dynamometer overview.

This subpart addresses chassis dynamometers and related equipment.

§ 1066.210 Dynamometers.

(a) General requirements. A chassis dynamometer typically uses electrically generated 

load forces combined with its rotational inertia to recreate the mechanical inertia and 

frictional forces that a vehicle exerts on road surfaces (known as “road load”). Load 

forces are calculated using vehicle-specific coefficients and response characteristics. The 

load forces are applied to the vehicle tires by rolls connected to motor/absorbers. The 

dynamometer uses a load cell to measure the forces the dynamometer rolls apply to the 

vehicle’s tires.

(b) Accuracy and precision. The dynamometer’s output values for road load must be 

NIST-traceable. We may determine traceability to a specific national or international 

standards organization to be sufficient to demonstrate NIST-traceability. The forcemeasurement system must be capable of indicating force readings as follows:

(1) For dynamometer testing of vehicles at or below 20,000 pounds GVWR, the 

dynamometer force-measurement system must be capable of indicating force readings 

during a test to a resolution of ±0.05 % of the maximum load-cell force simulated by the 

dynamometer or ±9.8 N (±2.2 lbf), whichever is greater.

(2) For dynamometer testing of vehicles above 20,000 pounds GVWR, the forcemeasurement system must be capable of indicating force readings during a test to a 

resolution of ±0.05 % of the maximum load-cell force simulated by the dynamometer or 

±39.2 N (±8.8 lbf), whichever is greater.
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(c) Test cycles. The dynamometer must be capable of fully simulating vehicle 

performance over applicable test cycles for the vehicles being tested as referenced in the 

corresponding standard-setting part, including operation at the combination of inertial 

and road-load forces corresponding to maximum road-load conditions and maximum 

simulated inertia at the highest acceleration rate experienced during testing.

(d) Component requirements. The following specifications apply:

(1) The nominal roll diameter must be 120 cm or greater. The dynamometer must have 

an independent drive roll for each drive axle as tested under § 1066.410(g), except that 

two drive axles may share a single drive roll. Use good engineering judgment to ensure 

that the dynamometer roll diameter is large enough to provide sufficient tire-roll contact 

area to avoid tire overheating and power losses from tire-roll slippage.

(2) Measure and record force and speed at 10 Hz or faster. You may convert measured 

values to 1-Hz, 2-Hz, or 5-Hz values before your calculations, using good engineering 

judgment.

(3) The load applied by the dynamometer simulates forces acting on the vehicle during 

normal driving according to the following equation:

2 i i-1

i i i

i i-1

v v FR A B v C v M

t t



    



Eq. 1066.210-1

Where:

FR = total road-load force to be applied at the surface of the roll. The total force is the 

sum of the individual tractive forces applied at each roll surface.

i = a counter to indicate a point in time over the driving schedule. For a dynamometer 

operating at 10-Hz intervals over a 600-second driving schedule, the maximum value of i

should be 6,000.

A = a vehicle-specific constant value representing the vehicle’s frictional load in lbf or 

newtons. See subpart D of this part.

B = a vehicle-specific coefficient representing load from drag and rolling resistance, 

which are a function of vehicle speed, in lbf/mph or N∙s/m. See subpart D of this part.

v = linear speed at the roll surfaces as measured by the dynamometer, in mph or m/s. Let 

vi-1 = 0 for i = 0.

C = a vehicle-specific coefficient representing aerodynamic effects, which are a function 

of vehicle speed squared, in lbf/mph2or N∙s

2

/m2. See subpart D of this part.

M = mass of the vehicle in lbm or kg based on its test weight, including the effect of 

rotating axles as specified in § 1066.310(b)(7), divided by the acceleration due to gravity

as specified in 40 CFR 1065.630. 

t = elapsed time in the driving schedule as measured by the dynamometer, in seconds. 

Let ti-1 = 0 for i = 0.

(4) We recommend that a dynamometer capable of testing vehicles at or below 20,000 

pounds GVWR be designed to apply an actual road-load force within ±1 % or ±9.8 N 

(±2.2 lbf) of the reference value, whichever is greater. Note that slightly higher errors 
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may be expected during highly transient operation for vehicles above 8,500 pounds 

GVWR.

(e) Dynamometer manufacturer instructions. This part specifies that you follow the 

dynamometer manufacturer’s recommended procedures for things such as calibrations 

and general operation. If you perform testing with a dynamometer that you manufactured 

or if you otherwise do not have these recommended procedures, use good engineering 

judgment to establish the additional procedures and specifications we specify in this part, 

unless we specify otherwise. Keep records to describe these recommended procedures 

and how they are consistent with good engineering judgment, including any quantified 

error estimates.

§ 1066.215 Summary of verification procedures for chassis dynamometers.

(a) Overview. This section describes the overall process for verifying and calibrating the 

performance of chassis dynamometers.

(b) Scope and frequency. The following table summarizes the required and 

recommended calibrations and verifications described in this subpart and indicates when 

they must occur:

TABLE 1 OF § 1066.215–SUMMARY OF REQUIRED DYNAMOMETER VERIFICATIONS

Type of verification Minimum frequencya

§ 1066.220: Linearity verification

Speed: Upon initial installation, within 370 days before testing, and 

after major maintenance.

Torque (load): Upon initial installation and after major maintenance.

§ 1066.225: Roll runout and 

diameter verification Upon initial installation and after major maintenance.

§ 1066.230: Time verification Upon initial installation and after major maintenance.

§ 1066.235: Speed measurement 

verification

Upon initial installation, within 370 days before testing, and after 

major maintenance.

§ 1066.240: Torque (load) 

transducer verification

Upon initial installation, within 7 days of testing, and after major 

maintenance.

§ 1066.245: Response time 

verification

Upon initial installation, within 370 days before testing, and after 

major maintenance.

§ 1066.250: Base inertia 

verification Upon initial installation and after major maintenance.

§ 1066.255: Parasitic loss 

verification

Upon initial installation, after major maintenance, and upon failure of 

a verification in § 1066.270 or § 1066.275.

§ 1066.260: Parasitic friction 

compensation verification

Upon initial installation, after major maintenance, and upon failure of 

a verification in § 1066.270 or § 1066.275.

§ 1066.265: Acceleration and 

deceleration verification Upon initial installation and after major maintenance.

§ 1066.270: Unloaded coastdown 

verification

Upon initial installation, within 7 days of testing, and after major 

maintenance.

§ 1066.275 Dynamometer 

readiness verification

Upon initial installation, within 1 day before testing, and after major 

maintenance.

a

Perform calibrations and verifications more frequently, according to measurement system manufacturer 

instructions and good engineering judgment.
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(c) Automated dynamometer verifications and calibrations. In some cases, 

dynamometers are designed with internal diagnostic and control features to accomplish 

the verifications and calibrations specified in this subpart. You may use these automated 

functions instead of following the procedures we specify in this subpart to demonstrate 

compliance with applicable requirements, consistent with good engineering judgment. 

(d) Sequence of verifications and calibrations. Upon initial installation and after major 

maintenance, perform the verifications and calibrations in the same sequence as noted in 

Table 1 of this section, except that you may perform speed linearity verification after the 

verifications in §§ 1066.225 and 1066.230. At other times, you may need to perform 

specific verifications or calibrations in a certain sequence, as noted in this subpart. If you 

perform major maintenance on a specific component, you are required to perform 

verifications and calibrations only on components or parameters that are affected by the 

maintenance.

(e) Corrections. Unless the regulation directs otherwise, if the dynamometer fails to meet 

any specified calibration or verification, make any necessary adjustments or repairs such 

that the dynamometer meets the specification before running a test. Repairs required to 

meet specifications are generally considered major maintenance under this part.

§ 1066.220 Linearity verification for chassis dynamometer systems.

(a) Scope and frequency. Perform linearity verification for dynamometer speed and 

torque at least as frequently as indicated in Table 1 of § 1066.215. The intent of linearity 

verification is to determine that the system responds accurately and proportionally over 

the measurement range of interest. Linearity verification generally consists of 

introducing a series of at least 10 reference values to a measurement system. The 

measurement system quantifies each reference value. The measured values are then 

collectively compared to the reference values by using a least-squares linear regression 

and the linearity criteria specified in Table 1 of this section.

(b) Performance requirements. If a measurement system does not meet the applicable 

linearity criteria in Table 1 of this section, correct the deficiency by re-calibrating, 

servicing, or replacing components as needed. Repeat the linearity verification after 

correcting the deficiency to ensure that the measurement system meets the linearity

criteria. Before you may use a measurement system that does not meet linearity criteria, 

you must demonstrate to us that the deficiency does not adversely affect your ability to 

demonstrate compliance with the applicable standards.

(c) Procedure. Use the following linearity verification protocol, or use good engineering 

judgment to develop a different protocol that satisfies the intent of this section, as 

described in paragraph (a) of this section:

(1) In this paragraph (c), the letter “y” denotes a generic measured quantity, the 

superscript over-bar denotes an arithmetic mean (such as y ), and the subscript “ref” 

denotes the known or reference quantity being measured.

(2) Operate the dynamometer system at the specified operating conditions. This may

include any specified adjustment or periodic calibration of the dynamometer system.

(3) Set dynamometer speed and torque to zero.
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(4) Verify the dynamometer speed or torque signal based on the dynamometer 

manufacturer’s recommendations. 

(5) After verification, check for zero speed and torque. Use good engineering judgment 

to determine whether or not to rezero or re-verify speed and torque before continuing. 

(6) For both speed and torque, use the dynamometer manufacturer’s recommendations 

and good engineering judgment to select reference values, yrefi, that cover a range of 

values that you expect would prevent extrapolation beyond these values during emission 

testing. We recommend selecting zero speed and zero torque as reference values for the 

linearity verification.

(7) Use the dynamometer manufacturer’s recommendations and good engineering 

judgment to select the order in which you will introduce the series of reference values. 

For example, you may select the reference values randomly to avoid correlation with 

previous measurements and to avoid the influence of hysteresis; you may select reference 

values in ascending or descending order to avoid long settling times of reference signals; 

or you may select values to ascend and then descend to incorporate the effects of any

instrument hysteresis into the linearity verification.

(8) Set the dynamometer to operate at a reference condition. 

(9) Allow time for the dynamometer to stabilize while it measures the reference values.

(10) At a recording frequency of at least 1 Hz, measure speed and torque values for 30 

seconds and record the arithmetic mean of the recorded values, i

y . Refer to 40 CFR 

1065.602 for an example of calculating an arithmetic mean.

(11) Repeat the steps in paragraphs (c)(8) though (10) of this section until you measure 

speeds and torques at each of the reference settings.

(12) Use the arithmetic means, i

y , and reference values, yrefi , to calculate least-squares 

linear regression parameters and statistical values to compare to the minimum 

performance criteria specified in Table 1 of this section. Use the calculations described 

in 40 CFR 1065.602. Using good engineering judgment, you may weight the results of 

individual data pairs (i.e., (yrefi, i

y )), in the linear regression calculations. Table 1

follows:

TABLE 1 OF § 1066.220–

DYNAMOMETER MEASUREMENT SYSTEMS THAT REQUIRE LINEARITY VERIFICATIONS

Measurement 

system Quantity Linearity criteria

| ymin∙(a1-1)+a0| a1 SEE r

2

Speed v <0.05 % ∙ max v 0.98-1.02 <2 % ∙ max v >0.990

Torque (load) T <1 % ∙ Tmax 0.99-1.01 <1 % ∙ Tmax >0.990

(d) Reference signals. Generate reference values for the linearity-verification protocol in 

paragraph (c) of this section as described for speed and torque in 40 CFR 1065.307(d). 

§ 1066.225 Roll runout and diameter verification procedure.

(a) Overview. This section describes the verification procedure for roll runout and roll 

diameter. Roll runout is a measure of the variation in roll radius around the 

circumference of the roll.
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(b) Scope and frequency. Perform these verifications upon initial installation and after 

major maintenance that could affect roll surface finish or dimensions (such as resurfacing 

or polishing).

(c) Roll runout procedure. Verify roll runout based on the following procedure, or an 

equivalent procedure based on good engineering judgment:

(1) Perform this verification with laboratory and dynamometer temperatures stable and at 

equilibrium. Release the roll brake and shut off power to the dynamometer. Remove any 

dirt, rubber, rust, and debris from the roll surface. Mark measurement locations on the 

roll surface using a marker. Mark the roll at a minimum of four equally spaced locations 

across the roll width; we recommend taking measurements every 150 mm across the roll. 

Secure the marker to the deck plate adjacent to the roll surface and slowly rotate the roll 

to mark a clear line around the roll circumference. Repeat this process for all 

measurement locations.

(2) Measure roll runout using an indicator with a probe that allows for measuring the 

position of the roll surface relative to the roll centerline as it turns through a complete 

revolution. The indicator must have some means of being securely mounted adjacent to 

the roll. The indicator must have sufficient range to measure roll runout at all points, 

with a minimum accuracy of ±0.025 mm. Calibrate the indicator according to the 

instrument manufacturer’s instructions.

(3) Position the indicator adjacent to the roll surface at the desired measurement location. 

Position the shaft of the indicator perpendicular to the roll such that the point of the 

indicator is slightly touching the surface of the roll and can move freely through a full 

rotation of the roll. Zero the indicator according to the instrument manufacturer’s 

instructions. Avoid distortion of the runout measurement from the weight of a person 

standing on or near the mounted dial indicator.

(4) Slowly turn the roll through a complete rotation and record the maximum and 

minimum values from the indicator. Calculate runout as the difference between these 

maximum and minimum values. 

(5) Repeat the steps in paragraphs (c)(3) and (4) of this section for all measurement 

locations.

(6) The roll runout must be less than 0.254 mm (0.0100 inches) at all measurement 

locations.

(d) Diameter procedure. Verify roll diameter based on the following procedure, or an 

equivalent procedure based on good engineering judgment: 

(1) Prepare the laboratory and the dynamometer as specified in paragraph (c)(1) of this 

section. 

(2) Measure roll diameter using a Pi Tape®. Orient the Pi Tape®to the marker line at the 

desired measurement location with the Pi Tape®hook pointed outward. Temporarily

secure the Pi Tape®to the roll near the hook end with adhesive tape. Slowly turn the roll, 

wrapping the Pi Tape®around the roll surface. Ensure that the Pi Tape®is flat and 

adjacent to the marker line around the full circumference of the roll. Attach a 2.26-kg 

weight to the hook of the Pi Tape®and position the roll so that the weight dangles freely. 

Remove the adhesive tape without disturbing the orientation or alignment of the Pi 

Tape®.
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(3) Overlap the gage member and the vernier scale ends of the Pi Tape®to read the 

diameter measurement to the nearest 0.01 mm. Follow the manufacturer’s 

recommendation to correct the measurement to 20 °C, if applicable. 

(4) Repeat the steps in paragraphs (d)(2) and (3) of this section for all measurement 

locations.

(5) The measured roll diameter must be within ±0.254 mm of the specified nominal value 

at all measurement locations. You may revise the nominal value to meet this 

specification, as long as you use the corrected nominal value for all calculations in this 

subpart. 

§ 1066.230 Time verification procedure.

(a) Overview. This section describes how to verify the accuracy of the dynamometer’s 

timing device.

(b) Scope and frequency. Perform this verification upon initial installation and after 

major maintenance.

(c) Procedure. Perform this verification using one of the following procedures:

(1) WWV method. You may use the time and frequency signal broadcast by NIST from 

radio station WWV as the time standard if the trigger for the dynamometer timing circuit 

has a frequency decoder circuit, as follows:

(i) Contact station WWV by telephone by dialing (303) 499-7111 and listen for the time 

announcement. Verify that the trigger started the dynamometer timer. Use good 

engineering judgment to minimize error in receiving the time and frequency signal.

(ii) After at least 1000 seconds, re-dial station WWV and listen for the time 

announcement. Verify that the trigger stopped the dynamometer timer.

(iii) Compare the measured elapsed time, yact, to the corresponding time standard, yref, to 

determine the time error, yerror, using the following equation:

act ref

error

ref

100 %

y y

y

y



 

Eq. 1066.230-1

(2) Ramping method. You may use an operator-defined ramp function to serve as the 

time standard as follows:

(i) Set up a signal generator to output a marker voltage at the peak of each ramp to trigger 

the dynamometer timing circuit. Output the designated marker voltage to start the 

verification period.

(ii) After at least 1000 seconds, output the designated marker voltage to end the 

verification period.

(iii) Compare the measured elapsed time between marker signals, yact, to the 

corresponding time standard, yref, to determine the time error, yerror, using Eq. 1066.230-1.

(3) Dynamometer coastdown method. You may use a signal generator to output a known 

speed ramp signal to the dynamometer controller to serve as the time standard as follows:

(i) Generate upper and lower speed values to trigger the start and stop functions of the 

coastdown timer circuit. Use the signal generator to start the verification period. 

(ii) After at least 1000 seconds, use the signal generator to end the verification period. 
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(iii) Compare the measured elapsed time between trigger signals, yact, to the 

corresponding time standard, yref, to determine the time error, yerror, using Eq. 1066.230-1.

(d) Performance evaluation. The time error determined in paragraph (c) of this section 

may not exceed ±0.001 %. 

§ 1066.235 Speed verification procedure.

(a) Overview. This section describes how to verify the accuracy of the dynamometer 

speed determination. When performing this verification, you must also ensure the 

dynamometer speed at any devices used to display or record vehicle speed (such as a 

driver’s aid) is representative of the speed input from the dynamometer speed 

determination.

(b) Scope and frequency. Perform this verification upon initial installation, within 370 

days before testing, and after major maintenance.

(c) Procedure. Use one of the following procedures to verify the accuracy and resolution 

of the dynamometer speed simulation:

(1) Pulse method. Connect a universal frequency counter to the output of the 

dynamometer’s speed-sensing device in parallel with the signal to the dynamometer 

controller. The universal frequency counter must be calibrated according to the counter 

manufacturer’s instructions and be capable of measuring with enough accuracy to 

perform the procedure as specified in this paragraph (c)(1). Make sure the 

instrumentation does not affect the signal to the dynamometer control circuits. 

Determine the speed error as follows:

(i) Set the dynamometer to speed-control mode. Set the dynamometer speed to a value of 

approximately 4.5 m/s (10 mph); record the output of the frequency counter after 10 

seconds. Determine the roll speed, vact, using the following equation:

roll

act

f d

v

n

 



Eq. 1066.235-1

Where:

f = frequency of the dynamometer speed sensing device, accurate to at least four 

significant figures.

droll = nominal roll diameter, accurate to the nearest 1.0 mm, consistent with § 

1066.225(d).

n = the number of pulses per revolution from the dynamometer roll speed sensor.

Example:

f = 2.9231 Hz = 2.9231 s-1

droll = 904.40 mm = 0.90440 m

n = 1 pulse/rev

act

2.9231 0.90440

1

v

 



vact = 8.3053 m/s
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(ii) Repeat the steps in paragraph (c)(1)(i) of this section for the maximum speed 

expected during testing and at least two additional evenly spaced speed points between 

the starting speed and the maximum speed point.

(iii) Compare the calculated roll speed, vact, to each corresponding speed set point, vref, to 

determine values for speed error at each set point, verror, using the following equation:

verror = vact - vref

Eq. 1066.235-2

Example:

vact = 8.3053 m/s

vref = 8.3000 m/s

verror = 8.3053 – 8.3000 = 0.0053 m/s

(2) Frequency method. Install a piece of tape in the shape of an arrowhead on the surface 

of the dynamometer roll near the outer edge. Put a reference mark on the deck plate in 

line with the tape. Install a stroboscope or photo tachometer on the deck plate and direct 

the flash toward the tape on the roll. The stroboscope or photo tachometer must be 

calibrated according to the instrument manufacturer’s instructions and be capable of 

measuring with enough accuracy to perform the procedure as specified in this paragraph 

(c)(2). Determine the speed error as follows:

(i) Set the dynamometer to speed-control mode. Set the dynamometer speed to a speed 

value of approximately 4.5 m/s (10 mph). Tune the stroboscope or photo tachometer 

until the signal matches the dynamometer roll speed. Record the frequency. Determine 

the roll speed, yact, using Eq. 1066.235-1, using the stroboscope or photo tachometer’s 

frequency for f.

(ii) Repeat the steps in paragraph (c)(2)(i) of this section for the maximum speed 

expected during testing and at least two additional evenly spaced speed points between 

the starting speed and the maximum speed point.

(iii) Compare the calculated roll speed, vact, to each corresponding speed set point, vref, to 

determine values for speed error at each set point, yerror, using Eq. 1066.235-2.

(d) Performance evaluation. The speed error determined in paragraph (c) of this section 

may not exceed ±0.02 m/s at any speed set point. 

§ 1066.240 Torque transducer verification.

Verify torque-measurement systems by performing the verifications described in §§ 

1066.270 and 1066.275.

§ 1066.245 Response time verification.

(a) Overview. This section describes how to verify the dynamometer’s response time to a 

step change in tractive force.

(b) Scope and frequency. Perform this verification upon initial installation, within 370 

days before testing (i.e., annually), and after major maintenance.

(c) Procedure. Use the dynamometer’s automated process to verify response time. You 

may perform this test either at two different inertia settings corresponding approximately
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to the minimum and maximum vehicle weights you expect to test or using base inertia 

and two acceleration rates that cover the range of acceleration rates experienced during 

testing (such as 0.5 and 8 mph/s). Use good engineering judgment to select road-load 

coefficients representing vehicles of the appropriate weight. Determine the 

dynamometer’s settling response time, ts, based on the point at which there are no 

measured results more than 10 % above or below the final equilibrium value, as 

illustrated in Figure 1 of this section. The observed settling response time must be less 

than 100 milliseconds for each inertia setting. 
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Figure 1 of § 1066.245—Example of a settling response time diagram

Time (t)

ts

Response

1.1

1.0

0.9

§ 1066.250 Base inertia verification.

(a) Overview. This section describes how to verify the dynamometer’s base inertia.

(b) Scope and frequency. Perform this verification upon initial installation and after 

major maintenance, such as maintenance that could affect roll inertia. 

(c) Procedure. Verify the base inertia using the following procedure:

(1) Warm up the dynamometer according to the dynamometer manufacturer’s 

instructions. Set the dynamometer’s road-load inertia to zero, turning off any electrical 

simulation of road load and inertia so that the base inertia of the dynamometer is the only 

inertia present. Motor the rolls to 5 mph. Apply a constant force to accelerate the roll at 

a nominal rate of 1 mph/s. Measure the elapsed time to accelerate from 10 to 40 mph, 

noting the corresponding speed and time points to the nearest 0.01 mph and 0.01 s. Also 

determine average force over the measurement interval.

(2) Starting from a steady roll speed of 45 mph, apply a constant force to the roll to 

decelerate the roll at a nominal rate of 1 mph/s. Measure the elapsed time to decelerate 

from 40 to 10 mph, noting the corresponding speed and time points to the nearest 0.01 

mph and 0.01 s. Also determine average force over the measurement interval.

(3) Repeat the steps in paragraphs (c)(1) and (2) of this section for a total of five sets of 

results at the nominal acceleration rate and the nominal deceleration rate.

(4) Use good engineering judgment to select two additional acceleration and deceleration 

rate pairs that cover the middle and upper rates expected during testing. Repeat the steps 

in paragraphs (c)(1) through (3) of this section at each of these additional acceleration 

and deceleration rates.

(5) Determine the base inertia, Ib, for each measurement interval using the following 

equation:
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b

final init

F

I

v v

t







Eq. 1066.250-1

Where:

F = average dynamometer force over the measurement interval as measured by the 

dynamometer.

vfinal = roll surface speed at the end of the measurement interval to the nearest 0.01 mph.

vinit = roll surface speed at the start of the measurement interval to the nearest 0.01 mph.

t = elapsed time during the measurement interval to the nearest 0.01 s.

