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EO 12866 _Tier_3_2060-AQ86_NPRM_FRN_20130325_tracked.doc

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 79, 80, 85, 86, 600, 1036, 1037, 1065, and 1066

[EPA–HQ–OAR–2011–0135; FRL_XXXX-X]

RIN 2060-AQ86

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

Fuel Standards

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed Rule.

SUMMARY: This action would establish more stringent vehicle emissions standards and 

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 

proposed gasoline sulfur standard would make emission control systems more effective 

for both existing and new vehicles, and would enable more stringent vehicle emissions 

standards. The proposed vehicle standards would reduce both tailpipe and evaporative 

emissions from passenger cars, light-duty trucks, medium-duty passenger vehicles, and 

some heavy-duty vehicles. This would 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 proposed vehicle standards are intended to harmonize 

with California’s Low Emission Vehicle program, thus creating a federal vehicle 

emissions program that would allow automakers to sell the same vehicles in all 50 states. 

The proposed vehicle standards would be implemented over the same timeframe as the 

greenhouse gas/fuel efficiency standards for light-duty vehicles, as part of a 

comprehensive approach toward regulating emissions from motor vehicles. 

DATES: EPA will announce the comment period and the public hearing dates for this 

proposal in a supplemental Federal Register Notice. Under the Paperwork Reduction 

Act, comments on the information collection provisions are best assured of having full 

effect if the Office of Management and Budget (OMB) receives a copy of your comments 

on or before [insert date 30 days after publication in the federal register], thirty days 

after date of publication in the Federal Register.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA–HQ–OAR–

2011–0135, by one of the following methods:

 www.regulations.gov: Follow the on-line instructions for submitting 

comments.
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 Email: A-and-R-Docket@epamail.epa.gov.

 Mail: Air and Radiation Docket and Information Center, Environmental 

Protection Agency, Mailcode: 2822T, 1200 Pennsylvania Ave., NW., 

Washington, DC 20460. In addition, please mail a copy of your comments on 

the information collection provisions to the Office of Information and 

Regulatory Affairs, Office of Management and Budget (OMB), Attn: Desk 

Officer for EPA, 725 17th St. NW., Washington, DC 20503.

 Hand Delivery: EPA Docket Center, EPA West Building, Room 3334, 1301 

Constitution Ave., NW., Washington, DC 20460. Such deliveries are only 

accepted during the Docket’s normal hours of operation, and special 

arrangements should be made for deliveries of boxed information.

Instructions: Direct your comments to Docket ID No. EPA–HQ–OAR–2011–0135. 

EPA's policy is that all comments received will be included in the public docket without 

change and may be made available online at www.regulations.gov, including any 

personal information provided, unless the comment includes information claimed to be 

Confidential Business Information (CBI) or other information whose disclosure is 

restricted by statute. Do not submit information that you consider to be CBI or otherwise 

protected through www.regulations.gov or e-mail. The www.regulations.gov website is 

an “anonymous access” system, which means EPA will not know your identity or contact 

information unless you provide it in the body of your comment. If you send an e-mail 

comment directly to EPA without going through www.regulations.gov your e-mail 

address will be automatically captured and included as part of the comment that is placed 

in the public docket and made available on the Internet. If you submit an electronic 

comment, EPA recommends that you include your name and other contact information in 

the body of your comment and with any disk or CD-ROM you submit. If EPA cannot 

read your comment due to technical difficulties and cannot contact you for clarification, 

EPA may not be able to consider your comment. Electronic files should avoid the use of 

special characters, any form of encryption, and be free of any defects or viruses. For 

additional information about EPA’s public docket visit the EPA Docket Center homepage 

at http://www.epa.gov/epahome/dockets.htm. For additional instructions on submitting 

comments, go to Section I.B of the SUPPLEMENTARY INFORMATION section of 

this document.

Docket: All documents in the docket are listed in the www.regulations.gov index. 

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, will be publicly available only in hard copy. Publicly available 

docket materials are 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.
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FOR FURTHER INFORMATION CONTACT: Julia MacAllister, Office of 

Transportation and Air Quality, Assessment and Standards Division, Environmental 

Protection Agency, 2000 Traverwood Drive, Ann Arbor MI 48105; Telephone number: 

(734) 214-4131; Fax number: (734) 214-4816; E-mail address: 

macallister.julia@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

Entities potentially affected by this proposed rule include gasoline refiners and 

importers, ethanol 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 manufacturers

Industry 325193 2869 Ethyl alcohol manufacturing

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. E51-83 

manufacturers.

Industry 493190

4226

Other warehousing and storage- bulk petroleum 

storage

Industry 336111,

336112 3711

Light-duty vehicle and light-duty truck 

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, 3699, On-highway heavy-duty engine & vehicle 
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336120,

336211,

336312

3711, 

3713, 

3714

(>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 proposed action. This table lists the types 

of entities that EPA is now aware could potentially be regulated by this proposed action. 

Other types of entities not listed in the table could also be regulated. To determine 

whether your activities would be regulated by this proposed action, you should carefully 

examine the applicability criteria in 40 CFR parts 79, 80, 85, 86, 1065, and 1066 and the 

referenced regulations. If you have any questions regarding the applicability of this 

proposed action to a particular entity, consult the person listed in the preceding FOR 

FURTHER INFORMATION CONTACT section.

B. What Should I Consider as I Prepare My Comments for EPA?

1. Submitting CBI.

Do not submit this information to EPA through www.regulations.gov or e-mail. 

Clearly mark the part or all of the information that you claim to be CBI. For CBI 

information in a disk or CD ROM that you mail to EPA, mark the outside of the disk or 

CD ROM as CBI and then identify electronically within the disk or CD ROM the specific 

information that is claimed as CBI. In addition to one complete version of the comment 

that includes information claimed as CBI, a copy of the comment that does not contain 

the information claimed as CBI must be submitted for inclusion in the public docket. 

Information so marked will not be disclosed except in accordance with procedures set 

forth in 40 CFR part 2.

2. Tips for Preparing Your Comments.

When submitting comments, remember to:

 Identify the rulemaking by docket number and other identifying information 

(subject heading, Federal Register date and page number).

 Follow directions - The agency may ask you to respond to specific questions 

or organize comments by referencing a Code of Federal Regulations (CFR) 

part or section number.

 Explain why you agree or disagree, suggest alternatives, and substitute 

language for your requested changes.

 Describe any assumptions and provide any technical information and/or data 

that you used.
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 If you estimate potential costs or burdens, explain how you arrived at your 

estimate in sufficient detail to allow for it to be reproduced.

 Provide specific examples to illustrate your concerns, and suggest alternatives.

 Explain your views as clearly as possible, avoiding the use of profanity or 

personal threats.

 Make sure to submit your comments by the comment period deadline 

identified.

C. Did EPA Conduct a Peer Review before Issuing this Notice?

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. Specifically, EPA conducted six peer reviews in 

connection with data supporting the proposed 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 Overview of Proposed Program

A. Introduction

B. What Are the Basic Components of the Proposed Program?

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

2. Proposed Heavy-Duty Vehicle Tailpipe Emissions Standards

3. Proposed Evaporative Emission Standards

4. Onboard Diagnostic Systems (OBD)

5. Emissions Test Fuel

6. Fuel Standards

7. Regulatory Streamlining and Technical Amendments

C. What Would the Impacts of the Proposed Standards Be?

II. Why is EPA Making This Proposal?

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. Nitrogen Oxides and Sulfur Oxides

4. Carbon Monoxide

5. Mobile Source Air Toxics

6. Near-Roadway Pollution
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7. Environmental Impacts of Motor Vehicles and Fuels

III. How Would This Proposal Reduce Emissions and Air Pollution?

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

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

2. How Would the Proposed Changes to Gasoline Sulfur Content Affect Vehicle 

Emissions?

B. How Would Emissions Be Reduced?

1. NOX

2. VOC

3. CO

4. Direct PM2.5

5. Air Toxics

6. SO2

7. Greenhouse Gases

C. How Would Air Pollution Be Reduced?

1. Ozone

2. Particulate Matter

3. Nitrogen Dioxide

4. Air Toxics

5. Visibility

6. Nitrogen and Sulfur Deposition

7. Environmental Justice

IV. Proposed Vehicle Emissions Program

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

Medium-Duty Passenger Vehicles

1. Overview

2. Summary of Proposed FTP and SFTP Tailpipe Standards

3. Proposed FTP Standards

4. Proposed SFTP Standards

5. Feasibility of the Proposed NMOG+NOX and PM Standards

6. Impact of Gasoline Sulfur Control on the Feasibility of the Proposed Vehicle 

Emission Standards

7. Other Provisions

B. Tailpipe Emissions Standards for Heavy-Duty Vehicles

1. Overview

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 and Onboard Diagnostic System Requirements

1. Tier 3 Evaporative Emission Standards

2. Evaporative Emissions Program Structure and Implementation Flexibilities

3. Heavy-Duty Gasoline Vehicle (HDGV) Requirements

4. Test Procedures and Certification Test Fuel

5. Improvements to In-Use Performance of Fuel Vapor Control Systems
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6. Other Initiatives

D. Emissions Test Fuel

1. Proposed Changes to Gasoline Emissions Test Fuel

2. Proposed Flexible Fuel Vehicle Test Fuel

3. Proposed Implementation Schedule

4. Potential Implications on CAFE Standards, GHG Standards, and Fuel 

Economy Labels

5. Consideration of Nonroad, Motorcycle, and Heavy-Duty Engine Emissions 

Test Fuel

6. Consideration of CNG and LPG Emissions Test Fuels

E. Small-Business Provisions

1. Lead Time for Exhaust and Evaporative Emission Standards

2. Assigned Deterioration Factors

3. Reduced Testing Burden

4. Hardship

5. Applicability of Flexibilities

F. Compliance Provisions

1. Exhaust Emission Test Procedures

2. Reduced Test Burden

3. Miscellaneous Provisions

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

V. Proposed Fuel Program

A. Proposed Tier 3 Gasoline Sulfur Standards

1. Overview

2. Proposed Annual Average Sulfur Standard

3. Per-Gallon Sulfur Caps

B. Refinery Air Permitting Interactions

1. Background on New Source Review Programs

2. Background on NSR Experience Under the Tier 2 Fuel Program

3. Changes in the NSR Permitting Program since Tier 2 Final Rule

4. Assessment of Tier 3 Refinery Changes and Permitting Implications

5. Proposed New Source Performance Standards and Proposed National 

Emission Standards for Hazardous Air Pollutants for Refineries

6. Possible Steps for Addressing Permitting Roadblocks

C. Standards for Denatured Fuel Ethanol and Other Oxygenates

D. Standards for Fuel Used in Flexible Fueled Vehicles

1. Standards for E51-83

2. Standards for Mid-Level Ethanol Blends (E16-50)

E. Proposed Program Flexibilities

1. Averaging, Banking, and Trading Program

2. Regulatory Flexibility Provisions

3. Provisions for Refiners Facing Hardship Situations

F. Compliance Provisions

1. Registration, Reporting, and Recordkeeping Requirements

2. Sampling and Testing Requirements

3. Small Refiner Compliance
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4. Small Volume Refinery Compliance

5. Attest Engagements, Violations, and Penalties

6. Special Fuel Provisions and Exemptions

G. Statutory Authority for Proposed Tier 3 Fuel Controls

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

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

VI. Technical Amendments and Regulatory Streamlining

A. Amendments to 40 CFR Part 80

1. Regulatory Streamlining

2. Subpart I Technical Amendments

3. Performance-Based Measurement Systems (PBMS)

4. Downstream Pentane Blending

B. Engine, Vehicle and Equipment Programs

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 Proposed Rule?

A. Estimated Costs of the Vehicle Standards

B. Estimated Costs of the Fuel Program

1. Overview

2. Methodology

3. Summary of Costs without ABT Program

4. Summary of Costs with ABT Program

5. Other Cost Estimates

C. Summary of Proposed Program Costs

D. Cost per Ton of Emissions Reduced

VIII. What are the Estimated Benefits of the Proposed Rule?

A. Overview

B. Quantified Human Health Impacts

C. Monetized Benefits

D. What are the Limitations of the Benefits Analysis?

E. Illustrative Analysis of Monetized Impacts Associated with the Proposal in 2017

IX. Alternatives Analysis

A. Vehicle Emission Standards

1. Shorter NMOG+NOX Standard Phase-in

2. Longer NMOG+NOX Standards Phase-in Due to Early Credits

3. Shorter PM Standards Phase-in

4. NMOG+NOX Standards

5. PM Standards

B. Fuel Sulfur Standards

X. Economic Impact Analysis

A. Introduction

B. Vehicle Sales Impacts

C. Impacts on Petroleum Refinery Sector Production

D. Employment Impacts
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1. Employment Impacts in the Auto Sector

2. Refinery Employment Impacts

XI. Public Participation

A. How Do I Submit Comments?

B. How Should I Submit CBI to the Agency?

C. Will There Be a Public Hearing?

D. Comment Period

E. What Should I Consider as I Prepare My Comments for EPA?

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

3. Reason for Today’s Proposed Rule

4. Legal Basis for Agency Action

5. Summary of Potentially Affected Small Entities

6. Potential Reporting, Recordkeeping, and Compliance

7. Related Federal Rules

8. Summary of SBREFA Panel Process and Panel Outreach

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

XIII. Statutory Provisions And Legal Authority

I. Executive Summary and Overview of Proposed Program 

A. Introduction

In this action, EPA is proposing 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 proposed program as the “Tier 3” vehicle and fuel 

standards. 
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This proposed rule is part of a comprehensive approach to address the impacts of 

motor vehicles on air quality and public health. Over 158 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 

mortality.

1

 Motor vehicles are a particularly important source of exposure to air 

pollution, especially in urban areas. By 2014 we project that in many nonattainment 

areas, cars and light trucks will contribute 30-45 percent of total nitrogen oxides (NOX) 

emissions, 20-25 percent of total volatile organic compound (VOC) emissions, and 5-10 

percent of total direct particulate matter (PM2.5) emissions.2These 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 Almost 90 percent of daily trips use personal vehicles.6

The standards set forth in this proposed rule would 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 impacts expected 

due to the proposed sulfur control standards starting in 2017. These reductions would 

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 would 

deliver the same magnitude of multi-pollutant reductions projected to result from the 

proposed Tier 3 standards. In the absence of additional controls such as the Tier 3 

 

1 Data come from Summary Nonattainment Area Population Exposure Report, current as of December 14, 

2012 at: http://www.epa.gov/oar/oaqps/greenbk/popexp.html and contained in Docket EPA-HQ-OAR2011-0135.

2 Mobile source contributions derived from inventories developed for the 2011 Cross –State Air pollution 

Transport Rule. For more information on these inventories see the “Technical Support Document (TSD) 

for the final Transport Rule, Docket ID No. EPA-HQ-OAR-2009-0491, Emissions Inventory Final Rule 

TSD,” available on the web at 

ftp://ftp.epa.gov/EmisInventory/2005v4_2/transportrulefinal_eitsd_28jun2011.pdf .

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 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/
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standards, five counties will continue to have ambient ozone concentrations exceeding 

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

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 proposing represent a “systems 

approach” to reducing vehicle-related 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 proposed Tier 3 standards would be a cost-effective way to 

achieve substantial additional emissions reductions. 

The proposed 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 evaporative emissions standards. The 

proposed 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 proposed Tier 3 heavy-duty vehicle tailpipe emissions standards provide reductions 

in both NMOG+NOX and PM that are on the order of 60 percent, compared to current

standards. The proposed evaporative emissions standards represent a 50 percent reduction 

from current standards.

The vehicle emission standards, combined with the proposed reduction of 

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

ppm average, would 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 would 

make up the majority of the fleet as well as vehicle miles travelled, NOX and VOC 

emissions from on-highway vehicles would be reduced by about one quarter, and CO 

emissions would be reduced by about 30 percent. Emissions of many air toxics would 

also be reduced by 10 to nearly 40 percent of national emissions from on-highway

vehicles. Reductions would continue beyond 2030 as more of the fleet is composed of 

Tier 3 vehicles. For example, the Tier 3 program would reduce on-highway emissions of 

NOX and VOC nearly 40 percent by 2050, when Tier 3 vehicles would comprise almost 

the entire fleet.

 

7

65 FR 6698 (February 10, 2000)
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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 

volatile hydrocarbon fraction), CO, and most air toxics. The catalytic converters become 

significantly less efficient when sulfur from the gasoline is deposited (adsorbed) onto the 

precious metals that catalyze the reactions to reduce the emissions. 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 proposed Tier 

3 standards. Thus, the proposed Tier 3 10-ppm average sulfur standard is significant in 

two ways: it enables vehicles designed to the proposed 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 sulfur 

controls are implemented. Lower sulfur gasoline also facilitates the development of 

lower-cost technologies to improve fuel economy. Sulfur in the fuel quickly causes the 

fuel economy benefits of lean-burn technologies to disappear due to its effect on NOx 

adsorber operation requiring more fuel to be burned. We are 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 proposal is one aspect of a comprehensive national program regulating 

emissions from motor vehicles. EPA’s recent 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 proposal 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 proposed Tier 3 standards are 

also closely coordinated with California’s Low Emission Vehicle (LEV III) program to 

create a vehicle emissions program that would allow automakers to sell the same vehicles 

in all 50 states. (In December 2012, EPA granted approval of the California Air 

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

states have 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, 

 

8

77 FR 62623 (October 15, 2012).

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

Pennsylvania, Rhode Island, Washington, and Vermont.
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who have emphasized the importance of a harmonized national program. Together, the 

Tier 3, 2017 LD GHG, and LEV III standards would maximize reductions in GHGs, 

criteria pollutants and air toxics from motor vehicles while streamlining programs and 

requiring manufacturers to design a single vehicle for nationwide sales. In this way, the 

Tier 3 proposal 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 are considering the future 

fuels on which vehicles will be operating. 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 will result in 

significant amounts of ethanol-blended gasoline in the implementation timeframe of the 

proposed Tier 3 program. We are proposing to update the specifications of the 

certification test fuel with which vehicles demonstrate compliance with emissions 

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

that will be in use.

This section provides an overview of the vehicle- and fuel-related standards we 

are proposing as well as the impacts of the proposed standards. The public health issues 

and statutory requirements that have prompted this proposal are described in Section II, 

and our discussion of how the proposal would reduce emissions and air pollution is 

presented in Section III. Details of proposed standards and how they would be 

implemented can be found in Sections IV through VI. Sections VII through X contain 

our discussion of the proposed standards’ technological feasibility and cost, benefits, 

alternatives and economic impacts.

B. What Are the Basic Components of the Proposed Program?

In the more than 10 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 key exhaust emissions, especially VOC, NOX, and PM. 

The California LEV II program has been instrumental in the continuous technology

improvements by requiring year after year reductions in the fleet average hydrocarbon 

levels, in addition to requiring the introduction of advanced exhaust and evaporative 

emission controls in partial zero emission vehicles (PZEVs). This progress in vehicle 

technology 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, we are proposing new standards for exhaust emissions of NMOG, 

NOX, and PM, as well as evaporative emissions standards. These standards would phase 

 

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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in beginning with MY 2017. The proposed Tier 3 standards are very similar in structure 

to those in the existing Tier 2 program. As with the Tier 2 program, the proposed 

standards would apply to all light-duty vehicles (LDVs, or passenger cars), light-duty

trucks (LDT1s, LDT2s, LDT3s, and LDT4s) and Medium-Duty Passenger Vehicles (or 

MDPVs). We are also proposing separate but closely related standards for heavy-duty 

vehicles up to 14,000 lbs Gross Vehicle Weight Rating (GVWR). These vehicles were 

not included in Tier 2 but were made subject to new standards in a final rule that covered 

the broad heavy-duty sector (66 FR 5002, January 18, 2001). We have concluded that the 

proposed vehicle emissions standards, in conjunction with the reductions in fuel sulfur 

also proposed in this action, are feasible across the fleet in the proposed time frame. 

In the discussions of the various elements of our proposed program for light- and 

heavy-duty vehicles throughout this preamble, we describe how the provisions would be 

consistent with the California Air Resources Board (CARB) LEV III program. Auto 

manufacturers have stressed to us the importance of their being able to design and 

produce a single fleet of vehicles in all 50 states that would comply with requirements 

under the Tier 3 program and the LEV III program, as well as greenhouse gas/Corporate 

Average Fuel Economy (CAFE) requirements in the same timeframe. Consistency

among the federal and California programs means that special versions of vehicles with 

different emission control hardware and calibrations would not be necessary for different 

geographic areas. This would allow manufacturers to avoid the additional costs of 

parallel design, development, calibration, and manufacturing. Consistency among 

programs would also eliminate the need to supply aftermarket parts for repair of multiple 

versions of a vehicle. To that end, we worked closely with CARB and with the vehicle 

manufacturers, both with individual companies and with their trade associations, to align 

the two programs in most respects. 

We have also designed the proposed Tier 3 program to be implemented in the 

same timeframe as the federal and California 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 would phase in over the same timeframe, manufacturers 

would be in a position to simultaneously respond to all of these requirements.

1. Proposed Tailpipe Standards for Light-Duty Vehicle, Light-Duty Truck, and 

Medium-Duty Passenger Vehicle Tailpipe Emissions

We are proposing a comprehensive program that would include new fleet-average

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

and for PM.12 These proposed standards, when applied in conjunction with reduced 

gasoline sulfur content, would result in very significant improvements in vehicle 

emissions from the levels of the Tier 2 program. For these pollutants, we are proposing 

 

12A discussion of the reasons for combining the two pollutants for this purpose is in Section IV.A.3.a 

below.
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standards as 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 

temperatures, higher speeds, and quicker accelerations). In addition to the standards, we 

are also proposing to extend the regulatory useful life period during which the standards 

apply and to make test fuel more representative of expected real-world fuel (see Section 

I.B.5 below).

As discussed in Section IV.A.6., the impact of gasoline sulfur poisoning on 

exhaust catalyst performance provides a compelling argument, particularly for larger 

vehicles and trucks, that these vehicle standards would be achievable only with a 

reduction of gasoline sulfur content from the current 30-ppm average down to a 10-ppm 

average. 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 proposed new stringent standards, the manufacturer’s ability to 

maintain the emission performance of that vehicle in-use can be greatly jeopardized if the 

vehicle is being operated on gasoline sulfur levels greater than 10 ppm. Vehicle 

manufacturers, both individually and through their trade associations, have emphasized 

that reduced gasoline sulfur would be required to meet the proposed standards.13,14 Due 

to the variation in actual vehicle operation, any amount of gasoline sulfur will deteriorate 

catalyst efficiency. However, we believe that a 10-ppm average sulfur level is 

sufficiently low to enable compliance with these proposed Tier 3 vehicle standards, and 

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

control costs to quickly escalate. Because of the complexity of sulfur’s interactions with 

catalyst materials, we are seeking further information and data on the relationship 

between gasoline sulfur levels and catalyst effectiveness.

The proposed FTP and SFTP NMOG+NOX standards would be fleet-average 

standards, meaning that a manufacturer would calculate the average emissions of the 

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

for that model year. The manufacturer would certify each of its vehicles to a per-vehicle 

“bin” standard (see Section IV.A.2) and sales-weight these values to calculate its fleetaverage NMOG+NOX emissions for each model year. The proposed fleet average 

standards for NMOG+NOX evaluated over the FTP are summarized in Table I-1. The 

standards for light-duty vehicles would begin in MY 2017 at a level representing a 46 

percent reduction from the current Tier 2 requirements. (For vehicles over 6000 lbs

GVWR, the standards would apply beginning in MY 2018). As shown, these proposed 

fleet-average standards would decline during the first several years of the program, 

becoming increasingly stringent until ultimately reaching an 81 percent reduction when 

the transition is complete. The proposed FTP NMOG+NOX program includes two 

 

13 Letter to EPA Administrator Jackson, with white paper, from Alliance of Automobile Manufacturers, 

October 6, 2011.

14 Global Automakers letter to EPA Administrator Jackson, October 21, 2011.
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separate sets of declining fleet-average standards, with LDVs and small light trucks 

(LDT1s) in one grouping and heavier light trucks (LDT2s, LDT3s, LDT4s) and MDPVs 

in a second grouping, that would converge at 30 milligram per mile (mg/mi) in MY 2025 

and later.16

Manufacturers could also earn credits for fleet average NMOG+NOX levels below 

the applicable standard in any model year. Credits that were previously banked or 

obtained from other manufacturers could be used, or credits could be transferred to other 

manufacturers (see Section IV.A.7.a). Unused credits would expire after 5 model years. 

Manufacturers would also be allowed to carry deficits in their credit balance for up to 3 

model years.

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

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 vehicles above 6000 lbs GVWR, the fleet average standards would apply beginning in MY 2018.

b These proposed standards would apply for a 150,000 mile useful life. Manufacturers could choose to 

certify all of their LDVs and LDT1s to a useful life of 120,000 miles. If any of these families are certified 

to the shorter useful life, a proportionally lower numerical fleet-average standard would apply, calculated 

by multiplying the respective 150,000 mile standard by 0.85 and rounding to the nearest mg. See Section 

IV.A.7.b.

Similarly, the proposed NMOG+NOX standards measured over the SFTP would 

be fleet-average standards, declining from MY 2017 until MY 2025, as shown in Table 

I-2. In this case, the same standards would apply to both lighter and heavier vehicles. In 

MY 2025, the SFTP NMOG+NOX standard would reach its final fleet average level of 50 

mg/mi.

 

16 Alternatively, a manufacturer could choose to certify its entire fleet of passenger cars and light trucks to 

the 30 mg/mi level beginning in MY 2017 and continuing for all subsequent model years. A percent phasein would apply. This would not be a fleet-average standard. 
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Table I-2 Proposed LDV, LDT, and MDPV Fleet Average NMOG+NOX SFTP

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 vehicles above 6000 lbs GVWR, the fleet average standards would apply beginning in MY 2018. 

We are also proposing PM standards as part of this Tier 3 program, both on the 

FTP and US06 cycles (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.17 Although many vehicles today are performing at or near the 

levels of the proposed standards, the data indicate that improvements, especially in highload 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, we are 

proposing a new FTP PM standard that is set to ensure that all new vehicles perform at 

the level already being achieved by well-designed Tier 2 emission control technologies. 

The proposed PM standards would apply to each vehicle separately (i.e., not as a fleet 

average). Also, in contrast to the declining NMOG+NOX standards, the proposed 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 would apply beginning in MY 2018. Manufacturers could 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 proposed standard is 

to bring all light-duty vehicles to the typical level of PM performance being demonstrated 

by the current light-duty fleet. 

The proposed program also includes a separate in-use FTP PM standard of 6 

mg/mi for the testing of in-use vehicles that would apply during the percent phase-in 

period only. This in-use standard would address the uncertainties that accompany the 

introduction of new technologies, and then expire. Table I-3 presents the FTP 

certification and in-use PM standards and the phase-in percentages. The proposed 

standards represent a significant numerical reduction from the Tier 2 PM emission 

standards of 10 mg/mi for light-duty vehicles.

 

17 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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Table I-3 Phase-In for Proposed FTP PM Standards 

2017a2018 2019 2020 2021 2022 and 

later

Phase-In

(percent of U.S. sales)

20 20 40 70 100 100

Certification 

Standard (mg/mi)

3 3 3 3 3 3

In-Use Standard 

(mg/mi)

6 6 6 6 6 3

a

For vehicles above 6000 lbs GVWR, the proposed FTP PM standards would apply beginning in MY 

2018.

Finally, the proposed Tier 3 program includes certification PM standards 

evaluated over the SFTP (specifically the US06 component of the SFTP procedure) at a 

level of 10 mg/mi for lighter vehicles and 20 mg/mi for heavier vehicles. PM levels over 

the SFTP are typically higher than the PM emitted over the FTP due to the increased load 

on the vehicle. Test data show that most current light-duty vehicles are already 

performing in the range of the proposed standard. As in the case of the FTP PM 

standards, the intent of the proposed 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 with the FTP PM standard, we propose separate in-use US06 PM standards 

during the percent phase-in only, of 15 and 25 mg/mi for vehicles up to and above 6,000 

lbs (lbs) GVWR, respectively. The US06 PM standards would also phase in on the same 

schedule as the FTP PM standards, reaching 100 percent of each company’s U.S. sales by

MY 2022. 

2. Proposed Heavy-Duty Vehicle Tailpipe Emissions Standards

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

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

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

lb) and Class 3 (10,001-14,000 lb) vehicles, and are typically full-size pickup trucks and 

work vans. Most are built by companies with even larger light-duty truck markets, and as 

such they frequently share major design characteristics and potential emissions control 

technologies with their LDT counterparts. However, in contrast to the largely gasolinefueled LDT fleet, roughly half of the HD pickup and van fleet in the U.S. is diesel-fueled, 

which is a consideration in setting emissions standards, as diesel engine emissions and 

control strategies differ from those of gasoline engines.

The key elements of the proposed Tier 3 program for HDVs would parallel those 

proposed for passenger cars and 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, new 

stringent PM standards phasing in on a separate schedule, adoption of a 15 percent 

ethanol by volume (E15) certification test fuel for gasoline-fueled vehicles, extension of 
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the regulatory useful life to 150,000 miles or 15 years (whichever occurs first), and a new 

requirement to meet standards over an SFTP that would address real-world driving modes 

not well-represented by the FTP cycle alone.

We are proposing the separate Class 2b and Class 3 fleet average NMOG+NOX

standards shown in Table I-4. The proposed standards would become more stringent in 

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

2016 and 2017, all of which would be 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 would contribute to this fleet average based on the mg/mi NMOG+NOX

level of the emission level (“bin”) declared for it by the manufacturer. Manufacturers 

could 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 could be used to help 

demonstrate compliance. Unused credits would expire after 5 model years. 

Manufacturers would also be allowed to carry deficits in their credit balance for up to 3 

model years.

Table I-4 Proposed 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 are proposing 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 proposing the same phase-in schedule as proposed 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 proposed. Tier 3 

HDVs would also be subject to more stringent CO and formaldehyde exhaust emissions 

standards.

Finally, we are proposing first-ever 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 light-duty

vehicles, we are proposing 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-to-weight Class 2b 

HDVs, and the LA-92 (or “Unified”) cycle for Class 3 HDVs. The proposed SFTP 
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standards are the same as those adopted for California LEV III vehicles, and would apply

to NMOG+NOX, PM, and CO emissions.

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

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

The final Tier 3 standards levels for NMOG+NOX and PM are on the order of 60 percent 

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

3. Proposed 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. Even though evaporative 

and refueling emission control systems have been in place for most of these vehicles for 

many years, they still contribute about 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 proposing more stringent standards that 

would 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 a portion of heavy-duty gasoline vehicles (HDGVs) over 

10,000 lbs GVWR. EPA is proposing phase-in flexibilities as well as credit and 

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

standards, are designed to essentially 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 itself.

Requirements to meet the Tier 3 evaporative emission regulations would phase-in 

over a six model year period. We are proposing two 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 proposed evaporative diurnal plus hot soak 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 proposing a 

program that would allow manufacturers to generate allowances through early

certifications (basically before the 2017 model year) and to demonstrate compliance 
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using averaging concepts. Manufacturers may comply on average within each of the four 

vehicle categories, but not across these categories. EPA is not proposing 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.5 below.

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

Vehicle Class Highest Diurnal + Hot Soak 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

EPA is proposing a new testing requirement referred to as the bleed emission test 

procedure to help ensure fuel vapor emissions are eliminated. Under this proposal, 

manufacturers would be 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 would be 0.030 

g/test. The proposed Tier 3 evaporative emission standards would 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.

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 relatively significant contributions to the mobile source VOC 

inventory. To help address this issue, we are also proposing to add a new emission 

standard and test procedure to control vapor leaks from vehicle fuel and vapor control 

systems. The standard would prohibit leaks with a cumulative equivalent diameter of 

0.02 inches or greater. We are proposing to add 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 proposed Tier 3 evaporative emission regulations would also be 

required to meet the leak emission standard beginning in the 2018 model year. The 

requirement to meet the leak emission standard would phase-in on the same percentage of 

sales schedule as the proposed Tier 3 evaporative emission standard. Manufacturers 

would comply with the leak emission standard during certification and in use. EPA is not 

proposing that the leak emission standard apply to HDGVs above 14,000 lbs GVWR.

EPA is also proposing new refueling emission control requirements for all 

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

2018 model year. EPA is proposing to include these vehicles as part of the same basic 

implementation scheme used for LDVs and LDTs. The current refueling emission 

control requirements apply to complete Class 2b HDGVs, and EPA is proposing to 

extend those requirements to Class 3 HDGVs as well, since the fuel and evaporative 
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control systems on these vehicles are very similar to those on their slightly lighter-weight 

Class 2b counterparts. 

4. Onboard Diagnostic Systems (OBD)

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

covered by the proposed 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 proposing to adopt and incorporate by reference the current 

CARB OBD regulations effective for the 2017 MY. We are also proposing two specific 

additions to enhance the implementation of the leak emission standard. EPA would 

retain the provision that certifying with CARB’s program would permit manufacturers to 

seek a separate EPA certificate on that basis. 

5. Emissions Test Fuel

In-use gasoline has changed considerably since EPA’s test fuel specifications 

were first set and last revised. Gasoline sulfur and benzene have been reduced and, 

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

replaced clear gasoline (E0) across the country. This has had second-order effects on 

other gasoline properties. In-use fuel is projected to continue to change with the 

implementation of the RFS2 program (e.g., the expansion of the number of retailers that 

offer gasoline containing 15 percent ethanol by volume (E15)) as well as today’s 

proposed Tier 3 gasoline sulfur program. 

As a result, we are proposing to update our federal emissions test fuel to better 

match today’s in-use gasoline and also to be forward-looking with respect to future 

ethanol and sulfur content. The new test fuel specifications would apply to new vehicle 

certification, assembly line, and in-use testing. EPA is also proposing changes consistent 

with CARB’s LEV III emissions test fuel specifications. Key changes include:

 Moving away from “Indolene” (E0) to an E15 test fuel ;

 Lowering octane to match regular-grade gasoline (except for premiumrequired vehicles);

 Adjusting distillation temperatures, aromatics, and olefins to better match 

today’s in-use fuel and to be consistent with anticipated E15 composition; and
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 Lowering the existing sulfur specification and setting a benzene specification 

to be consistent with proposed Tier 3 gasoline sulfur requirements and recent 

MSAT2 gasoline benzene requirements.18

The proposed E15 emissions test fuel specifications are detailed in Section IV.D.1 

as well as §1065.710 of the proposed regulations. For more information on how we 

arrived at the proposed fuel parameters and ASTM test methods, refer to Chapter 3 of the 

draft Regulatory Impact Analysis (RIA).

In addition to proposing a new E15 emissions test fuel, we are also proposing for 

the first time detailed specifications for the E85 emissions test fuel used for flexible fuel 

vehicle (FFV) certification, as discussed in Section IV.D.2.19 This is intended to avoid 

uncertainty and confusion in the certification of FFVs designed to operate on ethanol 

levels up to 83 percent. Furthermore, we are proposing to allow vehicle manufacturers to 

request approval for an alternative certification fuel such as a high-octane 30 percent 

ethanol by volume (E30) blend for vehicles they might design or optimize for use on such 

a fuel. This could help manufacturers that 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 (2017 LD GHG). This in turn could help provide a 

market incentive to increase ethanol use beyond E10 by overcoming the disincentive of 

lower fuel economy associated with increasing ethanol concentrations in fuel, and 

enhance the environmental performance of ethanol as a transportation fuel by using it to 

enable more fuel efficient engines. We are seeking comment on the aspects of the test 

fuel certification that we are proposing to change as well as seeking comment on whether 

there are other aspects of today’s proposed standards that might need to be modified to 

provide an incentive for, or remove obstacles to, the development of highly efficient 

vehicles optimized for use on higher level ethanol blends.

6. Fuel Standards

Under the Tier 3 fuel program, we are proposing that gasoline and any ethanolgasoline blend contain no more than 10 ppm sulfur on an annual average basis by January

1, 2017. Similar to the Tier 2 gasoline program, the proposed Tier 3 program would 

apply to gasoline in the U.S. and the U.S. territories of Puerto Rico and the Virgin 

Islands, excluding California. The proposed program would 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., pipelines, 

terminals, marketers, ethanol industry representatives, transmix processors, additive 

manufacturers), we are proposing a Tier 3 fuel program that contains considerable 

flexibility to ease both initial and long-term implementation of the program. We are 

proposing an averaging, banking, and trading (ABT) program that would allow refiners 

 

18 72 FR 8434 (February 26, 2007).

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

and E85 test fuels. However, there are currently no detailed regulatory specifications regarding the 

composition of E85 test fuels.
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and importers to spread out their investments through an early credit program and rely on 

ongoing nationwide averaging to meet the 10-ppm sulfur standard. We are also 

proposing a three-year delay for small refiners and “small volume refineries” processing 

less than or equal to 75,000 barrels of crude oil per day. As a result of the early credit 

program, even considering the proposed ABT program and flexibilities offered to small 

refiners and small volume refineries, we anticipate considerable reductions in gasoline 

sulfur levels prior to 2017, with final refinery control to the 10-ppm average occurring by 

January 1, 2020. For more on the proposed gasoline sulfur program flexibilities, refer to 

Section V.D. 

Under today’s Tier 3 gasoline sulfur program, we are proposing to either maintain 

the current 80-ppm refinery gate and 95-ppm downstream per-gallon caps or lower them 

to 50 and 65 ppm, respectively. We also evaluated and are seeking comment on the 

potential of lowering the per-gallon caps to as low as 20 and 25 ppm. There are 

advantages and disadvantages with each of the various sulfur cap options (explained in 

more detail in Section V.A.3), but under all scenarios, the stringency of the 10-ppm 

annual average standard would result in reduced gasoline sulfur levels nationwide. A 

summary of the proposed Tier 3 sulfur standards is provided in Table I-6.

Table I-6 Proposed Tier 3 Gasoline Sulfur Standards

Proposed Tier 3 Gasoline Sulfur 

Standards

Cap Option 1 Cap Option 2

Limit Effective Limit Effective

Refinery annual average standard 10 ppm January 1, 2017a10 ppm January 1, 2017a

Refinery gate per-gallon cap 80 ppm Already 50 ppm January 1, 2020

Downstream per-gallon cap 95 ppm Already 65 ppm March 1, 2020 

a Effective January 1, 2020 for eligible small refiners and small volume refineries.

We are proposing 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.

The proposed vehicle emissions standards are fuel neutral (i.e. they are applicable 

regardless of the type of fuel that the vehicle is designed to use). The sulfur content of 

highway diesel fuel is already required to meet a 15ppm sulfur cap. Thus, no further 

action is needed to enable diesel fuel vehicles to meet the proposed emissions standards. 

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

and liquid propane gas (LPG) vehicles. We request comment on whether it is necessary

for EPA to establish sulfur standards for CNG and LPG, and whether a 15 ppm sulfur cap 

similar to that established for highway diesel fuel would be appropriate. Comment is also 

requested on whether and how to address the sulfur contribution from odorants and other 

additives used in CNG and LPG.

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

becoming increasingly important that all fuels used in FFVs, not just gasoline, meet fuel 
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quality standards. A lack of clarity regarding the standards that apply to fuels used in 

FFVs could act to impede the further expansion of ethanol blended fuels with 

concentrations greater than 15 volume percent, which is important to satisfying the 

requirements of the RFS2 program. For these reasons, we believe it is important that our 

gasoline quality standards for not only sulfur, but also benzene, RVP, detergency, and 

chemical composition (i.e., contains only carbon, hydrogen, oxygen, nitrogen, and sulfur) 

apply to any fuel used in an FFV. At the same time, it is not necessarily clear how we 

should implement such standards within the context of our existing regulations as these 

fuels tend to be produced downstream of the petroleum refinery. For this reason we are 

seeking comment on both the need to extend our gasoline standards to all gasolineethanol blends, as well as the appropriate regulatory mechanisms for doing so. 

7. Regulatory Streamlining and Technical Amendments

We are proposing and requesting comment in this action on a number of items to 

help streamline the in-use fuels regulations at 40 CFR part 80. The majority of items 

involve clarifying vague or inconsistent language, removal or updating of outdated 

provisions, and decrease 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 would reduce burden on industry and allow us to achieve the standards 

and resulting environmental benefits 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 proposing for the in-use fuels 

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

In addition, there are a number of items that we believe need further consideration and 

discussion on which we are seeking comment. 

The proposal also includes a variety of technical amendments to certificationrelated requirements for engine and vehicle emission standards. We are proposing to 

revise the fuel economy labeling requirements to correspond to the new Tier 3 standards. 

We are also proposing to remove obsolete regulatory text and make 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 Would the Impacts of the Proposed Standards Be?

The proposed Tier 3 vehicle and fuel standards together would reduce 

dramatically emissions of NOX, VOC, PM2.5, and air toxics. The gasoline sulfur 

standards, which would take effect in 2017, would provide large immediate reductions in 

emissions from existing gasoline vehicles and engines. NOX emissions would be reduced 

by about 284,000 tons, or about 8 percent of emissions from on-highway vehicles, in 

2017 alone. The emission reductions would increase over time as newer vehicles become 

a larger percentage of the fleet. In 2030, when 80 percent of the light-duty fleet (and 90 
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percent of the vehicle miles travelled) consists of Tier 3 vehicles, we expect the NOX and 

VOC emissions to be reduced by about 525,000 tons and 226,000 tons, respectively, or 

one quarter of emissions from on-highway vehicles compared to their 2030 levels without 

the Tier 3 program. Emissions of CO would decrease by almost 6 million tons, or 30 

percent of emissions from on-highway vehicles. Emissions of many air toxics would also 

be reduced, including benzene, 1,3-butadiene, acetaldehyde, formaldehyde, acrolein and 

ethanol, with reductions ranging from 10 to nearly 40 percent of national emissions from 

on-highway vehicles. We expect these reductions to continue beyond 2030 as only 80% 

of the vehicles would have turned over to Tier 3 standards by 2030 

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

proposed Tier 3 standards are projected to lead to significant decreases in ambient 

concentrations of ozone, PM2.5 and air toxics by 2030, and would immediately reduce 

ozone in 2017 when the proposed sulfur controls take effect. Specifically, the proposed 

Tier 3 standards would significantly decrease ozone concentrations across the country, 

with a population-weighted annual average decrease of 0.47 ppb in 2017 and 1.55 ppb in 

2030 from projected population-weighted average levels of 71.3 ppb in 2017 and 66.7 

ppb in 2030. The magnitude of reductions is significant enough to bring ozone levels in 

five counties from above the standard to below the standard, even without any additional 

controls. Few other national strategies exist that would deliver the reductions needed for 

states to meet the current ozone standards. The proposed Tier 3 standards would decrease 

annual ambient PM2.5 concentrations across the country in nonattainment and highlypopulated urban areas, with a population-weighted annual average decrease of 0.06

μg/m3by 2030 from projected population-weighted average levels of 9.3 ug/m3 in 2017 

and 9.5 ug/m3 in 2030. The proposed Tier 3 standards are not projected to bring any 

counties into attainment with any annual or 24-hour PM2.5 NAAQS standard. Decreases 

in ambient concentrations of air toxics are also projected with the proposed standards, 

including notable nationwide reductions in benzene concentrations. Additional 

information on the emission and air quality impacts of the proposed 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 proposed Tier 3 standards 

would 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 annual 

emission reductions of the Tier 3 standards would annually prevent between 670 and 

1,700 PM-related premature deaths, between 160 and 710 ozone-related premature 

deaths, 81,000 work days lost, and approximately 1.4 million minor restricted-activity 

days. The estimated annual monetized health benefits of the proposed Tier 3 standards in 

2030 (2010$) would be between $8.0 and $23 billion, assuming a 3-percent discount rate 

(or between $7.4 billion and $21 billion assuming a 7-percent discount rate). 20 The 

 

20 These benefits estimates have been adjusted to remove benefits of the Tier 3 program in California. The 

Tier 3 proposal’s analysis assumed emissions reductions and resulting benefits would occur nationwide. 
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proposed fuel standards are projected to cost on average less than one cent per gallon of 

gasoline, and the proposed light-duty vehicle standards would have an average cost that 

increases in proportion to the increase in stringency from $50 per vehicle in 2017 to $134 

per vehicle when the standards are fully phased in 2025. The annual cost of the overall 

program in 2030 would be approximately $3.4 billion.21 The 2030 monetized benefits 

outweigh the costs by factors between 2 and 7. 

The benefits in Table I-7 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 

proposed standards. See Sections VII and VIII for detailed descriptions of the costs and 

benefits of this proposal. 

Table I-7 Summary of Annual Benefts and Costs Associated with the Proposed Tier 

3 Program (Billions, 2010$)a

Description 2030

Vehicle Program Costs

Fuels Program Costs

Total Estimated Costsb

$2.1

$1.3

$3.4

Total Estimated Health Benefitsc,d,e,f,g

 3 percent discount rate

 7 percent discount rate

$8.0 - $23

$7.4 - $21

Annual Net Benefits (Total Benefits – Total Costs)

 3 percent discount rate

 7 percent discount rate

$4.6 - $20

$4.0 - $18

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). The program costs include the costs associated with the 

Tier 3 vehicle and fuel standards in all states except California.

c The benefits presented in this table have been adjusted to remove benefits of the Tier 3 program in 

California.

d Total includes ozone and PM2.5 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 (Pope et al., 2002) 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 (Laden et al., 2006) study for the high estimate.

 

California was recently granted a Clean Air Act waiver of preemption for the LEV III vehicle program, and 

some other states have adopted it. The Tier 3 final rule analysis will account for those emission reductions 

that will occur even in the absence of Tier 3 vehicle standards, for all states that have adopted LEV III. See 

Section VIII of the preamble for more information on the benefits associated with the Tier 3 program. 

21 Costs include estimates for the proposed Tier 3 standards in all states except California.
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e 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. 

f 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 2006 

PM National Ambient Air Quality Standards (September, 2006). 

g 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 Making This Proposal? 

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 

cardiovascular problems and other adverse health impacts leading to increased 

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

mortality. Over 158 million people currently live in areas designated nonattainment for 

one or more of the current NAAQS.22 

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.23 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.24

 More than 50 million people 

 

22 Data come from Summary Nonattainment Area Population Exposure Report, current as of December 14, 

2012 at: http://www.epa.gov/oar/oaqps/greenbk/popexp.html and contained in Docket EPA-HQ-OAR2011-0135.

23 U.S. EPA. (2011) Summary of Results for the 2005 National-Scale Assessment. 

www.epa.gov/ttn/atw/nata2005/05pdf/sum_results.pdf.

24 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
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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 nearly 90 percent of daily

trips occurring by personal vehicle.25,26,27 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 

maintain the NAAQS for ten years (and eight years later, a similar demonstration is 

required for another ten-year period). The proposed Tier 3 standards would be a critical 

part of areas’ strategies to attain and maintain the standards. Maintaining the standards 

has been challenging in the past, particularly for areas where high population growth 

rates lead to significant annual increases in vehicle trips and vehicle miles traveled. Our 

air quality modeling for this proposal, which is described in more detail in Section III.C, 

projects that in 2017 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 would benefit from the proposed Tier 3 standards as they work to ensure 

long-term maintenance of the NAAQS. 

Section III provides more detail on how this proposal would reduce motor vehicle 

emissions and ambient levels of pollution. The proposed rule would meaningfully reduce 

ozone concentrations as early as 2017 (the first year of the program), and even more 

significantly in 2030. The 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 would reduce ambient 

PM2.5 concentrations. 

Without this proposal 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 proposed Tier 3 

standards. Furthermore, states outside California 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 proposed Tier 3 emissions standards 

throughout their useful life. 

 

25 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

26 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

27 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/
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The reductions in ambient ozone and PM2.5 that would result from the proposed 

Tier 3 standards would provide significant health benefits. By 2030, the standards would 

annually prevent between 670 and 1,700 PM-related premature deaths, between 160 and 

710 ozone-related premature deaths, 81,000 work days lost, and approximately 1.4 

million minor restricted-activity days (see Section VIII for more details). This proposal 

would also reduce air toxics; for example, we project that in 2030, the proposal would 

decrease ambient benzene concentrations by 10-25 percent in some urban areas. 

Furthermore, the proposed Tier 3 standards would reduce traffic-associated pollution near 

major roads. EPA is proposing 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 2017.28 The Tier 3 standards in this proposal, which 

address non-GHGs, would 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 could design a single 

vehicle for nationwide sales. This reduces the cost of compliance for auto manufacturers.

This Tier 3 proposal 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.29 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 proposing to set 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 also 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 vehicles30

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 

 

28 77 FR 62623 (October 15, 2012).

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

30 LDTs that have gross vehicle weight ratings above 6000 lbs are considered ‘‘heavy-duty vehicles’’ under 

the CAA. See section 202(b)(3)(C). For regulatory purposes, we refer to those LDTs at or below 8500 lbs 

GVWR as ‘‘heavy light-duty trucks’’ made up of LDT3s and LDT4s.
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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 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 proposing to adopt 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 

proposing 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 levels 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. 

Approximately 159 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.31 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.32 In addition, populations who live, work, or attend school 

 

31 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.

32 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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near major roads experience elevated exposure concentrations to a wide range of air 

pollutants.33

EPA has already adopted many emission control programs that are expected to 

reduce ambient pollution levels. 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 completed 

for this proposed rule predicts that without additional controls there will continue to be a 

need for reductions in ozone, PM2.5 and air toxics concentrations in the future. Section 

III.C of this preamble presents the air quality modeling results for this proposed rule. 

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

The health and welfare effects of ozone are well documented and are assessed in 

EPA’s 2006 Air Quality Criteria Document and 2007 Staff Paper.34,35 People who are 

more susceptible to effects associated with exposure to ozone can include children, the 

elderly, and individuals with respiratory disease such as asthma. Those with greater 

exposures to ozone, for instance due to time spent outdoors (e.g., children and outdoor 

 

33

 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] 

34 U.S. EPA. (2006). Air Quality Criteria for Ozone and Related Photochemical Oxidants (Final). 

EPA/600/R-05/004aF-cF. Washington, DC: U.S. EPA. 

35 U.S. EPA. (2007). Review of the National Ambient Air Quality Standards for Ozone: Policy Assessment 

of Scientific and Technical Information, OAQPS Staff Paper. EPA-452/R-07-003. Washington, DC, U.S. 

EPA.
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workers), are of particular concern. Ozone can irritate the respiratory system, causing 

coughing, throat irritation, and breathing discomfort. Ozone can reduce lung function 

and cause pulmonary inflammation in healthy individuals. Ozone can also aggravate 

asthma, leading to more asthma attacks that require medical attention and/or the use of 

additional medication. Thus, ambient ozone may cause both healthy and asthmatic 

individuals to limit their outdoor activities. In addition, there is suggestive evidence of a 

contribution of ozone to cardiovascular-related morbidity and highly suggestive evidence 

that short-term ozone exposure directly or indirectly contributes to non-accidental and 

cardiopulmonary-related mortality, but additional research is needed to clarify the 

underlying mechanisms causing these effects. In a report on the estimation of ozonerelated premature mortality published by the National Research Council (NRC), 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.36 Animal toxicological 

evidence indicates that with repeated exposure, ozone can inflame and damage the lining 

of the lungs, which may lead to permanent changes in lung tissue and irreversible 

reductions in lung function. The respiratory effects observed in controlled human 

exposure studies and animal studies are coherent with the evidence from epidemiologic 

studies supporting a causal relationship between acute ambient ozone exposures and 

increased respiratory-related emergency room visits and hospitalizations in the warm 

season. In addition, there is suggestive evidence of a contribution of ozone to 

cardiovascular-related morbidity and non-accidental and cardiopulmonary mortality.

c. Current and Projected Ozone Levels

Concentrations that exceed the level of the ozone NAAQS occur in many parts of 

the country, including many major population centers. In addition, our modeling without 

the proposed Tier 3 controls projects that in the future we will continue to have many 

areas that will have ambient ozone concentrations above the level of the NAAQS (see 

Section III.C.1). States will need to meet the standard in the 2015-2032 timeframe. The 

emission reductions and significant ambient ozone improvements from this proposed 

rule, which would take effect starting in 2017, would 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.37,38 As of December 

14, 2012, there were 41 ozone nonattainment areas for the 1997 ozone NAAQS 

composed of 221 full or partial counties with a total population of over 118 million. 

 

36 National Research Council. (2008). Estimating Mortality Risk Reduction and Economic Benefits from 

Controlling Ozone Air Pollution. The National Academies Press: Washington, D.C. 

37 69 FR 23858 (April 30, 2004).

38 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.
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Nonattainment designations for the 2008 ozone standard were finalized on April 30, 2012 

and May 31, 2012.39 These designations include 46 areas, composed of 227 full or partial 

counties, with a population of over 123 million. As of December 14, 2012, over 138

million people are living in ozone nonattainment areas.40 

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 are required to attain 

the 1997 8-hour ozone NAAQS in the 2007 to 2013 time frame and then to maintain it 

thereafter.41 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 working to complete the current review of the 

ozone NAAQS by mid-2014. If EPA revises the ozone standards in 2014 pursuant to that 

review, the attainment dates associated with areas designated nonattainment for that 

NAAQS would likely be in the 2019 to 2036 timeframe, 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 

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 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.

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 um in diameter and a grain of salt is about 100 μm). Atmospheric 

 

39 77FR 30088 (May 21, 2012).

40 The 138 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.

41 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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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). 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 and referring to total particle 

mass under 2.5 and between 2.5 and 10 micrometers, respectively. The EPA currently has 

standards that measure PM2.5 and PM10.

42

 

Particles span many sizes and shapes and 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 pollution also varies by time of year and 

location and 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), nitrogen oxides (NOX), 

and volatile organic compounds (VOC)) in the atmosphere. The chemical and physical 

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 series of adverse health 

effects. These health effects are discussed in detail in EPA’s Integrated Science 

Assessment (ISA) for Particulate Matter.43 Further discussion of health effects associated 

with PM can also be found in the draft RIA. The ISA summarizes health effects evidence 

associated with both short-term and long-term exposures to PM2.5, PM10-2.5, and ultrafine 

particles.

The ISA concludes that health effects associated with short-term exposures (hours 

to days) to ambient PM2.5 include mortality, cardiovascular effects, such as altered 

vasomotor function and myocardial ischemia, and hospital admissions and emergency

department visits for ischemic heart disease and congestive heart failure, and respiratory

 

42 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.

43 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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effects, such as exacerbation of asthma symptoms in children and hospital admissions 

and emergency department visits for chronic obstructive pulmonary disease and 

respiratory infections.44 The ISA notes that long-term exposure (months to years) to 

PM2.5 is associated with the development/progression of cardiovascular disease, 

premature mortality, and respiratory effects, including reduced lung function growth in 

children, increased respiratory symptoms, and asthma development.45 The ISA 

concludes that the currently available scientific evidence from epidemiologic, controlled 

human exposure, and toxicological studies supports a causal association between shortand long-term exposures to PM2.5 and cardiovascular effects and premature mortality. 

Furthermore, the ISA concludes that the collective evidence supports likely causal 

associations between short- and long-term PM2.5 exposures and respiratory effects. The 

ISA also concludes that the scientific evidence is suggestive of a causal association for 

reproductive and developmental effects including respiratory-related infant mortality, and 

cancer, mutagenicity, and genotoxicity and long-term exposure to PM2.5.

46

For PM10-2.5, the ISA concludes that the current evidence is suggestive of a causal 

relationship between short-term exposures and premature mortality, cardiovascular 

effects, and respiratory effects. Data are inadequate to draw conclusions regarding the 

health effects associated with long-term exposure to PM10-2.5.

47

For ultrafine particles, the ISA concludes that there is suggestive evidence of a 

causal relationship between short-term exposures and cardiovascular effects, such as 

changes in heart rhythm and blood vessel function. It also concludes that there is 

suggestive evidence of association between short-term exposure to ultrafine particles and 

respiratory effects. Data are inadequate to draw conclusions regarding the health effects 

associated with long-term exposure to ultrafine particles.48

c. Current and Projected PM2.5 Levels

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 proposed 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 24-hour standard in the 2015-2019 timeframe and the annual standard in 

the 2021-2025 timeframe. The emission reductions and improvements in ambient PM2.5

 

44 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 2.3.1.1.

45 U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. 

Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F. page 2-12, Sections 7.3.1.1 and 

7.3.2.1.

46 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 2.3.2.

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. Section 2.3.4 and Table 2-6.

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. Section 2.3.5 and Table 2-6.
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from this proposed rule, which would take effect starting in 2017, would be helpful to 

states as they work to maintain the PM2.5 NAAQS.

There are two NAAQS for PM2.5: an annual standard (12 micrograms per cubic 

meter (μg/m3)) and a 24-hour standard (35 μg/m3). The most recent revisions to these 

standards were in 1997, 2006 and in December 2012. The December 2012 rule revised 

the level of the annual PM2.5 standard from 15 μg/m

3

to 12 μg/m3.

49

In 2005 EPA designated nonattainment areas for the 1997 PM2.5 NAAQS.50 As of 

December 14, 2012, over 91 million people lived in the 35 areas that are designated as 

nonattainment for the 1997 PM2.5 NAAQS. These PM2.5 nonattainment areas are 

comprised of 191 full or partial counties. On October 8, 2009, the EPA issued final 

nonattainment area designations for the 2006 24-hour PM2.5 NAAQS.51 These 

designations include 32 areas composed of 121 full or partial counties with a population 

of over 70 million. In total, there are 50 PM2.5 nonattainment areas with a population of 

over 105 million people.52 

States with PM2.5 nonattainment areas will be required to take action to bring 

those areas into attainment in the future. Most 1997 PM2.5 nonattainment areas are 

required to attain the 1997 PM2.5 NAAQS in the 2010 to 2015 time frame and then 

required to maintain the 1997 PM2.5 NAAQS thereafter.53 The 2006 24-hour PM2.5

nonattainment areas will be required to attain the 2006 24-hour PM2.5 NAAQS in the 

2014 to 2019 time frame and then be required to maintain the 2006 24-hour PM2.5

NAAQS thereafter.54 The 2012 PM2.5 nonattainment areas will likely be required to 

attain the 2012 PM2.5 NAAQS in the 2020 to 2025 time frame, depending on the severity 

of an area’s fine particle pollution problems and the availability of pollution controls. 

The standards proposed here begin taking effect in 2017. 

EPA has already adopted many mobile source emission control programs that are 

expected to reduce ambient PM levels. 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 

 

49 U.S. EPA (2012). National Ambient Air Quality Standards for Particulate Matter. 

http://www.epa.gov/PM/2012/finalrule.pdf

50 70 FR 19844 (April 14, 2005).

51 74 FR 58688 (November 13, 2009).

52

 Data come from Summary Nonattainment Area Population Exposure Report, current as of December 14, 

2012 at: http://www.epa.gov/oar/oaqps/greenbk/popexp.html and contained in Docket EPA-HQ-OAR2011-0135. 

53 U.S. EPA. (2007). PM2.5 National Ambient Air Quality Standard Implementation Rule (Final). 

Washington, DC: U.S. EPA. 72 FR 20586, April 25, 2007. 

54 U.S. EPA. (2011). PM Standards Revision – 2006: Timeline. Available at 

http://www.epa.gov/PM/naaqsrev2006.html#timeline. Accessed December 31, 2011. 
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practicable and may relieve areas with already stringent local regulations from some of 

the burden associated with adopting additional local controls.

3. Nitrogen Oxides and Sulfur Oxides

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

Information on the health effects of NO2 can be found in the EPA Integrated 

Science Assessment (ISA) for Nitrogen Oxides.55 The EPA has 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 ISA concludes that the strongest evidence for 

such a relationship comes from epidemiologic studies of respiratory effects including 

symptoms, emergency department visits, and hospital admissions. Based on both shortand long-term studies, the ISA concludes that associations of NO2 with respiratory health 

effects are stronger among a number of groups; these include individuals with preexisting 

pulmonary conditions (e.g., asthma or COPD), children and older adults. The ISA also 

draws two broad conclusions regarding airway responsiveness following NO2 exposure. 

First, the ISA concludes that NO2 exposure may enhance the sensitivity to allergeninduced decrements in lung function and increase the allergen-induced airway

inflammatory response following 30-minute exposures of asthmatics to NO2

concentrations as low as 0.26 ppm. 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 asthmatic subjects. Small but significant increases 

in non-specific airway hyperresponsiveness were reported following 1-hour exposures of 

asthmatics to 0.1 ppm NO2. Enhanced airway responsiveness could have important 

clinical implications for asthmatics since transient increases in airway responsiveness 

following NO2 exposure have the potential to increase symptoms and worsen asthma 

 

55 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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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. 

Although the weight of evidence supporting a causal relationship is somewhat 

less certain than that associated with respiratory morbidity, NO2 has also been linked to 

other health endpoints. These include all-cause (nonaccidental) mortality, hospital 

admissions or emergency department visits for cardiovascular disease, and decrements in 

lung function growth associated with chronic exposure.

c. Health Effects of SO2

Information on the health effects of SO2 can be found in the EPA Integrated 

Science Assessment for Sulfur Oxides.56 SO2 has long been known to cause adverse 

respiratory health effects, particularly among individuals with asthma. Other potentially 

sensitive groups include 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 has 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 has concluded that the overall evidence is suggestive of a causal 

relationship between short-term exposure to SO2 and mortality.

d. Current Levels of NO2

Between 2003 and 2005, national mean concentrations of NO2 were about 15 

parts per billion (ppb) for averaging periods ranging from a day to a year.57 There are 

two NAAQS for NO2: an annual standard (53 ppb) and a 1-hour standard (100 ppb). The 

primary NAAQS for NO2 was revised in January 2010. EPA completed area 

designations in January 2012 and there are currently no nonattainment areas. The 

designations were based on the existing community-wide monitoring network. Once the 

expanded network of NO2 monitors is fully deployed and three years of air quality data 

have been collected, EPA intends to redesignate areas, as appropriate, based on the air 

quality data from the new monitoring network.58,59

 

56 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.

57 U.S. EPA. (2010). Final Regulatory Impact Analysis (RIA) for the NO2 National Ambient Air Quality 

Standards (NAAQS). http://www.epa.gov/ttn/ecas/regdata/RIAs/FinalNO2RIAfulldocument.pdf

58 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

59 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
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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 EPA Integrated 

Science Assessment (ISA) for Carbon Monoxide.60 The ISA concludes that ambient 

concentrations of CO are associated with a number of adverse health effects.61 This 

section provides a summary of the health effects associated with exposure to ambient 

concentrations of CO.62 

Human clinical 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 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 inconsistent neural and behavioral effects 

following low-level CO exposures. The 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 epidemiologic and animal toxicological studies cited in the ISA have 

evaluated associations between CO exposure and birth outcomes such as preterm birth or 

cardiac birth defects. The epidemiologic studies provide limited evidence of a CO-

 

60 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. 

61 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. 

62 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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induced effect on preterm births and birth defects, with weak evidence for a decrease in 

birth weight. Animal toxicological studies have found associations between perinatal CO 

exposure and decrements in birth weight, as well as other developmental outcomes. The 

ISA concludes these studies are suggestive of a causal relationship between long-term 

exposures to CO and developmental effects and birth outcomes.

Epidemiologic studies provide evidence of effects on respiratory morbidity such 

as changes in pulmonary function, respiratory symptoms, and hospital admissions 

associated with ambient CO concentrations. 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 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 ISA concludes that the evidence is suggestive of a causal relationship between shortterm CO exposure and respiratory morbidity, and inadequate to conclude that a causal 

relationship exists between long-term exposure and respiratory morbidity. 

Finally, the ISA concludes that the epidemiologic evidence is suggestive of a 

causal relationship between short-term exposures to 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 ISA also 

concludes that there is not likely to be a causal relationship between relevant long-term 

exposures to CO and mortality.

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.”63 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.64 

a. Health Effects of Air Toxics

 

63 U.S. EPA. (2011) Summary of Results for the 2005 National-Scale Assessment. 

www.epa.gov/ttn/atw/nata2005/05pdf/sum_results.pdf. 

64 U.S. EPA (2011) 2005 National-Scale Air Toxics Assessment. http://www.epa.gov/ttn/atw/nata2005. 
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i. Benzene

The EPA’s 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.65,66,67 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

-6

to 7.8 x 10-6as the unit risk 

estimate (URE) for benzene.68,69 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.70,71 

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.72,73 The most sensitive noncancer effect observed in humans, based on current 

data, is the depression of the absolute lymphocyte count in blood.74,75 EPA’s inhalation 

reference concentration (RfC) for benzene is 30 μg/m3. The RfC is based on suppressed 

 

65 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. 

66 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. 

67 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. 

68 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.

69 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. 

70 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.

71 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. 

72 Aksoy, M. (1989). Hematotoxicity and carcinogenicity of benzene. Environ. Health Perspect. 82: 193-

197. 

73 Goldstein, B.D. (1988). Benzene toxicity. Occupational medicine. State of the Art Reviews. 3: 541-

554.

74 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. 

75 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. 
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absolute lymphocyte counts seen in humans under occupational exposure conditions. In 

addition, recent work, including studies sponsored by the Health Effects Institute (HEI), 

provides evidence that biochemical responses are occurring at lower levels of benzene 

exposure than previously known.76,77,78,79 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.80,81

ii. Formaldehyde 

In 1991, EPA concluded that formaldehyde is a carcinogen based on nasal tumors 

in animal bioassays.82 An Inhalation Unit Risk for cancer and a Reference Dose for oral 

noncancer effects were developed by the Agency and posted on the Integrated Risk 

Information System (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.83,84,85

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 

 

76 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.

77 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. 

78 Lan, Qing, Zhang, L., Li, G., Vermeulen, R., et al. (2004). Hematotoxically in Workers Exposed to Low

Levels of Benzene. Science 306: 1774-1776.

79 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. 

80 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.

81 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.

82 EPA. Integrated Risk Information System. Formaldehyde (CASRN 50-00-0) 

http://www.epa.gov/iris/subst/0419/htm

83 National Toxicology Program, U.S. Department of Health and Human Services (HHS), 12th Report on 

Carcinogens, June 10, 2011

84 IARC Monographs on the Evaluation of Carcinogenic Risks to Humans Volume 88 (2006): 

Formaldehyde, 2-Butoxyethanol and 1-tert-Butoxypropan-2-ol

85 IARC Mongraphs on the Evaluation of Carcinogenic Risks to Humans Volume 100F (2012): 

Formaldehyde
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workers exposed to formaldehyde.86,87,88 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.89 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.90 Finally, a study of embalmers reported formaldehyde exposures 

to be associated with an increased risk of myeloid leukemia but not brain cancer.91

Health effects of formaldehyde in addition to cancer were reviewed by the 

Agency for Toxics Substances and Disease Registry in 199992 and supplemented in 

2010,93 and by the World Health Organization.94 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 

(NRC) and public comment in June 2010.95 The draft assessment reviewed more recent 

research from animal and human studies on cancer and other health effects. The NRC 

 

86 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. 

87 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. 

88 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. 

89 Pinkerton, L. E. 2004. Mortality among a cohort of garment workers exposed to formaldehyde: an 

update. Occup. Environ. Med. 61: 193-200.

90 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.

91 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.

92 ATSDR. 1999. Toxicological Profile for Formaldehyde, U.S. Department of Health and Human Services 

(HHS), July 1999.

93 ATSDR. 2010. Addendum to theToxicological Profile for Formaldehyde. U.S. Department of Health and 

Human Services (HHS), October 2010.

94 IPCS. 2002. Concise International Chemical Assessment Document 40. Formaldehyde. World Health 

Organization.

95 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
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released their review report in April 2011.96 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.97 The URE in IRIS for acetaldehyde is 2.2 × 10-6per μg/m3.

98

 

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.99,100 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.101 In short-term (4 week) rat studies, 

degeneration of olfactory epithelium was observed at various concentration levels of 

acetaldehyde exposure.102,103 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 

bronchoconstriction upon acetaldehyde inhalation.104 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 

 

96 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

97 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. 

98 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. 

99 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.

100 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.

101 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. 

102 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. 

103 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. 

104 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. 
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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.

105

 The IARC determined in 1995 that acrolein 

was not classifiable as to its carcinogenicity in humans.106 

Lesions to the lungs and upper respiratory tract of rats, rabbits, and hamsters have 

been observed after subchronic exposure to acrolein.107 The Agency has developed an 

RfC for acrolein of 0.02 μg/m3 and an RfD of 0.5 μg/kg-day.

108

 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.109 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.110 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 

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 mice111) 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 

 

105 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. 

106 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. 

107 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. 

108 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. 

109 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. 

110 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. 

111 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. 
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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.

112

v. 1,3-Butadiene

EPA has characterized 1,3-butadiene as carcinogenic to humans by

inhalation.113,114 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.115,116,117 

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 

URE for 1,3-butadiene is 3 × 10-5per μg/m3.

118 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.119 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

 

112 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 

113 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. 

114 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. 

115 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. 

116 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. 

117 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.

118 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. 

119 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.
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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.131,132 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.133 In 1997 EPA classified seven PAHs (benzo[a]pyrene, 

benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, 

dibenz[a,h]anthracene, and indeno[1,2,3-cd]pyrene) as Group B2, probable human 

carcinogens.134 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).135,136 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.

 

131 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. 

132 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. 

133 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.

134 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. 

135 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. 

136 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. 
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viii. PAN

PAN (peroxy acetyl nitrate) has not been evaluated by EPA’s IRIS program. 

Information regarding the potential carcinogenicity of PAN is limited. As noted in the 

EPA air quality criteria document for ozone and related photochemical oxidants, 

cytogenetic studies indicate that PAN is not a potent mutagen, clastogen (a compound 

that can cause breaks in chromosomes), or DNA-damaging agent in mammalian cells 

either in vivo or in vitro. Some studies suggest that PAN may be a weak bacterial 

mutagen at concentrations much higher than exist in present urban atmospheres.137

Effects of ground-level smog causing intense eye irritation have been attributed to 

photochemical oxidants, including PAN.138 Animal toxicological information on the 

inhalation effects of the non-ozone oxidants has been limited to a few studies on PAN. 

Acute exposure to levels of PAN can cause changes in lung morphology, behavioral 

modifications, weight loss, and susceptibility to pulmonary infections. Human exposure 

studies indicate minor pulmonary function effects at high PAN concentrations, but large 

inter-individual variability precludes definitive conclusions.139

ix. 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.140 Chronic (long term) exposure 

of workers and rodents to naphthalene has been reported to cause cataracts and retinal 

damage.141 EPA released an external review draft of a reassessment of the inhalation 

 

137 U.S. EPA. (2006). Air quality criteria for ozone and related photochemical oxidants (Ozone CD). 

Research Triangle Park, NC: National Center for Environmental Assessment; report no. EPA/600/R05/004aF-cF.3v. page 5-78 Available at http://cfpub.epa.gov/ncea/. 

138 U.S. EPA (2005). Air Quality Criteria for Ozone and Related Photochemical Oxidants (Final). U.S. 

Environmental Protection Agency, Washington, D.C., EPA 600/R-05/004aF-cF, 2006. page 5-63. This 

document is available in Docket EPA-HQ-OAR-2005-0161. This document may be accessed 

electronically at: http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_cr_cd.html 

139 U.S. EPA (2005).Air Quality Criteria for Ozone and Related Photochemical Oxidants (Final). U.S. 

Environmental Protection Agency, Washington, D.C., EPA 600/R-05/004aF-cF, 2006. page 5-78. This 

document is available in Docket EPA-HQ-OAR-2005-0161. This document may be accessed 

electronically at: http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_cr_cd.html 

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 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.
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carcinogenicity of naphthalene based on a number of recent animal carcinogenicity

studies.142 The draft reassessment completed external peer review.143 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 

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.144 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.145 

Naphthalene also causes a number of chronic non-cancer effects in animals, 

including abnormal cell changes and growth in respiratory and nasal tissues.146 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.

147

 The ATSDR MRL

for acute exposure to naphthalene is 0.6 mg/kg/day.

x. Other Air Toxics

In addition to the compounds described above, other compounds in gaseous 

hydrocarbon and PM emissions from light-duty vehicles would be affected by this 

proposal. Mobile source air toxic compounds that would 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.148

 

142 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. 

143 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. 

144 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.

145 International Agency for Research on Cancer (IARC). (2002). Monographs on the Evaluation of the 

Carcinogenic Risk of Chemicals for Humans. Vol. 82. Lyon, France. 

146 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 

147 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. 

148 U.S. EPA Integrated Risk Information System (IRIS) database is available at: www.epa.gov/iris 
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b. Current Levels of Air Toxics 

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.149 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.150 According to the National Air Toxic 

Assessment (NATA) for 2005,151 mobile 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.152 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.

 

149 U.S. Environmental Protection Agency (2007). Control of Hazardous Air Pollutants from Mobile 

Sources; Final Rule. 72 FR 8434, February 26, 2007.

150 U. S. Environmental Protection Agency (2007). Control of Hazardous Air Pollutants from Mobile 

Sources; Final Rule. 72 FR 8434, February 26, 2007. 

151 U. S. EPA. (2011). 2005 National-Scale Air Toxics Assessment. http://www.epa.gov/ttn/atw/nata2005/. 

152 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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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 

found higher concentrations of many carbonyls downwind of roadways.153,154 These 

findings suggest a substantial roadway source of these carbonyls.

In the past 15 years, many studies have been published with results showing 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.155 In addition, numerous studies have found adverse health effects associated with 

spending time in traffic, such as commuting or walking along high-traffic roadways. 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.156 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 

pulmonary disease (COPD), nonasthmatic respiratory allergy, and cancer in adults and 

children. Other literature reviews have been published with conclusions similar to the 

 

153 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.

154 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

155 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. 

156 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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HEI panel’s.157,158,159 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).160,161,162,163

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 increase systemic 

inflammation, affecting organ systems, including blood vessels and lungs.164,165,166,167 

Long-term exposures in near-road environments have been associated with inflammationassociated conditions, such as atherosclerosis and asthma.168,169,170

 

Several studies suggest that some factors may increase susceptibility to the effects 

of traffic-associated air pollution. Several studies have found stronger respiratory

 

157 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.

158 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.

159 Raaschou-Nielsen, O.; Reynolds, P. (2006). Air pollution and childhood cancer: a review of the 

epidemiological literature. Int J Cancer 118: 2920-9.

160 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.

161 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]

162 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.

163 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.

164 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

165 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

166 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

167 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]

168 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

169 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

170 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.
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associations in children experiencing chronic social stress, such as in violent 

neighborhoods or in homes with high family stress.171,172,173 

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. As 

discussed in Section III, 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.

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

Elevated ozone levels contribute to environmental effects, with impacts to plants 

and ecosystems being of most concern. Ozone can produce both acute and chronic injury

in sensitive species depending on the concentration level and the duration of the 

exposure. Ozone effects also tend to accumulate over the growing season of the plant, so 

that even low concentrations experienced for a longer duration have the potential to 

create chronic stress on vegetation. Ozone damage to plants includes visible injury to 

leaves and impaired photosynthesis, both of which can lead to reduced plant growth and 

reproduction, resulting in reduced crop yields, forestry production, and use of sensitive 

ornamentals in landscaping. In addition, the impairment of photosynthesis, the process 

by which the plant makes carbohydrates (its source of energy and food), can lead to a 

subsequent reduction in root growth and carbohydrate storage below ground, resulting in 

other, more subtle plant and ecosystems impacts. 

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 forest and other natural vegetation can potentially lead to 

species shifts and loss from the affected ecosystems, resulting in a loss or reduction in 

 

171 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) 

172 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.

173 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.
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associated ecosystem goods and services. Lastly, 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. The final 2006 Ozone Air Quality Criteria Document presents more 

detailed information on ozone effects on vegetation and ecosystems.

b. Visibility

Visibility can be defined as the degree to which the atmosphere is transparent to 

visible light.174 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.175

EPA is pursuing a two-part strategy to address visibility impairment. First, EPA 

developed the regional haze program which was put in place in July 1999 to protect the 

visibility in Mandatory Class I Federal areas.176 There are 156 national parks, forests and 

wilderness areas categorized as Mandatory Class I Federal areas.177 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. Second, EPA has 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, 

 

174 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/

175 U.S. EPA. (2009). Integrated Science Assessment for Particulate Matter (Final Report). U.S. 

Environmental Protection Agency, Washington, DC, EPA/600/R-08/139F. 

176 64 FR 35714 (July 1, 1999). 

177 62 FR 38680-38681 (July 18, 1997).
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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.178

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.179,180,181,182,183 

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

 

178 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. 

179 U.S. EPA. (2004). National Coastal Condition Report II. Office of Research and Development/ Office of 

Water. EPA-620/R-03/002. 

180 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. 

181 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. 

182 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. 

183 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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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.

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). 

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 17 years. 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, 
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while total nitrogen deposition decreased by 25 percent over the same time frame.184 

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.185

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.186 In laboratory experiments, a wide range of tolerance 

to VOCs has been observed.187 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 

toluene on herbaceous plants, significant effects on seed production, leaf water content 

and photosynthetic efficiency were reported for some plant species.188

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.189,190, 191 

 

184 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. 

185 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. 

186 U.S. EPA. (1991). Effects of organic chemicals in the atmosphere on terrestrial plants. EPA/600/3-

91/001. 

187 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. 

188 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. 

189 Viskari E-L. (2000). Epicuticular wax of Norway spruce needles as indicator of traffic pollutant 

deposition. Water, Air, and Soil Pollut. 121:327-337. 

190 Ugrekhelidze D, F Korte, G Kvesitadze. (1997). Uptake and transformation of benzene and toluene by 

plant leaves. Ecotox. Environ. Safety 37:24-29. 

191 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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III. How Would This Proposal Reduce Emissions and Air

Pollution?

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

The vehicle and fuel standards that EPA is proposing would significantly reduce 

the tailpipe and evaporative emissions of light- and heavy-duty vehicles in several ways, 

as described in this section. In addition, the proposed gasoline sulfur standard would 

reduce emissions of SO2 from existing gasoline-powered vehicles and equipment. As 

described in Section II, all of these emission reductions would 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 proposing to implement closely-coordinated 

requirements for both automakers and refiners in the same rulemaking action. The 

proposed 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 

proposed rule, we have been able to integrate the provisions into a single, coordinated 

program. 

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

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. 

a. Tailpipe (Exhaust) Emissions

Which pollutants are 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 (primarily as elemental carbon, usually called soot) and 
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also indirectly as semi-volatile 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 the gasoline, which, like exhaust hydrocarbons, contribute to 

concentrations of VOCs in the atmosphere. 

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 hose material, 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 would be 

improved under this proposed rule) consist of a canister filled with activated charcoal and 

connected by hoses to the fuel system. The hoses direct generated vapors to the canister, 

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 Would the Proposed Changes to Gasoline Sulfur Content Affect Vehicle 

Emissions?

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 

volatile hydrocarbon fraction), CO, and most air toxics. The presence of sulfur in 

gasoline has a strong impact on these emissions, particularly NOX, due to its impact on 

proper catalyst operation. 
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Sulfur naturally occurs in crude oil and thus in gasoline. In vehicle catalytic 

converters, the precious metals that catalyze the reactions that convert the pollutants 

become significantly less efficient when sulfur is deposited (adsorbed) onto them. 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. At the time there were indications 

that sulfur reductions below 30 ppm may continue to 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 further. As a 

result, to minimize the cost of the Tier 2 program, the sulfur standard was not further 

reduced below 30 ppm. 

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 low sulfur fuel, relative to 32-ppm fuel.192 In particular, the study found a 

nearly 50 percent increase in NOX when sulfur was increased from 6 ppm to 32 ppm. 

Another recent study by Umicore showed reductions of 41 percent for NOX and 17 

percent for HC on a PZEV operating on fuel with 33-ppm and 3-ppm fuel.193 

A larger study recently completed by EPA confirmed these results, showing 

significant reductions in FTP-composite NOX (23 percent), CO (12 percent) and total HC 

(13 percent) on the 5-ppm fuel, relative to 28-ppm fuel. 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 59 percent reduction between 28 and 5-ppm fuel, consistent with the 

role of sulfur in catalyst degradation discussed above. Applying individual bag 

reductions to in-use activity patterns from EPA emission models suggests an overall NOX

reduction of nearly 40 percent on the road. 

Based on these studies, the benefits of the proposed Tier 3 sulfur standard are 

significant in two ways: they enable vehicles designed to the proposed 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 Would Emissions Be Reduced?

The proposed standards would reduce emissions of VOC, NOX (including NO2), 

direct PM2.5, CO, SO2, and air toxics. The proposed sulfur standards would reduce 

 

192 Regulatory Impact Analysis for the Control of Hazardous Air Pollutants from Mobile Sources Final 

Rule, EPA 420-R-07-002, Chapter 6

193 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
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emissions from the on-road fleet immediately upon implementation, so to reflect these 

early reductions, we present emission reductions in calendar year 2017. The proposed 

vehicle standards would begin to reduce emissions as the cleaner cars and trucks begin to 

enter the fleet in model year 2017. The magnitude of reduction would grow as more Tier 

3 vehicles enter the fleet. Therefore, we also present emission reductions in calendar year 

2030, when model year 2017 and later cars and trucks contribute nearly 90 percent of 

fleet-wide vehicle miles travelled. Although 2030 is the farthest year that is feasible for 

air quality modeling, the full reduction of the vehicle program would be realized after 

2030, when the fleet has fully turned over to Tier 3 vehicles. In Chapter 7 of the RIA, we 

present emission reductions projected in 2050, as well as additional calendar years 

between 2017 and 2030. 

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, and other fuel 

properties. We estimated emission reductions compared to a reference case that assumed 

partial RFS2 implementation by 2017, with full implementation in 2022 and beyond. 

The ethanol scenarios used for the reference and control cases were the “postEPAct/EISA” scenario defined in Chapter 7 of the RIA, reflecting a mix of E10 and E15 

in 2017, and E15 only in 2030. The reference case also assumed continuation of the Tier 

2 vehicle program indefinitely, and an average sulfur level of 30 ppm (10 ppm in 

California). 

As discussed throughout this preamble, implementation of the proposed Tier 3 

standards is aligned with the 2017 LD GHG standards to achieve significant criteria 

pollutant and GHG emissions reductions while providing regulatory certainty and 

compliance efficiency to the auto and oil industries. The 2017 LD GHG standards were 

still in a preliminary state of development (pre-proposal) at the time we finalized our 

assumptions for the Tier 3 emissions, air quality, and cost analyses, so we were not able 

to reflect them in these analyses. However, we continue to expect vehicle criteria 

pollutant performance to be neutral under the GHG program, because exhaust and 

evaporative emissions are not proportional to the amount of fuel burned; rather, our 

standards are expressed on a per-mile basis, not on a per-gallon basis. Vehicle criteria 

emissions are almost exclusively controlled by a vehicle’s emissions aftertreatment 

system and not by the efficiency of the engine. 

The majority of the NMOG that is emitted from a gasoline engine is generated 

during cold start, before the catalyst is lit off, and NOX is often created during higher load 

operation. Optimizing catalyst efficiency, minimizing thermal parasitics, minimizing fuel 

system leaks, and lower gasoline sulfur will be key enablers for all vehicles to meet the 

Tier 3 standards, regardless of the vehicle’s fuel efficiency. Because we do not expect 

the increase in fuel efficiency to result in lower criteria pollutant emissions, we did not 

claim in the 2017 LD GHG rule any reductions attributable to the ability of vehicles to 

meet lower criteria emission levels (see 77 FR 62899-62901, October 15, 2012). In other 

words, in the 2017 LD GHG rule, we assumed that, absent the proposed Tier 3 standards, 
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the light-duty fleet would continue to meet the Tier 2 standards. Thus, we believe that 

the inclusion of the light-duty GHG standards in our cost and benefit analyses for the 

proposed Tier 3 standards would have had little or no impact on the results or our

conclusions, as discussed in Sections 7.1.2 and 7.1.3.2.1 of the draft RIA. Nevertheless, 

for the final rulemaking we will include the LD GHG requirements in the analysis

baseline and request comment on the concept that the quantity of fuel burned by a vehicle 

does not affect the amount of criteria pollutants emitted. Further, EPA requests comment 

on alternative methods for verifying this concept in addition to the per-mile basis by

which the standards are currently set.

The analysis described here does account 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)

The analysis also accounts for many other national rules and standards. In addition, the 

modeling accounts for state and local rules including local fuel standards, 

Inspection/Maintenance programs, Stage II refueling controls, the National Low 

Emission Vehicle Program (NLEV), and the section 177 states LEV and LEVII 

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 2017 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 2017 are significant; for example, combined NOX and VOC emissions 

would be reduced by over 300,000 tons. By 2030, combined NOX and VOC emissions 

would be reduced by roughly 750,000 tons, one quarter of the onroad inventory. Many of 

the modeled air toxics would be significantly reduced as well, including benzene, 1,3-

butadiene, acetaldehyde, acrolein and ethanol (ranging from 20 to nearly 40 percent of 

the national onroad inventory by 2030). The relative reduction in overall emissions 

would 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 would have turned over 

to Tier 3 standards, we estimate the Tier 3 program would reduce onroad emissions of 

NOX and VOC nearly 40 percent from the level of emissions projected without Tier 3 

controls. 
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Table III-1 Estimated Emission Reductions from the Proposed Tier 3 Standards 

(Annual U.S. short tons) a

2017 2030

Tons % of 

Onroad 

Inventory

Tons % of 

Onroad 

Inventory

NOX 284,381 8% 524,790 28%

VOC 44,782 3% 226,028 23%

CO 746,683 4% 5,765,362 30%

Direct PM2.5 121 0.1% 7,458 10%

Benzene 1,625 4% 8,582 36%

SO2 16,261 51% 17,267 51%

1,3-Butadiene 322 5% 1,087 37%

Formaldehyde 727 3% 2,707 12%

Acetaldehyde 762 3% 4,414 26%

Acrolein 23 1% 184 15%

Ethanol 2,684 2% 27,821 24%

a This analysis assumed emissions reductions from the Tier 3 vehicle standards would occur in 

all states. For the final rule we will account for LEV III vehicle standards in states that have 

subsequently adopted it.

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 proposed sulfur standards would 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 would also be expected to 

decrease from the fleet of older (pre-Tier 2) light-duty vehicles as well as heavy-duty

gasoline vehicles,194 although at 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 2017 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 proposed 

sulfur standards, total onroad NOX emissions are projected to drop 8 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 2017. The relative reduction 

 

194 Rao, V. (2001) Fuel Sulfur Effects on Exhaust Emissions: Recommendations for MOBILE6, EPA420-

R-01-039
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grows as cleaner vehicles turn over into the fleet. By 2030, we project that the reduction 

in overall onroad NOX inventory would be close to 30 percent.

Table III-2 Projected NOX Reductions from Tier 3 Program (Annual U.S. Tons)a

2017 2030

Total reduction 284,381 524,790

Reduction from pre-Tier 3 

fleet due to sulfur standard

264,653 66,286

Reduction from Tier 3 fleet 

due to vehicle and sulfur 

standards 

19,728 458,504

Percent reduction in 

onroad NOX emissions

8% 28%

a This analysis assumed emissions reductions from the Tier 3 vehicle standards would occur in all states.

For the final rule we will account for LEV III vehicle standards in states that have subsequently adopted it.

2. VOC

Table III-3 shows the reduction in VOC emissions, in annual short tons, projected 

in calendar years 2017 and 2030 resulting from the proposed standards. In 2017, as with 

NOX, we project reductions from the pre-Tier 3 fleet with the proposed fuel standards. 

By 2030 the reduction in overall onroad VOC emissions would be over 20 percent, the 

majority of this from the Tier 3 fleet. The proposed evaporative standards are projected to 

account for roughly one quarter of the overall vehicle program reduction in 2030. 

Table III-3 Projected VOC Reductions from Tier 3 Program (Annual U.S. Tons)a

2017 2030

Total reduction 44,782 226,028

Reduction from pre-Tier 3 

fleet due to sulfur standard

39,561 13,739

Reduction from Tier 3 fleet 

due to vehicle and sulfur 

standards 

5,222 212,289

Exhaust 41,433 168,264

Evaporative 3,349 57,764

Percent reduction in 

onroad VOC emissions

3% 23%

a This analysis assumed emissions reductions from the Tier 3 vehicle standards would occur in all states.

For the final rule we will account for LEV III vehicle standards in states that have subsequently adopted it.

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. Based on research showing sizeable CO 

reductions from lower sulfur fuel, the immediate reductions in the onroad fleet from 
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sulfur control are also significant. The CO exhaust standards are projected to reduce 

onroad CO emissions 30 percent by 2030. 

Table III-4 Projected CO Reductions from Tier 3 Program (Annual U.S. Tons)

2017 2030

Total reduction 746,683 5,765,362

Reduction from pre-Tier 3 

fleet due to sulfur standard

608,502 139,074

Reduction from Tier 3 fleet 

due to vehicle and sulfur 

standards

138,181 5,626,288

Percent reduction in 

onroad CO emissions

4% 30%

a This analysis assumed emissions reductions from the Tier 3 vehicle standards would occur in all states.

For the final rule we will account for LEV III vehicle standards in states that have subsequently adopted it.

4. Direct PM2.5

Reductions in direct emissions of PM2.5 are projected to result solely from the 

proposed vehicle tailpipe standards, so meaningful reductions are realized mainly as the 

fleet turns over. By 2030, we project a reduction of about 7,500 tons annually, which 

represents approximately 10 percent of the onroad direct PM2.5 inventory. However, 

since the PM standards are mainly focused on improving engine durability through the 

end of a vehicle’s useful life, the relative reduction in onroad emissions is projected to 

grow to 17 percent with full fleet turnover in 2050. Reductions in NOX and VOC 

emissions would 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 would be reduced by the proposed 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. 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 

2017

% Reduction 

in Onroad 

Emissions

Tons Reduced in 

2030

% Reduction in 

Onroad Emissions

Acetaldehyde 762 3% 4,414 26%

Formaldehyde 727 3% 2,707 12%

Acrolein 23 1% 184 15%

1,3-Butadiene 322 5% 1,087 37%
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Benzene 1,625 4% 8,581 36%

Naphthalene 96 2% 420 17%

Ethanol 2,684 2% 27,821 24%

a This analysis assumed emissions reductions from the Tier 3 vehicle standards would occur in all states.

For the final rule we will account for LEV III vehicle standards in states that have subsequently adopted it.

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 (Appendix 7A in the 

draft RIA). As shown, in 2030 the overall onroad inventory of total toxics would be 

reduced by over 20 percent, with nearly one third of the vehicle program reductions 

coming from the proposed evaporative standards. 

Table III-6 Reductions in Total Mobile Source Air Toxics (Annual U.S. Tons)

2017 2030

Total reduction 15,156 89,685

Reduction from pre-Tier 3 

fleet due to sulfur standard

12,452 5,022

Reduction from Tier 3 fleet 

due to vehicle and sulfur 

standards

2,683 84,663

Exhaust 13,748 64,144

Evaporative 1,408 25,541

Percent reduction in 

onroad toxics emissions

3% 23%

a This analysis assumed emissions reductions from the Tier 3 vehicle standards would occur in all states.

For the final rule we will account for LEV III vehicle standards in states that have subsequently adopted it.

6. SO2

SO2 emissions from mobile sources are a direct function of sulfur in the fuel, and 

reducing sulfur in gasoline would 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.195

Table III-7 Projected SO2 Reductions from Tier 3 Program (Annual U.S. Tons)

2017 2030

Total reduction 16,261 17,267

Reduction from onroad 

vehicles due to sulfur 

15,494 16,370

 

195 U.S. Energy Information Administration (2011), Annual Energy Outlook 2011, DOE/EIA-0383(2011)
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standard

Reduction from off-road 

equipment due to sulfur 

standard

767 897

Percent reduction in 

onroad SO2 emissions

51% 51%

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 due to the 

proposed sulfur and tailpipe standards. A study conducted by the University of 

California at Riverside found a 29 percent reduction in N2O emissions over the FTP when 

sulfur was reduced from 30 to 5 ppm,196 while EPA research described in Section IV.A 

on sulfur effects found a 25 percent reduction in CH4 emissions when sulfur was reduced 

from 28 to 5 ppm. Several studies have established correlations between reductions in 

tailpipe NOX emissions and reductions in N2O from gasoline cars and trucks, 197,198,199 as 

well as correlations between reductions in tailpipe HC emissions and reductions in 

CH4.

200,201 One such study (Behrentz et al.) reported an N2O: NOX ratio of 0.095±0.035, 

and supported the application of N2O: NOX ratios to NOX emissions as a reasonable 

method for estimating N2O emission inventories. As detailed in RIA Chapter 7.3, a range 

of N2O reductions is bounded by applying this ratio to NOX reductions projected for this 

proposal (from Table III-1), and applying the UC Riverside sulfur results to MOVES 

N2O inventories for pre-Tier 3 vehicles. Using a 100-year global warming potential of 

298 for N2O according to the 2007 IPCC AR4, 202 the range of reductions calculated for 

N2O is from 2.9 to 7.3 million metric tons of carbon dioxide equivalent (MMTCO2e) in 

2017, growing to 12.3 to 13.5 MMTCO2e in 2030. MOVES can be used to directly

estimate CH4 reductions from the sulfur and vehicle standards, estimating an additional 

 

196 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 

197 Michaels, H. (1998) Emissions of Nitrous Oxide from Highway Mobile Sources, U.S. EPA EPA420-R98-009 

198 Behrentz, et al. (2004), Measurements of nitrous oxide emissions from light-duty motor vehicles: a pilot 

study Atmospheric Environment 4291-4303 

199 Meffert, et. al (2000) Analysis of Nitrous Oxide Emissions from Light Duty Passenger Cars, SAE 2000-

01-1952

200 Meszler, D. (2004), Light Duty Vehicle Methane and Nitrous Oxide Emissions: Greenhouse Gas 

Impacts Study for Northeast States Center for a Clean Air Future

201 Graham, L. Greenhouse Gas Emissions from 1997-2005 Model Year Light Duty Vehicles Environment 

Canada ERMD Report #04-44 

202 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 

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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0.1 MMTCO2e reduction in 2017, growing to 0.5 MMTCO2e in 2030. The range of 

total GHG reductions from the Tier 3 rule is 3.0 to 7.4 MMTCO2e in 2017, growing to 

12.8 to 14.0 MMTCO2e in 2030. 

These reductions would be offset to some degree by CO2 emissions associated 

with higher energy use required in the process of removing sulfur within the refinery. To 

assess the potential refinery permitting implications of the Tier 3 proposal, we calculated 

the CO2 emission impacts on a refinery-by-refinery basis. We used the projected 

refinery-specific changes from our refinery-by-refinery modeling (see Chapter 5 of the 

draft RIA) to estimate changes in process energy and then applied emission factors that 

correspond to those changes. The results showed an increase of up to 4.6 MMTCO2e in 

2017 for all U.S. refineries complying with the lower sulfur standards assuming that the 

proposed sulfur standards are fully phased-in.

204

 The actual increase is expected to be

considerably lower, since this is a permitting analysis and refineries will not be operating 

at their permit capacity. The actual increase will also be a function of several factors, 

including technology options selected by the refineries and the projected use of 

averaging, banking and trading in avoiding the need for investments at some refineries. 

As a result, 4.6 MMTCO2e represents an upper-bound estimate of the possible increase in 

refinery CO2 emissions due to the need for additional process heat and hydrogen 

production to enable the additional hydrotreating required. 

In 2017, the range of potential decrease in CH4 and N2O emissions overlaps with 

the range of projected increase in CO2 from refinery processes, suggesting that a net 

increase or decrease in GHG emissions cannot be quantified with certainty. However, we 

estimate the program would result in net GHG reductions as the program continues into 

the future, as shown by our 2030 estimates. 

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 we have 

designed the program to address – 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. However, 

there may be some slight reduction of vehicle mass if manufacturers explore lighter 

exhaust manifold materials in order to reduce thermal mass and promote earlier catalyst 

light-off. EPA invites comments on any potential impacts of the proposed Tier 3 

program on vehicle CO2 emissions and fuel economy.

C. How Would Air Pollution Be Reduced? 

Reductions in emissions of NOX, VOC, PM2.5 and air toxics expected as a result 

of the proposed Tier 3 standards are projected to lead to significant decreases in ambient 

concentrations of ozone, PM2.5, and air toxics. The results of our air quality modeling of 

the impacts of the Tier 3 proposal are summarized in the following section. The air 

 

204 Keller, P. (February, 2013). New Source Review Permitting Impact Analysis for Proposed Tier 3 

Gasoline Program. Memorandum to the docket.
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quality modeling predicts significant improvements in ozone concentrations due to the 

proposed Tier 3 standards. Ambient PM2.5 and NO2 concentrations are also expected to 

improve as a result of the proposed Tier 3 program. Decreases in ambient concentrations 

of air toxics are projected with the proposed 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 proposed standards. 

1. Ozone

The air quality modeling done for this proposal projects that in 2017, with all 

current controls in effect but excluding the emissions changes expected to occur as a 

result of this proposed action or any other additional controls, at least 40 counties, with a 

projected population of almost 50 million people, would have projected design values 

above the level of the 2008 8-hour ozone standard of 75 ppb. Even in 2030 the modeling 

projects that in the absence of additional controls there would be 12 counties with a 

population of almost 32 million people with projected design values above the level of

the 2008 8-hour ozone standard of 75 ppb. Since the emission changes from this 

proposal go into effect during the period when some areas are still working to attain the 

ozone NAAQS, the projected emission changes would help state and local agencies in 

their effort to attain and maintain the ozone standard. 

Air quality modeling indicates ozone design value concentrations would decrease 

dramatically in many areas of the country as a result of this action and in some places 

those decreases would be enough to change the projected design values from being above 

the NAAQS to being below the NAAQS. The decreases in ozone design values are likely

due to projected tailpipe reductions in NOX and VOCs from reductions in fuel sulfur and 

engine controls. 

In 2017, the majority of the design value decreases are between 0.5 and 1.0 ppb. 

The projected population-weighted average design value concentration without the 

proposed rule is 71.3 ppb in 2017. The proposed rule would also reduce the projected 

ozone design values in three counties from above the level of the standard to below. 

These three counties are Bucks County in Pennsylvania, Arlington County in Virginia 

and St Louis County in Missouri. The projected population in these three counties in 

2017 is almost 2 million people. In 2030, the proposed rule would result in larger 

decreases in ozone design values, with the majority of counties projecting decreases of 

between 1.0 and 1.5 ppb, and over 200 more counties with decreases greater than 1.5 ppb. 

The projected population-weighted average design value concentration without the 

proposed rule is 66.7 ppb in 2030. There are also two more counties whose projected 

design values would be reduced from above the level of the ozone standard to below by

the proposed rule in 2030. These counties are Hudson County in New Jersey and 

Brazoria County in Texas. The projected population in these two counties in 2030 is over 

1 million people.

Table III-8 and Table III-9 show the average change in 2017 and 2030 8-hour 

ozone design values for: (1) all counties with 2005 baseline design values, (2) counties
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with 2005 baseline design values that exceeded the 2008 ozone standard, (3) counties 

with 2005 baseline design values that did not exceed the 2008 standard, but were within 

10 percent of it, (4) counties with 2017/2030 design values that exceeded the 2008 ozone 

standard, and (5) counties with 2017/2030 design values that did not exceed the standard, 

but were within 10 percent of it. Counties within 10 percent of the standard are intended 

to reflect counties that although not violating the standards, will also be impacted by

changes in ozone as they work to ensure long-term maintenance of the ozone NAAQS. 

All of these metrics show a decrease in 2017 and 2030, indicating in five different ways 

the overall improvement in air quality. 

On a population-weighted basis, the average modeled future-year 8-hour ozone 

design values are projected to decrease by 0.47 ppb in 2017 and 1.55 ppb in 2030. On a 

population-weighted basis design values in those counties that are projected to be above 

the 2008 ozone standard in 2017 and 2030 are projected to decrease by 0.30 and 1.62 ppb 

respectively due to the proposed standards. 

Table III-8 Average Change in Projected 8-hour Ozone Design Value in 2017c

Averagea Number 

of U.S. 

Counties

2020 

Populationb

Change in 

2017 design 

value (ppb)

All 676 238,026,106 -0.50

All, population-weighted -0.47

Counties whose 2005 base year is violating the 2008 

8-hour ozone standard

393 176,910,535 -0.56

Counties whose 2005 base year is violating the 2008 

8-hour ozone standard, population-weighted

-0.51

Counties whose 2005 base year is within 10 percent 

of the 2008 8-hour ozone standard

201 40,516,171 -0.47

Counties whose 2005 base year is within 10 percent 

of the 2008 8-hour ozone standard, populationweighted

-0.42

Counties whose 2017 control case is violating the 

2008 8-hour ozone standard

37 47,659,433 -0.35

Counties whose 2017 control case is violating the 

2008 8-hour ozone standard, population-weighted

-0.30

Counties whose 2017 control case is within 10 

percent of the 2008 8-hour ozone standard

124 68,625,934 -0.51

Counties whose 2017 control case is within 10 

percent of the 2008 8-hour ozone standard, 

population-weighted

-0.49

a Averages are over counties with 2005 modeled design values 

b

Population numbers based on Woods & Poole data. Woods & Poole Economics, Inc. 2001. Population 

by Single Year of Age CD.
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c This analysis assumed emissions reductions from Tier 3 vehicle standards would occur in all states and 

did not account for emission reductions associated with LEV III vehicle standards in California and other 

states that have subsequently adopted it. The analysis for the final rule will account for LEV III vehicle 

standards.

Table III-9 Average Change in Projected 8-hour Ozone Design Value in 2030c

Averagea Number 

of U.S. 

Counties

2030 

Populationb

Change in 

2030 design 

value (ppb)

All 676 261,497,900 -1.35

All, population-weighted -1.55

Counties whose 2005 base year is violating the 2008 

8-hour ozone standard

393 194,118,748 -1.54

Counties whose 2005 base year is violating the 2008 

8-hour ozone standard, population-weighted

-1.69

Counties whose 2005 base year is within 10 percent 

of the 2008 8-hour ozone standard

201 44,436,103 -1.18

Counties whose 2005 base year is within 10 percent 

of the 2008 8-hour ozone standard, populationweighted

-1.25

Counties whose 2030 control case is violating the 

2008 8-hour ozone standard

10 30,619,714 -1.49

Counties whose 2030 control case is violating the 

2008 8-hour ozone standard, population-weighted

-1.62

Counties whose 2030 control case is within 10 

percent of the 2008 8-hour ozone standard

40 21,541,863 -1.37

Counties whose 2030 control case is within 10 

percent of the 2008 8-hour ozone standard, 

population-weighted

-1.50

a Averages are over counties with 2005 modeled design values 

b

Population numbers based on Woods & Poole data. Woods & Poole Economics, Inc. 2001. Population 

by Single Year of Age CD.

c This analysis assumed emissions reductions from Tier 3 vehicle standards would occur in all states and 

did not account for emission reductions associated with LEV III vehicle standards in California and other 

states that have subsequently adopted it. The analysis for the final rule will account for LEV III vehicle 

standards.

2. Particulate Matter

The air quality modeling conducted for this proposal projects that in 2030, with 

all current controls in effect but excluding the emissions changes expected to occur as a 

result of this proposal or any other additional controls, at least 14 counties, with a 

projected population of over 28 million people, would have projected design values 

above the level of the annual standard of 12 μg/m3 and at least 21 counties, with a 
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projected population of over 31 million people, would have projected design values 

above the level of the 24-hour standard of 35 μg/m3.205 Since the emission changes from 

this proposed action would go into effect during the period when some areas are still 

working to attain the PM2.5 NAAQS, the projected emission changes would be useful to 

state and local agencies in their effort to attain and maintain the PM2.5 standard. 

The proposed rule would reduce 24-hour and annual PM2.5 design values in 2030. 

Annual PM2.5 design values in the majority of modeled counties would decrease by

between 0.01 and 0.05 μg/m3 and in over 100 additional counties design values are 

projected to decrease by greater than 0.05 μg/m3. The projected population-weighted 

average design value concentration without the proposed rule is 9.5 μg/m3in 2030. The 

average modeled future-year annual PM2.5 design values in 2030 decrease by 0.06 μg/m3

on a population-weighted basis. Design values in those counties that are projected to be 

above the annual PM2.5 standard in 2030 decrease even more, by 0.11 μg/m3on a 

population-weighted basis, due to the proposed standards. In addition, the average 

modeled future-year 24-hour PM2.5 design values in 2030 decrease by 0.20 μg/m3 on a 

population-weighted basis. The projected population-weighted average design value 

concentration without the proposed rule is 24.3 μg/m3in 2030. The decreases in PM2.5

design values are likely due to the projected tailpipe reductions in primary PM2.5, NOX

and VOCs. The proposed rule has little impact on PM2.5 design values for the majority of 

counties in 2017, although our air quality modeling underestimated the PM decreases that 

would result from this proposal (see Section 7.4.2.3 of the draft RIA for more detail). 

Table III-10 and Table III-11 present the average change in 2030 annual and 24-

hour PM2.5 design values for: (1) all counties with 2005 baseline design values, (2) 

counties with 2005 baseline design values that exceeded the PM2.5 standard, (3) counties 

with 2005 baseline design values that did not exceed the standard, but were within 10 

percent of it, (4) counties with 2030 design values that exceeded the PM2.5 standard, and 

(5) counties with 2030 design values that did not exceed the standard, but were within 10 

percent of it. Counties within 10 percent of the standard are intended to reflect counties 

that although not violating the standards, will also be impacted by changes in PM2.5 as 

they work to ensure long-term maintenance of the annual and/or 24-hour PM2.5 NAAQS. 

All of these metrics show a decrease in 2030. On a population-weighted basis, there is a 

0.06 μg/m3decrease in the average modeled future-year annual PM2.5 design values in 

2030 and a decrease of 0.11 μg/m3in those counties that are projected to be above the 

annual PM2.5 standard in 2030. In addition, the average population-weighted modeled 

future-year 24-hour PM2.5 design values are projected to decrease by 0.20 μg/m3due to 

the proposed standards and design values in those counties that are projected to be above 

the 24-hour PM2.5 standard in 2030 would decrease by 0.32 μg/m3.

 

205 The projections from the modeling analysis for the Tier 3 proposal differ from what was presented in the 

recent PM NAAQS RIA (http://www.epa.gov/pm/actions.html). The differences in modeling between the 

analyses stem primarily from the difference in modeling platform and the different years being evaluated 

(2020 vs. 2030).
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Table III-10 Average Change in Projected Annual PM2.5 Design Values in 2030c

Averagea Number of U.S. 

Counties

2030 Population Change in 2030 

design value 

(g/m3) 

All 576 247,415,381 -0.05

All, population-weighted -0.06

Counties whose 2005 base 

year is violating the annual 

PM2.5 standard

314 152,109,569

-0.05

Counties whose 2005 base 

year is violating the annual 

PM2.5 standard, populationweighted -0.07

Counties whose 2005 base 

year is within 10 percent of 

the annual PM2.5 standard

83 31,863,376

-0.05

Counties whose 2005 base 

year is within 10 percent of 

the annual PM2.5 standard, 

population-weighted -0.05

Counties whose 2030 control 

case is violating the annual 

PM2.5 standard 

14 28,624,758

-0.11

Counties whose 2030 control 

case is violating the annual 

PM2.5 standard, populationweighted -0.10

Counties whose 2030 control 

case is within 10 percent of 

the annual PM2.5 standard

28 23,840,272

-0.07

Counties whose 2030 control 

case is within 10 percent of 

the annual PM2.5 standard, 

population-weighted -0.09

a Averages are over counties with 2005 modeled design values 

b

Population numbers based on Woods & Poole data. Woods & Poole Economics, Inc. 2001. Population 

by Single Year of Age CD.

c This analysis assumed emissions reductions from Tier 3 vehicle standards would occur in all states and 

did not account for emission reductions associated with LEV III vehicle standards in California and other 

states that have subsequently adopted it. The analysis for the final rule will account for LEV III vehicle 

standards.
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Table III-11 Average Change in Projected 24-hour PM2.5 Design Values in 2030c

Averagea Number 

of U.S. 

Counties

2030 

Populationb

Change in 

2030 design 

value 

(μg/m3)

All

569 245,111,480

-0.16

All, population-weighted -0.20

Counties whose 2005 base year is violating the 2006 

24-hour PM2.5 standard

108 91,474,036

-0.29

Counties whose 2005 base year is violating the 2006 

24-hour PM2.5 standard, population-weighted -0.27

Counties whose 2005 base year is within 10 percent 

of the 2006 24-hour PM2.5 standard

140 53,990,060

-0.18

Counties whose 2005 base year is within 10 percent 

of the 2006 24-hour PM2.5 standard, populationweighted -0.21

Counties whose 2030 control case is violating the 

2006 24-hour PM2.5 standard

21 31,002,272

-0.50

Counties whose 2030 control case is violating the 

2006 24-hour PM2.5 standard, population-weighted -0.32

Counties whose 2030 control case is within 10 

percent of the 2006 24-hour PM2.5 standard

7 4,212,913

-0.37

Counties whose 2030 control case is within 10 

percent of the 2006 24-hour PM2.5 standard, 

population-weighted -0.50

a Averages are over counties with 2005 modeled design values 

b

Population numbers based on Woods & Poole data. Woods & Poole Economics, Inc. 2001. Population 

by Single Year of Age CD.

c This analysis assumed emissions reductions from Tier 3 vehicle standards would occur in all states and 

did not account for emission reductions associated with LEV III vehicle standards in California and other 

states that have subsequently adopted it. The analysis for the final rule will account for LEV III vehicle 

standards.

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 

proposal, 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 

proposal is available in Section 7.2.1 of the draft RIA. 
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4. Air Toxics

Our modeling indicates that the impacts of proposed Tier 3 standards include 

generally small decreases in ambient concentrations of air toxics, especially in urban 

areas, with notable nationwide reductions in benzene. Although reductions are greater in 

2030 (when Tier 3 cars and trucks would contribute nearly 90 percent of fleet-wide 

vehicle miles travelled) than in 2017(the first year of the proposed program), our 

modeling projects there would be small immediate reductions in ambient concentrations 

of air toxics due to the proposed sulfur controls in 2017. Furthermore, the full reduction

of the vehicle program would be realized after 2030, when the fleet has fully turned over 

to Tier 3 vehicles. Air toxics pollutants dominated by primary emissions (or a decay

product of a directly emitted pollutant) have the largest impacts, rather than air toxics that 

primarily result from photochemical transformation. Specifically, in 2030, our modeling 

projects that the proposal would 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, 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 proposed rule would 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 5 percent in 2030 as a result of the proposal. Decreases in ethanol 

concentrations are expected due to reductions in VOC as a result of the proposed 

standards. Changes in ambient acetaldehyde concentrations are generally less than 1 

percent across the U.S., although the proposal may decrease acetaldehyde concentrations 

in some urban areas by 1 to 2.5 percent in 2030. 

Although the reductions in ambient air toxics concentrations expected from the 

proposed Tier 3 standards are generally small, they are projected to benefit the majority

of the U.S. population. As shown in Table III-12, over 80 percent of the total U.S. 

population is projected to experience a decrease in ambient benzene and acrolein 

concentrations of at least 2.5 percent, with more than 90 percent of the populations 

projected to experience 1,3-butadiene concentrations of similar magnitude. Over 80 

percent of the U.S population is projected to experience at least a 1 percent decrease in 

ambient ethanol concentrations, and over 60 percent would experience a similar decrease 

in ambient formaldehyde concentrations with the proposed standards. 

Table III-12 Percent of Total Population Experiencing Changes in Annual Ambient 

Concentrations of Toxic Pollutants in 2030 as a Result of the Proposed Standardsa

Percent Change Benzene Acrolein 1,3-Butadiene Formaldehyde Ethanol Acetaldehyde

≤ -50

> -50 to ≤ -25 0.1%

> -25 to ≤ -10 2.8% 0.7% 56.8%

> -10 to ≤ -5 23.7% 36.8% 30.8%
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> -5 to ≤ -2.5 54.5% 43.7% 7.1% 1.2% 33.0% 0.3%

> -2.5 to ≤ -1 17.7% 15.3% 3.4% 63.2% 55.3% 25.1%

> -1 to < 1 1.4% 3.5% 1.7% 35.6% 11.6% 74.6%

≥ 1 to < 2.5 0.0%

≥ 2.5 to < 5

≥ 5 to < 10

≥ 10 to < 25

≥ 25 to < 50

≥ 50 

a This analysis assumed emissions reductions from Tier 3 vehicle standards would occur in all states and did not 

account for emission reductions associated with LEV III vehicle standards in California and other states that have 

subsequently adopted it. The analysis for the final rule will account for LEV III vehicle standards.

5. Visibility

Air quality modeling conducted for this proposed action was used to project 

visibility conditions in 139 mandatory class I federal areas across the U.S. The results 

show that in 2030 all the modeled areas would continue to have annual average deciview 

levels above background and the proposed rule would improve visibility in all these 

areas.206 The average visibility at all modeled mandatory class I federal areas on the 20 

percent worst days is projected to improve by 0.04 deciviews, or 0.28 percent, in 2030. 

Section 7.2.5.5 of the draft 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 proposed standards. The standards would result in annual percent decreases 

of greater than 5 percent in most major urban areas and greater than 7 percent in a few 

areas. In addition, smaller decreases, in the 1 to 1.5 percent range, would occur over 

most of the rest of the country. The impacts of the proposed standards on sulfur 

deposition are smaller, ranging from no change to decreases of over 2 percent in some 

areas. For maps of 2030 deposition impacts and additional information on these impacts 

see Section 7.2.5.6 of the draft RIA. 

 

206 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.
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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.207

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 

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.208,209,210,211 Household-level stressors such as parental smoking and 

relationship stress also may increase susceptibility to the adverse effects of air 

pollution.212,213

 

207 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

208 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]

209 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]

210 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.

211 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]

212 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]

213 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 
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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 214,215,216,217,218,219

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.”220 We 

 

hydrocarbons, environmental tobacco smoke and asthma. Respir Med (In press). 

doi:10.1016/j.rmed.2010.11.022 [Online at http://dx.doi.org]

214 Marshall, J.D. (2008) Environmental inequality: air pollution exposures in California’s South Coast Air 

Basin.

215 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]

216 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]

217 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]

218 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]

219 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.

220 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. As such, highways represent the overwhelming majority of transportation facilities 

described by this factor in the AHS.
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analyzed whether there were differences between houses and householders in such 

locations and those not in them.221 We found that houses with a nonwhite householder 

were 22-34 percent more likely to be located within 300 feet of these large 

transportation facilities, while houses 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.222 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.223 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 reduction of near-roadway concentrations of many pollutants, discussed 

above, is likely to help in mitigating this disparity in racial, ethnic, and economicallybased exposures.

IV. Proposed Vehicle Emissions Program

In the more than 10 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 key exhaust emissions, especially hydrocarbons, 

nitrogen oxides (NOX), and particulate matter (PM). 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 progress in vehicle technology 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. 

 

221 Bailey, C. (2011) Demographic and Social Patterns in Housing Units Near Large Highways and other 

Transportation Sources. Memorandum to docket.

222 http://nces.ed.gov/ccd/

223 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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Extensive data from existing Tier 2 (and California LEV II) vehicles show the 

opportunity for further reductions, especially in addressing emissions produced at startup, emissions under high-speed, high-load conditions, the effects of sulfur in gasoline, the 

effects of increased oil consumption, and the effects of vehicle and control systems age. 

For these reasons, we are proposing more stringent standards designed to reduce 

emissions, primarily non-methane organic gases (NMOG), NOX, and PM from new 

vehicles. As discussed in detail below and in the draft RIA, we have concluded that, in 

conjunction with the reductions in fuel sulfur proposed in this action, the proposed 

vehicle emissions standards are feasible and cost-effective across the fleet in the proposed 

timeframe. We believe that simultaneous reductions in fuel sulfur would be a key factor 

in enabling the entire fleet of light-duty vehicles to meet the proposed emission standards 

in-use, throughout the life of the vehicle.

This section describes in detail the proposed 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 heavyduty vehicles (HDVs). Sections IV.A and B discuss the proposed tailpipe emission 

standards and time lines, and other provisions for new light-duty vehicles and MDPVs 

and for new heavy-duty vehicles up to 14,000 lbs Gross Vehicle Weight Rating 

(GVWR). Section IV.C presents the proposed evaporative emissions standards and 

program as well as proposed improvements to the existing Onboard Diagnostics (OBD) 

provisions. In Section IV.D, we describe our proposal to update our federal certification 

fuel to better match today’s in-use fuel and to be forward-looking with respect to 

potential future gasoline ethanol and sulfur content. We also discuss in this section 

proposed compliance flexibilities for small companies and small-volume manufacturers 

(IV.E) and test procedure and other compliance provisions (IV.F). 

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

Medium-Duty Passenger Vehicles

1. Overview

The proposed Tier 3 standards are very similar in structure to those in the Tier 2 

program. As with the Tier 2 program, the proposed standards would apply to all LDVs 

and LDTs below 8,500 lbs GVWR, and MDPVs (8,500 to 10,000 lbs GVWR). (We 

discuss the proposed standards for heavy-duty vehicles up to 14,000 lbs GVWR other 

than MDPVs, in Section IV.B below.) Also as with Tier 2, manufacturers would select 

from several “bins” of emission standards such that the average of their vehicles’ 

emissions complies with the proposed fleet-average standards. 

In the discussions of the various elements of our proposed program for light- and 

heavy-duty vehicles throughout this preamble, we describe how the provisions would be 

consistent with the California Air Resources Board (CARB) LEV III program. 224 Auto 

 

224 LEV III program as approved by the California Air Resources Board, January 2012
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manufacturers have stressed to us the importance of their being able to design and 

produce a single fleet of vehicles in all 50 states that would comply with requirements 

under the Tier 3 program and the LEV III program, as well as greenhouse gas/CAFE 

requirements in the same timeframe. Consistency among the federal and California 

programs means that special versions of vehicles with different emission control 

hardware and calibrations would not be necessary for different geographic areas. This 

would allow manufacturers to avoid the additional costs of parallel design, development, 

calibration, and manufacturing. Consistency among programs would also eliminate the 

need to supply aftermarket parts for repair of multiple versions of a vehicle. We believe 

that the most cost-effective national program will result from close coordination of 

CARB LEV III and federal Tier 3 program elements and their implementation. To that 

end, we worked closely with CARB and the vehicle manufacturers, both individually and 

through their trade associations, to align the two programs. 

The Tier 3 program we are proposing is identical to LEV III in most major 

respects for both light-duty and heavy-duty vehicle exhaust and evaporative emissions

requirements, as discussed in detail below in this section. The levels and the timing of 

the light-duty and heavy-duty declining fleet-average NMOG+NOx standards that we are 

proposing would be identical to those in LEV III. Also, the Tier 3 emissions bins to 

which manufacturers would certify individual vehicle models in order to comply with the 

average standards, for both light- and heavy-duty vehicles, would also be identical to 

those in LEV III. Similarly, the proposed Tier 3 per-vehicle PM standards match LEV III 

standards through MY 2024. In addition, our proposed primary evaporative emissions 

standards and onboard diagnostics requirements are also identical to the LEV III 

requirements. 

We note there are a few proposed Tier 3 provisions that CARB and EPA 

understand would be different, for reasons discussed below. Specifically, these include 

the LEV III program and our proposed Tier 3 program would have different light-duty

PM requirements late in the program (i.e., after MY 2024 (IV.A.3.b.)), would require 

different test fuels (E10 and E15, respectively (IV.A.3.c)), and only EPA would have an 

evaporative leak test (IV.C.5.b). EPA and CARB will continue to work toward 

additional consistency between our programs whenever practicable as both programs are 

implemented. Beyond these three provisions, the differences between the programs 

would not be major and would exist only in the early transitional years of the Tier 3 

program. These differences would result from the fact that the LEV III requirements 

begin slightly earlier and that a limited phase-in of some provisions would be necessary

for a smooth transition to overall aligned programs. These temporary differences would 

include the process for how early compliance credits would be generated and used (e.g., 

Section IV.A.7.a); how quickly manufacturers would need to move toward certifying all 

of their vehicle models to longer useful-life values (e.g., Section IV.A.7.b) and on the 

new test fuel (e.g., Section IV.A.7.c); and transitional emissions bins to facilitate the 

transition from Tier 2 to Tier 3 (IV.A.7.m). Similarly, the primary Tier 3 evaporative 

standards would have a brief phase in period, temporarily resulting in requirements that 

would be slightly different from those in LEV III.
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The proposed Tier 3 program is designed primarily to reduce exhaust and 

evaporative emissions during summer ambient temperature conditions when NMOG, 

NOX and PM emissions contribute to air quality concerns. We are not proposing new 

emission requirements for any vehicle or fuel over the cold temperatures test cycles (i.e., 

the 20 °F cold CO and NMHC tests). However, we seek comment on the need for doing 

so, including vehicles operating on E85 fuel, and on the appropriate form and level for 

any such cold-temperature requirements. 

2. Summary of Proposed FTP and SFTP Tailpipe Standards

We are proposing a comprehensive program that would address the key pollutants 

of concern. We are proposing new standards for the sum of NMOG and NOX emissions, 

presented as NMOG+NOX, and PM. As discussed in Section III above, these proposed 

standards would result in very significant improvements in vehicle emissions from the 

levels of the Tier 2 program. For these pollutants, we are proposing standards as 

measured on test procedures that represent a range of vehicle operation, including the 

Federal Test Procedure (FTP) and the Supplemental Federal Test Procedure (SFTP). 

Unless otherwise specified, the proposed FTP and SFTP standards would apply to 

vehicles operating on gasoline, diesel, and alternative fuels, including both flexible fuel 

and dedicated alternative fuel vehicles.

The proposed FTP and SFTP NMOG+NOX standards would be fleet-average 

standards, meaning that the manufacturer would calculate the average emissions of the 

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

for that model year. The proposed fleet average standards for NMOG+NOX evaluated 

over the FTP are summarized in Table I-1. (For comparison, the average NMOG and 

NOX standard for the Tier 2 program, when added together, equal 160 mg/mi). The 

standards would begin in MY 2017 at a level representing a 46 percent reduction from 

the current Tier 2 requirements for lighter vehicles and would become increasingly 

stringent, culminating in an 81 percent reduction in MY 2025. The proposed FTP 

NMOG+NOX program includes separate fleet average standards for lighter and heavier 

vehicles that would converge at 30 milligrams per mile (mg/mi) in MY 2025 and 

later.225,226

Manufacturers would determine their fleet average FTP NMOG+NOX emission 

values based on the per-vehicle “bin standards” to which they certified each vehicle 

model. As with the Tier 2 program, manufacturers would be free to choose to certify

vehicles to any of the bins, so long as the sales-weighted average of the NMOG+NOX

 

225 The proposed declining NMOG+NOX fleet-average standards would consist of one set of declining 

standards that would apply to light-duty vehicles (LDVs) and small light trucks (LDT1s) and a second set 

of declining standards that would apply to heavier light trucks (LDT2s, LDT3s. LDT4s), and MDPVs.

226 This preamble presents the proposed standards in terms of milligrams per mile for convenience. The 

associated regulatory language will continue to present the standard in terms of grams per mile for 

consistency with earlier programs. 
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values from the selected bins met the fleet average standard for that model year. Table 

IV-1 presents the per-vehicle bin standards.

Similarly, the proposed fleet average NMOG+NOX standards measured over the 

SFTP are summarized in Table I-2. The proposed SFTP NMOG+NOX fleet average 

standards decline from MY 2017 until MY 2025. In this case, the same standards would 

apply to both lighter and heavier vehicles. In MY 2025, the SFTP NMOG+NOX standard 

would reach its fully phased-in fleet average level of 50 mg/mi.

We are also proposing PM standards as part of this Tier 3 program. The 

proposed PM standards would apply to each vehicle separately (i.e., not as a fleet 

average). Also, in contrast to the declining NMOG+NOX standards, the proposed 

certification PM standard on the FTP is 3 mg/mi for all vehicles and for all model years, 

but phasing in beginning in MY 2017 for vehicles at or below 6,000 lbs GVWR and in 

MY 2018 for vehicles above 6,000 lbs GVWR. Based on EPA and CARB test programs, 

most current light duty vehicles are already performing at or below this level. However, 

some vehicles are emitting above this level, due to such factors as combustion chamber 

designs, and fuel and oil consumption controls that are not optimized for low PM 

emissions. The intent of the proposed 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 proposed program also 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 described in more 

detail below. As presented in Table I-3, for vehicles at or below 6000 lbs GVWR, these 

FTP certification and in-use standards would be phased in beginning with a requirement 

that at least 20 percent of a company’s U.S. sales meet the standards in MY 2017 and 

reaching a 100 percent compliance requirement in MY 2021. The proposed standards 

represent a significant numerical reduction from the Tier 2 PM emission standards of 10 

mg/mi for light-duty vehicles.

Finally, the proposed Tier 3 program includes PM standards evaluated over the 

US06 cycle (a component of the SFTP test, discussed further below) at a level of 10 

mg/mi for vehicles at or below 6,000 lbs GVWR and 20 mg/mi for heavier vehicles. We 

are proposing separate standards for different sizes of vehicles because PM generation 

typically increases when vehicles are carrying heavier loads and/or when they are pulling 

trailers. The US06 PM standards would phase in on the same schedule as the FTP PM 

standards, reaching 100 percent of each company’s U.S. sales by MY 2022. These US06 

standards would apply to the same vehicle models that a manufacture chose to certify to 

the FTP PM standard during the percent phase in period. PM levels over the US06 are 

typically higher than the PM emitted over the FTP due to the increased load on the 

vehicle. As in the case of the FTP PM standards, the intent of the proposed standard is 

to bring the emission performance of all vehicles to that already being demonstrated by 

many vehicles in the current light-duty fleet. 
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As with the FTP PM standard, we propose a separate in-use US06 PM standard 

during the percent phase-in period of 15 and 25 mg/mi for vehicles of 6000 lbs GVWR 

and less, and for vehicles above 6,000 lbs GVWR, respectively. 

The next subsections describe in more detail the proposed standards, how they

would be implemented over time, and the technological approaches that we believe will 

be available to manufacturers in order to comply.

3. Proposed FTP Standards

As summarized above, we propose 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). 

a. FTP NMOG+NOX Standards

We propose that the Tier 3 NMOG and NOX standards, both of which are 

important to reduce ambient ozone concentrations, be expressed in terms of the sum of 

the two pollutants, or as NMOG+NOX in mg/mi.227 This approach contrasts with the Tier 

2 standards, which were expressed as separate NMOG and NOX standards. We believe 

that the combined standard is appropriate for this proposed program for several reasons. 

At the stringent proposed emission levels, combining NMOG and NOX would provide a 

small amount of compliance flexibility, while at the same time significantly reducing 

both NMOG and NOX emission levels. For example, the combined standard would allow 

a gasoline vehicle manufacturer to have slightly higher NMOG if it were offset by lower 

NOX, or allow a diesel vehicle manufacturer to have slightly higher NOX if offset by

lower NMOG. This approach still ensures major reductions in both pollutants compared 

to today’s levels. This is because the very stringent level of the fully phased-in proposed 

combined standard (30 mg/mi NMOG+NOX) means that even with a degree of allowed 

trading off of one pollutant for the other, the maximum emissions of either pollutant 

would need to be well below current levels. The standards of the California LEV III 

program would also be expressed as NMOG+NOX; aligning Tier 3 with LEV III in this 

respect would facilitate an important element of a national program.

We believe that a fully phased-in level for the proposed fleet-average standard of 

30 mg/mi is the most stringent level that we could reasonably propose in the context of 

our proposed 10-ppm average standard for gasoline sulfur. As discussed in the feasibility

Section IV.A.5 below, when necessary margins of compliance are considered, this 

proposed standard is very close to zero. We request comment on this level for the 

proposed standard, as well as the declining standards during the transition years (see 

Table IV-3 below). EPA is proposing compliance mechanisms for the new Tier 3 FTP 

standards that are the same in most respects as those of the Tier 2 program. Using the 

 

227 In the past, EPA has taken a similar combined-standard approach for heavy-duty highway engines and 

many categories of nonroad engines.
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Tier 2 approaches as much as possible would streamline the implementation of the 

program by maintaining most of the compliance processes that manufacturers are familiar 

with today. 

A key compliance mechanism adapted from the Tier 2 program is a “bin” 

structure for the proposed emission standards. For these purposes, a bin is a set of several 

standards that are intended to be complied with as a group. Thus each Tier 3 bin would 

have an NMOG+NOX standard and a PM standard, as well as CO and HCHO standards. 

A manufacturer choosing to certify a vehicle to a certain bin would need to meet each of 

that bin’s standards for the full useful life of the vehicle. In this approach, manufacturers 

could certify vehicles to any of the bins, but they would have to ensure that average 

NMOG+NOX of the bins to which all of its vehicles were certified met the fleet average 

standard specific to the vehicle category (i.e., LDV/LDT1 and LDT2/3/4/MDPVs) for 

that model year. That is, a manufacturer would comply by ensuring that the salesweighted average of the NMOG+NOX values of the bins to which each of its vehicle 

models was certified was lower than the fleet average standard that applied for that model 

year.

For each proposed bin, we are including CO and HCHO standards at levels 

intended to prevent new engine and emission control designs that would result in 

increases in today’s CO and HCHO emissions. The standards are based on the 

comparable current LEV II and Tier 2 bin standards for these pollutants. The current 

standards do not appear to be technology-forcing, and we believe that this would continue 

to be the case as Tier 3 technologies are developed.

The bin structure that we are proposing for light duty vehicles, light-duty trucks, 

and MDPVs standards is presented in Table IV-1.

Table IV-1 Proposed 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, we are 

proposing that the same standards apply to LDVs, LDTs, or MDPVs, regardless of the 

fuel they use. That is, vehicles certified to operate on any fuel (e.g., gasoline, diesel fuel, 

E85, CNG, LNG, hydrogen, and methanol) would all be subject to the same standards. 
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We propose to maintain the fleet-average approach of the Tier 2 standards. 

Unlike Tier 2, the proposed Tier 3 fleet-average standards would decline annually to a 

fully phased-in level of 30 mg/mi NMOG+NOX. (The Tier 2 program, after a period of 

transition, established a single fleet average standard for all model years.) Specifically, 

we are proposing NMOG+NOX standards as measured on the FTP that would reduce the 

combined fleet-average emissions gradually from MY 2017 through 2025, as shown in 

Table IV-2 below. Beginning in MY 2017, we propose separate fleet average standards 

for lighter and heavier vehicles that would both decline annually, converging in MY 

2025. These proposed declining average standards are identical to CARB’s LEV III 

standards.229

The declining fleet-average NMOG+NOX standard requirement would begin in 

2017 for light-duty vehicles and light-duty trucks with a GVWR up to and including 

6,000 lbs and in 2018 for all other light-duty vehicles and light-duty trucks (i.e., those 

with a GVWR greater than 6,000 lbs). The standards would apply to the heavier vehicles 

a year later to facilitate the transition to a 50-state program for all manufacturers. During 

this transition period, there would be two fleet-average NMOG+NOX standards for each 

model year, one for LDVs and LDT1s and a second fleet-average standard for all other 

LDTs (LDT2s, LDT3s, and LDT4s) and for MDPVs. We are proposing that the fleetaverage standards decline in a linear way from MY 2017 through MY 2025, at which 

point the two fleet-average standards would converge and stabilize for later model years 

at the same level, 30 mg/mi, as shown in Table IV-2. Note that these fleet average 

standards are for LDT2 and larger vehicles, and for LDVs and LDT1s that manufacturers 

certify to the 150,000 mile useful life value. Section IV.A.7.b discusses how the Clean 

Air Act defines the useful life values for certification purposes and how EPA proposes to 

also provide for certification to slightly lower emissions standards to a useful life value of 

120,000 miles, representing a level of stringency that is equivalent to that of the emission 

standards corresponding to the 150,000 mile useful life, for LDVs and LDT1s.

Table IV-2 Proposed 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 vehicles above 6,000 lbs GVWR, the fleet average standards would apply beginning in MY 2018.

 

229 See California Low-Emission Vehicles (LEV) & GHG 2012 regulations adopted by 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 November 19, 2012).
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b These proposed standards apply for a 150,000 mile useful life. Manufacturers could choose to certify all 

of their LDVs and LDV1s to a useful life of 120,000 miles. If any of these families are certified to the 

shorter useful life, a proportionally lower numerical fleet average standard would apply, calculated by 

multiplying the respective 150,000 mile standard by 0.85 and rounding to the nearest mg.

EPA is also proposing an alternative phase-in of the 30 mg/mi FTP NMOG+NOX 

standard that would be available if a manufacturer prefers a stable standard and four full 

years of lead time, as specified in the Clean Air Act for vehicles above 6,000 lbs GVWR. 

For MYs 2017 and 2018, a manufacturer would certify vehicles up to 6,000 lbs GVWR 

to the primary declining FTP fleet average standards, as in the primary program. Then, 

beginning in MY 2019, a stable fleet average standard of 30 mg/mi would apply to an 

increasing percentage of a manufacturer’s light-duty vehicles, light-duty trucks, and 

MDPVs, both up to and above 6,000 lbs GVWR. The percent phase-in would match the 

proposed PM percent phase-in schedule, as discussed below – specifically 40 percent of 

sales in MY 2019, 70 percent in MY 2020, and 100 percent in MY 2021 and later model 

years. A manufacturer choosing to certify any vehicle to this alternative phase-in would 

need to use this approach for all its models in MYs 2019 and later; certifying part of its 

fleet to the declining fleet average after MY 2018 would not be permitted, since the 

structures of the two approaches, including the early credits provisions of the 

NMOG+NOx fleet average program, would not be consistent. A manufacturer certifying 

to this alternative phase-in would also need to comply with the alternative SFTP 

NMOG+NOx phase-in and the alternative FTP PM and US06 PM phase-ins as described 

below. Vehicles covered by the alternative phase-in programs would be considered 

“final Tier 3” vehicles and thus would also comply with the Tier 3 certification fuel and 

full useful life provisions. EPA requests comment on this alternative phase-in approach 

as well as on the primary option above. 

b. FTP PM Standards

We also propose new FTP standards for PM emissions, as summarized in Table 

IV-3 below. For many years, EPA’s focus for mobile source PM was on diesel engine 

emissions. In recent years, the very effective controls on PM exhaust emissions that 

manufacturers have developed for heavy-duty diesel engines have been successfully 

applied to light-duty diesel engines as well. At the same time, attention to gasoline 

engine PM emissions has increased as research has demonstrated that the level of PM 

from gasoline light duty vehicles is more significant than had been previously thought.230

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

current-technology gasoline vehicles are fairly low, well below the Tier 2 PM standards. 

At the same time we see considerable variation in PM emissions among vehicle models 

not consistently associated with any specific engine or emission control technology

 

230 Nam, E.; Fulper, C.; Warila, J.; Somers, J.; Michaels, H.; Bauldauf, R.; Rykowski, R.; and Scarboro, C. 

Analysis of Particulate Matter Emissions from Light-Duty Gasoline Vehicles in Kansas City, EPA420-R08-010. Assessment and Standards Division Office of Transportation and Air Quality U.S. Environmental 

Protection Agency Ann Arbor, MI, April 2008.
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(Section 1.5.1 of the draft RIA). As a result, we are proposing a new FTP PM standard 

that is set to ensure that all new vehicles would perform at a level representing what is 

already being achieved by well-designed Tier 2 emission control technologies. 

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, 

including a cold combustion chamber and fuel enrichment. During cold start, PM control 

via oxidation of semi-volatile organic compounds from the lubricating oil by catalytic 

converters is less effective. We believe that the proposed FTP PM standard can be 

achieved with improvements to the fuel controls during the cold start without the need for 

any new technology or hardware. Improvements in cold-start exhaust catalyst 

performance for NMOG+NOx control will also reduce emissions of semi-volatile organic 

PM. As such, cold start PM levels are relatively independent of vehicle application and 

therefore we are proposing a single FTP PM standard for all light-duty and MDPV 

vehicles. The PM standard level we are proposing would ensure that future PM 

performance is consistent with current well-performing Tier 2 vehicles. Unlike the 

NMOG+NOX FTP standard, the PM standard would not decline over time, since most 

manufacturers are already producing vehicles that would meet the proposed new 

standards. 

Although we believe it is important that the proposed FTP PM standard apply 

from the beginning of the Tier 3 program, we are proposing several provisions to provide 

a degree of flexibility for manufacturers in how many vehicle models would need to meet 

that standard in the early years of the program. Manufacturers have raised several issues 

that we believe these provisions would address. 

In meetings with EPA, several manufacturers have expressed concerns about how 

a PM standard in the range of the proposed 3 mg/mi standard would be implemented. 

One concern related to the initial uncertainties about PM emissions performance that will 

accompany the development of new engine technologies, including those that may be 

introduced to address the GHG emissions/fuel economy standards that EPA and NHTSA 

recently finalized for these vehicles. Also, manufacturers expressed concerns related to 

the testing of PM on the FTP, particularly about potential updates to the test procedures 

required to accurately measure PM at very low levels. Finally, related to the concerns 

about the new test procedures are the current limitations that exist for some 

manufacturers regarding the capacity of their test facilities to perform a significant 

volume of gasoline vehicle PM testing. 

For these reasons, we are proposing a percent-of-sales phase-in during the first 5 

years of the program to address these concerns. Beginning in MY 2017 (and in MY 2018 

for vehicles over 6,000 lbs GVWR), manufacturers would 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 would need to comply would increase each 

year, reaching 100 percent in MY 2021. In addition to this percent phase-in, we are 

proposing a separate PM standard of 6 mg/mi that would apply only for in-use testing of 

vehicles certified to the new standards, and only during the percent phase-in period. 
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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 would 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 would likely choose a single large-volume 

durability group to meet the 2017 requirements, we seek comment on an option to 

comply with the MY 2017 PM requirements by allowing manufactures to certify 10 

percent of all their light-duty vehicle sales in MY 2017 to the new PM standards, 

including light-duty vehicles over 6,000 lbs GVWR and MDPVs. This approach would 

be consistent with the CARB LEVIII program, which requires that 10 percent of all lightduty 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 proposing to limit the number of tests using the 

new procedures that a manufacturer would need to perform at certification and during inuse testing. Specifically, manufacturers would be required to test vehicles 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).231 Manufacturers could select which 

durability groups to test, but would 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 could limit their testing to 50 percent of their lowand high-mileage test vehicles. Again, manufacturers would need to rotate their vehicle 

models so that each model would be tested every other year. Overall, we believe that the 

flexibility that these proposed provisions would provide would facilitate the expeditious 

implementation of the proposed program, with no significant impact on the potential 

benefits of the program.

The PM standards that we are proposing are the most stringent technically

feasible standards within the implementation timeframe of this proposal. Although the 

CARB LEV III program includes a 1 mg/mi standard which will begin phasing in starting 

in MY 2025, they acknowledge that there is a need for continuing PM measurement 

method development prior to implementing this standard.232 In order for EPA to propose 

a standard at this level, there must be established methods to reliably and consistently

measure PM below that standard, for compliance purposes.

We request comment on all of the proposed FTP standards, their structure, and 

their implementation schedules.

 

231 Durability groups are a subset of engine families. Several engine families may have the same durability 

group.

232 California Air Resources Board (CARB) Initial Statement of Reasons, Public Hearing to Consider LEV 

III, , December 7, 2011
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Table IV-3 Summary of Proposed FTP Standards

Program Element Units

Model Year Notes

2017a2018 2019 2020 2021 2022 2023

NMOG+NOX

Standard

(fleet average)

mg/mi Per declining fleet average for cars and trucks (see Table IV-2)

b

PM Standards

Phase-in % 20 20 40 70 100 100 100

FTP

Certification mg/mi 3 3 3 3 3 3 3 Note c

In-use mg/mi 6 6 6 6 6 3 3 Note d

a

For vehicles above 6,000 lbs GVWR, the proposed FTP PM would apply beginning in MY 2018.

b The percent phase-in would not apply to the declining fleet average standards. 

c Manufacturers would be required to test 25 percent of each model year’s durability groups, minimum of 2.

d Manufacturers would be required to test 50 percent of their low and high mileage in-use vehicles.

As with the proposed FTP NMOG+NOX standards, EPA is also proposing an 

alternative phase-in of the 3 mg/mi FTP PM standard that would be available if a 

manufacturer prefers 4 full years of lead time for vehicles above 6,000 lbs GVWR. A 

manufacturer that chooses the alternative phase-in for the FTP NMOG+NOX program 

above could also postpone the beginning of the phase-in for PM compliance for vehicles 

above 6,000 lbs GVWR until MY 2019. For MYs 2017 and 2018, a manufacturer would 

certify vehicles up to 6,000 lbs GVWR to the 3 mg/mi FTP PM standard (and have a 6 

mg/mi in-use PM standard) for 20 percent of its sales in each of those years, as with the 

primary PM percent phase-in schedule. Then, for MYs 2019 and later, it would comply

with the 3 mg/mi (and 6 mg/mi in-use) PM standards for their LDVs, LDTs, and MDPVs, 

both up to and above 6,000 lbs GVWR. For MYs 2019 and 2020 (i.e., before the phasein is fully implemented in MY 2021), manufacturers choosing this alternative would be 

required to meet the PM standard on the same segment of their fleet vehicles being used 

to meet the NMOG+ NOX fleet average standard, and at the applicable phase-in 

percentage of sales for the given model year. Manufacturers certifying to the alternative 

PM phase-in standard would also need to comply with the alternative US06 PM phase-in 

as described below, as well as the NMOG+ NOX FTP and SFTP phase-ins. EPA requests 

comment on this alternative phase-in approach as well as on the primary PM phase-in 

option above. 

4. Proposed SFTP Standards 

In addition to the proposed FTP standards, we are proposing NMOG+NOX and 

PM standards as measured on the SFTP. The SFTP (and specifically the US06 

component of the test) is designed to simulate higher speeds and higher acceleration rates 

(and thus higher loads) when substantially more heat can be generated during the 
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combustion process. It is during these kinds of operation that engines can go into a fuel 

“enrichment” mode, where 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. To reduce emissions caused by excessive enrichment, we are proposing new 

SFTP standards. Further, as described in Section IV.A.4.c below, we are proposing 

limitations on the magnitude of enrichment that could be commanded by the vehicle 

operator. We describe the proposed SFTP standards in the following paragraphs. 

We are also proposing an SFTP composite CO standard of 4.2 g/mi for all model 

years 2017 (or 2018) 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 have reviewed certification and in-use NMOG and NOX data on a wide range 

of recent vehicles as tested on the US06 cycle. See Chapter 1 of the draft RIA for an 

analysis of this data. It is clear that most current vehicles are generally avoiding 

significant enrichment events during high-load operation and thus achieve relatively low 

NMOG+NOX emissions on the US06 test. The data shows that with minor (if any) 

improvements to engine calibrations and with no significant loss of performance, 

manufacturers are able to essentially eliminate enrichment events and their emissions 

consequences. Thus, as presented in Table IV-5 below, we are proposing new composite 

SFTP standards for NMOG+NOX at levels that would be more stringent than those 

required by the existing Tier 2 program. We believe that the new standards would 

require emission performance at levels currently achieved today by most vehicles under 

high-load operation, and we do not believe that significant additional reductions would 

result from SFTP standards more stringent than the proposed 50 mg/mi fully phased-in

level. The SFTP emissions value for certification of gaseous pollutants would 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. 

We believe that the proposed standards could be more challenging in the early

years of the program. Thus, we propose a declining fleet average standard that would 

become increasingly stringent from MY 2017 to MY 2025. Manufacturers would 

comply with a declining NMOG+NOX fleet-average SFTP standard for each year 

beginning in MY 2017 (MY 2018 for vehicles over 6000 lbs GVWR) and culminating for 

MY 2025 and later with a fleet-average standard of 50 mg/mi. 

To provide flexibility in meeting the fleet-average standards, manufacturers 

would determine for themselves what the specific SFTP composite standard would be for 

an individual vehicle family and report that self-selected standard and the measured 
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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 would choose any composite NMOG+NOX standard, up 

to 180 mg/mi, in even 10 mg/mi increments. The manufacturer would 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 proposed declining fleet-average SFTP NMOG+NOX

standards.

As with the proposed FTP NMOG+ NOX and PM standards, EPA is also 

proposing an alternative phase-in of the 50 mg/mi SFTP NMOG+ NOX standard that 

would be available if a manufacturer prefers a stable standard and four full years of lead 

time for vehicles above 6,000 lbs GVWR. For MYs 2017 and 2018, a manufacturer 

would certify vehicles up to 6,000 lbs GVWR to the primary SFTP declining fleet 

average standards, as in the primary program. Then, beginning in MY 2019, a stable 

fleet average standard of 50 mg/mi would apply to an increasing percentage of a 

manufacturer’s light-duty vehicles, light-duty trucks, and MDPVs, both up to and above 

6,000 lbs GVWR. The percent phase-in would match the proposed PM percent phase-in 

schedule, as discussed below. A manufacturer certifying to this alternative phase-in 

would also need to comply with the alternative FTP NMOG+ NOX phase-in and the 

alternative FTP PM and US06 PM phase-ins, as described elsewhere in this section. EPA 

requests comment on this alternative phase-in approach as well as on the primary option 

above. 

b. US06 PM Standards

Our proposed approach to addressing PM emissions on the US06 test (a 

component of the composite SFTP standard) is somewhat different from the SFTP 

standards that we are proposing for NMOG and NOX emissions. In the case of PM, 

US06 data on recent vehicles shows that current gasoline vehicles can have very low PM 

emissions, but US06 PM emission levels vary depending on many factors. In some 

cases, manufacturer emission control strategies that are sensitive to variations in 

operating conditions (e.g., variation due to driver behavior or automatic transmission shift 

points) appear to result in very low PM levels during some tests and yet higher PM on 

other tests on the same vehicle when driven slightly differently. We also believe that 

some of the observed high PM emissions may be partly due to increasing oil consumption 

in vehicles as they age, especially under higher-load conditions or hard closed-throttle 

deceleration conditions. Thus, we now believe that more focus on vehicles as they age is 

important. 

We have designed the proposed US06 PM standards in light of all of these 

factors, which relate to PM emission formation under relatively extreme driving 

conditions. For these standards, we are proposing to focus on the US06 cycle component 

of the composite SFTP, since most of our concern about PM formation and sensitivity of 

engine controls arises from high-speed, high-load driving conditions. Similarly, the 

quantity of PM emissions from warmed-up engines is closely related to engine load, since 

the higher rate of fuel consumption results in more opportunities for PM to form. For this 
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reason, we propose that heavier vehicles, which face high-load conditions more 

frequently than lighter vehicles, comply with a higher US06 standard and lighter vehicles 

comply with a lower standard. The proposed US06 PM standard would be 10 mg/mi for 

vehicles at or below 6,000 lbs GVWR and 20 mg/mi for heavier vehicles. 

EPA is seeking comment on the use of vehicle weight to establish separate US06 

PM standards for cars and trucks. The data presented in Chapter 1 of the draft RIA 

demonstrate that today’s heavier vehicles are already achieving PM emission levels well 

below our proposed 20 mg/mi standard and are approximately equivalent to the 

performance of lighter vehicles. According to our data, manufacturers appear to be 

controlling PM emissions in heavier vehicles over severe duty cycles. Thus, EPA seeks 

comment on the proposed US06 PM standards in general, including whether EPA should 

adopt a common US06 standard of 10 mg/mi or other level between 10 mg/mi and 20 

mg/mi for all light-duty vehicles.

As is the case for the proposed FTP PM standards, we are proposing a single pervehicle maximum standard to apply in each model year, with an allowable percentage 

phase-in schedule identical to the FTP PM phase-in. 

Finally, as with the FTP PM standard (and for the same reasons), we propose a 

slightly less stringent in-use US06 PM standard that would apply during the percent 

phase-in period only. The proposed in-use SFTP PM standards would be 15 mg/mi for 

vehicles at or below 6,000 lbs GVWR and 25 mg/mi for heavier vehicles. 

As with the proposed FTP and SFTP NMOG+ NOX standards and FTP PM 

standards, EPA is also proposing an alternative phase-in of the 20 mg/mi PM standard as 

measured on the US06 cycle, that would be available if a manufacturer prefers 4 full 

years of lead time for vehicles above 6,000 lbs GVWR. A manufacturer that chooses the 

alternative phase-in for the FTP NMOG+ NOX program above could also postpone the 

beginning of the phase-in for US06 PM compliance for vehicles above 6,000 lbs GVWR 

until MY 2019. For MYs 2017 and 2018, a manufacturer would certify vehicles up to 

6,000 lbs GVWR to the 10 mg/mi FTP PM standard (and have a 15 mg/mi in-use

standard) for 20 percent of its sales in each of those years, as with the primary PM 

percent phase-in schedule. Then, for MYs 2019 and later, it would comply with the 

respective standards for vehicles up to and above 6,000 lbs GVWR for their LDVs, 

LDTs, and MDPVs (i.e., 10 mg/mi and 15 mg/mi (in-use) for vehicles up to 6,000 lbs 

GVWR, and 20 mg/mi and 25 mg/mi (in-use) for vehicles above 6,000 lbs GVWR.) For 

MYs 2019 and 2020, manufacturers choosing this alternative would be required to meet 

both the FTP PM and the US06 PM standards on the same segment of their fleet vehicles 

being used to meet the 30 mg/mi fleet average NMOG+ NOX standards, at the applicable 

percent phase-in requirement for the given model year. Manufacturers certifying to the 

alternative US06 PM phase-in standard would also need to comply with the alternative 

FTP PM phase-in as described above, as well as the NMOG+ NOX FTP and SFTP phaseins. EPA requests comment on this alternative phase-in approach as well as on the 

primary US06 phase-in option above.
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All of the proposed SFTP/US06 standards are shown in Table IV-4 and Table 

IV-5. 

Table IV-4 Proposed LD and MDPV SFTP Composite Fleet Average Standards

Model Year

2017 2018 2019 2020 2021 2022 2023 2024 2025 and 

later

NMOG + NOX

(mg/mi)

103a97 90 83 77 70 63 57 50

CO (g/mi) 4.2 a

a

For vehicles above 6,000 lbs GVWR, the NMOG+NOX and CO standards would apply beginning in MY 

2018.

Table IV-5 Summary of Proposed SFTP Standards

Program Element Units

Model Year Notes

2017a2018 2019 2020 2021 2022 2023

NMOG+NOX Standard

(fleet average)

mg/mi Per declining fleet average for cars and trucks (see Table 

IV-4)

b

PM Standards

Phase-in % 20 20 40 70 100 100 100

US06

LDV, LDT1&2

Certification

mg/mi 10 10 10 10 10 10 10 Note 

c

LDV, LDT1&2

In-use

mg/mi 15 15 15 15 15 10 10 Note 

d

US06

LDT3&4, MDPV

Certification

mg/mi 20 20 20 20 20 20 20 Note 

c

LDT3&4, MDPV

In-use

mg/mi 25 25 25 25 25 20 20 Note 

d

a For vehicles above 6,000 lbs GVWR, the standards would apply beginning in MY 2018.

b The percent phase-in would not apply to the declining fleet average standards. 

c Manufacturers would be required to test 25 percent of each model year’s durability groups, minimum of 2.

d Manufacturers would be required to test 50 percent of their low and high mileage in-use vehicles.

We request comment on our proposed SFTP NMOG+NOX and PM standards, 

their structure, and their implementation schedules. 
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c. Enrichment Limitation for Spark-Ignition Engines

To prevent emissions from excessive enrichment during operating conditions 

represented by the SFTP cycles, we are proposing limitations on the magnitude of 

enrichment that could be commanded, including enrichment episodes encountered during 

in-use operation. During conditions where enrichment was demonstrated to be present on 

the SFTP, the nominal air to fuel ratio could not 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 would 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 would 

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. Manufacturers may

request approval of an alternative LBT definition for a unique technology or control 

strategy. The Agency could determine that an enrichment amount was excessive or not 

necessary and therefore deem that the approach did not meet the air to fuel ratio 

requirements. 

Enrichment required for thermal protection would continue to be allowed upon 

demonstration of necessity to the Agency, based upon temperature limitations of the 

engine or exhaust components. Manufacturers would 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.

5. Feasibility of the Proposed NMOG+NOX and PM Standards

In this section, with additional support in Chapter 1 of the draft RIA, we describe 

how we reached our conclusion that the proposed Tier 3 standards would be 

technologically feasible in the time frame of the program. For each of the proposed 

emission standards, the lead time provided by the proposed 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 proposed 

rulemaking. For example, many of the technologies that manufacturers will begin to 

develop 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 proposed national program. Similarly, manufacturers are already 
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building some vehicles that comply with our proposed evaporative emissions standards in 

response to the CARB LEV III evaporative standards. In addition, as described above, 

our proposed program incorporates a number of phase-in provisions that would ease the 

transition to compliance, including time some manufacturers would need to install PM 

testing capability and to ramp up production on a national scale. We invite comment on 

our conclusions relating to the feasibility of the proposed program for each of the 

standards, as discussed below, including our overall conclusion that technological lead 

time is not a driving factor in complying with any of the proposed standards. 

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 proposed 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 proposed Tier 3 

NMOG+NOX and PM standards or similar levels. EPA has assessed the emissions 

control challenges manufacturers would 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 proposed Tier 3 program would 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 would be certified 

on gasoline with a fuel sulfur content of 10 ppm and operated on in-use gasoline with 10 

ppm sulfur or less.233 Therefore, our primary assessment does not incorporate the 

degradation of emission control system caused by higher levels of sulfur content, as is 

discussed in Section IV.6 below and in the draft RIA. This assessment reinforces the 

critical role of gasoline sulfur control, as proposed in Section V below, in making it 

possible for EPA to propose 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 vehicle emissions as well as our projections of how we expect 

that sulfur would affect compliance with standards in the range of the proposed Tier 3 

standards. 

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 would 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 

 

233 Our technology, feasibility, and cost assessments are also consistent with an assumption that 

certification fuel would contain 15 percent ethanol and would have other properties as specified in Section 

IV.D below.
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feasibility assessment must consider that different technologies may be needed on 

different types of vehicle applications (i.e., 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 proposed 

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 proposed program. We invite comment on our assessments of 

these or any other such potential interactions. Also, although we are not aware of any 

technological reasons that vehicle emission controls responding to new Tier 3 

requirements should affect vehicle CO2 emissions or fuel economy in any significant 

way, it is possible that such interactions could occur. For example, there may be some 

slight change of vehicle mass if manufacturers explore lighter exhaust manifold materials 

in order to reduce thermal mass and promote earlier catalyst light-off or increases in 

vehicle mass due to the addition of emissions control equipment such as hydrocarbon 

adsorbers. We invite comment on any such potential effects as well. 

a. FTP NMOG+NOX Standards

The proposed new emission requirements include stringent NMOG+ NOX

standards on the FTP that would require new vehicle hardware in order to achieve the 30 

mg/mi fleet average level in 2025. The type of new hardware that would be required 

would vary depending on the specific application and emission challenges. Smaller 

vehicles with corresponding smaller engines would generally need less new hardware 

while larger vehicles may need additional hardware and improvements beyond what 

would be needed for the smaller vehicles. While some vehicles, especially larger light 

trucks, may face higher costs in meeting the proposed standards, it is important to 

remember that not every vehicle needs to meet the standard. The proposed 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 standard. We believe that the availability of the proposed less-stringent bins 

would allow for feasible and cost-effective compliance 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 proposed 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. 
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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 would face in 

meeting the lower fleet average emission standards. Each of these considerations is 

described in greater detail below.

The current federal fleet is certified to an average of Tier 2 Bin 5, equivalent to 

160 mg/mi NMOG+NOX.

234

 For MY 2009, 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 was not an unexpected result as there is currently no motivation for vehicle 

manufacturers to produce a federal fleet that over-complies with respect to the current 

Tier 2 standards. By comparison, in the California fleet, where compliance with the 

“PZEV” program encourages 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 Tier 2 Bin 3. 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 Tier 2 Bin 3. In many cases identical vehicles are being 

certified to a lower standard in California and a higher standard federally. 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 

performance in-use. Based on these patterns of federal and California certification, EPA 

believes that much of the existing Tier 2 fleet could 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.)

 

234 The current 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.
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 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, 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 would design for in order to 

comply with the proposed 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) would need 

improvements sufficient to reach about 15 mg/mi (50 percent of a 30 mg/mi standards). 