Example:

F = 1.500 lbf = 48.26 ft∙lbm/s2

vfinal = 40.00 mph = 58.67 ft/s

vinit = 10.00 mph = 14.67 ft/s

t = 30.00 s

b

48.26

58.67 14.67

30.00

I 



Ib = 32.90 lbm

(6) Calculate the base inertia error, Iberror, for each of the thirty measured base inertia 

values, Ib, by comparing it to the manufacturer’s stated base inertia, Ibref, using the 

following equation:

bref bact

berror

bref

100 % I I I

I



 

Eq. 1066.250-2

Example:

Ibref = 32.96 lbm

bact I = 32.90 lbm (from paragraph (c)(5) of this section)

berror

32.96 32.90 100 %

32.96

I



 

Iberror = 0.18 %

(7) Determine the base inertia mean value, b

I , from the ten acceleration and deceleration 

interval base inertia values for each of the three acceleration/deceleration rates. Then 

determine the base inertia mean value, b

I , from the base inertia values corresponding to 
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acceleration/deceleration rates. Calculate base inertia mean values as described in 40 

CFR 1065.602(b)

(8) Calculate the inertia error for the final base inertia mean value from paragraph (c)(7) 

of this section. Use Eq. 1066.250-2, substituting the final base inertia mean value from 

paragraph (c)(7) of this section for the individual base inertia.

(d) Performance evaluation. The dynamometer must meet the following specifications to 

be used for testing under this part:

(1) All base inertia errors determined under paragraph (c)(6) of this section may not 

exceed ±1.0 %. 

(2) The inertia error for the final base inertia mean value determined under paragraph 

(c)(8) of this section may not exceed ±0.20 %. 

§ 1066.255 Parasitic loss verification.

(a) Overview. Verify the dynamometer’s parasitic loss as described in this section, and 

correct as necessary. This procedure determines the dynamometer’s internal losses that it 

must overcome to simulate road load. Characterize these losses in a parasitic loss curve 

that the dynamometer uses to apply compensating forces to maintain the desired roadload force at the roll surface.

(b) Scope and frequency. Perform this verification upon initial installation, after major 

maintenance, and upon failure of a verification in either § 1066.270 or § 1066.275. 

(c) Procedure. Perform this verification by following the dynamometer manufacturer’s 

specifications to establish a parasitic loss curve, taking data at fixed speed intervals to 

cover the range of vehicle speeds that will occur during testing. You may zero the load 

cell at a selected speed if that improves your ability to determine the parasitic loss. 

Parasitic loss forces may never be negative. Note that the torque transducers must be 

zeroed and spanned prior to performing this procedure.

(d) Performance evaluation. Some dynamometers automatically update the parasitic loss 

curve for further testing. If this is not the case, compare the new parasitic loss curve to 

the original parasitic loss curve from the dynamometer manufacturer or the most recent 

parasitic loss curve you programmed into the dynamometer. You may reprogram the 

dynamometer to accept the new curve in all cases, and you must reprogram the 

dynamometer if any point on the new curve departs from the earlier curve by more than 

±9.0 N for dynamometers capable of testing vehicles at or below 20,000 pounds GVWR,

or ±36.0 N (±8.0 lbf) for dynamometers not capable of testing vehicles at or below 

20,000 pounds GVWR. 

§ 1066.260 Parasitic friction compensation evaluation.

(a) Overview. This section describes how to verify the accuracy of the dynamometer’s 

friction compensation.

(b) Scope and frequency. Perform this verification upon initial installation, after major 

maintenance, and upon failure of a verification in either § 1066.270 or § 1066.275. Note 

that this procedure relies on proper verification of speed and torque, as described in §§ 

1066.235 and 1066.240. You must also first verify the dynamometer’s parasitic loss 

curve as specified in § 1066.255.
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(c) Procedure. Use the following procedure to verify the accuracy of the dynamometer’s 

friction compensation:

(1) Warm up the dynamometer as specified by the dynamometer manufacturer. 

(2) Perform a torque verification as specified by the dynamometer manufacturer. For 

torque verifications relying on shunt procedures, if the results do not conform to 

specifications, recalibrate the dynamometer using NIST-traceable standards as 

appropriate until the dynamometer passes the torque verification. Do not change the 

dynamometer’s base inertia to pass the torque verification.

(3) Set the dynamometer inertia to the base inertia with the road-load coefficients A, B, 

and C set to 0. Set the dynamometer to speed-control mode with a target speed of 50 

mph or a higher speed recommended by the dynamometer manufacturer. Once the speed 

stabilizes at the target speed, switch the dynamometer from speed-control to torquecontrol and allow the roll to coast for 60 seconds. Record the initial and final speeds and 

the corresponding start and stop times. If friction compensation is executed perfectly, 

there will be no change in speed during the measurement interval.

(4) Calculate the power equivalent of friction compensation error, FCerror, using the 

following equation:

 

2 2

error init final 2

I

FC v v

t

  



Eq. 1066.260-1

Where:

I = dynamometer inertia setting.

t = duration of the measurement interval, accurate to at least 0.01 s.

vinit = the roll speed corresponding to the start of the measurement interval, accurate to at 

least 0.05 mph.

vfinal = the roll speed corresponding to the end of the measurement interval, accurate to at 

least 0.05 mph.

Example:

I = 2000 lbm = 62.16 lbf·s2/ft

t = 60.0 s

vinit = 9.2 mph = 13.5 ft/s

vfinal = 10.0 mph = 14.7 ft/s

 

2 2

error

62.16 13.5 14.7

2 60.00

FC   



FCerror = –16.5 ft∙lbf/s = –0.031 hp

(5) The friction compensation error may not exceed ±0.15 hp for dynamometers capable 

of testing vehicles at or below 20,000 pounds GVWR, or ±0.6 hp for dynamometers not 

capable of testing vehicles at or below 20,000 pounds GVWR. 

§ 1066.265 Acceleration and deceleration verification.

(a) Overview. This section describes how to verify the dynamometer’s ability to achieve 

targeted acceleration and deceleration rates. Paragraph (c) of this section describes how 
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Page 960 of 1039

this verification applies when the dynamometer is programmed directly for a specific 

acceleration or deceleration rate. Paragraph (d) of this section describes how this 

verification applies when the dynamometer is programmed with a calculated force to 

achieve a targeted acceleration or deceleration rate.

(b) Scope and frequency. Perform this verification or an equivalent procedure upon 

initial installation and after major maintenance that could affect acceleration and 

deceleration accuracy. Note that this procedure relies on proper verification of speed as 

described in § 1066.235.

(c) Verification of acceleration and deceleration rates. Activate the dynamometer’s 

function generator for measuring roll revolution frequency. If the dynamometer has no 

such function generator, set up a properly calibrated external function generator 

consistent with the verification described in this paragraph (c). Use the function 

generator to determine actual acceleration and deceleration rates as the dynamometer 

traverses speeds between 10 and 40 mph at various nominal acceleration and deceleration 

rates. Verify the dynamometer’s acceleration and deceleration rates as follows:

(1) Set up start and stop frequencies specific to your dynamometer by identifying the rollrevolution frequency, f, in revolutions per second (or Hz) corresponding to 10 mph and 

40 mph vehicle speeds, accurate to at least four significant figures, using the following 

equation:

roll

v n f

d 







Eq. 1066.265-1

Where:

v = the target roll speed, in inches per second (corresponding to drive speeds of 10 mph 

or 40 mph).

n = the number of pulses from the dynamometer’s roll-speed sensor per roll revolution.

droll = roll diameter, in inches.

(2) Program the dynamometer to accelerate the roll at a nominal rate of 1 mph/s from 10 

mph to 40 mph. Measure the elapsed time to reach the target speed, to the nearest 0.01 s. 

Repeat this measurement for a total of five runs. Determine the actual acceleration rate 

for each run, aact, using the following equation:

final init

act

v v

a

t





Eq. 1066.265-2

Where:

aact = acceleration rate (decelerations have negative values).

vfinal = the target value for the final roll speed.

vinit = the setpoint value for the initial roll speed.

t = time to accelerate from vinit to vfinal.

Example:

vfinal = 40 mph

vinit = 10 mph
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Page 961 of 1039

t = 30.003 s

act

40.00 10.00

30.03

a





aact = 0.999 mph/s

(3) Program the dynamometer to decelerate the roll at a nominal rate of 1 mph/s from 40 

mph to 10 mph. Measure the elapsed time to reach the target speed, to the nearest 0.01 s. 

Repeat this measurement for a total of five runs. Determine the actual acceleration rate, 

aact, using Eq. 1066.265-2

(4) Repeat the steps in paragraphs (c)(2) and (3) of this section for additional acceleration 

and deceleration rates in 1 mph/s increments up to and including one increment above the 

maximum acceleration rate expected during testing. Average the five repeat runs to 

calculate a mean acceleration rate, act a , at each setting.

(5) Compare each mean acceleration rate, act a , to the corresponding nominal acceleration 

rate, aref, to determine values for acceleration error, aerror, using the following equation:

act ref

error

ref

100 % a aa

a



 

Eq. 1066.265-3

Example:

act a = 0.999 mph/s

aref = 1 mph/s

error

0.999 1

100 %

1

a



 

aerror = –0.100 %

(d) Verification of forces for controlling acceleration and deceleration. Program the 

dynamometer with a calculated force value and determine actual acceleration and 

deceleration rates as the dynamometer traverses speeds between 10 and 40 mph at 

various nominal acceleration and deceleration rates. Verify the dynamometer’s ability to 

achieve certain acceleration and deceleration rates with a given force as follows:

(1) Calculate the force setting, F, using the following equation:

FIa   b

Eq. 1066.265-4

Where:

Ib = the dynamometer manufacturer’s stated base inertia, in lbf·s2/ft.

a = nominal acceleration rate, in ft/s2.

Example:

Ib = 2967 lbm = 92.217 lbf·s2/ft

a = 1 mph/s = 1.4667 ft/s2
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F   92.217 1.4667

F = 135.25 lbf

(2) Set the dynamometer to road-load mode and program it with a calculated force to 

accelerate the roll at a nominal rate of 1 mph/s from 10 mph to 40 mph. Measure the 

elapsed time to reach the target speed, to the nearest 0.01 s. Repeat this measurement for 

a total of five runs. Determine the actual acceleration rate, aact, for each run using Eq. 

1066.265-2. Repeat this step to determine measured “negative acceleration” rates using a 

calculated force to decelerate the roll at a nominal rate of 1 mph/s from 40 mph to 10 

mph. Average the five repeat runs to calculate a mean acceleration rate, act a , at each 

setting.

(3) Repeat the steps in paragraph (d)(2) of this section for additional acceleration and 

deceleration rates as specified in paragraph (c)(4) of this section.

(4) Compare each mean acceleration rate, act a , to the corresponding nominal acceleration 

rate, aref, to determine values for acceleration error, aerror, using Eq. 1066.265-3

(e) Performance evaluation. The acceleration error from paragraphs (c)(5) and (d)(4) of 

this section may not exceed ±1.0 %.

§ 1066.270 Unloaded coastdown verification.

(a) Overview. Use force measurements to verify the dynamometer’s settings based on 

coastdown procedures.

(b) Scope and frequency. Perform this verification upon initial installation, within 7 days 

of testing, and after major maintenance.

(c) Procedure. This procedure verifies the dynamometer’s settings derived from 

coastdown testing. For dynamometers that have an automated process for this procedure, 

perform this evaluation by setting the initial speed, final speed, inertial coefficients, and 

road-load coefficients as required for each test, using good engineering judgment to 

ensure that these values properly represent in-use operation. Use the following procedure 

if your dynamometer does not perform this verification with an automated process:

(1) Warm up the dynamometer as specified by the dynamometer manufacturer.

(2) With the dynamometer in coastdown mode, set the dynamometer inertia for the 

smallest vehicle weight that you expect to test and set A, B, and C road-load coefficients 

to values typical of those used during testing. Program the dynamometer to coast down 

over the dynamometer operational speed range (typically from a speed of 80 mph through 

a minimum speed at or below 10 mph). Perform at least one coastdown over this speed 

range, collecting data over each 10 mph interval.

(3) Repeat the steps in paragraph (c)(2) of this section with the dynamometer inertia and 

road-load coefficients set for the largest vehicle weight that you expect to test.

(4) Determine the average coastdown force, F, for each speed and inertia setting for each 

of the coastdowns performed using the following equation:

I v init vfinal

F

t

 



Eq. 1066.270-1
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Where:

F = the average force measured during the coastdown for each speed interval and inertia 

setting, expressed in lbf·s2/ft and rounded to four significant figures.

I = the dynamometer’s inertia setting, in lbf· s2/ft.

vinit = the speed at the start of the coastdown interval, expressed in ft/s to at least four 

significant figures.

vfinal = the speed at the end of the coastdown interval, expressed in ft/s to at least four 

significant figures.

t = coastdown time for each speed interval and inertia setting, accurate to at least 0.01 s.

Example:

I = 2000 lbm = 65.17 lbf·s2/ft

vinit = 25 mph = 36.66 ft/s

vfinal = 15 mph = 22.0 ft/s

t = 5.00 s

65.17 36.66 22.0

5.00

F

 



F = 191.1 lbf

(5) Calculate the target value of coastdown force, Fref, based on the applicable 

dynamometer parameters for each speed interval and inertia setting.

(6) Compare the mean value of the coastdown force measured for each speed interval and 

inertia setting, Fact , to the corresponding Fref to determine values for coastdown force 

error, Ferror, using the following equation:

act ref

error

ref

100 % F F F

F



 

Eq. 1066.270-2

Example:

Fref = 192 lbf

F act = 191 lbf

error

191 192 100 %

192

F



 

Ferror = 0.5 %

(d) Performance evaluation. The coastdown force error determined in paragraph (c) of 

this section may not exceed the following:

(1) For vehicles at or below 20,000 pounds GVWR, calculate Ferrormax for all speed and 

inertia settings from the following formula:

Ferrormax (%) = (2.2 lbf/Fref)·100

Eq. 1066.270-3
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Example:

Fref = 192 lbf

Ferrormax (%) = (2.2/192)·100 = 1.14%

(2) For vehicles above 20,000 pounds GVWR, the maximum allowable error, Ferrormax, for 

all speed intervals and inertia settings is ±1.0 % or ±39.2 N, whichever is greater.

(e) Remedy for nonconforming dynamometers. If the dynamometer is not able to meet 

this requirement, diagnose and repair the dynamometer before continuing with emission

testing. Diagnosis should include performing the verifications in § 1066.255 and § 

1066.260.

§ 1066.275 Daily dynamometer readiness verification.

(a) Overview. This section describes how to verify that the dynamometer is ready for 

emission testing.

(b) Scope and frequency. Perform this verification upon initial installation, within 1 day

before testing, and after major maintenance.

(c) Procedure. For dynamometers that have an automated process for this verification 

procedure, perform this evaluation by setting the initial speed and final speed and the 

inertial and road-load coefficients as required for the test, using good engineering 

judgment to ensure that these values properly represent in-use operation. Use the 

following procedure if your dynamometer does not perform this verification with an 

automated process:

(1) With the dynamometer in coastdown mode, set the dynamometer inertia to the base 

inertia with the road-load coefficient A set to 20 lbf (or a force that results in a coastdown 

time of less than 10 minutes) and coefficients B and C set to 0. Program the 

dynamometer to coast down for one 10 mph interval from 55 mph down to 45 mph. If 

your dynamometer is not capable of performing one discrete coastdown, then coast down 

with preset 10 mph intervals that include a 55 mph to 45 mph interval.

(2) Perform the coastdown.

(3) Determine the coastdown force and coastdown force error using Eqs. 1066.270-1 and 

1066.270-2.

(d) Performance evaluation. The coastdown force error determined in paragraph (c) of 

this section may not exceed the following:

(1) For vehicles at or below 20,000 pounds GVWR, ±1.0 % or ±9.8 N (±2.2 lbf), 

whichever is greater. 

(2) For vehicles above 20,000 pounds GVWR, ±1.0 % or ±39.2 N (±8.8 lbf), whichever 

is greater.

(e) Remedy for nonconforming dynamometers. If the verification results fail to meet the 

performance criteria in paragraph (d) of this section, perform the procedure up to two 

additional times. If the dynamometer is consistently unable to meet the performance 

criteria, diagnose and repair the dynamometer before continuing with emission testing. 

Diagnosis should include performing the verifications in § 1066.255 and § 1066.260.

§ 1066.290 Verification of speed accuracy for the driver’s aid.
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Use good engineering judgment to provide a driver’s aid that facilitates compliance with 

the requirements of § 1066.425. Verify the speed accuracy of the driver’s aid as 

described in § 1066.235. 

Subpart D—COASTDOWN

§ 1066.301 Overview of coastdown procedures.

(a) The coastdown procedures described in this subpart are used to determine the load 

coefficients (A, B, and C) for the simulated road-load equation in § 1066.210(d)(3).

(b) The general procedure for performing coastdown tests and calculating load 

coefficients is described in SAE J1263 and SAE J2263 (incorporated by reference in § 

1066.1010). This subpart specifies certain deviations from those procedures for certain 

applications.

(c) Use good engineering judgment for all aspects of coastdown testing. For example, 

minimize the effects of grade by performing coastdown testing on reasonably level 

surfaces and determining coefficients based on average values from vehicle operation in 

opposite directions over the course.

§ 1066.305 Coastdown procedures for motor vehicles at or below 14,000 pounds 

GVWR.

For motor vehicles at or below 14,000 pounds GVWR, develop representative road-load 

coefficients to characterize each test vehicle. Calculate road-load coefficients by

performing coastdowns using the provisions of SAE J1263 and SAE J2263 (incorporated 

by reference in § 1066.1010). Perform coastdowns at a starting speed as specified in 

SAE J2263, or at the highest speed from the range of applicable duty cycles. Use the 

same road-load coefficients for all duty cycles. However, if your test conditions are 

substantially different from the conditions represented by your road-load coefficients, 

such as cold temperature testing, you may use good engineering judgment to develop 

separate road-load coefficients.

§ 1066.310 Coastdown procedures for vehicles above 14,000 pounds GVWR.

This section describes coastdown procedures that are unique to vehicles above 14,000 

pounds GVWR. These procedures are valid for calculating road-load coefficients for 

chassis and post-transmission powerpack testing and for calculating drag area (CDA) for 

use in the GEM simulation tool under 40 CFR part 1037.

(a) Determine road-load coefficients by performing a minimum of 16 valid coastdown 

runs (8 in each direction). 

(b) Follow the provisions of Sections 1 through 9 of SAE J1263 and SAE J2263 

(incorporated by reference in § 1066.1010), except as described in this paragraph (b). 

The terms and variables identified in this paragraph (b) have the meaning given in SAE 

J1263 or J2263 unless specified otherwise.

(1) The test condition specifications of SAE J1263 apply except as follows for wind and 

road conditions:
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(i) We recommend that you do not perform coastdown testing on days for which winds 

are forecast to exceed 6.0 mph.

(ii) The grade of the test track or road must not be excessive (considering factors such as 

road safety standards and effects on the coastdown results). Road conditions should 

follow Section 7.4 of SAE J1263, except that road grade may exceed 0.5%. If road grade 

is greater than 0.02% over the length of the test surface, you must incorporate into the 

analysis road grade as a function of distance along the length of the test surface. Use 

Section 11.5 of SAE J2263 to calculate the force due to grade.

(2) Operate the vehicle at a top speed above 70 mph, or at its maximum achievable speed 

if it cannot reach 70 mph. If a vehicle is equipped with a vehicle speed limiter that is set 

for a maximum speed below 70 mph, you must disable the vehicle speed limiter. Start 

the test at or above 70 mph, or at the vehicle’s maximum achievable speed if it cannot 

reach 70 mph. Collect data through a minimum speed at or below 15 mph. Data analysis 

for valid coastdown runs must include the range of vehicle speeds specified in this 

paragraph (b)(2).

(3) Gather data regarding wind speed and direction, in coordination with time-of-day

data, using at least one stationary electro-mechanical anemometer and suitable data 

loggers meeting the specifications of SAE J1263, as well as the following additional 

specifications for the anemometer placed adjacent to the test surface:

(i) Calibrate the equipment by running the zero-wind and zero-angle calibrations within 

24 hours before conducting the coastdown procedures. If the coastdown procedures are 

not complete 24 hours after calibrating the equipment, repeat the calibration for another 

24 hours of data collection.

(ii) Record the location of the anemometer using a GPS measurement device adjacent to 

the test surface (approximately) at the midway distance along the test surface used for 

coastdowns.

(iii) Position the anemometer such that it will be at least 2.5 but not more than 3.0 vehicle 

widths from the test vehicle’s centerline as the test vehicle passes the anemometer.

(iv) Mount the anemometer at a height that is within 6 inches of half the test vehicle’s 

maximum height.

(v) Place the anemometer at least 50 feet from the nearest tree and at least 25 feet from 

the nearest bush (or equivalent roadside features).

(vi) The height of the grass surrounding the stationary anemometer may not exceed 10% 

of the anemometer’s mounted height, within a radius equal to the anemometer’s mounted 

height.

(4) You may split runs as per Section 9.3.1 of SAE J2263, but we recommend whole 

runs. If you split a run, analyze each portion separately, but count the split runs as one 

run with respect to the minimum number of runs required.

(5) You may perform consecutive runs in a single direction, followed by consecutive runs 

in the opposite direction, consistent with good engineering judgment. Harmonize starting 

and stopping points to the extent practicable to allow runs to be paired.

(6) All valid coastdown run times in each direction must be within 2.0 standard 

deviations of the mean of the valid coastdown run times (from the specified maximum 

speed down to 15 mph) in that direction. Eliminate runs outside this range. After 
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eliminating these runs you must have at least eight valid runs in each direction. You may

use coastdown run times that do not meet these standard deviation requirements if we

approve it in advance. In your request, describe why the vehicle is not able to meet the 

specified standard deviation requirements and propose an alternative set of requirements.

(7) Analyze data for chassis and post-transmission powerpack testing or for use in the 

GEM simulation tool as follows:

(i) Follow the procedures specified in Section 10 of SAE J1263 or Section 11 of SAE 

J2263 to calculate coefficients for chassis and post-transmission powerpack testing.

(ii) Determine drag area, CDA, as follows instead of using the procedure specified in 

Section 10 of SAE J1263:

(A) Measure vehicle speed at fixed intervals over the coastdown run (generally at 10 Hz), 

including speeds at or above 15 mph and at or below the specified maximum speed. 

Establish the elevation corresponding to each interval as described in SAE J2263 if you 

need to incorporate the effects of road grade.

(B) Calculate the vehicle’s effective mass, Me, in kg by adding 56.7 kg to the measured 

vehicle mass for each tire making road contact. This accounts for the rotational inertia of 

the wheels and tires.

(C) Calculate the road-load force for each measurement interval, Fi, using the following 

equation:

i i 1

i e

v v F M

t

    



Eq. 1066.310-1

Where:

i = an interval counter, starting with i=1 for the first interval. The designation (i-1) 

corresponds to the end of the previous interval or, for the first interval, to the start of the 

test run.

Me = the vehicle’s effective mass, expressed to at least the nearest 0.1 kg. 

v = vehicle speed at the beginning and end of the measurement interval.

Δt = elapsed time over the measurement interval, in seconds.

(D) Plot the data from all the coastdown runs on a single plot of Fi vs. vi

2

to determine the 

slope correlation, D, based on the following equation:

2

i e m i

h

F M g A D v

s



     



Eq. 1066.310-2

Where:

g = gravitational acceleration = 9.81 m/s2.

Δh = change in elevation over the measurement interval, in m. Assume Δh = 0 if you are 

not correcting for grade. 

Δs = distance the vehicle travels down the road during the measurement interval, in m.

Am = the calculated value of the y-intercept based on the curve-fit.

(E) Calculate drag area, CDA, in m2using the following equation:
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adj

D

2 D

C A







Eq. 1066.310-3

Where:

ρ = air density at reference conditions = 1.17 kg/m3.

adj

act

98.21

293

T

D D

p

   

          

Eq. 1066.310-4

T = mean ambient absolute temperature during testing, in K.

act p = average ambient pressuring during the test, in kPa.

(8) Determine the A, B, and C coefficients identified in § 1066.210 as follows:

(i) For chassis and post-transmission powerpack testing, follow the procedures specified 

in Section 10 of SAE J1263 or Section 12 of SAE J2263.

(ii) For the GEM simulation tool, use the following values:

A = Am

B = 0

C = Dadj

§ 1066.315 Dynamometer road-load setting.

Determine dynamometer road-load settings for chassis testing by following SAE J2264 

(incorporated by reference in § 1066.1010).

Subpart E— PREPARING VEHICLES AND RUNNING AN EXHAUST 

EMISSION TEST

§ 1066.401 Overview.

(a) Use the procedures detailed in this subpart to measure vehicle emissions over a 

specified drive schedule. Different procedures may apply for criteria pollutants and 

greenhouse gas emissions as described in the standard-setting part. This subpart 

describes how to-

(1) Determine road-load power, test weight, and inertia class.