To understand how the several currently-used technologies described below could 

be used by manufacturers to reach the stringent proposed Tier 3 NMOG+NOX standards, 

it is helpful to consider emissions formation in common modes of operation for gasoline 

engines, or modal analysis.235 The primary challenge faced by manufacturers for 

producing Tier 3 compliant light-duty gasoline vehicle powertrains would be to reduce 

the emissions during cold-start operation which, based on modal analysis of a gasoline 

powered vehicle being operated on the FTP cycle, occurs during about the first 50 

seconds after engine start. Thus, effective control of these cold-start emissions would be 

the primary technological goal of manufacturers complying with the proposed Tier 3 FTP 

standards. 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. 

b. SFTP NMOG+NOX Standards

The increase in the stringency of the SFTP NMOG+NOX standards, specifically

across the US06 cycle, would 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 

 

235 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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control hardware to tolerate higher combustion and exhaust temperatures expected in 

these future GHG-oriented engine designs. The upgraded materials or components would 

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, changes to the fuel/air mixture by increasing the fuel 

fraction has historically been the primary method available to manufacturers to protect 

the catalyst and other exhaust components from over-temperature conditions. Changing 

the fuel/air mixture 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 

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 proposed 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 2017 and later vehicles would be able to comply with 

the proposed SFTP standards, directly, or through the flexibility of the averaging, 

banking and trading program. For further information on the analysis see Chapter 1 of 

the draft 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 would generally also only require 

additional focus on fuel control of the engines and diligent implementation of new 
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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 would be 

capable of continuing to perform optimally even as the systems age. 

We based our conclusions about the ability of manufacturers to meet the proposed 

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 

light-duty vehicles demonstrate that the majority of vehicles are currently achieving 

levels at or below the proposed Tier 3 FTP standards. 

The testing results can be found in Chapter 1 of the draft RIA. A small number of 

vehicles are at or just over the proposed 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 

would also provide the necessary PM control. Vehicles that currently have higher PM 

emissions over the FTP or SFTP at higher mileages would likely be required to control 

oil consumption and combustion chamber deposits. 

We also analyzed PM test data on US06 emissions for current Tier 2 vehicles. 

The data show that many vehicles are already at or below the proposed standards on the

US06. Vehicles that have high PM emission rates on the US06 would 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 would 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. 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 proposed standards would address the emissions control system’s ability to 
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control emission during cold start. The effectiveness of current vehicle emissions 

control systems 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 would 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, 

thermal management, close-coupled catalysts, catalyst platinum group metals (PGM) 

loading and strategy, 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 

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.
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 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 are 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 draft RIA. 

Discussions between EPA, CARB, vehicle manufacturers, and major component 

suppliers indicated that large light-duty trucks (e.g., pickups and full-size sport utility

vehicles (SUVs) in the LDT3 and LDT4 categories) would be the most challenging lightduty vehicles to bring into compliance with the proposed Tier 3 NMOG+NOX standards 

at the 30 mg/mi corporate average emissions level. A similar challenge was 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 (m

g/mi)@ 120,0

0

0

miles

NMOG+NOx Emissons of Tier 3 LD3/T4

NMOG+NOx Emissions of Tier 2 Bin 5 LDT3/4 

60% 

Compliance

Margin

50% Compliance Margin

Tier 2 Bin 5 NMOG+NOx Standard

Tier 3 NMOG+NOx Standard

Hydrocarbon Adsorber

Reduced Thermal Mass 

+ Calibration Changes

Increased Catalyst 

Active Materials + 

Calibration Changes

Secondary 

Air Injection

+ Calibration Changes

77% Emissions 

Reduction

Figure IV-1: Contribution of Tier 3 Technologies to Large Light-Duty Truck 

Compliance236

 
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6. Impact of Gasoline Sulfur Control on the Feasibility of the Proposed Vehicle 

Emission Standards

a. Fuel 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 

nitrogen oxides when air-to-fuel ratio control operates in a condition of relatively low 

amplitude/high frequency oscillation about the stoichiometric point. Sulfur is a wellknown catalyst poison. There is a large body of work demonstrating sulfur inhibition of 

the emissions control performance of PGM three-way exhaust catalyst 

systems.237,238,239,240,241,242,243,244,245,246 The nature of sulfur interactions with washcoat 

materials, active catalytic materials and catalyst substrates is complex and varies with 

catalyst composition and 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 

 

236 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.

237 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.

238 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.

239 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.

240 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.

241 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.

242 Takei, Y., Kungasa, Y., Okada, M., Tanaka, T. Fujimoto, Y. (2000). Fuel Property Requirement for 

Advanced Technology Engines. SAE Technical Paper 2000-01-2019.

243 Takei, Y., Kungasa, Y., Okada, M., Tanaka, T. Fujimoto, Y. (2001). “Fuel properties for advanced 

engines.” Automotive Engineering International 109 12, 117-120.

244 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.

245 Shen, Y., Shuai, S., Wang, J. Xiao, J. (2008). Effects of Gasoline Fuel Properties on Engine 

Performance. SAE Technical Paper 2008-01-0628.

246 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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Page 107 of 995

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 alumina 

washcoatings (see Figure IV-2).247 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. 

 

247 Heck, R.M., Farrauto, R.J. (2002). Chapter 5: Catalyst Deactivation in Catalytic Air Pollution Control, 

2

nd Edition. John Wiley and Sons, Inc.
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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 2002.247
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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.248,249,250,251 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.252 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).253,254 Pd is also of increased importance for meeting 

Tier 3 standards due to its unique application in the closed-coupled-catalysts location 

required for vehicles certifying to very stringent emission standards. Pd is required in 

closed-coupled catalysts due to its resistance to high temperature thermal sintering. 

Sulfur removal from Pd requires rich operation at higher temperatures than required for 

sulfur removal from other PGM catalysts. 255

In addition to its interaction with catalyst materials, sulfur can also react with the 

washcoating itself to form alumina sulfate, which in turn can block coating pores and 

reduce gaseous diffusion to active materials below the coating surface.256 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 when 

high-load, high-temperature conditions are encountered.257

 

248 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.

249 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.

250 Heck, R.M., Farrauto, R.J. (2002). Chapter 6: Automotive Catalyst in Catalytic Air Pollution Control, 

2

nd Edition. John Wiley and Sons, Inc.

251 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.

252 Heck, R.M., Farrauto, R.J. (2002). Chapter 6: Automotive Catalyst in Catalytic Air Pollution Control, 

2

nd Edition. John Wiley and Sons, Inc.

253 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.

254 Ball, D., Clark, D., Moser, D. (2011). Effects of Fuel Sulfur on FTP NOX Emissions from a PZEV 4 

Cylinder Application. SAE Technical Paper No. 2011-01-0300.

255 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.

256 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.

257 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. 
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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. However, 

it cannot completely eliminate the effects of sulfur poisoning. 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 fuel sulfur levels will bring emission benefits unachievable by catalyst regeneration 

procedures alone.258 Furthermore, regular operation at these temperatures and at rich airto-fuel ratios is not desirable, for several reasons. 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. Additionally, it is not always possible to maintain these catalyst 

temperatures (because of cold weather, idle conditions, light load operation) and the rich 

air-to-fuel ratios necessary can result in increased PM, NMOG and CO emissions. 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. 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 (in terms of percent conversion efficiency) 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 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.259 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.

In 2005, EPA and several automakers jointly conducted a program that examined 

the effects of sulfur and other gasoline properties, benzene, and volatility on emissions 

from a fleet of nine Tier 2 compliant vehicles. Section 1.2.3 of the draft RIA provides 

details of the Mobile Source Air Toxics (MSAT) Study.

260

 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.261 In particular, the study found a nearly 50 

percent increase in NOX over the FTP when sulfur was increased from 6 ppm to 32 ppm. 

Given the prep procedures related to catalyst clean-out and loading used by these studies, 

 

258 See Chapter 1 of the RIA (Section 1.2.3.2) for more details on this study and its results.

259 Tier 2 Regulatory Impact Analysis (EPA 420-R-99-023, December 22, 1999), available at 

http://epa.gov/tier2/finalrule.htm#regs.

260 This test program is described in Chapter 6 of the RIA of the MSAT2 final rulemaking, EPA 420-R-07-

002, February 2007, available athttp://www.epa.gov/otaq/regs/toxics/420r07002chp6.pdf.

261 See Chapter 6 of the Regulatory Impact Analysis for the Control of Hazardous Air Pollutants from 

Mobile Sources Final Rule, EPA 420-R-07-002.
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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 

sulfur loading was reversible for Tier 2 vehicles, and that there were likely to be 

significant emission reductions possible with further reductions in gasoline sulfur level. 

For more discussion of the impact of gasoline fuel sulfur on the current light-duty vehicle 

fleet, see Section III.A. 

b. EPA Gasoline Sulfur Effects Testing

Both the MSAT and Umicore studies showed the emission reduction potential of 

lower sulfur fuel on Tier 2 and later technology vehicles over the FTP cycle. 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 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. 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 81 cars and light trucks 

recruited from owners in southeast Michigan, covering model years 2007-9 with 

approximately 20,000-40,000 odometer miles. 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. A nominal 

concentration of approximately 25 ppm was targeted for the high level to be 

representative of retail fuel available to the public in the vehicle recruiting area. 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, suggesting that reversible sulfur loading exists in the 

in-use fleet and has a measurable effect on aftertreatment performance (Table IV-6). For 

example, Bag 2 NOX emissions dropped 32 percent between the pre- and post-cleanout 

tests on 28 ppm fuel. 

Table IV-6 Average Clean-out Effect on In-use Emissions 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 – – 4.7% 

(0.0737)

– – 15.4%

(< 0.0001)
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Bag 2 31.9% 

(0.0009)

16.5% 

(0.0024)

– 17.8% 

(0.0181)

15.3% 

(0.0015)

–

Bag 3 38.3% 

(<0.0001)

21.4% 

(<0.0001)

19.5%

(0.0011)

27.8% 

(<0.0001)

12.0% 

(<0.0001)

24.5% 

(<0.0001)

FTP Composite 11.4% 

(<0.0001)

4.1% 

(0.0187)

7.6% 

(0.0008)

3.0% 

(0.0751)

6.9% 

(0.0003)

13.7% 

(<0.0001)

Bag 1 – Bag 3 – – 4.2%

(0.0714)

– – –

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 differences in 

the effectiveness of the clean-out procedure when done using 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 47 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. 

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 5.9%

(0.0896)

5.4%

(0.0118)

7.3%

(0.0023)

4.6%

(0.0465)

11.1%

(<0.0001)

–

Bag 2 47.3%

(0.0010)

40.2%

(<0.0001)

–

a

34.4%

(0.0041)

53.6%

(<0.0001)

–

Bag 3 51.2%

(<0.0001)

35.0%

(<0.0001)

10.1%

(0.0988)

45.0%

(<0.0001)

25.4%

(<0.0001)

–

FTP 

Composite

17.7%

(0.0001)

11.2%

(<0.0001)

8.3%

(0.0003)

8.8%

(0.0003)

21.4%

(<0.0001)

–

Bag 1 – Bag 3 –

a

–

a

5.8%

(0.0412)

–

a

–

a

–

a

Sulfur level not significant at α = 0.10. 

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 

59 percent between 28 ppm and 5 ppm overall. For some pollutants, such as Bag 2 NOX, 
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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. Other results, 

such as Bag 1 hydrocarbons, did show a significant miles-by-sulfur interaction. In this 

case, determination of a sulfur level effect for the in-use fleet required estimation of a 

miles-equivalent level of sulfur loading, which was determined by the cleanout results 

obtained from the baseline testing on the vehicles as-received. 

Table IV-8 Summary of Mixed Model Results for Emission Reductions When Going 

from 28 ppm to 5 ppm Sulfur Gasoline, Adjusted for In-use Sulfur Loading 

(Mileage Accumulation) Where Appropriate 

NOX

(p-value)

THC

(p-value)

CO

(p-value)

NMHC

(p-value)

CH4

(p-value)

NOX+NMOG

(p-value) PMa

Bag 1 10.7%

(0.0033)

8.5%b

(0.0382)

7.5%b

(0.0552)

7.5%

(< 0.0001)

13.9%b

(< 0.0001) N/A –

Bag 2 59.2%

(< 0.0001)

48.8%

(< 0.0001) –

a 44.8%b

(0.0260)

49.9%

(< 0.0001) N/A –

Bag 3 62.1%

(< 0.0001)

40.2%

(< 0.0001)

20.1%

(< 0.0001)

49.9%

(< 0.0001)

29.2%

(< 0.0001) N/A –

FTP Composite 23.0%b

(0.0180)

13.0%b

(0.0027)

11.9%b

(0.0378)

10.6%b

(0.0032)

25.8%b

(< 0.0001)

17.3%

(0.0140) –

Bag 1 – Bag 3 –

a 5.2%

(0.0063)

4.3%

(0.0689)

5.1%

(0.0107)

4.6%

(0.0514) N/A –

a

Sulfur level not significant at α = 0.10. For THC Bag 1 and CH4 Bag 1, because the effect of clean-out 

was not statistically significant, the reduction estimates are based on the estimates of least squares means.

b Model with significant sulfur and mileage interaction term. 

Major findings from this study include:

 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 

proposed gasoline sulfur standards would be expected to achieve significant 

reductions in emissions of NOX, hydrocarbons, and other pollutants of interest 

in the in-use fleet.

The overall reductions found in this study are in agreement with other low sulfur 

studies conducted on Tier 2 vehicles. The magnitude of NOX and HC reductions found in 

this study when switching from 28 ppm to 5 ppm fuel are consistent with those found in 
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Page 114 of 995

MSAT and Umicore studies mentioned above. For further details regarding the Tier 2 InUse Gasoline Sulfur Effects Study, see the draft report on this work.262

Fuel Sulfur Impacts on Vehicles at the Proposed Tier 3 Levels

As discussed in previous sections, the Tier 3 Program would reduce fleet average 

NMOG+NOX emissions by over 80 percent. The feasibility of the proposed 30 mg/mi 

NMOG+NOX fleet average standard depends on a degree of emissions control from 

exhaust catalyst systems that will require gasoline at 10 ppm sulfur or lower. The most 

likely control strategies would involve using exhaust catalyst technologies and powertrain 

calibration primarily focused on reducing cold-start emissions of NMOG and on 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, would be to reduce NOX emissions to near-zero levels. This 

would allow sufficient NMOG compliance margin to allow vehicles to meet the 

combined NMOG+NOX emissions standards for their full useful life.

Achieving the proposed Tier 3 emission standards would 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 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.263

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 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 gasoline up to the Tier 2 80 ppm 

gasoline sulfur cap. 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 operation on gasoline 

 

262U.S. EPA. 2013. "The Effects of Fuel Sulfur Level on Emissions from Tier 2 Vehicles In-Use." EPA420-D-13-003. Available in the docket for this rule. 

263 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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Page 115 of 995

with an average of 10 ppm sulfur and a maximum cap of 30 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. 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 highersulfur gasoline.

Emissions of vehicles certified to the SULEV standard of the California LEV II 

program, or the equivalent Tier 2 Bin 2 standards, can provide some insight into the 

impact of fuel sulfur on vehicles at the very low proposed Tier 3 emissions levels. 

Vehicle testing by Toyota 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. Testing of a SULEV-certified PZEV vehicle by Umicore showed a pronounced, 

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.264 The PZEV Chevrolet Malibu, after being aged to an equivalent of 

150,000 miles, demonstrated emissions at a level equivalent to the compliance margin for 

the Tier 3 Bin 30 NMOG+NOX standard 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 

proposed Tier 3 30 mg/mi NMOG+NOX standard.265 This represents a NOX percentage 

increase that is approximately 2-3 times of what has been reported for similar changes in 

fuel sulfur level for Tier 2 and older vehicles over a similar difference in fuel sulfur.266,267 

There are no LDTs larger than LDT2 and no larger non-hybrid LDVs. We expect that 

additional catalyst technologies, for example increasing catalyst surface area (volume or 

substrate cell density) and/or increased PGM loading, would need to be applied to larger 

vehicles in order to achieve the catalyst efficiencies necessary to comply with the 

proposed Tier 3 standards. Any sulfur impact on catalyst efficiency would have a larger 

impact on vehicles and trucks that rely more on very high catalyst efficiencies in order to 

achieve very low emissions.

 

264 Heck, R.M., Farrauto, R.J. (2002). Chapter 6: Automotive Catalyst in Catalytic Air Pollution Control, 

2

nd Edition. John Wiley and Sons, Inc.

265 Ball, D., Clark, D., Moser, D. (2011). Effects of Fuel Sulfur on FTP NOX Emissions from a PZEV 4 

Cylinder Application. SAE Technial Paper No. 2011-01-0300.

266 Butler, A. and Choi, D. (2012). The Effects of Fuel Sulfur Level on Emissions In-Use Tier 2 Vehicles.

Found in the docket, EPA–HQ–OAR–2011–0135.

267 Shapiro, E. (2009). National Clean Gasoline – An Investigation of Costs and Benefits. Published by the 

Alliance of Automobile Manufacturers.
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Page 116 of 995

The negative impact of gasoline sulfur on catalytic activity and the resultant loss 

of exhaust catalyst effectiveness to chemically reduce NOX and oxidize NMOG and air 

toxic emissions occurs across all vehicle categories. However, the impact of gasoline 

sulfur on NOX emissions control of catalysts 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 levels, 

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 low enough to comply with the 30 mg/mi fleet-average standard. These 

vehicles represent a sufficiently large segment of light-duty vehicle sales now and in the 

foreseeable future that their emissions could not be offset (and thus the fleet-average 

standard achieved) by certifying vehicles to bins below the fleet average. Any

degradation in catalyst performance due to gasoline sulfur would reduce or eliminate the 

margin necessary to ensure in-use compliance with the proposed Tier 3 emissions 

standards. Certifying to a useful life of 150,000 miles versus the current 120,000 miles 

would further add to manufacturers’ compliance challenge for Tier 3 large light trucks 

(See Section IV.7.b below for more on the useful life requirements.) 

c. Gasoline Sulfur Control Required to Meet Tier 3 Emissions Standards

The impact of gasoline sulfur poisoning on exhaust catalyst performance and the 

relative stringency of the Tier 3 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.A.2, the proposed 10-ppm standard for 

sulfur in gasoline represents the lowest practical limit from a standpoint of fuel 

production, handling and transport. While lowering gasoline sulfur to levels below 10 

ppm would further help ensure in-use vehicle compliance with the Tier 3 standards, the 

Agency believes that a gasoline sulfur standard of 10 ppm would allow compliance by

gasoline-fueled engines with a national fleet average of 30 mg/mi NMOG+NOX. The 

level of the proposed Tier 3 standards was considered in light of a 10-ppm average sulfur 

level for gasoline. Not only should a 10-ppm sulfur standard enable vehicle 

manufacturers to certify their entire product line of vehicles to the Tier 3 fleet average 

standards, but based on the results of testing both Tier 2 vehicles and SULEV vehicles as 

discussed above, reducing gasoline sulfur to 10 ppm should enable these vehicles to 

maintain their emission performance in-use over their full useful life. It is important to 

note that while the preceding discussion focused on gasoline sulfur control, spark ignition 

engines operating on other fuels (i.e., CNG, LPG, E85) and utilizing a three way catalyst

systems for control of emission are similarly affected by the sulfur levels in the fuel. We 

invite comment on all aspects of our analysis of gasoline sulfur effects and our 

conclusions, especially comments that include any additional relevant testing data.
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7. Other Provisions

a. Early Credits

The California LEV III program is scheduled to begin at least two model years 

earlier than the proposed federal Tier 3 program.268 As stated earlier, EPA proposes to 

implement the Tier 3 standards 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 is meeting at that time. In addition, the 

California NMOG+NOX standards will continue to decline resulting in the gap growing 

between the current federal program and LEV III. The early credit program we are 

proposing is designed to accomplish three goals: (1) Encourage manufacturers to 

produce a cleaner federal fleet earlier than otherwise required; (2) provide needed 

flexibility to the manufacturers to facilitate the “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) create a Tier 3 program that 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. 

The first provision that we are proposing to address these goals is to allow 

manufacturers to generate early federal credits against the current Tier 2 Bin 5 

requirement269 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 would only be 

available for manufacturers complying under the primary program (declining fleet 

average), not the alternative phase-in approach (Section IV.A.3.a above). In order to 

generate these credits, manufacturers would sum the NMOG and NOX certification 

standards for each federally certified Tier 2 vehicle and calculate an NMOG+ NOX fleet 

average. Credits would be based on the difference between the new, cleaner, fleet 

average and the Tier 2 Bin 5 requirement (160 mg/mi total of NMOG and NOX). We 

expect that manufacturers could accomplish this by certifying existing Tier 2 vehicles to 

a lower fleet average, mainly for the higher bins as the current sulfur content in gasoline 

would preclude them from certifying the cleanest bins federally (Our analysis, presented 

in Section IV.A.5 above and Chapter 1 of the draft RIA, shows that many vehicles 

currently certified to Tier 2 Bin 5 could likely be certified to a lower bin with some 

reduction in compliance margin; e.g., from Bin 5 to Bin 4 or Bin 3.) We expect to realize 

early environmental benefits, as the result of a cleaner federal fleet, that justify the credits 

generated.

We believe that this provision would help us realize both our first and our second 

goals. For example, a manufacturer certifying their federal fleet to Tier 2 Bin 4 would 

earn 50 mg/mi of NMOG+ NOX credits per vehicle (i.e., 160 mg/mi minus 110 mg/mi) 

 

268 The LEV III program as approved by the California Air Resources Board, January 2012.

269 Tier 2 standards are not set in the form of NMOG+NOx. The equivalent Tier 2 Bin 5 fleet average in 

NMOG+ NOX terms would be equal to 160 mg/mi (90 mg/mi NMOG + 70 mg/mi NOX).
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which should encourage manufacturers to certify a cleaner federal fleet and provide 

ample opportunity for credit generation to facilitate the “step down” in stringency. 

However, if we allowed excessive early credits to be generated it could allow 

manufacturers to delay their federal compliance with the same fleet average as California 

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 are proposing that the application of the early federal credits be 

constrained under the following conditions:

 Early federal credits generated under the provision described above could be 

used without limitation in MY 2017.

 Credits used for compliance in MY 2018 and beyond would 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 multiplied by the ratio of 50-state 

sales to California only sales. Calculation of these credits would account for 

the fact that some LEV III credits may have begun to expire and would no 

longer be eligible as a basis for Tier 3 early credits.

By capping the available federal credits we believe that the two programs, LEV 

III and Tier 3 would be at parity starting in 2018 MY. In addition, because the number of 

federal early credits that could be used would be based on the number of LEV III credits 

that the manufacturer had generated, there may be additional motivation for 

manufacturers to over-perform in California during the initial model years.

We are proposing that early credit life be limited to 5 years with no discounting, 

consistent with the California LEV II and LEV III programs and similar to the basic 

credit carry-forward provisions of the recent light-duty and heavy-duty greenhouse gas 

rules. We are not proposing any carry-over of Tier 2 credits for use in the Tier 3 

program. We seek comment on the 5-year credit life in the context of the programs goals 

of harmonization with California LEV III and whether the added flexibility would be 

advantageous relative to any added burden associated with corresponding record 

retention requirements. 

b. 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.270 

For LDVs and LDTs (including MDPVs) under the Tier 2 program, there have 

historically been both “full useful life” values, approximating the average life of the 

vehicle on the road, and “intermediate useful life” values, representing about half of the 

 

270 The useful life of the vehicle should not be confused with the vehicle’s emissions warranty. The useful 

life value is relevant for certification and in-use compliance purposes; the emissions warranty relates to the 

period during which the manufacturer is obligated to repair or replace failing emission control equipment 

on a properly maintained vehicle.
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vehicle’s life. For the Tier 3 program, we are proposing several changes to the current 

useful life provisions that are appropriate to the proposed standards described above. 

Every vehicle manufacturer with which the EPA has met has expressed the desire 

for a single national vehicle fleet and has indicated an ability and willingness to certify

their vehicles to a 150,000 mile, 15 year full useful life in support of that goal, since the 

LEV III program would apply a single 150,000 mile, 15 year useful life value for all of 

the new standards. However, the CAA, written at a time when vehicles did not last as 

long as today, precludes EPA from requiring a useful life value longer than the 120,000 

mile (and 10 or 11 year, as applicable) value set in Tier 2, for all LDVs and for LDTs up 

to 3,750 lbs LVW and up to 6,000 lbs GVWR (LDT1s). For vehicles heavier than these 

limits (i.e., LDT2s, 3s, 4s, as well as MDPVs, representing a large fraction of the lightduty fleet) we are proposing a 150,000 mile, 15 year useful life value. For the lighter 

vehicles, we are proposing to continue to apply the 120,000 mile (and 10 or 11 year, as 

applicable) full useful life requirement from the Tier 2 program. Numerically, we are 

proposing 120,000 mile useful life NMOG+NOX standards that are 85 percent of the 

respective NMOG+ NOX 150,000 mile standards. (See Chapter 1 of the draft RIA for a 

description of our analysis of this relationship.) For the lighter vehicles, we propose that 

manufacturers be allowed to choose to certify to either useful life value in complying 

with the proposed fleet average and per-vehicle standards.271 A manufacturer choosing to 

comply with the 120,000 mile useful life standards for any of their lighter vehicles would 

demonstrate compliance with the numerically lower fleet-average NMOG+ NOX

standards for all LDV and LDT1 families. Standards for all other pollutants272 would 

remain the same regardless of whether compliance was at the 120,000 mile or the 

150,000 mile useful life periods. If a vehicle manufacturer chose to comply with the 

120,000 mile useful life standards for their lighter vehicles, it would be required to 

separately demonstrate that its larger vehicles complied with the 150,000 mile fleet 

average standards.

Except for vehicles not required to meet a 150,000 miles useful life and for which 

a manufacturer chose to apply the 120,000 mile useful life value, we propose that 

manufacturers be required to certify 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. This useful-life requirement would apply beginning in MY 2017. Beginning in 

MY 2020, all vehicles would need to certify to the 150,000 mile useful life, regardless of 

NMOG+NOX certification bin, unless they are allowed and the manufacturer has chosen 

to remain at 120,000 mile useful life. (Note that the timing of the requirement to certify

on the new test fuel would follow the same approach as for the useful life requirement 

(i.e., based on the first year a model is certified to Bin 70 or below) as described in 

Section IV.A.7.c below.) 

 

271 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.

272 PM, CO, and HCHO
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We request comment on the proposed useful life provisions, including the 85 

percent factor we propose to use to establish the standards for the 120,000 mile useful 

life. 

c. Test Fuels

We recognize that test fuels are an important element of a national program. 

Vehicle manufacturers have emphasized the desire to reduce test burden by producing 

one vehicle that is tested to a single test procedure and a single fuel and meets both 

California and federal requirements. Although we have been able to reasonably align the 

proposed Tier 3 program with the LEV III program in most key respects, we recognize 

that there would still exist some differences in emissions performance between vehicles 

operated on the LEV III and Tier 3 certification fuels. The largest differences between 

the two fuels are the amount of ethanol they contain and the Reid Vapor Pressure (RVP). 

The proposed Tier 3 NMOG+NOX standards assume operation on federal certification 

fuel. 

We propose that manufacturers begin to certify vehicles on the new Tier 3 fuels273

beginning with the first model year that a vehicle model is certified to the FTP 

NMOG+NOX Bin 70 or lower, independent of its useful life. The new-fuel requirement 

would apply beginning in MY 2017. Beginning in MY 2020, all gasoline-fueled models 

would need to certify on the new fuel, regardless of their certification bin.274 As 

discussed in Section IV.A.7.b above, manufacturers would also need to apply the 150,000 

mile useful life value to these same vehicles as they begin to be certified to Bin 70 and 

lower. 

During the transition period from Tier 2 fuel to the new Tier 3 and LEV III fuels, 

manufacturers have indicated a substantial workload challenge of developing and 

certifying a vehicle to the two new fuels simultaneously. To address this potential 

workload and certification challenge, we propose that vehicles certified in MY 2015 

through 2019 to California LEV III standards using California LEV III certification fuels 

and test procedures could be used for certifying to EPA standards. (For example, for MY 

2015 and 2016, EPA would consider such vehicles to be Tier 2 vehicles, although they

could be tested on California LEV III fuel.275 Similarly, for MY 2017 through 2019, 

EPA would consider such vehicles to be Interim Tier 3 vehicles, although they could be 

tested on California LEV III fuel.) For these vehicles only, we would not perform or 

require in-use exhaust testing on Tier 3 fuel. 

 

273 This includes fuels used for low temperature and high altitude testing and durability requirements. See 

Section IV.D below. 

274 Diesel fueled and alternative fueled vehicles would continue to test on the fuels used under the Tier 2 

program. 

275 Because the Tier 2 program has NOX fleet average standards (instead of the NMOG+NOX fleet average 

standard of LEV III and Tier 3), manufacturers certifying to LEV III standards in MY 2015 and 2016 

would not include such vehicles in their Tier 2 NOX fleet average calculation. Tier 2 provisions that are not 

a part of the California program would still apply. For example, high altitude testing, which is only 

required in the federal program, would still need be performed on federal Tier 2 fuel. 
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California does not have fuel specifications for high altitude testing or cold CO 

and hydrocarbon testing. For this reason, we are proposing that for vehicles that 

manufacturers choose to certify using LEV III fuel and test procedures, they can use test 

fuels meeting either Tier 2 or Tier 3 fuel specifications to comply with these federal-only 

requirements. We would perform in-use testing for these vehicles on the same fuel as 

selected by the manufacturer at certification. 

Certifications after MY 2019, however, would be required to use the Tier 3 fuel 

and carry-over certifications using LEV II, LEV III or Tier 2 certification fuels would not 

be allowed after MY 2019. CARB has indicated that they would accept Tier 3 test data 

(on federal certification fuel) 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 as vehicles certified to LEV III using federal certification fuel could obtain Final Tier 

3 status.276 

d. 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). 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 

increase. Vehicles under the Tier 2 program typically had sufficient compliance margins 

to absorb this increase in emissions during testing under high-altitude conditions.

However, given the near-zero standards we are proposing in Tier 3, vehicles 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 would also provide very significant emission 

control at high altitude.277 However, as explained above, unique emission challenges 

exist with operation at higher altitude. The stringency of the Tier 2 standards is such that 

manufacturers comply with the same standards at all altitudes without the need to design 

their emission control strategies specifically for the more challenging high altitude 

operation. The Tier 3 stringency may not allow manufacturers emission control strategies 

at lower altitude to maintain sufficient compliance margin when tested at higher altitude,

therefore requiring manufacturers to design their emission controls specifically for higher 

altitude. 

 

276 That is, a manufacturer that certifies a vehicle to LEV III in MY 2015 and MY 2016. 

277 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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To avoid requiring special high-altitude emission control technologies, we 

propose to allow manufacturers the limited relief of complying with the next lessstringent bin for testing at high altitude for vehicles certified at sea level to Bin 20, 30, 

and 50 (e.g., certifying 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, 35 mg/mi of relief will be provided. 

No relief is proposed for Bin 160. 

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 

technologies to be applied specifically for high-altitude conditions. In addition, this 

provision is intended to be applicable to all Final Tier 3 vehicles for the duration of the 

Tier 3 program. 

While vehicles would need to meet the Tier 3 standards at all intermediate 

altitudes, the question remains as to what the value of the standard should be at a given 

intermediate altitude. We request comment on both the level of the proposed high altitude 

standards and the appropriate level of the standard at intermediate altitudes. In particular, 

we seek comment on whether this could be addressed by requiring that all emission 

control strategies remain in effect at altitudes that are in between the specific altitudes 

used for high and low altitude testing and that any altitude-related auxiliary emission 

control device (AECD) must be identified by the manufacturer and justified as not being 

defeat devices.

Table IV-9 Proposed 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

e. 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 

preventing increases in these NOX emissions as manufacturers develop new or improved 

engine and emission control technologies. 

For this reason, we are proposing that the same FTP NMOG + NOX standards 

proposed 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 FTP 

NMOG+NOX standard for the bin at which a manufacturer has chosen to certify a vehicle 
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would 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 would simply need to ensure that the same emission control 

strategies implemented for the FTP and SFTP cycles were also effectively utilized during 

the highway test cycle. We believe that this proposed requirement would not require 

manufacturers to take any unique technological action, would not add technology costs, 

and would not add significantly to the certification burden. We request comment on this 

proposed provision. 

f. Interim 4,000 mile SFTP Standards

During the period of the declining NMOG+ NOX standards, we are proposing 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 are designed to prevent 

excessive emission levels from a single vehicle or a single SFTP cycle, which can occur 

if only a composite approach is taken. Under the Tier 3 program, the proposed composite 

standards would be fleet average standards that would decline from 2017 until 2025, as 

described in Section IV.A 4. While this approach is expected to result in fleet-wide 

reductions in SFTP emissions during all years of the declining standard, the level of the 

fleet average requirement during the initial years provides an opportunity for backsliding 

of SFTP emissions on individual vehicles or on individual SFTP cycles. We believe it is 

appropriate to require any individual Interim Tier 3 vehicle to at a minimum meet the 

same requirements under the Tier 2 and LEV II programs. Table IV-10 below presents 

the proposed 4,000 mile SFTP standards for interim Tier 3 vehicles.

Table IV-10 Proposed 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 (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. 

Additionally, once the program reaches 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. We seek comment on this proposed 

4,000 mile SFTP provision. 
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g. Phase-in Schedule

As described in Section IV.A.3, under the proposed Tier 3 program, 

manufacturers would be required to certify each vehicle model to an FTP bin, which 

would then be used to calculate the NMOG+NOX fleet average of all of its vehicles. 

Manufacturers would also need to 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 would 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.b and IV.A.7.c above, the longer (150,000 mile) 

useful life value, as applicable, and the new Tier 3 certification fuel for exhaust testing 

would be implemented as manufacturers certified 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 would be 

required to be certified on Tier 3 test fuel. In addition, any vehicle certified to Bin 70 or 

lower that would be required to meet the longer 150,000 mile useful life would be 

required to do so. Beginning in MY 2020 all vehicles would be required to be certified to 

on the Tier 3 test fuel, regardless of the bin they are certified to or the useful life they are 

required to meet.

Manufacturers would also be required to 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, would be independent of the fleet average 

requirements described above. The PM emission standards for FTP and SFTP described 

in Section IV.A.3 and 4 respectively would be implemented as a percent phase-in 

requirement as described below under a basic phase-in schedule or under an optional

phase-in schedule.

Vehicles certified to a Tier 3 bin, meeting the requirements of the PM phase-in 

schedule, and complying with the other Tier 3 requirements (i.e., 150,000 mile useful life 

(as applicable) and Tier 3 certification fuel, as applicable) would 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 would be considered “Interim Tier 3” compliant 

vehicles. At the completion of the percent phase-in period for PM (2021 for the basic 

PM phase-in schedule and 2022 for the alternative PM phase-in schedule, as described 

below), 100 percent of vehicles would need to meet the all Tier 3 requirements and would 

be considered “Final Tier 3” vehicles. 

For the PM requirements, each year manufacturers would be required to meet 

either the basic PM percent phase-in or alternative PM phase-in as described in the 

following subsections. The basic percent PM phase-in schedule is composed of fixed 

yearly minimum phase-in percentages that we expect that most manufacturers would 

meet to comply with the Tier 3 requirements. The alternative PM phase-in schedule 

provides additional flexibility for manufacturers with product offerings that may not 

provide sufficient vehicle model granularity to allow for a gradual transition into the 
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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 standard of 10 mg/mi and the SFTP weighted composite standard of 70 mg/mi. 

i. Basic PM Percent Phase-In Schedule

It is important to note that the percent phase-in of the new Tier 3 standards that 

we are proposing and the declining fleet average standards to which a manufacturer’s 

fleet is held are separate and independent elements of the Tier 3 program. “Phase-in” in 

this context means the fraction of a manufacturer’s fleet that would be required to meet 

the new Tier 3 PM standards in a given model year. We expect manufacturer fleets to 

consist of a mix of vehicles 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 

would be carried over into the Tier 3 program as Interim Tier 3 vehicles. A vehicle 

would be considered a “Final Tier 3 vehicle” when it is certified to one of the Tier 3 bins; 

meets the Tier 3 PM standards; certifies to the 150,000 useful life value (for LDT2s, 

LDT3s, LDT4s, and MDPVs); and certifies on the new certification test fuel. Table 

IV-11 below presents the proposed 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

In 2017 model year, a manufacturer may optionally include vehicles up to 8,500 lbs GVWR and/or 

MDPVs in its phase-in calculation.

ii. Optional PM Phase-in

The proposed PM percent-of-sales phase-in schedule described above would 

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 might have to over-comply with the 

required percentages earlier than would a manufacturer with many vehicle models 

available for the phase-in. 

For instance, a manufacturer with only two models that each equally accounted 

for 50 percent of their sales would be required to introduce (at least) one of the models in 
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MY 2017 meet the PM phase-in requirement of 20 percent in the first year. Because it 

represented 50 percent of the manufacturer’s sales, this model would 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 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 than would have been 

required of a manufacturer that was able to delay the final 30 percent of its fleet until MY 

2021 (by distributing its their 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 proposing an optional “indexed” PM phase-in 

schedule that could be used by a manufacturer to meet its PM percent phase-in 

requirements. A manufacturer that exceeded the phase-in requirements in any given year 

would be allowed to, in effect, offset some of the phase-in requirements in a later model 

year. The optional phase-in schedule would 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 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 would 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 proposed 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 anticipated phase-in percentage for the referenced model year. 

The sum of the calculation would need to 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 proposed optional PM phase-in equation to the hypothetical 

manufacturer in the example above, the manufacturer could postpone its model 

introductions by one year each, to MY 2018 and MY 2021. Its calculation would be (5 x 

0% + 4 x 50% + 3 x 50% + 2 x 50% + 1 x 100% = 550, and thus the phase-in would be 

acceptable. 

EPA requests comment on the proposed PM phase-in schedules.

h. In-use Standards 

i. NMOG + NOX

The proposed Tier 3 emission standards would require a substantial migration of 

emission control technology historically used only on a small percent of the fleet and 
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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 would 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.

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 proposing temporarily-relaxed in-use NMOG+NOX standards that would 

apply to all vehicles certified to Bins 70 and cleaner as Interim or Final Tier 3 vehicles. 

The in-use standards would apply during the entire percent phase-in period (i.e., through 

MY 2021). The proposed in-use standards would be 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 vehicle.

 The proposed in-use NMOG + NOX standards are shown in Table IV-12. 

Table IV-12 Proposed 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

ii. PM

As with the proposed NMOG+NOX standards, the introduction of new emission 

control technologies or new applications of existing technologies (e.g., GDI, 

turbocharging, downsized engines) would create significant uncertainties for 

manufacturers about in-use performance over the vehicle’s useful life. We are proposing 

a temporary in-use FTP standard for PM of 6 mg/mi for all light duty vehicles and 

MDPVs certified to the Tier 3 full useful life 3 mg/mi standard. Since the Tier 3 PM 

standard has a percent phase-in schedule spread over several years, starting in 2017 with 

full phase-in completed in 2022, we are proposing that the in-use standard apply to all 
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vehicles certified to the new PM standards during the entire percent phase-in period (i.e., 

through MY 2021).

We are also proposing temporarily-relaxed in-use US06 PM standards. We 

propose in-use standards 5 mg/mi less stringent than the certification standards, or 15 

mg/mi for all light duty vehicles up to and including 6,000 lbs GVWR and 25 mg/mi for 

all light duty vehicles and light-duty trucks over 6,000 lbs GVWR and MDPVs. 

Consistent with the FTP in-use standards, these in-use standards would apply to all 

vehicles certified to the new PM standards during the entire percent phase-in period (i.e., 

through MY 2021).

EPA requests comment on the proposed in-use standards.

i. FFVs

Because of the physical and chemical differences in how emissions are generated 

and controlled between vehicles operating on 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 proposed Tier 3 

program. Historically, under the Tier 2 program, FFVs have only been required to meet 

all Tier 2 emission standards while operating on gasoline; 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, 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 would not add technological 

feasibility concerns beyond compliance on gasoline alone (or low-level blends like E10 

or E15). We are thus proposing that in addition to complying with the Tier 3 

requirements when operating on gasoline, FFVs also comply with both the FTP and the 

SFTP emission standards when operating on E85. This would include the requirement to 

meet emission standards for both gasoline 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 available fuels. However, for emission compliance 

demonstration purposes, we will continue to test on gasoline and the highest available 

level ethanol. 

EPA welcomes comment on this proposed approach to FFV compliance.
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j. 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, 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 propose 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.278 As with the California program, such a credit could not 

exceed 5 mg/mi NMOG. We invite comment on the appropriateness of this proposed 

DOR credit approach, including the application of the California methodology to the 

federal Tier 3 program. 

k. Credit for Adopting a 150,000-Mile Emissions Warranty

Under the Tier 3 standards proposed above manufacturers would be 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, as with the current 

Tier 2 program, 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 propose that a manufacturer providing its customers with a robust emission 

control system warranty of 15 years or 150,000 miles be eligible for a modest credit of 5 

mg/mi NMOG+NOX.

279

 Because of the significant liability that manufacturers would be 

accepting, we do not expect that the use of this credit opportunity would be widespread. 

 

278 EPA is incorporating the CARB DOR methodology by reference. 

279 Manufacturers choosing to comply with the standards for a 120,000 mile useful life for their LDVs and 

LDT1s would not be eligible for this extended warranty credit for those vehicles.
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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.280

We propose to use the same criteria for approving such a credit as does the 

parallel California program.281 Thus, in addition to committing to customers that failing 

emission controls would be repaired or replaced for 15 years/150,000 miles, 

manufacturers would also need to accept the liability that in the event that a specific 

emissions control device failed on greater than 4 percent of a vehicle model’s production, 

they would recall the entire production of that model for repair. EPA requests comment 

on this optional credit opportunity. 

l. Averaging, Banking, and Trading of Credits

An averaging, banking, and trading (ABT) program was established in the Tier 2 

program to provide for credits to be generated by certifying vehicles that perform better 

than the standards, for those credits to be used to offset vehicles that perform worse than 

the standards, and for credits to be banked for later use or traded to other manufacturers. 

The ABT program is largely unchanged by this Tier 3 proposal. In some cases, 

especially during the transitional years, there would be specific restrictions on the 

generation of credits, as described above. Also, we are proposing that Tier 3 credits 

expire after 5 years, consistent with the LEV II and LEV III programs and similar to the

basic credit carry-forward provisions in the recent light-duty and heavy-duty greenhouse 

gas rules. We invite comment on the ABT program in general, and specific comment on 

a longer Tier 3 credit life, including any flexibilities that this may provide and 

implications for record retention requirements by manufacturers.

m. Tier 3 Transitional Emissions Bins

In discussions with manufacturers, EPA has become aware that some vehicles 

may continue to be produced 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 thus to further facilitate the transition from Tier 2 to Tier 3, we 

will allow manufacturers to certify to the combined NMOG+NOX levels of these bins 

through MY 2019. Two proposed transitional Tier 3 bins, Bin 110 and Bin 85, would 

have NMOG+NOX standards on the FTP of 110 mg/mi and 85 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 would be identical to 

those for vehicles certified to the proposed Tier 3 Bin 125. Tier 3 SFTP standards would 

apply to these vehicles, and these vehicles would be included in the Tier 3 PM percent 

phase-in calculations.

 

280 Beardsley, M, et al. (2013, February). Updates to MOVES for the Tier 3 NPRM. Memorandum to the 

docket.

281 EPA is incorporating the CARB extended emission warranty provisions by reference.
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n. Compliance Demonstration

In general, we are proposing that manufacturers demonstrate compliance with the 

proposed Tier 3 light-duty vehicle emission standards in a very similar manner to current 

Tier 2 vehicle compliance (see §86.1860 of the proposed regulatory language). 

However, we propose for Tier 3 that manufacturers 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 proposed 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 

proposed Tier 3 provisions will 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 proposed nationwide compliance calculation approach would apply to 

vehicles as they become subject to the Tier 3 provisions, either the declining fleetaverage 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.282 

B. Tailpipe Emissions Standards for Heavy-Duty Vehicles 

1. Overview

We are proposing Tier 3 exhaust emissions standards for heavy-duty vehicles 

(HDVs) between 8,501 and 14,000 lbs GVWR that are certified to gram per mile 

standards on a chassis dynamometer. 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 

full-size pickup trucks and work vans certified as complete vehicles.283 Most are built by

companies with even larger light-duty truck markets, and as such they frequently share 

major design characteristics and potential emissions control technologies with their LDT 

counterparts. However, in contrast to the largely gasoline-fueled LDT fleet, roughly half 

of the HD pickup and van fleet in the U.S. is diesel-fueled, which is a consideration in 

 

282

 If EPA ultimately decided to continue the disaggregated approach to fleet compliance calculations, we 

could potentially base compliance with the proposed Tier 3 emission requirements on U.S. sales (i.e., sales 

in non-California and non-Section 177 states).

283 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 vehicle frontal area in excess of 45 square feet, 

and we are proposing that these vehicles also would be subject to the standards and other provisions 

applicable to Class 2b vehicles discussed in this section.
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setting emissions standards, as diesel engine emissions and control strategies differ from 

those of gasoline engines.

Manufacturers of diesel-fueled complete HDVs have the option under existing 

EPA regulations to satisfy EPA criteria emissions requirements for these vehicles by

using engines certified through engine dynamometer testing, but for the most part have 

chosen to certify whole vehicles on the chassis test. We are proposing to codify this 

common practice and require that diesel-fueled Class 2b and 3 complete Tier 3 vehicles, 

like their gasoline-fueled counterparts, be certified to the Tier 3 standards on the chassis 

test. The current prohibition in 40 CFR 86.1863-07(d) on averaging, banking, and 

trading (ABT) credit generation and use by chassis-certified diesel HDVs would be 

replaced by the proposed fleetwide averaging program. We are not proposing changes to 

the heavy-duty engine certification requirements at this time.

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 would be subject to Tier 3 requirements. 

We are not proposing to mandate chassis certification of incomplete Class 2b and 3 

vehicles, but we note that California’s LEV III program does include such a requirement 

for Class 2b and we request comment on doing the same in the federal program. We 

further note that MDPVs are classified as HDVs under the Clean Air Act but, as in our 

current Tier 2 program, would be covered as part of our Tier 3 light-duty program 

discussed in Section IV.A, and not in the proposed program described here.

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

proposed for passenger cars and 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, new stringent PM standards phasing in on a separate schedule, changes to the 

test fuel for gasoline- and ethanol-fueled vehicles, extension of the regulatory useful life 

to 150,000 miles, and a new requirement to meet standards over the SFTP that would 

address real-world driving modes not well-represented by the FTP cycle alone. We 

believe that other requirements already in place for HDV testing and compliance remain 

appropriate. In particular, we believe the current HDV certification requirement to test at 

the adjusted loaded vehicle weight (ALVW), equal to vehicle curb weight plus one-half 

the payload weight, is more appropriate for these heavy-duty work trucks and vans than 

the LDT requirement to test at curb weight plus 300 lbs. These differences from lightduty requirements also factor into the evaluation of potential control technologies and 

subsequent choice of standards levels, as discussed below.

As with the proposed light-duty Tier 3 program, we are putting strong emphasis 

on coordinating this HDV Tier 3 proposal 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 
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manufacturers to comply nationwide by marketing a single vehicle fleet. With this goal 

in mind, we discuss the relationship of the proposed HDV Tier 3 program provisions to 

LEV III throughout this section. As part of this effort, we are proposing that 

manufacturers of Tier 3 HDVs calculate compliance with the fleet average standards and 

percent phase-in standards discussed in this section based on annual nationwide sales, 

including sales in California and Clean Air Act Section 177 states. This would help to 

create an effectively nationwide program, which has been a basic principle in EPA’s 

development of this proposed program and broadly supported by vehicle manufacturers. 

If this proposed approach to HDV fleet compliance calculations is not adopted, EPA 

could base compliance with the proposed Tier 3 requirements on U.S. sales outside of 

California and the Section 177 states.

Furthermore, in 2011 EPA and NHTSA set first-ever standards for GHGs and fuel 

consumption from HD pickups and vans (as well as other heavy-duty vehicles and 

engines). These standards phase in over 2014-2018, so in developing the Tier 3 HDV 

proposal we have carefully taken this new program into account to maximize the 

coordination between the two complementary heavy-duty regulatory programs and avoid 

inconsistencies.

2. HDV Exhaust Emissions Standards

a. Bin Standards

We are proposing that manufacturers certify HDVs to Tier 3 requirements by

having them meet the standards for one of the bins listed in Table IV-13. Manufacturers 

would choose bins for their vehicles based on their product plans and corporate strategy

for compliance with the fleet average standards discussed in Section IV.A.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 would gradually 

shift from higher to lower bins. As in the past, we are proposing 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 proposed standards levels for both Class 2b and Class 3 

HDVs are significantly higher than those being proposed 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 ALVW). By conducting emissions testing with loaded vehicles, 

the heavy-duty program ensures that emissions controls are effective when these vehicles 

are performing their core function: hauling heavy loads. This is a key difference between 

the heavy-duty and light-duty truck programs. The proposed bin structure and standards 

levels are consistent with those in the LEV III program. We request 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.
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Table IV-13 Proposed FTP Standards for HDVs

NMOG

+NOX

(mg/mi)

NMOG

(mg/mi)

NOX

(mg/mi)

PM

(mg/mi)

CO

(g/mi)

Formaldehyde

(mg/mi)

Class 2b (8,501-10,000 lbs GVWR):

Bin 395 (interim) -- 195 200 8 6.4 6

Bin 340 (interim) -- 140 200 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) -- 230 400 10 7.3 6

Bin 570 (interim) -- 170 400 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 proposed NMOG and NOX standards for the highest bins in each class (Class 

2b Bin 395 and Class 3 Bin 630) are equal to the current non-methane hydrocarbon 

(NMHC) and NOX standards 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 would 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 proposed 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 

would 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) would be 

considered “interim Tier 3” vehicles, and the bins themselves would be considered 

“interim bins.”

To facilitate their use in this carryover function, we are proposing that the interim 

bins not include SFTP requirements, longer useful life requirements, or requirements to 

conduct exhaust emissions testing with the proposed new gasoline test fuel discussed in 

Section IV.D, although testing on this fuel would be allowed. For gasoline-fueled HDVs 

in all other bins, we are proposing that exhaust emissions testing be conducted with the 

new test fuel. (See Section IV.D.5 for discussion of our request for comment on 
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extending this requirement to testing of gasoline-fueled heavy-duty engines as well.) In 

the context of these proposed accommodations for the interim bins, we propose two 

additional measures to help ensure these bins are focused on their function of helping 

manufacturers transition to Final Tier 3 vehicles. First, we propose that the interim bins 

be available only in the phase-in years of the program, that is, through MY 2021, as is 

appropriate to their interim status.

Second, we are proposing that vehicles in the interim bins meet separate NMOG 

and NOX standards, as indicated in Table IV-13, rather than combined NMOG+NOX

standards. This proposed provision is intended to keep a manufacturer from redesigning 

or recalibrating a vehicle design 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. We note that other, more stringent, proposed bins also carry 

this potential but to a lesser degree, and we feel their relatively low NMOG+NOX

standards levels sufficiently mitigate this concern, whereas the interim bins have the 

potential to allow a doubling of emissions or more. We request comment on this issue 

and the proposed approach to addressing it.

b. Fleet Average NMOG+NOX Standards

As in the light-duty program, a key element of the Tier 3 program 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. For the interim bins, with separate NMOG and 

NOX standards, the NMOG+NOX level is the simple sum of the NMOG and NOX

standards. 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. 

We are proposing the separate Class 2b and Class 3 fleet average standards shown in 

Table IV-14, though a manufacturer could effectively average the two fleet classes using 

credits (see Section IV.B.4). We believe this split-curve approach is superior to a single 

HDV phase-in because it recognizes the different Class 2b/Class 3 fleet mixes among 

manufacturers and the different challenges in meeting mg/mi standards between Class 2b 

and Class 3 vehicles, while still allowing for a corporate compliance strategy based on a 

combined HDV fleet through the use of credits. 

The proposed fleet average standards are consistent with those set for the MDV 

LEV III program in model years 2018 and later. Note that the LEV III program also sets 

standards for model years before 2018, something EPA is not requiring due to lead time 

considerations. However, we are proposing that manufacturers may voluntarily meet bin 

and fleet average standards in model years 2016 and 2017 that are consistent with the 

MDV LEV III standards, for the purpose of generating credits that can be used later or 

traded to others. These proposed voluntary standards are shown in Table IV-14. This 

proposed 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 
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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.

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, including SFTP standards, but not 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 also requesting comment on extending the voluntary

compliance opportunity to the 2015 model year.

Table IV-14 Proposed 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 offering this voluntary opt-in would 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. We request comment on all facets of this 

proposed approach.

Although manufacturers would 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 would 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. 

The Tier 3 program we are proposing for HDVs would result in substantial 

reductions in harmful emissions from this large fleet of work trucks and vans, vehicles 

that are typically driven over high annual miles on every part of the nation’s highway and 

urban roadway system. The Final Tier 3 standards levels for NMOG+NOX and PM are 

on the order of 60 percent lower than the current stringent standards that took full effect 

three years ago.
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c. Alternative NMOG+NOX Phase-in

We believe that the program described in Sections IV.B.2.a and b above would 

provide manufacturers with a flexible and effective compliance path. However, as in the 

case of the light-duty standards discussed above, we are proposing to provide an 

alternative compliance path that would be available to any manufacturer who prefers a 

stable standard and four full years of lead time, as specified in the Clean Air Act.284 This 

alternative approach would be equivalent to the primary approach that is based on 

NMOG+NOX declining fleet average standards and would apply during the program 

phase-in over the 2016-2022 model years, with the first three of those model year 

standards made voluntary and set at levels to align with the California LEVIII program. 

We are proposing an alternative phase-in structured to require an 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.

Table IV-15 Proposed Percent-of-Sales Alternative NMOG+NOX Phase-in

Voluntary Required Program

Model 

Year 2016 2017 2018 2019 2020 2021 2022 and later

Class 2b 29% 39% 54% 65% 77% 88% 100%

Class 3 21% 32% 47% 60% 73% 87% 100%

Under our alternative phase-in proposal, the availability of emissions averaging 

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. Although we are proposing to make the alternative 

approach available, we believe that the primary approach – the declining fleet average 

standard discussed above - is more consistent with the approach taken in California’s 

LEV III program and in recent GHG reduction rules.

To help ensure that the percent-of-sales alternative is fully equivalent to the 

primary program in terms of fleet-wide emissions control and technology mix choices, 

we are proposing that it include some additional provisions. First, we are proposing that 

the Tier 3 vehicles being phased in under the percent-of-sales alternative, in addition to 

meeting the fully phased-in NMOG+NOX FTP standards, must also meet all other FTP 

and (as described below) SFTP standards required by the primary compliance program. 

 

284 For vehicles above 6,000 lbs GVWR, CAA 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 HC, NOX, 

CO or PM can be implemented, and 3 years of stability between changes to any such standard.
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These include the CO and formaldehyde FTP standards in Table IV-13, the 150,000 mile 

(15 year) useful life requirement, exhaust emissions testing with the new test fuel for 

gasoline- and ethanol-fueled vehicles discussed in Section IV.D, and the NMOG+NOX

and CO SFTP standards in Table IV-16. The specific proposed 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 proposing to make an ABT program available for the percent-ofsales alternative, structured like the one proposed for the primary option. This would 

involve certifying the vehicles in a manufacturer’s HDV fleet to the bin standards in 

Table IV-13, and demonstrating compliance with the fleet average standards for the 

primary program in each model year, including through the use of ABT credits as in the 

primary program. We are proposing to use 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 proposing one difference between the primary and alternative 

options with respect to ABT provisions. Unlike in the primary option, manufacturers 

would 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 would not be 

subject to the Tier 3 standards or other vehicle-specific elements of the Tier 3 compliance 

program. For the purposes of the fleet average ABT calculation, the NMOG+NOX levels 

for these non-Tier 3 vehicles would be set equal to the sum of the NMOG and NOX

standards for the highest bins: 395 mg/mi for Class 2b and 630 mg/mi for Class 3, 

because these standards are numerically equal to the pre-Tier 3 NMHC and NOX

standards.

d. Phase-in of PM Standards

Consistent with the light-duty Tier 3 proposal discussed in Section IV.A, we are 

proposing to phase 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. 

The reasons discussed in Section IV.A for this phase-in schedule in the light-duty sector 

also apply to the heavy-duty sector. 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 GHG standards. 

Therefore we are proposing the same phase-in schedule as proposed for the light-duty

sector in model years 2018-2019-2020-2021: 20-40-70-100 percent, respectively. This 

would apply to HDVs certified under either NMOG+NOX phase-in alternative. The 
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California Air Resources Board is phasing in the LEV III PM standards for HDVs on the 

same schedule, except that LEVIII would also involve a 10 percent PM phase-in in the 

2017 model year, and we ask for comment on our doing so as well, in the context of the 

voluntary opt-in discussed in Section IV.B.2.b. The voluntary NMOG+ NOX and PM 

standards may be pursued separately, with no requirement that they be met on the same 

vehicles. 

For manufacturers choosing the declining fleet average NMOG+NOX compliance 

path, the PM phase-in requirement for HDVs would be completely independent of the 

NMOG+NOX phase-in. As a result, vehicles certified to any of the bin standards for 

NMOG and NOX need not necessarily meet Tier 3 PM standards before the 2021 model 

year. Instead, the current 0.02 g/mi PM standard would apply for those vehicles not yet 

phased into the Tier 3 PM standards. We are proposing that manufacturers choosing the

percent-of-sales phase-in alternative for NMOG+NOX would be required to meet the PM 

phase-in requirements with only those vehicles certified to the Tier 3 NMOG+NOX

standard, except in the 2018 and earlier model years when the standards, including the 

PM standards, would be 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. 

Consistent with the approach we are proposing for the light-duty sector, we would 

consider any vehicle under either compliance path that is not certified to Tier 3 standards 

for PM, NMOG, and NOX (as well as the other, concomitant Tier 3 standards and 

requirements such as extended useful life), an “Interim Tier 3” vehicle, a term that also 

applies to vehicles certified in one of the interim bins, as discussed above.

Note that compliance with Tier 3 evaporative emissions requirements would 

follow a separate phase-in schedule as described in Section IV.C, such that a vehicle in 

an exhaust emissions family that the manufacturer has phased into the new useful life and 

test fuel requirements, may be in an evaporative emissions family that has not yet phased 

these in for evaporative emissions testing.

i. Optional PM Phase-in

The proposed percent-of-sales phase-in schedule for the PM standard, described 

above, would allow manufacturers with multiple vehicle models to determine and plan 

the phase-in of those models based on anticipated volumes of each vehicle model. 

However, manufacturers certifying only a few vehicle models may not be able to take 

advantage of 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 

would a manufacturer with many vehicle models available for the phase-in. 

For instance, a manufacturer with only two models that each equally accounted 

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 
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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 redesigned 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 proposing an optional “indexed” phase-in schedule 

that could be used by a manufacturer to meet its phase-in requirements. A manufacturer 

that exceeded the phase-in requirements in any given year would be allowed to, in effect, 

offset some of the phase-in requirements in a later model year. The optional phase-in 

schedule would 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 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 would 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 proposed mathematical equation for applying an optional phase-in is as 

follows:

(4 x APP2018) + (3 x APP2019) + (2 x APP2020) + (1 x APP2021) ≥ 440, 

where APP is the anticipated phase-in percentage for the referenced model year. The sum 

of the calculation would 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). EPA requests comment on this proposed 

optional phase-in mechanism.

e. NMOG+NOX and NMOG vs. NMHC

The reasons for setting combined NMOG+NOX standards outlined in Section 

IV.A.1.a for the light-duty sector apply to HDVs certified in the non-interim Tier 3 bins 

as well. In fact, the combined standard is especially appropriate in the heavy-duty sector 

with comparable sales of diesel and gasoline-fueled vehicles, because it avoids the need 

to set “lowest common denominator” standards for NMOG (likely based on feasible 

gasoline vehicle technologies) and NOX (likely based on feasible diesel vehicle 

technologies). These considerations also apply to the form of the SFTP standards, 

discussed below.

The current HDV standards that control emissions of volatile organic compounds 

(VOCs), adopted in a 2001 final rule,285 are in the form of NMHC. This is consistent 

with HD engine standards adopted in the same final rule, but contrasts with Tier 2 

LDV/LDT standards to control VOCs that are in the form of NMOG. We believe it is 

appropriate to transition HDVs to NMOG-based standards, and further to combined 

 

285 66 FR 5002 (January 18, 2001).
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NMOG+NOX standards, consistent with the light-duty Tier 3 proposal and light- and 

medium-duty LEV III program. Further, the introduction of oxygenated test fuels 

requires an NMOG calculation to properly control VOC emissions not properly

accounted for in an NMHC calculation. This would improve consistency with the LEV 

III program and help to facilitate a single nationwide vehicle fleet. We do not believe 

that this change would add significant cost to the program as manufacturers are already 

capable of and experienced in making NMOG determinations at their test facilities.

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. 

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 would also help make the HDV program 

more consistent with the HD engine program, which for several years has included “notto-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 proposed SFTP standards levels are provided in Table IV-16. These are 

consistent with those in the LEV III program.

Table IV-16 Proposed SFTP Standards for HDVs

Vehicles in 

FTP Bins:

NMOG+NOX

(mg/mi)

PM

(mg/mi)

CO

(g/mi)

Class 2b with horsepower (hp)/GVWR ≤ 0.024 hp/lb:a

FTP Bins 200, 250, 340 550 7 22.0

FTP Bins 150, 170 350 7 12.0

Class 2b:

FTP Bins 200, 250, 340 800 10 22.0

FTP Bins 150, 170 450 10 12.0
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Class 3:

FTP Bins 270, 400, 570 550 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 proposing that Tier 3 SFTP implementation for HDVs be linked 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 would phase in on a separate schedule, we 

propose to 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. There are no proposed 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 aid the transition to Tier 3, and 

therefore are not intended to prompt vehicle redesigns to new standards. These 

implementation provisions are consistent with the approach taken in the LEV III 

program, except that California would allow FTP and SFTP phase-in requirements to be 

met on different vehicles, and would apply more of the Tier 3 requirements for SFTP and 

extended useful life to vehicles in the interim bins. We request comment on the proposed 

standards, and on whether or not EPA should adopt any LEV III provisions that differ 

from what we are proposing, such as the application of PM SFTP standards to vehicles 

that are in the interim bins and that also are certified to the Tier 3 PM FTP standards.

To help ensure a robust SFTP program that achieves good control over a wide 

range of real world conditions, the current Tier 2 light-duty program adopted a weightedcomposite cycle, and we are proposing to retain this approach for light-duty Tier 3 

testing, as discussed in Section IV.A.1.c. Under this composite cycle, NMOG+NOX

emissions are 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. We considered 

applying the same composite cycle for all HDV SFTP testing. However, based on data 

provided by industry stakeholders, we decided that the full US06 cycle, combined with 

the ALVW loaded test condition, would not be sufficiently representative of real-world 

driving for two groups of HDVs: those with low power-to-weight ratios and Class 3 

vehicles. 

As part of their investigation of potential LEV III SFTP standards for MDVs, 

California Air Resources Board staff determined that it is not uncommon for vehicles 

above 8,500 lbs GVWR with low power-to-weight ratio, which are largely in Class 2b, to 

have to work extremely hard to keep up with the accelerations required in the initial and 

final portions of the full US06 cycle, even proving physically unable to do so in some 

cases, and raising the concern that these vehicles would not be able to run a valid 
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emissions test.286 Although our SFTP provisions allow a test to continue when a vehicle 

is incapable of attaining the vehicle speed demanded by the drive trace, we believe 

routine occurrence of such an event for a group of vehicles would not be consistent with a 

well-designed test regime. We would expect results from such tests to exhibit significant 

test-to-test variability, making it difficult to draw reliable conclusions from them. 

Furthermore, in real-world driving, we would expect that most drivers who regularly 

demand and do not receive adequate response would modify either their driving behavior 

or their vehicle purchase decisions. 

Based on manufacturer-supplied data, the California Air Resources Board staff 

established a power-to-weight (GVWR) ratio of 0.024 horsepower (hp)/lb as an 

approximate threshold in their efforts to characterize this issue. The vast majority of 

Class 2b vehicles are above this threshold today. Those below it tend to be used in 

applications where towing is not done extensively and the need for cargo space is more 

important than payload weight. Furthermore, it is possible that this group of vehicles will 

grow as purchasers adjust to sustained high fuel prices and when EPA’s GHG standards 

and NHTSA’s new fuel consumption standards take effect.

In consideration of this matter, we are proposing that, in SFTP testing of Class 2b 

vehicles at or below 0.024 hp/lb, manufacturers may at their 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, subject to correspondingly lower SFTP standards levels 

discussed above. (These vehicles would still be driven during the test in the same way as 

the higher power-to-weight Class 2b vehicles (over the full US06 cycle) just using best 

effort (maximum power) if the vehicle cannot maintain the driving schedule.) The large 

majority of Class 2b vehicles, with power-to-weight above 0.024 hp/lb, would be 

required to measure and use emissions over the full US06 cycle in the composite SFTP. 

We believe that this approach would provide 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.

For Class 3 vehicles, which can weigh as much as 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 the way

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 would 

produce more robust results for use in SFTP evaluations. Therefore we are proposing 

that the LA-92 cycle be used in place of the US06 component of the composite SFTP for 

 

286 Letter from Robert H. Cross, California Air Resources Board, to Dawn Friest, EMA, dated March 2, 

2011.
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Class 3 HDVs. The set of composite SFTP cycles we are proposing is fully consistent 

with the MDV LEV III program.

Although we consider the highway portion of the US06 cycle appropriate for low 

power-to-weight vehicles, we also believe that the corresponding NMOG+NOX standards 

should be set at lower levels than for vehicles with emissions measured over the full 

US06 test. Our goal is to provide roughly equivalent stringency and avoid creating an 

ease-of-compliance incentive to produce vehicles in one group or the other. We have 

reviewed the MDV SFTP standards set by the California Air Resources Board staff and 

consider them appropriate in achieving this goal. These proposed standards are included 

in Table IV-16.

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 proposing that 

HDV manufacturers have the option to substitute the FTP emissions levels for the SC03 

emissions results for purposes of compliance. However, we would retain the ability to 

determine the composite emissions using SC03 test results in confirmatory or in-use 

testing.

b. Enrichment Limitation for Spark-Ignition Engines

To prevent emissions from excessive enrichment in areas not fully encountered in 

the SFTP cycles, we are proposing limitations in the frequency and magnitude of 

enrichment episodes for spark-ignition HDVs. These limitations would be identical to 

those for light-duty vehicles discussed in detail in Section IV.A.4.c.

4. HDV Emissions Averaging, Banking, and Trading

This section describes our proposed approach for emissions credits related to 

exhaust emissions. See Section V.C for similar provisions that apply for evaporative 

emissions. We are proposing to continue the current 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 this proposed Tier 3 ABT program for HDVs that would be different from the 

current program. First, instead of separate NMHC and NOX credits, manufacturers would 

earn combined NMOG+NOX credits, consistent with the form of the standards. Second, 

we are proposing to allow manufacturers to accrue a deficit in their credit balance. 

Deficits incurred in a model year may be carried forward for up to 3 model years, but 

must be made up with surplus credits after that to avoid noncompliance and possible 

penalties. Manufacturers would have to use any new credits to offset any shortfall before 

those credits can be traded or banked for additional model years. We are proposing that 

credits must be used within 5 years after they are earned, or otherwise be forfeited. The 

proposed 5/3-year credit/deficit life provisions are consistent with our proposed lightduty Tier 3 approach, the California LEV III program for MDVs, and EPA programs for 

controlling GHG emissions from light- and heavy-duty vehicles.
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Third, as part of our proposal to require chassis certification of complete diesel 

HDVs, we are proposing to allow diesel HDVs to participate in this ABT program 

without restriction. Currently, they are not allowed to earn or use ABT credits. We are 

not proposing to restrict or adjust 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.

We are proposing that credits earned by a Tier 3 HDV may be used to 

demonstrate compliance with NMOG+NOX standards for any other 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. HDV manufacturers are currently certifying their vehicles to existing standards 

without the use of NOX or NMHC credits, and the levels we are proposing for Tier 3 

standards are not based on any assumption of credit transfers into Tier 3. As a result, we 

are not proposing provisions for converting pre-Tier 3 credits, should any exist at the 

time, into Tier 3 credits, including for use in the interim bins.

In the past we have set caps, called family emission limit (FEL) caps, on how 

high emissions can be for vehicles that use credits, regardless of how many credits might 

be available. Under our proposed 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. Under this proposed approach, the standards for NMOG and NOX in the highest 

available bin serve the purpose of the FEL caps in previous programs.

We are proposing no 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 control on a vehicle that lacks commensurate FTP 

control, could prove at odds with the primary goal of the supplemental test for HDVs. 

However, we note that California’s LEV III program does provide some flexibility in this 

matter, on a vehicle-for-vehicle basis rather than through use of emissions credits, and for 

this reason we request comment on the need for and considerations surrounding our 

granting similar flexibility for HDVs in Tier 3.

5. Feasibility of HDV Standards

The feasibility assessment, discussed in more detail in Chapter 1 of the draft RIA, 

recognizes that the proposed Tier 3 program is composed of several new requirements for 

Class 2b and 3 heavy-duty vehicles, which include primarily large gasoline and diesel 
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pick-up trucks and vans with diverse application-specific designs. These proposed new 

exhaust emissions requirements include stringent NMOG+NOX and PM standards for the 

FTP and the newly proposed SFTP, that would as a whole require new emissions control 

strategies and hardware in order to achieve the proposed standards. The type of new 

hardware that would be required will vary depending on the specific application and 

emissions challenges. Additionally, gasoline and diesel vehicles would require different 

emissions control strategies and hardware. The level of stringency for the proposed 

SFTP NMOG+NOX standards would 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 would 

require more precise control of engine operation on gasoline vehicles while diesels 

already equipped with diesel particulate filters would 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. 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 4,000 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 proposed useful life of the Tier 3 program. 

Deterioration factors to adjust the values to the proposed Tier 3 useful life standard of 

150,000 miles were not available however deterioration factors to adjust to 120,000 miles 

useful life are discussed in the RIA Chapter 1. 

The analysis also reflects the importance of the NMOG+NOX standard approach 

where diesels and gasoline MDVs 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 4,000 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
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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 proposed 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 variability, manufacturers will need to reduce their emission levels considerably from 

the levels indicated in this data set, particularly diesel vehicles. 

However, as discussed above, these emission results do not include the expected 

emissions deterioration which would be determined by manufacturers during 

development and certification testing. Therefore, manufacturers would 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 2011heavy-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.287 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 proposed PM 

standards for the FTP and the SFTP, we based our conclusions on some testing of current 

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 proposed 

standards for both the Class 2b and Class 3 configurations. Data from light-duty gasoline 

 

287 76 FR 57106 (September 15, 2011).
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vehicles with similar or common engines with their heavy-duty “sister” vehicle models 

demonstrates that these vehicles are currently meeting the proposed 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 proposed for Tier 3. 

The SFTP test data from the same two heavy-duty vehicles described above 

indicates that gasoline vehicles can achieve the proposed 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 and SC03). Therefore, 

although the limited testing results had a high degree of variability, several tests met the 

proposed PM standards for the high power-to-weight Class 2b vehicles. Consistent with 

light-duty, vehicles that are demonstrating high PM on the US06 would need to control 

enrichment and oil consumption from engine wear. Manufacturers have confirmed that 

they have 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 proposed HDV exhaust 

emissions standards, discussed below, we consider the lead time available before the 

standards take effect under all of the proposed 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 proposed program incorporates a number of 

phase-in and alternative compliance provisions that would ease the transition to final 

standards without disrupting HD pickup and van product redesign cycles. Among these 

is an alternative phase-in that starts mandatory standards in model year 2019. We invite 

comment on our conclusions relating to the feasibility of the proposed program in the 

lead time we are proposing.

We are not proposing relaxed standards for in-use testing of Tier 3 HDVs because 

we do not believe additional flexibility provisions are needed to successfully implement 

the new emission control technologies in the proposed timeframe. However, we note that 

the LEV III program provides such standards for PM, and also for NMOG+NOX in the 

lower-emissions MDV bins (those at or below Bin 250 and Bin 400, for Class 2b and 

Class 3 vehicles, respectively), and we are taking comment on the need to do so in Tier 3 

as well.

We also note that the need for NMOG+NOX in-use testing standards is further 

mitigated by our proposed structuring of the NMOG+NOX standards as a declining fleet 

average with deficit and credit banking provisions. These provisions provide substantial 

flexibility to manufacturers in introducing any new NMOG or NOX control technologies 

for which long-term durability is not yet proven. Manufacturers can place any vehicles 

for which they have in-use performance concerns in a higher bin, and this is facilitated by 
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the fact that, unlike LEV III, our Tier 3 proposal does not target sales volumes for any 

individual bins. Comments supporting relaxed in-use NMOG+NOX standards should 

therefore address why, in the absence of these standards, the proposed declining fleet 

average standard is not feasible in one or more model years.

Commenters on this issue are asked to also address the applicable model years for 

any such in-use testing standards. The LEV III MDV program has four different 

applicability periods based on a combination of specific model years listed in the 

regulations (up to 2020) and a set number of model years (two or five) after a test group 

is first certified. Comments are requested on whether it might be preferable to adopt a 

simpler approach in Tier 3, such as making in-use testing standards available in the 

model years in which standards are phasing in, that is, through model year 2021. 

i. Technologies Likely to be Applied

The technologies expected to be applied to vehicles to meet the lower proposed 

standards levels would 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 

would 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 calibration changes, thermal management, close-coupled catalysts, catalyst 

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 
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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 Platinum Group Metal (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 would need 

to 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 would also help reduce emissions levels. 

6. Other HDV Provisions

a. 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 proposing to extend the useful 

life to 150,000 miles or 15 years, whichever occurs first. This change would better 

reflect the improvements in vehicle durability and longevity that have occurred in the 

several years since the 120,000 mile useful life was established, and would maintain 

consistency with the LEV III MDV program and with our Tier 3 program for large LDTs, 

for which the same useful life period has been proposed. California’s LEV III staff paper 

included a discussion of the feasibility of this longer useful life based on experience with 

it in the PZEV element of the ZEV mandate.288

We are proposing that the new useful life requirement apply 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 

would 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 2016 or 2017. For manufacturers choosing the alternative percentof-sales NMOG+ NOX alternative, we are proposing that the new useful life requirement 

apply to all HDVs counted toward the phase-in requirement, resulting in a generally 

equivalent useful life phase-in rate to that of the primary approach. See Section IV.D.4.b 

for further discussion of useful life with regard to GHG standards. We are also proposing 

 

288 “Preliminary Discussion Paper – Amendments to California’s Low-Emission Vehicle Regulations for 

Criteria Pollutants – LEV III”, California Air Resources Board, February 8, 2010.
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that manufacturers may optionally retain the 120,000 mile/11 year useful life for PM on 

interim Tier 3 vehicles that are not phased in to the Tier 3 PM standards.

b. Heavy-Duty Alternative Fuel Vehicles

As in the proposed light-duty program, we are proposing that manufacturers 

demonstrate heavy-duty flex 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 would 

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.

c. Optional Certification for Vehicles above 14,000 lbs GVWR

The HD greenhouse gas (GHG) standards include a provision for optional 

certification of complete gasoline-fueled HDVs above 14,000 lbs GVWR to g/mi GHG 

standards on the chassis test.289 Because that rule does not change the requirements for 

certification to criteria pollutant standards, manufacturers choosing this option would 

have to certify the vehicle for GHGs, but use installed engines certified to g/hp-hr 

standards for all other emissions. We believe it may provide benefits for both the 

environment and the manufacturers to allow consistent certification of these vehicles on a 

chassis test for all emissions, treating any vehicles so certified in the same way as Class 3 

vehicles, including applicable standards, inclusion into fleet average calculations, test 

fuel, useful life, and the application of Tier 3 evaporative emissions requirements. 

We request comment on the value of, and any issues concerning, our providing 

such an option to manufacturers of both gasoline and diesel-fueled HDVs above 14,000 

lbs GVWR, including the applicability of the existing chassis test cycles for these larger 

trucks. Comment is also requested on whether manufacturers of such vehicles that are 

certified to a Final Tier 3 bin should be allowed to exclude them from the fleet average 

NMOG+NOX calculation, as a means of encouraging the production of such lowemissions vehicles by not penalizing them for having emissions somewhat above the 

Class 3 fleet average. Finally, we also request comment on whether any such option for 

diesel-fueled HDVs should extend to GHG emissions as well.

 

289 76 FR 57106 (September 15, 2011).
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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. We 

are proposing to eliminate this provision. We believe that the PM standards we are 

proposing for these vehicles are of sufficient stringency that routine waiver of testing 

would not be appropriate. The California Air Resources Board LEV III program 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. Even so, we request comment on alternative 

approaches, such as that being proposed for light-duty vehicles, involving measuring PM 

on a subset of families each year. We request comment on any other potential situations 

in which waiver of PM measurement may be appropriate. Note that we are proposing to 

waive the PM emissions measurement requirement for small manufacturers, for reasons 

explained in Section IV.E. 

e. Meeting HDV Standards in Fuel Consumption and GHG Emissions Testing

As with the proposed light-duty Tier 3 program, we are proposing that 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 proposed requirement is design forcing. 

Rather, we are proposing this requirement to ensure that test vehicle calibrations are not 

set by manufacturers to minimize fuel consumption and GHG emissions, at the expense 

of 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 proposing that PM emissions testing be included in this 

requirement, but we ask for comment on whether we should instead include them, but 

waive the requirement to measure them in manufacturers’ certification testing, to ensure 

that any unforeseen PM control technology challenges in highway driving conditions are 

addressed in the future.

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 do not anticipate that the 

proposed FTP bin standards would require the use of special hardware to achieve 

compliance at altitude. We also do not believe that adjustment to the FTP standards is 

appropriate for HDV testing at altitude, as we expect that manufacturers would be able to 

meet these standards with adequate compliance margin to cover this test condition. As in 

the proposed light-duty program, and for the same reasons, we are not proposing to 

require that HDVs comply with SFTP standards at altitude.
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C. Evaporative Emissions Standards and Onboard Diagnostic System 

Requirements

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. These evaporative emissions from gasoline-powered vehicles 

which occur on a daily basis are primarily functions of temperature, fuel vapor pressure, 

and activity. 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 to address resting losses (e.g., permeation). Onboard refueling 

vapor recovery (ORVR) requirements for control of refueling 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. 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 highway motor vehicles. Vehicles demonstrating near zero fuel vapor 

emissions have been certified by CARB and a limited number are in-use in California and 

other states. Furthermore, test programs conducted by the Coordinating Research 

Council and EPA show that attention is needed to insure better in-use performance of 

current evaporative control systems. Cost effective hydrocarbon emission reductions can 

be achieved through new vehicle standards and improved focus on in-use performance. 

This section discusses the proposed vehicle-related evaporative emission 

standards and related provisions for LDVs, LDTs, MDPVs, and HDGVs. As discussed 

below, we are proposing more stringent standards that would apply for the 2- and 3- day

evaporative emissions tests, a new canister bleed test and emission standard, a new 

certification test fuel specification,290 and a new fuel/evaporative system leak test 

procedure and emission standard. We are also proposing refueling emission controls for 

a portion of HDGVs over 10,000 lbs gross vehicle weight rating (GVWR). This section 

also describes proposed phase-in flexibilities, credit and allowance programs, and seeks 

comment on several other issues related to evaporative emissions control. 

The proposed evaporative emissions program has six basic elements: (1) the Tier 

3 evaporative emission phase-in program (MY 2018-2022+), (2) the early 

 

290 For flexible fuel vehicles (FFVs) certification fuel for evaporative and refueling emissions testing would 

remain a 9 RVP gasoline splash blended with ethanol to yield a blend containing 15 percent ethanol. 
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allowance/credit program (MY 2015-2016), (3) the transitional program (MY 2017), (4) 

requirements for HDGVs including ORVR, (5) a leak emission standard and test 

procedures, and (6) other miscellaneous proposed changes and areas for comment. 

In this proposed rule, the vehicle classifications, LDVs, LDTs, MDPVs, and 

HDGVs, would remain unchanged from Tier 2. For purposes of this discussion of the 

proposed 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), 

(3) vehicles meeting the proposed Tier 3 evaporative emissions program requirements 

using the proposed certification test fuel (9 RVP E15), and (4) transitional vehicles 

meeting current EPA evaporative requirements on Tier 2 certification fuel (9 RVP 

E0).291,292 For ease of reference these four categories may be referred to as PZEV evap, 

LEV III evap, Tier 3 evap, and Tier 2 evap in this section.293

1. Tier 3 Evaporative Emission Standards 

a. Proposed Standards

This proposal for evaporative emissions builds on previous EPA requirements as 

well as CARB’s recent LEV III rule which starts phasing in with the 2018 MY. This 

proposal facilitates a national program for vehicle evaporative emissions control. We 

believe the proposed program is appropriate since it would require new evaporative 

emissions control technology in new vehicles while also achieving improved in-use 

system performance. 

This section describes proposed requirements for LDVs, LDTs, MDPVs, and 

HDGVs. The proposal includes more stringent emission standards for hot soak plus 

diurnal emissions (2- and 3-day tests), plus a new canister bleed standard and testing 

requirement for measuring emissions from the fuel tank and the evaporative canister. 

The proposal also introduces a limited corporate averaging program for demonstrating 

compliance with the hot soak plus diurnal standards. We are proposing a phase-in of the 

Tier 3 evaporative emission standards that would begin with the 2017 MY, with 

incentives for manufacturers to introduce Tier 3 compliant vehicles earlier or in greater 

numbers than required. The proposal includes revised provisions for demonstrating 

compliance with the evaporative emission standards at high altitude. See Section IV.C.3

for additional provisions for the HDGV category.

 

291 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). 

292 See Section IV.D.1 for a discussion of the proposed certification fuel changes, including discussion of 

options for and implications of the certification test fuel having 10 percent ethanol.

293

 “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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i. Hot Soak Plus Diurnal Standards

Previous hot soak and diurnal emission controls have dramatically reduced 

vehicle evaporative emissions over the past thirty plus years. However, some emissions 

remain and control technology is available to capture these emissions in a cost effective 

manner. Toward that end, EPA is proposing more stringent hot soak plus diurnal 

evaporative emission standards for the Tier 3 program. The standards apply to both the 

2-day and 3-day evaporative emission test requirements. 

The 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, 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 standard levels presented in Table IV-18 are designed primarily to 

accommodate 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 normally allocate for vehicle certification. In the past 

manufacturers have employed techniques such as vehicle baking (discussed below) to 

accelerate the rate of this off-gassing, and until recently it has not been a major 

consideration for certification. 

In the past EPA has set relatively uniform (but not identical) evaporative emission 

standards for LDVs and LDTs and somewhat higher values for HDGVs. The proposed 

hot soak plus diurnal emission standards presented in Table IV-18 are somewhat higher 

as vehicles get larger in weight and physical size. This is because in general the vehicles 

have higher levels of non-fuel background emissions as they get larger. As mentioned 

above, the standards, which are approximately a 50 percent reduction from the existing 

hot soak plus diurnal standards, are intended primarily to accommodate non-fuel 

background emissions. Thus, the technology focus for the proposed Tier 3 evaporative 

emission standards is for vehicles to have essentially zero fuel vapor emissions.

 As described in more detail in Section IV.C.2 below, EPA is proposing a 

program that would allow manufacturers to demonstrate compliance with the proposed 

hot soak plus diurnal evaporative emission standards using averaging concepts. Under 

the proposal, manufacturers 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 proposed standards are discussed in 

Section IV.C.2. EPA is not proposing any changes to the existing light-duty running loss 

or refueling emission standards with the Tier 3 proposal, with the exception of the 

certification test fuel requirement.
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Table IV-18 Proposed Evaporative Emission Standards (g/test)a,b,c

Vehicle Category 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 proposed standards are the same for both tests; current 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

In addition to more stringent hot soak plus diurnal standards, EPA is proposing a 

new canister bleed emission test and standard as part of the Tier 3 program. The 

proposed bleed test procedure is described in Section IV.C.4.a., below. The purpose of 

the new test and standard is to ensure that near-zero fuel vapor emissions are being 

emitted by vehicles from the fuel tank through the evaporative emission canister. Under 

this proposal, manufacturers would be 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 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.2.g.ii

below. EPA is proposing not to apply 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 would need to 

demonstrate compliance with their respective standard. As discussed below, the canister 

bleed standard would not apply at high altitude. The canister bleed test and standard 

drives canister design elements such as total gasoline working capacity, internal 

architecture, and the type of carbon used. Since the performance of the canister is also 

evaluated in the hot soak plus diurnal evaporative emissions sealed housing for 

evaporative determination (SHED) test we are proposing that the canister bleed emission 

standard not be included in the In-Use Verification Program but it must be met in use. 

We would not expect to have canister bleed specific family criteria for certification but 

the test would have to be completed and the standard met for each evaporative/refueling 

family including potentially twice if there were two canisters used. A deterioration factor 

would not be required, but as mentioned above, the standard would have to be met in-use

and could be evaluated in EPA confirmatory testing. 

iii.Early and Transitional Hot Soak Plus Diurnal Standard

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-19. 
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Table IV-19 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 proposed 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 test of the vehicle fuel system (rig test) that from an engineering perspective 

is practically 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 no (< 54 mg) fuel vapor emissions. EPA 

is not proposing that Option 1 be part of the long term Tier 3 evaporative emission 

program. While we see the merit of the rig test as an engineering design and development 

tool for the manufacturers, by its very nature, the rig SHED standard is not 

implementable as an enforceable standard. We believe that the hot soak plus diurnal 

SHED test and the canister bleed test will accomplish the same objective of keeping fuel 

vapor emissions to a minimum. 

EPA believes most manufacturers will prefer to certify to the averaging based 

standards proposed by EPA (similar in stringency and program construct to CARB 

Option 2). However, because some manufacturers may have vehicle models meeting the 

CARB Option 1 standards and emission requirements now or in the near future, EPA is 

proposing that compliance with the CARB Option 1 standards would be an acceptable 

interim alternative to compliance with the proposed Tier 3 evaporative emission 

standards if the model is certified by CARB before the 2017 MY. EPA proposes that 

these vehicles could then be certified using carryover provisions through the 2019 MY.294 

As noted in the following sections, vehicles certified under this provision would count 

toward the phase-in percentage requirements and could earn allowances as discussed 

below, but the vehicles would not be eligible to earn or use credits for the evaporative 

 

294 EPA is proposing to incorporate by reference the CARB Option 1 test procedures and emission 

standards for this interim period. 
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emissions averaging program. Carryover vehicles would have to meet EPA leak 

emission standard to be counted toward the sales percentage requirements for 2018 and 

later model years.

b. 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 and IV.B of this proposal, along with the new emission standards, we are 

proposing 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 between 8,501 and 14,000 

lbs GVWR. The proposed longer useful life would also apply to certifications to the Tier 

3 evaporative emission requirements. For an evaporative/ refueling family certified to 

150,000 miles/15 year useful life for evaporative emissions this useful life would also 

apply to the refueling, leak, and high altitude standards, where applicable when a family

certifies to the Tier 3 evaporative emission requirements. 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, 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 would apply for all Tier3 evaporative emission 

standards including the hot soak plus diurnal emission standards, the refueling emission 

standard, and the leak standard because of the design and operating relationships between 

the engine, the fuel system, the evaporative control system and their various components. 

During the early and transitional program periods and until the final year of the 

allowed phase-in period for the Tier 3 evaporative emission program (MY 2015-2022) 

the differences between the proposed 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 but not necessarily to the Tier 3 evaporative emission 

requirements.295 In those situations, we are proposing 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. We also propose that during the 

phase-in period, if a family is certified to the Tier 3 evaporative emission requirements 

but not yet certified for Tier 3 exhaust emission requirements, then the useful life could 

 

295 By the 2020 MY, all Tier 3 evaporative system emissions certifications must use Tier 3 certification test 

fuel and test procedures. This affects evaporative (hot soak plus diurnal), canister bleed, refueling, and leak 

emission standards certification. 
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be 150,000 miles/15 years for evaporative and refueling emissions standards but the 

current useful life for exhaust emissions, However, by the 2022 MY EPA proposes that 

the useful life for all of these requirements would 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.296

OBD regulations call for the systems to operate effectively over the useful life of 

the vehicle. We are not proposing to change that requirement, but rather to clarify that 

during the early and transition years of the phase-in (MY 2015-2022), 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. 

2. Evaporative Emissions Program Structure and Implementation Flexibilities 

a. Percentage Phase-In Requirements

The proposed Tier 3 evaporative emission standards would be phased in over a 

period of six model years (MYs), including a transitional year in 2017. For MY 2017, 

except as discussed below, the requirement would apply to 40 percent of a 

manufacturer’s combined sales of LDVs, LDT1s, and LDT2s. To be consistent with the 

start date for new exhaust standards affecting these vehicles, the phase-in requirements 

would not include vehicles over 6,000 lbs GVWR until the 2018 MY. For the 2018-2019 

MYs, the requirement would apply to 60 percent of a manufacturer’s sales of all LDVs, 

LDTs, MDPVs, and HDGVs. This would increase to 80 percent for MYs 2020 and 2021 

and by MY 2022 it would apply to 100 percent of sales in these four categories. 

Beginning in MY 2018 any vehicle included in the percentage projection, except vehicles 

that had earned allowances would have to meet the leak emission standard.

Our proposal for MY 2017 has two options and we are seeking comment on a 

third option. The first, which we are calling the “percentage” option, would require that 

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 second which we are calling the 

“PZEV zero evap only” option, would require 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 vehicles in any state whose vehicles are 

covered by the Tier 3 evaporative emission standards. Thus, this would apply to sales in 

any state except for California and states that have adopted the CARB ZEV or LEV III 

 

296 The only exception here would be for vehicles not meeting Tier 3 evaporative emission requirements in 

the 2022 MY as a result of the use of previously earned allowances and small businesses which have until 

the 2022 MY to meet the proposed Tier 3 evaporative emission requirements..
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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 would 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 basic goal of the 2017 MY program is to provide evaporative emission 

reductions benefits in the other states which are similar to those expected in California 

and the states which adopted LEV III under section 177 of the Clean Air Act. Due to 

model phase-out and phase-in issues related to current and future products, some 

manufacturers have indicated that increasing production of Tier 3 evaporative emission 

compliant vehicles for the 2017 MY to meet the 40 percent value discussed above could 

be difficult and costly. To address this issue, we are asking for comment on a third 

option: decreasing this value from 40 percent to 20 percent but requiring that these same 

vehicles also meet the leak emission standard in the 2017 MY. This approach has the 

potential to address the transition issue and EPA believes that the leak standard will 

provide evaporative emission reduction benefits equal to or greater than the Tier 3 

evaporative emission standards. Thus, under this approach, the manufacturers’ product 

transition concerns could be addressed and the overall evaporative emission reductions 

would still be achieved for 2017 MY vehicles. As discussed below, beginning in the 

2018 MY, a Tier 3 compliant vehicle must also meet the leak emission standard. This 

option would be effective only in the 2017 MY. EPA asks for comment on whether this 

option should require the leak emission standard to apply to the same 20 percent of 

vehicles that are complying with the Tier 3 evaporative emission requirements, or 

whether this option should allow manufacturers the flexibility to meet some or all of the 

20 percent leak emission standard requirement with vehicles not yet compliant with the 

Tier 3 evaporative requirements. 

At the time of certification, manufacturers would identify which families would 

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 as well as vehicles meeting CARB’s Option 1 standards) and 

could also include earned allowances as discussed below. They would use projected 

sales information for these families plus allowances as desired and available, to show 

how they expect to meet the phase-in percentages for the model year of interest. At the 

end of the model year they would be expected to show that the percentages were met and 

if not they would either use additional allowances or bring more vehicle families into the 

calculation.

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 is necessary for determining compliance with the requirements of the 

standard. This is discussed in Sections IV.C.2.c.and d. As discussed further below, 

validated sales information would also be used for earning early allowances and to show 

compliance with the alternative phase-in schedule approach. 
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For these purposes, vehicles included in the phase-in percentage could be: (1) 

families which certified to CARB LEV III requirements in MYs 2015 and 2016 (CARB 

Option 1), (2) families certified to meet Tier 3 evaporative emission requirements, and 

(3) vehicles from the early allowance program. However, beginning in the 2017 MY, 

any new evaporative/refueling emission family certifications would have to meet the 

proposed EPA Tier 3 certification requirements for both test procedure and certification 

test fuel for the evaporative and refueling emission standards. The leak emission 

standard would apply in the 2018 MY. Furthermore, assuming other regulatory

provisions related to carryover of emissions data are met, 2015-2016 MY CARB 

evaporative emissions certifications could be carried over until the end of the 2019 MY 

and included as compliant vehicles within the program if they met the leak emission 

standard. 

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 proposed 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 16 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.

As a flexibility, we are proposing to allow 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. 

Under this approach, before the 2018 MY, manufacturers would have to present a plan to 

EPA which demonstrates that the sum of the product of a weighting factor and the 

percentages of their U.S. vehicle sales for each model year from 2018 through 2022 is 

greater than or equal to 1040. The 1040 value is equal to the sum of the product of the 

weighting factors and the percentage requirements for MYs 2018 through 2022, 

calculated in the following manner: [(5)(2018MY %)+4(2019MY %)+3(2020MY 

%)+2(2021MY %)+(1)(2022MY %)]. This would allow manufacturers to use a phase- in 

more consistent with product plans which may call for a lower percentage in 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 a different phase-in schedule for meeting 

Tier 3 exhaust and evaporative emission standards. As explained further below, any

allowances earned could be counted toward compliance with the 1040 value. Within this 

proposed flexibility EPA asks for comment in three areas. First, we seek comment on the 

need for and value of this alternative phase-in percentage flexibility option. Second, we 

did not include the 2017 MY in this flexibility because we believe that the PZEV zero 

evap nationwide option, the use of any earned allowances, and the ability to have a deficit 

in a given year are sufficient. However, we ask for comment on including the 2017 MY 

“percentage” option in this flexibility (both the 40 and 20 percent approaches discussed 

above). If after comment the 40 percent option from the 2017 MY is included in the 

final rule, the sum of the percentages would include an additional 240= (6)(40) for a total; 
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of 1280; the equation above would add a term of (6)(2017MY %). Similarly, we ask for 

comment on whether the 20 percent option from the 2017 MY should be included in the 

alternative phase-in approach. If it is included in the final rule, the sum of the 

percentages would include an additional 120= (6)(20) for a total; of 1160; the equation 

above would add a term of (6)(2017MY %). 

b. Early Allowance Program

We are proposing incentives for early introduction of vehicles compliant with the 

Tier 3 evaporative emission regulations. Manufacturers could 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.

As described below, manufacturers could earn “allowances” for selling any

vehicle certified to the proposed Tier 3 evaporative emission regulations earlier than 

required. The vehicles could be LDVs, LDTs, MDPVs, or HDGVs. Specifically these 

include the following: (1) for MYs 2015 and 2016, any LDVs and LDTs meeting the Tier 

3 evaporative emission regulations and sold outside of California and the states that have 

adopted CARB’s ZEV or LEV III programs, (2) for MYs 2015-2017, any MDPV or 

HDGV meeting the Tier 3 evaporative emission regulations early and sold in any state, 

(3) for MY 2017, any LDT3/4 meeting the Tier 3 evaporative emission regulations 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 HDGV between 10,001 and 14,000 lbs 

GVWR meeting the refueling emissions regulations and sold outside of California and 

the states that have adopted CARB’s LEV III or ZEV programs. 

In order to demonstrate compliance with the proposed Tier 3 evaporative 

emission regulations, the vehicles could be certified to either the proposed Tier 3 

evaporative emission standards or CARB’s PZEV zero evaporative emission and useful 

life requirements. Vehicles generating allowances would have to meet the proposed 

evaporative emission standards (CARB Option 1 or EPA Tier 3), the high altitude 

evaporative emission standard, the canister bleed standard as well as the refueling 

emission standards. Manufacturers would 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.

Allowances would be used in the compliance determination in the following 

manner. Vehicles qualifying for allowances could be used in the fleet average 

evaporative emission standard calculation for any year during the phase-in. This would 

apply to the primary phase-in and alternative phase-in programs. Allowance vehicles

would be entered into the compliance calculation with an emission value equivalent to 

the evaporative emission standard for their vehicle category from Table IV-18 even if it 

was certified to CARB Option 1 standards (Table IV-19). For the percent phase-in 

requirement in either the primary or alternative phase-in schemes, allowance vehicles 

would count for one vehicle for each allowance used within their vehicle category. For 

the primary scheme this would be counted as one vehicle, but for the alternative phase-in 
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option the value would be multiplied by the weighting factor (5 for 2018, 4 for 2019, 3 

for 2020, etc). Within the alternative phase-in scheme the manufacturer would 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 2018-2022). EPA believes this 

limitation is appropriate. 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 proposed allowances are designed 

primarily to facilitate manufacturer transition during the program phase-in. As such, we 

propose that they could not be traded between manufacturers and unused allowances 

would expire after the 2022 MY. 

An example here may be helpful in demonstrating how the proposed concept 

would work. Take a hypothetical manufacturer who earned 10,000 allowances in 2015 

and 2016 and sells 100,000 units per year. In 2018, the manufacturer would have a phasein 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. For the alternative phase-in 

scheme the proposed regulations would limit the use of allowances to 10 percentage 

points at the 60 percent. Without a multiplier this would require the use of all 10,000 

allowances in 2018, but with the proposed multiplier only 2,000 allowances would be 

needed to reach the 10 percentage point maximum. Using a similar calculus, the 

manufacturer could use another 10 percentage points in 2019, but it would require 2,500

allowances since the multiplier is 4. The number of allowances to reach 10 percentage 

points would increase each year as the multiplier decreased.

For the MY 2017, manufacturers choosing EPA’s proposed “percentage” option 

(see Section IV.C.2.a) could earn allowances for sales of LDT3s, LDT4s, MDPVs, and 

HDGVs that meet the proposed Tier 3 evaporative emission standards and other related 

requirements assuming their LDV, LDT1/2 sales meet the 40 percent requirement. 

Similarly, manufacturers choosing EPA’s proposed “PZEV zero evap only” option could 

earn allowances in MY 2017 for LDT3/4s, MDPVs, and HDGVs that meet the CARB 

Option 1 evaporative emission standards and related requirements. For both the 

“percentage” and “PZEV zero evap only” options for the 2017 model year, to avoid 

double counting, the allowances would be earned only for those vehicles sold outside of 

California and the states that have adopted CARB’s LEV III/ZEV program requirements. 

Vehicles earning allowances could either be vehicles certified to the Tier 3 evaporative 

emission standards or vehicles certified using carryover data from the CARB PZEV zero 

evaporative emission requirements from the 2015 or 2016 MYs. Since credits and 

allowances serve primarily the same purpose and allowing for splits of allowances/credits 

greatly complicates program implementation, we are proposing that manufacturers could 

only earn allowances in MYs 2015-2017 for any qualifying LDT3s, LDT4s, MDPVs, 

and HDGVs since these vehicles are not covered by the proposed Tier 3 standards until 

the 2018 MY. EPA asks for comment on whether this opportunity to earn allowances 

coupled with the aforementioned restriction on their use is the appropriate balance.
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c. Evaporative Emissions ABT

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 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. The average of all emissions for a particular manufacturer’s 

production within 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 is proposing an emissions ABT program for the Tier 3 hot soak plus diurnal 

evaporative emissions standards. This would be the EPA’s first averaging program for 

evaporative emissions from light-duty or heavy-duty vehicles. It would not apply to the 

high altitude standard, the canister bleed standard or the leak emission standard because it 

is the low altitude “zero evap” hot soak plus diurnal standard which will drive the 

fundamental technology used to comply with all of these requirements. EPA is proposing 

to include trading of emission credits between manufacturers, but in past similar 

programs there have been very few trades. Incorporating trading within the program adds 

a significant degree of complexity, so we are seeking comment on the need for and value 

of including trading.

The evaporative emissions ABT program would start with the 2017 MY for the 

percentage option. The programs would continue for the 2018 MY and beyond and 

would not sunset, as does the allowance program. Vehicles generating averaging/

banking credits in the 2017 MY or later would not be permitted to also generate 

allowances as this would be double counting. 
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A key element of an averaging program is the identification of the averaging sets. 

This sets the criteria for which emission families can be averaged for purposes of 

compliance as well as credit and deficit determinations. We are proposing four averaging 

sets and the applicable emission standard for each of the averaging sets as shown in Table 

IV-18. Except as noted in section d below, credit exchanges between averaging sets 

would not be permitted. Participation in averaging is voluntary since a manufacturer 

could elect to certify each family within the averaging set to its individual limit as if there 

was no averaging program. 

An evaporative emission ABT includes two very distinct steps. The first is the 

determination of the credit/deficit status of each family relative to its applicable standard 

from Table IV-18. The second is the role of ABT in the overall compliance 

demonstration which will be discussed in Section IV.C.2.d which follows.

A manufacturer choosing to participate in the evaporative emissions ABT 

program would certify each emission family to an FEL. The FEL selected by the 

manufacturer becomes the emission standard for that emission family. As noted below, 

emission credits (or deficits) are based on the difference between the emission standard 

that applies (by vehicle category) and the FEL. The vehicles would have to meet the FEL 

for all emission testing. 

We are proposing that the FELs selected by the manufacturer would have to be 

selected at 0.025 g/test increments above or below the applicable Tier 3 evaporative 

emission standards for each vehicle category. FELs could not 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 currently applicable under EPA’s 

regulations. The vehicle groupings for defining these FEL caps differ somewhat from the 

groupings that apply for the standards; we request comment on the need to reconcile 

these different groupings.

Evaporative emission credits under the proposed Tier 3 hot soak plus diurnal 

standards would be calculated differently in the 2017 model year and the 2018 and later 

model years. For 2017 calculations would 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 would be based on all 50 states. Calculations would 

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-18. The sales number used 

in the 2018 and later MY calculation would 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 
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evaporative emission standards.

297

 Emission credits banked under the proposed 

evaporative emission ABT program would have a five year credit life and would not be 

discounted. This means the credits would 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 would expire and could not be used 

by the manufacturer. We are proposing to limit 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 would have an FEL equivalent to the 

EPA emission standard (Table IV-18) for their respective vehicle category. 

 We request comment on all aspects of the ABT program. In particular, we 

request comment on the structure of the proposed evaporative emission ABT program 

and how the various provisions may affect manufacturers’ ability to utilize ABT to 

achieve the desired evaporative emission-reductions in the most efficient and economical 

way. We also ask for comment on basing ABT calculations on nationwide sales in 2018 

and later model years, even if there is a separate calculation for California and the section 

177 states. 

d. Compliance Demonstration

Demonstration of compliance with the evaporative emissions standards would be 

done after the end of each model year. There are two steps. In the first step, 

manufacturers would have to show compliance with the phase-in percentages whether 

they used the primary phase-in scheme or an alternative phase-in scheme. It is sales from 

these families together with their respective FELs which would be used to make the 

demonstration of compliance with the emission standard on average within each vehicle 

averaging set. Compliant vehicles types for these purposes would be the same as 

described in Section IV.C.2.a 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 the second step, using the family emission limits, 

manufacturers would calculate the sales-weighted average emission levels within each of 

the four vehicle categories using U.S. sales.298 Manufacturers would be 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 salesweighted calculated values would have to be at or below the emission standard for that 

vehicle category as proposed in Table IV-18, unless credits from ABT are used. If the 

difference between the standard and the sales-weighted average FEL is a positive value 

this could be a 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. Credit deficits would be allowed to be carried forward. However, manufacturers 

 

297 If EPA ultimately decided to continue the disaggregated approach to fleet compliance calculations, we 

could potentially base compliance with the proposed Tier 3 evaporative emission requirements on U.S. 

sales (i.e., non-California and non-section 177 states). 

298 The only exception here would 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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would be required to make up the deficit within the next three model years with credits 

from vehicles in the same averaging set except as described below. As discussed above, 

manufacturers would be required to identify and include in the calculations vehicle 

families from each and any covered category (see Table IV-18) whose total annual 

nationwide sales in the given model year equals or exceeds the prescribed percentages. 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. 

Allowances could 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 enters into the evaporative 

emissions ABT calculation as having an emission rate equivalent to the standard for that 

category of vehicle. Thus, allowance vehicles would help in demonstrating compliance 

with the percentage phase-in requirement (up to ten percentage points per model year) 

and would help in reducing deficits since their calculation value would be equivalent to 

the level of the standard. EPA asks for comment on whether allowances should be 

permitted to be used across vehicle categories during the transition years. 

 As was discussed above, during the 2017-2019 model years EPA is allowing 

manufacturers to meet the percentage phase-in requirements using carryover certification 

data from vehicles certified to CARBs Option 1 standards in the 2015 or 2016 model 

years. These vehicles may have CARB Option 1 certification values slightly higher than 

those proposed for EPA’s Tier 3 program for the given vehicle and vehicle category. 

Since the emission standard values in Tables IV-18 and IV-19 are very similar for any

given vehicle category, for purposes of simplification during the phase in, EPA proposes 

that any CARB Option 1 vehicles used in the 2017-2019 MY 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. 

Furthermore, we are proposing not allowing manufacturers to generate emission credits 

for families certified with EPA based on carryover CARB PZEV evaporative emissions 

data using CARB Option 1 as in Table IV-19. We are proposing not to include 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 

offerings, allows for a different number of PZEV sales as a function of manufacturer size.

 As mentioned above, we are proposing to limit use of credits only within a 

defined averaging set. Cost effective technology is available to meet the proposed hot 

soak plus diurnal emission standards on average within each of the vehicle categories in 

the averaging sets, especially since the proposed standards are designed to accommodate 

nonfuel hydrocarbon background emissions. Thus, further flexibility is not needed. 

Moreover, we are proposing to constrain averaging to within these sets because of equity 

issues for the manufacturers. We are concerned that 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 
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product lines. This effect could be even more pronounced if the number of evaporative 

families was considered, since larger more diverse manufacturers have more models and 

thus more evaporative families. EPA asks for comment on issues related to averaging 

sets. 

Manufacturer use of credits from different averaging sets to demonstrate 

compliance would be 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 would have to use 

credits from the same averaging set during the next three years to make up the deficit. 

However, if a deficit still exists at the end of the third year, we propose that the 

manufacturer could use credits from a different averaging set to cover the remaining 

deficit with the following limitations. Manufacturers would be able to use credits from 

the LDV and LDT1 averaging set to address remaining deficits in the LDT2 averaging 

set, and vice versa. We also are proposing that manufacturers be 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 would be allowed. These restrictions are being proposed because of equity

concerns caused by the different nature and size of various manufacturer product lines. 

During the program phase in there will be a declining percentage of vehicles not 

yet covered by the proposed Tier 3 evaporative emission requirements and thus covered 

by the current EPA requirements in 40 CFR 86.1811-09 and 86.008-10. These vehicles 

would need to be certified to current EPA requirements or seek EPA certificates based on 

LEV II or LEVIII emission data, subject to the certification fuel requirements discussed 

below.

For both the percentage phase-in and sales-weighted average calculation steps 

above, we are proposing to base the calculation on nationwide sales (excluding California 

and the section 177 states in the 2017 MY) and 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 would enable a nationwide program has been an 

important premise of this proposal. 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 manufacturers 

on a national fleet versus a bifurcated approach such as exists today (California and 

section 177-states separate from the rest of U.S. sales) have not yet been made.299 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. However, for evaporative emissions for the 

 

299 If the decision is ultimately made to continue the disaggregated approach to fleet compliance 

calculations, the compliance with the proposed Tier 3 requirements would be based on U.S. sales (nonCalifornia, non-section 177 states).
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2017 MY we are proposing that percentage phase-in and sales be done on a disaggregated 

level (i.e., California and section 177 states and the remainder of the country) since at the 

present time the anti-backsliding provisions of the LEV III evaporative emissions

program stays in place through the 2017 MY. This is being done differently for the 

calculations for the early allowance program because these “zero evap” vehicles are 

already counted in the pre-existing ARB program.

As was discussed above, manufacturers not meeting the percentage phase-in 

requirements would 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. Resolving this sales percentage shortfall problem becomes 

a bit more complicated for the 2017 MY 20 percent option upon which EPA is seeking 

comment, because it would require that 20 percent of vehicles meet the proposed Tier 3 

evaporative emission requirements and that 20 percent meet the proposed leak emission 

standard. These may or may not be the same vehicles, (e.g., non-Tier 3 vehicles could 

end up in the end of year calculation and we are seeking comment on whether to allow 

the two 20 percent requirements to be allowed to be met on different vehicles). As a 

means to resolve this potential problem, EPA asks comment on a provision which would 

require that any shortfall of either of the 20 percent values (Tier 3 evaporative or leak

emission standard) for the 2017 MY be covered 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 were 5 percentage points short in the 2017 MY, then it would 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.).

e. Small Volume Manufacturers 

As another flexibility, we are proposing that small volume manufacturers, those 

with average annual nationwide sales of 5,000 units or less, be permitted to delay meeting 

the proposed Tier 3 evaporative emission standards, including the requirement to use 

EPA certification test fuel, until the 2022 MY (see Section IV.E.5 below for a discussion 

of our proposed 5,000 vehicle threshold). This would include the hot soak plus diurnal 

standards, the canister bleed emission standard, and the leak emission standard. In the 

interim, these vehicles would have to meet the current evaporative and refueling emission 

standards. The initial determination of whether a manufacturer is under the 5,000 unit 

threshold would 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 exceeded 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 exceeded 5,000 units per year in any three consecutive 

model years they would have to meet the Tier 3 evaporative requirements in the third 

model year thereafter. For example, if a new market entrant in 2015 projected 

nationwide production of 4,000 units per year and the average of actual values in 2015-
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2017 exceeded 5,000 units per year they would have to meet Tier 3 evaporative 

requirements by the 2020 MY. 

f. High-Altitude Requirements

We adopted the most recent vehicle evaporative emission standards in 2007.300 

These newest standards apply only to testing under low-altitude conditions.301 In that 

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. This was intended to account 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 and vapor concentrations in air. 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 EPA 2-day low altitude evaporative emission standards and requirements for 

high-altitude testing. The vehicle categories for the high altitude standards in this 

proposed rule are the same as for the low altitude standards. The proposed standards are 

presented below in Table IV-20. This would both reduce 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. 

Furthermore, the leak emission standard proposed in Section IV.C.5.b below would apply

equally at low and high altitude testing.

Table IV-20 Proposed 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

A few additional points should be noted about our proposed Tier 3 high altitude 

evaporative emissions control program. First, by proposing to apply the current low 

 

300 72 FR 8428 (February 26, 2007).

301 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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altitude evaporative emission standards and requirements by category for high-altitude, 

we are proposing not to include the canister bleed test and emission standard. These 

vehicles would have to meet the canister bleed emission standard at low altitude and 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

and increase the testing burden, but not necessarily lead to more emissions control. 

Therefore, we believe the low-altitude canister bleed test is sufficient for achieving the 

proposed level of emission control for operation in both low-altitude and high-altitude 

conditions. Second, for vehicles certified with FELs above or below the applicable 

standard for testing at low altitude, we propose that the same differential 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 would be 0.75 g (0.65g+0.10g). 

This high-altitude FEL would not be used for any emission-credit calculations, but it 

would be used as the emission standard for compliance purposes. Third, gasoline RVP 

for certification test fuel would be set at 7.8 RVP with 15 percent ethanol, as specified in 

Section IV.D. Finally, we are proposing a minor adjustment to the high altitude test 

procedures. Today, the 2- and 3-day test procedures apply equally at low and high 

altitude. We are proposing to keep that requirement but to allow for an adjustment of 5 °F 

in the temperatures related to the running loss test within the 3-day test cycle. Thus, the 

applicable fuel and ambient temperatures at §86.134-96 (f) and (g) would 90±5 °F instead 

of 95±5 °F for high altitude testing. 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. We request comment on 

the alternative approach of keeping test temperatures the same, but omitting the 3-day test 

cycle for testing at high altitude. This would effectively establish the 2-day test cycle as 

a sufficient means of demonstrating that emission control systems continue to operate 

properly at high altitude.

As mentioned above, emission data from vehicles meeting the current CARB zero 

evap and useful life requirements could be used to qualify that vehicle to meet the Tier 3 

evaporative emission regulations for the 2017-2019 MYs. To qualify for a federal 

certificate, the vehicle would also have to meet the Tier 3 high altitude evaporative 

emission requirements. While CARB requires vehicles to meet EPA high altitude 

requirements, we ask for comment on the need for and value of an interim option which 

would permit manufacturers to gain such certification by an engineering demonstration 

that the vehicle would comply at any altitude rather than by performing additional testing. 

g. Technological Feasibility

The basic technology for controlling evaporative emissions was first introduced in 

the 1970s. Manufacturers routed fuel tank and carburetor vapors to a canister filled with 

activated carbon, where vapors were stored until engine operation allowed for purge air 

to be drawn through the canister to extract the vapors for delivery to the engine intake. 

Over the past 30 years, evaporative emission standards have changed several times, most 

notably in the mid-1990s when enhanced evaporative controls were required to address 2-

and 3- day diurnal emissions and running losses. Refueling emission controls were added 

with phase-in beginning in the 1998 MY. Almost universally manufacturers elected to 
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integrate evaporative and refueling emission control systems. In the mid-2000s more 

stringent evaporative emission standards with E10 durability gasoline led to the 

development and adoption of technology to identify and eliminate permeation of fuel 

through fuel tanks, fuel lines, and other fuel-system components. 

i. Hot Soak Plus Diurnal 

The current baseline technology for LDVs, LDTs, and MDPVs is a properly 

designed and assembled fuel/evaporative system for controlling emissions over the 2-and 

3-day test sequences to meet the current standard of 0.650 grams/test. This involves 

activated carbon canisters which capture gasoline vapors, with engine calibrations 

designed to maximize canister purge over the test sequence. Fuel systems generally 

include widespread use of various grades of permeation-resistant materials.

 The anticipated control technologies to comply with the proposed hot soak plus 

diurnal evaporative emission standards include an improved carbon canister designs to 

even better capture vapor emissions from the canister, air intake designs to prevent the 

escape of unburned fuel from the engine’s crankcase, various upgrades to further limit 

potential micro-sized leaks, and further steps to reduce permeation rates. Applying these 

new or improved technologies will allow manufacturers to meet the proposed 300 mg 

standard for LDVs/LDT1s. The proposed evaporative emission standards are slightly 

higher for larger vehicles to account for potentially higher background emissions and in 

some cases larger surface area components, but the baseline and anticipated control 

technologies follow a very similar path. These baseline and control technologies are 

described further in the rest of this section.

Current evaporative canisters use high working-capacity activated carbon, usually

with multiple compartments, to optimize vapor loading and purging behavior. These 

canisters sometimes employ carbons of different working capacities within each 

chamber. Testing indicates that the total canister adsorption capacity in grams of 

gasoline vapor is generally dictated by the requirements of the refueling emission test and 

standard rather than the evaporative emission test (either the 2- or 3-day sequence). 

Manufacturers have identified the engine’s intake system as another source of 

evaporative emissions. These result from crankcase vapors and from unburned fuel from 

injectors, or sometimes from an injection event that occurred shortly before engine 

shutdown. We estimate a typical emission rate of about 40 mg associated with each 

engine shutdown event; however, since the actual emission rates depend on timing of 

individual injection events and cylinder position at shutdown, baseline emission rates can 

vary significantly. These vapors must follow a contorted path before reaching the 

ambient air, which would generally cause these emissions to show up during the first day

of the diurnal test rather than the hot soak test. One way to prevent these emissions is to 

add activated carbon to the air intake downstream of the air filter, typically in the form of 

reticulated foam coated with activated carbon. This device would have only a few grams 

of working capacity and would be designed to purge easily to ensure that the vapor 

storage is available at engine shutdown. This carbon insert would almost completely

eliminate any vapor emissions from the air intake system.
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Manufacturers wanting to avoid adding any specialized emission control 

component to control evaporative emissions from the air intake could pursue alternative 

approaches. First, it is possible to allow the engine to continue rotating for 2-3 

revolutions after engine shutdown to sweep any hydrocarbon vapors from the intake 

system into or through the cylinder. These vapors could be burned in the cylinder, 

oxidized at the catalyst, or stored until the engine starts again. This may still allow for a 

small amount of residual vapor release, but this should be a very small quantity. Vehicle 

owners would be unlikely to notice this amount of engine operation after shutdown. 

Second, to the extent that manufacturers use direct injection, there should be no fuel 

vapor coming from the intake system. Any unburned fuel coming from the injectors 

would be preserved in the cylinder or released to the exhaust system and the catalyst. A 

small amount of crankcase vapor might remain, but this would likely not be enough to 

justify adding carbon to the intake system.

Fuel tanks are designed to limit permeation emissions. Fuel tanks are typically 

made of high-density polyethylene with an embedded barrier layer of ethyl vinyl alcohol 

(EvOH) representing about 1.8 percent of the average wall thickness. The EvOH layer is 

effective for reducing permeation emissions. Recent developments in production 

processes have led to improved barrier coverage around the ends of the tank where the 

molded plastic is pinch-welded to form a closed vessel. We are expecting manufacturers 

to increase the EvOH barrier thickness to about 3 percent of the average wall thickness to 

provide a more uniform barrier layer, to provide better protection with ethanol-based 

fuels, and to improve permeation resistance generally. These changes are expected to 

decrease emission rates over the diurnal test from about 40 mg per day to 15 mg per day

from the fuel tank assembly or less.

Fuel lines are also already designed for low permeation rates. The biggest portion 

of fuel and vapor lines are made of metal, but that may still leave several feet of nonmetal 

fuel line. There may be development of new materials to further reduce permeation rates, 

but it is more likely that manufacturers will adjust the mix of existing types of plastic fuel 

lines to achieve the desired performance at the lowest possible price.

The bigger area of expected development with respect to fuel lines is to reengineer fuel systems to further reduce the number of connections between fuel-system 

components and other fuel-line segments. Today these systems may involve more than 

the optimum number of connections and segments due to assembly and production 

considerations or other factors. Designing the fuel system more carefully to minimize 

connection points will limit possible paths for fuel vapors to escape. This would reduce 

emission rates and it should also improve system durability by eliminating potential 

failure points. A broader approach to addressing this source of emissions is to integrate 

designs and to move fuel-system components inside the fuel tank, which eliminates the 

concern for vapor emissions and permeation from those components and connections.

A remaining area of potential evaporative emissions is the connection between the 

fill neck and the fuel tank. Manufacturers can reduce emissions by perhaps 10 mg per 

day by making this connection permeation-resistant. The challenge is to design a lowcost solution that is easily assembled and works for the demanding performance needs 
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related to stiffness/flexibility. The best approach is likely either to use mating parts made 

from low-permeation materials, or to use conventional materials but cover this joint with 

material that acts as a barrier layer.

Purge rates are currently designed to flow relatively large volumes of outside air 

through the canister when the purge solenoid is activated. This involves using available 

manifold vacuum to create purge flow, with limits in place to avoid drawing too much 

unmetered fuel vapor from the canister. Tightening the evaporative emission standard 

would lead manufacturers to address remaining emission sources from micro-size leak 

points, permeation, and diffusion, as noted above. Since the amount of additional vapor 

being captured by the carbon canister is small and the test procedure is not changing, we 

do not expect the change in standards to drive changes in purge strategy, rates, or canister 

capacity. Nonetheless, vehicle system and engine changes to improve fuel economy 

could impact future purge strategies. Thus, as part of this approach, manufacturers may

incorporate designs to reduce vapor volume/mass directed to the canister and thus 

potentially reduce the purge air volume requirements. In addition, canister designs can 

be optimized to increase the effectiveness of a given volume of purge air. This could 

involve selecting different combinations of carbon characteristics and canister 

architecture types and by adding features to add heat (or preserve heat) in the canister 

during a purge event. It is also possible that fuel economy strategies which impact purge 

volume may lead some manufacturers to add vacuum pumps to supplement engine-based 

purge on some vehicle models in the future.

It is worth noting that there may be some models where manufacturers 

incorporate hardware or another control technique that may not be widely used across by 

all manufacturers or across all models. This is especially true for this set of proposed 

emission control requirements since we are considering such a wide array of basic 

vehicle and engine designs. Also, future vehicle/engine systems such as hybrids may

have more unique challenges in areas such as the diurnal fuel tank vapor load sent to the 

activated carbon canister and subsequent purging of those vapors. In response to this 

challenge, manufacturers may employ techniques to reduce fuel tank vapor generation 

and/or to enhance purge efficiency. Hardware such as a vapor blocking valve or other 

techniques to enhance purge efficiency from the canister through heating may be 

employed to a limited degree.

 The technologies discussed above are in use to varying degrees on many of the 

CARB PZEV zero evap vehicles mentioned above. Taken together, we believe these 

technologies provide manufacturers with effective tools for reducing emissions 

sufficiently to meet the proposed evaporative emission standards.

ii. Canister Bleed Emission Standard

More stringent evaporative emission standards have led to more careful 

measurements, which led manufacturers to discover that 80 mg or more of fuel vapor 

would 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, and the size and architecture of the canister and the 
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characteristics of the carbon itself. While the biggest effect of this vapor distribution is a 

uniform concentration within the canister, it can also cause vapors to escape through the 

canister vent even without continued canister loading that would result from fuel tank 

heating. These are referred to as canister bleed emissions. These emissions occur to 

some degree during the 2- and 3-day evaporative emissions test, but a separate standard is 

needed if the goal of near zero fuel vapor emissions is to be achieved. 

The design to address this concern is a supplemental “scrubber” canister (or

canister compartment) with a very low working capacity carbon. Adding 100 or 200 ml 

of this type of carbon near the canister vent provides a margin of “reserve capacity” to 

capture diffusion losses from the canister. Since this extra carbon has low working 

capacity and it purges readily, it is typically cleared of hydrocarbon vapors and ready to 

perform its function after any amount of engine operation or even with natural back purge 

which occurs when the fuel in the tank cools. This scrubber element is expected to 

eliminate all but 5-10 mg of emissions from the evaporative canister over the 

measurement procedure. 

iii.Leak Emission Standard

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. Because these emissions from these areas would occur in 

the 2-3 day evaporative emissions test if the problems were present, manufacturers have 

taken steps to address these potential problem areas as part of their overall evaporative 

emissions control strategy. Since the 2- and 3-day hot soak plus diurnal standards are 

proposed to become more stringent and leak emissions occur during the evaporative 

emissions test, we expect manufacturers to take the measures described above in Section 

IV.C.2.g.i. These include reducing connections, improving the quality of fuel and vapor 

line connections, use of improved component materials and revised installation practices. 

Manufacturers could also review their OBD leak warranty data and related information 

from OBD queries to help inform their strategies. One of the key reasons for proposing a 

leak emission standard is to promote the continuing development of designs, part 

production techniques, and assembly practices which will yield less in-use emissions 

deterioration and improved in-use emissions performance. EPA believes this focus on inuse durability is important because a vehicle with even a small leak, e.g., the size of the 

0.020-0.040 inch orifice diameter monitored by OBD systems would likely emit above 

the proposed hot soak plus diurnal evaporative emission standard in use. 

3. Heavy-Duty Gasoline Vehicle (HDGV) Requirements 

a. Overview of the Proposal for HDGVs

As presented above, EPA is proposing to include HDGVs within the Tier 3 

evaporative emissions program. The proposed hot soak plus diurnal and canister bleed 

test emission standards that would apply to these HDGVs are as presented in Table IV-18

and the high altitude standard is presented in Table IV-20. These vehicles would be 
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included in the averaging calculation beginning in the 2018 MY and would be eligible for 

creating and using allowances and credits as discussed above. Furthermore, for the 

reasons discussed below, EPA is proposing that HDGVs equal to or less than 14,000 lbs 

GVWR be required to meet the refueling emission standard by the 2018 MY. 

b. Background on the HDGV Sector 

HDGVs are generally 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.302 HDGVs are predominantly but not exclusively

commercial vehicles, mostly trucks and other work type vehicles built on truck chassis. 

EPA often discusses HDGVs in three basic categories for regulatory purposes according 

to their GVWR class. These include 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 sub-categorized into complete and incomplete vehicles.303 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 

vehicle is certified as a chassis for evaporative emissions while the engine is 

dynamometer certified for exhaust emissions.

For LDVs and LDTs, the current EPA evaporative and refueling emission test 

procedures are the same for all vehicle categories and the emission standards are of a 

similar but not always identical stringency, within the subclasses. However, this is not 

true for HDGVs. For HDGVs, the level of the evaporative emission standards and the 

test procedures vary by category and the refueling emission control requirements are also 

different. There are several reasons for these differences, including variations in the size, 

design, and other properties of the basic fuel system, the dimensions of the vehicles, and 

the potential for actions of secondary manufacturers to impact the fuel system. There are 

many fuel system similarities between Class 2b/3 HDGVs and heavy LDTs, but fewer 

similarities between heavy LDTs and HDGVs in Class 4 and above.

 

302 MDPVs also meet the definition of HDVs, but they are classified separately for evaporative and 

refueling emission purposes. See 40 CFR 86.1803-01.

303 Vehicles may be complete or incomplete vehicles. 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) attached when it is first sold. This may include vehicles sold to secondary vehicle 

manufacturers.
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Over the past 15 to 20 years, there have been several notable changes in HDGV 

products and market that have influenced the application of evaporative and refueling 

emission control requirements and may impact potential new or revised requirements 

going forward. Most noteworthy among these are the increased use of diesel engines 

across all weight classes and the emergence of better defined market segments for 

primary OEMs and secondary manufacturers.

The increased use of diesel engines has reduced overall HDGV sales and brought 

about a consolidation of manufacturer HDGV product offerings. For Class 2b/3 HDGVs, 

these are now all derived from LDT chassis and have the same basic fuel system and 

engine characteristics. This has led EPA to extend the light-duty evaporative and 

refueling test procedures and emission standards to the Class 2b/3 HDGVs, when 

applicable. In a rule promulgated in 2000, EPA required manufacturers to certify these 

HDGVs using light-duty test procedures. Also, in this same rule, EPA extended the 

vehicle refueling emission standards to complete Class 2b vehicles. These actions were 

technically appropriate because of the similarities between the LDT and Class 2b HDGVs 

and fuel systems and the large fraction of complete Class 2b HDGVs produced by the 

vehicle manufacturers. Today, fuel systems for Class 3 HDGVs are comparable those for 

Class 2b HDGVs, so it is reasonable and technically feasible to extend the Class 2b 

refueling emission requirements to Class 3 HDGVs.

Class 4 and heavier HDGVs still play a small but important role in the traditional 

truck and heavy-duty vehicle markets. These vehicles are sometimes distinctly different 

from Class 2b/3 vehicles in terms of testing, chassis designs, and fuel system 

characteristics; secondary manufacturers also play a larger role in the overall completion 

of the vehicle. For these vehicles, the engines are certified for emissions on an engine 

dynamometer while the evaporative emissions are certified separately on the vehicle 

chassis. Furthermore, these vehicles are larger dimensionally (which often means longer 

fuel and vapor lines) and have larger volume fuel tanks (sometimes two), which may be 

mounted on the underbody or side-rail. It is common for a secondary manufacturer to 

complete the vehicle by adding the cargo container or other working equipment box or 

package (e.g., small cargo truck or tow truck) and in some cases to reconfigure 

components. While the extrapolation of refueling emission control technology is 

conceptually straightforward, in some cases there may be unique technical issues related 

to implementing refueling emission controls for these heavier HDGVs relative to Class 

2b/3 HDGVs and LDTs.

Based on these considerations, EPA is proposing that the refueling emission 

standards in §86.1816-05 to apply to Class 3 HDGVs as well. This is appropriate 

because the fuel and evaporative control systems on these vehicles are very similar to 

those on their slightly lighter-weight Class 2b counterparts, and in some cases Class 3 

HDGVs are already designed to meet this proposed requirement. EPA is proposing that 

this requirement be met beginning in the 2018 MY. EPA is also proposing that 

manufacturers be permitted to comply 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 under the Tier 3 evaporative emission program. EPA 

believes this is appropriate since the expected daily average reduction in vehicle refueling 
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emissions for this class of vehicles is large relative to the reduction in evaporative 

emissions expected under Tier 3. Any certifications, including those done early, must use 

EPA Tier 3 test procedures and certification test fuels.

c. Other Potential Program Elements for HDGVs

EPA is seeking comments on several other programmatic elements related to the 

Tier 3 evaporative and refueling emission control proposal. 

First, even if we do not revise the current evaporative emission standards for these 

vehicles and they are not required to control refueling emissions, we are seeking 

comment on requiring manufacturers to certify their evaporative emissions using Tier 3 

certification test fuel. Tier 3 certification test fuel would provide equivalent or better 

emissions control as compared to current certification test fuel in terms of the fuel quality 

impact on emission control system designs to meet the existing evaporative emission 

standards and would provide equivalent or better in-use performance. Requiring this new 

certification test fuel has the potential to add efficiency to the certification process since 

manufacturers could certify one system for EPA and CARB for each evaporative family. 

Since incomplete vehicles and those over 14,000 lbs GVWR often do not use the same 

test vehicle/engine for evaporative and exhaust emission testing, we seek comment on 

whether a requirement for vehicle evaporative and/or refueling emission certification on 

Tier 3 test fuel would technically necessitate engine exhaust emission certification on 

Tier 3 test fuel.

Second, as mentioned in Section IV. B., EPA is also seeking comment on 

requiring the use of Tier 3 certification test fuel for HDGVs which are enginedynamometer certified, not chassis-certified, for exhaust emissions. This would 

potentially include all engine families certified for use in HDGVs above 8,500 lbs. 

GVWR. We are seeking comment on this change because we believe it may be the best 

and most representative technical approach for the future in the context of the 

engine/emission control system/fuel system design and performance and fuel quality. 

Overall, we believe this change to the certification test fuel for HDGVs would provide 

equivalent or better emissions control for the regulated pollutants as compared to current 

certification test fuel, in terms of the impact of fuel quality on emission control system 

designs and in-use performance, and may also simplify manufacturers’ testing operations 

by providing for a single test fuel. We are also seeking comment on putting this 

requirement in place in the 2020-2022 MY time frame. Consistent with the approach 

proposed in Section IV.D.4 for light- and heavy-duty vehicles, we are committed to the 

principle of ensuring that any change in test fuel for heavy-duty engines would not affect 

the stringency of either the fuel consumption or GHG emissions standards. As part of the 

separate rulemaking discussed in Section IV.D.4, we would 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 
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proposing to permit evaporative emissions certification by engineering analysis for 

vehicles above 14,000 lbs GVWR (instead of above 26,000 lbs GVWR as is permitted in 

the current regulations). These HDGVs would remain subject to the emission standards 

when tested using the specified procedures. This is the same cut point allowed by CARB 

and would allow for one certification method. Furthermore, for HDGVs over 14,000 lbs 

GVWR, we request comment on taking an additional step to rely even further on design 

parameters and engineering analysis. Under this approach, manufacturers would need to 

demonstrate that the design of their purge strategy, canister capacity, and overall control 

system would control emissions to the same degree as similar (or comparable) Class 2b 

or Class 3 vehicles that meet emission standards when tested over the established 

measurement procedures. The standard would be a performance standard in that the 

manufacturer could use any design that met the criteria of controlling emissions to the 

same degree that occurs in vehicles that meet the emissions standard. However, unlike 

the proposed approach, compliance with the standard would be based solely on an 

engineering review of the design. Compliance would not be determined by measuring 

performance on the emissions test. This would take into account the limitations in 

managing any significant degree of testing with these over-size vehicles. In particular, 

we request comment on the enforceability of taking the approach of a design standard.

Fourth, we are proposing 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 heavy-duty gasoline engines.

Fifth, we also seek comment on the implications on these evaporative emission 

standards were we to require the certification test fuel to be 10 psi RVP E10 as discussed 

below in Section IV.D.1.

 Sixth, we are proposing to clarify how evaporative emission standards affect 

engine manufacturers and proposing more descriptive provisions related to certifying 

vehicles above 26,000 lbs GVWR using engineering analysis. These improved 

descriptive provisions would apply to vehicles above 14,000 GVWR lbs if the proposed 

change in GVWR cut point for engineering analysis certification is finalized.

Finally, EPA is asking for comment on several other provisions related to the 

heavier HDGVs (over 14,000 lbs GVWR). First, if we do not include these heavier 

HDGVs in the Tier 3 final rule requirements, we are asking comment on whether 

manufacturers should be able to voluntarily certify any HDGVs not covered by the rule to 

the same requirements as being proposed for Class 2b/3 HDGVs, and through this action 

earn allowances and credits for use within the Tier 3 program as discussed above for 

other vehicles. This would include both evaporative and refueling emissions standards. 

Second, EPA also asks comment on whether there should be a provision to permit 

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 would expect these HDGVs to meet 

all the requirements applicable to the group in which they are being included (e.g., useful 

life, OBD, etc.). 
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4. Test Procedures and Certification Test Fuel

a. Review and Update of Testing Requirements

EPA adopted the current test requirements for controlling evaporative emissions 

in 1993.304 Those changes included: (1) diurnal testing based on heating and cooling the 

ambient air in the SHED305 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 “two-diurnal sequence” involves canister loading to 

two-gram breakthrough, followed by driving for the exhaust test (about 31 minutes), a 

hot soak test, and two days of cycled ambient temperatures. The “three-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 was 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).306 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 

has become clear that ORVR testing with these integrated systems serves as the 

benchmark for achieving adequate canister storage capacity. 

 

304 58 FR 16002 (March 24, 1993).

305 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.

306 59 FR 16262 (April 6, 1994). 
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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 

proposing to change the test procedures for demonstrating compliance with the proposed 

Tier 3 emission standards.

As described above, we are proposing to adopt a new standard based on measured 

values over a “canister bleed test,” which is intended to measure only fuel vapors which 

diffuse from the evaporative canister. CARB developed this procedure as a means of 

setting a standard that would not be affected by nonfuel background emissions. This 

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), either using a conventional SHED approach or 

by collecting emissions in a bag and measuring the mass. Rather than repeating CARB’s 

regulations, we are proposing to incorporate those regulations by reference into the CFR. 

This will avoid the possibility of complications related to minor differences that may

occur with separate test procedures.

CARB also adopted a 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 proposed EPA requirements which 

include the canister bleed test and emission standard instead of CARB Option 1 which 

includes the rig test and emission standard. However, since we are proposing to accept 

CARB Option 1 certifications for the 2017 through 2019 model years, we are also 

proposing to incorporate by reference CARB’s rig test into the CFR to accommodate 

those manufacturers that do in fact rely on this approach.

Also, as discussed further below, we are proposing to adopt a new leak test 

procedure which would be used to measure leak rates for the proposed leak emission 

standard. The leak test standard test procedure is contained in the proposed regulatory

text. Further detail can be found in the draft Regulatory Impact Analysis (Appendix to 

Chapter 1).

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 
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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.

We request 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. 

b. Test Fuel

EPA is proposing to change the certification test fuel specifications as described 

in Section IV.D. Here we discuss some implications for evaporative and refueling 

emissions testing. We are proposing to revise the certification test fuel specification 

(including durability fuel) in conjunction with the proposed 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. Any Tier 3 evaporative emission certification would have to 

use Tier 3 certification test fuel and test procedures. This could be done as early as the 

2015 MY and would be required for all vehicle models by the 2020 MY. We are further 

proposing to apply 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 proposed Tier 3 evaporative emission standards, they would 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), refueling, canister 

bleed, and high altitude testing requirements and emission standards. We are also 

proposing that any family that is not yet captured within the Tier 3 phase-in percentage 

may remain on current certification fuel or, as discussed below, California certification 

test fuel and test procedures through the 2019 MY. By the 2020 MY all evaporative and 

refueling emission certifications would have to be on EPA test procedures and 

certification fuels. It is useful to clarify that any confirmatory or in-use testing for these 

families would be done on the fuel on which they were originally certified. However, by

the 2020 MY all vehicles must be certified with Tier 3 certification test fuel and that test 

fuel would have to be used in confirmatory and in-use testing.

Finally, we are proposing that any vehicle certified to the refueling spit back 

standard separately (mostly incomplete HDGVs) may continue to do so using current 

certification fuel until the 2022 MY even if it’s evaporative and/or refueling emissions 
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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. 

 There are two main fuel properties that influence evaporative emissions: ethanol 

content and vapor pressure. Current requirements specify an emission test fuel with no 

ethanol for emissions testing; however, the current regulation specifies that 

manufacturers must perform service accumulation (durability) using fuel with, at a 

minimum, the highest concentration of ethanol permissible under federal law for in-use 

gasoline and that is commercially available in at least one state. In this case, this 

provision has the effect of insuring that manufacturers would design their fuel systems to 

account for the effect of ethanol on permeation emissions. Even without ethanol in the 

test fuel, the extended operation with gasoline-ethanol blends for service accumulation 

would effectively force the manufacturers to design systems which effectively control 

emissions from the blended fuel. By regulation manufacturers must use a 10 percent 

ethanol fuel in current evaporative emissions durability work. As a result, adding ethanol 

to the test fuel for Tier 3 evaporative and refueling emission testing should pose no new 

or greater challenge for manufacturers. A second 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 adsorb onto and desorb from the activated carbon in the 

canister. We are proposing to address this issue by the use of a prescribed scaling 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 suggest that a scaling value of approximately 1.1 would be 

appropriate for E15.308 This means that the value measured in the SHED would be 

multiplied by 1.10 to account for a difference in the FID response. This was determined 

using data which indicates that from a near worst case perspective the term within the 

bracket { } below equals 1.1. 

MHC adj = [(PBVn/T) (.000297)(ppmCfid)*{1+((1-ra) (reth))/ 1+((reth)(ra))}]

This adjustment would apply to hot soak plus diurnal, refueling, canister bleed, 

and spitback emission standards testing. For higher ethanol blends (such as E85), the 

regulation already specifies measurement and calculation procedures to adjust for this 

effect. We are not proposing any changes to these procedures.

 

308

 Moulis, C. (2012, January). SHED FID Responses for Ethanol. Memorandum to the docket. 
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c. Vehicle Preconditioning for Nonfuel Hydrocarbon Emissions for the Tier 3 

Evaporative Emission Standards

The proposed 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 canister bleed and leak emission 

standards are not influenced by non fuel hydrocarbon emissions from the vehicle. 

Nonfuel hydrocarbon emissions from the vehicle are measured as part of SHED emission 

testing, and are indistinguishable for 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 often 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 proposed 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 may be warranted. 

Providing some recognition of and allowance for this practice would 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 proposed 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 of vehicle background level might be the level which would 

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.
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We are not proposing to specify standardized preconditioning practices or 

protocols with regard to addressing nonfuel hydrocarbon emissions before evaporative 

emission certification testing. However, we are proposing general provisions in four 

areas. First, we would specify in the regulations that preconditioning for the purpose of 

addressing nonfuel hydrocarbon emissions is permitted. Second, we would specify that 

any preconditioning is voluntary. Third, we would 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 what we would term 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. In seeking to understand this issue, 

we ask for comment on which components are the largest sources of these nonfuel 

hydrocarbons and of these which are practical to modify or remove for the evaporative 

emissions test. 

Fourth, as part of these considerations we would specifically propose that no 

preconditioning be permitted for testing of any vehicle aged more than twelve months 

from its date of manufacture. The only exception we would consider is the use of an 

aged spare tire in lieu of the spare tire on the test vehicle. For these vehicles, nonfuel 

hydrocarbon emissions would 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 would presumably be encompassed within the margin 

below the standard created by this natural off-gassing. EPA asks comment on how to 

address testing of vehicles with relatively new drive tires and whether used drive tires 

should be allowed in these circumstances. Data available to EPA indicates that the 

background emission rate stabilizes to about two-thirds of the level of the standard after 

about twelve months. These levels are adequately below the proposed Tier 3 evaporative 

emission standards so that nonfuel background would not unduly influence test pass/fail 

outcomes and are within the range of values EPA expects to be accommodated within the 

proposed evaporative emission standard. This proposed restriction for vehicles older than 

12 months would include certification, confirmatory and in-use testing for any vehicle 

certified to the proposed Tier 3 evaporative emission standards. We request 

manufacturer data related to the change in nonfuel hydrocarbon emission rates over time 

and on the best method to consider these emissions as part of preconditioning before 

evaporative emission testing. 

d. 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 
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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. CARB always specified EPA test conditions for 

refueling as they were deemed worst case. CARB recently moved to change their 

certification test fuel to a 7 RVP gasoline with 10 percent ethanol and as discussed in 

Section IV.D., we are now proposing to change the Federal certification test fuel 

specification to a 9 RVP gasoline with 15 percent ethanol.

 During the development of this proposal we carefully considered the practice of 

CARB/EPA reciprocity with regard to certification test fuels, hot soak plus diurnal test 

procedures, and emission test results when it comes to evaporative emissions 

certification. With this notice we are proposing a revised approach to the CARB/EPA 

reciprocity with regard to evaporative and refueling emissions. A uniform national 

certification test fuel is important to the design of fuel/evaporative systems which will 

operate effectively across the U.S. Consistent with our desire to have a national program 

with vehicles designed for E15 as discussed in Section IV.D, and consistent with our 

treatment of exhaust emission standards, we are proposing a 9 RVP test fuel with 15 

percent ethanol for all evaporative (hot soak plus diurnal, canister bleed, and leak 

emission standards) and refueling emissions testing. Thus, after the evaporative 

emissions fuel phase-in discussed above (ending after the 2019 MY), EPA will no longer 

accept test data on CARB test fuel and diurnal test temperatures. However, CARB has 

agreed to accept emission test data on EPA test fuel and temperature conditions for 

certification such that a uniform national program could still exist. This approach applies 

to all evaporative and refueling emission standards.

Generally, any vehicle family counted in the Tier 3 evaporative emission 

standards phase-in must be certified on Tier 3 certification test fuel using EPA test 

procedures. However, EPA recognizes that the California and federal evaporative 

emission standard programs would be starting from different bases and that the transition 

provisions are different in some ways. For example, the proposed 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 2017. To capitalize on this 

technology and to facilitate transition, we are proposing that any CARB evaporative 

emission test data from MYs 2015 and 2016 certifications could be used in federal 

certification for those evaporative/refueling families through the 2019 MY. Assuming 

these vehicle families meet Tier 3 evaporative emission standards and they are sold 

nationwide they could be included in the percentage phase-in calculations as Tier 3 

vehicles. A good example of these would be vehicles meeting CARB Option 1 standards 

discussed above. If the vehicles do not meet the Tier 3 evaporative emission 

requirements manufacturers could potentially sell them nationwide, but they would not be 

included as compliant vehicles in the percentage phase-in calculation. EPA proposes a 

similar provision for a manufacturer which elects to use the CARB test procedures and 

test fuels to meet the refueling emission standard. That is, if a manufacturer uses 

evaporative emission test data from 2015 or 2016 model year CARB certifications to 

meet the Federal requirements in 2017-2019 model years, it may also use CARB 

refueling emission test data from model year 2015 and 2016 certifications for federal 
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certification for the refueling requirements for those evaporative/refueling families 

through the 2019 MY. Any in-use testing on vehicle families certified on this data would 

be conducted using the CARB temperature conditions and test fuel and the CARB 

ethanol SHED adjustment value of 1.08 for 10 percent ethanol. However, by the 2020 

MY all vehicles would have to be certified using EPA certification test fuel and test 

procedures. In the interim, the equivalency and acceptance by EPA of certification on 

California test fuels is dependent on our proposed 9 psi RVP level for the certification 

test fuel. Were we to require the more stringent level of 10 psi RVP more typical of E10 

as discussed in section IV.D.1, testing using California test fuels and conditions would no 

longer be equivalent.

e. Evaporative and Refueling Emission Standards for Various Fuels

The evaporative and refueling emission standards today apply in different ways to 

different fuels. In the case of gasoline, all the standards apply and testing is required for 

certifying all vehicles. Evaporative emission standards do not apply for diesel-fueled 

vehicles; the refueling standards apply to diesel-fueled vehicles, but manufacturers can 

get EPA approval to omit testing for certification. For other fuels, there is a mix of 

standards applying or not applying, and if standards apply, testing is either required or not 

required. The statutory provisions in this regard are straightforward—Clean Air Act 

section 202(k) specifies that gasoline-fueled vehicles must be certified to evaporative 

emission standards, and section 202(a)(6) specifies that all motor vehicles be certified to 

refueling emission standards. This raises two questions. First, we request comment on 

using this rulemaking as the proper context for applying the refueling standards to 

vehicles powered by every kind of fuel. Where standards do not apply today (natural gas, 

fuel cells, electric, etc.), we would expect to waive test requirements for certification, so 

this would not be any substantial burden. Dedicated ethanol-fueled vehicles would face a

new requirement, but we are not aware that there are any such vehicles today. 

Second, we have the discretion to apply evaporative emission standards to 

vehicles powered by fuels other than gasoline. The standards expressly do not apply for 

diesel fuel. By omission, the standards do not apply for dedicated ethanol-fueled 

vehicles, fuel-cell vehicles, and electric vehicles. The standards apply for natural gas and 

liquefied petroleum gas even though these are sealed systems with no emission control 

systems for controlling evaporative emissions. We request comment on adjusting the 

regulations such that evaporative emission standards apply only to volatile liquid fuels, 

which is the approach we have taken for nonroad applications (see, for example, 40 CFR 

1060.801). Under this approach, diesel fuel would continue to be excluded from 

standards because it is nonvolatile. This approach would also exclude natural gas and 

liquefied petroleum gas because they are not liquid fuels at atmospheric pressure. 
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5. Improvements to In-Use Performance of Fuel Vapor Control Systems 

a. Background on Data Related to In-Use Performance

As part of the Compliance Assistance Program (CAP 2000) in-use verification 

program (IUVP)309 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.310 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 covers about 

1800 vehicle tests. This data shows 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). The 

useful life period for LDVs and LDT1s/LDT2s is 10 years/120,000 miles, for 

LDT3s/LDT4s/MDPVs and complete HDGVs it is 11 years/120,000 miles. Thus, few

firm conclusions can be drawn about full useful life emissions performance.

Recent evaporative emission testing conducted by EPA and others evaluated inuse LDVs and LDTs certified to meet the enhanced evaporative emission standards 

implemented for 1996 and later model years311 as well as Tier 2 standards implemented 

for 2004 and later model year vehicles. Three Coordinating Research Council (CRC) 

programs (E-77-2/2b/2c), tested evaporative emission levels of vehicles with varying 

amounts of ethanol and levels of RVP in the gasoline test fuel.312 These programs were 

unique in that a subset of the vehicle SHED tests were of vehicles with implanted leaks at 

the nominal minimal level of detection for OBD systems (0.020 inch) in three different 

 

309 64 FR 23906 (May 4, 1999).

310 65 FR 59922-59924 (October 6, 2000).

311 58 FR 16002 (March 24, 1993).

312 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.
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locations in the fuel/evaporative control system. These tests showed hydrocarbon 

emission rates 2-10 times greater than for the same vehicles tested in the SHED without 

the leaks and showed an order of magnitude of difference depending on where the leak 

was introduced.

Furthermore, the CRC E-77-2 evaporative emissions test programs which looked 

at permeation in aged vehicles meeting EPA’s enhanced evaporative emission control 

standards, introduced a new Static Test Procedure which pressurized the vapor space and 

activated the fuel pump during different portions of the SHED test, while the vent from 

the vehicle canister was routed to a trap canister outside of the SHED. By pressurizing 

the vapor space it was possible to determine if there was a vapor leak in the system by

looking for a slope change in the vapor concentration in the SHED over time relative to 

permeation alone. Similarly, by activating the fuel pump it was possible to determine if 

there was a liquid leak in the system by looking for a slope change in the vapor 

concentration in the SHED over time relative to permeation alone. Out of the 15 

randomly recruited vehicles in the program, seven of them displayed vapor and/or liquid 

leaks on one or more fuel ethanol/RVP combination (4 of these 7 were Tier 2 vehicles). 

A closer look at the data indicates that over the course of the study, which covered a two 

to four year period depending on the vehicle, the magnitude of the leaks increased with 

time.

These studies taken together were of concern to EPA with regard to the in-use 

performance of evaporative emission control systems because they indicated that leaks 

could be a large portion of the evaporative emissions inventory if they occurred in even a 

relatively small fraction of the in-use fleet. The key missing piece of information was 

how often the leaks of 0.020 inches or larger occur in the fleet.

To help us better understand this concern, EPA partnered with the Colorado 

Department of Public Health and Environment (CDPHE) and with CRC as an advisor for 

a pilot field study in Denver in the summer of 2008 to assess the frequency of high 

evaporative emissions vehicles in the fleet. The project identified high evaporative 

emission emitters through an innovative screening tool known as a remote sensing device 

(RSD). The vehicles were identified at the entrance to the Inspection and Maintenance 

(I/M) station as high evaporative emission emitters. The operators of these vehicles were 

asked to participate in further evaluation using a Portable Sealed Housing for Evaporative 

Determination (PSHED) in addition to a modified California method test procedure to 

locate the source of the high emissions indicated by the PSHED level.313 The CDPHE 

continued to collect the same type of data in different locations in the Denver area for the 

next two summers.

 

313 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, 
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Of the 5830 vehicles which came through the Ken Caryl I/M station in 2009, 601 

were identified as potentially high evaporative emitters using the RSD tool.314 Of these, 

84 vehicle owners agreed to be included in the PSHED evaluation that summer. 

Furthermore, 110 additional vehicles were recruited which were potentially low to 

marginally high evaporative emitters.315 The study was structured to recruit higher 

evaporative emitting vehicles more heavily than lower emitting vehicles. Afterwards the 

percentages were adjusted to represent the actual mix in the fleet of light duty vehicles. 

Thus, it was determined that 10 percent of the fleet had evaporative emissions which 

exceeded a cut point reflecting an in-use evaporative emission rate of about 1 gram of 

total HC over 15 minutes (see Table 5-9 in the 2012 DeFries report referenced above). 

This value is approximately the emission rate that would be expected from a leak of 

0.020 inches which is the detection standard for OBD II systems.

316

An examination of the test data reveals two additional significant points. First, 

the data indicates a trend for greater frequency of leaks in older vehicles. This is not 

unexpected given the manner in which factors such as vibration, fuel quality, weather 

elements, corrosion, maintenance, and other operating conditions affect the durability of 

system components, fittings, and connections over time. Second, there were relatively

few newer model year vehicles in the population surveyed. This is expected and almost 

unavoidable since the Colorado I/M program generally exempts vehicles which are four 

years old or newer. While it is reasonable to expect there to be a lower prevalence of 

leaks in newer vehicles, the lack of data for newer vehicles does not necessarily indicate 

that no problems exist in newer model year vehicles or that problems will not occur in the 

future with Tier 3 vehicles.

Since many of the vehicles in the sample group met OBD requirements for 

evaporative system leak monitoring, it was deemed useful to examine whether the OBD 

system identified the leak. As mentioned above, approximately 10 percent of the 

vehicles in the “adjusted fleet” had vapor leaks which were of the magnitude expected 

from a 0.020 inch or larger leak. Over the three years of study, there were a total of 180 

SHED tests (either PSHED or laboratory SHED) on vehicles with OBD data collected in 

the I/M program. Of these 180 vehicles, 171 had the evaporative OBD monitors ready. 

Of these, 171 vehicles, 20 were found to have emission rates of 1 g/15 min in the PSHED

(the emission rate linked to a 0.020” leak). Of these 20 vehicles only 3 came into the I/M 

test with an OBD diagnostic trouble code (DTC) set indicating an evaporative system 

 

314 DeFries, T; Palacios, C., Kishan, S. (2012), Estimated Summer Hot Soak Distributions for the Denver’s 

Ken Caryl IM Station Fleet.

315 A selection bin structure was used based on indicated evaporative emissions levels recruitment heavier 

at the higher emission end. Thus, there was a gradation even in the lower level bins where many of the 

vehicles would be considered marginal and not passing the evaporative emission standard even if they were 

not considered higher than the 1 g/15 minutes which our study found to be the lower range detectable by 

the RSD from the 2010 Ken Caryl report cited above.

316 Compare the first 15 minutes of hot soak data from the field studies with implanted leaks in E-77-2 

studies.
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problem.317,318 A closer look, including field inspection comments, of the 20 vehicles 

shows that half were not expected to diagnose the problem because it was outside of the 

OBD system design capabilities. Of the vehicles which potentially should have set an 

evaporative DTC, at least 50 percent and perhaps as much as 70 percent of codes were 

not set on high evap emissions vehicles. The lack of codes being set for these vehicles 

may reflect OBD performance issues or allowances (known as enable criteria) in the 

OBD regulations regarding when the OBD evaporative emission leak monitoring system 

is not required to operate or situations when the monitor is otherwise not ready for what 

may be allowable reasons such as an allowable deficiency.

To better understand this issue EPA has examined evaporative emission system 

DTC and monitor ready information from I/M programs from Texas and California.319 

Since the data was gathered by the states under different protocols and time periods, the 

content of the data sets are not identical. To provide some degree of uniformity in our 

analysis, we examined the data for five MY (2000-2004) but within each state we only 

looked at calendar years of data beginning after the initial state I/M exemption period (2-

4 calendar years depending on the state) had passed. Thus the analysis focused on I/M 

OBD information for calendar years 2004-2010. Examined together, the data generally 

indicates the following: 

 Depending on age, 0.3-2.5 percent of vehicles with evaporative monitors 

ready came into the I/M stations with evaporative related MIL or DTCs set

 The percent of vehicles with evaporative emission related MILs set increased 

by a factor of 2 - 4 over about 5 years 

 Evaporative emission monitors were not ready for 3-16 percent of vehicles 

when arriving at the I/M station.

 The percent of vehicles with monitors ready at the I/M station generally

decreased by 3 to 7 percentage points over about 5-6 years; decrease was less 

for model year vehicles less than five years old.

 While it varies by age, 60-80 percent of evaporative system DTCs are leak 

related.

 

317 In the E-77-2 programs the 0.02 inch leaks implanted near the top of the tank and at the canister 

connection had hot soak measurements which averaged approximately 1 g/15 minutes PSHED 

measurement. This also happens to be the lower end of the detectable range of evaporative emissions by

the RSD. Since the OBD monitor is expected to detect a .020” leak wherever it is located, the DTC should 

be set.

318 Palacios, C., Weatherby, M., DeFries, T., Lindner, J., Kishan, S. (2012). Evaluation of the Effectiveness 

of On-Board Diagnostic (OBD) Systems in Identifying Fuel Vapor Losses from Light-Duty Vehicles.

319 Fulper, C. (2013, February). Preliminary Analysis of OBD Evaporative System Information from I/M 

Stations - California and Texas, Memorandum to the docket.
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There is no question of the value of OBD leak monitoring for evaporative 

systems, especially when owners complete needed repairs. Undoubtedly these 

percentages and thus in-use leak values would be higher without OBD evaporative 

system leak monitoring. However, this data suggests that EPA OBD regulations in place 

for 2000-2004 MY vehicles would not alone be sufficient to address concerns regarding 

the emission effects of vapor leaks from the fuel and evaporative control systems.320

In summary, information gathered from evaporative emissions testing conducted 

in the IUVP program indicates that relatively low mileage/ newer vehicles perform well 

when evaluated under laboratory conditions. However, data gathered from in-use testing 

conducted by EPA, Colorado, and others indicates that as vehicles age some vehicles 

have a propensity to develop leaks in the fuel/evaporative system and that these leaks 

increase in size as the vehicles age. Beyond this, a review of OBD evaporative system 

leak monitor data from the I/M programs of two states revealed four important trends: (1) 

even when the OBD system identifies leaks owners do not always respond by getting the 

needed repair completed, (2) the fraction of vehicles with leaks identified by OBD 

increases as vehicles age, (3) vehicles sometimes are operating in conditions in which the 

OBD leak monitor is not ready to identify a potential problem, and (4) evaporative 

system leaks are the dominant DTC for vehicles with monitors ready and evaporative 

system DTC set..