(2) Prepare the vehicle, equipment, and measurement instruments for an emission test.

(3) Perform pre-test procedures to verify proper operation of certain equipment and 

analyzers and to prepare them for testing.

(4) Record pre-test data.

(5) Sample emissions.

(6) Record post-test data.

(7) Perform post-test procedures to verify proper operation of certain equipment and 

analyzers.

(8) Weigh PM samples.

(b) The overall test generally consists of prescribed sequences of fueling, parking, and 

driving at specified test conditions. An exhaust emission test generally consists of 
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measuring emissions and other parameters while a vehicle follows the drive schedules 

specified in the standard-setting part. There are two general types of test cycles:

(1) Transient cycles. Transient test cycles are typically specified in the standard-setting 

part as a second-by-second sequence of vehicle speed commands. Operate a vehicle over 

a transient cycle such that the speed follows the target values. Proportionally sample 

emissions and other parameters and calculate emission rates as specified in subpart G of 

this part to calculate emissions. The standard-setting part may specify three types of 

transient testing based on the approach to starting the measurement, as follows:

(i) A cold-start transient cycle where you start to measure emissions just before starting 

an engine that has not been warmed up.

(ii) A hot-start transient cycle where you start to measure emissions just before starting a 

warmed-up engine.

(iii) A hot-running transient cycle where you start to measure emissions after an engine is 

started, warmed up, and running.

(2) Cruise cycles. Cruise test cycles are typically specified in the standard-setting part as 

a discrete operating point that has a single speed command.

(i) Start a cruise cycle as a hot-running test, where you start to measure emissions after 

the engine is started and warmed up and the vehicle is running at the target test speed.

(ii) Sample emissions and other parameters for the cruise cycle in the same manner as a 

transient cycle, with the exception that the reference speed value is constant. Record 

instantaneous and mean speed values over the cycle.

§ 1066.405 Vehicle preparation and preconditioning.

Prepare the vehicle for testing (including measurement of evaporative and refueling 

emissions if appropriate), as described in the standard-setting part.

§ 1066.410 Dynamometer test procedure.

(a) Dynamometer testing may consist of multiple drive cycles with both cold-start and 

hot-start portions, including prescribed soak times before each test interval. The 

standard-setting part identifies the driving schedules and the associated sample intervals, 

soak periods, engine startup and shutdown procedures, and operation of accessories, as 

applicable. Not every test interval includes all these elements.

(b) Place the vehicle onto the dynamometer without starting the engine (for cold-start test 

cycles) or drive the vehicle onto the dynamometer (for hot-start and hot-running cycles 

only) and position a fan that directs cooling air to the vehicle during dynamometer 

operation as described in this paragraph (b). This generally requires squarely positioning 

the fan in front of the vehicle and directing the airflow to the vehicle’s radiator. Use 

good engineering judgment to design and configure fans to cool the test vehicle in a way

that properly simulates in-use operation, consistent with the specifications of § 1066.105. 

Except for the following special cases, use a road-speed modulated fan meeting the 

requirements of § 1066.105(c)(2) that is placed within 90 cm of the front of the vehicle 

and ensure that the engine compartment cover (i.e., hood) is closed:
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(1) For vehicles above 14,000 pounds GVWR, use a fan meeting the requirements of § 

1066.105(d) that is placed within 90 cm of the front of the vehicle and ensure that the 

engine compartment cover is closed.

(2) For FTP, LA-92, US06, or HFET testing of vehicles at or below 14,000 pounds

GVWR, you may use a fixed-speed fan as specified in the following table, with the 

engine compartment cover open:

TABLE 1 OF § 1066.410–FIXED-SPEED FAN CAPACITY AND 

POSITION SPECIFICATIONS FOR VEHICLES AT OR BELOW 14,000 POUNDS GVWR

Test cycle Maximum fan capacity Approximate distance from the 

front of the vehicle

FTP Up to 2.50 m

3

/s 0 to 30 cm

US06 Up to 7.10 m

3

/s 0 to 60 cm

LA-92 Up to 7.10 m

3

/s 0 to 60 cm

HFET Up to 2.50 m

3

/s 0 to 30 cm

(3) For SC03 and AC17 testing, use a road-speed modulated fan meeting the 

requirements of § 1066.105(c)(5) that is placed within 60 to 90 cm of the front of the 

vehicle and ensure that the engine compartment cover is closed. Position the discharge 

nozzle such that its lowest point is not more than 16 cm above the floor of the test cell.

(c) Record the vehicle’s speed trace based on the time and speed data from the 

dynamometer at the recording frequencies given in Table 1 of § 1066.125. Record speed 

to at least the nearest 0.01 mph and time to at least the nearest 0.1 s.

(d) You may perform practice runs for operating the vehicle and the dynamometer 

controls to meet the driving tolerances specified in § 1066.425 or adjust the emission 

sampling equipment. Verify that the accelerator pedal allows for enough control to 

closely follow the prescribed driving schedule. We recommend that you verify your 

ability to meet the minimum dilution factor requirements of § 1066.110(b)(2)(iii)(B) 

during these practice runs.

(e) Inflate tires on drive wheels according to the vehicle manufacturer’s specifications. 

The tire pressure for drive wheels must be the same for dynamometer operation and for 

dynamometer coastdown procedures used for determining road-load coefficients. Report 

these measured tire pressure values with the test results. 

(f) Tie down or load the test vehicle as needed to provide a normal force at the tire and 

dynamometer roll interface to prevent wheel slip. For vehicles above 14,000 pounds 

GVWR, report this measured force with the test results.

(g) Use good engineering judgment when testing vehicles in four-wheel drive or allwheel drive mode. (For purposes of this paragraph (g), the term four-wheel drive 

includes other multiple drive-axle configurations.) This may involve testing on a 

dynamometer with a separate dynamometer roll for each drive axle; or two drive axles 

may use a single roll, as described in § 1066.210(d)(1); or you may deactivate the second 

set of drive wheels and operate the vehicle on a single roll. For all vehicles at or below 

14,000 GVWR, we will test your vehicle using the same dynamometer roll arrangement 

that you used. We may also test your vehicle using another dynamometer roll 

arrangement for information-gathering purposes. If we choose to perform additional 
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testing that requires vehicle modifications, we will ask you to configure the vehicle 

appropriately.

(h) Determine test weight as follows:

(1) For vehicles at or below 14,000 pounds GVWR, determine ETW as described in § 

1066.805. Set dynamometer vehicle inertia, I, based on dynamometer type, as follows: 

(i) For two-wheel drive dynamometers, set I = ETW.

(ii) For four-wheel drive dynamometers, set I = 0.985∙ETW.

(2) For vehicles above 14,000 pounds GVWR, determine the vehicle’s effective mass as 

described in § 1066.310 and use this as the test weight.

(i) Warm up the dynamometer as recommended by the dynamometer manufacturer.

(j) Following the test, determine the actual driving distance by counting the number of 

dynamometer roll or shaft revolutions, or by integrating speed over the course of testing 

from a high-resolution encoder system.

§ 1066.415 Vehicle operation.

This section describes how to test a conventionally configured vehicle (vehicles with 

transmission shifters, foot pedal accelerators, etc). You may ask us to modify these 

procedures for vehicles that do not have these control features. 

(a) Start the vehicle as follows:

(1) At the beginning of the test cycle, start the vehicle according to the procedure 

described in the owners manual. In the case of HEVs, this would generally involve 

activating vehicle systems such that the engine will start when the vehicle’s control 

algorithms determine that the engine should provide power instead of or in addition to 

power from the rechargeable energy storage system (RESS). Unless we specify

otherwise, engine starting throughout this part generally refers to this step of activating 

the system on HEVs, whether or not that causes the engine to start running.

(2) Place the transmission in gear as described by the test cycle in the standard-setting 

part. During idle operation, apply the brakes if necessary to keep the drive wheels from 

turning.

(b) If the vehicle does not start after your recommended maximum cranking time, wait 

and restart cranking according to your recommended practice. If you do not recommend 

such a cranking procedure, stop cranking after 10 seconds, wait for 10 seconds, then start 

cranking again for up to 10 seconds. You may repeat this for up to three start attempts. 

If the vehicle does not start after three attempts, you must determine and record the 

reason for failure to start. Shut off sampling systems and either turn the CVS off or 

disconnect the laboratory exhaust tubing from the tailpipe during the diagnostic period to 

prevent flow through the exhaust system. Reschedule the vehicle for testing. This may

require performing vehicle preparation and preconditioning if the testing needs to be 

rerun from a cold start. If failure to start occurs during a hot-start test, you may 

reschedule the hot-start test without repeating the cold-start test, as long as you bring the 

vehicle to a hot-start condition before starting the hot-start test.

(c) Repeat the recommended starting procedure if the engine has a false start (i.e., an 

incomplete start).

(d) Take the following steps if the engine stalls:
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(1) If the engine stalls during an idle period, restart the engine immediately and continue 

the test. If you cannot restart the engine soon enough to allow the vehicle to follow the 

next acceleration, stop the driving schedule indicator and reactivate it when the vehicle 

restarts.

(2) Void the test if the vehicle stalls during vehicle operation. If this happens, remove the 

vehicle from the dynamometer, take corrective action, and reschedule the vehicle for 

testing. Record the reason for the malfunction (if determined) and any corrective action. 

See the standard-setting part for instructions about reporting these malfunctions. 

(e) Operate vehicles during testing as follows:

(1) Where we do not give specific instructions, operate the vehicle according to the 

recommendations in the owners manual, unless those recommendations are 

unrepresentative of what may reasonably be expected for in-use operation.

(2) If vehicles have features that preclude dynamometer testing, you may modify these 

features as necessary to allow testing, consistent with good engineering judgment, as long 

as it does not affect your ability to demonstrate that your vehicles comply with the 

applicable standards. Send us written notification describing these changes along with 

supporting rationale.

(3) Operate vehicles during idle as follows:

(i) For vehicles with automatic transmission, operate at idle with the transmission in 

“Drive” with the wheels braked, except that you may shift to “Neutral” for the first idle 

period and for any idle period longer than one minute. If you put the vehicle in “Neutral” 

during an idle, you must shift the vehicle into “Drive” with the wheels braked at least 5 

seconds before the end of the idle period. Note that this does not preclude vehicle 

designs involving engine shutdown during idle.

(ii) For vehicles with manual transmission, operate at idle with the transmission in gear 

with the clutch disengaged, except that you may shift to “Neutral” with the clutch 

engaged for the first idle period and for any idle period longer than one minute. If you 

put the vehicle in “Neutral” during idle, you must shift to first gear with the clutch 

disengaged at least 5 seconds before the end of the idle period. Note that this does not 

preclude vehicle designs involving engine operation with shutdown during idle.

(4) Operate the vehicle with the appropriate accelerator pedal movement necessary to 

follow the scheduled speeds in the driving schedule. Avoid smoothing speed variations 

and unnecessary movement of the accelerator pedal.

(5) Operate the vehicle smoothly, following representative shift speeds and procedures. 

For manual transmissions, the operator shall release the accelerator pedal during each 

shift and accomplish the shift without delay. If the vehicle cannot accelerate at the 

specified rate, operate it at maximum available power until the vehicle speed reaches the 

value prescribed in the driving schedule.

(6) Decelerate as follows:

(i) For vehicles with automatic transmission, use the brakes or accelerator pedal as 

necessary, without manually changing gears, to maintain the desired speed.

(ii) For vehicles with manual transmission, shift gears in a way that represents reasonable 

shift patterns for in-use operation, considering vehicle speed, engine speed, and any other 

relevant variables. Disengage the clutch when the speed drops below 15 mph, when 
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engine roughness is evident, or when good engineering judgment indicates the engine is 

likely to stall. Manufacturers may recommend shift guidance in the owners manual that 

differs from the shift schedule used during testing, as long as both shift schedules are 

described in the application for certification; in this case, we may shift during testing as 

described in the owners manual.

§ 1066.420 Test preparation.

(a) Follow the procedures for PM sample preconditioning and tare weighing as described 

in 40 CFR 1065.590 if you need to measure PM emissions.

(b) For vehicles above 14,000 pounds GVWR with compression-ignition engines, verify

the amount of nonmethane hydrocarbon contamination as described in 40 CFR 

1065.520(g).

(c) Unless the standard-setting part specifies different tolerances, verify at some point 

before the test that ambient conditions are within the tolerances specified in this 

paragraph (c). For purposes of this paragraph (c), “before the test” means any time from 

a point just prior to engine starting (excluding engine restarts) to the point at which 

emission sampling begins.

(1) Ambient temperature must be (20 to 30) °C. See § 1066.425(h) for circumstances 

under which ambient temperatures must remain within this range during the test. 

(2) Dilution air conditions must meet the specifications in § 1066.110(b)(2). We 

recommend verifying dilution air conditions just before starting each test interval.

(d) Control test cell ambient air humidity as follows:

(1) For vehicles at or below 14,000 pounds GVWR, follow the humidity requirements in 

Table 1 of this section, unless the standard-setting part specifies otherwise. When 

complying with humidity requirements in the table, where no tolerance is specified, use 

good engineering judgment to maintain the humidity level near the specified value within 

the limitations of your test facility.

(2) For vehicles above 14,000 pounds GVWR, you may test vehicles at any humidity.

TABLE 1 OF § 1066.420–TEST CELL HUMIDITY REQUIREMENTS

Test cycle

Humidity requirement 

(grains H2O per 

pound dry air)

Tolerance (grains H2O 

per pound dry air)

AC17 69 ± 5 average, 

± 10 instantaneous

FTP1and LA-92 50

HFET 50

SC03 100 ± 5

US06 50

1

FTP humidity requirement does not apply for cold (-7°C), 

intermediate (10 °C), and hot (35 °C) temperature testing.

(e) You may perform a final calibration of proportional-flow control systems, which may

include performing practice runs.

(f) You may perform the following procedure to precondition sampling systems:

(1) Operate the vehicle over the test cycle.
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(2) Operate any dilution systems at their expected flow rates. Prevent aqueous 

condensation in the dilution systems as described in 40 CFR 1065.140(c)(6), taking into 

account allowances given in § 1066.110(b)(2)(iv). 

(3) Operate any PM sampling systems at their expected flow rates.

(4) Sample PM using any sample media. You may change sample media during 

preconditioning. You must discard preconditioning samples without weighing them.

(5) You may purge any gaseous sampling systems during preconditioning.

(6) You may conduct calibrations or verifications on any idle equipment or analyzers 

during preconditioning.

(g) Take the following steps before emission sampling begins:

(1) For batch sampling, connect clean storage media, such as evacuated bags or tareweighed filters.

(2) Start all measurement instruments according to the instrument manufacturer’s 

instructions and using good engineering judgment.

(3) Start dilution systems, sample pumps, and the data-collection system.

(4) Pre-heat or pre-cool heat exchangers in the sampling system to within their operating 

temperature tolerances for a test.

(5) Allow heated or cooled components such as sample lines, filters, chillers, and pumps 

to stabilize at their operating temperatures.

(6) Adjust the sample flow rates to desired levels using bypass flow, if desired. 

(7) Zero or re-zero any electronic integrating devices before the start of any test interval.

(8) Select gas analyzer ranges. You may not switch the gain of an analyzer’s analog 

operational amplifier(s) during a test. However, you may switch (automatically or 

manually) gas analyzer ranges during a test if such switching changes only the range over 

which the digital resolution of the instrument is applied. For batch analyzers, select 

ranges before final bag analysis.

(9) Zero and span all continuous gas analyzers using gases that meet the specifications of 

40 CFR 1065.750. For FID analyzers, you may account for the carbon number of your 

span gas either during the calibration process or when calculating your final emission 

value. For example, if you use a C3H8 span gas of concentration 200 ppm (mol/mol), 

you may span the FID to respond with a value of 600 ppm (mol/mol) of carbon or 200 

ppm of propane. However, if your FID response is equivalent to propane, include a 

factor of three to make the final calculated hydrocarbon mass consistent with a molar 

mass of 13.875389. When utilizing an NMC-FID, span the FID analyzer consistent with 

the determination of their respective response factors, RF, and penetration fractions, PF, 

according to 40 CFR 1065.365.

(10) We recommend that you verify gas analyzer responses after zeroing and spanning by

sampling a calibration gas that has a concentration near one-half of the span gas 

concentration. Based on the results, use good engineering judgment to decide whether or 

not to re-zero, re-span, or re-calibrate a gas analyzer before starting a test.

(11) If you correct for dilution air background concentrations of associated engine 

exhaust constituents, start sampling and recording background concentrations at the same 

time you start sampling exhaust gases.

(12) Turn on cooling fans immediately before starting the test.
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(h) Proceed with the test sequence described in § 1066.425.

§ 1066.425 Performing emission tests.

(a) See the standard-setting part for drive schedules. These are defined by a smooth fit of 

a specified speed vs. time sequence.

(b) The driver must attempt to follow the target schedule as closely as possible, consistent 

with the specifications in paragraph (b) of this section. Instantaneous speeds must stay

within the following tolerances:

(1) The upper limit is 2.0 mph higher than the highest point on the trace within 1.0 s of 

the given point in time.

(2) The lower limit is 2.0 mph lower than the lowest point on the trace within 1.0 s of the 

given time.

(3) The same limits apply for vehicle operation without exhaust measurements, such as 

vehicle preconditioning and warm-up, except that the upper and lower limits for speed 

values are ±4.0 mph. In addition, up to three occurrences of speed variations greater than 

the tolerance are acceptable for vehicle operation in which no exhaust emission standards 

apply, as long as they occur for less than 15 seconds on any occasion and are clearly 

documented as to the time and speed at that point of the driving schedule.

(4) Void the test if you do not maintain speed values as specified in this paragraph (b), 

except as allowed by this paragraph (b)(4). Speed variations (such as may occur during 

gear changes or braking spikes) may occur as follows, as long as such variations are 

clearly documented, including the time and speed values and the reason for the deviation:

(i) Speed variations greater than the specified limits are acceptable for up to 2.0 seconds 

on any occasion.

(ii) For vehicles that are not able to maintain acceleration as specified in § 

1066.415(e)(5), do not count the insufficient acceleration as being outside the specified 

limits.

(5) We may approve an alternate test cycle and cycle-validation criteria for vehicles that 

do not have enough power to follow the specified driving trace. The alternate driving 

specifications must be based on making best efforts to maintain acceleration and speed to 

follow the specified test cycle. We must approve these alternate driving specifications 

before you perform this testing.

(c) Figure 1 and Figure 2 of this section show the range of acceptable speed tolerances for 

typical points during testing. Figure 1 of this section is typical of portions of the speed 

curve that are increasing or decreasing throughout the 2-second time interval. Figure 2 of 

this section is typical of portions of the speed curve that include a maximum or minimum 

value.
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Figure 1 of § 1066.425—Example of the allowable ranges for the driver’s trace

Figure 2 of § 1066.425—Example of the allowable ranges for the driver’s trace

(d) Start testing as follows:

(1) If a vehicle is already running and warmed up, and starting is not part of the test 

cycle, operate the vehicle as follows:

(i) For transient test cycles, control vehicle speeds to follow a drive schedule consisting 

of a series of idles, accelerations, cruises, and decelerations.

1.0 s

Time

S

p

e

e

d

Allowable 

Range

2.0 mph

2.0 mph

1.0 s

1.0 s

Time

S

p

e

e

d

Allowable 

Range

2.0 mph

2.0 mph

1.0 s
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(ii) For cruise test cycles, control the vehicle operation to match the speed of the first 

interval of the test cycle. Follow the instructions in the standard-setting part to determine 

how long to stabilize the vehicle during each interval, how long to sample emissions at 

each interval, and how to transition between intervals.

(2) If engine starting is part of the test cycle, start recording continuous data, turn on any

electronic integrating devices, and start batch sampling before starting the engine. 

Initiate the driver’s trace when the engine starts.

(e) Perform the following at the end of each test interval, except as specified in standardsetting part:

(1) Shut down the vehicle if it is part of the test cycle or if testing is complete.

(2) Continue to operate all sampling and dilution systems to allow the response times to 

elapse. Then stop all sampling and recording, including background sampling. Finally, 

stop any integrating devices and indicate the end of the duty cycle in the recorded data.

(f) If testing involves engine shutdown followed by another test interval, start a timer for 

the vehicle soak when the engine shuts down. Turn off cooling fans, close the engine 

compartment cover (if applicable), and turn off the CVS or disconnect the exhaust tube 

from the vehicle’s tailpipe(s) unless otherwise instructed in the standard-setting part. If 

testing is complete, disconnect the laboratory exhaust tubing from the vehicle’s 

tailpipe(s) and drive the vehicle from the dynamometer.

(g) Take the following steps after emission sampling is complete:

(1) For any proportional batch sample, such as a bag sample or PM sample, verify that 

proportional sampling was maintained according to 40 CFR 1065.545. Void any samples 

that did not maintain proportional sampling according to those specifications.

(2) Place any used PM samples into covered or sealed containers and return them to the 

PM-stabilization environment. Follow the PM sample post-conditioning and total 

weighing procedures in 40 CFR 1065.595. 

(3) As soon as practical after the interval or test cycle is complete, or optionally during 

the soak period if practical, perform the following:

(i) Begin drift check for all continuous gas analyzers as described in paragraph (g)(5) of 

this section and zero and span all batch gas analyzers as soon as practical before any 

batch sample analysis. You may perform this batch analyzer zero and span before the 

end of the test interval.

(ii) Analyze any conventional gaseous batch samples (HC, CH4, CO, NOx, and CO2) no 

later than 30 minutes after a test interval is complete, or during the soak period if 

practical. Analyze background samples no later than 60 minutes after the test interval is 

complete.

(iii) Analyze nonconventional gaseous batch samples (including background), such as 

NMHCE, N2O, or NMOG sampling with ethanol, as soon as practicable using good 

engineering judgment.

(4) If an analyzer operated above 100 % of its range at any time during the test, perform 

the following steps:

(i) For batch sampling, re-analyze the sample using the lowest analyzer range that results 

in a maximum instrument response below 100 %. Report the result from the lowest range 

from which the analyzer operates below 100 % of its range.
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(ii) For continuous sampling, repeat the entire test using the next higher analyzer range. 

If the analyzer again operates above 100 % of its range, repeat the test using the next 

higher range. Continue to repeat the test until the analyzer consistently operates at less 

than 100 % of its range. Keep records of any tests where the analyzer exceeds its range. 

We may consider these results to determine that the test vehicle exceeded an emission 

standard, consistent with good engineering judgment.

(5) After quantifying exhaust gases, verify drift as follows:

(i) For batch and continuous gas analyzers, record the mean analyzer value after 

stabilizing a zero gas to the analyzer. Stabilization may include time to purge the 

analyzer of any sample gas, plus any additional time to account for analyzer response. 

(ii) Record the mean analyzer value after stabilizing the span gas to the analyzer. 

Stabilization may include time to purge the analyzer of any sample gas, plus any

additional time to account for analyzer response.

(iii) Use these data to verify that analyzer drift does not exceed 2.0 % of the analyzer full 

scale.

(h) Measure and record ambient pressure. Measure and record ambient temperature 

continuously to verify that it remains within the temperature range specified in § 

1066.420(c)(1) throughout the test. Also measure humidity if required, such as for 

correcting NOx emissions, or meeting the requirements of § 1066.420(d).

(i) [Reserved]

(j) For vehicles at or below 14,000 pounds GVWR, determine overall driver accuracy as 

follows:

(1) Compare the following drive-cycle metrics, based on measured vehicle speeds, to a 

reference value based on the target cycle that would have been generated by driving 

exactly to the target trace as described in SAE J2951 (incorporated by reference in § 

1066.1010):

(i) Determine the Energy Economy Rating as described in Section 5.4 of SAE J2951. 

(ii) Determine the Absolute Speed Change Rating as described in Section 5.5 of SAE 

J2951.

(iii) Determine the Inertia Work Rating as described in Section 5.6 of SAE J2951.

(iv) Determine the phase-weighted composite Energy Based Drive Metrics for the criteria 

specified in this paragraph (j)(1) as described in Section 5.7 of SAE J2951.

(2) The standard-setting part may require you to give us 10 Hz data to characterize both 

target and actual values for cycle energy. Calculate target values based on the vehicles 

speeds from the specified test cycle.

Subpart F—ELECTRIC VEHICLES AND HYBRID ELECTRIC VEHICLES

§ 1066.501 Overview.