 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 five percent of Tier 3 vehicles had a leak(s) of 0.020 inches or greater this 

would cause in-use emissions equivalent to all of the projected emission reductions from 

the proposed Tier 3 evaporative emission standards on that day.

321 Thus, EPA is 

proposing three measures to address this issue: (1) an emission standard focused on 

reducing fuel/evaporative system vapor leaks over the vehicle useful life, (2) an upgrade 

to OBD emissions monitoring requirements to improve their role in identifying problems 

and improving in-use emissions performance, and (3) additions to the IUVP program 

focused on testing a broader sample of fuel/evaporative system leaks in IUVP than is 

done for evaporative emission standards alone. 

 

320 For further information see CARB reports “Technical Status and Proposed Revisions to Malfunction and 

Diagnostic System Requirements for 1994 and Subsequent Model-Year Passenger Cars, Light-Duty 

Trucks, and Medium-Duty Vehicles and Engines (OBD II)” October, 1994 and “Technical Status and 

Revisions to Malfunction and Diagnostic System Requirements for 2004 and Subsequent Model Year 

Passenger Cars, Light-Duty Trucks, and Medium-Duty Vehicles and Engines (OBD II) March 2002. 

321 This is based on five percent of vehicles and 4-5 trips (hot soaks) per day at 1 g/hot soak. Five percent 

is a reasonable value for this illustration since as mentioned above 0.3-2.5 percent of vehicles come in to 

I/M stations with evaporative system MILs or DTCs and 60-80 percent of these were leak- related DTCs. 

Thus, it is reasonable to project that the fleet average is higher since vehicle repair just before I/M is 

common, evaporative emission monitors were not ready on 3-16 percent of vehicles, and 18 states do not 

have any form of I/M at all and repair rates in response to a MIL may be lower.
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b. Proposed Leak Emission Standard

The evaporative emission standards in this proposal will help to promote 

widespread use of improved technology and materials which will reduce evaporative 

emissions in-use. The proposed new requirement for a leak emission standard and 

procedure will help to ensure the durability of Tier 3 evaporative emission control 

systems nationwide.

Based on the information described above concerning evaporative emissions inuse, we believe a leak emission standard is necessary to meet our goal that vehicles 

meeting Tier 3 evaporative emission requirements not have fuel/evaporative system 

vapor leaks. Toward that end, we are proposing a leak emission standard that would have 

to be met both at new vehicle certification and in use. The leak emission standard would 

apply beginning in the 2018 MY to any vehicle certified to the Tier 3 evaporative 

emission standards or a CARB carryover vehicle counted toward the sales percentage 

phase-in requirements, including LDVs, LDTs, MDPVs, and complete HDGVs up to 

14,000 lbs GVWR. The emission standard would be applicable for the same useful life 

period as for the evaporative emission standards that apply to the vehicle. The standard 

would 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 proposing that 

the leak emission standard be expressed in the form of a cumulative equivalent orifice 

diameter. We are proposing a value of 0.02 inches.322 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 proposed 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 an emission 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. As discussed in the 

technological feasibility section above, the actions manufacturers will have to take to 

meet the proposed Tier 3 evaporative emission standards are expected to do more to 

address potential leak points and thus in a broader sense to improve in-use durability for 

evaporative control systems compared to vehicles meeting earlier or current evaporative 

emission standards. 

The proposed leak emission standard would 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. We are proposing a leak emission standard of 0.02 inches 

 

322 Current 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 emission standard value. 

We would not expect this value to exceed 0.040 inches.
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which with rounding is a bit less stringent than the 0.020 inch OBD fuel/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 emission standard and the monitor requirement which is reflected through multipliers 

for the exhaust emission standards monitored through OBD. EPA asks for comment and 

rationale on setting the standard at 0.02 inches equivalent diameter or the more stringent 

0.020 inch equivalent diameter specified for OBD evaporative system leak monitoring. If 

finalized as proposed, the emission standard would be specified to one significant digit 

(e.g., 0.02 inches) but would have to be measured and reported to at least two significant 

digits.

The proposed leak emission standard would apply at the time of certification as 

well as during confirmatory and in-use verification program testing. We do not expect 

that new vehicles being certified would 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 proposes to allow manufacturers to 

attest to compliance with the leak emission standard at certification.

To implement the proposed leak emission standard within the current regulatory

structure a few minor changes are needed. First, current 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 emission 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 emission standard is a 

pass/fail requirement and not an emission rate, there is no requirement for the application 

of a deterioration factor. Third, EPA proposes to require that the manufacturers 

recommend one or more leak entry test points for each family. This point should be 

outside of the gas cap/fillpipe area, since our experience indicates that testing could 

always be done through that point of entry to the fuel/evaporative system. 

EPA asks for comment on the timing, form and level of the proposed emission 

standard. EPA believes that linking the timing of the proposed leak emission standard to 

the implementation of proposed Tier 3 evaporative emission standards in 2018 provides 

adequate lead time and is consistent with the technical rationale supporting the feasibility

of the Tier 3 evaporative emission standard. 

c. Proposed Leak Emission Standard Test Procedure 

In order to implement a new leak emission standard, a leak test procedure is 

required. 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) 

(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 
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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 proposing 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 regards to the test procedure we will first discuss 

where the leak test could occur in the FTP test sequence. We will then discuss how the 

test is proposed to be conducted. 

First with regard to when the test would be conducted within the current FTP 

sequence we are proposing that it be inserted 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 would be: (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 proposes that the test be conducted with 9 RVP E15 test fuel for both 

certification and IUVP. This is the same preconditioning that is called for today in 40 

CFR 86 subpart B for exhaust, evaporative, and refueling emissions testing. After 

preconditioning is complete, the leak test would be conducted and the test sequence could 

then proceed as prescribed in subpart B or testing terminated if the purpose was 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 could not include any prescreening for leaks nor would any tightening of 

fittings or connections be permitted. 

After preconditioning is complete, manufacturers would then run the leak test. 

Each complete test would involve running the test procedure at one entry point in the 

system. Presumably this would be either near the back of the fuel system (perhaps near 

the gas cap) or near the front of the fuel system on the pressure side of the locations near 

where the system is sealed (perhaps at the canister vent). If the fuel/evaporative system 

has an imbedded evaporative system test port then that point could be used. 

Alternatively, manufacturers could also develop a test rig such as a “fill pipe extension” 

which would screw into the fill pipe opening using cap threads at one end and on the 

other end have threads to screw the fill pipe vehicle cap in place. Within this extension 

there would 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 would have to specify the test point at the time of the precertification meeting. If the manufacturer selected an entry point which required the fuel 

cap to be removed, then the cap would have to undergo a separate test as is now done in 

many I/M stations.323 In this case, tests from both points combined must pass the 

proposed emission standard.

The procedure would be conducted as follows:

 

323 For related information see “IM240 & Evap Technical Guidance”, EPA 420-R-00-007, April, 2000. 
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 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 proposed 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 then manufacturer must also show 

evidence that the vehicle’s fuel cap is performing properly.

324

 EPA is seeking comment on requiring two separate test points one near the 

evaporative canister and the other near the fuel cap. Furthermore, we are 

specifically proposing that in some cases two separate test points in the 

locations mentioned above would be required. This would especially be 

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. Of course, dual tank, dual canister 

systems would have to be evaluated as separate systems. Tests could 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. 

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 would, of course, monitor these fuel system 

changes and modify the test procedure provisions as needed. Furthermore, current 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 

 

324 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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approach deemed equivalent or better. EPA would make such provisions for the leak 

emission standard testing requirement. Any such special or alternative procedures would 

have to be reported under §86.004-21(b)(9).325

d. Proposed Onboard Diagnostic (OBD) System Regulation Changes

EPA has its own OBD regulations which are similar but not identical to CARB’s. 

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,326 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 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 their full 

useful life, give reliable results (find and signal only true deficiencies), and operate 

frequently during in use operation. It is permitted in current EPA regulations and 

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 proposing to 

continue that practice but to upgrade our regulations to be consistent with the latest 

CARB regulations.

EPA has reviewed the current CARB regulatory requirements related to OBD (see 

California Code of Regulations (CCR) §1968.2 dated May 18, 2010) and, as discussed 

below we are proposing to adopt most of these provisions with the Tier 3 program. We 

are proposing this for two basic reasons. First, this is consistent with the goal of a 

national program and one vehicle technology for all 50 states. Second, implementation of 

these requirements is now demonstrated technology and compliance with these 

requirements is common within the industry today. Thus, the added burden is minimal. 

Furthermore, OBD has the advantage of running frequently on in-use vehicles to identify

potential exhaust and evaporative system performance problems, so adopting these 

provisions would create the opportunity for OBD to serve a more prominent role in 

ensuring the proposed Tier 3 emission standards are met in-use. 

There is an important link between OBD provisions related to evaporative 

emission control system leak monitoring and the proposed leak test emission 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 proposed leak emission standards prohibits leaks 

of greater than 0.02 inches cumulative equivalent diameter, while the proposed OBD 

evaporative system leak monitoring provision would require that the OBD system find 

 

325 For example, MAHLE Powertrain has piece of equipment known as a Mahle Leak Tester which is now

used in assembly plants and may be adaptable to this requirement.

326 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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leaks larger than 0.020 inches cumulative equivalent orifice diameter and notify the 

owner, but with no inherent obligation to repair the problem. Thus adopting a 0.020 inch 

cumulative equivalent orifice diameter would align these two programs and, as will be 

discussed below, creates the potential for an optional leak detection test procedure for inuse testing.

To be more specific, we are proposing to update our OBD regulations to be 

consistent with current California OBD requirements add two new requirements and 

retain three minor exceptions. These changes would be fully effective in the 2017MY, 

but EPA asks comment on whether the requirement should be linked to be effective with 

certification to any of the Tier 3 emission standards (either exhaust or evaporative) or 

phased in for the 2017 model year for LDVs and LLDTs and the 2018 MY for the 

HLDTs, MDPVs, and HDGVs up to 14,000 lbs GVWR.327 EPA would continue to 

accept certifications with CARB OBD requirements as satisfying EPA OBD 

requirements. We are proposing to incorporate by reference section 1968.2 of the 

California Code of Regulations as discussed below. This would include 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 current EPA OBD requirements for 

LDVs, LDTs, MDPVs, and complete HDGVs less than 14,000 lbs GVWR.328 

The most noteworthy changes we are proposing are summarized below. The 

CCR below is the California Code of Regulations cite for each pertinent provision.

 EPA proposes to add a 0.020 inches 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 CCR 1968.2(e)). OBD leak 

monitoring systems would have to identify, store, and if required signal any

leak(s) equal to or greater than 0.020 inches cumulative equivalent diameter. 

This would thus include diagnostic trouble codes (DTC) P0440, P0442, 

P0446, P0455, P0456, and P0457.

 EPA proposes to incorporate by reference the full array of rate based 

monitoring requirements (see CCR1968.2 (d)). 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 

 

327 We are not proposing to change the requirement for incompletes and vehicles with a GVWR above 

14,000 lbs. 

328 MDVs in the CARB regulations basically incorporate MDPVs and complete HDGV less than 14,000 lbs 

GVWR as defined by EPA.
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within two weeks. This will help to improve the fraction of time monitors are 

ready to find a potential problem.

 EPA proposes to incorporate by reference provisions regarding monitoring 

system demonstration requirements for certification. We are proposing to 

incorporate by reference CARB provisions in this area and to accept 

submissions to CARB for purposes of compliance demonstration (see CCR 

1968.2(h)). Adopting current CARB monitoring system demonstration 

requirements assures that monitoring systems operate as designed when 

installed on certification vehicles.

We also propose that this certification include a requirement for 

manufacturers to demonstrate the ability of the OBD leak monitoring system 

to detect a 0.020 inch leak. Current CARB protocols do not require that 

manufacturers demonstrate that the certification vehicle can find a vapor leak 

in the fuel/evaporative system. We are proposing to add a requirement that 

manufacturers must demonstrate for certification that the OBD system can 

find and report the implanted leak would help to ensure the OBD system’s 

capability to function as designed and for the OBD-based leak based 

evaporative system leak to be used as an optional test procedure for in-use 

testing for the proposed leak emission standard. We are proposing that this be 

added for the same vehicles now required for monitoring system 

demonstration requirements for certification under CARB OBD regulations. 

Since the CARB regulation requires only a relative few vehicle models each 

year per manufacturer, we propose that manufacturers be given the option to 

either test the remainder for an implanted leak in the fuel/evaporative system 

or certify by attestation that each of their remaining families meets the 

requirement based on development and other information. 

 EPA proposes to incorporate 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 CCR 1968.2(j)) 

 For the OBD evaporative system leak monitoring requirement, EPA proposes 

a scan readable function (a new PID in Service $01 of SAE J1979) which 

could be used to indicate or ascertain the distance traveled since the OBD leak 

monitoring diagnostic was last completed successfully and if 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). Updating this PID this would be based on SAE J1979 mode 6 ($06) 

test results: “Request On-board Monitoring Test Results for Specific 

Monitored Systems.” With this proposed requirement, the PID distance 

would be initialized to maximum range of NV RAM initialization (such as 

battery disconnect or controller reprogramming) and code clear As a result, in 

the event that a vehicle had a memory clear event in the past, but has not had 

sufficient operation for the evaporative system to be evaluated, the scan 
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readable mileage function would indicate that the system had not completed a 

full leak detection of the evaporative control system within the last 750 miles 

(1200km). OBD systems already maintain information for active, pending, 

historic and permanent codes. This would be a modest upgrade to this 

requirement which would enable the use of the OBD-based evaporative 

system leak monitor with the IUVP program as discussed below. See CCR 

1968.2 (g) for information related to code storage. EPA seeks comment on 

alternative equivalent approaches (e.g., a scan readable mileage stamp or flag 

traceable to mileage indicating when the full OBD leak monitoring protocol 

was last completed successfully and the result (p/f)) which accomplish the 

same objective and whether this capability should be optional for the 2017 

MY since this requirement is designed to enable the use of OBD in leak 

emission standard testing and that standard is proposed to begin in the 2018 

MY.

 The minor exceptions which are contained in EPA’s current OBD regulations 

are proposed 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) would not be 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, would apply only to vehicles equipped with variable valve timing. 

For all model years, the deficiency provisions of paragraph (i) of the current 

regulations apply only to alternative fuel vehicle/engine manufacturers 

selecting this paragraph for demonstrating compliance.

If adopted, these proposed changes, taken together would improve the 

performance, reliability, general utility, and effectiveness of OBD systems for Tier 3 

exhaust and evaporative emission controls. Furthermore, if adopted, these changes create 

the opportunity for OBD evaporative system leak monitoring systems to serve a more 

prominent role in ensuring compliance with the leak emission standard. EPA believes 

that they could be implemented for minimal cost since most manufacturers are meeting 

them today and will have to for LEV III vehicles. However, EPA requests comment on 

applying the proposed new OBD requirements to small business vehicle manufacturers 

and independent commercial importers. 

As discussed below, the proposed OBD requirements would apply to small 

entities and independent commercial importers (ICI) in the 2022 MY. Small alternative 

fuel converters would 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 would consider these changes and propose to adopt them or 

incorporate them by reference, if appropriate. In fact, CARB is currently proposing some 

changes to its OBD program in response to the LEV III program exhaust emission 
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standards. 330 We request comment on incorporating these changes into this rule or other

rules in the future. We also would generally expect to continue the current practice 

allowed by EPA regulations which is for EPA to accept CARB OBD certifications as 

satisfying EPA requirements provided that they include at least all of the requirements 

covered by the EPA regulations. 

e. In-Use Verification Program (IUVP) Requirements for the Leak Emission 

Standard 

i. Introduction

We believe it is important to identify leaks since vehicles with leaks would be 

expected to have daily emission rates above the proposed Tier 3 evaporative emissions 

standards and the Colorado data suggests 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 will be important to 

capturing the emission benefits of the proposed evaporative emission requirements.

Toward that end, EPA is proposing to include assessment of compliance with the 

leak emission standard within the IUVP program. 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 emission standard because it is less burdensome and is 

cost effective for accomplishing the objective. EPA believes adding a leak test 

requirement does not create an unreasonable burden. The draft 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). 

ii. IUVP Test Requirements 

We are proposing that the leak emission test be conducted for each and every

vehicle assessed in IUVP for exhaust emissions under 40 CFR 86.1845.04. This would 

begin for 2018 MY certifications for vehicle families meeting the proposed new leak 

emission standard. This would include 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 year point. We 

are proposing this approach to implementing IUVP for the leak emission standard in lieu 

of creating a new set of requirements which would require yet another set of vehicles to 

 

330 CARB has recently proposed some minor OBD program modifications in their recent LEVIII ISOR, and 

EPA asks for comment on including those provisions within the proposed EPA OBD program. See pages 

61-72 of the CARB Staff Report at http://www.arb.ca.gov/regact/2012/leviiighg2012/levisor.pdf and pages 

A11-A125 of the regulatory text at http://www.arb.ca.gov/regact/2012/leviiighg2012/levappa.pdf. 
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be procured for testing. We are not proposing to include the leak test with any

evaporative emissions test in IUVP, since a leak would be evident in the results of the 

evaporative emissions test.

The current 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/leak test families and exhaust emission test groups may cover one 

or more of the same evaporative/refueling/leak families, so we would expect to receive 

multiple leak emission 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 would 

consider extending the age point for leak emission 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 asks comment on the viability of 

extending leak emission IUVP testing beyond the nominal four year point, (e.g., six to 

eight years). We recognize that there are cost and vehicle procurement issues, but the 

Colorado data strongly suggests a relationship between vehicle age and the propensity for 

the development of leaks.

iii.Assessment of IUVP Leak Emission Standard Test Results

The current 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 emission 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 proposed 

leak emission standard is 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 emission standard in assuring in-use evaporative 

emissions control, we are proposing a set of criteria for assessing leak emission 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 emission standard, 

testing is complete. This applies to cumulative testing for that family
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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 emission 

standard testing is complete. If that vehicle does not pass the leak emission 

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 would not be limited to detailed system design, calibration, 

and operating information, technical explanations as to why the individual vehicles tested 

failed the leak emission 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 emission 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 would propose to operate within the basic structure of the IUCP program in 

the current 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 diurnal SHED test to supplement leak emission test results. We propose 

that EPA must approve this plan before testing begins. As prescribed now in the IUCP 

regulations for exhaust, if five vehicles were tested and all passed the leak emission 

standard then testing would be complete. If all five vehicles did not pass, then five more 

would be tested. More vehicles could be tested at the manufacturer’s discretion but all 

testing would have to be completed within the time period specified in the regulations 

today. EPA and the manufacturer would then enter into discussions regarding 

interpretation, technical understanding, and compliance/enforcement implications of the 

test results, if any. 

iv. Proposed Optional Test Procedure Approach for IUVP/IUCP
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Assuming implementation of the OBD regulation changes proposed in Section 

IV.C.5.d, above, EPA is proposing an optional approach to a portion of the leak emission 

test procedure discussed in Section IV.C.5.c. This optional testing approach would be 

included in the proposed IUVP/IUCP testing program for the leak emission standard, but 

would not be used for certification testing for the leak emission standard. It would be 

considered an approach which could be used by the manufacturers to assess compliance 

with the leak emission standard. EPA could also use this procedure for conducting 

assessments and asks for comment on using this procedure for compliance purposes with 

a 0.02 inch cumulative equivalent diameter orifice standard.

Under this optional approach manufacturers would 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. This approach relies on the leak emission 

standard equivalent orifice diameter being established at the same level as proposed for 

OBD (0.020 inches). Thus, the IUVP/IUCP protocol would be modified and simplified to 

expedite completion of testing and reduce costs.

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 had 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 was indicated 

(diagnostic trouble codes P0440, P0442, P0446, P0455, P0456, and P0457), the vehicle 

would be been deemed to have met and passed the leak emission standard test 

requirement. However, if the system had not successfully completed a full OBD-based 

evaporative system leak check within 750 miles with no problem indicated then the 

manufacturer would 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 would be based on the OBD test result. This 

optional protocol could apply to every leak emission standard test after certification 

unless not approved by EPA for IUCP under 40 CFR 1846.01(i). Replicate tests would 

not be required or allowed but void tests could be repeated. 

Furthermore, EPA proposes to allow the manufacturer to run the stand alone EPA 

leak test in several situations. First, manufacturers could conduct the stand alone test to 

confirm that a problem identified by the OBD-based evaporative system monitoring leak 

check was a leak and not a problem with the OBD leak monitor itself. Second, a 

manufacturer could run the stand alone EPA leak test to confirm that the leak value 

identified by the OBD system was truly above the level of the proposed leak emission 

standard. Third, it could be used for vehicles which had not successfully completed a full 

OBD-based evaporative system leak monitoring check within the last 750 miles. Fourth, 

it could be used to confirm that a DTC set within the last 750 miles actually indicated the 

presence of a leak(s) greater than the proposed standard. However, if a manufacturer 

elected to use only OBD-based evaporative system leak based monitoring in its IUVP 
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testing; these results would be the basis for decisions regarding IUCP. As is required in 

the current IUVP regulations, all test data whether OBD based or based on EPA’s stand 

alone test procedure would have to be reported to EPA.

There could 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 would have to be 

operating to create the pressure or vacuum and because the engine is operating this would 

require the OBD-based leak test to be stand alone after the preconditioning sequence is 

complete. This would be more challenging for natural vacuum leak detection systems 

unless extended driving was involved to create the fuel system heat needed for a natural 

vacuum event or this was 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 an active or 

pending leak DTC already set in the computer and/or an MIL indicated. In this case, 

EPA would permit the manufacturer to run the OBD-based leak test and/or the stand 

alone EPA leak test or concede that the vehicle would not pass the leak emission 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 emission assessment, 

so a manufacturer would be permitted to correct the problem before testing and clear this 

OBD code before testing or run the stand alone EPA leak test. 

6. Other Initiatives

This proposal includes consideration of several amendments or clarifications to 

existing requirements related to evaporative emissions. As part of this process, 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 emission standards and the 

recently adopted greenhouse gas standards to vehicle manufacturers, we 

believe it would be advantageous to have the regulations related to their 

certification requirements written together as much as possible to reduce 

burden and increase efficiency. We are therefore proposing to move the 

emission standards and certification requirements from 40 CFR part 86 to the 

new 40 CFR part 1037, which was originally used for greenhouse gas 

standards for heavy-duty highway vehicles. This is not intended to change the 
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requirements that apply to these vehicles, except as noted in this section. We 

propose to make the provisions in part 1037 effective with model year 2014.

 As described in Section VI.C.3, we are proposing to allow for certifying 

vehicles above 14,000 lbs GVWR based on an engineering analysis instead of 

new testing (as is currently allowed for vehicles at or above 26,000 lbs 

GVWR). We are also proposing to clarify the provisions describing how the 

certification process plays out for these vehicles. 

 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 current regulation the potential for a 

waiver from testing depends 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 proposing to withdraw 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 cooler than the 

tank fuel. 

 When adopting the most recent evaporative emission change we did not carry 

through the changes to the regulatory text applying evaporative emission 

standards for methanol-fueled compression-ignition engines. The proposed 

regulations correct this oversight.

 We are proposing 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 proposed approach 

would require testing complete vehicles with any auxiliary engines (and the 

corresponding fuel-system components). Incomplete vehicles would be tested 

without the auxiliary engines, but any such engines and the corresponding 

fuel-system components would need to meet the standards that apply under 

our nonroad program as specified in 40 CFR part 1060.

 We are proposing to remove the option for secondary vehicle manufacturers 

to use a larger fuel tank capacity than is specified by the certifying 

manufacturer without re-certifying the vehicle. Secondary vehicle 

manufacturers needing a greater fuel tank capacity would need to either work 

with the certifying manufacturer to include the larger tank, or go through the 

effort to re-certify the vehicle itself. Our understanding is that this provision 

has not been used and would be better handled as part of certification rather 

than managing a separate process. We are proposing corresponding changes 

to the emission control information label.
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 Since we adopted evaporative emission standards for gaseous-fuel vehicles, 

we have developed new approaches for design-based certification (see, for 

example, 40 CFR 1060.240). We request comment on changing the 

requirements related to certifying gaseous-fuel vehicles to design-based 

certification. This would allow for a simpler assessment for certifying these 

vehicles without changing the standards that apply.

 With regard to OBD, we note also that under §86.1806-01(b)(4) OBD systems 

must have the ability to detect absence of purge air flow from a complete 

evaporative emission control system. This is clearly important because the 

proper operation of an integrated evaporative/refueling emission control 

system depends on purge. Similarly, evaporative/refueling system operation 

depends on the presence, proper adsorption/desorption performance, and 

sustained working capacity of the activated carbon canister. It is thus curious 

to observe that the current OBD provisions do not directly address the 

activated carbon canister in any way. The absence of the canister would likely

be noted as a gross leak and/or a problem with purge. Nonetheless, we are 

seeking comment on a provision which would require the OBD system to 

sense for evidence of ongoing adsorption and desorption of hydrocarbon 

vapors. These could both be sensed by changes in canister carbon bed 

temperature or perhaps for the presence of vapor in the fuel going to the intake 

manifold after a cold start or refueling event. In some cases, EPA believes 

these parameters could be monitored by hardware and sensors now on most 

vehicles and thus this might be primarily an OBD software change. Similarly, 

we are seeking comment 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.

 With future technology, we anticipate a trend toward the implementation of 

fuel tanks with higher operating pressures and in some cases fuel tanks which 

are sealed to the atmosphere during normal operation. Data available to EPA 

indicates that a leak in such a system will result in substantial emissions 

relative to very low pressure systems which employ running loss control 

strategies and an activated carbon canister as part of the methodology to 

control vapor emissions.331 Based on this concern, we are seeking comment 

on the feasibility and cost of requiring the OBD leak detection monitoring

system to detect and signal the presence of a smaller diameter orifice than 

proposed for non-pressurized systems (~ 0.010 inch) upstream of the purge 

valve for all 4 vehicle categories LDV, LDT, MDPV, and complete HDGVs 

up to 14,000 lbs GVWR. This would apply to any vehicle with a designed inuse operating pressure in excess of 0.36 psi (10 inches water). As a means to 

 

331 EPA Memorandum, "Presentation on Evaporative Emission System Leaks for a Fuel Tank Under 

Pressure", Glenn W. Passavant, February, 2013.
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prevent a sealed fuel tank from venting leaks directly to atmosphere, we ask

for comment on an added requirement that the fuel vapor vent valve be set to 

the open position at key off (and vent to the canister) if the OBD system 

detected a leak and triggered an MIL related to any leak greater than a preestablished threshold. The vent open at key off concept for pressurized fuel 

systems would not be intended to disenable the OBD system from conducting 

its normal evaporative system check during operation. Furthermore, as 

discussed above, we are proposing a 0.020” leak detection threshold for all 

systems. However, we are asking for comment on setting the threshold in the 

0.010”-0.015”range for pressurized systems. In the context of this request for 

comment, we ask for input regarding the feasibility of the smaller threshold, 

the effects of the vent valve open requirement on ORVR, and the repairability

of leaks of less than 0.020”

D. Emissions Test Fuel 

1. Proposed Changes to Gasoline Emissions Test Fuel

In-use gasoline has changed considerably since EPA’s fuel specifications for 

emissions testing of light- and heavy-duty gasoline vehicles were first set and last 

revised. Gasoline sulfur and benzene have been reduced and, perhaps most importantly, 

gasoline containing 10 percent ethanol by volume (E10) has replaced clear gasoline (E0) 

across the country. This has had second-order effects on other gasoline properties. Inuse fuel is projected to continue to change with the implementation of the RFS2 program 

(e.g., the expansion of the number of retailers that offer E15) as well as today’s proposed 

Tier 3 gasoline sulfur program. As a result, we are proposing to update our federal 

emission test fuel specifications not only to better match today’s in-use fuel but also to be 

forward looking with respect to future ethanol and sulfur content.332 The revised test fuel 

specifications would apply for exhaust emissions testing, fuel economy/greenhouse gas 

 

332 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 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 commonly referred to as “certification fuel,” the test fuel specifications proposed today 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 proposing changes to the specifications for fuel used during durability related aging that is part of the 

certification process. The proposed changes only apply to the test fuel used during emissions testing, both 

for purposes of certification and for later compliance related testing.
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testing, and emissions testing for non-exhaust emissions (evaporative, refueling, and leak 

detection testing). The proposed gasoline specifications, found at §1065.710, would 

apply to emissions testing of light-duty cars and trucks as well as heavy-duty gasoline 

vehicles certified on the chassis test, those subject to the proposed Tier 3 standards.333

We are not proposing changes to 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) currently specified at §86.113-04(a)(3)(i). Those 

provisions require that “Unless 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 would expect that 

manufacturers would use service accumulation fuels which 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, as E15 

in-use fuel becomes progressively more available, we would expect that E15 service 

accumulation fuel would be used for whole vehicle evaporative 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. 

Where possible, we are proposing changes consistent with the CARB’s planned 

LEV III gasoline test fuel specifications.334 Below is an overview of some of the key

changes. A summary of the proposed test fuel specifications is provided in Table IV-21. 

 

333As discussed in Section IV.C, we are also seeking comment on requiring the proposed 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.

334 The LEV III program as approved by the California Air Resources Board, January 2012
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For more information on how we arrived at the proposed test fuel property ranges and 

ASTM test methods, refer to Chapter 3 of the draft RIA.

 Ethanol - adding a 15 volume percent ethanol specification to be forwardlooking with respect to the maximum gasoline ethanol concentration Tier 3 

vehicles could expect to encounter. EPA recently issued a waiver under 

section 211(f)(4) of the CAA permitting E15 to be introduced into commerce 

for use in MY2001 and newer light-duty motor vehicles.335 While E15 is only 

commercially available at a limited number of fuel retailers, EPA believes it 

could become a major gasoline blend over the next 10-15 years given 

instability in crude oil pricing and growing RFS2 renewable fuel 

requirements. The use of E15 as the emission test fuel will help ensure that all 

future vehicles are capable of meeting Tier 3 emission standards while 

operating on E15. 

 Octane - lowering gasoline octane to around 87 (R+M)/2 to be representative 

of in-use fuel, i.e., regular-grade gasoline. Manufacturers could continue to 

use high-octane gasoline for testing of premium-required336 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 would allow the manufacturer to test on a fuel with a 

minimum octane rating of 91 (R+M)/2 (in lieu of the proposed 87 (R+M)/2 

general test fuel). According to the proposed 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 would be the same as those 

proposed in Table IV-21. We seek comment on the need for limiting the 

maximum octane of gasoline used in the certification of premium-required 

engines and vehicles. 

 

335 On Nov. 4 2010, EPA issued a partial waiver for MY2007 and newer light-duty motor vehicles (75 FR 

68094). On January 26, 2011, EPA extended the waiver to MY 2001-2006 light-duty motor vehicles (76 

FR 4662).

336 Premium-required defined at §1065.710(d).
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 Distillation Temperatures - adjusting gasoline distillation temperatures to 

better reflect today’s in-use gasoline/E10. This includes minor T10, T90 and 

FBP adjustments based on AAM in-use fuel surveys and refinery batch test 

data, with additional adjustments to reflect future E15 performance 

(significantly lower T50 range). We seek comment on the appropriateness of 

the proposed distillation temperatures including the proposed 170-190 °F T50 

range for an E15 fuel. For more information on how we arrived at the 

proposed distillation temperatures in Table IV-21, refer to Chapter 3 of the 

draft RIA. 

 Sulfur - lowering the sulfur content of test fuel to 8-11 ppm to be consistent 

with our proposed Tier 3 gasoline sulfur standards. The proposed 10-ppm 

annual average sulfur 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 0.6-0.8 volume percent to 

represent in-use fuel under our new MSAT2 regulations.337 The MSAT2 

standards, which took effect January 1, 2011, limit the gasoline pool to 0.62 

volume percent benzene on average. Beginning July 1, 2012, no refinery may

produce gasoline above 1.3 volume percent benzene on average. 

 Total Aromatics - lowering the aromatics content of test fuel to better match 

today’s in-use gasoline/E10 and accommodate E15. According to AAM fuel 

surveys, the average aromatics content in gasoline has dropped 16 percent 

over the past decade due to ethanol blending.338 Additional ethanol blending 

to produce E15 is expected to result in even greater aromatics reductions. 

Accordingly, we believe the proposed 19.5-24.5 volume percent test fuel 

specification is appropriate. 

 Distribution of Aromatics – in addition to total aromatics and benzene, we are 

proposing regulations that would require a distribution of aromatics (i.e., a 

certain amount of C7, C8, C9, and C10+ hydrocarbons) to ensure that test fuel 

is more representative of in-use gasoline. Heavier aromatics in gasoline are 

believed to contribute to vehicle PM emissions, so it is important that vehicles 

are designed to meet the proposed Tier 3 emission standards on fuel with a 

distribution of aromatic compounds representative of in-use gasoline. We 

also seek comment on the need for a multi-substituted alkyl aromatics 

(MSAA) specification, as has been proposed by CARB. For more 

information on our proposed aromatics specifications, refer to Chapter 3 of the 

draft RIA. 

 

337 72 FR 8434 (February 26, 2007).

338 For more information on current aromatics levels, refer to Chapter 3 of the draft RIA.
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 Olefins - adjusting the olefins specification to better match today’s in-use 

gasoline/E10 according to AAM fuel surveys. Not only is the proposed 4.5-

11.5 mass percent range (approximately 4-6 volume percent) more 

representative of in-use fuel, the narrower test fuel range would result in more 

consistent vehicle test results. 

 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 proposed specifications are consistent with ASTM’s D4814 

gasoline specifications and CARB’s LEV III test fuel requirements.

 Updates to Gasoline Test Methods – updating some of the gasoline test 

methods currently 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. We request comment on the use of three different test methods for the 

measurement of sulfur content. 

 Consolidation of Test Fuels - consolidation of all gasoline exhaust and 

evaporative emission test fuels into a single general test fuel. This would be 

used for all on-highway vehicle testing with the exception of cold CO vehicle 

testing (which would use higher volatility test fuel) and high-altitude testing 

(which would be permitted to use lower volatility fuel). As discussed above, 

commercial gasoline would continue to be used for service accumulation 

(durability fuel). This is consistent with CARB’s LEV III approach and 

should help limit the total number of test fuels that automakers need to 

manage.

Table IV-21 Proposed Gasoline Emissions Test Fuel

Property Unit

SPECIFICATION

ASTM Reference Procedure General

Testing

LowTemperature 

Testing

High Altitude 

Testing

Antiknock Index 

(R+M)/2 - 87.0 - 88.4 87.0 Minimum

D2699-11 and D2700-11

Sensitivity (R-M) - 7.5 Minimum

Dry Vapor Pressure 

Equivalent (DVPE)

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) D5191-10b

Distillation

10% evaporated °C (°F) 49-60(120-140)

43-54

(110-130)

49-60

(120-140)

50% evaporated °C (°F) 77-88 (170-190) D86-10a

90% evaporated °C (°F) 154-166 (310-330)
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Evaporated final boiling 

point °C (°F) 193-216 (380-420)

Residue Milliliter 2.0 Maximum

Total Aromatic 

Hydrocarbons vol. % 19.5-24.5

D5769-10

C6 Aromatics (benzene) vol. % 0.6-0.8

C7 Aromatics (toluene) vol. % 4.4-5.5

C8 Aromatics vol. % 5.5-6.9

C9 Aromatics vol. % 5.0-6.2

C10+ Aromatics vol. % 4.0-5.0

Olefins mass % 4.5-11.5 D6550-10

Ethanol vol. % 14.6-15.0

Total Content of D5599-00 (Reapproved 2010)

Oxygenates Other than 

Ethanol

vol. % 0.1 Maximum

Sulfur mg/kg 8.0-11.0 D2622-10, D5453-09 or 

D7039-07

Lead g/liter 0.0026 Maximum D3237-06

Phosphorus g/liter 0.0013 Maximum D3231-11

Copper Corrosion - No. 1 Maximum D130-10

Solvent-Washed Gum 

Content mg/100 ml 3.0 Maximum D381-09

Oxidation Stability Minute 1,000 Minimum D525-05

EPA seeks comment on the appropriateness of the proposed forward-looking E15 

test fuel for light- and heavy-duty gasoline vehicles. While we believe we have 

discretion under the statute to transition from E0 to E15 test fuel, we acknowledge that 

vehicle manufacturers will need to calibrate their vehicles to meet the proposed Tier 3 

standards on fuel containing 15 percent ethanol by volume. Our analysis of the proposed 

Tier 3 standards (emission control technology, feasibility, cost, etc.) assumes the use of 

the proposed E15 test fuel. We anticipate that vehicle electronic control systems will be 

fully capable of adjusting to maintain emission performance when operating on E10 (or 

any remaining E0), but if E15 were not to enter the gasoline pool in significant quantities, 

it may be more appropriate to require that vehicles be calibrated for and tested on E10. 

We are seeking comment on various alternative approaches, e.g., starting with 

E10 as the test fuel and transitioning to E15 as the market further transitions to E15 in 

use. This could include a market review in 2014 or 2015 followed by regulatory action to 

implement the change from E10 to E15 test fuel, if warranted. Or, it could include the 

establishment of a “trigger point” (e.g., 30 percent of gasoline is E15) in the Tier 3 final 
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rule to prompt an automatic move to E15 after a certain period of time, e.g., two or three 

years. Or, we could simply set a future date (e.g., 2020) with sufficient time for 

transitioning to E15 test fuel. These transition approaches would give vehicle 

manufacturers additional lead time to prepare for higher ethanol concentrations in test 

fuel. We seek comment on the various transition approaches, their timing, and the 

appropriate specifications for an E10 test fuel to be used in the interim. 

While the volatility (i.e., RVP) of CARB’s E10 test fuel is 7.0 psi to be 

representative of in-use gasoline in California during summer months, conventional E10 

in the rest of the country is currently around 10 psi. Thus, should we finalize E10 instead 

of E15, in the absence of any standard to reduce the in-use RVP of E10 to 9.0 psi or 

lower, we would also have to consider raising the RVP of certification test fuel to 10 psi 

to reflect the RVP level of the current in-use fuel. Were we to raise the volatility to 10 

psi RVP, EPA believes that the proposed evaporative emission standards would be 

feasible, but this would increase the stringency of the proposed evaporative emission 

standards (see section IV.C). Changing certification test fuel to 10 psi RVP would 

increase vapor generation rates during the refueling test by about 10 percent and during 

the hot soak, diurnal, canister bleed, and running loss tests by as much as 25 percent in 

total. To the extent that the refueling test dictates the size of the canister, the increased 

vapor generation would necessitate increases in the volume of activated carbon used in 

the vehicle’s onboard canister by about 10 percent. Perhaps more importantly, 

manufacturer’s vehicle purge strategies and technologies would likely have to be 

modified to removing the larger vapor loads from the canister during vehicle operation. 

Some vehicles have adequate engine vacuum available to provide the increased purge, 

while others may require new or innovative approaches to increase purge volume or 

canister purge efficiency as discussed in the evaporative emissions technology

discussion. While we have not performed a detailed analysis, EPA estimates that on 

average the evaporative standard compliance costs could be about $10-15 per vehicle 

higher at 10 psi RVP compared to 9 psi RVP for canister and purge upgrades. With 

respect to lead time, EPA’s current proposal calls for either 40 percent of light-duty

vehicles to meet the Tier 3 evaporative emission standards in 2017 MY (percentage 

option) or for a manufacturer to sell only zero evap PZEVs nationwide (PZEV only

option). This basic approach for 2017 could still be feasible depending on the resolution 

of the test procedure issues and proposed flexibilities in phase-in schemes. 

Raising the certification test fuel to 10 psi RVP would also impact the 

equivalency of CARB and EPA refueling and hot soak plus diurnal evaporative emission 

test procedures. These potential impacts would have to be addressed to maintain 

CARB/EPA evaporative emissions test reciprocity. Furthermore, there may be test 

procedure options for minimizing the burden of changing certification test fuel RVP 

while maintaining the needed in-use control. 

EPA does not believe that a 10 psi certification test fuel would impact the 

feasibility or cost of the proposed leak emission standard or the proposed change in the 

OBD evaporative system leak detection requirements, since these are based on orifice 

diameter. Nor, do we believe that it would have any negative impact on permeation 

emissions or exhaust emissions.
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As mentioned above, EPA issued a waiver allowing E15 to be introduced into 

commerce for use in MY 2001 and newer light-duty 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 gasolinepowered nonroad products (which includes boats).339

 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). If, as 

discussed in this proposed rule, any class of new heavy-duty gasoline vehicles or engines 

begin testing on E15 for certification, EPA would not need to issue a waiver under 

section 211(f)(4) to allow introduction of E15 into commerce for use in these vehicles 

certified on E15 test fuel. However, EPA acknowledges that changes to the gasoline 

pump label and prohibitions finalized in the E15 Misfueling Mitigation Measures Rule 

would have to be made before E15 could lawfully be sold for use in these heavy-duty 

vehicles. This would be addressed in a future action. 

As discussed above in Sections IV.A.7.c (tailpipe emission testing) and IV.C.4.b 

(evaporative emission testing), we are proposing to require certification of all Tier 3 

light-duty and chassis-certified heavy-duty gasoline vehicles on E15 test fuel. As 

described in those sections, we are proposing that EPA still accept testing for certification 

on CARB’s E10 test fuel during the phase-in periods for the respective proposed Tier 3 

vehicle tailpipe and evaporative emissions standards and, if certified on CARB’s E10 test 

fuel, that EPA would not perform or require in-use exhaust or evaporative testing on E15 

test fuel.

As mentioned earlier, we plan to continue to allow manufacturers to test vehicles 

on premium-grade gasoline should the vehicles require it. Since we cannot predict all 

future changes in gasoline vehicle technologies and in-use fuels, we are proposing to 

allow vehicle manufacturers to specify an alternative test fuel under certain situations. 

Under this proposal, 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 could 

petition the Administrator for approval of a higher octane, higher ethanol content test fuel 

if they could 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 

 

339 76 FR 44406 (July 25, 2011).
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fuel by using it to enable more fuel efficient engines. We seek comment on the 

appropriateness of the alternative test fuel provisions at §1065.701(c) and the need to 

specify more precisely the makeup of such a fuel (ethanol content, as well as other fuel 

parameters) in the regulations at this time. We are also seeking comment on whether 

there are other aspects of today’s proposed standards that might need to be modified to 

provide an incentive for, or remove obstacles to, the development of highly efficient 

vehicles optimized for use on higher level ethanol blends.

2. Proposed Flexible Fuel Vehicle Test Fuel 

While the Agency has for some time had testing requirements for flexible fuel 

vehicles (FFVs) on E85 fuel blends, EPA currently has no regulatory specifications for 

the test fuel itself. Historically, our laboratory practice has been to blend indolene (E0) 

with neat ethanol and normal butane to produce an FFV test fuel with 83 volume percent 

ethanol and an RVP from 6.0 to 6.5 psi. However, the lack of E85 test fuel specifications 

has caused confusion and inconsistency among FFV manufacturers in carrying out their 

certification requirements. 

Similar to the previous discussion regarding gasoline test fuels, we believe it is 

important that the fuel used to test FFVs reflect the composition of actual in-use E85. 

This may become increasingly important if E85 usage in FFVs increases to help satisfy 

the growing RFS2 renewable fuel requirements. 

The term “E85” has historically been used to describe an ethanol blend with a 

maximum ethanol content of 83 volume percent and specified minimum ethanol content 

for use in FFVs. In the recently updated ASTM International specification, the minimum 

ethanol concentration was reduced from 68 to 51 volume percent.340 As part of the 

updated specification, ASTM retired the name E85 because it has caused confusion 

regarding the necessary variability in the ethanol content of the blend depending upon 

seasonal climactic conditions. The official name in the new ASTM specification is 

“ethanol fuel blends for flexible-fuel automotive spark-ignition engines”. For the sake of 

brevity, we shall refer to this fuel as E51-83. 

Consistent with our current policy regarding the formulation of FFV test fuel, we 

believe that the ethanol content should be at or near the maximum ethanol level on which 

the vehicles were designed to operate to ensure that the testing reflects the full range of 

in-use formulations and emissions performance. To provide adequate flexibility for test 

fuel manufacturers, we are proposing that the ethanol content must be from 80 to 83 

volume percent. Rather than specify ranges for the other fuel parameters as we have 

done for gasoline test fuel in Table IV-21, we are proposing that the FFV test fuel would 

be defined based on the results from blending the proposed E15 standard gasoline test 

fuel with ethanol. We propose that denatured fuel ethanol (DFE) that meets the proposed 

 

340 ASTM International D5798-11, “Standard Specification for Ethanol Fuel Blends for Flexible-Fuel 

Automotive Spark-Ignition Engines”.
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specifications would be used to increase the ethanol content to 80 to 83 volume 

percent.341 

It is important to ensure that the volatility of FFV test fuel meets minimum 

volatility specifications to provide adequate startability and for safety reasons. The 

ASTM minimum RVP specification that conforms to the specified temperature at which 

FFV emission testing takes place (68 to 86 °F) is 5.5 psi. EPA conducted discussions 

with vehicle and test fuel manufacturers to arrive at the current guidance that the RVP of 

the finished test fuel should be between 6.0 and 6.5 psi. We propose to formalize the 

current guidance in the regulatory requirements for FFV test fuel. We propose that 

commercial grade normal butane could be added to trim the RVP of the finished test fuel 

to meet the proposed specifications.342 A 6.0 to 6.5 range in RVP has historically

provided test fuel manufacturers adequate flexibility in formulating test fuels. Limiting 

the amount of butane that is added to formulate FFV test fuels is important because if 

excessive volumes of butane were used it could inappropriately reduce the stringency of 

emissions testing. 

As an alternative to the use of DFE to manufacture FFV test fuel, we propose that 

neat (undenatured) fuel grade ethanol could be used. We also propose that as an 

alternative to using a finished E15 standard gasoline test fuel in the manufacture of FFV 

test fuel, that the gasoline blendstock used to produce a compliant E15 test fuel could be 

used to manufacture the FFV test fuel. This would allow ethanol to be blended only once 

to produce FFV test fuel. The test fuel manufacturer would be required to test a sample 

of the subject gasoline blendstock after the addition of ethanol to produce a finished 

standard E15 gasoline test fuel and demonstrate that the blend meets all of the proposed 

requirements for standard gasoline test fuel described in Section IV.D.1.

We propose that the above FFV emissions test fuel specifications would become 

applicable on the same schedule as the proposed E15 standard gasoline test fuel 

specifications become applicable for light- and heavy-duty gasoline vehicles (described 

below in Section IV.D.3). We believe that the proposed requirements would ensure that 

FFV test fuel reflects the composition of in-use ethanol fuel blends for flexible-fuel 

automotive spark-ignition engines while minimizing the burden on the industry with 

respect to test fuel formulation and the number of test fuel blend components that must be 

stored. 

Under the Tier 2 program, FFVs utilize a test fuel containing 10% ethanol with an 

RVP of approximately 10 psi for evaporative emission testing. The proposed E15 

certification fuel for non-FFVs is a 9 psi E15 fuel. We seek comment on whether the new 

E15 evaporative emissions test fuel for FFVs should continue to have an RVP of 10 psi to 

maintain the level of performance established under the Tier 2 program. 

 

341 The proposed requirements for DFE are contained in Section V.C of today’s preamble.

342 The specifications for commercial grade butane are contained in 40 CFR 80.82.
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3. Proposed Implementation Schedule 

As described earlier in Section IV.C, we are proposing Tier 3 exhaust and 

evaporative emission standards with today’s notice. The proposed changes in the 

specifications for test fuel would apply to vehicles certified to these new standards. We 

are proposing to transition to the new test fuel during the first few years that the Tier 3 

standards are phasing in. As described in Sections IV.A and IV.B, testing with the new 

fuel would start 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 300 (for Class 3). Starting with model years 2020 for light-duty and 

2022 for heavy-duty, we would require that all manufacturers use the new test fuel for all 

exhaust emission testing (with the exception of Small Volume Manufacturers and small 

businesses, which could delay using the new test fuel until model year 2022). 

Manufacturers would also need to comply with cold temperature CO and NMHC 

standards using the new test fuel for any models that use E15 test fuel for meeting the 

light-duty Tier 3 exhaust emission standards. These same tests would 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. 

We are proposing to require evaporative emission testing with the new test fuel 

for any models that are 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 would 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 propose to 

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.

4. Potential Implications on CAFE Standards, GHG Standards, and Fuel 

Economy Labels 

EPA and the National Highway Traffic Safety Administration (NHTSA) recently

finalized a joint greenhouse gas (GHG) emissions and corporate average fuel economy 

(CAFE) standards for MY 2017-2025 light-duty vehicles, light-duty trucks, and mediumduty passenger vehicles.343

 These GHG and CAFE standards build upon the National 

Program that was first announced by the President in May 2009 and which allows 

manufacturers to build a single fleet of light vehicles that can satisfy all federal and state 

requirements for GHG emissions and fuel economy. The first round of standards by EPA 

and NHTSA under the National Program cover MY 2012-2016.344

The recently finalized MY 2017-2025 GHG and CAFE standards affect 

essentially the same vehicle classes over the same timeframe as this proposal for non-

 

343 77 FR 62623 (October 15, 2012).

344 75 FR 25324 (May 7, 2010).
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GHG emissions standards and gasoline fuel quality. Accordingly, EPA believes it is 

important for the two rulemakings to be coordinated so that manufacturers can develop 

future product development plans with a full understanding of the major regulatory

requirements they would be facing over the MY 2017-2025 time frame.

The Agency would like to highlight two important issues of overlap between 

these two rulemakings: Test fuel and useful life. As explained above, today’s action 

proposes to update EPA’s test fuel to better match in-use fuels, with the change in test 

fuel phased-in from MY 2017-2020 for light-duty exhaust emission compliance. The 

proposal involves several changes to the emissions test fuel specifications, including, 

notably, a 15 percent by volume ethanol content. The current emissions test fuel contains 

zero ethanol. Regarding useful life, we are proposing a longer useful life for some 

vehicles, as described in Section IV.A.7.b, from the current 120,000 miles to 150,000 

miles.

a. Test Fuel

The proposed change in test fuel, if finalized, could have implications for both the 

CAFE and GHG emissions compliance programs, as well as the fuel economy labeling 

program. EPA is committed to the principle of ensuring that the proposed change in test 

fuel would not affect the stringency of either the CAFE or GHG emissions standards, and 

that the labeling calculations would be updated to reflect the change in test fuel.

While NHTSA establishes the fuel economy standards for the CAFE program, 

EPA is responsible for vehicle testing and calculation of fuel economy values used by

manufacturer for compliance with the CAFE standards. Under the Energy Policy and 

Conservation Act (EPCA), limitations are placed on the test procedures used to measure 

fuel economy for passenger cars. For passenger automobiles, EPA has to use the same 

procedures used for model year 1975 automobiles, or procedures that give comparable 

results.346 When EPA has made changes to the FTP or HFET, we have evaluated 

whether it is appropriate to provide for an adjustment to the measured fuel economy 

results, to comply with the EPCA requirement for passenger cars that the test procedures 

produce results comparable to the 1975 test procedures. These adjustments are typically 

referred to as a CAFE or fuel economy test procedure adjustment or adjustment factor. 

Because ethanol has a lower energy content than gasoline, i.e., fewer British 

thermal units (Btus) or joules per gallon,347 and fuel economy is defined in terms of miles 

per gallon of fuel, it is almost certain that the same vehicle tested on a test fuel with 15 

percent ethanol content will yield a lower fuel economy value relative to the value if it 

were tested on the current test fuel with zero ethanol content. For CAFE purposes, the 

existing fuel economy equation for gasoline that has been in use for many years already 

contains an adjustment for the energy content of the test fuel to calculate fuel economy 

 

346 49 U.S.C. 32904(c).

347 EPA estimates that, on average, E85 fuel contains 25-30 percent less energy per gallon than gasoline 

with zero ethanol.
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equivalent to what would have been determined using the 1975 baseline test fuel.348 

Therefore, it is not clear that any further action is necessary to account for the proposed 

change in certification test fuel. Within this equation, however, is a so-called “R-factor” 

to account for the fact that the change in fuel economy is not directly proportional to the 

change in energy content of the test fuel. Although an R-factor of 0.6 has been used 

since 1988, manufacturers have suggested that a higher value may be more appropriate. 

We discuss this issue in a memo to the docket.349 This is a technical issue with the fuel 

economy equation that has been raised in the context of the proposed certification test 

fuel change, but technically it is distinct from the proposed change in test fuel. EPA will 

continue to investigate this issue and if necessary address it as part of a future action. 

EPA is also committed to retaining equivalent stringency for GHG emissions 

compliance associated with the proposed test fuel change. The proposed changes in test 

fuel properties in this rule do not have any appreciable impact on carbon dioxide grams 

per mile levels. This is supported by data from the EPAct study, which show that the 

change in the test fuel have both positive and negative impacts that offset each other and 

that there is no net impact on carbon dioxide grams per mile levels. This is discussed in a 

memo to the docket.

350

 We seek comment on the impact of this proposal on CO2

emissions. Should action to adjust the compliance calculation for the light-duty GHG 

standards become warranted, we would include such changes as a part of a future action. 

EPA expects that there may be a potential impact on manufacturer’s fuel economy

and greenhouse gas testing burden during the Tier 3 phase-in years. Currently, for 

example, manufacturers carry over a considerable amount of previous model year data in 

support of their Fuel Economy Labeling and CAFE/Greenhouse Gas programs. We are 

proposing that Tier 3 compliant vehicles would be required to test on E15 test fuel, and 

thus, manufacturers would normally not be allowed to carry over previous model year 

data from vehicles tested on E0 test fuel. EPA anticipates that such carryover requests 

could be handled during the Tier 3 phase-in years with modifications to EPA’s current 

policy for the use of analytically derived data (see EPA’s fuel economy, CO2, and 

carbon-related exhaust emissions testing regulations at 40 CFR 600.006-08(e) and EPA 

guidance letter CD-12-03 (February 27, 2012) and CCD-04-06, (March 11, 2004351)). 

EPA requests comments on whether there is a need for further reductions in fuel 

economy/greenhouse gas testing burden beyond that allowed by the above EPA guidance 

letters. Any comments supporting the need to reduce fuel economy/greenhouse gas 

 

348 40 CFR 600.113-12(h)(1).

349 Butler, A. (February 2013) Analysis of the Effects of Changing Fuel Properties on the EPA Fuel 

Economy Equation and R-Factor. Memorandum to the docket.

350 Butler, A. (February 2013) Analysis of the Effects of Changing Fuel Properties on the EPA Fuel 

Economy Equation and R-Factor. Memorandum to the docket.

351 EPA Guidance Letters CD-12-03 (Analytically Derived CO2 and Carbon-Related Exhaust Emissions 

(CREE) for Light-Duty Vehicles) and CCD-04-06 (Updated Analytically Derived Fuel Economy (ADFE) 

Policy for 2005 MY and Later), March 11, 2004, is available through the EPA Transportation and Air 

Quality Document Index System at: http://iaspub.epa.gov/otaqpub/.
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testing burden (beyond that allowed by EPA’s policy for the use of analytically derived 

data) should describe one or more specific methods of reducing such testing burden. 

Finally, EPA will need to update the fuel economy labeling calculations in 40 

CFR Part 600 to reflect the proposed E15 test fuel. The current methodology, which took 

effect with the 2008 model year, contains equations that, when applied to test results 

using current fuel (zero alcohol), adjust for an average national impact of ethanol in fuel 

on fuel economy. These equations would need to be revised such that the adjustment 

remains consistent with the actual national use of ethanol in fuel. 

b. Useful Life for GHG Standards

As stated above, EPA is committed to retaining equivalent stringency for GHG 

emissions compliance beginning in MY 2017. In contrast to the proposed Tier 3 test fuel, 

for which we are uncertain as to the effects on GHG emissions, 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 proposing to require a 

longer useful life for GHG emission standards. As this approach may result in additional 

testing burden, we are proposing that manufacturers could optionally certify GHG 

emissions to a 150,000 mile, 15 year useful life.

5. Consideration of Nonroad, Motorcycle, and Heavy-Duty Engine Emissions 

Test Fuel 

As described earlier in Section IV.D.1., we are proposing new specifications for 

the gasoline emissions test fuel used for testing highway vehicles subject to the proposed 

Tier 3 standards. In developing today’s proposal, EPA also considered proposing the 

change in test fuel specifications for other categories of engines, vehicles, equipment, and 

fuel system components that use gasoline. This would 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, 

on-highway motorcycles, and larger heavy-duty gasoline engines. 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 lower level of 

technology, emissions from these engines are potentially much more sensitive to changes 

in fuel quality.

EPA is not proposing to apply 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 emissions test fuel 
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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. EPA requests comment on the implications of 

changing the test fuel for these other categories and whether a different test fuel would be 

more appropriate for these other categories.

6. Consideration of CNG and LPG Emissions Test Fuel

There are currently no sulfur specifications for the test fuel used for certifying 

natural gas vehicles. There is also no sulfur specification in §86.113 for the test fuel used 

for certifying liquefied petroleum gas (LPG) vehicles. The corresponding LPG test fuel 

for heavy-duty highway engines and for nonroad engines in §1065.720 includes an 80 

ppm maximum sulfur specification.

We request comment on the appropriateness of changing §86.113 to reference 40 

CFR part 1065 for both natural gas and LPG test fuels. We further request 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. Changing the sulfur specifications would depend on establishing that 

the new specification is consistent with the range of properties expected from in-use 

fuels.

E. Small-Business Provisions

As in previous vehicle 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 proposed Tier 3 vehicle program, we evaluated the 

environmental need as well as the technical and financial ability of manufacturers and 

others to meet the standards as expeditiously as possible. We believe it is feasible and 

necessary 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 manufacturers and others, we believe that 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 proposing 

several flexibility provisions for small businesses in the vehicle industry to reduce the 

burden that this program could have on them. These proposed provisions are based on 

the recommendations of the Small Business Advocacy Review (SBAR) Panel described 

in Section XIII.C of today’s proposal and include a few additional provisions. 

Small entities generally lack the resources that are available to larger companies 

to carry out necessary research and development and to raise capital for investing in a 

new regulatory program. Small entities are also likely to have more difficulty in 
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competing for any needed engineering and construction resources and lower production 

volume over which to spread their compliance costs. Small entities also tend to have 

limited product lines, which limits their ability to take advantage of the phase-in and 

ABT flexibility provisions in the proposal. As such, we are proposing regulatory

flexibility provisions that would provide additional lead time and reduced testing burden 

for small entities in meeting the proposed Tier 3 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 make any necessary modifications to their product lines. We 

believe that small business regulatory flexibilities could provide these entities with 

additional help and/or time to take advantage of technological developments by other 

parties and to accumulate capital internally or to secure capital financing from lenders, 

and could spread out the availability of any needed engineering resources. We believe 

these provisions will also reduce their overall compliance burden and allow them to more 

easily transition to the new standards in a way that matches their business practices. 

The provisions described below would be available to all small businesses subject 

to the Tier 3 emission standards. The types of companies subject to the Tier 3 emission 

standards include vehicle manufacturers, and two additional categories of businesses that 

are generally referred to as independent commercial importers (ICIs) and alternative fuel 

vehicle converters. As discussed below, the proposed set of flexibilities would also be 

available to manufacturers in these three business categories that sell less than 5,000 

vehicles per year that are subject to the Tier 3 emission standards.

1. Lead Time for Exhaust and Evaporative Emission Standards

As noted above, small businesses have limited resources available for developing 

new designs to comply with new emission standards. In addition, it is often necessary for 

these businesses to rely on vendor companies for technology. Moreover, percentage 

phase-in requirements and declining fleet average standards pose a dilemma for a small 

manufacturer that has a limited product line (e.g., the manufacturer certifies vehicles in 

only one or two test groups). Thus, similar to the flexibility provisions implemented in 

previous vehicle rules, the Panel recommended that EPA allow small businesses the 

following flexibility option for meeting the proposed Tier 3 emissions standards.

EPA is proposing that small businesses (and small volume manufacturers, as 

discussed below) be given additional lead time to comply with the proposed Tier 3 

exhaust and evaporative emission standards. Specifically, we propose to allow small 

manufacturers to postpone compliance with the standards and other Tier 3 requirements, 

including use of the proposed new certification test fuel, until model year 2022. For 

model year 2022 and later, small manufacturers would be subject to the same Tier 3 

exhaust and evaporative requirements as other manufacturers, including moving to the 

declining FTP fleet average NMOG+NOX curve and complying with the fully phased-in

standard of 30 mg/mi, as well as certifying on E15 test fuel. (This approach is similar to 

that in the Tier 2 rule where EPA allowed small manufacturers to wait until the end of the 

phase-in to comply with the Tier 2 standards.) As described earlier in this section, the 

proposed Tier 3 rule has several different phase-in schedules; with the final dates varying 
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from model year 2021 for the new light-duty exhaust PM standards to model year 2025 

for the new light-duty exhaust gaseous pollutant standards. Requiring all small 

businesses to comply with the full slate of Tier 3 requirements in model year 2022 should 

provide sufficient lead time for manufacturers to plan for and implement the technology

changes needed to comply with the Tier 3 standards. 

During the SBAR Panel process, one small entity representative (SER) 

recommended that EPA adopt relaxed exhaust standards for small manufacturers. The 

SER noted that the exhaust emission averaging program being proposed by EPA would 

allow large manufacturers that have many engine families to certify their small, niche 

products at emission levels numerically higher than the standards. Small manufacturers 

that typically do not have more than one or two emission families generally cannot use 

averaging to the same extent because of their limited product offerings. The SER was 

concerned that the high-performance vehicles produced by large manufacturers which 

they compete against would be able to certify at numerically higher levels at less cost 

than the SER would incur. The SER-recommended relaxed NMOG+NOX standards over 

the Federal Test Procedure (FTP) are 125 mg/mi in model year 2020 and 70 mg/mi in 

model year 2025. This is the same general approach that the CARB Board approved for 

small volume manufacturers in LEV III (a relaxed standard NMOG+NOX of 125 mg/mi 

followed by a fully phased-in standard of 70 mg/mi in model year 2025), except that the 

CARB program introduces the relaxed standard and the change in test fuel in model year 

2022. 

As described above, although we are proposing a delay in the Tier 3 requirements, 

EPA is not proposing to relax the fully phased-in standards for the small entities. We 

believe that these standards are technologically feasible and can be readily achieved with 

the additional lead time we are proposing as the technology would have already been 

demonstrated by other manufacturers, in some cases on the very same engines used by 

the small manufacturers. In addition, the compliance costs for many of these vehicles, 

even if higher on an absolute basis, may still be lower on a relative basis given the higher 

average cost of the vehicles. Furthermore, EPA is proposing to allow manufacturers to 

apply for hardship relief (discussed below) on a case-by-case basis. EPA requests 

comment on our proposed approach and whether there is an additional need for the final 

rule to allow small manufacturers to meet relaxed NMOG+NOX exhaust emission 

standards on the FTP over the long term, as suggested by the SER and as reflected in 

action by CARB. 

In light of the CARB Board-approved implementation schedule for small 

manufacturers described above, we also request comment on an option that would not 

provide a permanent relaxed standard for small manufacturers, but would provide a 

temporary relaxed standard matching the California standard from model year 2022 

through 2024. This option would apply to the Tier 3 exhaust emission standards starting 

in 2022, except that a relaxed NMOG+NOX standard of 125 mg/mi would apply in model 

years 2020-2024 for FTP testing. For model years 2025 and later, the standard would be 

the same as for all other manufacturers, or 30 mg/mi. Under this option, small 

manufacturers would have to take some action to reduce emissions in 2022 and could 

postpone meeting fully phased-in Tier 3 standards until 2025. 
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2. Assigned Deterioration Factors

Under EPA’s regulations, manufacturers must demonstrate that their vehicles 

comply with the emission standards throughout the “useful life” period. This is generally

done by testing vehicles at low-mileage and then applying a deterioration factor to these 

emission levels. The deterioration factors are determined by aging new emission control 

systems and then testing the aged systems again to determine how much deterioration in 

emissions has occurred. In order to reduce the testing burden in previous rulemaking, 

EPA has allowed small manufacturers to use deterioration factor values assigned by EPA 

instead of performing the extended testing. A manufacturer would apply the assigned 

deterioration factors to its low-mileage emission level to demonstrate whether it complied 

with the Tier 3 emission standards.

With today’s proposal, EPA proposes that small businesses be allowed the option 

to use EPA-developed assigned deterioration factors in demonstrating compliance with 

the Tier 3 exhaust and evaporative emission standards. In the past, EPA has relied on 

deterioration factor data from large manufacturers to develop the assigned deterioration 

factors for small manufacturers. EPA would expect to follow a similar procedure to 

determine the assigned deterioration factors for the Tier 3 standards once large 

manufacturers start certifying their Tier 3 designs. Given that larger manufacturers 

would begin phasing in to the Tier 3 standards in model year 2017, EPA should have a 

significant set of emissions deterioration data upon which to base the assigned 

deterioration factors for small businesses within the first few years of the Tier 3 program. 

EPA recognizes that assigned deterioration factors need to be determined well in advance 

of model year 2022 in order to provide sufficient time for small businesses to decide 

whether or not to use the assigned deterioration factors for certification purposes.

3. Reduced Testing Burden

Under EPA’s regulations, manufacturers must perform in-use testing on their 

vehicles and demonstrate their in-use vehicles comply with the emission standards. The 

current in-use testing regulations provide for reduced levels of testing for small 

manufacturers, including no testing in some cases. EPA is proposing to continue the 

reduced levels of testing for small businesses under the Tier 3 program. Under the 

reduced testing provisions, manufacturers that sell less than 5,000 units per year would 

not be required to do any testing under the in-use program. Manufacturers that sell 

between 5,001 and 15,000 units per year would be required to test two vehicles per test 

group, but only under the high-mileage conditions specified in the in-use program.

Under current regulations, manufacturers may waive testing for PM emissions for 

light-duty vehicles and trucks, except for diesel-fueled vehicles. Manufacturers are still 

subject to the standards and must make a statement of compliance with the PM standards. 

As described in Section IV.A, EPA is proposing new PM standards and will require 

manufacturers to test for PM emissions for all fuels. Because PM testing requires 

additional test equipment and facilities, the costs incurred for PM testing can be 

substantial, especially for a company selling small numbers of vehicles. Therefore, EPA 

is proposing to continue the waiver for PM testing in the Tier 3 timeframe for small 
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businesses. Small businesses will not be required to measure PM emissions when they

certify to the Tier 3 emission standards. In lieu of testing, small businesses will be 

required to make a statement of compliance with the Tier 3 PM standards. We would 

retain the ability to determine the PM emissions results in confirmatory or in-use testing.

As described in Section IV.C, EPA is proposing new OBD requirements for 

vehicles certifying to the Tier 3 standards. The proposed OBD requirements are the same 

as CARB’s existing OBD requirements. The proposed OBD provisions require 

additional amounts of testing and information that can add significant cost for 

manufacturers if they are not already meeting the CARB OBD requirements. Small 

business vehicle manufacturers tend to comply with the CARB OBD requirements 

because they want to sell in the California market. On the other hand, alternative-fuel 

converters do not generally certify with CARB because of the significant cost burden of 

complying with the CARB OBD requirements. We are therefore proposing that small 

business alternative-fuel converters may continue to comply with EPA’s existing OBD 

requirements (see 40 CFR 86.1806-05) when the Tier 3 standards become effective. 

However, the proposed upgraded OBD requirements would have to be met by small 

entities and ICI’s by the 2022 MY.

Alternative-fueled vehicles, MDPVs, FFVs, and HDVs do not have SFTP 

emissions requirements under the current regulations. As described in Section IV.A, 

EPA is proposing to apply the Tier 3 SFTP standards to all vehicles, including 

alternative-fueled vehicles, MDPVs, FFVs, and HDVs. Because SFTP testing includes 

emission measurement over the SC03 test cycle, which requires additional test facilities 

beyond those needed to run the FTP, the costs incurred for SC03 testing can be 

substantial, especially for companies like alternative fuel converters that sell very low 

numbers of converted vehicles. We are proposing that for the categories of vehicles 

newly subject to the SFTP standards, including alternative-fueled vehicles, manufacturers 

have the option to substitute the FTP emissions levels for the SC03 emissions results for 

purposes of compliance when calculating the SFTP emissions. However, we would 

retain the ability to determine the composite emissions using SC03 test results in 

confirmatory or in-use testing. Because the vehicles being converted to an alternative 

fuel will likely have been tested for SFTP compliance, we expect the SFTP emissions 

should be similarly low, and therefore the added SC03 testing burden is unnecessary.

During the SBAR process, one SER requested that EPA eliminate some of the 

evaporative emission testing requirements for small businesses based on its belief that 

some of the tests may be duplicative. While EPA understands the reasons behind the 

SER’s suggestion, we believe it may be premature to consider such an option in the Tier 

3 rule given the potential impact of the CO2 emission standards on engine and fuel 

system development. Currently, it is generally understood that the 2-day diurnal test 

drives the purge characteristics of evaporative control systems, while the refueling test, 

and to a lesser degree the 3-day test, drive the capacity requirement of evaporative 

canisters. Prospectively, due to expected changes in engine and fuel system designs in 

response to upcoming CO2 emission standard requirements, this may not be the case. 

Therefore, EPA believes it is appropriate to retain all of the evaporative test procedures. 

It can be noted that under current regulations, EPA does allow manufacturers to waive 2-
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day diurnal testing for certification purposes (see 40 CFR 86.1829-01(b)(2)(iii)) and 

perform only the 2-day diurnal test as part of the in-use testing program (see 40 CFR 

86.1845-04(c)(5)(ii)). These provisions would continue in the Tier 3 program. In 

general, EPA is open to changes that reduce test burden while maintaining the 

environmental effectiveness of its programs and could consider changes like those 

suggested by the SER in the future as the impacts of the future regulations on engine and 

vehicle design become clearer. Therefore, EPA requests comment on streamlining the 

current test procedures for small businesses in ways that would still maintain the overall 

effectiveness of the tests.

4. Hardship

EPA is proposing hardship provisions for small businesses subject to the Tier 3 

exhaust and evaporative emission standards. Under the hardship provisions, small 

businesses would be allowed to apply for additional time to meet the 100 percent phasein requirements for exhaust and evaporative emissions. All hardship requests would be 

subject to EPA review and approval. Appeals for such hardship relief would need to be 

made in writing and must be submitted well before the earliest date of potential 

noncompliance. The request would need to identify how much time is being requested. 

It must also include evidence that the noncompliance would occur despite the 

manufacturer's best efforts to comply, and must contain evidence that severe economic 

hardship would be faced by the company if the relief is not granted. The hardship 

provision should effectively provide the opportunity for small businesses to obtain more 

time to comply with the new Tier 3 standards. The existing hardship provisions limit the 

extra time that can be requested to 1 year, but we are proposing that such a limit is not 

needed as part of the Tier 3 hardship provisions.

5. Applicability of Flexibilities

Under EPA’s Tier 2 regulations, EPA provides a number of flexibilities for small 

volume manufacturers (SVMs). The criteria for determining if a company is a “small 

volume manufacturer” is based on the annual production level of vehicles and is based on 

whether the company produces less than 15,000 vehicles per year. Unlike EPA’s current 

small volume manufacturer criteria, the Small Business Administration (SBA) defines 

which manufacturers are small businesses based on the number of employees for vehicle 

manufacturers and annual revenues for ICIs and alternative fuel converters. For example, 

SBA defines a small business vehicle manufacturer as those who have less than 1,000 

employees.

With today’s notice, EPA proposes that all small businesses that are subject to the 

Tier 3 standards and that meet the SBA criteria be eligible for the flexibilities described 

above. Unless otherwise noted, the proposed flexibilities would be available to all small 

business vehicle manufacturers, ICIs, and alternative fuel converters subject to the Tier 3 

standards. In addition, EPA is proposing that manufacturers subject to the Tier 3 

standards which meet a specified sales-based criteria be eligible for the flexibilities 

described above. It is relatively easy for a manufacturer to project and ultimately

determine sales. Determining the annual revenues or number of employees is less 
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straightforward. In the recent rule setting the first light-duty vehicle and truck CO2

emission standards, EPA adopted provisions for small manufacturers based on a sales 

cutoff of 5,000 vehicles per year as opposed to the 15,000 level noted earlier that is used 

in the Tier 2 program. EPA proposes that the small volume manufacturer definition be 

based on the 5,000 vehicle per year level for the Tier 3 program. For purposes of the Tier 

3 rule, the 5,000 limit would be based on a running three-year average of the number of 

light-duty vehicles, light-duty trucks, medium-duty passenger vehicles, and complete 

heavy-duty trucks below 14,000 lbs GVWR. EPA believes the 5,000 unit cut-off for 

small volume manufacturers would include all of the vehicle manufacturers, ICIs, and 

alternative fuel converters that currently meet the applicable SBA definition as well as a 

few additional companies that have similar concerns to small businesses.

EPA requests comment on the issue of extending eligibility for the Tier 3 small 

volume manufacturer provisions to very small manufacturers that are owned by large 

manufacturers but are able to establish that they are operationally independent. EPA has 

established such a provision in the light-duty greenhouse gas (GHG) program.353 EPA 

requests comment specifically on whether a manufacturer who meets the criteria for 

establishing operational independence under 86.1838-01(d) for eligibility for SVM

provisions under the GHG program should be considered to be operationally independent 

and similarly eligible for SVM provisions under the Tier 3 program.

F. Compliance Provisions

1. Exhaust Emission Test Procedures

We are proposing technical amendments to 40 CFR part 1066 as part of the effort 

to migrate test requirements from 40 CFR part 86 for light-duty vehicles and 

measurement of criteria pollutants. The proposed procedures in part 1066 reference large 

portions of part 1065 to align test specifications that apply equally to engine-based and 

vehicle-based testing, such as CVS and analyzer specifications, calibrations, test fuels, 

calculations, and definitions of many terms. The proposed part 1066, as amended, also 

incorporates most of the detailed part 86 procedures.

Current testing requirements related to chassis dynamometers rely 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. This proposal attempts to 

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. We request comment on the range of proposed requirements 

related to these chassis test procedures.

 

353 See 77 FR 62793-62794 and 40 CFR 86.1838-01(d)
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Proposed revisions to part 1066, and adjustments from part 86, include the 

following:

 Clarification of regulatory requirements.

 Correction of typographical errors.

 Migration of mass-based emission calculations from part 86 to part 1066.

 Introduction of a new NMOG calculation.

 Revision of 40 CFR 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.

We are proposing 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 proposed procedures include improvements that will reduce 

lab-to-lab and test-to-test variability.

We are proposing to eliminate separate sampling of Bag 2 of the FTP test cycle to 

allow for an increase in sampled PM mass. The proposed alternative approach is to 

sample Bags 1 and 2 of the FTP on a single filter, and sample Bags 2 and 3 of the FTP 

onto a second filter. This will generally involve simultaneous sampling of Phase 2 onto 

two separate filters. As an additional alternative, manufacturers may run cold and hot 

UDDSs without simultaneous sampling of the cold UDDS Phase 2, or to sample Bag 1, 

Bag 2, and Bag 3 on a single filter. Manufacturers choosing any of these options must 

still run a separate three-bag test for evaporative emission testing. We request comment 

on continuing to allow sampling under the traditional FTP methodology of a bag or filter 

per test phase (3 phases in total) instead of these proposed new methods. We also request 

comment on the appropriate transition to using the new sampling and calculation 

methods.

We are proposing to revise the chassis dynamometer specifications in part 1066 

by removing the maximum roll diameter and by requiring speed and force measurements 

at a minimum frequency of 10 hertz (Hz). Some manufacturers may be interested in 

testing with nonstandard dynamometer configurations, such as new flat-track 
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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).

Part 1066 relies extensively on calculations involving physical parameters to 

calculate emission rates and perform various calibrations and verifications. As reflected 

in the current version of 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 would allow us to 

more carefully and appropriately specify precision values for various measured and 

calculated parameters. This would also simplify calculations, facilitate review of results 

from different laboratories, and help with communications regarding any round-robin 

testing that might occur. Note that we are not contemplating converting emission 

standards to SI units. We request comment on completing the migration toward SI units 

in part 1066. In particular, we request comment on adding vehicle speed specifications in 

meters per second in addition to the current specification in miles per hour (or kilometers 

per hour for motorcycles). Specifying vehicle speeds to the nearest 0.01 m/s would allow 

for equivalent vehicle operation relative to current drive schedules. The cycle validation 

criteria would be based on a speed tolerance of ±1.0 m/s rather than ±2 mph (or rather 

than the proposed change to a ±2.0 mph tolerance). This is not a direct unit conversion, 

but is calculated based on the stated precision and rounding allowance to provide a 

comparable degree of variability in vehicle speeds.

We are proposing to phase in the requirements to use part 1066 test procedures for 

certifying all sizes of chassis-tested vehicles. For this phase-in approach, all aspects of 

part 1066 related to PM testing must be met at the start of MY 2017 for vehicles 

certifying to the PM standards. All other aspects of part 1066 must be met starting with 

the certification of all MY 2022 vehicles.

As described in Section IV.D, we are proposing new test fuel specifications for 

E15 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 request 

comment on further revising 40 CFR part 86 to refer to the test fuel specifications in part 

1065 for natural gas and liquefied petroleum gas. 

The proposal also includes various technical amendments to 40 CFR part 1065. 

The proposed technical amendments have no effect on the stringency of the regulations. 

These revisions 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 proposing to update 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.E.3 describe how this applies for 
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demonstrating that vehicles meet the Tier 3 PM standards. We are also proposing to 

allow 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 proposing to allow 

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 would not approve a manufacturer’s request to omit 

measurement of these emissions during a selective enforcement audit.

The regulations currently allow 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 would comply with the NMOG+NOX standards while 

exceeding the formaldehyde standards. We are therefore proposing to continue this 

waiver practice, such that manufacturers of Tier 3 vehicles do not need to submit 

formaldehyde data for certification.

We are also requesting comment on rearranging the default testing specification 

for certifying vehicles to evaporative emission standards, as described in Section IV.C. 

This would involve requiring manufacturers to perform testing with the two-day test 

sequence, while making the three-day test sequence optional.