Use the following procedures to test EVs and HEVs (including PHEVs):

(a) Correct the results for Net Energy Change of the RESS as follows: 

(1) For all sizes of EVs, follow SAE J1634 (incorporated by reference in § 1066.1010). 

(2) For HEVs at or below 14,000 pounds GVWR, follow SAE J1711 (incorporated by 

reference in § 1066.1010) except as described in this paragraph (a). Disregard provisions 
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of SAE J1711 that differ from this part or the standard-setting part if they are not specific 

to HEVs. Apply the following adjustments and clarifications to SAE J1711:

(i) If the procedure calls for charge-sustaining operation, start the drive with a State of 

Charge that is appropriate to ensure charge-sustaining operation for the duration of the 

drive. Take steps other than emission measurements to confirm that vehicles are in 

charge-sustaining mode for the duration of the drive.

(ii) We may approve the use of the alternate End-of-Test criterion in Section 3.9.1 of 

SAE J1711 and the Net Energy Change correction in Appendix C of SAE J1711 if the 

specified criterion and correction are insufficient or inappropriate for establishing the 

transition between charge-depleting and charge-sustaining operation.

(iii) Appendix C of SAE J1711 may be used to correct final fuel economy values, CO2

emissions, and carbon-related exhaust emissions, but may not be used to correct 

measured values for criteria pollutant emissions.

(iv) You may test subject to a measurement accuracy of ±0.3 % of full scale in place of 

the measurement accuracy specified in Section 4.2a of SAE J1711.

(3) For HEVs above 14,000 pounds GVWR, follow SAE J2711 (incorporated by

reference in § 1066.1010) for requirements related to charge-sustaining operation.

(4) Use an integration frequency of 1 to 20 Hz for power analyzers to verify compliance 

with current and voltage specifications.

(b) This paragraph (b) applies for vehicles that include an engine-powered generator or 

other auxiliary power unit that provides motive power. For example, this would include a 

vehicle that has a small gasoline engine that generates electricity to charge batteries. 

Unless we approve otherwise, measure emissions for all test cycles when such an engine 

is operating. For each test cycle for which emissions are not measured, you must validate 

that such engines are not operating at any time during the test cycle.

(c) You may stop emission sampling anytime the engine is turned off, consistent with 

good engineering judgment. This is intended to allow for higher concentrations of dilute 

exhaust gases and more accurate measurements. Take steps to account for exhaust 

transport delay in the sampling system, and be sure to integrate over the actual sampling 

duration when determining Vmix.

Subpart G—CALCULATIONS

§ 1066.601 Overview.

(a) This subpart describes calculations used to determine emission rates. See the 

standard-setting part and the other provisions of this part to determine which equations 

apply for your testing. This subpart describes how to–

(1) Use the signals recorded before, during, and after an emission test to calculate 

distance-specific emissions of each regulated pollutant.

(2) Perform calculations for calibrations and performance checks.

(3) Determine statistical values.

(b) You may use data from multiple systems to calculate test results for a single emission 

test, consistent with good engineering judgment. You may also make multiple 

measurements from a single batch sample, such as multiple weighing of a PM filter or 
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multiple readings from a bag sample. Although you may use an average of multiple 

measurements from a single test, you may not use test results from multiple emission 

tests to report emissions. We allow weighted means where appropriate, such as for 

sampling onto a PM filter over the FTP. You may discard statistical outliers, but you 

must report all results.

§ 1066.605 Mass-based and molar-based exhaust emission calculations.

(a) Calculate your total mass of emissions over a test cycle as specified in paragraph (c) 

of this section or in 40 CFR part 1065, subpart G, as applicable.

(b) See the standard-setting part for composite emission calculations over multiple test 

intervals and the corresponding weighting factors.

(c) Perform the following sequence of preliminary calculations to correct recorded 

concentration measurements before calculating mass emissions in paragraphs (d) and (e) 

of this section:

(1) For vehicles above 14,000 pounds GVWR, correct all THC and CH4 concentrations 

for initial contamination as described in 40 CFR 1065.660(a), including continuous 

readings, sample bag readings, and dilution air background readings. This correction is 

optional for vehicles at or below 14,000 pounds GVWR.

(2) Correct all concentrations measured on a “dry” basis to a “wet” basis, including 

dilution air background concentrations.

(3) Calculate all NMHC and CH4 concentrations, including dilution air background 

concentrations, as described in 40 CFR 1065.660.

(4) For vehicles at or below 14,000 pounds GVWR, calculate HC concentrations, 

including dilution air background concentrations, as described in this section, and as 

described in § 1066.635 for NMOG. For emission testing of vehicles above 14,000 

pounds GVWR, with fuels that contain 25 % or more oxygenated compounds by volume, 

calculate THCE and NMHC concentrations, including dilution air background 

concentrations, as described in 40 CFR part 1065, subpart I.

(5) Correct NOx emission values for intake-air humidity as described in § 1066.615.

(6) Correct all gaseous concentrations for dilution air background as described in § 

1066.610.

(7) Correct all PM filter masses for sample media buoyancy as described in 40 CFR 

1065.690.

(d) Calculate the emission mass of each gaseous pollutant using the following equation:

m V [emission] mix [emission] [emission]     x c

Eq. 1066.605-1

Where:

m[emission] = emission mass over the test interval.

Vmix = total dilute exhaust volume over the test interval, corrected to standard reference 

conditions, and corrected for any volume removed for emission sampling and for any 

volume change from adding secondary dilution air.

ρ[emission] = density of the appropriate chemical species as given in § 1066.1005(f).
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x[emission] = measured emission concentration in the sample, after dry-to-wet and 

background corrections.

c = 10-2for emission concentrations in %, and 10-6for emission concentrations in ppm.

Example:

Vmix = 170.878 m3(from paragraph (f) of this section) 

ρNOx = 1913 g/m3

xNOx = 0.9721 ppm

c = 10-6

6

NOx m 170.878 1913 0.9721 10 0.3177 g 

    

(e) Calculation of the emission mass of PM, mPM, is dependent on how many PM filters 

you use, as follows:

(1) Except as specified in paragraphs (e)(2) and (3) of this section, calculate mPM using 

the following equation:

 

mix

PM PMfil PMbkgnd

PMstd sdastd

V

m m m

V V

 

    

  

Eq. 1066.605-2

Where:

mPM = mass of particulate matter emissions over the test interval, as described in § 

1066.815(b)(1), (2), and (3).

Vmix = total dilute exhaust volume over the test interval, corrected to standard reference 

conditions, and corrected for any volume removed for emission sampling and for any 

volume change from adding secondary dilution air.

Vsdastd = total volume of secondary dilution air sampled through the filter over the test 

interval, corrected to standard temperature and pressure.

mPMfil = mass of particulate matter emissions on the filter over the test interval.

mPMbkgnd = mass of particulate matter on the background filter.

Example:

Vmix = 170.878 m3(from paragraph (f) of this section)

VPMstd = 0.925 m3(from paragraph (f) of this section)

Vsdastd = 0.527 m3(from paragraph (f) of this section)

mPMfil = 0.0000045 g

mPMbkgnd = 0.0000014 g

PM  

170.878 0.0000045 0.0000014 0.00133 g

0.925 0.527

m

 

        

(2) If you sample PM onto a single filter as described in § 1066.815(b)(4), calculate mPM

using the following equation:
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 

 

 

 

mix

PM PMfil PMbkgnd

ct-PMstd ct-sdastd ht-PMstd ht-sdastd

s-PMstd s-sdastd 0.43 0.57

V

m m m

V V V V

V V

   

  

 

  

 

Eq. 1066.605-3

Where:

mPM = mass of particulate matter emissions over the entire FTP as sampled according to § 

1066.815(b)(4).

Vmix = total dilute exhaust volume over the test interval, corrected to standard reference 

conditions, and corrected for any volume removed for emission sampling and for any 

volume change from adding secondary dilution air.

V[interval]-PMstd = total volume of dilute exhaust sampled through the filter over the test 

interval (ct = cold transient, s = stabilized, ht = hot transient), corrected to standard 

reference conditions.

V[interval]-sdastd = total volume of secondary dilution air sampled through the filter over the 

test interval (ct = cold transient, s = stabilized, ht = hot transient), corrected to standard 

reference conditions.

mPMfil = mass of particulate matter emissions on the filter over the test interval.

mPMbkgnd = mass of particulate matter on the background filter over the test interval.

Example:

Vmix = 633.691 m3

Vct-PMstd = 0.925 m3

Vct-sdastd = 0.527 m3

Vs-PMstd = 1.967 m3

Vs-sdastd = 1.121 m3

Vht-PMstd = 1.122 m3

Vht-sdastd = 0.639 m

3

mPMfil = 0.0000106 g

mPMbkgnd = 0.0000014 g

 

 

 

PM  

633.691 0.0000106 0.0000014

0.925 0.527 1.122 0.639

1.967 1.121

0.43 0.57

m

   

  

 

  

 

mPM = 0.00222 g

(3) If you sample PM onto a single filter as described in § 1066.815(b)(5), calculate mPM

using the following equation:

       

 

mix

PM PMfil PMbkgnd

ct-PMstd ct-sdastd cs-PMstd cs-sdastd ht-PMstd ht-sdastd hs-PMstd hs-sdastd

0.43 0.57

V

m m m

V V V V V V V V

   

  

     



 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 983 of 1039

Eq. 1066.605-4

Where:

mPM = mass of particulate matter emissions over the entire FTP as sampled according to § 

1066.815(b)(5).

Vmix = total dilute exhaust volume over the test interval, corrected to standard reference 

conditions, and corrected for any volume removed for emission sampling and for any 

volume change from secondary dilution air.

V[interval]-PMstd = total volume of dilute exhaust sampled through the filter over the test 

interval (ct = cold transient, cs = cold stabilized, ht = hot transient, hs = hot stabilized), 

corrected to standard reference conditions.

V[interval]-sdastd = total volume of secondary dilution air sampled through the filter over the 

test interval (ct = cold transient, cs = cold stabilized, ht = hot transient, hs = hot 

stabilized), corrected to standard reference conditions.

mPMfil = mass of particulate matter emissions on the filter over the test interval.

mPMbkgnd = mass of particulate matter on the background filter over the test interval.

Example:

Vmix = 972.121 m3

Vct-PMstd = 0.925 m3

Vct-sdastd = 0.529 m3

Vcs-PMstd = 1.968 m3

Vcs-sdastd = 1.123 m3

Vht-PMstd = 1.122 m3

Vht-sdastd = 0.641 m3

Vhs-PMstd = 1.967 m3

Vhs-sdastd = 1.121 m3

mPMfil = 0.0000229 g

mPMbkgnd = 0.0000014 g

       

PM  

972.121 0.0000229 0.0000014

0.925 0.529 1.968 1.123 1.122 0.641 1.967 1.121

0.43 0.57

m

   

  

     



 

mPM = 0.00401 g

(f) This paragraph (f) describes how to correct flow and flow rates to standard reference 

conditions and provides an example for determining Vmix based on CVS total flow and 

the removal of sample flow from the dilute exhaust gas. You may use predetermined 

nominal values for removed sample volumes, except for flows used for batch sampling.

(1) Correct flow and flow rates to standard reference conditions as needed using the 

following equation:

[flow]act in std

[flow]std

std in

V p T

V

p T

 





Eq. 1066.605-5
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 984 of 1039

Where:

V[flow]std = total flow volume at the flow meter, corrected to standard reference conditions.

V[flow]act = total flow volume at the flow meter at test conditions.

pin = absolute static pressure at the flow meter inlet, measured directly or calculated as 

the sum of atmospheric pressure plus a differential pressure referenced to atmospheric 

pressure.

Tstd = standard temperature.

pstd = standard pressure.

Tin = temperature of the dilute exhaust sample at the flow meter inlet.

Example:

VPMact = 1.071 m3

pin = 101.7 kPa

Tstd = 293.15 K

pstd = 101.325 kPa

Tin = 340.5 K

3

PMstd

1.071 101.7 293.15 0.925 m

101.325 340.5

V

 

 



(2) The following example provides a determination of Vmix based on CVS total flow and 

the removal of sample flow from one dilute exhaust gas analyzer and one PM sampling 

system that is utilizing secondary dilution. Note that your Vmix determination may vary

from Eq. 1066.605-6 based on the number of flows that are removed from your dilute 

exhaust gas and whether your PM sampling system is using secondary dilution. For this 

example, Vmix is governed by the following equation:

V V mix C   VSstd V V gasstd   PMstd Vsdastd

Eq. 1066.605-6

Where:

VCVSstd = total dilute exhaust volume over the test interval at the flow meter, corrected to 

standard reference conditions.

Vgasstd = total volume of sample flow through the gaseous emission bench over the test 

interval, corrected to standard reference conditions.

VPMstd = total volume of dilute exhaust sampled through the filter over the test interval , 

corrected to standard reference conditions.

Vsdastd = total volume of secondary dilution air flow sampled through the filter over the 

test interval, corrected to standard reference conditions.

Example:

Using Eq. 1066.605-5

VCVSstd = 170.451 m3, where VCVSact = 170.721 m3, pin = 101.7 kPa, and Tin = 294.7 K

Using Eq. 1066.605-5

Vgasstd = 0.028 m3, where Vgasact = 0.033 m3, pin = 101.7 kPa, and Tin = 340.5 K

Using Eq. 1066.605-5

VPMstd = 0.925 m3, where VPMact = 1.071 m3, pin = 101.7 kPa, and Tin = 340.5 K
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 985 of 1039

Using Eq. 1066.605-5

Vsdastd = 0.527 m3, where Vsdaact = 0.531 m3, pin = 101.7 kPa, and Tin = 296.3 K

Vmix = 170.451 + 0.028 + 0.925 – 0.527 = 170.878 m3

(g) Calculate total flow volume over a test interval, V[flow], for a CVS or exhaust gas 

sampler as follows: 

(1) Varying versus constant flow rates. The calculation methods depend on 

differentiating varying and constant flow, as follows:

(i) We consider the following to be examples of varying flows that require a continuous 

multiplication of concentration times flow rate: raw exhaust, exhaust diluted with a 

constant flow rate of dilution air, and CVS dilution with a CVS flow meter that does not 

have an upstream heat exchanger or electronic flow control.

(ii) We consider the following to be examples of constant exhaust flows: CVS diluted 

exhaust with a CVS flow meter that has an upstream heat exchanger, an electronic flow 

control, or both.

(2) Continuous sampling. For continuous sampling, you must frequently record a 

continuously updated flow signal. This recording requirement applies for both varying 

and constant flow rates.

(i) Varying flow rate. If you continuously sample from a varying exhaust flow rate, 

calculate V[flow] using the following equation:

[flow] i

i 1

N

V Q t



    

Eq. 1066.605-7

Where:

∆t = 1/frecord Eq. 1066.605-8

Example:

N = 505

QCVS1

 = 0.276 m3

/s

QCVS2

 = 0.294 m3

/s

frecord = 1 Hz

Using Eq. 1066.605-8,

t = 1/1 = 1 s

CVS CVS505 V Q   (0.276 0.294   ... ) 1



VCVS = 170.721 m3

(ii) Constant flow rate. If you continuously sample from a constant exhaust flow rate, use 

the same calculation described in paragraph (g)(2)(i) of this section or calculate the mean 

flow recorded over the test interval and treat the mean as a batch sample, as described in 

paragraph (g)(3)(ii) of this section. 

(3) Batch sampling. For batch sampling, calculate total flow by integrating a varying flow 

rate or by determining the mean of a constant flow rate, as follows:

(i) Varying flow rate. If you proportionally collect a batch sample from a varying 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 986 of 1039

exhaust flow rate, integrate the flow rate over the test interval to determine the total flow 

from which you extracted the proportional sample, as described in paragraph (g)(2)(i) of 

this section. 

(ii) Constant flow rate. If you batch sample from a constant exhaust flow rate, extract a 

sample at a proportional or constant flow rate and calculate V[flow] from the flow from 

which you extract the sample by multiplying the mean flow rate by the time of the test 

interval using the following equation: 

V Q [flow]  t



Eq. 1066.605-9

Example:

QCVS

 = 0.338 m3

/s

t = 505 s 

CVS V   0.338 505

VCVS = 170.69 m3

§ 1066.610 Dilution air background correction.

(a) Correct the emissions in a gaseous sample for background using the following 

equation:

[emission] [emission]dexh [emission]bkgnd

1

x x x 1

DF

   

           

Eq. 1066.610-1

Where:

x[emission]dexh = measured emission concentration in dilute exhaust (after dry-to-wet 

correction, if applicable).

x[emission]bkgnd = measured emission concentration in the dilution air (after dry-to-wet 

correction, if applicable).

DF = dilution factor, as determined in paragraph (b) of this section.

Example:

xNOxdexh = 1.08305 ppm

xNOxbkgnd = 0.12456 ppm

DF = 9.14506

NOx

1

1.08305 0.12456 1 0.97211 ppm

9.14506

x

   

         

(b) Except as specified in paragraph (c) of this section, determine the dilution factor, DF, 

over the test interval using the following equation:

CO2 NMHC CH4 CO

1

1 3.76 1 ( )

2 4 2

DF

x x x x

  



   

                
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 987 of 1039

Eq. 1066.610-2

Where:

xCO2 = amount of CO2 measured in the sample over the test interval.

xNMHC = amount of C1-equivalent NMHC measured in the sample over the test interval.

xCH4 = amount of CH4 measured in the sample over the test interval.

xCO = amount of CO measured in the sample over the test interval.

 = atomic hydrogen-to-carbon ratio of the test fuel. You may measure  or use default 

values from Table 1 of 40 CFR 1065.655.

 = atomic oxygen-to-carbon ratio of the test fuel. You may measure  or use default 

values from Table 1 of 40 CFR 1065.655.

Example:

xCO2 = 1.456 % = 0.01456

xNMHC = 0.84 ppm = 0.00000084

xCH4 = 0.26 ppm = 0.00000026

xCO = 80.4 ppm = 0.0000804

 = 1.92

 = 0.03

 

1

9.14506

1.92 1.92 0.03 1 3.76 1 0.01456 0.00000084 0.00000026 0.0000804

2 4 2

DF      

              

(c) Determine the dilution factor, DF, over the test interval for partial-flow dilution 

sample systems using the following equation:

dexhstd

exhstd

V

DF

V



Eq. 1066.610-3

Where:

Vdexhstd = total dilute exhaust volume sampled over the test interval, corrected to standard 

reference conditions.

Vexhstd = total exhaust volume sampled from the vehicle, corrected to standard reference 

conditions.

Example:

Vdexhstd = 170.9 m3

Vexhstd = 15.9 m3

170.9 11.1

15.4

DF  

(d) Determine the time-weighted dilution factor, DFw, over the duty cycle using the 

following equation:
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 988 of 1039

i

i 1

w

i

i 1 i

1

N

N

t

DF

t

DF













Eq. 1066.610-4

Where:

N = number of test intervals.

i = test interval number

t = duration of the test interval.

DF = dilution factor over the test interval.

Example:

N = 3

DF1 = 14.40

t1 = 505 s

DF2 = 24.48

t2 = 867 s

DF3 = 17.28

t3 = 505 s

w

505 867 505 18.82

111 505 867 505

14.40 24.48 17.28

DF         

                

§ 1066.615 NOx intake-air humidity correction.

You may correct NOx emissions for intake-air humidity as described in this section if the 

standard-setting part allows it. See § 1066.605(c)(1) for the proper sequence for applying 

the NOx intake-air humidity correction.

(a) For vehicles at or below 14,000 pounds GVWR, apply a correction for vehicles with 

reciprocating engines operating over specific test cycles as follows:

(1) Calculate a humidity correction using a time-weighted mean value for ambient 

humidity over the test interval. Calculate absolute ambient humidity, H, using the 

following equation:

 

H2O d

air atmos d

1000 %

%

M p RH H

M p p RH

  



  

Eq. 1066.615-1

Where:

MH2O = molar mass of H2O.

pd = saturated vapor pressure at the ambient dry bulb temperature.

RH = relative humidity of ambient air

Mair = molar mass of air.

patmos = atmospheric pressure.

Example:
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 989 of 1039

MH2O = 18.01528 g/mol

pd = 2.93 kPa

RH = 37.5 %

Mair = 28.96559 g/mol

patmos = 96.71 kPa

 

2

1000 18.01528 2.93 37.5 0.01 7.14741 g H O vapor kg dry air

28.96559 96.71 2.93 37.5 0.01

H

   

 

   

(2) Use the following equation to correct measured concentrations to a reference 

condition of 10.71 grams H2O vapor per kilogram of dry air for the FTP, US06, LA-92, 

SC03, and HFET test cycles:

 

s

NOxdexhcor NOxdexh 1 0.0329 10.71

H

x x

H

 

  

Eq. 1066.615-2

Where:

xNOxdexh = measured dilute NOx emissions.

Hs = humidity scale. Set = 1 for FTP, US06, LA-92, and HFET test cycles. Set = 0.8825 

for the SC03 test cycle.

H = ambient humidity, as determined in paragraph (a)(1) of this section.

Example:

H = 7.14741 g H2O vapor/kg dry air time weighted over the FTP test cycle

xNOxdexh = 1.21 ppm

 

NOxdexhcor

1

1.21 1.08305 ppm

1 0.0329 7.14741 10.71

x   

  

(b) For vehicles above 14,000 pounds GVWR, apply correction factors as described in 40 

CFR 1065.670.

§ 1066.620 Removed water correction.

Correct for removed water if water removal occurs upstream of a concentration 

measurement and downstream of a flow meter used to determine mass emissions over a 

test interval. Perform this correction based on the amount of water at the concentration 

measurement and on the amount of water at the flow meter.

§ 1066.625 Flow meter calibration calculations.

This section describes how to calibrate various flow meters based on mass flow rates. 

Calibrate your flow meter according to 40 CFR 1065.640 instead if you calculate 

emissions based on molar flow rates.

(a) PDP calibration. Perform the following steps to calibrate a PDP flow meter:

(1) Calculate PDP volume pumped per revolution, Vrev, for each restrictor position from 

the mean values determined in § 1066.140:
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 990 of 1039

ref in std

rev

nPDP in std

Q T p

V

f p T

 



 



Eq. 1066.625-1

Where:

Qref

 = mean flow rate of the reference flow meter.

Tin = mean temperature at the PDP inlet.

pstd = standard pressure = 101.325 kPa.

nPDP f = mean PDP speed.

in p = mean static absolute pressure at the PDP inlet.

Tstd = standard temperature = 293.15 K.

Example:

Qref

 = 0.1651 m3

/s

Tin = 299.5 K

pstd = 101.325 kPa

nPDP f = 1205.1 r/min = 20.085 r/s

in p = 98.290 kPa

Tstd = 293.15 K

0.1651 299.5 101.3

20.085 98.290 293.15

Vrev

 



 

Vrev = 0.00866 m3/r

(2) Calculate a PDP slip correction factor, Ks for each restrictor position from the mean 

values determined in § 1066.140:

out in

s

nPDP out

1 p p K

f p



 

Eq. 1066.625-2

Where:

nPDP f = mean PDP speed.

out p = mean static absolute pressure at the PDP outlet.

in p = mean static absolute pressure at the PDP inlet.

Example:

nPDP f = 1205.1 r/min = 20.085 r/s

out p = 100.103 kPa

in p = 98.290 kPa
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 991 of 1039

s

1 100.103 98.290

20.085 100.103

K



 

Ks = 0.006700 s/r

(3) Perform a least-squares regression of Vrev, versus Ks, by calculating slope, a1, and 

intercept, a0, as described in 40 CFR 1065.602.

(4) Repeat the procedure in paragraphs (a)(1) through (3) of this section for every speed 

that you run your PDP.

(5) The following example illustrates a range of typical values for different PDP speeds:

TABLE 1 OF § 1066.625–

EXAMPLE OF PDP CALIBRATION DATA

nPDP f

(revolution/s)

a1 

(m3/s)

a0 

(m3/revolution)

12.6 0.841 0.056

16.5 0.831 -0.013

20.9 0.809 0.028

23.4 0.788 -0.061

(6) For each speed at which you operate the PDP, use the appropriate regression equation 

from this paragraph (a) to calculate flow rate during emission testing as described in § 

1066.630.