3. Miscellaneous Provisions

The following additional certification and compliance provisions are included in 

the proposed rule:

 The certification practice for assigned deterioration factors which are 

available for both small volume manufacturers and small volume test groups 

has matured significantly since it was first adopted. We are proposing to 

revise §86.1826 to more carefully reflect the current practice. For example, 

the regulations specify 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 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 

proposing to address this by specifying that the rounding protocol described in 

40 CFR 1065.20(e) applies, unless specified otherwise. We are not proposing 

to change all the references in part 86; rather, we are proposing to define 

“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 
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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 Part 85, Subpart P. The standards which apply to the vehicles 

imported depend, in part, on the model year of the vehicle being imported. 

Therefore, vehicles imported by ICIs in the future could be subject to the 

proposed Tier 3 standards and the proposed regulations reflect the application 

of the Tier 3 standards to ICIs. Because all existing ICIs are small-volume 

manufacturers, the Tier 3 standards would not apply until 2022 at the earliest. 

In addition, the certification practices for ICIs have matured significantly 

since they were first adopted. EPA is proposing two changes to update the 

regulations affecting ICIs. First, the proposed provisions would require 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 such test equipment for ICIs in the 

future. In cases where an ICI can demonstrate that they will incur a 

substantial increase in compliance costs, the proposed regulations include a 

provision that allows EPA to approve requests, on a case-by-case basis, to 

allow testing on other types of dynamometers until the ICI is able to comply 

with the proposed electric dynamometer requirements. Second, we are 

proposing to incorporate into regulation that ICIs be allowed to use a specific 

set of reduced testing requirements for up to 300 units 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.354 Instead of running a full set of 

emission tests, the reduced testing requirements would allow ICIs to run an 

FTP for exhaust emissions, a highway fuel economy test, and a shortened onehour evaporative emission tests for hot-soak and diurnal emissions that 

applied prior to the current enhanced evaporative emission test procedures. 

We do not believe the proposed changes should have any significant cost 

impacts on ICIs. Most of the ICIs have electric dynamometers or can upgrade 

them 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 otherwise could be required. 

 We are proposing to adopt CARB’s onboard diagnostic requirements for all 

light-duty vehicles, light-duty trucks, and heavy-duty vehicles, as described in 

Section IV.C.5.d. We currently allow for this as an option, but almost all 

manufacturers do this already to avoid certifying multiple systems. Now that 

we are adopting evaporative provisions that depend on California’s regulatory

 

354 See 40 CFR 86.106-96(a) and Enclosure 2 to EPA Guidance letter CCD-02-04, February 6, 2002.
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specifications and we are making efforts to adopt a single, national regulatory

program, we believe this is an appropriate step. This proposal includes heavyduty vehicles above 14,000 lbs GVWR, though these vehicles would not need 

to meet the new requirements related to leak testing. These changes would 

apply starting in model year 2017 for vehicles subject to Tier 3 standards. 

The changes apply directly for heavy-duty vehicles above 14,000 lbs GVWR, 

since all those vehicles are already certified based on CARB’s regulations. In 

the case of alternative fuel conversions, we are proposing to continue to apply

the requirements of 40 CFR 86.1806-05.

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

The fuel on which a vehicle will be operated in-use and tested is considered an 

integral part of the vehicle 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 the required 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 in-use would 

not 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 EPA’s proposal, in-use fuel would transition from an average sulfur level of 30 

ppm required by Tier 2 to a new average level of 10 ppm under Tier 3. The proposed 

sulfur requirements would be average standards. Thus, even after the transition to the 10 

pm average sulfur level, vehicles might still encounter sulfur levels during in-use 

operation 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 proposing some modifications to the IUVP testing process 

based in part on what was allowed under the Tier 2 program. Tier 3 vehicles tested in the 

IUVP would 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 

failed the NMOG+NOX standard for the FTP or HFET cycle during the initial round of 

testing, manufacturers would be allowed to perform a sulfur cleanout procedure before 

repeating the FTP or HFET. For the sulfur cleanout, manufacturers would be allowed to 

perform up to two US06 cycles. The measured US06 cycle and a preconditioning US06 
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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 approval by EPA. Following the sulfur cleanout 

procedure, the manufacturer would prep and soak the vehicles and then repeat the FTP 

and HFET tests. If a manufacturer chose to perform the sulfur cleanout procedure, it 

would be required to submit evidence that the vehicle encountered high sulfur levels in 

the fuel just prior to emission testing. This would 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 was operating on fuel containing 15 ppm or higher 

sulfur levels in the recent past, only the emission results of the tests following the 

cleanout procedure would be used for purposes of determining emission compliance and 

whether to enter the in-use compliance program (IUCP). 

The proposed rule includes the changes to the IUVP testing described above for 

light-duty vehicles and MDPVs. The changes to IUVP testing are not applicable to 

heavy-duty vehicles tested in the IUVP program. Also, as described in Section IV.D, we 

are proposing to incorporate leak testing into the IUVP test protocol. We are not 

proposing additional changes to the overall IUVP test program. 

V. Proposed Fuel Program

Under today’s Tier 3 program, we are proposing reductions in gasoline sulfur 

levels nationwide. These standards would 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. Section V.A provides an overview of the fuel program and how we 

arrived at the proposed gasoline sulfur standards. Section B presents our assessment of 

the impacts the proposed fuel program would have on stationary source permitting and 

our conclusion that the proposed refinery lead time is adequate. Section V.C contains our 

proposed standards for denatured fuel ethanol. In Section V.D, we introduce and seek 

comment on possible options for regulating gasoline-ethanol blends intended for flexible 

fuel vehicles. Section V.E presents the proposed program flexibilities including the 

averaging, banking, and trading (ABT) program as well as small refiner and small 

volume refinery provisions. Section V.F lays out the compliance provisions for the 

proposed Tier 3 gasoline program. Finally, Section V.G presents our statutory authorities 

for lowering gasoline sulfur. As a result of these proposals, we have to amend certain 

existing provisions in the current Tier 2 requirements at 40 CFR part 80. We are not 

reopening Tier 2 and our proposed amendments should not be construed as a reopener.
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A. Proposed Tier 3 Gasoline Sulfur Standards

1. Overview

a. History of 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.6, 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 Program355 and is proposing to take further action 

under the proposed 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 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-ppm annual average and 80-

ppm per gallon cap) was required beginning in 2006. Due to extensions provided for 

some refineries under the ultra-low sulfur diesel program, final compliance for all U.S. 

refineries was January 1, 2011. The Tier 2 gasoline sulfur program also had an ABT 

program that allowed companies to generate credits for implementing the required 

changes earlier than required and allowed ongoing flexibility to meet the 30-ppm 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

We are proposing to lower today’s gasoline sulfur standards under 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 impair to a significant degree the emissions control 

 

355 67 FR 6698 (February 10, 2000).
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device or systems on the vehicles subject to the proposed Tier 3 standards. For more on 

our legal authority to set gasoline sulfur standards, refer to Section V.G.

As explained in Section IV.A.6, robust data from many sources shows that 

gasoline sulfur at current levels (i.e., around 30 ppm on average) continues to degrade 

vehicle catalytic converter performance during normal operation. The most significant 

problem is for NOX. Today’s proposed NMOG+NOX vehicle emission standards, an 80 

percent reduction from current Tier 2 standards, would not be possible without the 

gasoline sulfur controls we are proposing today. Tier 3 vehicles must achieve essentially 

zero warmed-up NOX emissions to comply and 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. 

Reducing gasoline sulfur would also help reduce emissions of pollutants that 

endanger public health and welfare from vehicles already on the road today. For the Tier 

2 rule, we had data that showed benefits of reducing gasoline sulfur, but little to no data 

existed for sulfur levels below 30 ppm that we could use to project continued emission 

reductions. Since then, we have tested a wide range of Tier 2 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 ultra-low 

sulfur gasoline. As explained in more detail in Section III.B, lowering average gasoline 

sulfur from 30 to 10 ppm would result in approximately 280,000 less tons of NOX and 

40,000 less tons of VOC. The projected in-use emission benefits would occur almost 

immediately in 2017 when the Tier 3 gasoline sulfur standards take effect. 

c. Summary of Proposed Tier 3 Fuel Program

Under today’s Tier 3 fuel program, we are proposing that gasoline and any

ethanol-gasoline blend contain no more than 10 ppm sulfur on an annual average basis 

beginning January 1, 2017. Similar to the Tier 2 gasoline program, the proposed Tier 3 

program would apply to gasoline in the United States and the U.S. territories of Puerto 

Rico and the Virgin Islands, excluding California. The program, when finalized, would 

result in gasoline that contains an average of two-thirds less sulfur than it does today. We 

are proposing a three-year delay for small refiners and small volume refineries. Eligible 

small refining entities, described in more detail in Section V.E.2, would have until 

January 1, 2020 to comply with the new sulfur standards. 

We are proposing an ABT program that would allow refiners to optimize their 

investment strategies to enable reduction in capital and compliance costs. Refiners and 

importers overcomplying with the 10-ppm standard beginning January 1, 2017 could 

generate standard credits that could be used internally, banked, or traded to other 

companies. We are also proposing an early credit program that would allow refiners and 

importers to spread out their investments over time to allow for an orderly transition. 

Starting January 1, 2014, refiners and importers taking steps to reduce gasoline sulfur 

below the current 30-ppm standard could generate early credits that could be used to 

postpone final investments for up to three years. For a more detailed discussion of the 
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proposed ABT program, refer to Section V.E.1. As a result of the early credit program 

and notwithstanding the proposed delay offered to small refiners and small volume 

refineries, we anticipate considerable reductions in gasoline sulfur levels prior to 2017, 

with final refinery steps to get to 10 ppm occurring on or before January 1, 2020. 

We are proposing to either maintain the current 80-ppm refinery gate per-gallon 

cap and 95-ppm downstream per-gallon cap or lower them to 50 and 65 ppm, 

respectively. We also evaluated and are seeking comment on the potential of lowering 

these caps to 20 ppm and 25 ppm, respectively. There are advantages and disadvantages 

associated with the various sulfur cap options (explained in more detail in Section 

V.A.3), but under all the proposed options, we believe that the stringency of the 10-ppm 

annual average standard would result in reduced gasoline sulfur levels nationwide. 

A summary of the proposed Tier 3 gasoline sulfur standards is presented below in 

Table V-1. Domestic refiners and gasoline importers would be subject to both the 10-

ppm annual average sulfur standard and the refinery gate per-gallon cap, when finalized. 

Gasoline in the distribution system (i.e., at terminals, retail stations, etc.) would be 

subject to the downstream per-gallon cap. For more information on how we arrived at 

the proposed sulfur standards, refer to Sections V.A.2 and V.A.3.

Table V-1 Proposed Tier 3 Gasoline Sulfur Standards

Cap Option 1 Cap Option 2

Limit Effective Limit Effective

Refinery annual average standard 10 ppm January 1, 2017a10 ppm January 1, 2017a

Refinery gate per-gallon cap 80 ppm Already 50 ppm January 1, 2020

Downstream per-gallon cap 95 ppm Already 65 ppm March 1, 2020 

a Effective January 1, 2020 for eligible small refiners and small volume refineries.

d. 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.A). Based on information 

gathered from numerous stakeholder meetings, discussions with vendor companies that 

provide the gasoline desulfurization technologies, as well as the results from our refineryby-refinery modeling, we believe it is technologically feasible at a reasonable cost for 

refiners to meet the proposed sulfur standards in the lead time provided. A summary of 

our feasibility analysis is presented below. For more on our fuels feasibility assessment 

and refinery modeling, refer to Chapters 4 and 5 of the draft RIA. 

Gasoline desulfurization technologies are well known and readily available. 

Many technologies were demonstrated under Tier 2 and have been further demonstrated 
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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.356 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.357 Beijing, China also recently introduced a 

10-ppm sulfur limit for gasoline.358 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 

in order to maximize gasoline production. Because the FCC unit is responsible for nearly 

all the sulfur that ends up in gasoline, many U.S. refineries face a bigger challenge in 

achieving 10-ppm gasoline sulfur levels. Nevertheless, these international fuel programs 

(along with California) provide evidence that advanced gasoline desulfurization 

technologies have been deployed and are readily available to comply with the proposed 

Tier 3 fuel program.

When considering the proposed Tier 3 sulfur standards, refineries can be grouped 

into three general categories based on their current post-Tier 2 refinery configurations: 

those without an FCC unit, those hydrotreating the gasoline stream coming from their 

FCC unit (i.e., postreating)359, and those hydrotreating their FCC feed (i.e., pretreating). 

Most refineries without FCC units would not need to do anything to meet the proposed 

Tier 3 sulfur standards. Refineries equipped with FCC units that invested in an FCC 

postreater under Tier 2 would likely just need to revamp (i.e., renovate) their existing unit 

for a modest cost. Refineries that only have an FCC pretreater would meet the Tier 3 

sulfur standards by either revamping their existing pretreaters (perhaps also cutting the 

heavy portion of FCC naphtha into the diesel pool) or invest in a grassroots FCC 

postreater. Our refinery-by-refinery modeling suggests that 29 refineries would not need 

to make any capital changes, 66 would need to revamp their existing FCC postreaters, 

and 16 would need to add grassroots postreaters (we did not model any undercutting of 

 

356 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.

357 Hart Energy Consulting. (2011). International Fuel Quality Center: 2011 Worldwide Fuel Specifications 

358 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

359 Some of them may also have an FCC pretreater.
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heavy FCC naphtha into the distillate pool).

360

 Refiners that need to install a new 

postreater would have to make the largest desulfurization investments under Tier 3, 

typical of many of the refinery investments made under Tier 2. For more on our 

estimated sulfur control costs, refer to Section VII.B. 

We believe that the choice of technology for each refinery is fairly insensitive to 

capital cost assumptions. Revamping an existing FCC postreater will almost always be 

the preferred compliance path if it is available. The majority of refineries only have an 

existing FCC postreater, so revamping it will be the preferred choice, given the much 

higher capital costs associated with adding grassroots FCC pre or postreaters. The 16 

refineries we project would add grassroots postreaters do not have existing postreaters 

that could be revamped. As a result, their choices are limited to revamping their existing 

pretreater or installing a grassroots postreater. We believe based on conversations with 

industry technology vendors and engineering firms that installing a grassroots postreater 

would be more likely for these refineries, because revamping their pretreater would still 

incur a significant capital cost and would reduce compliance flexibility. Thus, in the 

refinery-by-refinery analysis performed by EPA for this proposal, higher capital costs 

(either directly or thru a higher ROI) would be unlikely to alter the selection of pretreater 

versus postreater control technology. Higher capital costs would likely impact both 

technology options proportionally with no overall effect.

We have built in a number of flexibilities that will reduce the compliance burden 

for refiners. In particular, coupling the proposed 10-ppm annual average sulfur standard 

with refinery gate and downstream per-gallon caps should continue to allow for batch-tobatch variability, refinery upsets, and turnarounds while still maintaining the overall air 

quality benefits of the program. For more information on the applicable per-gallon sulfur 

caps, refer to Section V.A.3. 

We are also proposing an ABT program that would allow refiners to spread out 

their investments over time and achieve compliance in the most cost-effective manner. If 

some refineries either comply with the 10-ppm standard earlier than required, or reduce 

sulfur partway toward 10 ppm early, this would allow other refineries to delay 

compliance for a finite period through the use of early credits. The ABT program would 

also allow for ongoing company averaging. This would allow some refineries to stay

slightly above the standard at the expense of other refineries over complying, resulting in 

the most cost-effective mechanism for meeting the 10-ppm annual average standard. For 

more information on the proposed ABT program, refer to Section V.E.1. Finally, our 

Tier 3 gasoline sulfur program, when final, would allow three years of additional lead 

time 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). As a group, we believe that these 

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 refineries 

additional lead time would allow them more time to invest in desulfurization technology, 

 

360 Our in-house refinery modeling considers 111 operational refineries producing non-California gasoline. 
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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. For more on the proposed provisions for 

small refiners and small volume refineries, refer to Section V.E.2. 

The proposed Tier 3 rulemaking should not adversely affect the supply of 

gasoline in the U.S. This judgment is based on a review of both gasoline and diesel fuel 

supply when the Tier 2 gasoline sulfur and ultra-low sulfur highway and nonroad diesel 

rules were phasing in between 2003 and 2011. At the end of this time period, the U.S. 

gasoline and diesel fuel markets were increasingly being supplied by U.S. refiners, 

instead of by imports, compared to the beginning of this time period. Most striking is 

that the more stringent ultra-low sulfur diesel fuel standards showed the largest shift as 

U.S. refiners not only began to supply more of the U.S. diesel fuel market, but became 

net exporters of diesel fuel. For more on our fuel supply assessment, refer to Section 5.3 

of the draft RIA.

2. Proposed Annual Average Sulfur Standard

In the subsections that follow, we lay out our rationale for proposing a 10-ppm 

average standard, our assessment of how the proposed ABT program would help with 

compliance, and our conclusion that the proposed lead time is adequate. In the following 

section, we explain our rationale behind the proposed sulfur caps and seek comment on 

potential alternatives. 

a. Appropriateness of Proposed 10-ppm Sulfur Standard

As explained in Section IV.A.6, 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.361 To protect the precious metal 

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 

 

361 Together, the streams from the reformer and isomerization units account for approximately one-third of 

gasoline. 
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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. 

While further reducing sulfur in gasoline will continue to reduce vehicle 

emissions, our emissions analysis shows that a 10-ppm annual average is sufficient to 

enable vehicles to reach the proposed Tier 3 standards. Moreover, for the following 

reasons, reducing sulfur further below 10 ppm becomes increasingly difficult and costly. 

First, 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. Second, 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. Third, 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 it into a widely varying product slate to match available markets. Those 

processing heavier, sour crudes would have a more challenging time reducing gasoline 

sulfur under the proposed Tier 3 program. As explained earlier, refineries have different 

sulfur levels in their non-FCC streams based on their feedstocks and configurations. 

Those with higher sulfur levels in other refinery streams would 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. 

As such, it can be less costly per gallon for some larger refineries to get down to 10 ppm 

than for smaller refineries, as discussed in Chapter 5 of the draft RIA. As a result, under 

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 to be 5 ppm, 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 below 5 ppm. As discussed 

in Chapter 5 of the draft RIA, to estimate the costs for a 10-ppm annual average standard 

where some refineries stay above 10 ppm, we also estimated the costs for refineries to get 

down to 5 ppm. To do so, we estimated that sulfur control costs would increase by at 

least 50 percent compared to the proposed 10-ppm standard, which is over two times 

more costly per ppm-gallon of gasoline sulfur reduced. This 5-ppm cost assessment is 

reasonable for those refineries that would likely generate credits under a 10-ppm average 
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standard as these refineries are most likely in the best position for achieving such low 

sulfur levels. However, were we to actually assess the costs of a 5-ppm standard, at least 

some of these refineries would likely have additional costs for controlling the sulfur in 

other gasoline blendstocks, and we would likely apply a higher overdesign factor to 

account for industry-wide compliance at 5 ppm. More detailed refinery information may

be needed for such an analysis but, for the more challenged refineries, a 5-ppm standard 

could potentially be cost prohibitive. A 5-ppm standard would also introduce further 

costs to address the contribution to gasoline sulfur from gasoline additives, transmix, 

ethanol denaturants, and contamination in the distribution system. Therefore, a 10-ppm 

annual average standard appears to be the point which properly balances feasibility with 

costs. Also, for these reasons, EPA believes that a viable ABT program is important to 

the success of the proposed Tier 3 fuels program (explained in more detail in Section 

V.A.2.b).

Finally, as discussed in Section IV.A.6, reducing sulfur below 10 ppm would 

further reduce vehicle emissions and allow the proposed Tier 3 vehicle standards to be 

achieved more easily. However, we believe that a 10-ppm average standard will be 

sufficient to allow vehicles to meet the proposed Tier 3 standards. The level of the Tier 3 

standards was considered in light of a 10-ppm average sulfur level for gasoline. If we 

were to consider lowering sulfur further, we would then also have to consider reducing 

the vehicle standards further. Given the challenges associated with sulfur reductions 

below 10 ppm as discussed above, we do not believe this would be appropriate. 

b. How Would the Proposed ABT Program Assist with Compliance?

As described more fully in Section V.E.1, we are proposing an ABT program that 

would reduce the average compliance burden for gasoline producers and importers. This 

program would permit the generation of credits by refineries that reduce their annual 

average sulfur level below 10 ppm, and transfer of these credits to other refineries to 

reduce or eliminate their need to make capital investments to meet the 10-ppm standard. 

The ABT program would thus provide refiners with multiple approaches to compliance, 

and each could choose the approach that minimizes their costs.

We modeled an ABT program to estimate how it would affect compliance. As 

described in more detail in Section VII.B.4, our modeling determined the lowest cost 

approach on a refinery-by-refinery basis under two scenarios: an idealized scenario 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. Today a significant fraction of 

Tier 2 sulfur credits are transferred within companies, but there is still a considerable 

amount of inter-company trading occurring.362 Thus, assuming no trading between 

companies is a conservative assumption and the real impact is likely to be somewhere in 

 

362 Based on Tier 2 sulfur compliance data, of the 26 companies that obtained sulfur credits in 2010, eight 

obtained credits only from their own company, and another five obtained credits both from their own 

company and from other companies. The remainder obtained credits only from other companies.
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between the two scenarios. Table V-2 describes how compliance would be affected 

under these two scenarios.

Table V-2 Impacts of Nationwide ABT Program on Compliance

ABT with 

nationwide credit 

transfers

ABT with intracompany credit 

transfers

Number of refineries that generate credits 46 18

Number of refineries that consume credits 25 8

Number of refineries that neither generate 

nor consume credits

40 85

Total modeled refineries 111 111

Based on our ABT modeling, we believe that a significant number of refineries 

would take advantage of the opportunity to generate or use credits, thus lowering their 

compliance burden under the proposed 10-ppm annual average standard. For a more 

complete discussion of our analysis of the proposed ABT program, refer to Chapter 5 of 

the draft RIA.

c. Adequacy of Proposed Refinery Lead Time

Given the complexity of gasoline refining, numerous planning and action steps 

would be required for refiners to complete the refinery changes needed to comply with 

the proposed Tier 3 sulfur standards. The steps required to implement these changes 

include: the completion of scoping studies, financing, process design for new or 

revamped refinery units or subunits, permitting, detailed engineering based upon the 

process design, field construction of the gasoline sulfur reduction facilities, and start-up 

and shakedown of the newly installed desulfurization equipment.

We conducted a thorough lead time analysis in which we sequenced the estimated 

time to complete scoping studies, process design, permitting, detailed engineering, field 

construction, and start-up and shakedown in advance of production based upon the 

methodology used in our recent gasoline and diesel rules.

For the proposed Tier 3 gasoline sulfur program, we estimated refinery lead times 

step-by- step for the construction of new grassroots FCC postreaters and the revamp of 

existing pre and postreaters. For each refinery project type, we estimated lead times for 

scoping studies, process design, permitting, detailed engineering, field construction, and 

start-up and shakedown. Estimated required lead times for scoping studies are six 

months. Process design ranged from six months for desulfurization equipment 

revamping to nine months for a grassroots postreater. It is during the process of 

performing their scoping studies and process design analysis that refiners would complete

their permit applications. 

Based on discussions with refiners, a review of the permitting experience for Tier 

2 and our current analysis, we estimated that permitting for desulfurization equipment 

revamping and the construction of a grassroots postreater would take 9 months. 
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However, we estimated the overall lead-times for Tier-3-related revamps to be 

considerably shorter, as described below. The estimates for permitting time are 

consistent with those of EPA’s Office of Air Quality Planning and Standards (OAQPS) 

and our regional offices, both of which have engaged in extensive dialog with potentially

affected parties. A discussion of the permitting implications of Tier 3 is contained in 

Section V.B of the preamble. Detailed engineering efforts were estimated to require six 

months for desulfurization equipment revamping and nine months for grassroots 

postreaters. Field construction was estimated to require six months for revamped preand postreaters and 12 months for grassroots postreaters. Start-up and shakedown 

processes were estimated to require six months for revamped FCC treaters and 9 months 

for grassroots postreaters. There is some degree of overlap among each of these steps as 

shown in Table V-3.

To allow refiners to complete all these different steps and comply with the 10 

ppm average gasoline sulfur standard, assuming the Tier 3 proposal were to be finalized 

by the end of 2013, we would be providing three years of lead time. In addition to the 

three years of lead time, the proposed rulemaking also provides additional flexibility

provided by the ABT program, small refinery delays, and hardship provisions. To 

support this timeline, we conducted several analyses of the expected refinery lead time 

requirements associated with the proposed Tier 3 standards and found that refinery 

operators would have more than adequate time to implement the required refinery

charges. A justification for proposed timeline appears below.

Complying with Tier 3 is expected to involve some grassroots FCC postreaters, 

but mostly we believe that refiners will revamp existing FCC postreaters. Revamping of 

existing FCC postreaters can be accomplished in approximately 2 years, or less (See

Table V-3). Grassroots FCC postreaters are expected to require on average about threeyears to install and start-up (See Table V-3). In comparision to FCC pretreaters, 

hydrocrackers and distillate hydrotreaters, FCC postreaters are much less costly, low 

pressure units that take less time to scope out, require shorter lead times for ordering the 

equipment, and less time to install. Furthermore, the grassroots FCC postreaters to be 

installed for Tier 3 are expected to be in a moderate to light desulfurization service 

because the refineries they will be installed in will already be complying with Tier 2 

using an FCC pretreater. FCC naphtha from a refinery with an FCC pretreater is 

expected to only contain about 100 ppm sulfur. To comply with Tier 3, refiners installing 

these grassroots FCC postreaters would only need to desulfurize the FCC naphtha down 

to 25 ppm (about a 75% reduction). In comparison, a single-stage FCC postreaters would 

have to desulfurze FCC naphtha from as high as 2400 ppm sulfur down to 25 ppm, a 99% 

sulfur reduction. The more moderate desulfurization service of the grassroots FCC 

postreaters needed to comply with Tier 3 would be expected to streamline the scoping 

and design work. 
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Table V-3 Anticipated Compliance Timelines

Months

0-

3

3-

6

6-

9

9-

12

12-

15

15-

18

18-

21

21-

24

24-

27

27-

30

30-

33

33-

36

36-

39

39-

42

42-

45

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

It is useful to compare the proposed lead time for Tier 3 to what was provided for 

Tier 2. In the case of the Tier 2 standard, we provided a three-year lead time along with 

an ABT program and other flexibilities to ease compliance. Refiners, though, 

commented that the three year timeline that we provided was not enough time. For the 

Tier 2 analysis, we assumed that refiners would solely install low-pressure FCC 

postreaters, which we believe could be scoped out, designed, installed and started up 

within a 3 year time period. However, many refiners complied with Tier 2 by installing 

high-pressure FCC pretreaters which require long lead times for the procurement of the 

required equipment. Furthermore, those refiners that did not install high-pressure FCC 

pretreaters instead installed grassroots FCC postreaters, many of which were designed for 

severe desulfurization service. An additional difference between Tier 3 and Tier 2 is that 

for Tier 3 we expect the installation of only 16 grassroots units, along with many

revamps, but for Tier 2 virtually all refiners installed both grassroots FCC pretreaters and 

postreaters. The demands on the desulfurization vendors for scoping studies, and on the 

E & C industry for design and construction, and on the refiners to train their operations 

staff and start up the new units, was a lot greater for Tier 2 than what we would expect 

for Tier 3. The total estimated investment cost for Tier 2 versus Tier 3 also highlights the 

difference in investment demands 

The total investment for Tier-2 desulfurization processing units was estimated to 

be about $6.1 billion, while the total investment for Tier-3 desulfurization processing 
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units is estimated to be about $2.1 billion. This simple comparison helps to illustrate that 

the proposed Tier 3 would be easier for refineries to obtain necessary permits, secure 

engineering and construction (E&C) resources, install new desulfurization equipment and 

make all necessary retrofits to meet the proposed sulfur standards. 

We assessed the permitting situation in more detail working in conjunction with 

the Office of Air Quality, Planning and Standards (OAQPS). Since the permitting 

process has little impact on the overall cost of compliance with Tier 3, it is an issue

primarily in terms of its potential impact on the time needed to complete the necessary

refinery modifications. On a refinery-by-refinery basis, we provided OAQPS estimates 

of the additional heating demands for the new and revamped units per the desulfurization 

vendor submissions. OAQPS was able to project which refineries would likely trigger 

NOx, particulate matter and greenhouse gas emission permitting limits, which would 

likely lengthen the permitting process as refiners would need to offset the projected 

emission increases. As it turns out, only 2 of the 16 refineries which are projected to 

install grassroots units were projected to exceed particular permitting limits, and these 

solely did so based on the most conservative assumption that each would produce all the 

additional hydrogen on site using hydrogen plants (as opposed to using existing 

reforming capacity) and produce the electricity on site, to satisfy the needs of the new 

desulfurization equipment. When we provided a second heat demand estimate to 

OAQPS which assumes that refiners purchase their hydrogen and electricity from third

parties, none of the refineries which we projected would install grassroots units was 

projected to have emission increases which would require offsets. Thus, many of the 

grassroots units that we project would be installed may end up with a streamlined 

permitting process. We seek comment on our estimates of the number of refineries that 

may trigger the need for new permits and the length of time necessary to obtain the 

various types of permits that may be required once the refiner applies for them.

The various flexibilities that the proposed Tier 3 rule provides to refiners provide 

refiners additional time for complying. These flexibilities include the ABT program, the 

small refiner delay provisions and the hardship provisions. The ABT program allows a 

refiner, either within its own company or by purchasing credits on the open market, to 

delay higher investment cost investments, such as the investments in grassroots FCC 

postreaters, which would provide additional lead time for installing these units. This 

would occur if refiners would reduce the sulfur levels of their gasoline through 

operational changes or revamps of their existing FCC pretreaters and postreaters when 

the ABT Program begins in 2014. Potentially every refinery with either an FCC 

pretreater or an FCC postreater may be capable of generating early credits. Furthermore, 

we project that 66 refineries would revamp their existing FCC postreaters to comply with 

Tier 3. Since revamps can be completed within two years or less, these refiners could 

potentially begin generating early credits during 2016, or before if refiners begin each of 

these revamps in early 2014. During the period between 2014 and 2017, these refineries 

which reduce their gasoline sulfur levels below that required by Tier 2 would generate 

credits. Refineries with higher cost capital investments, such as the grassroots FCC 

postreaters, could then delay making those investments through the purchase of credits. 

We estimate that sufficient credits could be genereated early to allow many of these 

refineries to delay compliance until as late as 2020. The quantitative early credit analysis 
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that we conducted showed that if refiners with an existing pretreater or postreater would 

generate early credits by lowering their gasoline sulfur down to 20 ppm starting in 2014 

and if revamps were started up in 2016, one year before the program start date, that 

almost 6 times more credits would be available to offset the early credit demand by the 

refiners installing grassroots postreater units, assuming that they start up those units in 

2018. Even if all grassroots postreaters were assumed to not start up until 2020, there 

would be almost 4 times more early credits available to those refiners installing 

grassroots postreaters assuming that the same early credit generation scenario would 

occur.

Additional flexibility is also provided by the small refineries provisions which 

delays compliance by the refineries that refiner less than a net of 75,000 barrels of crude 

oil per day until 2020. Three of the 16 FCC postreater grassroots units that we project 

will be installed would be by small refineries. However, small refineries could also 

decide to comply early and generate credits starting as early as 2014. 

As in previous fuel programs, we are proposing hardship provisions to 

accommodate a refiner’s inability to comply with the proposed 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 would be available to all refiners, small and nonsmall, though relief would be granted on a case-by-case basis following a showing of 

certain requirements; primarily that compliance through the use of credits was not 

feasible. We are proposing that any hardship waiver would not be a total waiver of 

compliance; rather, a hardship waiver would be short-term relief that would allow a 

refiner facing a hardship situation to, for example, receive additional time to comply. 

This hardship provision would allow a refiner to seek a delay in the case that there was 

insufficient time to comply. 

Finally, we believe that in reality, less leadtime than shown in Table V-3 would 

actually be necessary. We held discussions with many refiners during 2011, and so they

have been well aware of Tier 3 and are familiar with the likely requirements. During our 

subsequent discussions with technology vendors and engineering firms, they explained to 

us that many refiners have already initiated, and by now, likely completed their scoping 

studies. Thus, actual time needed for designing, installing and starting of new 

desulfurization equipment for Tier 3 times would even be less than what we projected 

because many refineries may have already completed required scoping studies in 

anticipation of the Tier-3 standards. Moreover, lead times for those refineries that have 

yet to start the scoping process can also be expected to decrease, since fewer refineries 

will be competing for the services of the desulfurization vendors. We request comment 

on the amount of lead time that we are providing refiners to scope, design, permit, 

construct and startup a grassroots desulfurization unit, considering all the proposed 

flexibilities which allow refiners to stagger their capital investments and ease compliance.

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 proposed sulfur standards are: (1) 

refiners’ ability to procure design and construction services and (2) refiners’ ability to 
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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 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.363 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-4.

Table V-4 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-5. In 

 

363 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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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 

Table V-5 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 proposed Tier 3 sulfur standards, refiners are expected to invest $2.2 

billion between 2014 and 2019 and utilize approximately 1,000 front-end design and 

engineering jobs and 6,000 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 proposed sulfur standards. For an 

in depth assessment of stationary source implications, refer to Section V.B. For more on 

our E&C assessment, refer to Section 4.5 of the draft RIA. 

3. Per-Gallon Sulfur Caps

In much of Europe and Japan, the gasoline sulfur level is capped at 10 ppm. We, 

however, are not considering a 10-ppm cap for the U.S. The U.S. gasoline distribution 

system poses contamination challenges that make it difficult to set and enforce such a 

tight downstream per-gallon sulfur standard. In Europe, Japan, and California, finished 

petroleum products are generally shipped short distances directly from the refinery to the 

terminal with limited susceptibility to contamination. The U.S. has the longest and most 

complex gasoline distribution system in the world, making it harder to control sulfur 

contamination than in other countries. Petroleum products are shipped long distances 

through multi-product pipelines. Further, gasoline goes through the same pipelines and 

terminals back-to-back with jet fuel (containing up to 3,000 ppm sulfur). Products are 

often in the custody of a number of separate companies before reaching the terminal. 

This system is very effective at delivering petroleum products to the bulk of the country, 

but pipeline transport inevitably introduces the potential for sulfur contamination of the 

gasoline being shipped through pipelines. Additionally, gasoline additives needed to 

provide critical fuel performance characteristics (e.g., corrosion control, demulsifiers) 

also contain varying levels of sulfur which contribute to the overall sulfur content of 

gasoline. Therefore, we are proposing a 10-ppm refinery average sulfur standard 

(discussed in Section V.A.2) with higher per gallon caps at both the refinery gate and at 

all points downstream, which is similar to what currently exists 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 
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sulfur concentration that vehicles must be designed to tolerate. Since there are many 

opportunities for sulfur to be introduced into gasoline downstream of the refinery, these 

caps also limit downstream sulfur contamination and enable the enforcement of the 

gasoline sulfur standard in-use.

We are proposing two options for the per-gallon sulfur caps. Under the first 

option, we are proposing to maintain both the current 80-ppm refinery gate sulfur cap and 

95-ppm downstream sulfur cap.364 Because this represents no change from current 

requirements, we believe there would be no additional costs to refiners and downstream 

parties associated with satisfying these caps on gasoline sulfur content beyond those that 

were already incurred under the Tier 2 program. Compliance for downstream parties 

could be even easier given that the average refinery gate level would be lower. However, 

the high level of the caps means that vehicles still have to be designed to operate on high 

sulfur fuel, and there will be less attention paid to limiting contamination downstream of 

the refinery gate. 

Under the second approach, we are proposing that the refinery gate cap would be 

reduced to 50 ppm and the downstream cap would be reduced to 65 ppm, in other words, 

a 30-ppm reduction in the caps to go along with a 20-ppm drop in the average standard. 

We are proposing that the 50-ppm refinery gate cap would take effect on January 1, 2020 

when the small refiner, small volume refinery, and early credit use provisions would 

expire. The reason for the delay in the more stringent cap until 2020 is to avoid forcing 

additional refinery investments during the early credit usage period. A more stringent 

per-gallon cap would also be very difficult to enforce prior to the small refiner and small 

volume refinery provisions taking effect. Until that time, the current 80-ppm refinery

gate sulfur cap would apply. Additional time beyond when the 50-ppm refinery gate 

sulfur cap is implemented would be allowed for gasoline produced to an 80-ppm sulfur 

cap to clear the distribution system before the 65-ppm downstream sulfur cap would 

replace the current 95-ppm downstream sulfur cap. Beginning February 1, 2020, a 65-

ppm downstream sulfur cap would apply at all locations downstream of the refinery and 

importer gate with the exception of retail and wholesale-purchaser-consumer facilities. 

Beginning March 1, 2020, a 65-ppm downstream sulfur cap would apply at all locations 

in the gasoline distribution system downstream of the refinery and importer gate. We 

note that the additional time for parties to comply with a more stringent downstream 

sulfur cap mirrors the schedule for compliance under the Tier 2 program.

As discussed previously in Sections III and IV of today’s preamble, the vehicle 

emissions benefits associated with today’s proposal are driven by the proposed reduction 

in the average sulfur content of gasoline from 30 to 10 ppm. However, vehicle 

manufacturers have expressed concerns about the potential impacts on emissions 

performance if individual vehicles are exposed to gasoline above the proposed 10-ppm 

refinery average.365 As discussed in Section V.A.2.b, our analysis of the potential 

 

364 This approach is reflected in the draft regulatory text.

365 Alliance of Automobile Manufacturers (2011, October 6). Letter to EPA Administrator, Lisa Jackson.
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response to the proposed ABT provisions assessed three options for refineries: remaining 

at their current sulfur levels and using credits, reducing sulfur levels to 10 ppm and 

neither generating or using credits, or reducing sulfur levels to 5 ppm and generating 

credits. We did not have available information that would enable us to assess refineries 

that might stay above 10 ppm and reduce their sulfur levels part way (e.g., reduce sulfur 

from 50 ppm today to 20 ppm under Tier 3). Nevertheless, we anticipate that in most 

cases refineries would respond by making operational changes and/or minor investments 

in order to reduce their credit burden and reduce 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, means that we anticipate most 

credit-using refineries would still average less than 20 ppm in their physical gasoline 

production, and either all or virtually all gasoline would be expected to average at or 

below 30 ppm. Therefore, we believe that a 50-ppm per-gallon cap at the refinery gate 

would not impose any additional cost or burden beyond the current 80-ppm per-gallon 

cap. Our discussions with refiners indicate that a 50-ppm sulfur cap would provide 

refiners with sufficient flexibility to produce gasoline during temporary upsets and 

turnarounds through the use of credits without necessitating the installation of additional 

desulfurization equipment.366 However, it would provide some additional assurance of 

in-use gasoline quality and help to address vehicle manufacturer concerns. 

We also believe that implementing a 65-ppm downstream sulfur cap would 

provide essentially the same flexibilities to downstream parties as the existing sulfur 

caps. We believe that maintaining a 15-ppm differential between the proposed refinery

gate sulfur cap of 50 ppm and the proposed 65-ppm downstream sulfur cap would 

provide pipeline operators, transmix processors, and gasoline additive users the same 

flexibility as provided under the current 80/95 ppm sulfur caps. 

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.367 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. We believe that a 65-ppm sulfur cap would 

provide sufficient flexibility to allow pipeline operators to continue this practice. 

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 

 

366 Refer to Section 4.2.4.1 of the draft RIA for a more detailed discussion of the impacts of lowering the 

refinery gate sulfur cap.

367 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. 
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gasoline and jet fuel components in the transmix.368 Transmix processors do not handle 

sufficient volumes to support the installation of currently available desulfurization 

units.369 Data provided by the largest operator of transmix processing facilities indicates 

that relatively few batches of the gasoline they currently produce approach 80 ppm sulfur. 

Most batches are approximately 10 ppm above the current 30-ppm refinery sulfur 

average. Therefore, we believe that under a 10-ppm refinery average standard and 50-

ppm refinery sulfur cap, transmix processors would be able to produce gasoline 

sufficiently under the proposed 65-ppm downstream sulfur cap to accommodate the 

additional sulfur contribution from the use of additives and contamination during further 

distribution. Since the 65-ppm downstream cap would not take effect until 2020, while 

the 10-ppm average standard would take effect in 2017, we would have three years of 

experience with which to verify this and take corrective action if necessary. 

In addition to proposing refinery gate and downstream per gallon sulfur caps of 

either 80 ppm and 95 ppm or 50 ppm and 65 ppm, we are also requesting comment on the 

potential implementation of a refinery gate sulfur cap as low as 20 ppm and a 

downstream sulfur cap as low as 25 ppm. This would further constrain downstream 

contamination and limit the temporary exposure of vehicles in-use to sulfur levels that 

would significantly degrade their emission performance. This would serve to provide 

added assurance that all parts of the country would receive the full emission benefits of 

gasoline sulfur control. However, we are only seeking comment on it and not proposing 

it due to the potential cost increases resulting from further constraints on refinery and 

distribution system operations. While a 50-ppm refinery gate cap may not impact 

refinery costs, in order to meet a 20-ppm refinery gate cap and downstream standard of 

25 ppm we expect that essentially all refineries would need to invest to meet the 10-ppm 

annual average standard. Our modeling of a non-ABT scenario, discussed in Section 

VII.B, shows that the sulfur control costs would increase by almost 10 percent, with no 

net change in average in-use sulfur levels. Similarly, while a 65-ppm downstream cap 

may have little or no impact on downstream operations, a 25-ppm downstream sulfur cap 

would likely require changes in pipeline operations, treatment of gasoline transmix, and 

formulation and use of sulfur containing gasoline additives (e.g., corrosion inhibitors, and 

demulsifiers) that could further increase the costs of the standard. The extent of such 

impacts and associated costs, however, are difficult to quantify. Consequently we seek 

comment on the appropriateness, impacts, and costs of lowering the per-gallon caps to 20 

ppm at the refinery gate, and 25 ppm downstream.

Further, in order to facilitate the enforcement of the downstream cap and prevent 

the potential dumping of high sulfur materials into gasoline under the guise of adding 

gasoline additives, we are proposing additional requirements to clarify the treatment of 

 

368 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.

369 Transmix processors produce ~0.1 percent of the gasoline consumed in the U.S.
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gasoline additives. Parties that introduce additives to gasoline at over 1.0 volume percent 

are required to satisfy all of the obligations of a fuel manufacturer including 

demonstration that the finished blend meets the applicable sulfur specification. A party 

other than a fuel refiner or importer who adds a quantity of additive(s) amounting to less 

than 1.0 percent by volume of the resultant additive(s)/fuel mixture is not considered a 

fuel manufacturer.370 Thus, the addition of sulfur to finished gasoline from additives 

used at less than 1.0 volume percent is simply limited by the current 95-ppm downstream 

sulfur cap. We are proposing to limit the sulfur contribution from the use of a gasoline 

additive added downstream of the refinery at less than 1.0 volume percent to 3 ppm when 

added at the maximum recommended treatment rate. We believe that this limitation 

would not constrain the use of gasoline additives or result in significant additional costs 

to gasoline additive manufacturers. This is because information received from additive 

producers indicates 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. The maximum treatment rate is already stated on product transfer document or 

packaging for the additive. We are proposing a requirement that additive manufacturers 

maintain records of their additive production quality control activities, which demonstrate 

that the sulfur content of additive production batches complies with the proposed sulfur 

requirement, for five years and to make these available to EPA upon request. 

B. Refinery Air Permitting Interactions

It is important to the success of the proposed Tier 3 fuel program that refineries 

are able to obtain air permits, if needed, in time to complete the modifications necessary

to comply with the proposed gasoline sulfur program. Accordingly, we have considered 

the implications of permitting requirements with respect to the implementation of the 

proposed gasoline sulfur program. This section provides information on this topic. In 

summary, we believe that only a small percentage of refineries would likely need to make 

modifications that will trigger a requirement to apply for air permits, and we anticipate 

that these permit applications would be processed quickly enough that air permitting will 

not be a significant obstacle to timely compliance with the gasoline sulfur program. In 

contrast to the Tier 2 program, where EPA expected the need for NAAQS-related New 

Source Review (NSR) permits might be widespread among refineries, we believe that 

under the proposed Tier 3 gasoline sulfur standard at most only about 19 refineries would 

need NSR or Prevention of Significant Deterioration (PSD) permits. This number –

which equates to approximately 17 percent of the 111 refineries projected to be affected 

by the proposed Tier 3 standards - could be even lower if refineries apply emission 

controls to reduce emissions increases below the significance level or if they “net out” of 

NSR.

If our final assessment of permitting prospects following analysis of comments 

indicates it would be appropriate, we would form a special team to monitor for permitting 

delays and assist in resolving associated problems. We also anticipate that other new 

 

370 40 CFR 79.2(d)(1)
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requirements applicable to refineries that are being proposed for implementation in 

approximately the same period as the gasoline sulfur program would not interfere with 

the modifications needed to meet the new sulfur limits and would not create a 

competition for air permitting agency resources. 

We invite public comment on air permitting issues, and on possible actions we 

might be able to take to help make sure refineries can obtain needed permits 

expeditiously. As described in further detail in Sections V.B.4 and V.B.6, a number of 

mechanisms and resources are already available to help mitigate and streamline NSR 

permitting requirements associated with the proposed Tier 3 fuel program. For example, 

EPA has issued guidance on Best Available Control Technology (BACT) analysis for 

GHG emissions, including a white paper that identifies specific technologies available for 

refinery process units. As explained in greater detail below, we expect that the types of 

equipment and process technologies that refiners would select to meet the proposed Tier 

3 standards would generally be consistent with BACT for GHG emissions in terms of 

achievable, cost-effective, and energy-efficient design even absent the requirement to 

obtain a permit, meaning that such a requirement would not necessitate a shift in project 

design or increase costs.

1. Background on New Source Review Programs

The New Source Review (NSR) program, as it applies to existing major sources 

of air pollution, requires that a permit be issued before a source begins construction of 

any project to modify the source that would result in a significant emissions increase and 

a significant net emissions increase of a pollutant regulated under this program.371 The 

physical modifications and operational changes that we expect refineries would make to 

comply with the proposed gasoline sulfur standards (described in Section V.A.1.d) could 

result in emissions increases in one or more pollutants that may trigger NSR requirements 

for preconstruction air permits. NSR permits specify what emission limits must be met

by the new and modified equipment that is part of the proposed project. They may

contain conditions to make sure that the modifications being made match parameters in 

 

371 Generally, a source is a major source if its “potential to emit” a regulated NSR pollutant is greater than 

either 100 or 250 tons/year depending on the industrial type of the source and whether the area is 

designated nonattainment for the particular pollutant. All refineries in the U.S. are major sources for 

purposes of NSR. A major modification is a physical change or a change in the method of operation that 

causes a significant emissions increase and a significant net emissions increase of any pollutant regulated 

under the NSR program. (A net emissions increase differs from an emissions increase in that a net increase 

takes into account contemporaneous emissions changes from other projects at the source.) Significant 

emission rates vary depending on the pollutant and range from 0.6 to 100 tons/year for criteria (NAAQS) 

pollutants and their precursors. See 40 CFR 52.21(b)(23). For GHGs, modifications of existing sources 

trigger NSR permitting requirements when there is an increase of GHG emissions of at least 75,000 

tons/year of CO2 equivalent, as well as any increase of GHG emissions on a mass basis. At the time 

refineries are required to comply with the proposed fuel sulfur program, the GHG threshold may be 

different, but will not be lower than 50,000 tons/year. 
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the application that the permit-issuing agency relied on in its analysis. Permits contain 

emission limitations for new and modified units and also typically specify some aspects 

of how, consistent with the permit application, the project elements must be constructed 

and operated. For example, the permit may identify important design and operational 

parameters that are consistent with the established control technology determination(s) 

and help assure compliance with associated emission limitations. To assure that sources 

follow the permit requirements, permits also contain monitoring, recordkeeping, and 

reporting requirements. NSR permits are issued by a state or local air pollution control 

agency if it has its own permit program that has been approved by EPA in the State 

Implementation Plan (SIP) or if it has been delegated the authority to issue federal 

Prevention of Significant Deterioration (PSD) permits on behalf of EPA. An EPA 

Regional Office issues the permit in other cases.

There are two separate sets of major source permit requirements that may apply to 

modifications at a refinery depending on the attainment status of the area in which a 

refinery is located. Each set of requirements is applied on a pollutant-specific basis, so 

that in some cases both permit programs may apply to the same modification project. The 

PSD permit program applies to any major modification at a source located in a designated 

attainment or unclassifiable area for any NAAQS pollutant.372 PSD requires compliance 

with emission limitations achievable through installation of BACT, an air quality analysis

to show that the modification will not cause or contribute to a violation of any NAAQS or 

applicable PSD increment,373 an assessment of impact on visibility and other conditions 

in national parks and similar federal lands, an additional impacts analysis, and an 

opportunity for public involvement. The second set of requirements is known as the 

Nonattainment NSR program because it applies to major modifications at sources located 

in areas designated as nonattainment for a specific NAAQS pollutant.374 The 

Nonattainment NSR requirements include, among other things, that a proposed major 

modification meet the lowest achievable emission rate (LAER) for each triggering 

nonattainment pollutant for which the source is major and for which there will be a 

significant emissions increase, obtain emission offsets for those nonattainment pollutants, 

and provide an opportunity for public involvement. LAER is generally a more stringent 

emission limitation than BACT. LAER is derived from either the most stringent 

emission limitation contained in the implementation plan of any state for the same type of 

source or the most stringent emission limitation achieved in practice. Emission offsets 

 

372 The PSD program stems from part C of Title I of the Clean Air Act. The implementing regulations are 

contained in 40 CFR 51.166 and 52.21.

373 A system of “increments” is the mechanism used in the PSD program to define significant deterioration 

of ambient air quality for a pollutant. An increment is the maximum allowable increase in ambient 

concentrations of a pollutant in an area relative to a specified baseline. Increases above that level are 

considered to significantly deteriorate air quality and cannot be allowed.

374 The Nonattainment NSR program stems from part D of Title I of the Clean Air Act. The implementing 

regulations are contained in 40 CFR 51.165 and 50 CFR part 51 appendix S. Under Nonattainment NSR, a 

major source is generally any source with a potential to emit of 100 tons/year or more of the nonattainment 

pollutant, regardless of industrial type (lower thresholds apply for some pollutants/classifications). The 

thresholds for a significant emissions increase under Nonattainment NSR are generally the same as under 

PSD but lower for certain pollutants/classifications.
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are emissions reductions, generally obtained from other existing stationary sources 

located in the vicinity of a proposed source. Such offsets must be equal to or larger than 

the emissions increase resulting from the modification to ensure that the growth being 

allowed to occur does not interfere with the ability of an area to continue making 

reasonable further progress towards attainment of the NAAQS.

As described previously in Section V.A.1.d, there are several types of process 

changes refineries could make to meet the proposed gasoline sulfur levels. To different 

degrees, all these technologies involve process heat from fuel combustion and, thus, have 

the potential to increase emissions of pollutants associated with combustion that are 

regulated under NSR375, such as NOX, VOCs, PM2.5, PM10, CO, SO2, and GHGs. The 

addition of certain technologies could also result in equipment leaks of petroleum 

compounds, which could increase emissions of VOCs and other pollutants. It is also 

possible that the removal of more sulfur from the gasoline stream could require increased 

capacity or increased utilization of other refinery processes, such as hydrogen plants and 

sulfur recovery units (SRUs), which are sources of air emissions. The emissions 

increases associated with a desulfurization project would vary from refinery to refinery, 

depending on a number of refinery-specific factors, such as the refinery output volume, 

refinery configuration, feedstocks, choice of desulfurization technology, and type of fuel 

used to operate affected process heaters. 

As described in more detail in Section V.B.4, we anticipate that the types of 

changes 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. The major NSR permitting requirements would not be triggered for several 

reasons: because the emissions increase or the net emissions increase is naturally less 

than the significant level, because the refinery installs control technologies on projectaffected units to further limit the emissions increase, and/or because the refinery “nets 

out” all or part of the emissions increase. 

However, we anticipate that some refineries have the potential to experience 

significant emissions increases and significant net emissions increases as a result of 

process changes necessary to meet the proposed gasoline sulfur standard and, therefore, 

may trigger major NSR (Nonattainment NSR and/or PSD). These facilities 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 do not anticipate that the time frames required for the small number of 

affected refineries to obtain any needed NSR and/or PSD permits will present an obstacle 

to timely compliance with the proposed Tier 3 gasoline sulfur requirements. We are 

proposing approximately 3 years of lead time. However, as discussed in section V.E., 

 

375 Toxic air pollutants are excluded from the PSD program. 42 U.S.C. 7412(b)(6); 40 CFR 

52.21(b)(50)(v).
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this is extended to up to 6 years of lead time for all small refineries, as well as for all 

other refineries if they take advantage of the flexibility of the early credit provisions. In 

comparison, as discussed in section V.A.2.c, 95 of the 111 refineries are anticipated to be 

able to comply within 2 years, and the remaining 16 within 3 years. For the 16 that may

require up to 3 years to comply due to the construction of grassroots hydrotreaters, only 2 

of these are projected to potentially trigger the need for new permits, and even then only

for PSD for greenhouse gases, and only if they choose to produce their own hydrogen. 

As a result, only two refineries may actually require the full 3 years to comply.

For facilities subject to major NSR, the timing of permit issuance could vary

depending on a number of factors, including the clarity and completeness of the 

application, the complexity of process changes, the type of permit required, air quality

impact, control technology reviews, and the permitting agency’s overall permit workload. 

The time spent preparing a permit application is under the control of the applicant. Once 

a permit application is complete, permitting authorities operating under approved SIPs

should be able to issue a permit within 9 to 12 months if the permit applies to NAAQS 

pollutants. Because EPA-issued permits and permits issued by states operating under a 

delegation from EPA are subject to additional analysis and interagency consultation steps 

specified in federal law, it can take a few more months if, for example, there are 

endangered species or historical preservation issues.376 For permits that apply only to 

GHGs, we anticipate that less time will be necessary both to prepare the application and 

for the permitting authority to approve the permit. The CAA requires that EPA take final 

action on a PSD permit within one year of the filing with the agency of a complete 

application. 42 U.S.C. 7475(c). Refineries that are able to avoid major NSR may be 

required to obtain a state-issued minor NSR permit. Generally, minor NSR permits 

involve less extensive and/or stringent requirements and have shorter processing times 

than major NSR permits.

2. Background on NSR Experience Under the Tier 2 Fuel Program

Many of the modifications that refineries are projected to make in order to comply

with the proposed Tier 3 fuel program are similar in type, although not necessarily in 

number or magnitude, to the changes that were needed to comply with the Tier 2 fuel 

program finalized in 2000. Therefore, information on the Tier 2 experience may assist 

the public in understanding the permitting issues for the Tier 3 fuel program and in 

providing comment on possible actions we might undertake to help refineries 

expeditiously obtain needed permits.

 

376 These processing time periods assume that the refinery can successfully show that the emission 

increases associated with the modifications will not cause or contribute to a violation of any NAAQS or 

increment (under PSD) or can obtain needed emissions offsets for the emission increases (under 

Nonattainment NSR). 
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The Tier 2 program was designed to reduce the average sulfur content of gasoline 

from about 300 ppm to 30 ppm, a reduction of about 90 percent. Anticipating that many 

refineries would have to make modifications that might trigger the need for NSR permits, 

we addressed the permitting issue in the proposal for the Tier 2 program, in the final rule, 

and during implementation. At proposal, we provided background information on the 

NSR program and its relationship to the types of changes likely to be required at 

refineries. We had not estimated the number of refineries that might trigger NSR, but we 

stated that the number could be substantial. We invited comment on a number of actions 

that EPA, states, and/or refineries could pursue in order to help refineries avoid the need 

for NSR permits or to obtain permits more expeditiously than might otherwise be the 

case. These actions included the following:

 Use of plantwide applicability limits, possibly facilitated by new EPA 

guidance or rules addressing issues specific to refineries.

 Issuance of new federal guidance on streamlining certain major NSR 

permitting requirements such as control technology and compliance 

parameters.

 Use of emissions reductions resulting from vehicles operating on lower sulfur 

gasoline as offsets for refineries seeking Nonattainment NSR permits.

 Use of model permits and permit applications.

 EPA refinery permitting teams.

The Tier 2 proposal also addressed issues related to the Title V permitting 

program377, and requested comments on possible approaches by which refineries might 

satisfy some NSR and Title V requirements at the same time.

We received comments on refinery permitting issues from the refining industry, 

the automobile manufacturing industry, state and local agencies that administer air 

permitting programs, and environmental and community groups. Based on these 

comments and statutory constraints, we decided that it was not necessary or appropriate 

to exempt Tier 2 projects from the normally applicable preconstruction review process. 

We also decided not to pursue the development of guidance on plantwide applicability

limits for refineries based on comments suggesting this would be an unproductive effort

 

377 Title V of the 1990 CAA Amendments requires all major sources and some minor sources of air 

pollution to obtain an operating permit. A Title V permit contains all air pollution requirements that apply 

to the source, including emissions limits and monitoring, record keeping, and reporting requirements. It 

also requires that the source report its compliance status to the permitting authority annually. All existing 

refineries potentially affected by the proposed Tier 3 fuel standards have Title V permits and, because Title 

V permits by themselves generally do not establish new applicable requirements, the only implication of 

the proposed Tier 3 fuel standards would be the “roll-in” of any new NSR permit requirements into existing 

refinery Title V permits. Permitting agencies have efficient processes to accomplish this that do not delay 

construction of proposed projects.
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because of the complexity of refineries. Nonetheless, we concluded that it was useful to 

add certainty to the anticipated permitting actions and schedules, and to minimize the 

possibility of delay. Accordingly, EPA took two types of actions to promote these 

objectives. First, as we are now proposing for Tier 3 (see proposed program flexibilities 

discussion in V.E.1.-3.), we structured the Tier 2 gasoline sulfur program to allow 

additional lead time for many refineries (i.e., certain refineries would be able to make 

desulfurization changes later than the otherwise applicable compliance date to meet Tier 

2 requirements). This approach was expected to help address the concerns over the 

availability of necessary new equipment and permitting backlogs caused by many 

refineries acting to obtain permits and order equipment within the same time 

period.Second, we stated our intention to take several actions during implementation of 

the Tier 2 rule to expedite and impart greater certainty in obtaining necessary major NSR 

permits (described in more detail below). We also stated our intention to assist states and 

refiners on a case-by-case basis in their efforts to address any unique permitting problems 

that might arise and, thus, remedy potential problems that could cause unanticipated 

delays. We committed to work with refiners and the state/local permitting agencies on a 

case-by-case basis, where a refinery had unique circumstances that necessitated unique 

treatment. We clarified that, in our efforts to provide greater certainty and to facilitate 

more expeditious permitting, we were in no way shortcutting existing opportunities for 

public participation in making permitting decisions. We encouraged refineries to begin 

discussions with permitting authorities and to submit permit applications as early as 

possible. 

The final Tier 2 rule identified three key actions that we intended to take (and 

subsequently took) to provide assistance that would be useful toward helping states issue 

timely permits to refineries. The first such action was to organize a special EPA team, 

comprised of Headquarters and Regional Office experts, to track the overall progress in 

permit issuance and to be available to assist state and local permitting authorities, 

refineries, and the public upon request to resolve site-specific permitting issues. The 

team made special efforts to be aware of state and local permitting actions that were 

underway during the time between the finalization of the Tier 2 program and the 

compliance time frame. Experience during this period suggested that state and local 

permitting agencies, as predicted in their comments on the proposed Tier 2 program, 

were able to process permit applications in a timely manner, without much need for 

special troubleshooting help from the EPA team. In many cases, the modifications to 

allow compliance with Tier 2 requirements were subject to only minor NSR permitting 

requirements rather than major NSR, or those modifications were rolled into another 

permitting action that was needed for other modifications or expansions due to other 

technical or market developments. We believe it is reasonable to expect that similar 

outcomes (refineries not needing major NSR permits) would result in connection with air 

permitting for the modifications refineries would need to make under the proposed Tier 3 

gasoline sulfur program.

The second action we took was to develop new guidance on emission control 

technology requirements to meet BACT and LAER. We issued this guidance in 2001. It 

addressed the levels of control that could be reasonably anticipated to represent BACT or 

LAER under the major NSR requirements. Our general experience following the release 
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of this BACT/LAER guidance was that it did not play a substantial role in the permitting 

of refinery projects for Tier 2. That is, due to their own expertise and the need to 

consider refinery-specific factors, state and local permitting authorities generally did not 

find it necessary to rely on our guidance in their own permitting processes for refineries 

making changes to meet the Tier 2 requirements. In addition, many of the refinery

projects were able to avoid major NSR, so BACT and LAER were not requirements that 

had to be met. Again, we believe it is reasonable to expect that similar outcomes 

(refineries not needing major NSR permits) would result in connection with air 

permitting for the modifications refineries would need to make to meet the proposed 

gasoline sulfur standard.

The third action we took was a fast-track effort to develop new guidance on the 

use of emissions reductions resulting from vehicles operating on lower sulfur gasoline as 

emission offsets for refineries seeking Nonattainment NSR permits. We invited comment 

on a draft version of this guidance five months after the final Tier 2 rule. The draft 

guidance discussed in depth how the use of such offsets could be made consistent with 

seven criteria given in the CAA for such offsets. We received many comments from state 

and local air agencies and community groups opposing the proposed offset guidance on 

legal, fairness, and environmental justice grounds. One refiner recommended that EPA 

set aside a portion of the Tier 2 reductions in each state as offsets, rather than leaving this 

decision to each state. We did not finalize the draft guidance, and no state further 

pursued a system under which vehicle emissions reductions were made available to 

refineries as offsets for Nonattainment NSR permits.

3. Changes in the NSR Permitting Program since Tier 2 Final Rule

The Tier 2 fuel program was promulgated in early 2000, and most refiners were 

required to comply with those requirements by 2006. During and since that period, there 

have been a number of changes to the major NSR programs. These changes are 

summarized here to facilitate public comment as to how these changes may affect 

whether refinery modifications undertaken as a result of the proposed Tier 3 fuel program 

would trigger NSR and/or the requirements that refiners and permitting authorities would

have to meet. 

In 2002, we issued a final rule known as the NSR Reform Rule.378 This rule 

revised the EPA-administered NSR programs and changed the minimum approvals 

required for SIP-approved NSR programs for NSR applicability. Some of the provisions 

of the 2002 final rule have been vacated by the Court, subsequently amended by EPA, or 

are currently under reconsideration. Two key components of the NSR Reform Rule that 

remain in place are a new applicability test for projects involving existing emissions units 

(the “actual-to-projected-actual” applicability test) and provisions that allow for the 

establishment of plantwide applicability limits (PALs). The change in the applicability

test since the Tier 2 experience means that fewer modifications may be found to have 

 

378 67 FR 80186 (December 31, 2002).
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emissions increases that are above the significant emission levels, in which case fewer 

major NSR permits may need to be issued. The PAL provisions offer a voluntary

alternative for determining major NSR applicability that can provide sources with 

significant flexibility to manage facility-wide air emissions without triggering major NSR 

permitting. Refineries that have established PALs or will establish one or more PALs 

prior to or as part of permitting associated with the Tier 3 fuel program will be far less 

likely to trigger major NSR permitting requirements.

We have also taken a series of actions that have had the effect of making 

emissions of GHGs a factor in determining whether a PSD permit is required for a 

refinery modification. Under the applicable PSD provisions in the CAA, GHGs became 

regulated under the PSD program on January 2, 2011 after EPA adopted tailpipe 

emissions standards for these pollutants under Title II of the CAA. Because the 

incorporation of GHGs into the PSD program had the potential to significantly expand 

the number of sources required to obtain PSD permits, EPA adopted the 2010 Tailoring 

Rule to phase in the PSD permitting requirements according to a series of steps based on 

different GHG emission thresholds.379 At this time the Tailoring Rule requires that any

modification at an existing refinery that increases GHG emissions by 75,000 tons per 

year or more of CO2 equivalent and also produces any mass increase in GHG emissions 

would trigger the need for a PSD permit that addresses GHG emissions.380 Because 

there are no NAAQS for GHGs and, therefore no nonattainment areas, only PSD could 

potentially apply to a refinery modification with respect to increases in GHG emissions. 

The analysis (described in Section V.B.4) indicates that only a small number of large 

refineries would be affected. For the sources that would need a PSD permit for GHGs, 

the main substantive requirement for obtaining the permit is to apply BACT for GHG 

emissions from the new or modified unit(s) because an air quality analysis is not 

required.

Another development since 2000 has been the establishment of several new and 

revised NAAQS and the designation of nonattainment areas under some of these 

NAAQS. At the time of the final Tier 2 rule, the NAAQS of most relevance to 

Nonattainment NSR permitting for refineries were the 1-hour ozone NAAQS, the PM10

NAAQS, and the SO2 NAAQS, because these NAAQS accounted for the vast majority of 

the existing nonattainment areas. The designation of new nonattainment areas under the 

1997 NAAQS for 8-hour ozone became effective in 2004. Designations under the 1997 

NAAQS for PM2.5 became effective in 2005. In 2008, we again revised the ozone 

NAAQS and designations under that standard became effective in July 2012.381 In 2006, 

we revised the 24-hour PM2.5 NAAQS and in 2009 (2011 for a few areas) we designated 

areas under the 2006 PM2.5 standard.382 In December 2012 we revised the primary

annual PM2.5 NAAQS and designations associated with that revised standard are 

 

379 75 FR 31514 (June 3, 2010).

380 77 FR 41051 (July 12, 2012).

381 77 FR 30088 (May 21, 2012)

382 Listings of areas currently designated nonattainment for all the NAAQS are available at 

http://www.epa.gov/oar/oaqps/greenbk/index.html.
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expected to become effective in 2015.383 One effect of this evolution of the NAAQS and 

associated attainment status for areas is that it has become more common over time for 

sources to be located in ozone or PM2.5 nonattainment areas and thus subject to 

Nonattainment NSR rather than to PSD for their VOC, NOX, and PM2.5 emissions 

increases. However, over the same time period, some areas currently designated as 

nonattainment for ozone and/or PM2.5 are expected to be redesignated to attainment. 

Therefore, we do not expect a dramatic shift on a national basis in one direction or the 

other. 

In 2008, we issued a final rule specifying in detail how NSR applies to PM2.5.

384

 

In addition, in 2010 we supplemented this rule with additional provisions for the PSD 

program specifically.

385

 The latest rule, among other things, established PM2.5

increments, and as of October 20, 2011, sources that trigger PSD for PM2.5 are required to 

show compliance with the applicable increment, in addition to showing that they do not 

cause or contribute to a violation of any of the PM2.5 NAAQS. 

In 2010, EPA finalized new NAAQS for 1-hour NO2 and 1-hour SO2.

386

 EPA has 

completed the initial round of mandatory designations for the 1-hour NO2 NAAQS and 

all areas have been designated unclassifiable/attainment.387 The first round of 

designations for the 1-hour SO2 NAAQS will be made in June 2013, thus we do expect 

there to be nonattainment areas for the 1-hour SO2 NAAQS by the time that refineries 

might need to seek NSR permits to make the required facility modifications for the Tier 3 

program. However, we expect that no refinery would have increases in SO2 emissions 

that are large enough to trigger major NSR, so any change in attainment status for the 

SO2 NAAQS should have no effect on permitting issues. 

In areas designated attainment or unclassifiable for the 1-hour NO2 or 1-hour SO2

NAAQS, the air quality impacts assessment required to obtain a PSD permit can present 

new challenges for permit applicants. This is because demonstrating that a modification 

will not cause or contribute to a violation of these 1-hour standards may require more 

refined and data-intensive air quality modeling approaches than has previously been 

required to make this demonstration with respect to the pre-existing NAAQS for NO2 and 

 

383 78 FR 3086 (January 15, 2013). 

384 73 FR 28321 (May 18, 2008). On January 4, 2013,the U.S. Court of Appeals for the District of 

Columbia, in Natural Resources Defense Council v. EPA, No. 08-1250, 2013 WL 45653 (filed July 15, 

2008, consolidated with 09-1102, 11-1430), issued a judgment that remanded EPA’s 2008 PM 2.5 NSR 

rule and ordered the EPA to repromulgate the rule “pursuant to Subpart 4 consistent with this opinion.” Id. 

at *8. Subpart 4 of Part D, Title 1 of the CAA establishes additional provisions for particulate matter 

nonattainment areas. EPA is evaluating the impact of the court decision on the provisions of the 2008 rule.

385 75 FR 64864 (October 20, 2010). On January 22, 2013, the U.S. Court of Appeals for the District of 

Columbia, in Sierra Club v. EPA, No. 10-1413 (filed Dec. 17. 2010), issued a judgment that vacated and 

remanded the provisions at 40 C.F.R.51.166(k)(2) and 52.21(k)(2) (concerning implementation of the 

PM2.5 SILs) and vacated the provisions at 40 C.F.R. 51.166(i)(5)(i)(c) and 52.21(i)(5)(i)(c) (adding the 

PM2.5 SMC) that were promulgated as part of the rule.

386 75 FR 6474 (February 9, 2010) and 75 FR 35520 (June 22, 2010).

387 77 FR 9532 (February 17, 2012).
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SO2. To assist permit applicants in performing the required analysis of 1-hour NO2 and 

SO2 air quality impacts, we have issued several guidance memos that describe available 

alternative approaches and flexibilities.388 In addition, EPA provides technical assistance 

with modeling issues upon request.

 

4. Assessment of Tier 3 Refinery Changes and Permitting Implications

EPA has performed a 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 proposed Tier 3 fuel specifications. We have 

also assessed the likely effects of those changes on refinery emissions. This assessment 

is described in more detail in Section 5.4 of the draft RIA. Using this assessment, we 

were able to gain a reasonable understanding of the potential scope of NSR permitting 

requirements refiners might face under the proposed 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. The assessment and this conclusion take into account the changes in the 

NSR program and its context since 2000 described in Section V.B.3. A technical 

memorandum describing in detail our analysis and results is in the public docket for this 

proposal.390 

In our analysis, we started with the estimates we have made regarding the 

physical and operational changes that would be required at each refinery (described in 

Section 5.4 of the draft 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 post-treatment unit for sulfur reduction. Based on the projected refineryspecific changes, we estimated the increased demand for energy (i.e., fuel to generate 

process heat, steam and electricity), hydrogen, and sulfur recovery associated with 

meeting the proposed Tier 3 standards. We selected representative industry emission 

factors for NAAQS 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. 

To determine upper and lower bounds for emissions increases resulting from 

changes necessary to meet the proposed Tier 3 gasoline sulfur specification, we evaluated 

two scenarios, a no ABT scenario (assuming no trading of sulfur credits) and the primary

ABT scenario described in Section 5.4 of the draft RIA. We did not have sufficient 

detailed information to predict which refineries would find it most profitable to generate 

 

388 These memos are available at http://www.epa.gov/ttn/scram/guidance_clarificationmemos.htm, 

http://www.epa.gov/region07/air/nsr/nsrmemos/appwso2.pdf, and 

http://www.epa.gov/nsr/documents/20100629no2guidance.pdf. 

390 Keller, P. (2013, February). New Source Review Permitting Impact Analysis for Proposed Tier 3 

Gasoline Program. Memorandum to the docket.
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additional electrical power, hydrogen and high octane blendstocks internally 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, hydrogen, and high octane blendstocks 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 scenarios and 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. We found that the no 

ABT scenario, low case had the lowest number of refineries estimated to trigger major 

NSR and the primary ABT scenario, high case had the highest, although the overall 

numbers did not vary greatly.

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 primary ABT scenario, high case are presented here. The results for the no 

ABT scenario, which are not greatly different, are described in the previously referenced 

technical memo found in the docket for this rulemaking. 

. We found that under the primary ABT scenario, high case, 19 refineries 

appeared likely to have significant emissions increases for one or more pollutants and 

thus would trigger major NSR.391 This equates to approximately 17 percent of the 111 

refineries projected to be affected by the proposed Tier 3 standards. Of these 19

refineries, we predicted that 13 refineries would need permits for NAAQS-related 

pollutants and their precursors (PSD and/or Nonattainment NSR) and for GHGs (results 

for GHG are discussed below). Thus, compared to the Tier 2 program where EPA 

 

391 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.
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expected the need for NAAQS-related NSR permits might be widespread among 

refineries, we believe that under the proposed Tier 3 program only about 13 refineries 

would 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 13 refineries just described as potentially needing NSR permits for NAAQS 

pollutants are also projected to need PSD permits for GHGs. In addition to these 13

refineries, we estimated that 6 other refineries may require a PSD permit addressing only 

GHG emissions from new or modified equipment that is part of the project. For these 

refineries, BACT must 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 would modify or add to meet the proposed Tier 3 standards would generally 

be consistent with BACT for GHG emissions in terms of achievable, cost-effective, and 

energy-efficient design even absent the requirement to obtain a permit, meaning that such 

a requirement would not necessitate any shift in project design or increase 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, most of the new or modified units expected to be involved in 

refinery projects designed to meet the proposed 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. EPA requests comment on the assumption that the cost of any equipment or 

process technology that refiners would choose for NSR compliance is built into the 

refineries’ estimated cost for compliance with Tier 3. 

In 2010, EPA issued a white paper on available and emerging technologies for 

reducing GHGs from the petroleum refining industry.

392

 This white paper addresses the 

types of equipment expected to be involved in projects designed to meet the proposed 

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 

 

392 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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affected units as BACT, 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 would also be required. Significantly, no air 

quality modeling of GHGs would 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.

We invite public comment on our analysis including ways in which we might 

improve the assessment between now and the final rule.

5. New Source Performance Standards and National Emission Standards for 

Hazardous Air Pollutants for Refineries

In addition to the proposed Tier 3 rulemaking, we are also conducting other 

rulemakings to set new and revised limits for direct emissions from refineries of 

NAAQS-related pollutants and hazardous air pollutants (HAPs). This section provides 

summary information on these rulemaking efforts, so that comments on the proposed Tier 

3 program can be more fully informed. 

We first regulated petroleum refineries in 1974 when the agency issued the New 

Source Performance Standards (NSPS) to control NAAQS-related air pollutants. The 

NSPS applies to refinery process units that commenced construction, reconstruction, or 

modification after June 11, 1973, but before May 14, 2007. On June 24, 2008, we 

amended the NSPS and issued new standards for most process units constructed, 

reconstructed, or modified after May 14, 2007 and for flares which commence 

construction, modification, or reconstruction after June 24, 2008. We were petitioned to 

reconsider these final rules and on September 12, 2012, EPA finalized amendments and 

technical corrections to address issues related to flares and process heaters. There are two 

existing Maximum Achievable Control Technology (MACT) standards to control HAPs 

that apply specifically to petroleum refineries.393 These standards are referred to as 

MACT 1 and 2 and were issued in 1995 and 2002, respectively. EPA is required to 

perform risk and technology reviews (RTR) to assess residual risk for MACT standards 

for HAPs within eight years of the promulgation of the original MACT standards. In 

addition, EPA is required to perform a technology review of advancement in processes, 

practices and control requirements every eight years after promulgation of the MACT. 

 

393 These are codified in 40 CFR 63, Subpart CC (National Emission Standards for Hazardous Air 

Pollutants From Petroleum refineries) and 40 CFR 63, Subpart UUU (National Emission Standards for 

Hazardous Air Pollutants for Petroleum Refineries: Catalytic Cracking Units, Catalytic Reforming Units, 

and Sulfur Recovery Units).
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EPA is planning to issue a single rulemaking that will address the RTR analyses for both 

MACT 1 and 2. 

Finally, on March 21, 2011 EPA published MACT standards for Industrial, 

Commercial, and Institutional Boilers and Process Heaters and on January 31, 2013 EPA 

finalized revisions to those standards based on reconsideration.394 These standards apply 

to boilers and process heaters at refineries. Because any changes that are made to meet 

new requirements of these rulemakings would likely reduce rather than increase refinery

emissions, we do not expect these modifications to trigger NSR unless a refinery chooses 

to increase the capacity of one or more of its units at the same time.395 This means that 

we expect the final rules would not themselves increase the major NSR workload for 

refinery environmental permitting staffs or for permitting agencies in the same period that 

these organizations need to prepare and process permit applications related to the 

proposed Tier 3 fuel program. (Minor NSR permitting workload may be affected.) 

6. Steps for Streamlining the Permitting Process

As we did for Tier 2, we could organize a Headquarters-Regional response team 

to monitor and address any delays in permitting by facilitating coordination among 

organizations where needed to resolve permitting issues. The mission of this team would 

also include tracking the overall progress in permit issuance and assisting state and local 

permitting authorities, refineries, and the public upon request to resolve site-specific 

permitting issues. The team would be comprised of EPA staff knowledgeable about 

permitting programs and refinery operations, so the team could provide expert assistance 

and troubleshoot permitting issues in a timely fashion. We invite comment from 

refineries, permitting authorities, and others regarding the usefulness of such a team.

We will continue to maintain and refine the tools and resources that have proven 

useful to permit applicants and permitting authorities, such as the RACT/BACT/LAER 

clearinghouse, the Support Center for Regulatory Atmospheric Modeling, and our webbased resources on GHG permitting. These GHG permitting resources include various 

materials on the topic of BACT for GHG, including white papers and copies of our 

comments on recent draft permits proposed by state and local permitting agencies.396 

One of the white papers, described previously in Section V.B.4, addresses petroleum 

refining, and provides information on control techniques and measures that are available 

to mitigate GHG emissions in order to assist states and local air pollution control 

agencies, tribal authorities, and regulated entities in implementing technologies or 

 

394 76 FR 15451 (March 21, 2011) and 78 FR 7138 (January 31, 2013).

395 Some approaches for controlling NAAQS-related pollutants do require additional electrical power or 

otherwise may increase GHG emissions. Conversely, some approaches to increasing energy efficiency 

(and thereby reducing GHG emissions) can increase emissions of NAAQS-related pollutants if 

compensating changes are not made in downstream emission control devices, for example increases in NOx 

emissions from higher combustion temperatures.

396 See “PSD and Title V Permitting Guidance for Greenhouse Gases,” March 2011 and “Available and 

Emerging Technologies for Reducing Greenhouse Gas Emissions from the Petroleum Refining Industry,” 

October 2010, both available at http://www.epa.gov/nsr/ghgpermitting.html.
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measures to reduce GHGs under the CAA, particularly in permitting under the PSD 

program and the assessment of BACT. 