(b) SSV calibration. The equations governing SSV flow assume one-dimensional 

isentropic inviscid flow of an ideal gas, except that the equations can account for 

compressible flow. Paragraph (b)(2)(iv) of this section describes other assumptions that 

may apply. If good engineering judgment dictates that you account for gas 

compressibility, you may either use an appropriate equation of state to determine values 

of Z as a function of measured pressure and temperature, or you may develop your own 

calibration equations based on good engineering judgment. Note that the equation for the 

flow coefficient, Cf, is based on the ideal gas assumption that the isentropic exponent, , 

is equal to the ratio of specific heats, Cp/Cv. If good engineering judgment dictates using 

a real gas isentropic exponent, you may either use an appropriate equation of state to 

determine values of  as a function of measured pressure and temperature, or you may

develop your own calibration equations based on good engineering judgment.

(1) Calculate volume flow rate, Q, as follows

t in std

d f

std mix in

A R p T Q C C

p Z M R T

  

  

   



Eq. 1066.625-3

Where:

Cd = discharge coefficient, as determined in paragraph (b)(2)(i) of this section.

Cf = flow coefficient, as determined in paragraph (b)(2)(ii) of this section.

At = cross-sectional area at the venturi throat.

R = molar gas constant.

pin = static absolute pressure at the venturi inlet.
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 992 of 1039

Tstd = standard temperature.

pstd = standard pressure.

Z = compressibility factor.

Mmix = molar mass of gas mixture.

Tin = absolute temperature at the venturi inlet.

(2) Perform the following steps to calibrate an SSV flow meter:

(i) Using the data collected in § 1066.140, calculate Cd for each flow rate using the 

following equation:

std mix in

d ref

f t in std

p Z M R T

C Q

C A R p T

   

 

   



Eq. 1066.625-4

Where: 

Qref

 = measured volume flow rate from the reference flow meter.

(ii) Use the following equation to calculate Cf for each flow rate:

 

   

1

2

1

2

f

4

2 1

1

r

C

r









 





 

  

 



  

 

Eq. 1066.625-5

Where:

 = isentropic exponent. For an ideal gas, this is the ratio of specific heats of the gas 

mixture, Cp/Cv.

r = pressure ratio, as determined in paragraph (b)(2)(iii) of this section.

 = ratio of venturi throat diameter to inlet diameter.

(iii) Calculate r using the following equation:

in

1

p

r

p



 

Eq. 1066.625-6

Where:

Δp = differential static pressure, calculated as venturi inlet pressure minus venturi throat 

pressure.

(iv) You may apply any of the following simplifying assumptions or develop other values 

as appropriate for your test configuration, consistent with good engineering judgment:

(A) For raw exhaust, diluted exhaust, and dilution air, you may assume that the gas 

mixture is incompressible and therefore behaves as an ideal gas (Z=1).

(B) For raw exhaust, you may assume =1.385.

(C) For diluted exhaust and dilution air, you may assume =1.399.

(D) For diluted exhaust and dilution air, you may assume Mmix is a function only of the 

amount of water in the dilution air or calibration air, as follows:
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Page 993 of 1039

  mix 2

air H2O H O H2O M M  1  x M  x

Eq. 1066.625-7

Where:

Mair = 28.96559 g/mol

xH2O = amount of H2O in the dilution air or calibration air, determined as described in 40 

CFR 1065.645.

MH2O = 18.01528 g/mol

Example:

xH2O = 0.0169 mol/mol

Mmix   28.96559 1 0   .0169 18.015280.0169

Mmix = 28.7805 g/mol

(E) For diluted exhaust and dilution air, you may assume a constant molar mass of the 

mixture, Mmix, for all calibration and all testing if you control the amount of water in 

dilution air and in calibration air, as illustrated in the following table:

TABLE 2 OF § 1066.625–

EXAMPLES OF DILUTION AIR AND CALIBRATION AIR 

DEWPOINTS AT WHICH YOU MAY ASSUME A CONSTANT MMIX

If calibration 

Tdew (C) is...

assume the following 

constant Mmix (g/mol)...

for the following ranges of Tdew

(C) during emission testsa

< 0 28.96559 < 18

0 28.89263 < 21

5 28.86148 < 22

10 28.81911 < 24

15 28.76224 < 26

20 28.68685 -8 to 28

25 28.58806 12 to 31

30 28.46005 23 to 34

aThe specified ranges are valid for all calibration and emission testing over the 

atmospheric pressure range (80.000 to 103.325) kPa.

(v) The following example illustrates the use of the governing equations to calculate Cd

of an SSV flow meter at one reference flow meter value:

Example:

Qref

 = 2.395 m3

/s

Z = 1

Mmix = 28.7805 g/mol = 0.0287805 kg/mol

R = 8.314472 J/(mol∙K) = 8.314472 (m2∙kg)/(s2∙mol∙K)

Tin = 298.15 K

At = 0.01824 m2
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 994 of 1039

pin = 99.132 kPa = 99132 Pa = 99132 kg/(m∙s2)

 = 1.399

 = 0.8

Δp = 7.653 kPa

2.312 1 0.922

99.132

r   

 

   

1.399 1

1.399

2

1.399

1

2

f

4

2 1.399 0.922 1

1.399 1 0.8 0.922

C





    

  

  

 

Cf = 0.472

d

101325 1 0.0287805 8.314472 298.15 2.395

0.472 0.01824 8.314472 99132 293.15

C

   

 

   

Cd = 0.985

(vi) Calculate the Reynolds number, Re#, for each reference flow rate, Qref



, using the 

throat diameter of the venturi, dt, and the uncorrected air density, . Because the 

dynamic viscosity, μ, is needed to compute Re#, you may use your own fluid viscosity

model to determine μ for your calibration gas (usually air), using good engineering 

judgment. Alternatively, you may use the Sutherland three-coefficient viscosity model to 

approximate μ, as shown in the following sample calculation for Re#:

# ref

t

4 Q

Re =

d



 

 

 



Eq. 1066.625-8

Where, using the Sutherland three-coefficient viscosity model:

3

2

in 0

0

0 in

T T S

T T S

 

    

           

Eq. 1066.625-9

Where:

0 = Sutherland reference viscosity.

T0 = Sutherland reference temperature.

S = Sutherland constant.
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 995 of 1039

TABLE 3 OF § 1065.640–

SUTHERLAND THREE-COEFFICIENT VISCOSITY MODEL PARAMETERS

Gasa μ0 T0 S

Temperature 

range within ±2 

% errorb

Pressure 

limitb

kg/(m∙s) K K K kPa

Air 1.716∙10-5273 111 170 to 1900 ≤ 1800

CO2 1.370∙10-5273 222 190 to 1700 ≤ 3600

H2O 1.12∙10-5350 1064 360 to 1500 ≤ 10000 

O2 1.919∙10-5273 139 190 to 2000 ≤ 2500

N2 1.663∙10-5273 107 100 to 1500 ≤ 1600

aUse tabulated parameters only for the pure gases, as listed. Do not combine 

parameters in calculations to calculate viscosities of gas mixtures.

bThe model results are valid only for ambient conditions in the specified ranges.

Example:

μ0 = 1.716∙10-5kg/(m∙s)

T0 = 273 K

S = 111 K

3

2

5 298.15 273 111 1.716 10

273 298.15 111



     

            

μ = 1.838∙10-5kg/(m∙s)

Tin = 298.15 K

dt = 152.4 mm = 0.1524 m

 = 1.1509 kg/m3

#

5

4 1.1509 2.395

3.14159 0.1524 1.838 10

Re = 

 

  

Re#= 1.2531∙106

(vii) Calculate ρ using the following equation:

in mix

in

p MW

R T









Eq. 1066.625-10

Example:

99132 0.0287805

8.314472 298.15









ρ = 1.1509 kg/m3

(viii) Create an equation for Cd as a function of Re#, using paired values of the two 

quantities. The equation may involve any mathematical expression, including a 

polynomial or a power series. The following equation is an example of a commonly used 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 996 of 1039

mathematical expression for relating Cd and Re#:

6

d 0 1 #

10 C a a

Re

  

Eq. 1066.625-11

(ix) Perform a least-squares regression analysis to determine the best-fit coefficients for 

the equation and calculate SEE as described in 40 CFR 1065.602.

(x) If the equation meets the criterion of SEE ≤ 0.5 %, you may use the equation for the 

corresponding range of Re#, as described in § 1066.652.

(xi) If the equation does not meet the specified statistical criteria, you may use good 

engineering judgment to omit calibration data points; however, you must use at least 

seven calibration data points to demonstrate that you meet the criterion. For example, 

this may involve narrowing the range of flow rates for a better curve fit.

(xii) Take corrective action if the equation does not meet the specified statistical criterion 

even after omitting calibration data points. For example, select another mathematical 

expression for the Cd versus Re#equation, check for leaks, or repeat the calibration 

process. If you must repeat the calibration process, we recommend applying tighter 

tolerances to measurements and allowing more time for flows to stabilize.

(xiii) Once you have an equation that meets the specified statistical criterion, you may

use the equation only for the corresponding range of flow rates.

(c) CFV calibration. Some CFV flow meters consist of a single venturi and some consist 

of multiple venturis where different combinations of venturis are used to meter different 

flow rates. For CFV flow meters that consist of multiple venturis, either calibrate each 

venturi independently to determine a separate calibration coefficient, Kv, for each venturi, 

or calibrate each combination of venturis as one venturi by determining Kv for the 

system.

(1) To determine Kv for a single venturi or a combination of venturis, perform the 

following steps:

(i) Calculate an individual Kv for each calibration set point for each restrictor position 

using the following equation:

refstd in

v

in

Q T

K =

p





Eq. 1066.625-12

Where:

Qrefstd

 = mean flow rate from the reference flow meter, corrected to standard reference 

conditions.

Tin = mean temperature at the venturi inlet.

in p = mean static absolute pressure at the venturi inlet.

(ii) Calculate the mean and standard deviation of all the Kv values (see 40 CFR 

1065.602). Verify choked flow by plotting Kv as a function of in p . Kv will have a 

relatively constant value for choked flow; as vacuum pressure increases, the venturi will 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 997 of 1039

become unchoked and Kv will decrease. Paragraphs (c)(1)(iii) through (viii) of this 

section describe how to verify your range of choked flow.

(iii) If the standard deviation of all the Kv values is less than or equal to 0.3 % of the 

mean Kv, use the mean Kv in Eq. 1066.630-7, and use the CFV only up to the highest 

venturi pressure ratio, r, measured during calibration using the following equation:

CFV

in

1

p

r

p



 

Eq. 1066.625-13

Where:

pCFV = differential static pressure; venturi inlet minus venturi outlet.

(iv) If the standard deviation of all the Kv values exceeds 0.3 % of the mean Kv, omit the 

Kv value corresponding to the data point collected at the highest r measured during 

calibration.

(v) If the number of remaining data points is less than seven, take corrective action by 

checking your calibration data or repeating the calibration process. If you repeat the 

calibration process, we recommend checking for leaks, applying tighter tolerances to 

measurements and allowing more time for flows to stabilize.

(vi) If the number of remaining Kv values is seven or greater, recalculate the mean and 

standard deviation of the remaining Kv values.

(vii) If the standard deviation of the remaining Kv values is less than or equal to 0.3 % of 

the mean of the remaining Kv, use that mean Kv in Eq 1066.630-7, and use the CFV 

values only up to the highest r associated with the remaining Kv.

(viii) If the standard deviation of the remaining Kv still exceeds 0.3 % of the mean of the 

remaining Kv values, repeat the steps in paragraph (c)(1)(iv) through (vii) of this section.

(2) During exhaust emission tests, monitor sonic flow in the CFV by monitoring r. Based 

on the calibration data selected to meet the standard deviation criterion in paragraphs 

(c)(1)(iv) and (vii) of this section, in which Kv is constant, select the data values 

associated with the calibration point with the lowest absolute venturi inlet pressure to 

determine the r limit. Calculate r during the exhaust emission test using Eq. 1066.625-8 

to demonstrate that the value of r during all emission tests is less than or equal to the r

limit derived from the CFV calibration data.

§ 1066.630 PDP, SSV, and CFV flow rate calculations.

This section describes the equations for calculating flow rates from various flow meters. 

After you calibrate a flow meter according to § 1066.625, use the calculations described 

in this section to calculate flow during an emission test. Calculate flow according to 40

CFR 1065.642 instead if you calculate emissions based on molar flow rates.

(a) PDP. (1) Based on the speed at which you operate the PDP for a test interval, select 

the corresponding slope, a1, and intercept, a0, as determined in § 1066.625(a), to calculate 

PDP flow rate, Q, as follows:

rev std in

nPDP

in std

V T p

Q f

T p

 

 




*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 998 of 1039

Eq. 1066.630-1

Where:

fnPDP = pump speed.

Vrev = PDP volume pumped per revolution, as determined in paragraph (a)(2) of this 

section.

Tstd = standard temperature = 293.15 K.

pin = static absolute pressure at the PDP inlet.

Tin = absolute temperature at the PDP inlet.

pstd = standard pressure= 101.325 kPa.

(2) Calculate Vrev using the following equation:

1 out in

rev 0

nPDP out

a p p V a

f p



  

Eq. 1066.630-2

pout = static absolute pressure at the PDP outlet.

Example:

a1 = 50.43 m3/min = 0.8405 m3/s

fnPDP = 755.0 r/min = 12.58 r/s

pout = 99.950 kPa

pin = 98.575 kPa 

a0 = 0.056 m3/r

Tin = 323.5 K

rev

0.8405 99.950 98.575 0.056

12.58 99.950

V



  

Vrev = 0.063 m3/r

0.06383 293.15 98.575 12.58

323.5 101.3

Q

 

 





Q = 0.7079 m3

/s

(b) SSV. Calculate SSV flow rate, Q, as follows: 

t in std

d f

std mix in

A R p T Q C C

p Z M R T

  

  

   



Eq. 1066.630-3

Where:

Cd = discharge coefficient, as determined based on the Cd versus Re#equation in § 

1066.625(b)(2)(viii).

Cf = flow coefficient, as determined in § 1066.625(b)(2)(ii).

At = venturi throat cross-sectional area.

R = molar gas constant.

pin = static absolute pressure at the venturi inlet.

Tstd = standard temperature.
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 999 of 1039

pstd = standard pressure.

Z = compressibility factor.

Mmix = molar mass of gas mixture.

Tin = absolute temperature at the venturi inlet.

Example: 

Cd = 0.890

Cf = 0.472

At = 0.01824 m2

R = 8.314472 J/(mol∙K) = 8.314472 (m2∙kg)/(s2∙mol∙K)

pin = 98.496 kPa

Tstd = 293.15 K

pstd = 101.325 kPa

Z = 1

Mmix = 28.7789 g/mol = 0.0287789 kg/mol

Tin = 296.85 K

0.01824 8.314472 98.496 293.15 0.89 0.472

101.325 1 0.0287805 8.314472 296.85

Q

  

  

   



Q = 2.155 m3

/s

(c) CFV. If you use multiple venturis and you calibrated each venturi independently to 

determine a separate calibration coefficient, Kv, for each venturi, calculate the individual 

volume flow rates through each venturi and sum all their flow rates to determine CFV 

flow rate, Q. If you use multiple venturis and you calibrated venturis in combination, 

calculate Q using the Kv that was determined for that combination of venturis.

(1) To calculate Qthrough one venturi or a combination of venturis, use the mean Kv

you determined in § 1066.625(c) and calculate the appropriate quantity for Q as follows:

v in

in

K p Q =

T





Eq. 1066.630-7

Where:

Kv = flow meter calibration coefficient.

Tin = temperature at the venturi inlet.

pin = absolute static pressure at the venturi inlet.

Example: 

Kv = 0.074954 m3∙K0.5/(kPa∙s)

pin = 99.654 kPa

Tin = 353.15 K

0.074954 99.654

353.15

Q







Q = 0.39748 m3

/s
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 1000 of 1039

(2) [Reserved]

§ 1066.635 NMOG determination.

For vehicles subject to an NMOG standard, determine NMOG as described in paragraph 

(a) of this section. Except as specified in the standard-setting part, you may alternatively 

calculate NMOG results based on measured NMHC emissions as described in paragraphs 

(c) through (f) of this section.

(a) Determine NMOG by independently measuring alcohols and carbonyls as described 

in 40 CFR 1065.805 and 1065.845. Use good engineering judgment to determine which 

alcohols and carbonyls you need to measure. This would typically require you to 

measure all alcohols and carbonyls that you expect to contribute 1% or more of total 

NMOG. Calculate the mass of NMOG in the exhaust, mNMOG, with the following 

equation, using density values specified in § 1066.1005(f):

OHCi

NMOG NMHC NMHC OHCi[THC-FID] OHCi

1 1 OHCi

N N

i i

m

m m  RF m

  

     

Eq. 1066.635-1

Where:

mNMHC = the mass of NMHC and all oxygenated hydrocarbons (OHCs) in the exhaust, as 

determined using Eq. 1066.605-1. Calculate NMHC mass based on ρNMHC.

ρNMHC = the effective C1-equivalent density of NMHC as specified in § 1066.1005(f).

mOHCi = the mass of oxygenated species i in the exhaust calculated using Eq. 1066.605-1.

ρOCHi = the C1-equivalent density of oxygenated species i.

RFOHCi[THC-FID] = the response factor of a THC-FID to oxygenated species i relative to 

propane on a C1-equivalent basis as determined in 40 CFR 1065.845.

(b) The following example shows how to determine NMOG as described in paragraph (a) 

of this section for (OHC) compounds including ethanol (C2H5OH), methanol (CH3OH), 

acetaldehyde (C2H4O), and formaldehyde (CH2O) as C1-equivalent concentrations:

mNMHC = 0.0125 g

mCH3OH = 0.0002 g

mC2H5OH = 0.0009 g

mCH2O = 0.0001 g

mC2H4O = 0.00005 g

RFCH3OH[THC-FID] = 0.63

RFC2H5OH[THC-FID] = 0.75

RFCH2O[THC-FID] = 0.00

RFC2H4O[THC-FID] = 0.50

ρNMHC-liq = 576.816 g/m3

ρCH3OH = 1332.02 g/m3

ρC2H5OH = 957.559 g/m3

ρCH2O = 1248.21 g/m3

ρC2H4O = 915.658 g/m3
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 1001 of 1039

NMOG

0.0002 0.0009 0.63 0.75

1332.02 957.559 0.0125 576.816

0.0001 0.00005 0.00 0.5

1248.21 915.658

0.0002 0.0009 0.0001 0.00005

m

 

     

   

  

 

  

mNMOG = 0.013273

(c) For ethanol-gasoline blends with less than 25 % ethanol by volume, you may

calculate NMOG from measured NMHC emissions as follows:

(1) For hot-start and hot-running test cycles or intervals other than the FTP, you may

determine NMOG based on the NMHC emission rate using the following equation:

NMOGh NMHCh e e  1.03

Eq. 1066.635-2

Where:

eNMOGh = mass emission rate of NMOG from the hot-running test cycle.

eNMHCh = mass emission rate of NMHC from the hot-running test cycle, calculated using

ρNMHC-liq.

Example:

eNMHCh = 0.025 g/mi

NMOGh e   0.025 1.03  0.026 g/mi

(2) You may determine weighted composite NMOG for FTP testing based on the 

weighted composite NMHC emission rate and the volume percent of ethanol in the fuel 

using the following equation:

e e NMOGcomp   NMHCcomp 1.0302   0.0071 VPEtOH 

Eq. 1066.635-3

Where:

eNMOGcomp = weighted FTP composite mass emission rate of NMOG.

eNMHCcomp = weighted FTP composite mass emission rate of NMHC, calculated using

ρNMHC-liq.

VPEtOH = volume percentage of ethanol in the test fuel. Use good engineering judgment 

to determine this value either as specified in 40 CFR 1065.710 or based on blending 

volumes, taking into account any denaturant.

Example:

eNMHCcomp = 0.025 g/mi

VPEtOH = 10.1 %

eNMOGcomp   0.025 1.0302   0.0071 10.1  0.0275 g/mi

(3) You may determine NMOG for the transient portion of the FTP cold-start test for use 

in fuel economy and CREE calculations based on the NMHC emission rate for the test 

interval and the volume percent of ethanol in the fuel using the following equation:
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 1002 of 1039

e e NMOG-FTPct   NMHC-FTPct 1.0246   0.0079 VPEtOH 

Eq. 1066.635-4

Where:

eNMOG-FTPct = mass emission rate of NMOG from the transient portion of the FTP coldstart test (generally known as bag 1).

eNMHC-FTPct = mass emission rate of NMHC from the transient portion of the FTP coldstart test (bag 1), calculated using ρNMHC-liq.

Example:

eNMHC-FTPct = 0.052 g/mi

VPEtOH = 10.1 %

eNMOG-FTPct   0.052 1.0246   0.0079 10.1  0.0574 g/mi

(4) You may determine NMOG for the stabilized portion of the FTP test for either the 

cold-start test or the hot-start test (bag 2 or bag 4) for use in fuel economy and CREE 

calculations based on the corresponding NMHC emission rate and the volume percent of 

ethanol in the fuel using the following equation:

e e NMOG-FTPcs-hs   NMHC-FTPcs-hs 1.1135  0.001 VPEtOH 

Eq. 1066.635-5

Where:

eNMOG-FTPcs-hs = mass emission rate of NMOG from the stabilized portion of the FTP test 

(bag 2 or bag 4).

eNMHC-FTPcs-hs = mass emission rate of NMHC from the stabilized portion of the FTP test 

(bag 2 or bag 4), calculated using ρNMHC-liq.

(5) You may determine NMOG for the transient portion of the FTP hot-start test for use 

in fuel economy and CREE calculations based on the NMHC emission rate for the test 

interval and the volume percent of ethanol in the fuel using the following equation:

e e NMOG-FTPht   NMHC-FTPht 1.0195   0.0031 VPEtOH 

Eq. 1066.635-6

Where:

eNMOG-FTPht = mass emission rate of NMOG from the transient portion of the FTP hot-start 

test (bag 3).

eNMHC-FTPht = mass emission rate of NMHC from the transient portion of the FTP hot-start 

test (bag 3), calculated using ρNMHC-liq.

(d) You may take the following alternative steps when determining fuel economy and 

CREE under 40 CFR part 600 for testing with ethanol-gasoline blends that have up to 25 

% ethanol by volume:

(1) Calculate NMOG by test interval using Eq. 1066.635-3 for individual bag 

measurements from the FTP.

(2) For HEVs, calculate NMOG for two-bag FTPs using Eq. 1066.635-3 as described in 

40 CFR 600.114.
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 1003 of 1039

(e) We consider NMOG values for diesel-fueled vehicles, CNG-fueled vehicles, LNGfueled vehicles, and LPG-fueled vehicles to be equivalent to NMHC emission values for 

all test cycles.

(f) For all fuels not covered by paragraphs (c) and (e) of this section, manufacturers may

propose a methodology to calculate NMOG results from measured NMHC emissions. 

We will approve adjustments based on comparative testing that demonstrates how to 

properly represent NMOG based on measured NMHC emissions.

§ 1066.695 Data requirements.

Record information for each test as follows:

(a) Test number.

(b) A brief description of the test vehicle (or other system/device tested).

(c) Date and time of day for each part of the test sequence.

(d) Test results. Also include a validation of driver accuracy as described in § 

1066.425(j).

(e) Driver and equipment operators.

(f) Vehicle information as applicable, including identification number, model year, 

applicable emission standards(including bin standards or family emission limits, as 

applicable), vehicle model, vehicle class, test group, durability group, engine family, 

evaporative/refueling emission family, basic engine description (including displacement, 

number of cylinders, turbocharger/supercharger used, and catalyst type), fuel system 

(type of fuel injection and fuel tank capacity and location), engine code, GVWR, 

applicable test weight, inertia weight class, actual curb weight at zero miles, actual road 

load at 50 mph, transmission class and configuration, axle ratio, odometer reading, idle 

rpm, and measured drive wheel tire pressure.

(g) Dynamometer identification, inertia weight setting, indicated power absorption 

setting, and records to verify compliance with the driving distance and cycle-validation 

criteria as calculated from measured roll or shaft revolutions.

(h) Analyzer bench identification, analyzer ranges, recordings of analyzer output during 

zero, span, and sample readings.

(i) Associate the following information with the test record: test number, date, vehicle 

identification, vehicle and equipment operators, and identification of the measurements 

recorded.

(j) Test cell barometric pressure and humidity. You may use a central laboratory

barometer if the barometric pressure in each test cell is shown to be within ±0.1 % of the 

barometric pressure at the central barometer location.

(k) Records to verify compliance with the ambient temperature requirements throughout 

the test procedure and records of fuel temperatures during the running loss test.