 We believe the guidance we provided on BACT and LAER for NOX and VOC 

shortly after the final Tier 2 rule was not widely utilized by either refineries or permitting 

authorities. Nevertheless, we invite comment on whether additional guidance on BACT 

and LAER for these and other NAAQS-related pollutants would be useful to support 

permitting for Tier 3-related modifications as well as the appropriate scope and substance 

of such guidance. We anticipate that if we do develop any new BACT/LAER guidance, 

we would provide an opportunity for public comment on the draft guidance before 

finalizing it.

For Tier 3-related NSR permit applications submitted to EPA Regional Offices, 

we will assist members of the local communities in understanding the applications and 

our proposed permits, in offering comment, and participating in our decisions. We also 

encourage similar assistance efforts by the state and local permitting authorities, and we 

invite comment on the specific forms that our and their support should take.

EPA received comments during the Tier 2 rulemaking that vehicle emissions 

reductions should be allowed to be used as part of “netting out” of NSR. This concept is 

now relevant to GHG emissions, in addition to the NAAQS-related pollutants to which it 

was relevant at the time of the Tier 2 rulemaking. At that time we responded to the 

comments by saying that the use of vehicle emissions reductions for netting purposes was 

not permitted by the NSR regulations, since the creditable emissions reductions used for 

netting purposes must result from reductions occurring at the modified source. We noted, 

for example, that the definition of net emissions increase in 40 CFR 52.21(b)(3)(i) 

includes only increases and decreases occurring “at the source”. We believe this 

provision in the NSR rules is well founded in the CAA. Setting aside the issue of 

whether we have authority to change this provision, the potential consequences of 

changing it to allow the use of non-source emissions reductions in “netting out” of NSR 

would be far reaching. We are not proposing such a change as part of this rulemaking, 

and we believe that any proposal for such a change should be based on a much better 

assessment of its possible implications than can be accomplished as part of this 

rulemaking. We also note that “netting out” of NSR could be a complex and often timeconsuming process because all contemporaneous emissions increases and decreases 

within the refinery must be properly accounted for, so the ability to use vehicle emissions 

reductions in the netting analysis would not automatically make “netting out” a timesaving shortcut around the permitting process that would otherwise apply. Nevertheless, 

we invite comment regarding how critical such a change may be to successful permitting 

of the modifications needed to comply with the proposed Tier 3 program, possible legal 

rationales for such a change, and the possible implications beyond the Tier 3 rule 

including ways to limit such implications by making the change specific to vehicle 

emissions reductions that are closely linked to changes in fuel properties that result from 

the refinery modifications.

Finally, we invite comment on issues related to state and local minor source NSR 

programs and how they may relate to implementation of the proposed Tier 3 fuel 
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program. EPA rules give states wide latitude in the design and operation of their minor 

source programs, and we do not routinely require states to report their minor source 

permitting activity to us. Therefore, focused comments on this issue would be helpful. 

C. Standards for Denatured Fuel Ethanol and Other Oxygenates

Current gasoline requirements include the prohibition on blending gasoline with 

denatured fuel ethanol (DFE) that has sulfur content higher than 30 ppm.397 This 

requirement reflects the current 30-ppm refinery average sulfur requirement. Consistent 

with this requirement and our proposed introduction of a 10-ppm refinery average sulfur 

standard, we propose that manufacturers of DFE for use by oxygenate blenders would be 

required to meet a 10-ppm sulfur cap.

California’s requirements for DFE, which became effective in December 2003, 

are as follows: maximum 10 ppm sulfur, maximum 0.06 volume percent benzene, 

maximum 0.5 volume percent olefins, and maximum 1.7 volume percent aromatics.398 

Denaturants used to manufacture DFE must also meet maximum benzene, olefins, and 

aromatics specifications that are based on the anticipated dilution ratio when blended 

with ethanol.399 Additionally, in July 2002, the Renewable Fuel Association (RFA) 

recommended that all ethanol produced for use in the U.S. should be manufactured in 

accordance with the California specifications primarily because of logistical difficulties 

in segregating ethanol destined for California from other destinations.400 RFA recently

indicated that all ethanol producers are adhering to this recommendation. Some DFE 

marketers have also adopted California’s DFE requirements as part of their 

specifications.401 Consequently, we believe that the implementation of a 10-ppm sulfur 

cap for DFE would not result in increased burden to ethanol producers. We are 

proposing it to reduce emissions from motor vehicles, the same reason we are proposing 

a more stringent sulfur standard for gasoline into which it is blended.

Further, the ASTM International specification for DFE allows only natural 

gasoline, gasoline blendstocks, and gasoline as denaturants.402 Similar to the ASTM 

specifications, we are proposing to require that only natural gasoline, gasoline, and 

gasoline blendstocks for oxygenate blending (BOB) be used as ethanol denaturants. We 

 

397 40 CFR 80.385(e).

398 California Code of Regulations, Title 13, Section 2262.9, “Requirements Regarding Denatured Ethanol 

Intended For Use as a Blend Component in California Gasoline”. 

399 The current California requirements which are based on a maximum 5 percent denaturant level in DFE 

are as follows: maximum 1.1 volume percent benzene, maximum 10 volume percent olefins, and maximum 

35 volume percent aromatics. ASTM International Standard D4806-11(a), “Standard Specification for 

Denatured Fuel Ethanol for Blending with Gasolines for Use as Automotive Spark-Ignition Engine Fuel” 

requires that the maximum denaturant concentration in DFE is 5 volume percent. 

400 RFA publication entitled “Fuel Ethanol, Industry Guidelines, Specifications and Procedures,” 2011.

401 For example, Aventine Renewable Energy Fuel-Grade Ethanol specifications at 

http://www.aventinerei.com/pdfs/fuel_grade_spec.pdf

402 ASTM International D4806-11(a), “Standard Specification for Denatured Ethanol for Blending with 

Gasolines for Use as Automotive Spark-Ignition Engine Fuel”. 
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believe that this limitation is needed to prevent the use of other denaturants that might 

adversely impact vehicle emissions performance. We believe that the ASTM 

specifications are already in use by industry and, therefore, EPA’s adoption of the same 

specifications would not result in an increased burden to DFE producers. We further 

believe that limiting the type of gasoline blendstocks that can be used as denaturant to 

BOBs would not impose a new burden on DFE producers since other gasoline 

blendstocks would not typically be available to DFE producers. We request comment on 

whether there should be an allowance for other gasoline blendstocks to be used as ethanol 

denaturants.

With regard to benzene, olefins, and aromatics, we believe that these proposed 

requirements along with Internal Revenue Service ethanol denaturant requirements would 

limit benzene, olefins, and aromatics content of DFE to very low levels. Therefore, we 

are not proposing any limits on these parameters in DFE. Nevertheless, we are 

requesting comments on whether we should adopt the State of California’s benzene, 

olefin, and aromatics specifications for DFE. We are also proposing to limit the 

maximum concentration of denaturant that can be used in DFE to 2 volume percent. 

Under the RFS2 regulations, if the denaturant level is 2 volume percent or less 

(effectively less than 2.5 volume percent considering rounding) the entire volume of 

denatured fuel ethanol can be used for determining compliance with the RFS2 renewable 

fuel volume requirements.

403

We also request comment on whether to require manufacturers of denaturants for 

use in DFE to register with EPA, and demonstrate compliance with the maximum sulfur, 

benzene, olefins, and aromatics specifications enforced in the State of California based on 

the anticipated dilution with ethanol. We believe that such additional requirements on the 

denaturants used to manufacture DFE would not be necessary given that DFE producers 

would be required to meet the proposed specifications and the proposed requirement that 

denaturant concentration in DFE be limited to a maximum of 2 volume percent.

We propose that producers of DFE would be required to meet the proposed fuel 

quality requirements for their product and provide batch reports to EPA. This is similar 

to the requirements for gasoline refiners. This approach would provide an appropriate 

level of assurance on the quality of DFE which has become such a large component in the 

gasoline fuel pool. We believe that this approach would not result in additional burden to 

ethanol producers beyond the annual batch reports that they would need to submit to EPA 

and the information they provide on product transfer documents (PTDs). Currently, 

under the fuel and fuel additives registration requirements at 40 CFR part 79, 

manufacturers of DFE are required to register their products with EPA prior to 

introducing DFE into commerce. Also, DFE producers currently test each batch of their 

product in order to provide assurance to blenders that it meets the current fuel quality

requirements. This information is critical to ethanol blenders to avoid testing each batch 

 

403 See the definition of Renewable Fuel in 40 CFR 80.1401.
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of an ethanol blend that they manufacture. The proposed requirements would facilitate 

unfettered downstream ethanol blending. 

We are also proposing that the proposed fuel quality specifications and 

requirements for DFE (except those related to the use of denaturants) would apply to 

other oxygenates used in gasoline. We are proposing that the oxygenate quality

requirements would become effective for oxygenate producers/importers on January 1, 

2017. We are proposing that oxygenate producers and importers would be required to 

register by December 1, 2016, or 30 days prior to the date when they produce/import 

oxygenate (which ever date is later). Registration under the RFS program would be 

sufficient to fulfill this proposed requirement. We are proposing that oxygenate blenders 

be required to begin using oxygenates that comply with the proposed requirements 

beginning March 1, 2017. We also seek comment on the ability of these blenders to 

comply with the proposed requirements earlier, and appropriateness of such an earlier 

compliance date. 

D. Standards for Fuel Used in Flexible Fueled Vehicles

FFVs are vehicles that are capable of operating on both gasoline and gasoline 

blends containing up to 85 volume percent denatured ethanol. Whether FFVs are 

operating on clear gasoline (E0), E85, or any level of ethanol in between, to maintain 

emission performance the vehicles still need the fuel to meet certain quality

specifications, such as the 10-ppm average gasoline sulfur standard proposed today. We 

anticipate that the volume of higher level ethanol blends used in FFVs may increase 

substantially as the volume requirements of the RFS program increase. 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.404 Therefore 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 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)405 (i.e., contain 

only carbon, hydrogen, oxygen, nitrogen, and sulfur) apply to any fuel used in an FFV. 

At the same time, it is not necessarily clear how we should implement such standards 

within the context of our existing regulations. For this reason we are seeking comment 

on appropriate regulatory mechanisms for doing so. The following sections discuss 

potential approaches for gasoline-ethanol blends both above and below 50 percent 

 

404 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. 

405 73 FR 22277, 22281 (April 25, 2008).
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ethanol. We have also developed a possible approach, along with draft regulations, that 

are included in the docket on which we specifically seek comment.406 

1. Standards for E51-83

Historically, “E85” has been used to describe fuel blends containing gasoline and 

ethanol with a minimum and maximum ethanol content of 68 volume percent and 83 

volume percent, respectively. The recent update to the ASTM International specification 

for “E85” included a reduction in the minimum ethanol concentration to 51 volume 

percent.407 As part of the updated specification, ASTM retired the name “E85” in favor 

of “ethanol fuel blends for flexible-fuel automotive spark-ignition engines.” ASTM took 

this action because the term “E85” has caused confusion regarding the variability in the 

ethanol content depending upon seasonal climactic conditions and regional gasoline 

volatility specifications. For the purposes of this discussion, “E51-83” refers to the fuel 

which meets the new ASTM D5798-11 specifications.

Currently, only reformulated gasoline blendstocks for oxygenate blending 

(RBOBs) and gasoline that has previously been demonstrated to comply with applicable 

EPA specifications (reformulated gasoline (RFG) and conventional gasoline (CG)) are 

used to manufacture E51-83.408 The Agency believes that the use of these blendstocks 

prevents inappropriate blending components (e.g., chemical wastes) from being used in 

the production of E51-83. Use of these blendstocks would also help ensure that E51-83 

meets the necessary sulfur levels we are proposing today. We note, however, that use of 

only these blendstocks is interfering with expansion of E51-83 into the marketplace by 

preventing blends at the upper range of the allowed ethanol content. At higher ethanol 

concentrations, blenders often cannot meet the minimum volatility specifications set by

ASTM for cold start performance when using only BOBs and gasoline. Prior to the 

recent update of the ASTM specifications, it was frequently not possible to manufacture 

“E85” that met both the ASTM minimum volatility specification and the EPA 

requirements regarding the blendstocks that can be used. As a result, some marketers 

discontinued distributing “E85.” Although the ASTM update provided a compliance 

method for manufacturing E51-83, the result is that less ethanol can be used in FFVs, 

because the ethanol concentration is forced down from 83 percent toward the 51 percent 

minimum.

To address this situation, we believe that we need to prescribe requirements for 

E51-83 that would enable the continued expansion into the marketplace. We believe that 

such requirements could focus more on the product and less on how it is made. We also 

believe that E51-83 should meet the same sulfur, RVP, and benzene standards otherwise 

 

406 Herzog, J. (January 2012). Possible Approach to Fuel Quality Standards for Fuel Used in Flexible-Fuel 

Automotive Spark-Ignition Vehicles (FFVs), Memorandum to the docket 

407 ASTM International D5798-11, “Standard Specification for Flexible-Fuel Automotive Spark-Ignition 

Engines”.

408 Letter to Robert Sydney, Division of Energy Resources, Boston, MA, from James Caldwell, U.S. EPA, 

February 15, 2006. 
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applicable to gasoline as well as the “substantially similar” requirements. We are 

therefore seeking comments on whether we could extend these requirements to E51-83. 

We note that establishing such requirements could allow the use of butane and natural 

gasoline liquids (NGL) to manufacture E51-83 with sufficient volatility to meet the 

ASTM specifications. Butane is commonly blended into gasoline and NGL is the 

denaturant specified by ASTM for the manufacture of DFE.409 Additionally, because 

NGL and butane are less expensive than gasoline or BOBs, we anticipate that such a 

change could help to reduce the price of E51-83 relative to finished gasoline.410

Further, we note that requiring E51-83 to meet the same standards as gasoline 

would subject E51-83 manufacturers to all the sampling, testing, and reporting 

obligations of refiners. While this would provide maximum blending flexibility, it could 

also limit the parties that might choose to blend E51-83. Currently oxygenate blenders 

are exempt from much of this regulatory burden. For this reason, we are also seeking 

comments on whether we could establish requirements that would allow producers of 

E51-83 to avoid the compliance burdens of a refiner. We are seeking comments on one 

such approach that would require the use of only blendstocks that meet certain 

specifications to produce E51-83. We believe that use of only blendstocks (including 

butane and NGL) that meet these specifications would ensure the final blend would 

always meet the standards. These approaches are discussed in greater detail in the docket 

for this rulemaking.411 We seek comment on these approaches, and any other approaches 

that could be used to remove hurdles for blending of E51-83 while still ensuring the 

product meets the fuel quality requirements needed to maintain vehicle emission 

performance.

2. Standards for Mid-Level Ethanol Blends (E16-50)

As discussed earlier, whether FFVs are operating on clear gasoline (E0), E85, or 

any level of ethanol in between, to maintain emission performance these vehicles still 

need the fuel to meet certain quality specifications. For this reason, we believe it is 

important that higher ethanol blends also meet the same standards that apply to gasoline. 

Our various standards for gasoline already 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.412 As a result, our gasoline standards already apply 

to E16-50 ethanol blends. And yet, such fuels currently can only be used in FFVs. 

Therefore, in addition to seeking comment on the need to have E16-50 blends comply

with the gasoline sulfur, benzene, and RVP standards, we also seek comment on the 

 

409 ASTM International D4806-11(a), “Standard Specification for Denatured Ethanol for Blending with 

Gasolines for Use as Automotive Spark-Ignition Engine Fuel”.

410 In August of 2011 the retail price of E85 was approximately 60 cents per gallon more than gasoline on 

an energy content adjusted basis.

411 Possible Approach to Fuel Quality Standards for Fuel Used in Flexible-Fuel Automotive Spark-Ignition 

Vehicles (FFVs). 

412 40 CFR 79.56(e)(1)(i).
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means of doing so. For example, can and should the Agency simply treat E16-50 as 

gasoline under our regulations and clarify that gasoline means any fuel that contains 50 

percent or more gasoline? Alternatively, should the Agency treat E16-50 as an 

alternative fuel used in FFVs? In which case we seek comment on whether we should 

take the same approach for E16-50 as discussed above for E51-83 with respect to sulfur, 

benzene, RVP standards, and substantially similar requirements under section 211(f). 

In the context of considering whether and how to apply gasoline standards and 

requirements to E16-50 we also seek comment on whether it might be an appropriate 

reading of our regulatory and statutory authority to allow E16 to E50 blends to have 

higher RVP levels than otherwise required by our regulations for gasoline. As the 

ethanol level increases, the volatility increase caused by blending ethanol with gasoline 

begins to decline, such that at E30 there is only about a 0.5-psi RVP increase. While still 

an increase compared to the standards that apply to gasoline other than E9-10, it is 

considerably less than the full 1-psi RVP increase that results at E10. The evaporative 

emission increase caused by E30 would then be less than for E10. Thus, we seek 

comment on whether it would be an appropriate reading of our regulatory and statutory

authority to allow higher RVP levels for such blends, at least in some limited situations 

and time frames (e.g., using existing regulatory research exemptions for demonstration 

programs) where new efforts are being made to introduce such blends into the market. 

We further seek comment on data that might help quantify both the evaporative and 

exhaust emission impacts necessary to support any such action.

E. Proposed Program Flexibilities 

1. Averaging, Banking, and Trading Program 

As mentioned in Section V.A.2.b, we are proposing an ABT program which 

reduces the cost and promotes the feasibility of the program by allowing refiners and 

importers to choose the most economical compliance strategy (investment in technology, 

credits, or both) to meet the proposed Tier 3 average gasoline sulfur standard. The 

program allows refiners and importers to generate standard credits for overcompliance 

with the 10-ppm sulfur standard beginning in 2017. These credits could be generated 

indefinitely and banked or transferred to others for compliance with the average sulfur 

standard. The proposed program also permits refiners and importers to generate early 

credits for overcompliance with today’s 30-ppm average sulfur standard from 2014 to 

2016. Early credits may be used towards compliance with the 10-ppm standard 

beginning in 2017, banked for use through 2019, and/or transferred to other refiners or 

importers subject to the sulfur standard. 

a. Eligibility

Under the ABT program, we are proposing that U.S. refiners who produce 

gasoline by processing crude oil and/or intermediate feedstocks through refinery

processing units are eligible to generate both early credits (2014-2016) and standard 

credits (2017 and later). As proposed, importers are also eligible to generate both early 

and standard sulfur credits on gasoline imported into the United States. 
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We are proposing that sulfur credits may only be generated for gasoline that is 

subject to the proposed sulfur requirements as described at §80.1603. This excludes 

gasoline designated for export. It also excludes California gasoline (gasoline produced or 

imported for use in California) but includes gasoline produced by California refineries for 

use outside the state. Although California gasoline is not covered by our proposed sulfur 

program, we seek comment on whether to include California gasoline in the ongoing 

ABT program under Tier 3 (not the early credit program). The result would be a national 

10-ppm average gasoline sulfur standard. This approach could provide some additional 

compliance flexibility to refiners, but it would also require reporting of batch data to EPA 

for California gasoline.

We have received inquiries whether fuel ethanol producers or blenders should be 

eligible to generate credits under the proposed gasoline sulfur program. Denatured fuel 

ethanol currently contains around 9 ppm sulfur on average, ranging anywhere from 2 to 

almost 30 ppm.413 While certain batches of ethanol could theoretically be low enough in 

sulfur to generate credits, it is our desire to limit credit generation to companies required 

to comply with the proposed Tier 3 sulfur standards, i.e., refiners and importers. 

Experience in the unleaded gasoline program suggests widespread abuse and fraud when

credits have been allowed to be generated or sold by non-obligated parties. Thus, in 

order to allow ethanol producers (or blenders) to generate sulfur credits under Tier 3, they

would need to be treated as refiners and subject to our batch testing, reporting, and 

recordkeeping requirements for the finished gasoline they produce.414 Currently, 

downstream blenders are exempt from these regulations because the certification and 

compliance burden is being borne by the upstream refiners.415 Furthermore, since many

refiners currently comply with our standards taking into consideration the fuel property 

changes expected as a result of downstream ethanol blending, providing ethanol blenders 

with sulfur credit would result in double counting the effects of ethanol. To avoid this, 

we would need to restructure our gasoline regulations to shift the point of compliance to 

the many terminals and bulk plants where ethanol is blended and finished gasoline is 

produced instead of the refinery gate. While possible, this would significantly expand the 

amount of sampling, testing, recordkeeping, and reporting required to demonstrate 

compliance with our gasoline standards. It would also considerably expand the amount 

of sampling, testing, recordkeeping, and reporting required of ethanol blenders. As 

discussed in Section V.C, we are proposing a cap of 10 ppm on the sulfur content of 

denatured fuel ethanol (DFE). Over compliance with the per-gallon cap would not be a 

valid basis for credit generation, as you would expect that in all cases the DFE would be 

below the cap. To allow credit generation, we would need to propose an additional 

annual average sulfur standard for DFE at some level below 10 ppm, and allow credits to 

be generated for over compliance with that standard. Accordingly, we do not believe it is 

 

413 Report on Ethanol Producers Survey, Presented at the California Phase 3 Reformulated Gasoline 

Regulation Workshop, June 15, 2000, Carl Reeder, Archer Daniels Midland

414 40 CFR 80.330, 80.335, 80.365, and 80.370.

415 Under the proposed Tier 3 program, as explained in Section V.C, we are requiring fuel ethanol 

producers to comply with the 10-ppm standard. However, for the reasons discussed above, we still do not 

believe it is appropriate to allow them to generate sulfur credits under the proposed ABT program.
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appropriate to allow ethanol producers or blenders to generate sulfur credits under the 

proposed gasoline sulfur program.

b. Standard Credit Generation

Under the Tier 3 ABT program, we are proposing standard credit generation 

provisions similar to those offered under Tier 2 as well as the MSAT2 gasoline benzene 

program. We are proposing an ongoing sulfur credit program that would allow refiners 

and importers to average within and across companies to meet the new 10-ppm average

sulfur standard in the most cost-effective manner possible. Refiners and importers could 

generate standard credits for overcomplying with the 10-ppm standard on a volumeweighted annual average basis beginning January 1, 2017. Standard credit generation

periods would be 12 months long and synchronized with compliance demonstration 

periods.

We are proposing that small refiners and small volume refineries could generate 

standard credits beginning with the start of their program on January 1, 2020. Eligible 

small refining entities could also generate standard credits for over compliance with the 

10-ppm standard from January 1, 2017 through December 31, 2019 by voluntarily opting 

in to the Tier 3 sulfur program during a time period when it would otherwise not apply. 

Regardless of whether they were generated early or not, all standard credits generated by

small refiners and small volume refineries would be subject to the credit life provisions 

described in Section V.E.1.d. For a summary of the small refiner and small volume 

refinery ABT provisions, refer to Section V.E.1.f.

c. Early Credit Generation

To encourage early gasoline desulfurization and give the refining industry

flexibility to stagger their investments over time, we are proposing that refiners and 

importers could also generate early credits for overcomplying with today’s 30-ppm 

gasoline sulfur standard on a volume-weighted annual average basis from January 1, 

2014 through December 31, 2016. Under the ABT program, we are proposing that 

refiners and importers would not need to establish a gasoline sulfur baseline or meet a 

trigger point in order to generate early credits. They would simply need to demonstrate 

that their average U.S. gasoline sulfur levels are below today’s 30-ppm Tier 2 standard 

during the early credit generation period. We believe this simple early credit approach is 

possible because U.S. gasoline is currently averaging around 30 ppm today based on 

compliance data. Since during the proposed early credit generation period refiners and 

importers would need to continue to comply with the existing Tier 2 sulfur standards, 

absent Tier 3, they would need to maintain this level of performance on an industry

average basis. Accordingly, any additional gasoline sulfur reductions beyond 30 ppm 

could thus be attributed to the proposed Tier 3 program.

Refiners and importers supplying gasoline containing less than 30 ppm sulfur 

from January 1, 2014 through December 31, 2016 could choose from generating either 

standard credits under the existing Tier 2 program or early credits under the proposed 

Tier 3 program, but not both (at least not for the same volume of gasoline). Sulfur credits 
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would be generated on an annual average basis. Refiners and importers could make the 

decision at the end of the year whether credits generated in 2014, 2015 or 2016 would be 

more valuable used/traded to comply with the Tier 2 program or banked for the Tier 3 

program. Some year-end credits could be designated as Tier 2 and some designated as 

Tier 3 provided the same volume of gasoline was only used to generate one type of 

credit. We believe that the proposed early credit program structure is the simplest 

approach to giving refiners and importers incentive for doing more sulfur control earlier 

than required and providing additional lead time to meet the Tier 3 annual average 

standard. We seek comments on alternative ways to structure the early credit program to 

help ease the transition from Tier 2 to Tier 3.

Under past fuel programs (e.g., MSAT2), we precluded importers from generating 

early credits under the premise that they did not need additional lead time to comply with 

our fuel standards because, most likely, they would not be investing in new refining 

technologies. We also thought it would be difficult for them to establish representative 

baselines from which early credits could be generated. Since we are not proposing early 

credit baselines under Tier 3, as discussed above, we are proposing to allow importers to 

generate early credits for sending over-compliant gasoline to the United States prior to 

the start of the program, but seek comment on the appropriateness of doing so. 

d. Credit Life Provisions

Under the Tier 3 ABT program, we are proposing that early credits must be used 

towards compliance within three years from the start of the program; otherwise they 

would expire and become invalid. In other words, early credits must be applied towards 

the 2017, 2018 or 2019 compliance years. After February 29, 2020, all early credits 

would expire and become invalid. The proposed three-year early credit life provision 

would offer considerable flexibility to refiners phasing in Tier 3 gasoline sulfur controls 

while still placing a 2020 end date at which point the intended sulfur program is fully

implemented and enforceable. It would provide a date certain by when auto 

manufacturers could have confidence for the design of their vehicles that all vehicles inuse 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) could allow higher sulfur levels to continue well beyond 2019. Refiners that are 

able to generate early credits may choose to hold onto them for later use, rather than trade 

them to other refiners who may need them sooner. The proposed three-year early credit 

life provision would also be consistent with the duration of the small volume refinery

provisions described below. We seek comment on the lifetime of early credits and the 

implications on in-use sulfur levels beyond 2019 should we allow them to have a longer 

credit life.

We are proposing that standard credits must be used within five years from the 

year they were generated (regardless of when/if they are traded); otherwise they would 

expire and become invalid. For example, standard credits generated in 2017 could be 

applied towards 2018-2022 compliance, as well as 2017 compliance. After February 28, 

2023, standard credits generated in 2017 would expire and become invalid. Similarly, 

standard credits generated in 2018 could be applied towards 2019-2023 compliance, as 
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well as 2018 compliance. After February 29, 2024, standard credits generated in 2018 

would expire, and so on and so forth.

We believe the five-year standard credit life provision, when final, would give 

refiners and importers sufficient time to use credits generated in previous years while still 

placing limitations on credit life that would help with enforcement. Five years is 

consistent with the proposed recordkeeping and reporting requirements (described in 

more detail in Section V.F.1) as well as the current Tier 2 and MSAT2 standard credit life 

provisions.

e. Credit Trading Provisions

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. If this occurs, as in past fuel 

programs, we are proposing that both the seller and purchaser would 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.

Under the proposed Tier 3 ABT program, 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. An exception exists where a credit 

generator transfers credits to a refiner or importer who inadvertently cannot use all the 

credits. In this case, the credits could be transferred a second time to another refiner or 

importer. After the second trade, the credits must be used or they would be terminated. 

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. 

Nonetheless, we seek comment on the need for allowing more than two trades for sulfur 

credits under the proposed Tier 3 program.

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 the unleaded gasoline program 

and has since appeared in subsequent fuels rulemakings. Maintaining this prohibition 

would allow for maximum program enforceability and consistency with all of our other 

ABT programs for mobile sources and their fuels. Nonetheless, we seek comment on the 

need for this restriction under the proposed Tier 3 program.

f. Summary of ABT Provisions for Small Refiners and Small Volume Refineries

We are proposing that small refiners and small volume refineries would have an 

additional three years to comply with the 10-ppm annual average standard, or until 
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January 1, 2020. This is the primary form of relief offered to small refining entities under 

the proposed Tier 3 gasoline sulfur program. The proposed credit provisions are similar 

to those offered to non-small refiners. Eligible small refiners and small volume refineries 

would be able to generate early credits for overcomplying with the 30-ppm Tier 2 

standard from January 1, 2014 through December 31, 2016. Like non-small refiners, 

they would need to make the decision whether these credits would be more valuable 

under the Tier 2 program or the proposed Tier 3 program. While early credits could help 

postpone investments by up to three years, they could not be used by small refiners or 

small refineries to postpone sulfur investments beyond their January 1, 2020 start date. 

However, early credits generated by small entities from 2014-2016 could be traded/sold 

to non-small refiners subject to the January 1, 2017 standard and the credit revenues 

could be used to help offset their Tier 3 investments.

As explained above, small refiners and small volume refineries could generate 

standard credits relative to the 10-ppm standard beginning with the start of their program 

on January 1, 2020. Eligible small refining entities could also generate standard credits 

for over compliance with the 10-ppm standard from January 1, 2017 through December 

31, 2019 by voluntarily opting in to the Tier 3 sulfur program earlier than required. 

Regulatory flexibility provisions offered to small refiners and small volume refineries are 

described in more detail below.

2. Regulatory Flexibility Provisions

a. Small Business Regulatory Flexibility Provisions

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 proposed 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 feasible and necessary 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, we believe that 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 proposing 

several regulatory flexibility provisions for small entities in the fuels industry to reduce 

the burden that our proposed program could have on them.

Small entities generally lack the resources that are available to larger companies, 

including those large companies that own small-capacity refineries, 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. As such, we are 

proposing provisions that would provide assistance for small entities in meeting the 

proposed Tier 3 standards. This proposed approach would allow the overall program to 
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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 believe 

that small business regulatory flexibilities could 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.

i. Delayed Standards for Small Refiners

As explained in Sections V.A.1.c and V.E.1.f, we are proposing an option that 

would allow small refiners to postpone compliance with the Tier 3 program for up to 

three years. This delayed compliance schedule for small refiners is not intended as an 

opportunity for those refiners to greatly expand their production of >10 ppm sulfur 

gasoline, but rather would help small refiners with compliance with the program. Since 

the compliance costs for their competitors would rise during these three years and since 

their gasoline would be sold into the same fungible market, this delay would not only

provide them more lead time, but also financial support towards later compliance. Small 

refiners choosing this option would 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 sulfur standard would 

begin on January 1, 2020. Any small refiner choosing this option would be allowed to 

continue using Tier 2 gasoline sulfur credits through December 31, 2019 to meet their 

refinery average 30-ppm sulfur standard (however, these credits may not be used for 

compliance with the proposed Tier 3 10-ppm average 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 because, as they noted in their comments during the 

Panel process, transmix processors may not be able to reprocess finished gasoline down 

to this level. 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 in Section XI.C, we are proposing to either maintain the current 

80/95 ppm caps or to lower them to 50/65 ppm. Should we lower the caps to 50/65 ppm, 
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given the stringency of the 10-ppm average standard, we anticipate that they would 

provide the same level of flexibility for refiners, pipelines, terminals, transmix 

processors, and gasoline additive manufacturers as the current 80/95 ppm caps. Should 

we lower the caps to 50/65, we are proposing to allow the current Tier 2 80-ppm refinery

gate cap to remain in place through December 31, 2019. Compliance with the 50-ppm 

refinery gate cap would begin on January 1, 2020, when the 10-ppm average sulfur 

standard is required for all refiners. Similarly, we are proposing to allow the Tier 2 95-

ppm downstream cap to remain in effect through February 29, 2020. Compliance with 

the 65-ppm downstream cap would begin on March 1, 2020. For more information on 

the proposed cap provisions, refer to Section V.A.3.

iii.Credit-related Flexibilities

As described above in Section V.E.1, we are proposing an ABT program. 

Refiners and importers would be able to generate early sulfur credits from January 1, 

2014 through December 31, 2016 relative to the current 30-ppm Tier 2 average sulfur 

standard (i.e., credits may be generated for any reductions below 30 ppm prior to the start 

of the general Tier 3 program). Beginning January 1, 2017 standard credits may be 

generated for overcompliance with the proposed 10-ppm Tier 3 sulfur standard. In 

addition, small refiners and small volume refineries would be able to generate standard 

credits from January 1, 2017 through December 31, 2019 for reductions below 10 ppm 

prior to their proposed program start date of January 1, 2020.

During the SBREFA Panel process, one Small Entity Representative (SER) 

commented that importers should be allowed to participate in the credit program. In 

previous EPA fuel programs, importers have generally been treated as refiners, except for 

the purposes of early credit generation. Refiners have historically been required to 

establish a baseline in order to generate early credits. Importers generally do not have a 

specific baseline or amount of fuel that they import in a given year, so participation in the 

early credit market would not have been feasible under those programs. However, under 

the proposed Tier 3 sulfur program, refiners and importers are not required to establish 

baselines; the existing 30-ppm Tier 2 standard serves as the “baseline.” Therefore, as 

discussed above in Section V.E.1.c, we are proposing to allow importers to participate in 

the early credit program as well as the ongoing standard credit program.

iv. Gasoline Additive Manufacturers

During the SBREFA Panel process, some gasoline additive manufacturing SERs 

raised the concern that they would have difficulty meeting a 25-ppm per-gallon sulfur 

cap, and the Panel recommended that EPA request comment on whether or not gasoline 

additives should be allowed to remain at levels above 25 ppm sulfur, and on potential 

methods for ensuring that bulk additives do not increase the sulfur level of the resultant 

fuel blend. However, as discussed above and in Section V.A.3, we are proposing to 

either retain the current 80/95 ppm caps or only go to 50/65 ppm. Both of these options 

would have the same 15-ppm differential between the refinery gate and downstream caps, 

thus we are not proposing any additional provisions for gasoline additives beyond what 

already exists under the current Tier 2 program.
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b. Small Volume Refinery Provisions

During the development of this proposal and throughout the SBREFA process, it 

became evident that some refineries may experience higher compliance costs on a pergallon basis than other refineries, and in some cases considerably higher. It also became 

apparent that in many of these cases it was not necessarily a refinery owned by a 

refiner/company that would meet the SBA definition of a small business (however, these 

refineries tend to be small volume refineries). In an oversupplied gasoline market, these 

refineries may have difficulty justifying capital investments to comply with the proposed 

sulfur standard. In recognition of this concern under the RFS program, Congress granted 

all small refineries with a crude oil throughput of less than or equal to 75,000 barrels per 

calendar day (bpcd) additional time to comply. As such, we are also proposing 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 would allow them 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. We are 

proposing that approved small volume refineries would receive a three-year delay

(January 1, 2017 through December 31, 2019) in meeting the 10-ppm average gasoline 

sulfur standard, similar to the small refiner delay. Credit generation opportunities for 

approved small volume refineries would be identical to those proposed for small refiners 

as described in Section V.E.1.f. 

A refiner would need to apply and be approved for small volume refinery status. 

We are proposing a small volume refinery net crude throughput of less than or equal to 

75,000 bpcd, and we request comment on whether or not a different crude throughput 

would be more appropriate. To determine compliance with this threshold, we propose to 

base the crude throughput on the highest crude throughput for either the 2010 or 2011 

calendar years.

3. Provisions for Refiners Facing Hardship Situations

As in previous fuel programs, we are proposing hardship provisions to 

accommodate a refiner’s inability to comply with the proposed 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 would be available to all refiners, small and nonsmall, though relief would be granted on a case-by-case basis following a showing of 

certain requirements; primarily that compliance through the use of credits was not 

feasible. We are proposing that any hardship waiver would not be a total waiver of 

compliance; rather, a hardship waiver would be short-term relief that would allow a 

refiner facing a hardship situation to, for example, receive additional time to comply. 

EPA would determine appropriate hardship relief based on the nature and degree of the 

hardship, as presented by the refiner in their hardship application, and on our assessment 

of the credit market.
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In addition to the unforeseen circumstances and extreme hardship circumstances 

waivers being proposed today and discussed in more detail below, the Panel also 

recommended that EPA request comment on the concept of long-term cap relief should 

we lower the sulfur caps below the current 80/95-ppm level if the circumstances both 

warrant it and can be structured in a way to allow for it. Such a provision may require 

segregation of their fuel through to the retail station in order for it not to preclude 

enforcement on the gasoline supplied by other refiners serving the area. Therefore, in 

providing comment on such a hardship provision, please also comment on potential 

compliance and enforcement mechanisms to account for such longer-term relief, e.g., fuel 

segregation, tracking, reporting and recordkeeping, etc.

a. Temporary Waivers Based on Unforeseen Circumstances

We are proposing a provision which, at our discretion, would permit any refiner 

to seek a temporary waiver from the Tier 3 sulfur standards under certain rare 

circumstances. This waiver provision is similar to provisions in existing fuel regulations. 

It 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 could seek a hardship waiver for relief 

if it could demonstrate that the magnitude of the impact was so severe as to require such 

an extension. We are proposing that the refiner would be required to show that: (1) the 

waiver would be in the public interest; (2) the nonconformity was unavoidable; (3) it 

would meet the proposed Tier 3 standards as expeditiously as possible; (4) it would make 

up the air quality detriment associated with the nonconforming gasoline, where 

practicable; and (5) it would 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 previous fuels regulations, and are 

necessary and appropriate to ensure that any waivers granted would be limited in scope.

As discussed, such a request would 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 would also need to show that other avenues for mitigating 

the problem, such as the purchase of credits toward compliance under the proposed credit 

provisions, had been pursued and yet were insufficient or unavailable. In light of the 

proposed flexibilities including the ABT program, we expect that the need for such 

requests would 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 proposing a hardship provision where a refiner could 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 proposed rule would have to demonstrate that these 

criteria were met. In addition to showing that unusual circumstances exist that impose 

extreme hardship in meeting the proposed standards, the refiner would have to show that: 
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(1) it has made best efforts to comply, including through the purchase of credits; (2) the 

relief granted under this provision would be in the public interest; (3) the environmental 

impact would be acceptable; and (4) it has active plans to meet the requirements as 

expeditiously as possible. We expect that hardship relief requests under this provision 

would 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 was 

approved, we would expect to impose appropriate conditions to ensure that the refiner 

was 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 would 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 proposed overall 

program, we expect that the need for additional relief would be rare.

F. Compliance Provisions

For the most part, the proposed Tier 3 sulfur standards simply reflect a lowering 

of the current Tier 2 sulfur standards. Thus, we are proposing to retain most of the same 

compliance provisions as the current Tier 2 program, with exceptions as noted. However, 

we are also proposing and seeking comment on several fuel program regulatory

streamlining measures, including a broader program redesign to streamline the 

reformulated gasoline and anti-dumping regulations.416 Some of these streamlining 

measures, if adopted, may also impact the Tier 3 sulfur compliance provisions proposed 

below. 

1. Registration, Reporting, and Recordkeeping Requirements

Registration, recordkeeping, and reporting are necessary to track compliance with 

the Tier 3 standards and the ABT program. This section describes the proposed 

compliance provisions of today’s program.

a. Registration Requirements

We are proposing that 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 would be required to 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. After the program begins on January 1, 2017, any non-registered 

parties must register at least three months prior to producing gasoline or participating in 

the credit market under the Tier 3 program. Most refiners, importers, and ethanol 

producers are currently registered with EPA under other 40 CFR part 80 fuels programs. 

We are proposing that those who are already registered would not have to register again.

 

416 For more information on Part 80 regulatory streamlining options, refer to Section VI.
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For registration, we are proposing to use the same basic forms that previous fuels 

programs have used. These forms are well known in the regulated community and are 

simple to fill out. Upon receipt of a completed registration form, EPA would issue a 

unique 4-digit company identification number and a unique 5-digit facility identification 

number. As with existing fuels programs, these numbers would be required for all 

reports sent to EPA and for PTDs.

Registrations would not expire and would not have to be renewed; however, we 

are proposing that registered parties would be 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); and, for each facility

operated by the entity:

 Type of facility (e.g., refinery, import facility, pipeline, terminal, transmix 

facility, etc.)

 Facility name

 Physical location

 Contact name, telephone number, and e-mail address

b. Reporting Requirements

We are proposing to require refiners and importers to 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, we are also proposing to require refiners and importers to 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 would provide an effective means of 

monitoring compliance with the standards and the credit program. 

We are proposing that manufacturers 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: 

sulfur content, composition (i.e., composed only of carbon, hydrogen, nitrogen, oxygen, 

and sulfur), and denaturant concentration as applicable. 

We are proposing that reports would be due annually on March 31.

c. Recordkeeping Requirements

Similar to current EPA fuels programs, we are proposing that refiners and 

importers would be required to retain all records that demonstrate compliance with the 

Tier 3 program, including ABT program information. 
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We are proposing that manufacturers of DFE and other oxygenates would be 

required to keep records on individual batches of DFE/oxygenate (including batch 

volume, sulfur content, and denaturant concentration as applicable). 

All parties in the gasoline production and distribution system subject to today’s 

proposed rule would also be required to keep records of all PTDs and records of any

quality assurance programs. Records would need to be retained for five years. For credit 

transactions, records would need to be retained for five years from the usage date. 

Records would need to be made available to EPA on request. We are also proposing that 

if electronic records are kept, hard copies should be made available upon request.

We are proposing to allow parties to claim information submitted to EPA as 

confidential business information (CBI). Parties making such a claim would be required 

to follow all reporting guidance and clearly mark the information being claimed as 

proprietary. EPA would 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 proposing to retain that requirement under Tier 3. As with the 

Tier 2 program, this every batch testing requirement would be required to occur prior to 

the batch leaving the refinery. We are proposing to retain the current sampling, testing, 

and sample retention requirements. However, as discussed below in Section VI.A.3, we 

are proposing performance based measurement standards that would allow refiners to use 

alternate test methods for measuring sulfur.

We are proposing that manufacturers of DFE would be required to test each 

individual batch of DFE for its sulfur content. 

We request comment on these elements related to sampling and testing, as well as 

the sampling and testing requirements in the proposed regulations.

3. Small Refiner Compliance

To qualify for small refiner status under the Tier 3 program, we are proposing that 

a refiner must apply by July 1, 2013. As with our other EPA fuels programs, we are 

proposing to continue using the Small Business Administration definition of a small 

refiner—1,500 employees (company-wide). To qualify for small refiner status under Tier 

3, we are also proposing that a small refiner must meet the following additional criteria:

 The refiner must have produced gasoline from crude oil during the 2011 

calendar year.

 The refiner must have owned and operated the refinery during the period from 

January 1, 2011 through December 31, 2011. New owners that purchased a 
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refinery after that date would do so with full knowledge of the proposed 

regulations, and should have planned to comply along with their purchase 

decisions. As with existing fuel programs, we are proposing that 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 2011 could apply for small refiner status. In such cases, we 

would 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, we propose to limit this to a company

that owned the refinery at the time that it was shut down. New purchasers 

would 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, 2011 through 

December 31, 2011 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 2011 calendar year.

A refiner applying for status as a small refiner would be required to apply and 

provide EPA with several types of information, as specified in the regulations, by July 1, 

2013. All refiners seeking small refiner status under this program would need to apply

for small refiner status, regardless of whether or not the refiner had 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 proposed rule that are later 

found to contain false or inaccurate information would 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 would include the capacity of all 

refineries controlled by a refiner and by all subsidiaries and parent companies 

and joint ventures. We would presume that the information submitted to EIA 

is correct. (In cases where a company disagreed with this information, the 

company could petition EPA with appropriate data to correct the record when 

the company submitted its application for small refiner status. EPA could 

accept such alternate data at its discretion.)

 The name and address of each location where employees worked during the 

2011 calendar year; and the number of employees at each location during this 

time period. This would include the employees of the refiner and all 

subsidiaries and parent companies and joint ventures.
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 In the case of a refiner who reactivates a refinery that was either shutdown or 

non-operational from January 1, 2011 through December 31, 2011, the name 

and address of each 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.

 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 was true to the best of his/her knowledge and that the 

company owned the refinery as of January 1, 2011.

We are proposing that 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 proposing provisions which are similar to those in 

our existing fuels programs to allow an additional 30 months of lead time to comply with 

the Tier 3 program after the disqualifying event.417 The proposed 30 months of 

additional lead time would only apply to refineries that had previously been subject to 

small refiner relief, as we believe there would be no adverse environmental impact 

because of the pre-existing relief provisions that applied to the small refiner. We are also 

proposing that a refiner would 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, we are proposing 

that 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 we are proposing to allow 

such refiners to retain their 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 would 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.

We request comment on whether or not these provisions remain appropriate. 

 

417 See, for example, 69 FR 39051 (June 29, 2004).
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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. We are proposing a net crude throughput threshold of no 

more than 75,000 bpcd based on the highest throughput in calendar years 2010 or 2011 as 

the basis for receiving small volume refinery status. We request comment on whether or 

not another threshold would be more appropriate.

We are proposing that refiners would need to include the following in their 

applications:

 Proof that the refiner produced gasoline from crude oil during the 2011 

calendar year.

 Proof that the refiner owned and operated the refinery during the period from 

January 1, 2011 through December 31, 2011.

 The refinery’s total crude throughput as reported to EIA for each of calendar 

years 2010 and 2011. Again, we would presume that the information 

submitted to EIA is correct. In cases where a refiner disagrees with this 

information, the refiner could petition EPA with appropriate data to correct 

the record when the refiner submits its application for small volume refinery

status. EPA could 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 was true to the best of his/her knowledge and that the 

company owned the refinery as of January 1, 2011.

5. Attest Engagements, Violations, and Penalties

We are proposing to retain the 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 used in other EPA fuels programs for attest 

engagements. The violation and penalty provisions applicable to today’s proposed 

program would be very similar to the provisions currently in effect in other gasoline 

programs as well. We request comment on the need for additional attest engagement, 

violation, penalty, or any other compliance and enforcement related provisions specific to 

the proposed Tier 3 program.
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6. Special Fuel Provisions and Exemptions

The following paragraphs discuss several provisions and exemptions for gasoline 

that we are proposing would apply in special circumstances.

a. Gasoline Used in Military Applications

In our diesel fuel program, we provided an exemption for diesel fuel used in 

tactical military vehicles and nonroad engines and equipment with a national security

exemption (NSE) from the vehicle and engine 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 would also be 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), these 

applications need to be fueled on the same fuel as those with an NSE. We are proposing 

this exemption, however we request comment on whether or not the exemption would be 

needed under the proposed Tier 3 gasoline program.

b. Gasoline Used in Research, Development, and Testing

Similar to other EPA fuels programs, we are proposing to allow 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 proposed Tier 3 program. Thus, we are proposing 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 would be required to 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 could be granted at the discretion of EPA, with the condition 

that EPA could withdraw the exemption in the event the Agency determines the 

exemption is not justified. In addition, an exemption based on false or inaccurate 

information would be considered void ab initio. Gasoline subject to an exemption would 

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 non-exempt gasoline, identification of the exempt gasoline on PTDs, and 

pump labeling.
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c. Gasoline for Export

Gasoline produced for export, and that is actually exported for use in a foreign 

country, would be considered exempt from the fuel content standards and other 

requirements of this proposed rule. Such gasoline would be considered as intended for 

use in the U.S. and subject to the proposed standards unless it is designated by the refiner 

and the PTD states that the gasoline is for “export only”. Gasoline intended for export 

would be required to be segregated from all gasoline intended for use in the U.S. 

Distributing or dispensing such fuel for domestic use would be illegal.

d. Other Special Provisions and Potential Exemptions

We are proposing provisions for Alaska that would allow the refinery gate and 

downstream caps to remain at the current Tier 2 80-ppm and 95-ppm levels, respectively, 

should the caps be lowered to 50 and 65 ppm (per Section V.A.3).

Additionally, in previous 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 request comment on whether or not such exemptions would be 

needed for this program.

G. Statutory Authority for Proposed Tier 3 Fuel Controls

We are proposing 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)]. We are proposing 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 159 
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million people currently live in counties exceeding a NAAQS.418 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.419 A more detailed discussion of 

the health and environmental effects of these pollutants is included in Section II.B. As 

discussed in this section, 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, cost-effective 

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 and the impact on fuel supply. As discussed in 

Section V.A, we have concluded that these reductions are feasible in the lead time 

provided and should not have an adverse impact on the adequacy of gasoline fuel supply 

to meet demand. For more on the feasibility of the proposed fuel program, refer to 

Chapter 4 of the draft RIA.

As discussed in Section III, EPA also evaluated the emissions reductions from 

pre-Tier 3 vehicles that would be achieved by controlling gasoline sulfur levels. These 

reductions are significant and contribute to the total monetized health benefits. EPA also 

evaluated the cost per ton of emissions reduced for the proposed program, of which the 

10-ppm sulfur standard is a part. As can be seen in Section VII.D, the program is very

cost-effective in 2030. Even in 2017, when the emission reductions are almost entirely

due to the sulfur standards (and the costs are attributed to both the fuel and vehicle 

standards), the cost-effectiveness of the program is reasonable. 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 

proposed standards, refer to Chapter 8 of the draft RIA. 

The control of gasoline sulfur down to 10 ppm provides significant reductions in 

harmful emissions. The fuel program is cost-effective and produces benefits to public 

health and welfare whose value significantly outweighs the costs. These reductions can 

be achieved in a manner that is technologically feasible, and will not disrupt fuel supply.

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 

 

418 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.

419 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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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 

impact from motor vehicle engines, which are impacted by gasoline sulfur, is described 

in more detail in Chapter 6 of the draft 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 proposing Tier 3 emissions standards for motor 

vehicles under section 202. In order to meet these more stringent standards, the program 

requires a reduction in the sulfur content of gasoline to the 10-ppm annual average. 

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 proposed in this rule. EPA is 

proposing to 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 engines and California’s Low 

Emission Vehicle (LEV III) program. 

Section IV describes the substantial adverse effect of high gasoline sulfur levels 

on the emission-control devices or systems for Tier 3 vehicles and engines meeting the 

proposed emission standards. As discussed in Section IV.A.6, 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 nitrogen oxides 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 systems. The nature of sulfur 

interactions with washcoat materials, active catalytic materials and catalyst substrates is 

complex and varies with catalyst composition and 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. 

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 
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effects of fuel sulfur levels on catalyst active materials and catalyst efficiency. However, 

it cannot completely eliminate the effects of sulfur poisoning. 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 fuel sulfur levels will bring emission benefits unachievable by catalyst regeneration 

procedures alone. Furthermore, regular operation at these temperatures and at rich air-tofuel ratios is not desirable, for several reasons. 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. Additionally, it is not always possible to maintain these catalyst 

temperatures (because of cold weather, idle conditions, light load operation) and the rich 

air-to-fuel ratios necessary can result in increased PM, NMOG and CO emissions. 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. 

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 (in terms of percent conversion efficiency) 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 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.

In 2005, EPA and several automakers jointly conducted a program that examined 

the effects of sulfur and other gasoline properties, benzene, and volatility on emissions 

from a fleet of nine Tier 2 compliant vehicles. Subsequently, EPA conducted a much 

more extensive study of the effects of sulfur on emissions from Tier 2 vehicles. These 

studies demonstrate that emissions from Tier 2 vehicles continue to be very sensitive to 

gasoline sulfur levels below the current 30-ppm average standard. For more on the 

estimated emission impacts, refer to Section III.B. 

Furthermore, vehicles already capable of meeting the proposed Tier 3 standards 

have been found to be extremely sensitive to the effects of sulfur. A Chevy Malibu was 

tested and found to be able to meet the proposed Tier 3 standards on low-sulfur gasoline, 

but following operation on higher-sulfur gasoline, its emission levels exceeded the 

standard. As explained in Section IV.A, following operation over 2 FTP cycles on 33 

ppm sulfur fuel, NOX emissions alone were more than double the proposed Tier 3 30 

mg/mi NMOG+NOX standard. 

Overall, the Tier 3 Program would reduce fleet average NMOG+NOX emissions 

by over 80 percent. The feasibility of the proposed 30 mg/mi NMOG+NOX fleet average 

standard depends on a degree of emissions control from exhaust catalyst systems that will 
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require gasoline at 10 ppm sulfur or lower. The most likely control strategies would 

involve using exhaust catalyst technologies and powertrain calibration primarily focused 

on reducing cold-start emissions of NMOG and on 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 would allow sufficient NMOG 

compliance margin to allow vehicles to meet the combined NMOG+NOX emissions 

standards for the full useful life.

Achieving the proposed Tier 3 emission standards would require very careful 

control of the exhaust chemistry and exhaust temperatures to ensure high catalyst 

efficiency. The impact of sulfur on oxygen storage components in the catalyst makes this 

a challenge even at relatively low (10 ppm) gasoline sulfur levels. 

The negative impact of gasoline sulfur on NOX, NMOG and air toxic emissions 

occurs across all vehicle categories. However, the impact of gasoline sulfur on NOX

emissions control of catalysts in the fully-warmed-up condition is particularly of concern 

for larger vehicles. Manufacturers face the most significant challenges in reducing coldstart NMOG emissions for these vehicles. Because of the need to reach near-zero NOX

levels, 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 low enough to comply with the 30 mg/mi fleet-average standard. These 

vehicles represent a sufficiently large segment of light-duty vehicle sales now and in the 

foreseeable future that their emissions could not be offset (and thus the fleet-average 

standard achieved) by certifying vehicles to bins below the fleet average. Any

degradation in catalyst performance due to gasoline sulfur would reduce or eliminate the 

margin necessary to ensure in-use compliance with the proposed Tier 3 emissions 

standards. Certifying to a useful life of 150,000 miles vs. the current 120,000 miles 

would further add to manufacturers’ compliance challenge for Tier 3 large light trucks 

(Refer to Section IV.7.b for more on the useful life requirements.) 

The impact of gasoline sulfur poisoning on exhaust catalyst performance and the 

relative stringency of the Tier 3 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.A.2, the proposed 10-ppm standard for 

sulfur in gasoline represents the lowest practical limit from a standpoint of fuel 

production, handling and transport. While lowering gasoline sulfur to levels below 10 

ppm would help ensure in-use vehicle compliance with the Tier 3 standards, the Agency

believes that a gasoline sulfur standard of 10 ppm would allow compliance with a 

national fleet average of 30 mg/mi NMOG+NOX. The level of the Tier 3 standards was 

considered in light of a 10-ppm average sulfur level for gasoline. Not only should a 10-

ppm sulfur standard enable vehicle manufacturers to certify their entire product line of 

vehicles to the Tier 3 fleet average standards, but based on the results of testing both Tier 

2 vehicles and SULEV vehicles as discussed above, reducing gasoline sulfur to 10 ppm 

should enable these vehicles to maintain their emission performance in-use over their full 

useful life.
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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 emissioncontrol 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 below, 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 elsewhere in this 

document. The draft 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-effectiveness 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 proposed emission standards without the application of the kind of 

emissions control technology discussed in this proposal.

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 proposed 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 

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. The proposal basically extends various controls 

on gasoline to DFE, other oxygenates, butane, and gasoline additives. The reasons for 
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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 proposing new Tier 3 vehicle standards and new gasoline sulfur 

standards, we are also proposing and seeking comment on a number 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 proposed Tier 

3 vehicle and fuel standards, while others deal with other aspects of EPA’s existing 

vehicle and fuel regulations.

EPA is also proposing to synchronize a number of different reporting deadlines 

under various regulations affecting transportation and motor vehicle fuels and fuel 

additives. This action would reduce regulatory burdens by aligning reporting deadlines 

across several programs and would lay the foundation for the overall goal of combining 

various fuels reports together into a single, simplified electronic format. Amendments to 

40 CFR Parts 79 and 80

The following sections discuss our proposed changes to regulations in 40 CFR 

part 79 and part 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 could benefit from clarification and/or streamlining. 

With regard to regulatory streamlining, the majority of these items involve 

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

and decreasing the frequency and/or volume of reporting burden where data is either no 

longer needed or is redundant in light of other EPA fuels programs. In general, we 

believe that these changes would reduce burden on industry with no expected 

environmental impact. We believe that the regulatory streamlining items that we are 

proposing are changes that are straightforward and that should be made quickly. There 

are also additional items that would need further consideration and discussion, such as a 

new fuels program compliance structure, as discussed below in Section VI.A.1.b. We are 

also requesting comment on expanding the downstream butane blending provisions to 

allow for pentane blending, as discussed in Section VI.A.4.

1. Regulatory Streamlining

a. Summary of Proposed Amendments

Below is a table listing the provisions that we are proposing to amend in today’s 

action. We have provided additional explanation for those amendments that warrant 

additional explanation below.

Table VI-1 Summary of Proposed Regulatory Streamlining and Technical 

Amendments

Section Description
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Varied Various sections amended to update references to test methods 

(see Section 0).

79.5 Revises periodic reporting requirements.

80.2 Revises and adds definitions.

80.8 Amended to update sampling test methods, and to state to 

which fuels §80.8 applies.

80.10 Added to allow for de minimis changes in compliance reports 

that would not require a resubmission of compliance reports 

when a minor discrepancy of a few barrels is uncovered.

80.46 Revises measurement of RFG fuel parameters.

80.47 Revises Performance-Based Test Method Approach.

80.65 Amended to reduce complex model test parameters and 

reporting.

80.65(f)(5) Added to allow for designation of an alternative lab.

80.75 Revises RFG reporting requirements.

80.82 Amended to apply butane blending provisions to entire part 80 

and to revise RVP test method.

80.101 Revises measurement of conventional gasoline fuel parameters.

80.105 Amended to require identification of test methods used and 

revises reporting requirements.

80.161(b)(1)(ii)(A)(2) Amended to allow an alternative gasoline detergent certification 

option.

80.161(b)(1)(ii)(A)(3) Added to allow an alternative detergent certification option.

80.161(b)(2) Amended to address the submission of gasoline detergent 

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 would be required under the 

alternative detergent 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 detergent 

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 

detergent certification option.

80.163(a)(1)(iii) Amended to allow use of the alternative gasoline detergent 

certification option.

80.164(a) Amended to reference the test fuel requirements under the 

alternative gasoline detergent certification option.

80.165 Amended the introductory paragraph to accommodate the 
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alternative deposit control test procedures and standards under 

the alternative gasoline detergent certification option.

80.167(a) Amended the introductory paragraph to specify how 

confirmatory testing would be conducted for additives certified 

under the alternative gasoline detergent certification option.

80.176 Added to specify the certification test procedures and standards 

under the alternative gasoline detergent certification option.

80.177 Added to specify the certification test fuels under the alternative 

gasoline detergent certification option.

80.178 Incorporates standards and test methods by reference.

80.330 Revises sampling and testing requirements.

80.370 Amended to require identification of test method used and 

revises reporting requirements.

80.511 Revises per-gallon and marker requirements.

80.572 Revises labeling requirements.

80.573 Revises labeling requirements.

80.574 Revises labeling requirements.

80.580 Incorporates test methods by reference.

80.585 Revises test method approval process.

80.604 Revises 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 Revises 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 Revises 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.
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80.1354 Revises reporting requirements for gasoline benzene program.

80.1451 Revises RFS reporting requirements.

i. Amendments Related to Reduction of Testing for Complex Model Fuel 

Parameters

In §§80.65 and 80.75, we are proposing to streamline and reduce the RFG and 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 parameter listed in §80.65 must be tested for every batch and 

each parameter must be reported for every batch. No monthly compositing of batch 

samples is allowed for any parameter. For conventional gasoline, monthly compositing 

and batch reporting based on those monthly composites is allowed for all parameters 

except sulfur and benzene. However, with the phasing out of complex model standards, 

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 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 until 2015 for CG MSAT1 compliance.420 Currently, there are 17 

complex model parameters on the RFG/anti-dumping batch report. We are proposing to 

eliminate reporting for American Petroleum Institute (API) gravity. In addition, 

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. In addition, we are proposing to reduce testing and reporting as 

follows: For both RFG and conventional gasoline we propose to eliminate the 

requirement to test and report API gravity for batch certification purposes. For winter 

RFG, we propose to eliminate the requirement to test and report the following parameters 

on an every batch basis and instead allow testing and reporting of monthly composites:

aromatics, distillations and olefins. Winter sulfur and benzene would continue to be 

tested and reported on an every batch basis. All summer complex model parameters 

would still be required to be tested and reported on an every batch basis. For 

conventional gasoline, since the regulations already allow for testing and reporting most 

parameters on a monthly composite basis, the only significant change would be to 

eliminate the batch certification testing and reporting for API gravity. 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

 

420 61 FR 17230 (March 29, 2001).
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composite testing and reporting except for sulfur and benzene, and oxygenate, where 

applicable). The values for aromatics, olefins, and distillation terms may continue to be 

determined from monthly composites. These changes would substantially reduce the 

testing and reporting associated with each batch. We request comment on this reduced 

testing scheme.

ii. Amendments Related to Reporting

EPA is proposing to amend 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. EPA’s goal is to simplify

reporting and reduce the number of hours parties spend preparing and submitting reports. 

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.

Currently under 40 CFR parts 79 and 80, there are ten separate cyclical reporting 

dates each year (eleven in a leap year). This proposal would amend these deadlines so 

that all affected programs use the same four dates. Programs that would be affected by

this proposal 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), and the Renewable Fuel 

Standard program (40 CFR part 80 subparts K and M). We are proposing that reporting 

deadlines would be standardized as follows: June 1, for all reports covering quarter 1 of 

the compliance year; September 1, for quarter 2; December 1, for quarter 3; and March 

31 for quarter 4. End of year compliance reports would also be due on March 31.

These proposed changes would either delay or maintain current deadlines for 

nearly all required reports. Deadlines for all other annual reports would either be 

maintained if they matched the new quarterly deadline, or extended to match the new 

quarterly deadline.

These proposed changes would not include “Attest Engagements” or reporting 

related to specific events under the Fuels Program, such as trading Renewable 

Identification Numbers (RINS) in EPA’s Moderated Transaction System (EMTS). All 

reporting deadlines for Attest Engagements and reporting specific events would remain 

the same.

Respondents would still have the option to report earlier than any given deadline. 

Additionally, these deadline changes would allow EPA to develop a single electronic 

format that would collect all required data and maximize the capability of electronic 

reporting with data reuse, no duplicate fields, and a user-friendly interface.
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We would also be correcting a typographical error in 40 CFR 80.1451(f)(2) and 

clarifying that reports are to be signed by the “responsible corporate officer.” 

Additionally, we would remove an incorrect reference under 79.5(a)(2). Amendments to 

Update 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. A 

number of relevant regulatory provisions currently have references to test methods that 

have since been revised and updated. We are proposing to update 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 (§§80.46(a)(1), 80.580(b)(2)), in gasoline 

and diesel fuel at the 500 ppm sulfur standard. ASTM test methods D5453, D6920, 

D3120 and D7039 are currently alternative test methods for measuring sulfur 

(§§80.46(a)(3)(i), 80.46(a)(3)(ii), 80.46(a)(3)(iii), 80.46(a)(3)(iv)) in gasoline. ASTM 

test method D5453 is also alternative test method for measuring sulfur (§80.580(c)(2)) in 

diesel fuel at the 500 ppm sulfur standard, as well as ASTM test method D4294. ASTM 

test method D6667 is currently the designated test method for measuring sulfur (§80.46 

(a)(2)) in butane. ASTM test methods D4468 and D3246 are currently alternative test 

methods for measuring the sulfur (§80.46(a)(4)(i), 80.46(a)(4)(ii)) content in butane. 

ASTM D1319 is currently the designated test method for measuring olefins (§80.46(b)) 

in gasoline and aromatics (§80.2(z)) in diesel fuel and is also allowed as an alternative 

test method for measuring aromatics (§80.46(f)(3)) in gasoline. ASTM D6550 is 

currently an alternative test method for measuring olefins (§80.46(b)(2)(i)) in gasoline. 

ASTM test method D5599 is currently the designated test method for measuring 

oxygenates (§80.46(g)(1)) in gasoline. ASTM test method D4815 is currently an 

alternative test method for measuring oxygenates (§80.46(g)(2)) in gasoline. ASTM test 

method D5769 is currently the designated test method for measuring aromatics 

(§80.46(f)(1)) in gasoline. ASTM test method D3606 is currently the designated test 

method for measuring benzene (§80.46(e)) in gasoline. ASTM test method D86 is 

currently the designated test method for measuring the distillation (§80.46(d)) of 

gasoline. ASTM test method D5191 is currently the designated test method for 

measuring the RVP (§80.46(c)) of gasoline. ASTM test method D976 is currently the 

designated test method for measuring the Cetane Index (§80.2(w)) of diesel fuel. 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 proposing to update 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 proposal to revise these test 
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methods would 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 International so that improvements in the test 

method’s procedures would ensure better operation for the user of the test method. Thus, 

EPA is proposing today to update 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 gasoline, ASTM D4294-10, alternative test 

method for sulfur in diesel fuel at the 500 ppm sulfur standard; (3) ASTM D5453-09, 

alternative test method for sulfur in gasoline and diesel fuel at the 500 ppm sulfur 

standard; (4) ASTM D6667-10, designated test method for sulfur in butane; (5) ASTM 

D4468-85(2006), alternative test method for sulfur in butane; (6) ASTM D3246-11, 

alternative test method for sulfur in butane; (7) ASTM D1319-10, 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; (8) ASTM D6550-10, alternative test 

method for measuring olefin content in gasoline; (9) ASTM D4815-09, alternative test 

method for measuring oxygenate content in gasoline; (10) ASTM D5599-00(2010), the 

designated test method for measuring oxygen content in gasoline; (11) ASTM D5769-10, 

the designated test method for measuring aromatics in gasoline; (12) ASTM D3606-10, 

the designated test method for measuring benzene in gasoline; (13) ASTM D86-11a, the 

designated test method for measuring distillation properties of gasoline; (14) ASTM 

D5191-10b, the designated test method for measuring the RVP of gasoline; (15) ASTM 

D976-06(2011), the designated test method for measuring the Cetane Index of diesel fuel; 

(16) ASTM D4057-06(2011), the manual sampling standard practice for petroleum and 

petroleum products; (17) ASTM D4177-95(2010), the automatic sampling standard 

practice for petroleum and petroleum products; (18) ASTM D5842-04(2009), the 

sampling standard practice for RVP of fuels; and (19) ASTM D5854-96(2010), the 

composite sampling standard practice for petroleum and petroleum products.

Table VI-2 Proposed Designated & Alternative ASTM International Analytical Test 

Methods Under RFG, CG & Diesel Motor Vehicle Fuel Programs

Fuel Parameter ASTM Analytical Test Method

Sulfur (gasoline) ASTM D2622-10, entitled “Standard Test Method for Sulfur 

in Petroleum Products by Wavelength Dispersive X-Ray

Fluorescence Spectrometry”

Sulfur (500 ppm diesel) ASTM D2622-10, entitled “Standard Test Method for Sulfur 

in Petroleum Products by Wavelength Dispersive X-Ray

Fluorescence Spectrometry”

Sulfur (gasoline) ASTM D5453-09, 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 (500 ppm sulfur 

diesel)

ASTM D5453-09, 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”
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Sulfur (gasoline) ASTM D3120-08, entitled, “Standard Test Method for Trace

Quantities of Sulfur in Light Petroleum Hydrocarbons by

Oxidative Microcoulometry”

Sulfur (500 ppm sulfur 

diesel)

ASTM D4294-10, entitled, “Standard Test Method for Sulfur 

in Petroleum Products by Energy Dispersive Xray

Fluorescence Spectrometry”

Sulfur (butane) ASTM D6667-10, entitled, “Standard Test Method for 

Determination of Total Volatile Sulfur in Gaseous 

Hydrocarbons and Liquefied Petroleum Gases by Ultraviolet 

Fluorescence”

Sulfur (butane) ASTM D4468-85(2006), entitled, “Standard Test Method for

Total Sulfur in Gaseous Fuels by Hydrogenolysis and 

Rateometric Colorimetry”

Sulfur (butane) ASTM D3246-11, entitled, “Standard Test Method for Sulfur 

in Petroleum Gas by Oxidative Microcoulometry”

Oxygen content 

(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 

(gasoline)

ASTM D4815-09, entitled “Standard Test Method for 

Determination of MTBE, ETBE, TAME, DIPE, tertiary-Amyl

Alcohol and C1 to C4 Alcohols in Gasoline by Gas 

Chromatography”

Olefins (gasoline) ASTM D1319-10, entitled “Standard Test Method for 

Hydrocarbon Types in Liquid Petroleum Products by

Fluorescent Indicator Adsorption”

Olefins (gasoline) ASTM D6550-10, entitled, “Standard Test Method for the 

Determination of Olefin Content of Gasolines by

Supercritical-Fluid Chromatography”

Aromatics (gasoline and 

diesel)

ASTM D1319-10, 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.

Aromatics (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 (gasoline) ASTM D3606-10, entitled, “Standard Test Method for 

Determination of Benzene and Toluene in Finished Motor and 

Aviation Gasoline by Gas Chromatography”

Distillation (gasoline) ASTM D86-11a, entitled, “Standard Test Method for 

Distillation of Petroleum Products at Atmospheric Pressure”

Reid Vapor Pressure 

(gasoline)

ASTM D5191-10b, entitled, “Standard Test Method for 

Vapor Pressure of Petroleum Products (Mini-Method)”
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Cetane Index (diesel) ASTM D976-06(2011), entitled, “Standard Test Method for 

Calculated Cetane Index of Distillate Fuels”

Manual Sampling of 

Petroleum and 

Petroleum Products

ASTM D4057-06(Reapproved 2011), entitled, “Standard 

Practice for Manual Sampling of Petroleum and Petroleum 

Products”

Automatic Sampling of 

Petroleum and 

Petroleum Products

ASTM D4177-95(Reapproved 2010), entitled, “Standard 

Practice for Automatic Sampling of Petroleum and Petroleum 

Products”

RVP Sampling for Fuels ASTM D5842-04(Reapproved 2009), entitled, “Standard 

Practice for Sampling and Handling of Fuels for Volatility

Measurement”

Composite Sampling of 

Petroleum and 

Petroleum Products

ASTM D5854-96(Reapproved 2010), entitled, “Standard 

Practice for Mixing and Handling of Liquid Samples of 

Petroleum and Petroleum Products”

iii.Amendments Related to Downstream Blending

Today’s proposed 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 

proposing changes that would allow refiners and importers to include oxygenate blended 

downstream of their facility and that would make these related sections consistent.

iv. Amendments for Previously Certified Gasoline

For benzene, we would also provide 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 the produced batch for blendstock that is blended 

into previously certified gasoline (PCG). We are proposing to add §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 test the PCG for 

benzene before addition of blendstock, test the combined blend of PCG and blendstock 

for benzene, 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 proposing to amend the regulations at §80.1235(a)(6) (and add 

§80.1347(a)(6), as mentioned) to allow refiners and importers that blend blendstock into 

PCG an alternative to directly test the blendstock for benzene. We expect that this would

ensure a positive benzene test result. Also, today’s proposal would clarify that regardless 
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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 proposing to amend 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.

Lastly, we are proposing to allow 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.421 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. Today’s rule 

proposes to amend the regulations to provide this alternative by adding a new §80.1349.

v. 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 proposing (at §80.65(f)(5)) that a facility 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 could 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).

vi. Amendments Related to De Minimis Reporting Changes

We are proposing for the correction of batch volume reports to allow for de 

minimis changes in reporting compliance that would not require a complete resubmission 

of compliance reports when a minor discrepancy of a few barrels is uncovered. This 

allowance for the correction of batch volume reports would apply to reporting for: RFG, 

anti-dumping, gasoline and diesel sulfur, MSAT2 and the RFS renewable volume 

obligation (RVO) (for RFS, this would only apply to the volume of fuels produced or 

exported that result in a RVO for obligated parties). We are proposing a new section 

80.10 to define de minimis, for the purpose of this allowance, as no more than 500 

gallons or by no more than 1 percent of the true batch volume in gallons, whichever value 

is less. We request comment on whether or not a different amount would be more 

appropriate.

 

421 70 FR 74561 (December 15, 2005).
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vii. Amendments Related to RFS2 Annual Report Date

Currently, the RFS2 final reporting date (last day of February) coincides with the 

RFG and Anti-dumping compliance deadline, which creates a staffing problem for 

regulated entities because the regulatory requirements are often handled by the same 

personnel. It was reported to EPA that this also creates an issue when small 

discrepancies in gasoline production or import volumes are realized, and can potentially

trigger an increased RFS RVO and an ensuing scramble to obtain the necessary

Renewable Identification Numbers (RINs) in real time. Delaying the RFS reporting date 

until after volumetric auditing would address this situation and would have no impact on 

emissions, air quality or compliance with the standard. As such, we are proposing to 

change the RFS2 reporting date in §80.1451 to March 31. EPA is also seeking comment 

on whether the ability to transfer RINs in EMTS for satisfying RVOs under the previous 

compliance year should be extended from the last day of February to March 31 as well.

viii. Acceptance of Alternate Test Data Under the Gasoline Deposit Control 

Program

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.422 Several major gasoline marketers have adopted Top Tier for their gasoline. 

It is widely accepted that conformance with the Top Tier intake valve deposit (IVD) and 

fuel injector deposit (FID) control testing requirements is more challenging than 

complying with the EPA IVD and FID testing requirements. Yet additive packages must 

still be certified to EPA’s less stringent standards on older test procedures. We believe 

that EPA could accept IVD/FID test data that complies with the Top Tier requirements in 

place of IVD/FID data that complies with the current EPA testing requirements without 

jeopardizing the emissions benefits from EPA’s deposit control program. We are 

proposing that test data that complies with the Top Tier IVD performance standards at 

section 1.3.1 could be used to satisfy EPA’s IVD control requirements. We are also 

proposing that test data that complies with the Top Tier FID performance testing 

standards at section 1.3.3 could be used to satisfy EPA’s FID control requirements. We 

believe that this allowance would provide significant saving to industry from reduced 

deposit control testing while maintaining the emissions benefits of EPA’s gasoline 

deposit control program. These changes are being proposed 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.

b. 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 

 

422 The industry established “Top Tier” deposit control standards can be found at 

http://www.toptiergas.com/deposit_control.html. EPA’s deposit control requirements are contained in 

§§80.140 through 80.174.
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include gasoline volatility (RVP), reformulated gasoline and anti-dumping, sulfur control 

(which the Tier 3 program proposed today would 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 

burdensome 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 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 are proposing 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 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 proposed today. 

EPA expects that streamlining would result in more efficient and less costly 

compliance determinations for affected parties while maintaining the environmental 

benefits of the programs. Since 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, we are not proposing such changes today. However, EPA 

requests comments 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.

2. Subpart I Technical Amendments

Table VI-3 40 CFR Part 80 Subpart I (Diesel Fuel) Technical Amendments

Section Description

80.572(a) 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 motor vehicle diesel fuel.

80.584(b)(3)(i) Amended to correct typographical error (“notc” to “not”).
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We are proposing to remove 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, so we are also requesting comment on the removal of this 

labeling requirement. Note that if highway diesel fuel pump labels are no longer required 

by the regulations, retail and wholesale purchaser-consumer facilities would be free to 

continue labeling to eliminate confusion if they so choose.

3. Performance-Based Measurement Systems (PBMS)

Table VI-4 PBMS-Related Technical Amendments

Section Description

80.46 Amended to allow for performance-based approaches for 

measuring gasoline parameters.

80.47 Added to extend the performance-based approach to other 

parameters besides diesel sulfur.

80.101(i)(1)(i)(A), 

(i)(3)(i)(C), (i)(3)(ii)(C)

Amended to allow for performance-based approaches for 

measuring gasoline parameters.

80.330(c)(1), (d)(1), 

(d)(2)

Amended to allow for performance-based approaches for 

sampling and testing.

80.370(a)(7)(iv) Amended to require identification of the test method used to 

measure the sulfur content of a batch.

80.585(a) and (d)(4) Amended to state the process for approval of test methods 

prior to and after adoption of PBMS for all fuel programs.

80.1348 Amended to state the sample retention requirements prior to 

and after adoption of PBMS for all fuel programs.

80.1354(b)(2) Amended to require identification of the test method used to 

measure the benzene concentration of a batch.

Consistent with EPA’s performance-based measurement system (PBMS) 

initiative (as discussed below), today we are proposing a PBMS for those chemical and 

physical properties of motor vehicle fuels regulated by EPA’s motor vehicle fuel 

programs. Specifically, these are gasoline properties at §80.46, gasoline sulfur at 

§§80.195 and 80.1603, and diesel fuel properties at §80.2(z). This PBMS sets forth 

procedures and criteria by which laboratories making measurements to demonstrate 

compliance with fuels regulations may qualify alternative analytical test methods to those 

required in the regulations. It also sets minimum statistical quality control (SQC) 

requirements, following standard industry practices, by which laboratories must maintain 

and document the precision and accuracy of analytical methods used in the context of 

these programs. EPA envisions that the proposed 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 fuel properties 
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while not making any reductions in the emission benefits that result from motor fuel 

programs. It should also provide cost savings to the regulated industry by providing 

rapid access to newly-developed test methods with speed and ease of analysis. Some of 

these newer methods use smaller quantities of consumables and less-expensive 

instrumentation that are easier to automate, thus reducing both operating costs and 

environmental impact.

a. Background

Refiners, importers and oxygenate blenders producing RFG, conventional 

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 requirements423) in 40 CFR part 80. Table VI-5 lists the 

parameters/fuels and their corresponding designated test methods that we are proposing 

to update.

Table VI-5 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

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

 

423 See §§80.580, 80.584 and 80.585.
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In addition to the designated analytic methods for the parameters mentioned 

above, EPA has specified alternative test methods for some parameters. These alternative 

test methods may be used in lieu of the corresponding designated test methods, provided 

that all test results are correlated to the appropriate designated test methods. Alternative 

test methods have not been established for all regulated motor vehicle fuel parameters, 

however. Specifically, alternative test methods have been established for measuring the 

gasoline properties of aromatic content,424 oxygenate content,425 olefin content,426 and 

sulfur content427 as well as sulfur in butane428. Currently, if a regulated party wishes to 

use an alternative test method that is not already approved, it must petition the Agency, 

and EPA must approve the use of this alternative method through a rulemaking process 

that on average, may take more than a year to complete.