(l) [Reserved]

(m) For CVS systems, record dilution factor for each test interval and the following 

additional information:

(1) For CFV and SSV testing, Vmix for each interval of the exhaust test.

(2) For PDP testing, test measurements required to calculate Vmix for each test interval.
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 1004 of 1039

(n) The humidity of the dilution air, if you remove H2O from an emission sample before 

measurement.

(o) Temperature of the dilute exhaust mixture and secondary dilution air (in the case of a 

double-dilution system) at the inlet to the respective gas meter or flow instrumentation 

used for PM sampling. Determine minimum values, maximum values, mean values, and 

percent of time outside of the tolerance over each test interval.

(p) The maximum exhaust gas temperature over the course of the test interval within 20 

cm upstream or downstream of PM sample media.

(q) If applicable, the temperatures of the heated FID, the gas in the heated sample line, 

and the heated filter. Determine minimum values, maximum values, average values, and 

percent of time outside of the tolerance over each test interval.

(r) Gas meter or flow measurement instrumentation readings used for batch sampling 

over each test interval. Determine minimum, maximum, and average values over each 

test interval.

(s) The stabilized pre-test weight and post-test weight of each particulate sample media 

(e.g., filter).

(t) Continuous temperature and humidity of the ambient air in which the PM sample 

media are stabilized. Determine minimum values, maximum values, average values, and 

percent of time outside of the tolerance over each test interval.

(u) For vehicles fueled by natural gas, the test fuel composition, including all carboncontaining compounds (including CO2, but excluding CO). Record C1 and C2

compounds individually. You may record C3 through C5 hydrocarbons together, and you 

may record C6 and heavier hydrocarbon compounds together.

(v) For vehicles fueled by liquefied petroleum gas, the test fuel composition, including all 

carbon-containing compounds (including CO2, but excluding CO). Record C1 through C4

compounds individually. You may record C5 and heavier hydrocarbons together.

(w) For the AC17 test in § 1066.845, interior volume, climate control system type and 

characteristics, refrigerant used, compressor type, and evaporator/condenser 

characteristics.

(x) Additional information related to evaporative emissions. [Reserved]

(y) Additional information related to refueling emissions. [Reserved]

Subpart H—COLD TEMPERATURE TEST PROCEDURES

§ 1066.701 Applicability and general provisions.

(a) The procedures of this part 1066 may be used for testing at any ambient temperature. 

Section 1066.710 describes the provisions that apply for testing vehicles at a nominal 

temperature of 20 °C (68 °F); these procedures apply for motor vehicles as described in 

40 CFR part 86, subpart S, and 40 CFR part 600. For other vehicles, see the standardsetting part to determine if your vehicle is required to meet emission standards outside the 

normal (20 to 30) °C ((68 to 86) °F) temperature range.

(b) Do not apply the humidity correction factor in § 1066.615(a) for cold temperature 

testing.
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 1005 of 1039

§ 1066.710 Cold temperature testing procedures for measuring CO and NMHC 

emissions and determining fuel economy.

This section describes procedures for measuring carbon monoxide (CO) and nonmethane 

hydrocarbon (NMHC) emissions and determining fuel economy on a cold day using the

FTP test cycle (see § 1066.801). The following figure illustrates the test procedure:
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 1006 of 1039

Figure 1 of § 1066.710— Cold temperature testing sequence for measuring CO and NMHC emissions and determining fuel 

economy
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 1007 of 1039
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

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(a) Follow the exhaust emission measurement procedures specified in §§ 1066.410 

through 1066.425 and § 1066.815(d), subject to the following exceptions and additional 

provisions:

(1) Measure and control ambient conditions as specified in paragraph (b) of this section.

(2) Use the vehicle’s heater and defroster as specified in paragraph (c) of this section.

(3) Precondition and stabilize the vehicle as specified in paragraphs (d) and (e) of this 

section. Ensure that there is no precipitation or dew on the vehicle before the emission 

test.

(4) For dynamometers that have independently heated bearings, start the emission test 

within 20 minutes after warming up the dynamometer; for other types of dynamometers, 

start the emission test within 10 minutes after warming up the dynamometer.

(5) Adjust the dynamometer to simulate vehicle operation on the road at −7 °C. Base this 

adjustment on the road-load force profile at −7 °C, or on a 10 percent decrease in the 

target coastdown time used for FTP testing.

(6) Analyze samples for NMHC, CO, and CO2. You do not need to analyze samples for 

other pollutants.

(b) Maintain ambient conditions as follows instead of following the specifications in 

subpart E of this part:

(1) Ambient temperature for emission tests. Measure and record ambient temperature in 

the test cell at least once every 60 seconds during the sampling period. The temperature 

must be (−7.0 ±1.7) °C at the start of the test and average temperature must be (−7.0 

±2.8) °C during the test. Instantaneous temperature values may be above −4.0 °C or 

below −9.0 °C, but not for more than 3 minutes at a time during the test.

(2) Ambient temperature for preconditioning. Instantaneous ambient temperature values 

may be above −4.0 °C or below −9.0 °C but not for more than 3 minutes at a time during 

the preconditioning period. At no time may the ambient temperatures be below −12.0 °C

or above −1.0 °C. The average ambient temperature during preconditioning must be 

(−7.0 ±2.8) °C. You may precondition vehicles at temperatures above −7.0 °C or with a 

temperature tolerance greater than that described in this section (or both) if you determine 

that this will not cause NMHC, CO, or CO2 emissions to decrease; if you modify the 

temperature specifications for vehicle preconditioning, adjust the procedures described in 

this section appropriately for your testing.

(3) Ambient humidity. Maintain humidity low enough to prevent condensation on the 

dynamometer rolls during testing.

(c) Heater and defroster. During the test, operate the vehicle’s interior climate control 

system with the heat on and set to primarily defrost the front window. Turn air 

conditioning off. You may not use any supplemental auxiliary heat during this testing. 

You may set the heater to any temperature and fan setting during vehicle preconditioning. 

(1) Manually controlled systems. (i) Prior to the first acceleration, 20 seconds after the 

start of the UDDS, set the climate control as follows (these settings may be initiated prior 

to starting the vehicle if allowed by the vehicle’s climate control system):

(A) Temperature. Set controls to maximum heat.

(B) Fan speed. Set the fan speed to full off or the lowest available speed if a full off 

position is not available.
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(C) Airflow direction. Direct airflow to the front window (window defrost mode).

(D) Air source. If independently controllable, set the system to draw in outside air.

(ii) At the second idle of the test cycle, which occurs 125 seconds after the start of the 

test, set the fan speed to maximum. Complete by 130 seconds after the start of the test. 

Leave temperature and air source settings unchanged

(iii) At the sixth idle of the test interval, which occurs at the deceleration to zero miles per 

hour 505 seconds after the start of the test, set the fan speed to the lowest setting that 

maintains air flow. Complete these changes by 510 seconds after the start of the test. 

You may use different vent and fan speed settings for the remainder of the test. Leave 

the temperature and air source settings unchanged.

(2) Automatic control systems. For vehicles with automatic control systems, you may

follow the provisions of paragraph (c)(1) of this section or you may set the temperature to 

72 °F and the air flow control to the front window defrost mode for the whole test.

(3) Multiple-zone systems. For vehicles that have separate driver and passenger controls 

or separate front and rear controls, you must set all temperature and fan controls as 

described in paragraphs (c)(1) and (2) of this section, except that rear controls need not be 

set to defrost the front window.

(4) Alternative test procedures. We may approve the use of other settings under 40 CFR 

86.1840 if a vehicle’s climate control system is not compatible with the provisions of this 

section.

(d) Take the following steps to prepare and precondition vehicles for testing under this 

section:

(1) Prepare the vehicle as described in § 1066.810(a). 

(2) Fill the fuel tank to approximately 40 % of the manufacturer’s nominal fuel tank 

capacity with the appropriate test fuel for cold temperature testing as specified 40 CFR 

part 1065, subpart H. The temperature of the dispensed test fuel must be at or below 15.5 

°C. If the leftover fuel in the fuel tank before the refueling event does not meet these 

specifications, drain the fuel tank before refueling. You may operate the vehicle prior to 

the preconditioning drive to eliminate fuel effects on adaptive memory systems.

(3) You may start the preconditioning drive once the fuel in the fuel tank reaches (12.6 to 

-1.4) °C. Precondition the vehicle as follows:

(i) Push or drive the vehicle onto the dynamometer.

(ii) Operate the vehicle over one UDDS. You may perform additional vehicle 

preconditioning with repeated driving over the UDDS, subject to our advance approval. 

(iii) Turn off the test vehicle and any cooling fans within 5 minutes after completing the 

preconditioning drive. Ambient temperature must be between (−12.0 and −1.0) °C in the 

5 minutes following the preconditioning drive.

(iv) Do not manually purge or load the evaporative canister.

(e) Soak the vehicle for (12 to 36) hours to stabilize it at test temperatures before starting 

the emission test as described in this paragraph (e). If you move a stabilized vehicle 

through a warm area when transporting it to the dynamometer for testing, you must 

restabilize the vehicle by holding it at an ambient temperature within the range specified 

in paragraph (b)(1) of this section for at least six times as long as the vehicle was exposed 
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to warmer temperatures. Use one of the following methods to reach a stabilized 

condition:

(1) Cold storage. Measure and record ambient temperature in the test cell at least once 

every 60 seconds during the ambient cold soak period. These ambient temperatures may

be above −4.0 °C or below −9.0 °C, but not for more than 3 minutes at a time. Use 

measured values to calculate an hourly average temperature. Each hourly average 

temperature must be (−7.0 °C ±2.8) °C.

(2) Forced-cooling or warming. Position fans to blow temperature-controlled air onto the 

vehicle to stabilize the vehicle at the specified temperatures for emission testing. Position 

fans to target the vehicle’s drive train, engine block, and radiator rather than the oil pan. 

You may not place fans under the vehicle. You may consider the vehicle to be stabilized 

at the test temperature when the bulk oil temperature reaches (-8.7 to -5.3) °C; measure

oil temperature at one or more points away from the side or bottom surfaces of the oil 

pan. Each oil temperature measurement must be within the specified range before 

stabilization is complete. Once the vehicle reaches this stabilized condition, cold soak 

the vehicle within the stabilized temperature range for at least one hour before starting the 

emission test. During this time, keep the ambient temperature within the range specified 

in paragraph (b)(1) of this section.

Subpart I—EXHAUST EMISSION TEST PROCEDURES FOR MOTOR

VEHICLES

§ 1066.801 Applicability and general provisions.

This subpart I specifies how to apply the test procedures of this part for light-duty

vehicles, light-duty trucks, and heavy-duty vehicles at or below 14,000 pounds GVWR 

that are subject to chassis testing for exhaust emissions under 40 CFR part 86, subpart S. 

For these vehicles, references in this part 1066 to the standard-setting part include this 

subpart I.

(a) Use the procedures detailed in this subpart to measure vehicle emissions over a 

specified drive schedule in conjunction with subpart E of this part. Where the procedures 

of subpart E of this part differ from this subpart I, the provisions in this subpart I take 

precedence.

(b) Collect samples of every pollutant for which an emission standard applies, unless 

specified otherwise.

(c) This subpart covers the following test procedures:

(1) The Federal Test Procedure (FTP), which includes the general driving cycle. This 

procedure is also used for measuring evaporative emissions. This may be called the 

conventional test since it was adopted with the earliest emission standards.

(i) The FTP consists of one Urban Dynamometer Driving Schedule (UDDS) as specified 

in paragraph (a) of Appendix I of 40 CFR part 86, followed by a 10-minute soak with the 

engine off and repeat driving through the first 505 seconds of the UDDS. Note that the 

UDDS represents about 7.5 miles of driving in an urban area. Engine startup (with all 

accessories turned off), operation over the initial UDDS, and engine shutdown make a 

complete cold-start test. The hot-start test consists of the first 505 seconds of the UDDS 
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following the 10-minute soak and a hot-running portion of the UDDS after the first 505 

seconds. The first 505 seconds of the UDDS is considered the transient portion; the 

remainder of the UDDS is considered the stabilized (or hot-stabilized) portion. The hotstabilized portion for the hot-start test is generally measured during the cold-start test; 

however, in certain cases, the hot-start test may involve a second full UDDS following 

the 10-minute soak, rather than repeating only the first 505 seconds. See §§ 1066.815 

and 1066.820.

(ii) Evaporative emission testing includes a preconditioning drive with the UDDS and a 

full FTP cycle, including exhaust measurement, followed by evaporative emission 

measurements. In the three-day diurnal test sequence, the exhaust test is followed by a

running loss test consisting of a UDDS, then two New York City Cycles as specified in 

paragraph (e) of Appendix I of 40 CFR part 86, followed by another UDDS; see 40 CFR 

86.134. Note that the New York City Cycle represents about 1.18 miles of driving in a 

city center. The running loss test is followed by a high-temperature hot soak test as 

described in 40 CFR 86.138 and a three-day diurnal emission test as described in 40 CFR 

86.133. In the two-day diurnal test sequence, the exhaust test is followed by a lowtemperature hot soak test as described in 40 CFR 86.138-96(k) and a two-day diurnal 

emission test as described in 40 CFR 86.133-96(p). 

(iii) Refueling emission tests for vehicles that rely on integrated control of diurnal and 

refueling emissions includes vehicle operation over the full FTP test cycle corresponding 

to the three-day diurnal test sequence to precondition and purge the evaporative canister. 

For non-integrated systems, there is a preconditioning drive over the UDDS and a 

refueling event, followed by repeated UDDS driving to purge the evaporative canister. 

The refueling emission test procedures are described in 40 CFR 86.150 through 86.157.

(2) The Supplemental Federal Test Procedure (SFTP) measures the emission effects from 

aggressive driving and operation with the vehicle’s air conditioner. The SFTP is based 

on a composite of three different test elements. In addition to the FTP, vehicles generally 

operate over the US06 and SC03 driving schedules as specified in paragraphs (g) and (h) 

of Appendix I of 40 CFR part 86, respectively. In the case of heavy-duty vehicles above 

10,000 pounds GVWR and at or below 14,000 pounds GVWR, SFTP testing involves 

additional driving over the LA-92 driving schedule specified in paragraph (c) of 40 CFR 

part 86, Appendix I, instead of the US06 driving schedule. Note that the US06 driving 

schedule represents about 8.0 miles of relatively aggressive driving; the SC03 driving 

schedule represents about 3.6 miles of urban driving with the air conditioner operating; 

and the LA-92 driving schedule represents about 9.8 miles of relatively aggressive 

driving for commercial trucks. See §§ 1066.815 and 1066.820.

(3) The Highway Fuel Economy Test (HFET) is specified in Appendix I of 40 CFR part 

600. Note that the HFET represents about 10.2 miles of rural and freeway driving with 

an average speed of 48.6 mph and a maximum speed of 60.0 mph. See § 1066.840.

(4) Cold temperature standards apply for CO and NMHC emissions when vehicles 

operate over the FTP at a nominal temperature of -7 °C. See 40 CFR part 86, subpart C, 

and subpart H of this part.

(5) Emission measurement to determine air conditioning credits for greenhouse gas 

standards. In this optional procedure, manufacturers operate vehicles over repeat runs of 
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the AC17 test sequence to allow for calculating credits as part of demonstrating 

compliance with CO2 emission standards. The AC17 test sequence consists of a UDDS 

preconditioning drive, followed by emission measurements over the SC03 and HFET 

driving schedules. See § 1066.845.

(d) The following provisions apply for all testing:

(1) Ambient temperatures encountered by the test vehicle must be (20 to 30) °C, unless 

otherwise specified. Where ambient temperature specifications apply before or between 

test measurements, the vehicle may be exposed to temperatures outside of the specified 

range for up to 10 minutes to account for vehicle transport or other actions to prepare for 

testing. The temperatures monitored during testing must be representative of those 

experienced by the test vehicle. For example, do not measure ambient temperatures near 

a heat source.

(2) Do not operate or store the vehicle at an incline if good engineering judgment 

indicates that it would affect emissions.

(3) If a test is void after collecting emission data from previous test segments, the test 

may be repeated to collect only those data points needed to complete emission 

measurements. You may combine emission measurements from different test runs to 

demonstrate compliance with emission standards. 

(4) Prepare vehicles for testing as described in § 1066.810.

(e) The following figure illustrates the FTP test sequence for measuring exhaust and 

evaporative emissions:
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Figure 1 of § 1066.801–FTP test sequence
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§ 1066.805 Road-load power, test weight, and inertia weight class determination.

(a) Simulate a vehicle’s test weight on the dynamometer using the appropriate equivalent 

test weight shown in Table 1 of this section. Equivalent test weights are established 

according to each vehicle’s test weight basis, as described in paragraph (b) of this section. 

Table 1 also specifies the inertia weight class corresponding to each equivalent test 

weight; the inertia weight class allows for grouping vehicles with a range of equivalent 

test weights. Table 1 follows:
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TABLE 1 OF § 1066.805–EQUIVALENT TEST WEIGHTS (POUNDS)

Test weight Equivalent test Inertia weight 

Up to 1062 1000 1000

1063 to 1187 1125 1000

1188 to 1312 1250 1250

1313 to 1437 1375 1250

1438 to 1562 1500 1500

1563 to 1687 1625 1500

1688 to 1812 1750 1750

1813 to 1937 1875 1750

1938 to 2062 2000 2000

2063 to 2187 2125 2000

2188 to 2312 2250 2250

2313 to 2437 2375 2250

2438 to 2562 2500 2500

2563 to 2687 2625 2500

2688 to 2812 2750 2750

2813 to 2937 2875 2750

2938 to 3062 3000 3000

3063 to 3187 3125 3000

3188 to 3312 3250 3000

3313 to 3437 3375 3500

3438 to 3562 3500 3500

3563 to 3687 3625 3500

3688 to 3812 3750 3500

3813 to 3937 3875 4000

3938 to 4125 4000 4000

4126 to 4375 4250 4000

4376 to 4625 4500 4500

4626 to 4875 4750 4500

4876 to 5125 5000 5000

5126 to 5375 5250 5000

5376 to 5750 5500 5500

5751 to 6250 6000 6000

6251 to 6750 6500 6500

6751 to 7250 7000 7000

7251 to 7750 7500 7500

7751 to 8250 8000 8000

8251 to 8750 8500 8500

8751 to 9250 9000 9000

9251 to 9750 9500 9500

9751 to 10250 10000 10000

10251 to 10750 10500 10500

10751 to 11250 11000 11000

11251 to 11750 11500 11500

11751 to 12250 12000 12000

12251 to 12750 12500 12500

12751 to 13250 13000 13000

13251 to 13750 13500 13500

13751 to 14000 14000 14000
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(b) The test weight basis for non-MDPV heavy-duty vehicles is “adjusted loaded vehicle 

weight”. For all other vehicles, the test weight basis for establishing equivalent test 

weight is “loaded vehicle weight”. These load terms are defined in 40 CFR 86.1803.

(c) For FTP, SFTP, New York City Cycle, HFET, and LA-92 testing, determine roadload forces for each test vehicle at speeds between 9.3 and 71.5 miles per hour. The 

road-load force must represent vehicle operation on a smooth, level road with no wind or 

calm winds, no precipitation, an ambient temperature of approximately 20 °C, and 

atmospheric pressure of 98.21 kPa. You may extrapolate road-load force for speeds 

below 9.3 mph.

§ 1066.810 Vehicle preparation.

(a) Include additional fittings and adapters as required to accommodate a fuel drain at the 

lowest point possible in the tank(s) as installed on the vehicle.

(b) For preconditioning that involves loading an evaporative emission canister with 

butane, provide valving or other means to allow for purging and loading the canister.

(c) For vehicles to be tested for running loss emissions (40 CFR 86.134), prepare the fuel 

tank for measuring temperature and pressure as specified in 40 CFR 86.107–98(e) and (f) 

and 40 CFR 86.134. Vapor temperature measurement is optional during the running loss 

test.

(d) For vehicles to be tested for running loss emissions, prepare the exhaust system by

sealing or plugging all detectable sources of exhaust gas leaks. Inspect or test the exhaust 

system to ensure that there are no leaks that would cause exhaust hydrocarbon emissions 

to be detected as running losses.

(e) The following provisions apply for preconditioning steps to reduce nonfuel emissions 

to normal vehicle background levels for vehicles subject to Tier 3 evaporative emission 

standards under 40 CFR 86.1813:

(1) You must notify us in advance if you plan to perform such preconditioning. This 

notice must include a detailed description of the intended procedures and any

measurements or thresholds for determining when stabilization is complete. You need 

not repeat this notification for additional vehicle testing in the same or later model years 

as long as your preconditioning practice conforms to these procedures.

(2) You may precondition a vehicle as described in paragraph (e)(1) of this section only

within 12 months after the vehicle’s original date of manufacture, except that you may

ask us to approve further preconditioning steps for any testing to address identifiable 

sources of nonfuel emissions beyond what would generally occur with an appropriately 

aged in-use vehicle. For example, you may clean up fluid leaks and you may perform 

further off-vehicle preconditioning for tires or other replacement parts that are less than 

12 months old. You may also replace the spare tire with an aged spare tire, and you may

replace the windshield washer fluid with water.

§ 1066.815 Exhaust emission test procedures for FTP testing.

(a) General. The FTP exhaust emission test sequence consists of a cold-start test and a 

hot-start test as described in § 1066.801.
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(b) PM sampling options. Collect PM using any of the procedures specified in 

paragraphs (b)(1) through (5) of this section and use the corresponding equation in § 

1066.820 to calculate FTP composite emissions. Testing must meet the requirements 

related to filter face velocity as described in 40 CFR 1065.170(c)(1)(vi), except as 

specified in paragraphs (b)(4) and (5) of this section. For procedures involving flow 

weighting, set the filter face velocity to a weighting target of 1.0 to meet the requirements 

of 40 CFR 1065.170(c)(1)(vi). Allow filter face velocity to decrease as a percentage of 

the weighting factor if the weighting factor is less than 1.0. Use the appropriate 

equations in § 1066.610 to show that you meet the dilution factor requirements of § 

1066.110(b)(2)(iii)(B).

(1) You may collect a separate PM sample for transient and stabilized portions of the 

cold-start UDDS and the hot-start UDDS. This may either be done by sampling with 

three bags or four bags. You may omit the stabilized portion of the hot-start test (bag 4) 

and use the stabilized portion of the cold-start test (bag 2) in its place.

(2) You may collect PM on one filter over the cold-start UDDS and on a separate filter 

over the hot-start UDDS.

(3) You may collect PM on one filter over the cold-start UDDS (bag 1 and bag 2) and on 

a separate filter over the 867 seconds of the stabilized portion of the cold-start UDDS and 

the first 505 seconds of the hot-start UDDS (bag 2 and bag 3). Note that this option 

involves duplicate measurements during the stabilized portion of the cold-start UDDS.

(4) You may collect PM on a single filter over the cold-start UDDS and the first 505 

seconds of the hot-start UDDS. If you use this method, adjust your sampling system flow 

rate to weight the filter face velocity over the three intervals of the FTP based on 

weighting targets of 0.43 for bag 1, 1.0 for bag 2, and 0.57 for bag 3.

(5) You may collect PM on a single filter over the cold-start UDDS and the full hot-start 

UDDS. If you use this method, adjust your sampling system flow rate to weight the filter 

face velocity based on weighting targets of 0.75 for the cold-start UDDS and 1.0 for the 

hot-start UDDS.

(c) Gaseous sampling options. Collect gaseous samples using any of the following 

procedures:

(1) You may collect a single sample for a full UDDS (cold-start or hot-start).

(2) You may sample emissions separately for transient and stabilized portions of any 

UDDS.

(3) You may omit the stabilized portion of the hot-start test (bag 4) and use the stabilized 

portion of the cold-start test (bag 2) in its place.

(d) Test sequence. Follow the exhaust emission measurement procedures specified in §§ 

1066.410 through 1066.425, subject to the following exceptions and additional 

provisions:

(1) Take the following steps for the cold-start test:

(i) Precondition the vehicle as described in § 1066.816. Initiate the cold-start test 

following the 12 to 36 hour soak period.

(ii) Start sampling and recording simultaneously with starting the vehicle. Place the 

vehicle in gear 15 seconds after engine starting, which is 5 seconds before the first 

acceleration.
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(iii) At the end of the deceleration scheduled to occur 505 seconds into the cold-start 

UDDS, simultaneously switch all the sample flows from the cold-start transient interval 

to the stabilized interval, stopping all cold-start transient interval sampling and recording, 

including background sampling. Reset integrating devices for the stabilized interval and 

indicate the end of the cold-start interval in the recorded data. Operate the vehicle over 

the remainder of the UDDS. Turn the engine off 2 seconds after the end of the last 

deceleration in the stabilized interval (1,369 seconds after the start of the driving 

schedule).

(iv) Five seconds after the engine stops running, stop all stabilized interval sampling and 

recording, including background sampling. Stop any integrating devices for the 

stabilized interval and indicate the end of the stabilized interval in the recorded data. 

Note that the 5 second delay is intended to account for sampling system transport.

(2) Take the following steps for the hot-start test:

(i) Initiate the hot-start test (9 to 11) minutes after the end of the sample period for the 

cold-start UDDS. 

(ii) Repeat the steps in paragraph (d)(1)(ii) of this section. Operate the vehicle over the 

first 505 seconds of the UDDS. At the end of the deceleration scheduled to occur 505 

seconds into the hot-start UDDS, turn off the engine and simultaneously stop all hot-start 

sampling and recording, including background sampling, and any integrating devices.

(iii) For tests that do not include bag 4 operation, turn the engine off. To include bag 4 

measurement, operate the vehicles over the remainder of the UDDS and conclude the 

testing as described in paragraphs (d)(1)(iii) and (iv) of this section.

(3) This completes the procedure for measuring FTP exhaust emissions. See § 1066.801 

and subpart J of this part for continuing the test sequence to measure evaporative or 

refueling emissions. 

§ 1066.816 Vehicle preconditioning for FTP testing.

Precondition the test vehicle before the FTP exhaust measurement as described in 40 

CFR 86.132. 

§ 1066.820 Composite calculations for FTP exhaust emissions.

(a) Determine the mass of exhaust emissions of each pollutant for each FTP test interval 

as described in § 1066.605.

(b) Calculate the final composite gaseous test results as a mass-weighted value, e[emission]-

FTPcomp, in grams per mile using the following equation:

c h

[emission]-FTPcomp

ct cs ht hs

0.43 0.57 m me

D D D D

   

             

Eq. 1066.820-1

Where:

mc = the combined mass emissions determined from the cold-start UDDS test interval 

(generally known as bag 1 and bag 2), in grams.

Dct = the measured driving distance from the transient portion of the cold-start test (bag 

1), in miles.
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Dcs = the measured driving distance from the stabilized portion of the cold-start test (bag 

2), in miles.

mh = the combined mass emissions determined from the hot-start UDDS test interval in 

grams. This is the hot-stabilized portion from either the first or second UDDS (bag 2, 

unless you measure bag 4), in addition to the hot transient portion (bag 3).

Dht = the measured driving distance from the transient portion of the hot-start test (bag 3), 

in miles.

Dhs = the measured driving distance from the stabilized portion of the hot-start test (bag 

4), in miles. Set Dhs = Dcs for testing where the hot-stabilized portion of the UDDS is not 

run.

(c) Calculate the final composite PM test results as a mass-weighted value, ePM-FTPcomp, in 

grams per mile as follows:

(1) Use the following equation for PM measured as described in § 1066.815(b)(1), (2), or 

(3):

PM-cUDDS PM-hUDDS

PM-FTPcomp

ct cs ht hs

0.43 0.57 m me

D D D D

   

             

Eq. 1066.820-2

Where:

mPM-cUDDS = the combined PM mass emissions determined from the cold-start UDDS test 

interval (bag 1 and bag 2), in grams, as calculated using Eq. 1066.605-2.

mPM-hUDDS = the combined PM mass emissions determined from the hot-start UDDS test 

interval (bag 3 and bag 4), in grams, as calculated using Eq. 1066.605-2. This is the hotstabilized portion from either the first or second UDDS (bag 2, unless you measure bag 

4), in addition to the hot transient portion (bag 3).

(2) Use the following equation for PM measured as described in § 1066.815(b)(4):

   

PM

PM-FTPcomp

ct cs ht 0.43 0.57

m

e

D D D



   

Eq. 1066.820-3

Where:

mPM = the combined PM mass emissions determined from the cold-start UDDS test 

interval and the first 505 seconds of the hot-start UDDS test interval (bag 1, bag 2, and 

bag 3), in grams, as calculated using Eq. 1066.605-3.

(3) Use the following equation for PM measured as described in § 1066.815(b)(5):

   

PM

PM-FTPcomp

ct cs ht hs 0.43 0.57

m

e

D D D D



    

Eq. 1066.820-4

Where:

mPM = the combined PM mass emissions determined from the cold-start UDDS test 

interval and the hot-start UDDS test interval (bag 1, bag 2, bag 3, and bag 4), in grams, as 

calculated using Eq. 1066.605-4.
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§ 1066.830 Supplemental Federal Test Procedures; overview.

Sections 1066.831 and 1066.835 describe the detailed procedures for the Supplemental 

Federal Test Procedure (SFTP). This testing applies for all vehicles subject to the SFTP 

standards in 40 CFR part 86, subpart S. The SFTP test procedure consists of FTP testing 

and two additional test elements—a sequence of vehicle operation with more aggressive 

driving and a sequence of vehicle operation that accounts for the impact of the vehicle’s 

air conditioner. 

(a) The SFTP standard applies as a composite representing the three test elements. The 

emission results from the aggressive driving test element (§ 1066.831), the air 

conditioning test element (§ 1066.835), and the FTP test element (§ 1066.820) are 

analyzed according to the calculation methodology and compared to the applicable SFTP 

emission standards as described in 40 CFR part 86, subpart S.

(b) The test elements of the SFTP may be run in any sequence that includes the specified 

preconditioning steps.

§ 1066.831 Exhaust emission test procedures for aggressive driving.

(a) This section describes how to test using the US06 or LA-92 driving schedule. The 

US06 driving schedule can be divided into two test intervals—the US06 City cycle 

comprises the combined portions of the cycle from 1 to 130 seconds and from 495 to 596 

seconds, and the US06 Highway cycle comprises the portion of the cycle between 130 

and 495 seconds. See § 1066.801 for further information on the driving schedules.

(b) Take the following steps to precondition vehicles for testing under this section:

(1) Drain and refill the vehicle’s fuel tank(s) in any of the following cases:

(i) For aggressive-driving tests that do not follow FTP or HFET testing.

(ii) For a test element that starts more than 72 hours after the most recent FTP or HFET 

measurement (with or without evaporative emission measurements).

(iii) For testing in which the test vehicle has not remained in an area where ambient 

temperatures were within the range specified for testing since the previous FTP or HFET.

(2) Keep ambient temperatures within the ranges specified for test measurements 

throughout the preconditioning sequence.

(3) Warm up the vehicle to a stabilized condition as follows:

(i) Push or drive the vehicle onto the dynamometer.

(ii) Operate the vehicle one time over one of the driving schedules specified in this 

paragraph (b)(3)(ii). You may ask us to use a particular preconditioning driving schedule 

if that is related to fuel effects on adaptive memory systems. For our testing, we will 

generally operate the vehicle over the same preconditioning cycle that will be used for 

testing in this section. You may exercise your sampling equipment, but you may not 

determine emissions results during preconditioning. Choose from the following driving 

schedules:

(A) The first 505 seconds of the UDDS (bag 1)

(B) The last 867 seconds of the UDDS (bag 2).

(C) The HFET driving schedule.
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(D) US06 driving schedule or, for heavy-duty vehicles above 10,000 pounds GVWR with 

a power-to-weight ratio at or below 0.024 hp/lbm, just the highway portion of the US06 

driving schedule. 

(E) The SC03 driving schedule.

(F) The LA-92 driving schedule. 

(4) Allow the vehicle to idle for (1 to 2) minutes. This leads directly into the test 

measurements described in paragraph (c) of this section.

(c) For testing involving the full US06 driving schedule, you may collect emissions from 

separate city and highway test intervals (see 40 CFR part 600), or you may collect 

emissions over the full US06 driving schedule as a single test interval. Take the 

following steps to measure emissions over separate city and highway test intervals:

(1) At 130 seconds, simultaneously stop all US06 City, and start all US06 Highway

sampling, recording, and integrating (including background sampling). At 136 seconds 

(before the acceleration), record the measured dynamometer roll revolutions.

(2) At 495 seconds, simultaneously stop all US06 Highway, and start all US06 City

sampling, recording, and integrating (including background sampling). At 500 seconds 

(before the acceleration), record the measured dynamometer roll revolutions.

(3) Except as specified in paragraph (c)(4) of this section, treat the emissions from the 

first and second portions of the US06 City test interval as a single sample.

(4) If you collect gaseous emissions over separate city and highway test intervals, you 

may still collect PM over the full US06 driving schedule as a single test interval. If you 

do this, calculate a composite dilution factor based on city and highway emissions using 

Eq. 1066.610-4 to show that you meet the dilution factor requirements of § 

1066.110(b)(2)(iii)(B). 

(d) For diesel-fueled vehicles, measure THC emissions on a continuous basis as 

described in 40 CFR part 1065. For separate measurement of the city and highway test 

intervals as described in paragraph (c) of this section, perform separate calculations for 

each portion of the test cycle.

(e) Follow the exhaust emission measurement procedures specified in §§ 1066.410 

through 1066.425, subject to the following exceptions and additional provisions:

(1) Following the preconditioning specified in paragraph (b) of this section, place the 

vehicle in gear and simultaneously start sampling and recording. Begin the first 

acceleration 5 seconds after placing the vehicle in gear.

(2) Operate the vehicle over the full US06 driving schedule, except as follows:

(i) For heavy-duty vehicles above 10,000 pounds GVWR, operate the vehicle over the 

LA-92 driving schedule.

(ii) Heavy-duty vehicles at or below 10,000 pounds GVWR with a power-to-weight ratio 

at or below 0.024 hp/lbm may be certified using only the highway portion of the US06 

driving schedule as described in 40 CFR 86.1816.

(iii) All heavy-duty vehicles shall be tested at their adjusted loaded vehicle weight as 

described in 40 CFR 86.1816.

(3) Turn the engine off 2 seconds after the end of the last deceleration. Five seconds after 

the engine stops running, stop all sampling and recording, including background 

sampling. Stop any integrating devices and indicate the end of the test cycle in the 
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recorded data. Note that the 5 second delay is intended to account for sampling system 

transport.

(4) Correct calculated NOx emissions as described in § 1066.615(a)(1).

§ 1066.835 Exhaust emission test procedure for SC03 emissions.

This section describes how to test using the SC03 driving schedule (see § 1066.801). 

This procedure is designed to determine gaseous exhaust emissions while simulating an 

urban trip on a hot summer day. The provisions of 40 CFR part 86 and 40 CFR part 600 

waive SC03 testing for some vehicles; in those cases, calculate SFTP composite 

emissions by adjusting the weighting calculation as specified in 40 CFR part 86, subpart 

S.

(a) Drain and refill the vehicle’s fuel tank(s) if testing starts more than 72 hours after the 

last drain and fill operation.

(b) Keep the vehicle in an environment meeting the conditions described in paragraph (f) 

of this section throughout the preconditioning sequence. 

(c) Warm up the vehicle to a stabilized condition as follows: 

(1) Push or drive the test vehicle onto the dynamometer.

(2) Close the vehicle’s windows before testing.

(3) The test cell and equipment must meet the specifications in paragraph (e) of this 

section. Measure and control ambient conditions as specified in paragraph (f) of this 

section.

(4) Set the vehicle’s air conditioning controls by selecting A/C mode and “maximum”, 

setting airflow to “recirculate” (if so equipped), selecting the highest fan setting, and 

turning the A/C temperature to full cold (or 72 °F for automatic systems). Turn the 

control to the “on” position before testing so the air conditioning system is active 

whenever the engine is running.

(5) Perform a preconditioning drive by operating the test vehicle one time over the first 

505 seconds of the UDDS (bag 1), the last 867 seconds of the UDDS (bag 2), or the SC03 

driving schedule. If the air conditioning test sequence starts more than 2 hours after a 

different exhaust emission test, you may instead operate the vehicle one time over the full 

UDDS.

(6) Following the preconditioning drive, turn off the test vehicle and the vehicle cooling 

fan(s) and allow the vehicle to soak for (9 to 11) minutes.

(d) Follow the exhaust emission measurement procedures specified in §§ 1066.410 

through 1066.425, subject to the following exceptions and additional provisions:

(1) Place the vehicle in gear 15 seconds after engine starting, which is 3 seconds before 

the first acceleration. Follow the SC03 driving schedule. 

(2) Turn the engine off 2 seconds after the end of the last deceleration. Five seconds after 

the engine stops running, stop all sampling and recording, including background 

sampling. Stop any integrating devices any indicate the end of the test cycle in the 

recorded data. Note that the 5 second delay is intended to account for sampling system 

transport.

(3) Correct calculated NOx emissions as described in § 1066.615(a)(2).

(e) The following requirements apply for the test cell and cooling fan configuration:
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(1) Minimum test cell size. The test cell must be at least 20 feet wide, 40 feet long, and 

10 feet high, unless we approve the use of a smaller test cell. We will approve this only

if you demonstrate that the smaller test cell is capable of meeting all the requirements of 

this section.

(2) Vehicle frontal air flow. Verify that the fan configuration meets the requirements of § 

1066.105(c)(3).

(f) Maintain ambient conditions as follows: 

(1) Ambient temperature and humidity. Measure and record ambient temperature and 

humidity in the test cell at least once every 30 seconds during the sampling period.

Alternatively, if you collect data of at least once every 12 seconds, you may use a moving 

average of up to 30 second intervals to measure and record ambient temperature and 

humidity. Control ambient temperature throughout the test sequence to 35.0 ±3.0 °C. 

Control ambient temperature during emission sampling to (33.6 to 36.4) °C on average. 

Control ambient humidity during emission sampling as described in § 1066.420(d).

(2) Conditions before and after testing. Use good engineering judgment to demonstrate 

that you meet the specified instantaneous temperature and humidity tolerances in 

paragraphs (f)(1) of this section at all times before and between emission measurements.

(3) Solar heat load. Simulate solar heating as follows:

(i) You may use a metal halide lamp, a sodium lamp, or a quartz halogen lamp with 

dichroic mirrors as a radiant energy emitter. We may also approve the use of a different 

type of radiant energy emitter if you demonstrate that it meets the requirements of this 

section.

(ii) We recommend achieving radiant heating with spectral distribution characteristics as 

described in the following table:

TABLE 1 OF § 1066.835–RECOMMENDED SPECTRAL DISTRIBUTION

Band width (nm) Percent of total spectrum

Lower limit (%) Upper limit (%)

<320a — 0

320–400 0 7

400–780 45 55

>780 35 53

aNote that you may need to filter the UV region between 280 and 320 nm.

(iii) Determine radiant energy intensity experienced by the vehicle as the average value 

between two measurements along the vehicle’s centerline, one at the base of the 

windshield and the other at the bottom of the rear window (or equivalent location for 

vehicles without a rear window). This value must be 850 ±45 W/m

2

. Instruments for 

measuring radiant energy intensity must meet the following minimum specifications:

(A) Sensitivity of 9 microvolts per W/m2.

(B) Response time of 5 seconds. For purposes of this requirement, “response time” 

means the time for the instrument to reach 95 percent of its equilibrium response after a 

step change in radiant intensity.
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(C) Cosine response error of no more than ± 1 % for 0–70 degree zenith angles. The 

cosine response error is the percentage difference between the intensity measured at a 

given angle and a reference value, where the reference value is the intensity predicted 

from the zero-degree intensity and the cosine of the incident angle.

(D) When comparing measured values for radiant energy to reference values, each 

measured value over the full range of measurement may not deviate from the 

corresponding reference value by more than ±0.5 % of the analyzer range’s maximum 

value.

(iv) Check the uniformity of radiant energy intensity at least every 500 hours of emitter 

usage or every 6 months, whichever is sooner, and after any major modifications 

affecting the solar simulation. Determine uniformity by measuring radiant energy

intensity as described in paragraph (f)(4)(iii) of this section at each point of a 0.5 m grid 

over the vehicle’s full footprint, including the edges of the footprint, at an elevation 1 m 

above the floor. Measured values of radiant energy intensity must be between (722 and 

978) W/m2at all points.

§ 1066.840 Highway fuel economy test procedure.

This section describes the procedure for the highway fuel economy test (HFET). This 

test involves emission sampling and fuel economy measurement for certain vehicles as 

described in 40 CFR part 86, subpart S, and in 40 CFR part 600. See § 1066.801 for 

further information on the driving schedules. Follow the exhaust emission measurement 

procedures specified in §§ 1066.410 through 1066.425, subject to the following 

exceptions and additional provisions:

(a) Perform the HFET immediately following the FTP when this is practical. If the 

HFET procedure starts more than 3 hours after an FTP (including evaporative emission 

measurements, if applicable), operate it over one UDDS to precondition the vehicle. We 

may approve additional preconditioning in unusual circumstances.

(b) Operate the vehicle over the HFET driving schedule for preconditioning. Allow the 

vehicle to idle for 15 seconds (with the vehicle in gear), then start a repeat run of the 

HFET driving schedule and simultaneously start sampling and recording. 

(c) Turn the engine off at the end of the HFET driving schedule and stop all sampling and 

recording, including background. Stop any integrating devices and indicate the end of 

the test cycle in the recorded data.

§ 1066.845 AC17 air conditioning efficiency test procedure.

(a) Overview. This section describes a voluntary procedure for measuring the net impact 

of air conditioner operation on CO2 emissions. See 40 CFR 86.1868 for provisions 

describing how to use these procedures to calculate credits and otherwise comply with 

emission standards. 

(b) Test cell. Operate the vehicle in a test cell meeting the specifications described in § 

1066.832(e). You may add airflow up to at a maximum of 4 miles per hour during 

engine idling and when the engine is off if that is needed to meet ambient temperature or 

humidity requirements.
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(c) Ambient conditions. Measure and control ambient conditions as specified in § 

1066.832(f), except that you must control ambient temperature during emission sampling 

to (22.0 to 28.0) °C throughout the test and (23.5 to 26.5) °C on average. These 

tolerances apply to the combined SC03 and HFET drive cycles during emission 

sampling. Note that you must set the same ambient temperature target for both the air 

conditioning on and off portions of emission sampling. Control ambient temperature 

during the preconditioning cycle and 30 minute soak to 25.0 ±5.0 °C. For these same 

modes with no emission sampling, target the specified ambient humidity levels, but you 

do not need to meet the humidity tolerances. Note that solar heating is disabled for 

certain test intervals as described in this section.

(d) Interior air temperature measurement. Measure and record the vehicle’s interior air 

temperature at least once every 5 seconds during the sampling period. Measure 

temperature at the outlet of the center-most duct on the dashboard, and approximately 30 

mm behind the driver’s headrest and passenger’s headrest. 

(e) Air conditioning system settings. For testing that requires the air conditioning to be 

operating, set the vehicle’s air conditioning controls as follows: 

(1) For automatic systems, set the temperature control to 72 °F (22 °C).

(2) For manual systems, select A/C mode, set the temperature to full cold and 

“maximum”, set airflow to “recirculate” (if so equipped), and select the highest fan 

setting. During the first idle period of the SC03 driving schedule (between 186 and 204 

seconds), reduce the fan speed setting to nominally 50 % of maximum fan speed, set 

airflow to “fresh air” (if so equipped), and adjust the temperature setting to target a 

temperature of 55° F (13 °C) at the dashboard air outlet. Maintain these settings for the 

remainder of the test. You may rely on prior temperature measurements to determine the 

temperature setting; however, if the system is unable to meet the 55 °F (13 °C) target, 

you may instead set airflow to “fresh air” and temperature to full cold. If the vehicle is 

equipped with technology that defaults to recirculated air at ambient temperatures above 

75 °F (22 °C), that technology should remain enabled throughout the test; this may mean 

not setting the airflow to “recirculate” at the start and not setting the airflow to "fresh air" 

during the first idle period of the SCO3 driving schedule.

(f) Test procedure. Follow the exhaust emission measurement procedures specified in §§ 

1066.410 through 1066.425, subject to the following exceptions and additional 

provisions:

(1) Prepare each test vehicle for a series of tests according to 40 CFR 86.132-00(a) 

through (g). If the vehicle has been tested within the last 36 hours concluding with a 12 

to 36 hour soak, continue to paragraph (f)(2) of this section; otherwise perform an 

additional UDDS preconditioning cycle that concludes with a 12 to 36 hour soak. You 

may use a forced cooldown system to bring critical vehicle temperatures to within soak 

temperature limits. Critical temperatures include transmission oil, engine oil, engine 

coolant, and cabin air temperatures.

(2) Open the vehicle’s windows and operate the vehicle over a preconditioning UDDS 

with no solar heating and with the air conditioning off. At the end of the preconditioning 

drive, turn off the test vehicle and all cooling fans. 
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(3) Turn on solar heating within one minute after turning off the engine. Once the solar 

energy intensity reaches 805 W/m2, let the vehicle soak for 30 ±1 minutes. You may

alternatively rely on prior measurements to start the soak period after a defined period of 

warming up to the specified solar heat load. Close the vehicle’s windows at the start of 

the soak period; ensure that the windows are adequately closed where instrumentation 

and wiring pass through to the interior.

(4) Turn the air conditioning control to the “on” position before testing so the air 

conditioning system is active whenever the engine is running. Place the vehicle in gear 

15 seconds after engine starting, which is 3 seconds before the first acceleration. At the 

end of the driving schedule, simultaneously switch all the sampling, recording, and 

integrating from SC03 to HFET, including background sampling. Indicate the end of the 

test cycle in the recorded data. Record the measured dynamometer roll revolutions 

corresponding to the SC03 driving schedule.

(5) Directly following the SC03 driving schedule, operate the vehicle over the HFET 

driving schedule. Turn the vehicle off at the end of the driving schedule and 

simultaneously stop all sampling, recording, and integrating, including background 

sampling. Indicate the end of the test cycle in the recorded data. Record the measured 

dynamometer roll revolutions corresponding to the HFET drive schedule. Turn off the 

solar heating.

(6) Allow the vehicle to remain on the dynamometer for (10 to 15) minutes after emission 

sampling has concluded. Repeat the testing described in paragraphs (f)(1) through (5) of 

this section and turn off the vehicle’s air conditioner and the solar heating throughout the 

test run. The windows may be open or closed.

(g) Calculations. (1) Determine the mass of CO2 emissions for each of the two test 

intervals as described in § 1066.605.

(2) Calculate the composite mass-weighted emissions of CO2, eCO2-AC17comp, representing 

the average of the SC03 and HFET emissions, in grams per mile using the following 

equation:

SC03 HFET

CO2-AC17comp

SC03 HFET

0.5 0.5 m me

D D

   

           

Eq. 1066.845-1

Where:

mSC03 = mass emissions from the SC03 test interval, in grams.

DSC03 = measured driving distance during the SC03 test interval, in miles.

mHFET = mass emissions from the HFET test interval, in grams.

DHFET = measured driving distance during the HFET test interval, in miles.

Subpart J—EVAPORATIVE EMISSION TEST PROCEDURES

§ 1066.901 Applicability and general provisions.

This subpart describes how to measure evaporative and refueling emissions from test 

vehicles. The provisions of §§ 1066.910 through 1066.930 include general provisions for 
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equipment and calculations related to evaporative and refueling emissions. The 

provisions of §§ 1066.950 through 1066.985 describe provisions that apply specifically to 

motor vehicles subject to standards under 40 CFR part 86, subpart S, or 40 CFR part 

1037. 

TEST EQUIPMENT AND CALCULATIONS FOR EVAPORATIVE AND REFUELING EMISSIONS

§ 1066.910 SHED enclosure specifications.

Enclosures for evaporative and refueling emissions must meet the specifications 

described in 40 CFR 86.106-96, 86.107-96(a), and 86.107-98(a).

§ 1066.915 Enclosures; auxiliary systems and equipment.

Enclosures for evaporative and refueling emissions must be equipped with fans, blowers, 

and measurement and data recording equipment as described in 40 CFR 86.107-98(b) 

through (h) and (j).

§ 1066.920 Enclosure calibrations.

Enclosures for evaporative and refueling emissions must meet the calibration 

specifications described in 40 CFR 86.116-94 and 86.117-96.

§ 1066.925 Enclosure calculations for evaporative and refueling emissions.

Calculate emissions for evaporative emissions as described in 40 CFR 86.143-96. 

Calculate emissions for refueling emissions as described in 40 CFR 86.143-96 and 

86.156-98.

§ 1066.930 Equipment for point-source measurement of running losses.

For point-source measurement of running loss emissions, use equipment meeting the 

specifications in 40 CFR 86.107-96(i)

EVAPORATIVE AND REFUELING EMISSION TEST PROCEDURES FOR MOTOR VEHICLES

§ 1066.950 Fuel temperature profile.

Develop fuel temperature profiles for running loss testing as described in 40 CFR 86.129-

94(d).

§ 1066.955 Diurnal emission test.

Test vehicles for diurnal emissions as described in 40 CFR 86.133-96.

§ 1066.960 Running loss test.

Test vehicles for running loss emissions as described in 40 CFR 86.134-96.

§ 1066.965 Hot soak test.

Test vehicles for hot soak emissions as described in 40 CFR 86.138-96.
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§ 1066.970 Refueling test for liquid fuels.

Except as described in § 1066.975, test vehicles for refueling emissions as described in 

40 CFR 86.150-98, 86.151-98, 86.152-98, and 86.154-98. Keep records as described in 

40 CFR 86.155-98.

§ 1066.971 Vehicle and canister preconditioning for the refueling test.

Precondition vehicles for the refueling emission test as described in 40 CFR 86.153-98.

§ 1066.975 Refueling test for LPG.

For vehicles designed to operate on liquefied petroleum gas, measure refueling emissions 

as described in 40 CFR 86.157-98.

§ 1066.980 Fuel dispensing spitback procedure.

Test vehicles for spitback emissions as described in 40 CFR 86.146-96.

§ 1066.985 Fuel storage system leak test procedure.

(a) Scope. Perform this test as required in the standard-setting part to verify that there are 

no significant leaks in your fuel storage system.

(b) Measurement principles. Leaks are detected by measuring pressure, temperature, and 

flow to calculate an equivalent orifice diameter for the system. Use good engineering 

judgment to develop and implement leak test equipment. You may not tighten fittings or 

connections in the vehicle’s fuel system to prepare the vehicle for testing. 

(c) Measurement equipment. Your leak test equipment must meet the following 

requirements:

(1) Pressure, temperature, and flow sensors must be calibrated with NIST-traceable 

standards. 

(2) Correct flow measurements to standard reference conditions.

(3) Leak test equipment must have the ability to pressurize fuel storage systems to at least 

4.1 kPa and have an internal leak rate of less than 0.20 standard liters per minute.

(4) You must be able to attach the test equipment to the vehicle without permanent 

alteration of the fuel storage or evaporative emission control systems. For any testing that 

involves pressurizing the fuel system and detecting leaks at access points away from the 

fuel fill pipe, the gas cap must be installed in the production configuration. For the test 

point at or near the fuel fill pipe, attaching the test equipment may involve adding an 

extension to the fuel fill pipe that incorporates the access point to the fuel system. If the 

extension apparatus has a fixed cap, the vehicle’s gas cap must be tested separately as 

described in paragraph (d)(9) of this section. This separate testing is not required if the 

extension apparatus incorporates the vehicle’s gas cap.

(5) The point of attachment to the fuel storage system must allow pressurization to test 

system integrity of the fuel tank and of fuel lines and vapor lines reaching up to and 

including the gas cap and the evaporative canister. The evaporative system test port 

available on some vehicles is an example of an effective attachment point.

(d) Leak test procedure. Test a vehicle’s fuel storage system for leaks as follows:

(1) Refuel vehicle to 40 % of its nominal fuel tank capacity.
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(2) Soak the vehicle for 6 to 24 hours at a temperature between (20 and 30) °C; record 

this setpoint temperature and maintain temperatures throughout the leak test at this 

setpoint temperature within a tolerance ±2 °C.

(3) Before performing the test, purge the fuel storage system of any residual pressure, 

bringing the system into equilibrium with ambient pressure.

(4) Seal the evaporative canister’s vent to atmosphere and ensure that the vehicle’s purge 

valve is closed.

(5) Attach the leak test equipment to the vehicle.

(6) Pressurize the fuel storage system with N2 or another inert gas to at least 2.4 kPa. Use 

good engineering judgment to avoid overpressurizing the system.

(7) Maintain gas flow through the system for at least 180 seconds, ensuring that the flow 

reading is stable for an effective leak diameter of ±0.002 inches.

(8) Use the following equation, or a different equation you develop based on good 

engineering judgment, to calculate the effective leak diameter, deff:

   

2

0.5057

gas

eff

in atmos in atmos

N

7.844

V

d

p p p p

SG T

   

 

  



 

Where:

deff = effective leak diameter, in inches, expressed to at least two decimal places.

Vgas = volumetric flow of gas, in m3/s.

pin = inlet pressure to orifice, in kPa.

patmos = atmospheric pressure, in kPa.

SGN2 = specific gravity of N2 relative to air at 101.325 kPa and 15.5 °C = 0.967.

T = temperature of flowing medium, in K.

(9) Repeat the test described in this paragraph (c) for each access point described in the 

application for certification. Use each test result (without averaging) to determine 

whether the vehicle passes the leak standard.

(10) Gas caps may need to be tested separately for leaks as described in paragraph (c)(4) 

of this section. Test the gas caps using commercially available flow equipment such as 

that used for inspection-and-maintenance programs for motor vehicles to determine a 

leak rate in cubic centimeters per minute resulting from a sustained tank pressure of 7.5 

kPa. Correct the leak rate to standard reference conditions, based on the measured leak 

rate corresponding to atmospheric pressure. The corrected leak value may not exceed 60 

cubic centimeters per minute.

(11) You may use special or alternative test procedures as described in 40 CFR 

1065.10(c).

(e) Equipment calibration. Use good engineering judgment to calibrate the leak check 

device.

Subpart K—DEFINITIONS AND OTHER REFERENCE MATERIAL
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§ 1066.1001 Definitions.

The definitions in this section apply to this part. The definitions apply to all subparts 

unless we note otherwise. Other terms have the meaning given in 40 CFR part 1065. 

The definitions follow:

Average means the arithmetic mean of a sample.

Bag 1 means relating to the first 505 seconds of the FTP cold-start test interval. 

Note that the term bag 1 may also apply to measurement of constituents that are not 

collected in a bag, such as PM and continuously measured THC.

Bag 2 means relating to the last 867 seconds of the FTP cold-start test interval.

Bag 3 means relating to the first 505 seconds of the FTP hot-start test interval. 

Bag 4 means relating to the last 867 seconds of the FTP hot-start test interval, if 

run. Note that bag 2 is generally used in place of bag 4.

Base inertia means a value expressed in mass units to represent the rotational 

inertia of the rotating dynamometer components between the vehicle driving tires and the 

dynamometer torque-measuring device, as specified in § 1066.250.

C1-equivalent means a convention of expressing HC concentrations based on the 

total number of carbon atoms present, such that the C1-equivalent of an HC concentration 

equals the concentration multiplied by the mean number of carbon atoms in each HC 

molecule. For example, the C1-equivalent of 10 ppm of propane (C3H8) is 30 ppm. C1-

equivalent concentration values may be denoted as “ppmC” in the standard-setting part. 

Densities may also be expressed on a C1 basis. Note that calculating HC masses from 

concentrations and densities is only valid where they are each expressed on the same 

carbon basis.

Driving schedule means a series of vehicle speeds that a vehicle must follow during a 

test. Driving schedules are specified in the standard-setting part. A driving schedule may

consist of multiple test intervals.

Duty cycle means a set of weighting factors and the corresponding test cycles, where the 

weighting factors are used to combine the results of multiple test intervals into a 

composite result.

FTP means one of the following:

(1) The test cycle consisting of one UDDS as specified in paragraph (a) of Appendix I of 

40 CFR part 86, followed by a 10-minute soak with the engine off and repeat driving 

through the first 505 seconds of the UDDS. See § 1066.801(c)(1).

(2) The entire test procedure for measuring exhaust and/or evaporative emissions as 

described in § 1066.801(c).

Footprint has the meaning given in the standard-setting part.

HFET means the test cycle specified in Appendix I of 40 CFR part 600.

LA-92 means the test cycle specified in Appendix I, paragraph (c), of 40 CFR part 

86.

Nonmethane organic gas (NMOG) means the combination of organic gases other than 

methane as calculated in § 1066.635. Note that for this part, the organic gases are 

summed on a mass basis without any adjustment for photochemical reactivity.
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Parts-per-million (ppm) means ppm on a molar basis. For hydrocarbon concentrations 

including HC, THC, NMHC, and NMOG, ppm means ppm on a C1-equivalent molar 

basis.

Road-load coefficients means sets of A, B, and C road-load force coefficients that are 

used in the dynamometer road-load simulation, where road-load force at speed v equals A 

+ B∙v + C∙v

2

.

SC03 means the test cycle specified in Appendix I, paragraph (h), of 40 CFR part 

86.

SFTP means the collection of test cycles as given in 1066.801(c)(2).

Standard reference conditions means the following:

(1) Standard pressure is 101.325 kPa.

(2) Standard temperature is 293.15 K.

Test interval means a period over which a vehicle’s emission rates are determined 

separately. For many standards, compliance with the standard is based on a weighted 

average of the mass emissions from multiple test intervals. For example, the standardsetting part may specify a complete duty cycle as a cold-start test interval and a hot-start 

test interval. In cases where multiple test intervals occur over a duty cycle, the standardsetting part may specify additional calculations that weight and combine results to arrive 

at composite values for comparison against the applicable standards.

Test weight has the meaning given in §§ 1066.410(b) or 1066.805.

UDDS means the test cycle specified in Appendix I, paragraph (a), of 40 CFR 

part 86.

US06 means the test cycle specified in Appendix I, paragraph (g), of 40 CFR part 

86.

Unloaded coastdown means a dynamometer coastdown run with the vehicle 

wheels removed from the roll surface.

We (us, our) means the Administrator of the Environmental Protection Agency

and any authorized representatives.

§ 1066.1005 Symbols, abbreviations, acronyms, and units of measure.

The procedures in this part generally follow either the International System of Units (SI) 

or the United States customary units, as detailed in NIST Special Publication 811, which 

we incorporate by reference in § 1066.1010. See 40 CFR 1065.20 for specific provisions 

related to these conventions. This section summarizes the way we use symbols, units of 

measure, and other abbreviations.

(a) Symbols for quantities. This part uses the following symbols and units of measure for 

various quantities:

Symbol Quantity Unit Unit symbol Unit in terms of SI 

base units

 atomic hydrogen to carbon ratio mole per mole mol/mol 1

A area square meter m

2 m2

A vehicle frictional load pound force or newton lbf or N kg∙s-2

Am calculated vehicle frictional load pound force or newton lbf or N kg∙s-2

a0

intercept of least squares 

regression

a1 slope of least squares regression

a acceleration feet per second squared or ft/s2or m/s2 m∙s-2
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meters per second squared

B

vehicle load from drag and 

rolling resistance

pound force per mile per hour 

or newton second per meter lbf/mph or N∙s/m kg∙s-1

∙m-1

 ratio of diameters meter per meter m/m 1

 atomic oxygen to carbon ratio mole per mole mol/mol 1

c conversion factor

C

vehicle-specific aerodynamic 

effects

pound force per mile per hour 

squared or newton second 

squared per meter squared

lbf/mph2or N∙s2/m2kg∙m-2

C#

number of carbon atoms in a 

molecule C#

number of carbon 

atoms in a molecule C#

Cd discharge coefficient

CDA drag area meter squared m

2 m2

Cfflow coefficient

Cp heat capacity at constant pressure joule per kelvin J/K J∙K-1

Cv heat capacity at constant volume joule per kelvin J/K J∙K-1

d diameter meters m m

D distance miles or meters mi or m m

D slope correlation

pound force per mile per hour 

squared or newton second 

squared per meter squared

lbf/mph2or N∙s2/m2kg∙m-2

DF dilution factor 1

e mass weighted emission result grams/mile g/mi

F force pound force or newton lbf or N kg∙s-2

f frequency hertz Hz s

-1

fn angular speed (shaft) revolutions per minute r/min 2∙π∙60-1∙m·m-1·s-1

FC friction compensation error horsepower or watt W kg·m2·s-3

FR Road-load force pound force or newton lbf or N kg∙s-2

g gravitational acceleration meters per second squared m/s2 m∙s-2

 ratio of specific heats

(joule per kilogram kelvin) 

per (joule per kilogram 

kelvin) 

(J/(kg∙K))/(J/(kg∙K)) 1

 ambient humidity grams water vapor per 

kilogram dry air

g H2O vapor/kg dry 

air

g H2O vapor/kg dry 

air

h change in height meters m m

I inertia pound mass or kilogram lbm or kg kg

I current ampere A A

i indexing variable

IR inertia work rating

K correction factor 1

Kv calibration coefficient m

4

∙s∙K0.5/kg m

4

∙s∙K0.5∙kg-1

 viscosity, dynamic pascal second Pa∙s m

-1

∙kg∙s-1

M molar mass gram per mole g/mol 10-3∙kg∙mol-1

Me effective mass kilogram kg kg

m mass pound mass or kilogram lbm or kg kg

N total number in series

n total number of pulses in a series

p pressure pascal Pa m

-1

∙kg∙s-2

p differential static pressure pascal Pa m

-1

∙kg∙s-2

pd

saturated vapor pressure at 

ambient dry bulb temperature kilopascal kPa m

-1

∙kg∙s-2

PF penetration fraction

Q flow cubic feet or cubic meter ft3or m3 m

3

Q flow rate cubic feet per minute or cubic 

meter per second ft3

/min or m3/s m

3

/s

ρ mass density kilogram per cubic meter kg/m3

kg∙m-3
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R dynamometer roll revolutions revolutions per minute rpm 2∙π∙60-1∙ m·m-1·s-1

r ratio of pressures pascal per pascal Pa/Pa 1

r

2

coefficient of determination

Re# Reynolds number

RF response factor

RH relative humidity

S Sutherland constant kelvin K K

SEE standard estimate of error

SG specific gravity

s

distance traveled during 

measurement interval meters m m

T absolute temperature kelvin K K

T Celsius temperature degree Celsius °C K – 273.15

T torque (moment of force) newton meter N∙m m

2

∙kg∙s-2

t time second s s

Δt time interval, period, 1/frequency second s s

U voltage volt V m

2

∙kg∙s-3∙A-1

v speed miles per hour or meters per 

second mph or m/s m∙s-1

V volume cubic meter m

3 m3

VP volume percent

x

concentration of emission over a 

test interval part per million ppm

y generic variable

Z compressibility factor Z

compressibility 

factor Z

(b) Symbols for chemical species. This part uses the following symbols for chemical 

species and exhaust constituents:

Symbol Species

CH4 methane

CH3OH methanol

CH2O formaldehyde

C2H4O acetaldehyde

C2H5OH ethanol

C2H6 ethane

C3H7OH propanol

C3H8 propane

C4H10 butane

C5H12 pentane

CO carbon monoxide

CO2 carbon dioxide

H2O water

HC hydrocarbon

N2 molecular nitrogen

NMHC nonmethane hydrocarbon

NMHCE nonmethane hydrocarbon equivalent

NMOG nonmethane organic gas

NO nitric oxide

NO2 nitrogen dioxide

NOx oxides of nitrogen

N2O nitrous oxide

O2 molecular oxygen

OHC oxygenated hydrocarbon

PM particulate matter
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THC total hydrocarbon

THCE total hydrocarbon equivalent

(c) Superscripts. This part uses the following superscripts to define a quantity:

Superscript Quantity

overbar (such as y ) arithmetic mean

overdot (such as y ) quantity per unit time

(d) Subscripts. This part uses the following subscripts to define a quantity:

Subscript Quantity

0 reference

abs absolute quantity

AC17 air conditioning 2017 test interval

act actual or measured condition

actint actual or measured condition over the speed interval

adj adjusted

air air, dry

atmos atmospheric

b base

bkgnd background

c cold

comp composite

cor corrected

cs cold stabilized

ct cold transient

cUDDS cold-start UDDS

D driven

dew dewpoint

dexh dilute exhaust quantity

dil dilute

e effective

emission emission specie

error error

EtOH ethanol

exh raw exhaust quantity

exp expected quantity

fil filter

final final

flow flow measurement device type

gas gaseous

h hot

HFET highway fuel economy test 

hs hot stabilized

ht hot transient

hUDDS hot-start UDDS

i an individual of a series

ID driven inertia

in inlet

int intake

init initial quantity, typically before an emission test

IT target inertia

liq liquid
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max

the maximum (i.e. peak) value expected at the standard over a test 

interval; not the maximum of an instrument range

meas measured quantity

mix dilute exhaust gas mixture

out outlet

PM particulate matter

record record

ref reference quantity

rev revolution

roll dynamometer roll

s settling

s slip

s stabilized

sat saturated condition

SC03 air conditioning driving schedule

span span quantity

sda secondary dilution air

std standard conditions

T target

t throat

test test quantity

uncor uncorrected quantity

w weighted

zero zero quantity

(e) Other acronyms and abbreviations. This part uses the following additional 

abbreviations and acronyms: 

A/C air conditioning

AC17 air conditioning 2017 test interval

ALVW adjusted loaded vehicle weight

ASME American Society of Mechanical Engineers

CFR Code of Federal Regulations

CFV critical-flow venturi

CNG compressed natural gas

CVS constant-volume sampler

EPA Environmental Protection Agency

ETW equivalent test weight

EV electric vehicle

FID flame-ionization detector

FTP Federal test procedure

GC gas chromatograph

GEM greenhouse gas emissions model

GHG greenhouse gas (including CO2, N2O, and CH4)

GPS global positioning system

GVWR gross vehicle weight rating

HEV hybrid electric vehicle, including plug-in hybrid electric 

vehicles

HFET highway fuel economy test

HLDT heavy light-duty truck

HPLC high pressure liquid chromatography

IBR incorporated by reference

LA-92 Los Angeles 1992 driving schedule

MDPV medium-duty passenger vehicle

NIST National Institute for Standards and Technology

NMC nonmethane cutter
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PDP positive-displacement pump

PHEV plug-in hybrid electric vehicle

PM particulate matter

RESS rechargeable energy storage system

ppm parts per million

SAE Society of Automotive Engineers

SC03 air conditioning driving schedule

SEA selective enforcement audit

SFTP supplemental federal test procedure

SI International System of Units

SSV subsonic venturi

UDDS urban dynamometer driving schedule

US06 aggressive driving schedule

U.S.C. United States Code

WWV NIST radio station call sign

(f) This part uses the following densities of chemical species:

Symbol Quantity1,2 g/m3g/ft3

ρCH4 density of methane 666.905 18.8847

ρCH3OH density of methanol 1332.02 37.7185

ρC2H5OH C1-equivalent density of ethanol 957.559 27.1151

ρC2H4O C1-equivalent density of acetaldehyde 915.658 25.9285

ρC3H8 density of propane 611.035 17.3026

ρC3H7OH C1-equivalent density of propanol 832.74 23.5806

ρCO density of carbon monoxide 1164.41 32.9725

ρCO2 density of carbon dioxide 1829.53 51.8064

ρHC-gas effective density of hydrocarbon - gaseous fuel3(see 3) (see 3)

ρCH2O density of formaldehyde 1248.21 35.3455

ρHC-liq effective density of hydrocarbon - liquid fuel4576.816 16.3336

ρNMHC-gas effective density of nonmethane hydrocarbon - gaseous fuel3(see 3) (see 3)

ρNMHC-liq effective density of nonmethane hydrocarbon - liquid fuel4576.816 16.3336

ρNMHCE-gas effective density of nonmethane equivalent hydrocarbon -

gaseous fuel3 (see 3) (see 3)

ρNMHCE-liq effective density of nonmethane equivalent hydrocarbon -

liquid fuel4 576.816 16.3336

ρNOx effective density of oxides of nitrogen51912.5 54.156

ρN2O density of nitrous oxide 1829.66 51.8103

ρTHC-liq effective density of total hydrocarbon - liquid fuel4576.816 16.3336

ρTHCE-liq effective density of total equivalent hydrocarbon - liquid fuel4576.816 16.3336

1Densities are given at 20 °C and 101.325 kPa.

2Densities for all hydrocarbon containing quantities are given in g/m3

-carbon atom and g/ft3-

carbon atom.

3The effective density for natural gas fuel and liquefied petroleum gas fuel are defined by an 

atomic hydrogen-to-carbon ratio, , of the hydrocarbon components of the test fuel. ρHCgas = 

41.57∙(12.011 + (∙1.008)).

4The effective density for gasoline and diesel fuel are defined by an atomic hydrogen-to-carbon 

ratio, , of 1.85.

5The effective density of NOx

is defined by the molar mass of nitrogen dioxide, NO2.

(g) Constants. (1) This part uses the following constants for the composition of dry air:

Symbol Quantity mol/mol 

xArair amount of argon in dry air 0.00934

xCO2air amount of carbon dioxide in dry air 0.000375

xN2air amount of nitrogen in dry air 0.78084
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xO2air amount of oxygen in dry air 0.209445

(2) This part uses the following molar masses or effective molar masses of chemical 

species:

Symbol Quantity g/mol

(10-3·kg·mol-1)

Mair molar mass of dry air128.96559

MH2O molar mass of water 18.01528

1

See paragraph (g)(1) of this section for the composition of dry air.

(3) This part uses the following molar gas constant for ideal gases:

Symbol Quantity J/(mol∙K)

(m2∙kg∙s-2∙mol-1∙K-1)

R molar gas constant 8.314472

(h) Prefixes. This part uses the following prefixes to define a quantity:

Symbol Quantity Value

 micro 10-6

m milli 10-3

c centi 10-2

k kilo 103

M mega 106

n nano 10-9

§ 1066.1010 Incorporation by reference.

(a) Certain material is incorporated by reference into this part with the approval of the 

Director of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. To enforce any 

edition other than that specified in this section, a document must be published in the 

Federal Register and the material must be available to the public. All approved material 

is available for inspection at U.S. EPA, Air and Radiation Docket and Information 

Center, 1301 Constitution Ave., NW., Room B102, EPA West Building, Washington, 

DC 20460, (202) 202-1744, and is available from the sources listed below. It is also 

available for inspection at the National Archives and Records Administration (NARA). 

For information on the availability of this material at NARA, call 202–741–6030, or go to 

http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

To enforce any edition other than that specified in this section, a document must be 

published in the Federal Register and the material must be available to the public.

(b) SAE International material. The following standards are available from SAE 

International, 400 Commonwealth Dr., Warrendale, PA 15096–0001, (877) 606–7323 

(U.S. and Canada) or (724) 776–4970 (outside the U.S. and Canada), or 

http://www.sae.org: 

(1) SAE J1263, Road Load Measurement and Dynamometer Simulation Using 

Coastdown Techniques, revised March 2010, IBR approved for §§ 1066.301(b), 

1066.305, and 1066.310(b).

(2) SAE J1634, Battery Electric Vehicle Energy Consumption and Range Test Procedure, 

revised October 2012, IBR approved for § 1066.501(a).
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 1039 of 1039

(3) SAE J1711, Recommended Practice for Measuring the Exhaust Emissions and Fuel 

Economy of Hybrid-Electric Vehicles, Including Plug-In Hybrid Vehicles, revised June 

2010, IBR approved for §§ 1066.125 and 1066.501(a).

(4) SAE J2263, Road Load Measurement Using Onboard Anemometry and Coastdown 

Techniques, revised December 2008, IBR approved for §§ 1066.301(b), 1066.305, and 

1066.310(b).

(5) SAE J2264, Chassis Dynamometer Simulation of Road Load Using Coastdown 

Techniques, revised January 2014, IBR approved for § 1066.315.

(6) SAE J2711, Recommended Practice for Measuring Fuel Economy and Emissions of 

Hybrid-Electric and Conventional Heavy-Duty Vehicles, issued September 2002, IBR 

approved for § 1066.501(a).

(7) SAE J2951, Drive Quality Evaluation for Chassis Dynamometer Testing, revised 

January 2014, IBR approved for § 1066.425(j).

(c) National Institute of Standards and Technology material. The following documents 

are available from National Institute of Standards and Technology, 100 Bureau Drive, 

Stop 1070, Gaithersburg, MD 20899-1070, (301) 975-6478, or www.nist.gov:

(1) NIST Special Publication 811, 2008 Edition, Guide for the Use of the International 

System of Units (SI), Ambler Thompson and Barry N. Taylor, Physics Laboratory, 

March 2008, IBR approved for §§ 1066.20(a) and 1066.1005.

(2) [Reserved]