Approving new methods through rulemaking has been identified as a barrier to 

the use of innovative analytical test methods. In order to address these concerns and 

similar ones in other media areas, the Agency’s Environmental Monitoring Management 

Council established a workgroup of scientists representing EPA’s Headquarters and 

Regional offices to consider establishing a performance-based approach to specifying 

analytical testing requirements. On the recommendations of the workgroup, the Agency

decided to incorporate the PBMS approach into its programs, to the extent feasible.

EPA’s practice, in recent rulemaking activities, of aligning its prescribed methods 

with those published by Voluntary Consensus-based Standards Bodies (VCSBs)429 is 

almost consistent with the PBMS policy and with the National Technology Transfer and 

Advancement Act (NTTAA).430 For example, in the nonroad diesel rulemaking, which 

controlled the sulfur content of diesel fuel,431 EPA required only that laboratories 

demonstrate their test methods’ ability to meet a set performance criteria rather than 

prescribing that a single specific method be used. Today’s proposal extends the diesel 

sulfur qualification approach to the chemical/physical properties measured in other motor 

vehicle fuel programs, with modifications appropriate to accommodate the differences 

among the fuel parameters.

b. Overview of Proposed Program Requirements

In a June 29, 2004 rulemaking, EPA specified a performance-based approach to 

measuring diesel sulfur at 15 ppm and 500 ppm and removed the previous requirement of 

 

424 ASTM D 1319-03ε1 (see §80.46(f)(3)).

425 ASTM D 4815-04 (see §80.46(g)(2)).

426 ASTM D 6550-05 (see §80.46(b)(2)(i)).

427 ASTM methods D 5453-08a, D 6920-07, D 3120-06ε1, and D 7039-07 (see §§80.46(a)(3)(i) through 

80.46(a)(3)(iv)). 

428 ASTM D 4468-85 (reapproved 2000) and ASTM D 3246-96 (see §§80.46(a)(4)(i) and 80.46(a)(4)(ii)).

429 ASTM International (ASTM) is one such organization.

430 Public Law 104-113, 104th Congress, March 7, 1996, H.R. 2196.

431 69 FR 38958, June 29, 2004. This rulemaking used standard materials with known chemical 

composition to evaluate the accuracy of candidate test methods.
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particular designated and alternative methods for 15 ppm diesel sulfur.432 We decided, in 

that rulemaking, to offer users two approaches to selecting test methods for diesel sulfur 

at the 500 ppm level. The first of these was to use either the designated test method or 

specific alternative test methods.433 The second option was to meet performance based 

requirements similar to those adopted for 15 ppm diesel sulfur.434 We are proposing 

today to extend the performance-based approach to method selection and qualification to 

other parameters besides diesel sulfur, with modifications appropriate to accommodate 

the differences among the fuel parameters.

Specifically, we are proposing requirements that laboratories would be required to 

demonstrate the precision435 and accuracy436 of chosen fuel parameter measurement 

methods. Once implemented, this proposal 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 prescribed criteria rather than specific 

methods,437 and (3) require all laboratories making regulatory measurements to establish 

and maintain a statistical quality control program. EPA intends that the measurement 

system resulting from this proposal would make no compromises on precision or 

accuracy relative to the system that exists under current regulations. We intend to 

incorporate the standards and practices of Voluntary Consensus Standards Body (VCSB) 

organizations wherever feasible.

Today’s PBMS approach applies to the qualification of analytical test 

instrumentation and methods used to measure various characteristics of individual fuel 

samples. It does not apply to sampling methods or in-line blending methods. While inline blending certainly includes the use of analytical measurements, it is broader in scope 

than this proposal. Including in-line blending methodologies in this proposed rulemaking 

would raise issues that could not be adequately addressed in the context of this proposed 

rulemaking. Furthermore, in-line blending already has a certification process, as 

specified in regulations at §80.65(f), that sets forth qualification criteria that take into 

account the unique combinations of sampling, control, and analysis that are involved with 

in-line blending. However, we seek comment on potentially expanding our PBMS to 

include sampling or in-line blending methods.

 

432 See §§80.584 and 80.545.

433 See §80.580(c)(2).

434 See §§80.584(a)(2), 80.584(b)(2)(i) through 80.584(b)(2)(iii), and 80.585.

435 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.

436 Accuracy – the closeness of a single measurement to its true value of what is being measured.

437

 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.
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c. How Can We Establish the Accuracy of the Measurement System (All 

Qualified Methods/Installations) For Each Parameter?

We are proposing to group the gasoline and diesel fuel parameters that must be 

measured (e.g., aromatics, sulfur, etc.), into two categories. These categories depend on 

whether it is feasible to construct and use gravimetric standards438 for defining the 

parameter and thus determining the accuracy of a measurement method. For some 

parameters it is difficult or perhaps impossible to make gravimetric standards. This is 

particularly true where the parameter is actually a class of chemical compounds 

(themselves containing multiple chemical compounds) that may have a very large 

number of members (e.g., aromatics in gasoline). Use of gravimetric standards for 

establishing accuracy may also be hindered if many of the potential measurement 

methods are sensitive to the chemical composition of the material that the analyte is 

added (often called the “matrix”) and are thus prone to being “confused” into giving 

inaccurate answers. Where these two problems are not present, the use of gravimetric 

standards is the ideal way to establish the accuracy of the analytical test method. We will 

describe these as “absolute” parameters. The accuracy qualification test for a method 

measuring such parameters should center upon its being able to get the “right” answer for 

one or more gravimetric standards.

To establish the accuracy of methods measuring each parameter where 

gravimetric standards hindered, we are proposing to retain an EPA-prescribed reference 

method or “designated method” that would, in effect, define the parameter as “parameter 

X is, for federal regulatory purposes, whatever method Z measures.” Parameters that 

require such treatment will be described as “method-defined” parameters. Establishing 

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. This approach is often 

referred to as correlating the new method with the designated method. In other words, 

measurements from the new method (the “candidate” for qualification) would be used to 

predict the measurements that the designated method would get on the same fuels (with, 

perhaps, some offset or adjustment equation applied) and then these predictions would be 

compared with the actual measurements made from those fuels by the designated method. 

If the predictions are consistently close to the designated method measurements and 

evenly distributed above and below these reference values, then the laboratory and the 

method it proposes to use would have a good case for qualification with regard to 

accuracy. Such a correlative approach to qualification is dependent for its workability

upon the test fuels used to establish the correlation. Such fuels 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

 

438 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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some new refining process) for which the correlation equation derived earlier is not 

accurate and where the predictions of the designated method’s results are quite erratic 

and inaccurate. 

In addition to the dependence of the method-defined approach upon the choice of 

fuels for establishing the correlation to the designated method, this approach also greatly 

elevates the importance of the designated method that is used. An increasingly obsolete 

designated method might need to be changed for practical reasons, but adoption of a new 

designated method could bring about a de facto change in the standard for the parameter 

in the absence of a prescribed correction equation designed to align the new designated 

method with the old. While the gravimetric approach to measurement has its own 

problems, it is free of the difficulties associated with any particular method.

Our classification of parameters into the absolute or method-defined categories is 

not entirely straightforward. Of the parameters subject to this proposal, only those with 

sulfur as the analyte fall into the absolute category. 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. 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 even more 

amenable to the absolute approach, since butane is a single compound rather than a 

constantly varying mixture of many compounds. We also note, as mentioned before, that 

the diesel sulfur rule used the absolute approach. For these reasons we are proposing to 

treat gasoline sulfur and sulfur in butane as absolute parameters. 

Beyond these two sulfur parameters, classification becomes more difficult. 

Where the analyte is a class of compounds, like aromatics, the construction of a 

gravimetric standard would have to be done by use of an agreed-upon conventional 

recipe that includes some group of the compounds in the class in proportions that 

approximate to what is found in the actual fuels that a method will measure. If the class 

has relatively few compounds and they are all available in reasonably pure form, then 

they could all be included in the standard, leaving only the issues of their respective 

concentrations (likely to vary among real fuels) and the question of “matrix effects” as 

discussed above. Where the class of compounds has many members and not all could be 

included in an artificially constructed standard, we are left with the question of which 

ones can be omitted on grounds that they are likely to occur only in very small 

concentrations and/or are not particularly important in emission formation. The result of 

these exclusions, for certain parameters, would likely be a directional bias toward 

underestimating the prevalence of the target class of compounds. The likely size of the 

bias will vary among parameters and among fuels on which measurements are made. 

Use of a complex recipe for such standards, where possible, may minimize the bias, but 

may add to the costs and difficulty of formulating a standard representative of all fuels.

The distillation parameters (T50 and T90) seem to be largely resistant to a 

gravimetric approach that relies on pure compounds instead of the smooth curve that 

results from simple distillation of complex mixtures like gasoline and diesel fuel. Such 
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gravimetric standards, incorporating only a very limited number of compounds out of 

practical necessity, would be likely to yield a kind of stair-step curve.

Given these logical and practical difficulties with using a gravimetric approach to 

qualifying methods for parameters other than sulfur, EPA is today proposing that the 

method-defined or correlative approach be used for all parameters other than sulfur. We 

are especially interested in receiving comment on our categorization of fuel parameters as 

either absolute or method defined.

d. How Would Analytic Methods be Evaluated for Qualification? 

i. General Provisions: To Which Methods and Which Parties do the Proposed 

Requirements Apply?

As discussed above, EPA believes that the interests of measurement quality are 

best served by evaluating most method installations for qualification at the level of 

individual laboratories instead of individual instruments. This approach was used in 

regulating diesel sulfur. We are proposing to require laboratories to qualify all methods 

that will be used to make measurements for regulatory purposes. EPA does not believe 

that a relatively simple qualification test will ensure continued measurement quality, but 

rather that this will greatly reduce the likelihood of a laboratory undertaking important 

measurements without some assurance that the instrument is in working order, that at 

least one operator439 in the laboratory understands the method for its use, and that it can 

be made to perform to meet acceptable criteria. We seek comment on requiring 

laboratories to qualify all methods used to take measurements for regulatory purposes.

ii. How Would Laboratories Demonstrate the Precision and Accuracy of 

Methods for Measuring “Absolute” Parameters and Thus Qualify the 

Methods for Use?

We are proposing to require a separate qualification for test methods used to 

measure gasoline sulfur. As mentioned previously, the Agency has successfully

implemented performance based requirements for sulfur in diesel fuel. The test methods 

typically used for gasoline sulfur (one of the two parameters we are proposing to consider 

absolute, as discussed above) are also frequently used for diesel sulfur and the ASTM test 

method designations for both are the same. However, examination of test method 

descriptions points toward substantial differences in how the test methods are used in the 

different matrices. One example is a requirement for recalibration when matrices shift. 

While we considered the possibility of allowing the diesel sulfur qualifications to be used 

 

439 The intent behind the qualification process is to demonstrate the facility’s capability with the method. 

Accordingly we are not proposing 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 are not proposing 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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also for gasoline sulfur, we believe the differences between a diesel fuel matrix and 

gasoline fuel matrix may be too great to permit such a sweeping exemption from 

qualification requirements. The process of reworking the test methods to measure 

gasoline sulfur will, in many cases, generate most of the data needed for qualification, 

and thus will not represent a major additional effort. So, despite the fact that ASTM test 

methods are the same for gasoline and diesel, we are proposing to require separate 

qualification for test methods used in measuring gasoline sulfur.

Operational Description. We are proposing to require applications for 

qualification to include a complete operational description of the test method in question. 

A VCSB publication would satisfy this requirement for methods published by such 

organizations as ASTM. 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. 

Precision Qualification. We are proposing requirements for precision 

qualification that are similar to requirements set forth in the nonroad diesel sulfur rule. 

That rule imposed a maximum value for the standard deviation440 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. 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. 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 

consider it to be reasonable on its face, as well as having proven to be workable in 

practice, and we have therefore retained it in this proposal. We request comments on the 

selection of a test method’s repeatability to use as the basis of the qualification. 

Gasoline Sulfur Criterion. We are proposing to use the ASTM repeatability 

standard deviation factor as discussed above from ASTM D7039-07 to set the precision 

criteria for gasoline sulfur. We note that there is a designated test method and four 

alternative test methods for gasoline sulfur. The larger repeatability among the test 

methods currently allowed for sulfur in gasoline is for ASTM D6920-07. This was 

obtained only when the substantially more variable of the two instrument models 

included in a small inter-laboratory study was included. Since the most variable 

instrument model had a repeatability of nearly twice that of the other test methods and 

over four times that of the other instrument model for the same method, we believe that

ASTM D6920-07 should be represented, for this purpose, by the instrument model 

yielding the better performance of the two. Given that decision, ASTM D7039-07 is left 

 

440 Where the standard deviation is estimated from a sample of the population (formula uses “N-1” in the 

denominator).
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with the largest repeatability of these test methods. And we are proposing to use its 

repeatability (1.76 ppm at 10 ppm) to set the precision criterion for this parameter. Thus 

the maximum allowable standard deviation of the twenty test results on a 10 ppm

gasoline would be 0.95 ppm441. Since we do not propose to prescribe the parameter level 

for the fuel used for these precision tests, 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. 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.

Sulfur in Butane Precision Criteria. There are three test methods currently

allowed for measuring the sulfur content of butane for blending into gasoline. A new 

designated test method was adopted for this parameter (ASTM D6667-10)442 because the 

previous primary test method, D3246-11, had become somewhat obsolete. Given that 

D3246-11 is no longer widely available,443 though still an allowed alternative test 

method, and that the range of D4468-85 (reapproved 2006) extends only to 20 ppm, we 

are proposing a precision criterion based on the repeatability of D6667-10. This test 

method’s repeatability at the 10 ppm level is 1.15 ppm, so the calculations used above 

with gasoline sulfur yield an upper limit for the standard deviation of the 20 tests for 

sulfur in butane of 0.62 ppm.

Temporal Distribution of Precision Tests. With regard to spacing of the 20 

precision tests, we are proposing 7 or fewer tests per week and 2 or fewer tests per day. 

We believe this would prevent weekend testing while also precluding practices such as 

conducting one test on the first day and 19 tests on the 20th day. We believe that 

adequate spacing of testing is necessary if we are to have a meaningful standard for the 

longer-term stability of a particular test method in a particular laboratory installation. 

We are also taking 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. .

Accuracy Qualification. We are proposing accuracy criteria for absolute fuel 

parameters that are similar to the criteria for sulfur in diesel fuel. Applicants for 

qualification would be required to select two commercially available gravimetric standard 

reference materials and then to 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 or ARV for each. How close to the ARV these averages must be is the 

stringency part, and we propose to use 0.75 times the precision criterion described above, 

 

441 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.

442 71 FR 16492(April 3, 2006).

443 See EPA-HQ-OAR-2005-0048-0002.
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which is the same value as the diesel rules. 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. We are proposing that for other parameter that might come to 

fall into the absolute category, 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.444

iii.How Would Laboratories Demonstrate The Precision and Accuracy of 

Methods for Measuring “Method-Defined” Parameters and Qualify the 

Methods for Use?

Operational Description. For method-defined parameters we are proposing the 

same operational description as that for absolute parameters. The operational description 

of a proposed test method must be very complete. We consider publication of a test 

method by a VCSB organization such as ASTM to meet this criterion. For non-VCSB 

test methods this description must meet very high standards for completeness and clarity. 

Since non-VCSB test methods have not been fully vetted by a VCSB, a non-VCSB test 

method would require additional information. In particular, the underlying scientific 

measurement principles must be thoroughly explained and the apparatus described well 

enough that a trained outsider could successfully implement the non-VCSB test method 

and replicate the applicant’s results.

Precision Qualification Specifics. We are proposing the same precision 

qualification criteria as absolute parameters. For those method-defined parameters with 

alternative test methods that have been identified by regulations, preference will be given 

to the least precise of the allowed test methods. For reference installations we propose 

the additional requirements that the instrument must be shown to be in statistical control, 

as provided for in ASTM D6299-10e1 (and the SQC procedures to be discussed below); 

and that the applicant must submit control charts showing a record of in-control operation 

for at least five months. While these requirements would likely result in a delay between 

instrument setup and the ability to qualify it as a reference installation, we believe that the 

delay is necessary to demonstrate the stability of these critically important installations. 

Considering the number of long-established installations of these designated test 

methods, EPA expects no lack of laboratories capable of meeting these standards and 

able to provide this service commercially to any party interested in qualifying a new 

installation of an alternative test method for a method-defined parameter. Table VI-6

 

444 It is important to understand that the numerical examples presented in the text are entirely hypothetical, 

since 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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sets out our proposed precision criteria for the various method-defined fuel parameters 

with no alternative test method. 

Olefins in Gasoline Criterion. The designated method for this parameter, ASTM 

D 1319-10, is also the less precise of the two methods currently allowed. As such, its 

repeatability statistics are proposed as the basis for precision qualification. Thus for a 

test fuel with olefins at, say, 9 volume percent, the repeatability is 0.972, and the 

underlying standard deviation is 0.972/2.77=0.351, and the precision criterion is 1.5 

times that, or 0.53 volume percent. A laboratory’s standard deviation for the 20 tests 

could not exceed that value and still qualify for precision.

Aromatics in Gasoline Criterion. We are proposing to use the repeatability

standard deviation for D1319-10 to set the precision criteria for aromatics in gasoline. 

(e.g., 1.3 volume percent for a fuel with 32 volume percent aromatics). The cut off point 

for the 20-test standard deviation using the test fuel would then be 0.70 volume percent. 

We note that D5769-10 is the current designated test method but that D1319-10 is still 

widely used. We also note that while not as precise as D5769-10, D1319-10 is the 

designated method for olefins, and has precision sufficiently close to that of the more 

modern designated method to make it still viable. 

Oxygen and Oxygenates in Gasoline Criterion. The two test methods allowed for 

oxygen are very close together in precision, at least for total oxygen content. The 

designated method, D5599-00(2010) is slightly less precise, leading us to propose that its 

repeatability be used to determine the criterion. So for a test gasoline with 3 mass 

percent total oxygen, the repeatability would be 0.083 mass percent and the criterion for 

precision in this example comes out to 0.045 mass percent.

Table VI-6 Method-Defined Precision Criterion for Fuel Parameters with no 

Alternatives to the Designated Test Method

Fuel Parameter Example of fuel parameter 

level for demonstrating 

precision 

Proposed Precision 

Criterion445

RVP in gasoline RVP sample of gasoline 

equals 6.8 psi

0.11 psi

Distillation in gasoline Gasoline sample with initial 

boiling point (IBP) of 20 °C 

and 90 percent evaporated 

(E90) temperature of 110 °C

IBP = 1.54 °C

E10 = 0.72 °C

E50 = 0.40 °C

E90 = 0.97 °C

FBP = 1.80 °C

Benzene in gasoline Gasoline sample containing 1 

volume percent benzene

0.02 volume percent benzene

 

445 Where maximum allowable standard deviation (SD) of 20 tests is less than or equal to 1.5 times the 

repeatability (r) of the designated test method divided by 2.77 (SD of 20 tests ≤ 1.5 X (r/2.77)).
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Aromatics in diesel fuel Diesel sample containing 35 

volume percent aromatics

0.70 volume percent

Accuracy Qualification. Test methods used to measure method-defined 

parameters can be grouped into three types: reference installations of designated methods 

intended for use in qualifying alternative methods; designated method installations 

intended for ordinary production measurements; and non-designated methods. Since 

these reference installations will be used to evaluate the accuracy of other test methods 

and to evaluate whether the need for the establishment of a correlation equation. We are 

proposing that such reference instruments must be shown to be near the middle of the 

distribution of the industry monthly inter-laboratory crosscheck program for at least five 

months prior to application.446 We are proposing that laboratories would specifically 

compute the difference between either 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 are proposing that the differences would then be standardized by

expressing it in robust standard deviation units. This standardized Inter-laboratory cross 

check (ILCC) differences would be put into a moving average with a span of, for 

example, five months. We are also proposing to set the standard such that the 

instrument's moving average would be within the central 50 percent of the distribution of 

participating designated method labs. Because a robust standard deviation is used by the 

ILCC program, this percentage will have to be approximate. 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. EPA requests comment on the nature and stringency of this 

proposed requirement. Specifically, we request comment as to whether this is a 

reasonable requirement that is likely to be met by instruments in the best qualified 

laboratories. Could the “middle 50 percent” requirement be further tightened without 

severely restricting the supply of potential reference installations? Are there 

computationally simpler ways to accomplish the general purpose of this requirement?

(1) Role of Voluntary Consensus Bodies in Qualifying Alternative Analytical Test 

Methods

In February 1996, Section 12(d) of Public Law 104-113, Congress passed the 

National Technology Transfer and Advancement Act of 1995” (NTTAA), in order to 

establish the policies of the existing OMB Circular A-119 in law.447 The purposes of 

Section 12(d) of Public Law 104-113 are: (1) To direct “federal agencies to focus upon 

 

446 An alternative to this measure can be to use the D6299-10e1 calculations. This would require statistical 

quality control (SQC) so that the instrument would have an acceptable quality of performance. This could 

reduce the burden of calculations and align this requirement better with the NTTAA.

447 See 142 Cong. Rec. H1264-1267 (daily ed. February 27, 1996) (statement Rep. Morella);142 Cong. Rec. 

S1078-1082 (daily ed. February 7, 1996)(statement Cong. Rockefeller); 141 Cong. Rec. H14333-34 (daily 

ed. December 12, 1995)(statements of Reps. Brown and Morella).
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increasing their use of [voluntary consensus] standards448 whenever possible,” thus 

reducing federal procurement and operating costs; and (2) to authorize the National 

Institute of Standards and Technology (NIST) as the “federal coordinator for government 

entities responsible for the development of technical standards and conformity

assessment activities,” thus eliminating “unnecessary duplication of conformity

assessment activities.”449 Section 21(d) of Public Law 104-113 also gives agencies the 

discretion to use other standards in lieu of voluntary consensus standards where use of the 

latter would be “inconsistent with applicable law or otherwise impractical.” However, in 

such cases, the head of an agency or department must send to OMB, through NIST, “an 

explanation of the reasons for using such standards.”

The final revision of Circular A-119 defines Voluntary Consensus Standards as 

“standards developed or adopted by voluntary consensus bodies, both domestic and 

international”, and defines VCSB as “domestic or international organizations which plan, 

develop, establish, or coordinate voluntary consensus standards using agreed-upon 

procedures and which possess the attributes of openness, balance of interest, due process, 

an appeals process, and consensus.” Finally, Circular A-119 indicates that consensus 

means “general agreement, but not necessarily unanimity, and includes a process for 

attempting to resolve objections by interested parties, as long as all comments have been 

fairly considered, each objector is advised of the disposition of his or her objection(s) and 

the reasons why, and the consensus body members are given an opportunity to change 

their votes after reviewing the comments.”450

The Agency believes that VCSBs can play a valuable role in developing statistical 

tools for analytical test methodology description and evaluation, developing and 

describing new analytical test methodologies and organizing test programs to evaluate 

methodologies and assist laboratories to maintain quality measurement systems.

EPA has frequently selected VCSB-developed methods as its designated methods 

for fuels programs. However, it has only adopted a particular version of each such 

method by incorporating it by reference in the Federal Register. In each case the Agency

was endorsing and adopting test methods that were completely known and available for 

examination, rather than the unknown result of some future VCSB action. To simply say

that any method approved by a VCSB is acceptable for all purposes, including 

compliance demonstrations would seem to invite such difficulties as: (1) multiple

methods for a parameter, developed by different VCSB’s and not correlated adequately 

with each other, or (2) methods that change over time (by publication of new versions, 

for example) in such a way that the definition of what is being measured changes and no 

longer corresponds to what was used in setting compliance to the environmental 

standard(s).

 

448 This use of the word “standards” refers to test methods, calibration materials, etc.

449 See Cong. Rec. H1262 (daily ed. February 27, 1996)(statements of Rep. Morella).

450 63 FR 8546 (February 19, 1998).
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(2) Use of Reference Materials in Qualifying and Maintaining Alternative Analytical 

Techniques

Depending on the qualification process chosen by the Agency, discussed in more 

detail below, the protocol proposed here for the qualification and maintenance of 

alternative test methods stops short of automatic acceptance of VCSB decisions and 

methods, but goes as far in that direction as we believe is consistent with the Agency’s 

mission of ensuring compliance with motor vehicle fuel programs. It gives some 

preference to VCSB-approved methods because of our greater confidence that such 

methods have been positively evaluated by a broad user community rather than by a 

narrower array of users. We are proposing e today to also make substantial use of 

VCSB-developed statistical protocols for comparing methods and for use by particular 

laboratories in keeping analytic methods under adequate statistical quality control.

We consider Reference materials to be samples of the type of material to be tested 

(gasoline or diesel fuel in this case) that are known or thought to have a particular 

concentration of the substance to be measured. Laboratories may use these materials to 

calibrate and evaluate the performance of measurement systems. EPA is proposing the 

following three types of reference materials that would be used in establishing and 

maintaining the accuracy of both designated and alternative analytical test methods: (1) 

gravimetric standards, (2) consensus-named fuels (gasoline or diesel fuel), and (3) 

locally-named standards.

Additionally, some combinations of parameters and test methods limit the 

availability of some kinds of reference materials. This complicates the task of developing 

a methodology for qualifying alternative test methods. EPA recognizes the technical 

complexity and the likelihood that new analytical testing methods may emerge. 

Therefore, the Agency is also proposing to offer substantial flexibility in the choice of 

standard reference materials and the manner of their use, so long as they ensure accuracy

and preserve the integrity of applicable fuel standards.

Gravimetric Reference Standards. Gravimetric standards are test materials made 

by adding a carefully measured 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. They do present certain practical problems in use. First, 

gravimetric reference materials cannot be made for all of the parameters under the RFG, 

CG and diesel fuel programs (e.g., distillation points and olefins). Second, there are 

“matrix effects.” As earlier explained, matrix effects are where components in real-world 

gasoline or diesel fuel other than the analyte of interest confuse the instrument and cause 

it to measure the analyte differently than it would when measuring the same 

concentration of the analyte in a gravimetric standard built in a matrix where the 

instrument is not sensitive. Matrix effects are problematic for certain analytical methods,

whose underlying scientific operating principles make the analytical method unable to 

utilize gravimetric standards for calibration when other types of materials (gasoline or 

diesel fuel) will have to be measured accurately. The approach taken in this proposal, 
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where the gravimetric standard reference materials would be used in establishing the 

accuracy of a reference implementation of the designated method, is an approach that 

should minimize matrix effect problems. This is because the designated methods were 

selected, among other criteria, for their relative freedom from matrix effects. Thus, EPA 

believes that such materials, offer the best tools for establishing the accuracy of analytical 

test methods. When feasible, EPA believes that gravimetric reference standard materials 

should form the basis for establishing accuracy through correlation with designated 

analytical test methods calibrated with gravimetric standards.

Consensus-named Fuels. These 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.

There are certain parameters that the Agency does not believe that gravimetric 

standard reference materials can be prepared. Aromatics are a class of numerous 

compounds that are produced by refinery processes in a mixture that is most likely

impossible to duplicate in the laboratory with any consistency for all fuel because not all 

refiners have the same configuration. For such parameters, it is therefore necessary to 

use consensus-named gasolines to control accuracy because they are the only reliable 

type of standard reference material that is available. The use of consensus-named 

gasolines may minimize matrix-related effects where they are used to establish the 

accuracy of different designated method implementations, though they may be less useful 

in evaluating alternative methods that have been adapted to measure a certain fuel matrix, 

but not sensitive enough to measure all fuel matrices the test method may encounter in 

use, otherwise known as “adaptive learning” technologies. The nominal concentrations 

in consensus-named gasolines can only be as accurate as the designated analytical test 

method used in the VCSB round robin study that named them. Consensus-named 

gasolines will also be costly and time-consuming to produce and will need to be 

periodically replaced (i.e., when the supply is exhausted or the shelf life expires) through 

either a new round robin study or some approach using overlapped testing of the old 

standard reference material with a new batch (which will not, of course, have exactly the 

same concentration of analytes). 

Locally Named Reference Materials. These materials are also sometimes referred 

to as quality control samples (e.g., octane testing reference fuel). These are gasoline or 

diesel fuels that usually come from the regular production of the facility. These reference 

materials 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. The fuels are then stored carefully by the lab to slow their 

deterioration. The advantage to these is that since a refinery may already have such fuels 

on site for octane or cetane testing purposes, these materials may be relatively

inexpensive. Another advantage is that, since a refiner would produce these fuels at the 

same site where the alternative method will be qualified, their use should minimize any

difficulties associated with matrix effects. These locally named reference fuels are not as 

accurate as the VCSB round robin process and are not assured by gravimetric standard 

reference material construction. Thus, a refiner could only use them for relating an 
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alternative method to a carefully calibrated installation of the designated method whose 

accuracy has been established and controlled by other means.

We request comment on the appropriateness of using the three types of standard 

reference materials for accuracy that have been discussed and on their applicability in the 

qualification process and statistical quality control process of analytical test methods.

(3) Qualification Criteria of Alternative Analytical Test Methods 

We are also proposing two options for refiners that wish to qualify an alternative 

test method as discussed in further detail in Sections VI.3.g.i and VI.3.g.ii of this 

proposal. For both of the proposed options the candidate test method must have precision 

at least equal to that of the designated analytical test method (though not defined in 

precisely the same way). And the alternative test method must be capable of correlation 

with the designated test method for the parameter such that the refiner may use the 

alternative test method results to produce predicted designated test method results that it 

can subsequently use in demonstrating compliance with the applicable fuel composition 

or performance standards. 

(4) Statistical Quality Control Program 

An important element of today’s proposed approach for the qualification of 

alternative analytical test methods is the description of a statistical quality control (SQC) 

program that may be applied to any analytical test method used in the regulatory

programs covered by this proposal. We are proposing to require a SQC program as 

described below. EPA’s objective with statistical quality control is not to impose a 

complete new system of quality control measures, but rather to adopt a subset of SQC 

procedures that are already widely in use. We anticipate that the measures we have 

selected would not require the generation of much additional data by the laboratories that 

elect to employ them and that the SQC program would improve the quality of 

measurement among those labs that adopt such measures.

e. Qualification Criteria for Designated Method Installations Used to Qualify 

Method-Defined Parameter Instruments.

Designated test method installations that will be used to qualify method-defined 

parameter instruments are reference installations. Since reference installations will be 

used to evaluate the accuracy of other alternative test methods and to establish correlation 

equations, EPA believes that these reference installations should be held to higher 

standards.

First, we are proposing that reference instruments meet precision qualification

requirements that are similar to the criteria set forth in the nonroad diesel sulfur rule. As 
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explained earlier, that rule imposed a maximum value for the standard deviation451 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. For those “method-defined” parameters from Table VI-1 above that do not 

currently have alternatives test methods the precision criteria is based on the fuel 

parameter’s designated test method. In each case the precision criterion is determined by 

(“r”/2.77) X 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.

Second, we are proposing that such reference instruments must be shown to be 

near the middle of the distribution of the industry monthly inter-laboratory crosscheck

(ILCC) program for at least the five months prior to application.452 We are also 

proposing 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. And then standardize this 

difference by expressing it in robust standard deviation units. These standardized interlaboratory cross check differences would be put into a moving average with a span of, for 

example, five months. We are proposing to set the standard such that the instrument's 

moving average would be within the central 50 percent of the distribution of participating 

designated method labs. Because a robust standard deviation is used by the ILCC 

program, this percentage will have to be approximate. 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 will serve as 

surrogates for the gravimetric standards that cannot be used in qualifying alternative 

methods for method-defined parameters. 

Finally, for reference installations we propose that the reference instrument must 

be shown to be in statistical control, as provided for in ASTM D6299-10e1 (and the SQC 

procedures to be discussed below); and that the applicant must maintain control charts 

showing a record of in-control operation for at least five months. While these 

requirements would likely impose a delay between instrument setup and the ability to 

qualify it as a reference installation, we believe that the delay is necessary to demonstrate 

the stability of these critically important installations. Considering the number of longestablished installations of these designated methods, EPA expects no lack of facilities 

capable of meeting these standards and able to provide this service commercially to any 

party interested in qualifying a new installation for a method-defined parameter. 

 

451 Where the standard deviation is estimated from a sample of the population (formula uses “N-1” in the 

denominator).

452 An alternative to this measure can be to use the ASTM D6299-10e1 calculations. This would require 

SQC so that the instrument would have an acceptable quality of performance. This could reduce the 

burden of calculations and align this requirement better with the NTTAA
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f. Qualification Criteria for Designated Test Method Installations that are 

“Method-Defined” Parameters Instruments and Not Used to Qualify Other 

“Method-Defined” Methods

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 

requirements453) in 40 CFR Part 80. Table VI-5 of this preamble lists the fuel parameters 

and their corresponding designated test methods.

We are proposing today that installations of designated methods must maintain 

records they meet statistical quality control requirements as detailed below in this 

preamble. Requiring all installations of all methods, including existing designated 

method installations, to implement statistical quality control, as we are proposing today, 

would likely suffice to homogenize and improve measurement quality in these alreadystable and standardized methods. 

g. Qualification Criteria for Method Defined Parameter Instruments Other Than 

Designated Test Methods

As discussed above, the Agency is also proposing to have two options for refiners 

to qualify an alternative test method that is a method-defined fuel parameter. The first 

option would allow for qualifying methods that have been sponsored and published by a 

VCSB, such as ASTM (the VCSB approach). The second way involves qualification for 

a laboratory that has developed its own analytical test method but has decided not to offer 

it for evaluation and establishment through a VCSB-based organizational process (the 

non-VCSB approach). Both options require the candidate method to have precision at 

least equal to that of the designated analytical test method (though not defined in 

precisely the same way). 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. The proposed criteria for both the VCSB and non-VCSB 

approaches to qualify method-defined instruments are discussed in further detail below.

i. Qualification Criteria for VCSB Method-Defined Parameter Test Methods

The first of these approaches to qualifying alternative methods applies only to 

methods that have been sponsored and published by a VCSB, such as ASTM. We are 

proposing that the VCSB must have fully described the analytical test method, so that it is 

replicable in different laboratories and understood by any technician. We would consider 

publication of a method by a VCSB organization such as ASTM to meet this criterion. 

 

453 See §§80.580, 80.584 and 80.585.
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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.454

We are also proposing that an 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 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 proposed 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.455 EPA is also proposing that VCSB method-defined test methods 

utilize ASTM D6708 to determine if a correlation equation is necessary.

ii. Qualification Criteria for non-VCSB Method-Defined Parameter Test 

Methods

The second way a candidate alternative method may qualify does not involve the 

process by which a VCSB evaluates and officially establish methods through publication. 

EPA is proposing that a candidate method that follows the non-VCSB-based route for 

qualification must be qualified independently by each analytical laboratory that wishes to 

adopt the method. This is because such a method has not been shown to be capable of 

accurately measuring the parameter in different laboratories and across a variety of fuel 

matrices. 

The following is a discussion of the qualification criteria for non-VCSB methoddefined parameter test methods. First, the Agency proposes to require a complete 

operational description of the non-VCSB test method, as described above in Section 

VI.3.d.iiand VI.3.d.iii of this preamble. 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.

 

454 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. The more detailed discussion of the two approaches that follows this 

introduction explores this problem.

455 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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Second, the Agency proposes that the candidate non-VCSB test method be tested 

on a range of fuels456 and by a qualified reference installation of the applicable 

designated test method.

Third, the Agency proposes 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 is proposing 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. It is possible a situation may arise where 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 D6708-08 statistical 

variability criteria). In this situation, the types of fuels on which qualification was 

achieved and for which the method 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 that was not this limited. The Agency believes that any 

restriction on the scope of fuels for which the method is to be qualified must be 

accompanied by a discussion of how the applicant plans to screen samples for conformity

to the scope.

Fifth, the Agency proposes that precision qualification be conducted in the form 

of cross-method reproducibility457 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.

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.

As described, this measure can reasonably be expected to fall between the 

published reproducibility (R) and repeatability (r) of the designated test method. Because 

qualified alternative test methods should be able to generally do as well as the designated 

test method Rcm be less than or equal to “R”. Since “R” is typically established when 

 

456 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.

457 Cross-method reproducibility is a quantitative expression of the random error associated with the 

difference between two results obtained by different operators using different apparatus and applying the 

two methods X and Y, respectively, each obtaining a single result on a identical test sample, when the 

methods have been assessed and an appropriate bias-correction has been applied. It is defined as the 95 

percent confidence limit for the difference between two such single and independent results.
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the test method is first developed, and laboratory experience with it is limited, the real 

reproducibility for a method long in service is likely to be smaller than “R.” Moreover, 

as mentioned above, Rcm is more like a site precision number, for a well-run installation, 

that must be smaller than “R” since the systematic component of the differences between 

the instruments has been adjusted out and the “within-method-interlaboratory” 

component of variance is not present. On the other end of the space between “r” and 

“R,” the published repeatability has far fewer sources of variability than any other 

measure of its kind, suggesting that the cut-point should be closer to “R” than to “r”. The 

proposed 70 percent fraction of published reproducibility was selected because there is 

some evidence to suggest that site precisions for various methods/parameters tend to 

average around that fraction of the same method’s published reproducibility. We are also 

requesting comment on the appropriate percentage of “R” that the “cross-method 

reproducibility” should be equal to or less than.

Sixth, the Agency proposes that the applicant demonstrate, through the use of 

ASTM D6708-08, whether a correlation to the designated test method is necessary. 

ASTM D6708-08 can also be used to determine whether the candidate method’s results 

are 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 are proposing the use of 

ASTM 6708-08 for corrections, if it is determined through the use of ASTM D6708-08 

that the candidate method requires such a correction to predict designated test method 

results. The Agency proposes that the correction would be applied to the candidate 

instruments output to obtain measurements results for regulatory purposes.

Finally, we are proposing 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 are proposing 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 the 

requirements for non-VCSB test method qualification have been satisfied. The Agency

believes this requirement would provide additional assurance that a non-VCSB test 

method is found to be adequate in use for compliance.

We seek comments on all aspects of today’s proposal. Additionally, the Agency is 

particularly interested in comments on the appropriateness of the qualification criteria for 

candidate method-defined parameter non-VCSB test methods.

h. Statistical Quality Control: How Can We Ensure that Test Methods Continue 

to Deliver Quality Measurement in Practice?

As discussed previously, an important element of today’s proposal is a statistical 

quality control program that may be applied to any analytical test method used in the 

regulatory programs covered by this proposal. Today, the Agency is proposing that every

laboratory using test instruments to measure fuel parameters must implement and 

maintain a basic SQC program in order to satisfy EPA’s reporting or recordkeeping 

requirements. We are proposing that every laboratory have a separate SQC program for 
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each instrument used to make measurements for reporting or recordkeeping purposes.458 

This is unlike the qualification criteria requirements, where only one of a set of 

essentially identical instruments implementing the same method in a laboratory must 

qualify.

We are proposing that implementation of a SQC program by a laboratory would 

be a defense in any subsequent enforcement actions where the measurements are in use. 

We are proposing to adopt a subset of SQC procedures that are already widely in use 

from ASTM D6299-10e1. We anticipate that the measures we are proposing 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 labs 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 are 

yielding 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 

proposed minimum specific SQC requirements for laboratories that measures absolute 

parameters, and both VCSB and non-VCSB methods used to measure method-defined 

parameters, are discussed in further detail below.

i. Statistical Quality Control for Absolute Parameters

We are proposing precision and accuracy SQC requirements for each instrument 

used to measure absolute parameters in the laboratory. We are proposing that every

instrument would test a quality control (“QC”) material459 either of: once per 20 

production tests or once per week and maintain both an “I” chart460 and an “MR” chart461. 

We are proposing that any violations of the control limit(s) would be investigated by 

laboratory personnel, corrective action taken as required, and records kept of the incident 

for a period of 5 years. We are also proposing to follow the procedures of ASTM D6299-

10e1for making transition from one batch of QC material to another. We are a also 

proposing the use of Annex A1.9, entitled “Q-Procedure”, of ASTM D6299-10e1 for 

validating new QC material. We are proposing that when QC material is soon-to-bedepleted, that a new batch of QC material is prepared and its value compared to the old 

QC material on a chart. 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 

 

458 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.

459 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.

460 See ASTM D6299-10e1, section 7 and Section A1.5.1 for chart construction and usage, including criteria 

for deciding upon corrective action.

461 See ASTM D6299-10e1, Section A1.5.2 for chart construction and usage. Any exceedance of the control 

limit should be investigated.
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“old” and “new” QC materials on its respective chart, and if no special-cause signals are 

noted, then the result for the new material would be considered valid.462

We are proposing to require that every instrument tests a commercially available 

gravimetric standard reference material (SRM) (“check standard” as defined in ASTM 

D6299-10e1) on a quarterly basis. The absolute difference between the mean of multiple 

back-to-back tests of the SRM and ARV of the SRM 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 are 

proposing that records of the SRM measurements and investigations into any

exceedances of these proposed criteria must be kept for a period of 5 years. Additionally, 

we are proposing to require laboratories to pre-treat and assess results from the check 

standard testing after at least 15 testing occasions,463 construct “MR” and “I” charts464

with control lines, and maintain control charts, logging, investigating, and correcting the 

underlying causes of any control limit violations as discussed in ASTM D6299-10e1. We 

are proposing that records of such incidents and the underlying control charts must be 

kept by the facility for a period of 5 years.

ii. Statistical Quality Control for VCSB-Approved Methods Used to Measure 

Method-Defined Parameters

We are proposing precision and accuracy SQC requirements for every instrument 

used in VCSB-approved methods to measure method-defined parameters in the 

laboratory. With regard to precision, we are proposing the same SQC for instruments 

used for absolute parameters. We are proposing that every instrument test a quality

control QC material465 once every 20 production tests or once per week whichever is 

more frequent. We are also proposing the maintenance of an “I” chart466 and a “MR” 

chart467. We are proposing that violations of the control limit(s) in these charts would be 

investigated, corrective action taken as required, and records kept of the incident for a 

period of 5 years. We are also proposing that laboratories follow the procedures of 

ASTM D6299-10e1 for making the transition from one batch of QC material to the next.

 

462 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.

463 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.

464 See ASTM D6299-10e1, Section 8.4 and appropriate Annex sections for chart construction and guidance.

465 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.

466 See ASTM D6299-10e1, section 7 and Section A1.5.1 for chart construction and usage, including criteria 

for deciding upon corrective action.

467 See ASTM D6299-10e1, Section A1.5.2 for chart construction and usage. Any exceedance of the control 

limit should be investigated.
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With regard to accuracy we are proposing that each laboratory perform a check 

standard468 for each instrument as defined in ASTM D6299-10e1 for each instrument on a 

quarterly basis. We propose that check standards for “method-defined” parameters must 

be ordinary fuels with levels of the parameter of interest close to either regulatory

standards or to the average level of use. We also propose that ARVs of such standards 

must be determined through consensus methods469 on designated method instruments. 

The absolute difference between the mean of multiple back-to-back tests of the SRM and 

ARV of the SRM greater than 0.75 times the published reproducibility of the test method 

must be investigated, appropriate action taken by laboratory personnel, and records kept 

of the incident and investigation. We are proposing that records of the SRM 

measurements and investigations into any exceedance of the criteria must be kept for a 

period of 5 years. Additionally, we are proposing that laboratories must pre-treat and 

assess results from the check standard testing after at least 15 testing occasions470, 

construct “MR” and “I” charts471 with control lines, and maintain control charts, logging, 

investigating, and correcting the underlying causes of any control limit violations as 

discussed in ASTM D6299-10e1. We are proposing that records of such incidents and the 

underlying control charts must be kept by the laboratory for a period of 5 years.

iii.Statistical Quality Control for Non-VCSB Methods Used To Measure 

Method-Defined Parameters

We are also proposing precision and accuracy SQC requirements for instruments

used in non-VCSB methods to measure method-defined parameters in the laboratory. 

We are proposing precision requirements for instruments used in these types of test 

methods that are the same as those proposed for absolute parameters. We are proposing 

that every instrument be tested on a quality control “QC” material472 once per 20 

production tests or once per week, whichever is more frequent. We are also proposing 

the maintenance of an “I” chart473 and a “MR” chart474. We are proposing that violations 

of the control limit(s) in these charts should be investigated, corrective action taken as 

required, and that records of the incident must be kept for a period of 5 years. We are

 

468 As defined in ASTM D6299-10e1, Section 3,2,3, and further discussed in Section 6.2. Optimum use of 

materials that are consensus-named by a number of laboratories may be possible only if these materials are 

distributed in sufficient quantity that they may be used as check standards after their consensus-determined 

ARV is known by all laboratories. As mentioned in the text, only measurements made on the designated 

method for the parameter in question may be used in determining the ARV for this purpose.

469 Following the guidelines of ASTM D6299-10e1, Section 6.2.2.

470 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.

471 See ASTM D6299-10e1, Section 8.4 and appropriate Annex sections for chart construction and guidance.

472 See ASTM D6299-10e1, paragraph 3.2.3 for a definition and Section 6.1 for guidance, selection, 

construction, handling, storage and use of quality control samples.

473 See ASTM D6299-10e1, section 7 and Section A1.5.1 for chart construction and usage, including criteria 

for deciding upon corrective action.

474 See ASTM D6299-10e1, Section A1.5.2 for chart construction and usage. Any exceedance of the control 

limit should be investigated.
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proposing that laboratories follow the procedures of ASTM D6299-10e1 for transitioning 

from one batch of QC material to the next.

The proposed accuracy requirement depends on whether the method-defined 

parameter test method has minimal matrix interferences or whether the method-defined 

parameter test method is highly sensitive to matrix composition. The Agency believes 

that non-VCSB test methods are expected to vary considerably to the extent that their 

results are sensitive to fuel characteristics other than the level of the analyte of interest. 

For methods judged by their operators to be relatively insensitive to such matrix effects, 

EPA believes that the same SQC accuracy approach used with VCSB-approved methods 

measuring “method-defined” parameters is appropriate. Where this is the case, a 

statement to this effect must be included in the application for qualification. Any

decision to abandon this approach to SQC accuracy must be reported to EPA along with 

the data and reasoning that led to the conclusion. 

For non-VCSB methods used to measure method-defined parameters that are 

highly sensitive to matrix composition, we are proposing the same accuracy requirements 

that must be maintained as for other methods for method-defined parameters, except that 

the check standards will consist of production fuels, representative of those production 

fuels routinely analyzed by the laboratory, that have been submitted to a reference 

installation of the designated test method. We are proposing that the designated test 

method measurements should be replicated and the average of these results used as the 

ARV for the check standard. Additionally, we are proposing that the laboratory

operating the alternative method is responsible for the qualification status and current 

stability of the reference method installation (for example, documentation on the identity

of the reference installation and its control status must be maintained on the premises of 

the laboratory that is using the alternative test method).

Also for non-VCSB methods, the Agency is proposing external checks on the 

accuracy of matrix-sensitive methods. Laboratories that have qualified such a method 

would be required to send a sample of each 20th production batch of gasoline or diesel 

fuel to EPA’s Ann Arbor laboratory, along with the lab’s measurement results using the 

alternative method (the result used to certify the batch). The EPA lab may return such a 

sample on a blind basis for a required reanalysis by the originating laboratory at any time 

up to two months from EPA’s receipt of the sample. This external control is an 

additional check on both the site precision of the alternative method and its accuracy. We 

request comments on all aspects of our proposal.

i. Agency Approval Options

We are proposing to require qualification of only non-VCSB test methods for fuel 

parameters. We are also seeking comment on whether we should require qualification of 

all test methods for fuel parameters. We are also proposing a requirement for regulated 

parties to identify the test method used for each compliance measurement as part of the 

applicable record keeping and reporting. The following section contains a discussion of 

our proposal 
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We believe that the proposed approach to performance-based qualification of test 

methods goes considerably beyond the minimum requirements of the NTTAA in 

providing flexibility of method choice, and accomplish performance-based qualification 

without compromising measurement quality. We also believe that the primary tools for 

achieving the latter objective are lab-specific qualification of method installations and a 

requirement for across-the-board SQC. While EPA would benefit from finalizing today’s 

proposal by no longer having to evaluate new alternative measurement methodologies, 

this benefit is not likely to offset the substantial and unpredictable resource costs 

involved in administering a qualification process and providing infrastructural support for 

laboratories’ SQC programs. 

i. Agency Approval of Only Non-VCSB Methods

We are proposing that only non-VCSB test methods for fuel parameters would 

need to be qualified. We are proposing to exclude designated test methods that have been 

in operation 6 months prior to finalizing this rule, as discussed below, as well as test 

methods that are developed by VCSBs, like ASTM International or the International 

Organization for Standards (ISO). A laboratory that has developed a test method but has 

decided not to offer it for evaluation and establishment through a VCSB-based 

organizational process would be required to qualify the test methods using the process 

discussed earlier.475 We are proposing that such test methods must be qualified 

independently by each analytical laboratory that wishes to adopt the test method. This is 

because such a test method has not been shown to be capable of accurately measuring the 

parameter in different laboratories and across a variety of fuel matrices. 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 one other laboratory, and its accuracy must be demonstrated by direct correlation 

to the designated analytical test method for the particular fuel parameter. 

We are proposing the following requirements for test methods that have been 

sponsored and published by a VCSB such as ASTM or ISO. 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. 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 

 

475 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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discussed, and must have published the information necessary to correlate the alternative 

test method to the designated test method.476

We are proposing a system of self-qualification for VCSB-based alternative test 

methods. Thus, we are also proposing that a VCSB-based candidate alternative test 

method need not be qualified separately in each laboratory that adopts it. This is because 

by the time a VCSB-based candidate alternative test method has been through the 

extensive development process typically required by a VCSB, the test method’s 

procedures will 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, 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. 

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 

parameter477 and for determining whether the alternative test method can be adequately 

correlated with the designated test method.478 

We also recognize that imposing this qualification requirement on existing test 

methods developed by a VCSB without adequate lead time may be problematic. We are 

thus proposing to give methods published and in operation when this proposal is 

published a grace period of one year from the effective date of a final rule before they 

meet these proposed requirements.

We are also proposing to exempt existing (i.e., in use for six months prior to 

publication of this proposal) installations of designated test methods that are methoddefined parameters from the qualification requirement. We presume these to be stable 

and capable methods in relatively experienced hands. Because they are already being 

used to certify fuels, requiring their qualification could be disruptive and burdensome to 

both their operators and to whoever manages the qualification process. 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 are also proposing to require record keeping and retention requirements for 

both VCSB alternative and non-VCSB test methods. Parties would need to maintain 

 

476 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. The more detailed discussion of the two approaches that follows this 

introduction explores this problem.

477 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.

478 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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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 are also seeking comment on whether the Agency should require qualification 

of all analytical test methods for the fuel parameters at 40 CFR 80. This would include 

each designated test method, all alternative test methods 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 recognize that imposing the qualification requirement on existing and 

operational installations of all methods without adequate lead time may be problematic. 

We are thus proposing to give such laboratories (i.e., those in operation when this 

proposal is published) a grace period of one year from the effective date of the final rule 

before they must have qualified if they wish to continue in operation. We believe 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.

4. Downstream Pentane Blending

The current regulations at 40 CFR 80.82 reduce the burden of compliance with 

EPA gasoline quality requirements for parties that blend butane into conventional 

gasoline, reformulated gasoline (RFG), or reformulated blendstock for oxygenate 

blending (RBOB) downstream of a crude oil refinery. Parties that conduct such butane 

blending are considered a refiner, however, they are not subject to sampling testing 

requirements that would otherwise apply to a refiner provided they use butane of known 

quality and meet certain other requirements. Butane blending is not allowed into RFG or 

RBOB from April 1 through September 30 or into any RFG or RBOB that is designated 

as VOC-controlled. Butane blenders must test to ensure that the volatility requirements 

of the final gasoline blend are met. Testing to demonstrate compliance with other 

gasoline compositional requirements is not required provided that the blender has 

documents from the supplier demonstrating the butane is “commercial grade”. 

Commercial grade butane is currently defined as butane for which test results 

demonstrate that it is 95% pure and has the following properties: sulfur <= 30 ppm, 

benzene <= 0.03 volume %, olefins <= 1.0 volume %, and aromatics <= 2.0 volume %. 

Documents from the supplier demonstrating the butane is “non-commercial grade” may

also be used to demonstrate compliance with gasoline quality requirements other than 

volatility provided the blender conducts a quality assurance program on the butane they

blend. Non-commercial grade butane is currently defined as follows: sulfur <= 30 ppm, 

benzene <= 0.03 volume %, olefins <= 10.0 volume %, and aromatics <= 2.0 volume %. 

Today’s action is proposing to amend these butane specifications to replace the current 

30 ppm sulfur cap with a 10 ppm cap consistent with today’s proposed 10 ppm refinery

average sulfur standard. 
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Butane blenders stated that broadening the downstream butane blending 

provisions to include pentane would help to increase the domestic supply of gasoline by

providing a market for the pentane fraction of natural gasoline liquids. A substantial 

increase in the production of natural gasoline liquids is occurring as a by-product of 

increased domestic natural gas and crude oil production in the U.S. Given the lower 

volatility of pentane compared to butane, a greater volume of such domestically-available 

feedstocks could be blended into gasoline downstream of the refinery while still 

maintaining the gasoline quality specifications including RVP. We request comment on 

whether the provisions for butane blending might also be applied to pentane blending, 

including the specifications for the fuel qualities noted above. Specific comment is 

requested on the potential vehicle emissions and operability effects from such pentane 

blending. To the extent that pentane blending might displace butane blending, there may

be some decrease in evaporative emissions due to pentane’s lower boiling point 

compared to butane. Therefore, we anticipate that allowing downstream blending of 

pentane would have a neutral or marginally beneficial effect on vehicle emissions. If we 

were to extend the downstream butane blending provisions to pentane, we also seek 

comment on whether any additional pentane quality specifications or blending 

requirements would be necessary to protect vehicle emissions and operability

performance. 

B. Engine, Vehicle and Equipment Programs 

We are proposing several technical amendments to existing regulatory

requirements for motor vehicles and other types of vehicles and engines. These changes 

are intended to align with the Tier 3 standards proposed in this rule and to make various 

adjustments and corrections to the regulations. We are also proposing to remove large 

portions of obsolete regulatory text and update cross references accordingly. We request 

comment on all these amendments. However, we are not requesting comment on the 

underlying regulatory requirements except as specifically described in this section.

1. Fuel Economy Labeling

EPA adopted updated fuel economy labeling requirements in 40 CFR part 600 on 

July 6, 2011.479 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 would disallow certification to half of the existing smog ratings. We 

are therefore proposing a new smog rating scale starting in model year 2018. 

Manufacturers choosing to transition to the Tier 3 NMOG+ NOX standards based on a 

percentage phase-in could continue to meet Tier 2 standards for the “phase-out” fraction 

of the fleet through model year 2020, but would 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 scale in model year 2018 to reflect the start of Tier 3 

program for the majority of vehicles. 

 

479 76 FR 39478 (July 6, 2011). 
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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.480 We propose to omit rankings 2 and 4, ranking the 

eight emission levels in order over the remaining ratings. Omitting ratings 2 and 4 helps 

convey the larger absolute differences in the g/mile standards between Bins 70 and 125 

and Bins 125 and 160. 

We also propose to adjust the scale again in model year 2025 so that, consistent 

with the fuel economy and greenhouse gas rating, 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. 

Using this approach, we would apply a smog rating of 8 for TZEVs and omit 9 from the 

smog ratings. We request comment on applying smog ratings to TZEV vehicles; in 

particular, we request comment on any appropriate differentiation of TZEV vehicles, 

such as assigning different smog ratings based on the particular SULEV exhaust emission 

standards or the allowance value for different all-electric range values.

We request comment on these and other alternative approaches to revising the 

specifications for the smog rating on the fuel economy label. We also request comment 

on whether one or more transition rating scales would be appropriate to gradually adjust 

the smog rating scale as the fleet average standards become more stringent. 

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 proposing to take 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 

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.

 

480 http://www.arb.ca.gov/regact/2012/zev2012/fro2rev.pdf
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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. The proposal includes removal of 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 proposing to streamline 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 proposing to copy the new paragraph 

into the section for the older model-year provisions, with descriptive language in place to 

say when the new provision applies. This consolidation would allow 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 vehicles’ emission control systems. 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”).481 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 

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 

 

481 58 FR 58382 ( November 1, 1993)
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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 proposing in this rule 

to entirely remove the cert short test standards and test procedures from 40 CFR part 86, 

subparts O and S, and to similarly remove 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 proposing to update 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, where we already specify all 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 would 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 the new test procedures, we are proposing to eliminate 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 are also proposing to 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.

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 that 

would 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 85, 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. This can better be accomplished with appropriate references to the 
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procedures in subpart B instead of repeating text. Relying on references to subpart B 

would eliminate many pages of unnecessary printing, but it would also make it easier for 

us to maintain a consistent set of requirements. Changing a provision in subpart B would 

automatically apply for evaporative testing of heavy-duty vehicles without making that 

duplicate change in subpart M. In addition, as noted in Section IV.C, we are proposing to 

allow manufacturers of these vehicles to rely on an engineering analysis instead of 

performing new tests. This would further reduce the need to have separate requirements 

spelled out for these vehicles. The revised regulations preserve provisions that are 

specific to heavy-duty vehicle testing. In particular, the heavy-duty procedure involves 

testing with a different driving schedule and wider speed tolerances, testing does not 

involve ethanol-blended test fuel, and exhaust emissions are not measured during the 

drive preceding the two-day diurnal emission test. 

In some cases, the current regulations in subparts B and M include differences in 

test provisions 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. Perhaps the most important of these include 

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 preconditioning. We are also restoring 

paragraphs §86.1235(b) through (i) related to dynamometer operating procedures, which 

were inadvertently removed in an earlier rulemaking. This leaner approach for vehicles 

above 14,000 lbs GVWR is also consistent with our proposed change to waive 

evaporative testing requirements for certifying these vehicles.

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 proposing to revise 

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 make room for 

the new LA-92 driving schedule described in Section IV.B for heavy-duty vehicles, and 
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also to allow for reference to m/s values as described above for light-duty vehicles, we 

are proposing to eliminate 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.

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 plan to update §1065.1010 with the latest versions of all the reference procedures 

and technical standards that we identify. 

In areas of the regulations other than part 1065, we intend 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 do not plan in this rulemaking to make broad or 

universal changes to these references.

One particular area of interest relates to rounding. As described in Section 

IV.F.3, we are proposing to define “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. The proposed 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. 

VII. What are the Cost Impacts of the Proposed Rule?

We have estimated the costs for both the proposed vehicle standards described in 

Section IV and the proposed 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 draft RIA.

Section VII.C provides a summary of total costs for the proposed vehicle and fuel 

programs together. We have also compared the proposed program costs to the projected 

emission reductions in Section VII.D and compared these cost-effectiveness estimates to 
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those for other programs. 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 proposed standards 

assuming gasoline sulfur levels were reduced to a 10 ppm average. These technologies 

were then combined into technology packages which reflected vehicle 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), 

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 would be able to comply with 

the Tier 3 standards which we are proposing 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 improve to shorten the time it takes for the 

catalyst to light-off.

 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.
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 Evaporative Emissions Controls: Improved evaporative emissions systems, 

including canister scrubbers, more permeation-resistant materials, and 

improved system integration.

As stated above, we have developed our costs with respect to a given vehicle type 

and the type of engine with which it is equipped. Although the cost of achieving the 

proposed Tier 3 standards will increase with the size of the vehicle and the displacement 

of the engine, we have concluded that the cost for each engine type is independent of the 

type of vehicle in which it is equipped. For example, we estimate that the cost of catalyst 

loading for an in-line 4-cylinder (I4) engine will be the same whether the engine is in a 

car or a truck. 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 $199 (2010$) 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 applications 

will require this technology, while 75 percent of the V8 applications will require it. 

Table VII-1 below shows our estimate of the cost of each of the emission control 

technologies for the gasoline vehicles affected by this proposed 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 2010 dollars, are applicable for the 2017 MY 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 draft RIA.)

Table VII-1 2017MY Technology Costs by Gasoline Engine Type (2010$)

Technology

Gasoline Engine Typea

I4 V6 V8 HDc V8

Catalyst Loading $72 $95 $119 $60

Optimized Close-coupled 

Catalyst

$24 $48 $72 $72

Optimized Thermal 

Management

$36 $36 $36 $36

Secondary Air Injection N/Rb$119 $119 N/R

Engine Calibration $2 $2 $2 $2

Hydrocarbon Adsorber N/R N/R $201 N/R

Evaporative Emissions 

Controls

$20 $20 $20 $20

a

I4 – In-line 4-cylinder, V6: 6-cylinder, V8: 8-cylinder

b N/R – Not Required

c Heavy-duty
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Table VII-2 Technology Application Rates for Gasoline Vehicles

Technology Technology Application Rate by Vehicle Type

I4 LDV V6 LDV V8 LDV I4 LDT V6 LDT V8 LDT HD V8

Catalyst 

Loading

100% 100% 100% 100% 100% 100% 100%

Optimized 

Closecoupled 

Catalyst

50% 60% 75% 50% 60% 75% 0%

Optimized 

Thermal 

Management

25% 25% 25% 25% 25% 25% 25%

Secondary

Air Injection

N/R 25% 75% 0% 25% 75% N/R

Engine 

Calibration

100% 100% 100% 100% 100% 100% 100%

Hydrocarbon 

Adsorber

N/R N/R 15% 0% 0% 15% N/R

Evaporative 

Emissions 

Controls

100% 100% 100% 100% 100% 100% 100%

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 LDT4 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 LDT4s, as in many cases identical 

powertrains and chassis exist between the LDT4 and MDPV platforms.

We also expect that manufacturers will 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 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.
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Table VII-3 2017MY Technology Costs and Application Rates for Diesel Engines 

(2010$)

Technology

Diesel Engine 

Costs

(all types)

Light-duty and 

Heavy-duty

Application 

Rate

Optimized Thermal Management $36 25%

Engine Calibration $2 100%

SCR Optimization $60 100%

Costs have also been estimated for HDVs between 8,501 and 14,000 lbs GVWR. 

Vehicles in this range are often referred to as Class 2b (8,5001-10,000 lbs) and Class 3 

(10,001-14,000 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 may be found in Table VII-1, Table VII-2, and 

Table VII-3 above. 

We have also considered the impacts of manufacturer learning 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. The observed phenomenon in the economic literature which 

supports manufacturer learning cost reductions are based on reductions in costs as 

production volumes increase with the highest absolute cost reduction occurring with the 

first doubling of production. For additional information on technology learning refer to 

Chapter 2 of the draft RIA. Learning impacts have been considered on all of the

technologies expected to be used with the assumption that all technologies are on the flat 

portion of the learning curve. We did not consider any of the technologies to be on the 

steep portion of the learning curve because none are being used for the first time in the 

2017-2025 timeframe. 

Finally, we have prepared our cost estimates for meeting the Tier 3 standards 

using a baseline of Tier 2 Bin 5 technologies for all LDVs, LDTs, and MDPVs. The 

baseline fleet used for these cost estimates is the MY 2016 light-duty fleet predicted by 

the 2012-2016 GHG Rule. The 2012 GHG Rule provides us with the clearest picture of 

what the light-duty fleet may look like in MY 2017. Additional details on how the 2017 

MY fleet (i.e., the reference case fleet for this proposal) was developed can be found in 

Chapter 2 of the draft RIA. In short, the 2012-2016 GHG final rule is expected to result 

in considerable downsize of engines along with turbocharging to maintain performance. 

Since engines are expected to be downsized, the estimated Tier 3 costs are impacted since 

smaller engines are expected to incur lower costs as shown in Table VII-1.

Since GHG standards for the 2017-2025 fleet have just recently been finalized, 

we were not able to reflect their potential impacts on the baseline fleet in this proposal. 

We do not expect the MYs 2017-2025 GHG standards will change the technologies that 
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we project will be used to comply with the proposed Tier 3 standards. However, some of 

the changes to the vehicle fleet expected to result from the MYs 2017-2025 GHG 

standards, such as a greater penetration of downsized engines, could lower the cost of 

complying with Tier 3 standards. The final Tier 3 rule will include the changes to the 

fleet associated with the GHG standards and the resulting impacts on cost. 

The evaporative emissions standards that we are proposing for LDVs, LDTs, 

MDPVs, and HDVs are feasible with relatively small cost impacts. We estimate the cost 

of system improvements, including indirect cost markups, to be about $20 (2010$) per 

vehicle, for all car 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 low-permeation 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 draft RIA. We request comment on this detailed analysis. In 

particular, we request comment on the completeness of the list of emission control 

components needed for meeting the Tier 3 evaporative emission standards, especially 

regarding purge and purge-assist technologies.

We have used the individual technology costs discussed briefly here and in more 

detail in Chapter 2 of the draft 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 project sales estimates for the 

years 2017 and later. The projected sales estimates used, as noted earlier, represent the 

reference case fleet mix rather than today’s fleet mix. That fleet mix is discussed in more 

detail in Chapter 2 of the draft RIA. With these total annual costs, we then determined 

the sales weighted average cost increase for all passenger cars, light trucks and heavyduty vehicles. Table VII-4 below provides our estimates of the incremental cost per 

vehicle (both light-duty and class 2b and 3 vehicles) 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 rates. As stated above, a large 

portion of the cost is incurred in the initial model years due to the adoption of the LEV III 

declining fleet average. Costs then continue to rise as the percentage of vehicles 

complying with the proposed standards increases through the 2025 MY. 

We have estimated costs consistent with the fact that manufacturers would be 

required to start the phase-in of Tier 3 standards in MY 2017 for vehicles under 6,000 lbs 

GVWR and MY 2018 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 would be 

required to move from a Tier 2 Bin 5 fleet average in the 2017 MY (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. It is also important to 

note that while we are aligned with CARB on the individual cost of each technology and 

their application rates, our costs are different from California’s LEV III costs due to the 

fact that the California fleet is currently meeting slightly more stringent standards than 

the federal fleet. Thus, the incremental cost for California is less. Finally, manufacturers 

would have the opportunity in 2015 and 2016 MY to earn Tier 3 credits by producing a 
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fleet that is cleaner than the current Tier 2 requirements. While we expect that most 

manufacturers would 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 Costs by Model Year

Model Year 2017 2018 2019 2020 2021 2022 2023 2024 2025

$/car $78 $87 $92 $99 $103 $112 $111 $115 $118

$/truck $0 $105 $114 $127 $136 $150 $151 $159 $165

Light-duty Combined $50 $94 $100 $109 $115 $125 $124 $130 $134

$/2b (Truck or Van) $0 $43 $50 $58 $64 $73 $69 $68 $66

$/3 (Truck or Van) $0 $38 $46 $55 $63 $73 $69 $68 $66

Note: Costs shown include costs for the proposed Tier 3 standards on vehicles sold in all 

states except California.

Total annual costs are shown below in Table VII-5. This table includes all costs 

associated with the proposed Tier 3 vehicle standards, i.e., both exhaust and evaporative 

emission standards, for both light-duty vehicles and 2b and 3 heavy-duty pickup trucks 

and vans. Also included are facility related costs associated with the proposed 

requirements to conduct more PM testing on gasoline vehicles. (Additional detail 

regarding the PM facility costs are described below.) We show the facility costs in the 

year 2016 even though the program does not begin until 2017. These costs represent the 

construction cost that would have to be done in advance of the first year of the standards 

in preparation for the testing efforts that would be required. The annual costs shown for 

each cost element are undiscounted annual costs for the years 2016 through 2025, then 

2030, 2040 and 2050. The present values shown are for the years 2012-2050 at both the 

3 percent and 7 percent discount rates. We have shown present values in 2012 for 

comparison to EPA’s 2012-2016 GHG final rule and the recent MYs 2017-2025 GHG 

rule and to more closely estimate the costs of the program today.

Table VII-5 Undiscounted Annual Costs & Costs of the Vehicle Program 

Discounted back to 2012 at 3% and 7% Discount Rates (Millions of 2010 Dollars)

Exhaust Evap Facilities

Light-duty 2b/3 All Light-duty 2b/3 All All Total
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Year

2016 $0 $0 $0 $0 $0 $0 $22.5 $

2017 $634 $0 $634 $71.4 $0 $71.4 $3.75 $

2018 $1,150 $23.1 $1,170 $167 $3.86 $171 $3.75 $1

2019 $1,240 $28.6 $1,270 $159 $3.76 $162 $3.75 $1

2020 $1,350 $34.2 $1,380 $216 $5.22 $221 $3.75 $1

2021 $1,470 $40.0 $1,510 $208 $5.09 $213 $3.75 $1

2022 $1,580 $46.5 $1,630 $264 $6.52 $271 $3.75 $1

2023 $1,610 $44.8 $1,660 $253 $6.27 $259 $3.75 $1

2024 $1,720 $44.8 $1,770 $257 $6.38 $263 $3.75 $2

2025 $1,830 $44.9 $1,870 $246 $6.12 $253 $3.75 $2

2030 $1,750 $46.5 $1,790 $246 $6.74 $253 $3.75 $2

2040 $1,750 $51.9 $1,800 $246 $7.52 $254 $3.75 $2

2050 $1,750 $58.6 $1,810 $246 $8.49 $255 $3.75 $2

NPV, 

3% $29,900 $814 $30,700 $4,250 $116 $4,360 $89.1 $35

NPV, 

7% $14,700 $384 $15,100 $2,090 $55.0 $2,150 $52.2 $17

Note: Costs shown include costs for the proposed Tier 3 standards on vehicles sold in all 

states except California.

In addition to considering the costs associated with improving the emission 

control systems on vehicles, we also expect that manufacturers may need to improve their 

capability to measure PM at the levels we are proposing. For additional information on 

the test procedure changes we are proposing, reference Chapter IV.F.

We have used two sources of information to determine the appropriate costs for 

upgrading test facilities for PM measurement. The first was EPA’s own cost to upgrade 

its PM measurement equipment; the second was information provided by vehicle 

manufacturers. The cost estimates ranged from $250,000 to $500,000 per PM test site.

 We recognize that the number of sites that a manufacturer would require is 

dependent on the number of vehicle models it expects to develop and certify in a given 

model year. As stated in Section IV.A, we have limited the number of certifications 

required per model year to 25 percent of the represented durability groups, thereby 

potentially reducing the number of test sites that require upgrade. We believe that 

manufacturers with annual sales of one million units or less would require two facility

upgrades at an average cost of $375,000. For manufacturers with greater than one 

million units per year annual sales we believe that four facility upgrades may be required 

to meet the Tier 3 requirements. In addition to facility upgrades some manufacturers may

require an additional employee for PM weigh room operation and/or PM data 

management. Therefore we have added the cost of 1 additional full time employee for all 

manufacturers. Our estimated costs for each manufacturer are show below in Table 

VII-6. 
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Table VII-6 PM Facility Costs (2010 dollars)

Annual 

Volume

# of PM Sites 

to be upgraded Cost per site

Total Facility 

Cost

(one-time, 

upfront cost)

Additional FTE

(annual, 

ongoing cost)

≤1 million 2 $375,000 $750,000 1 @ $150,000 

> 1 million 4 $1,500,000 per year

Total $22,500,000 $3,750,000

a

FTE – Full Time Employee

B. Estimated Costs of the Fuel Program

1. Overview

The sulfur control program we are proposing today 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 proposed sulfur control program 

requires refiners and importers to reduce their gasoline sulfur levels on average down to 

10ppm. The ABT provisions being proposed along with the 10-ppm average sulfur 

control standard would allow refiners that reduce their gasoline sulfur levels below 10 

ppm to earn credits and transfer those credits to other refiners who would find it more 

expensive to reduce their sulfur levels down to the average standard. The ABT program 

would allow refiners to optimize their investments, which we believe would result in 

achieving the average sulfur control standard nationwide at lower costs. We are also 

proposing to either maintain the current 80-ppm sulfur cap at the refinery gate, or to 

lower it only as far as 50 ppm. We have modeled the impacts of the 80-ppm cap, but 

believe that the results for a 50-ppm cap would be comparable due to the limits on credits 

resulting from the 10-ppm average. We estimate that the national average refinery costs 

incurred to comply with the fully phased-in Tier 3 sulfur control program with ABT 

program would be 0.89 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 draft RIA. We request comment on all aspects 

of the methodology described in Chapter 5 of the draft RIA used for estimating the cost 

of the program using the refinery-by-refinery cost model. In particular, we request 

comment on: the methodology for estimating the sulfur content of the FCC naphtha; how 

FCC naphtha sulfur levels are impacted by both an FCC pretreater and an FCC unit; to 

what extent desulfurization costs for complying with Tier 3 vary due to the sulfur level 

entering the existing FCC postreaters installed for Tier 2; the estimated level of 

hydrotreating of light straight run (LSR) naphtha and natural gas liquids (NGL) occurring 

today; the level of hydrotreating of LSR and NGLs expected to occur under this program

and the magnitude of permitting-related costs in comparison to the overall project costs.
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2. Methodology

a. Overview of the Sulfur Program Cost Methodology

The basic methodology we used to estimate the cost of sulfur control for the 

proposed 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 proposed sulfur control program. We aggregated the 

individual refinery costs to develop a national average cost estimate for the proposed 

sulfur control program. Based on the flexibilities offered by the ABT program, refiners 

are expected to come very close to achieving the 10-ppm sulfur standard on average. 

Linear Programming Cost Model 

We considered performing our cost assessments using a linear programming (LP) 

cost model. LP cost models are based on a set of complex mathematical representations 

of refineries which, for national analyses, are usually conducted on a regional basis. This 

type of refining cost model has been used by the government and the refining industry for 

many years for estimating the cost and other implications of changes to fuel quality. 

The design of LP models lends itself to modeling situations where every refinery

in a region is expected to use the same control strategy and/or has the same process 

capabilities. As we began to develop a gasoline sulfur control program with an ABT 

program, it became clear that LP modeling was not well suited for evaluating such a 

program. Because refineries have different equipment, process different crude oils and 

produce different products, refiners will choose different technologies and run those 

technologies differently for controlling gasoline sulfur. In addition, because of the 

flexibility afforded by the nationwide ABT program, we initiated development of a more 

appropriate refinery-by-refinery cost model, as described below. However, the LP model 

remained important for providing many of the inputs into the refinery-by-refinery cost 

model developed for this rulemaking. 

b. Refinery-by-Refinery Cost Model

In contrast to LP models, 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 on” not impacting 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, built off the model 

developed for the MSAT2 rulemaking by Mathpro, specifically to evaluate the costs and 

other impacts of the proposed sulfur control program.
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Our refinery-by-refinery sulfur cost model incorporates the capacities of all the 

major units in each refinery in the country, as reported by the Energy Information 

Administration and in the Oil and Gas Journal. Regarding operational information, we 

know less about how specific refineries use the various units to produce gasoline and 

about such factors as octane and hydrogen costs for individual refineries. We used 

previous LP modeling work as the basis for estimating these factors on a regional basis, 

and we applied the average regional result to each refinery in that region (Petroleum 

Administration for Defense District; PADD). We compared the gasoline volumes 

estimated by the model for each individual refinery to the 2009 gasoline volumes from 

the RFG data base, which was the most recent year for which data was available, and we 

were satisfied with the model’s volumetric estimates.482

Refinery-by-refinery cost models have been used in the past by both EPA and the 

oil industry for such programs as the MSAT2 gasoline benzene control, highway and 

nonroad diesel fuel sulfur standards, and 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 better assessment 

of the overall market impacts than the LP model and of the variation of impacts across 

the refineries. For this refinery-by-refinery sulfur cost model, we conducted a peer 

review process, and have received some comments on the design of our model. These 

comments are contained in the peer review reports placed in the docket. We intend on 

addressing the peer review comments, as well as any public comments that we receive on 

our cost analysis for the proposal, when we conduct the cost analysis for the final rule.483 

The oil industry has also conducted a similar analysis using a refinery-by-refinery cost 

model, and we discuss the results of their analysis at the end of this chapter. 

The refinery unit responsible for the greatest contribution of sulfur to gasoline is 

the fluidized catalytic cracker unit (FCC). The FCC processes a very heavy feedstock 

which contains high levels of sulfur. 484 When the FCC cracks this heavy, sour feedstock, 

 

482 Our refinery-by-refinery analysis is better able to model the impacts of gasoline sulfur control than the 

refinery LP, yet, it is still limited by the lack of specific information on each refinery. Despite our 

commitment to accurately model the baseline operations of each refinery, we recognize that without 

detailed refinery-specific operations information at our disposal, actual individual refinery changes will 

vary from our predictions. Particular refineries may choose a different sulfur control path than that 

estimated by our analysis for a number of reasons, including differences in the baseline and our lack of 

knowledge for investment and ABT program use preferences for each refiner. We believe, though, that 

overall our refinery cost model captures the strategies and costs for complying with the sulfur control 

program.

483 Our review of most of the suggested changes recommended by the peer reviewers suggested that there 

would be little to no change in our desulfurization cost estimate (some of the changes would increase the 

estimated costs, while others would reduce the estimated costs). Also, we anticipate making other 

improvements to the cost analysis conducted for the final rule, which would necessitate a second round of 

peer review. 

484 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.
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a portion of the sulfur in the feed to the FCC ends up in the FCC naphtha, an important 

gasoline blendstock stream.485 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 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 Axxens Prime G+, 

Exxon-Mobil Scanfining, CDTech’s CDHydro and CDHDS, Phillips S-Zorb and UOP’s 

ISAL (UOP now offers a postreating technology named Selectfining). Despite the much 

lower sulfur contribution to the gasoline pool by the FCC after complying with Tier 2, the 

vendors which supplied sulfur control technology for complying with 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 that we used 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 educate ourselves of what would be involved to achieve a 10-ppm 

sulfur standard using postreating. 

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. 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 expensive for the amount of sulfur reduction 

obtained, the ABT analysis we conducted avoided many of these types of investments. 

Instead refineries with both pre- and postreaters today are quite able to achieve further 

gasoline sulfur reductions less than 10 ppm at a relatively low incremental cost and 

selling the credits to those refineries who would otherwise be faced with grassroots FCC 

postreater investments.

In addition to addressing the sulfur in the FCC naphtha, we believe that some 

refineries may need to reduce the sulfur in at least a couple of other gasoline blendstocks 

to ensure that it would be able to comply with a 10-ppm sulfur standard. One such 

gasoline blendstock is 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. However, some refineries don’t have isomerization units and probably do not 

hydrotreat the LSR. If LSR is not hydrotreated, we estimate that LSR could contain 

anywhere between 25 to 500 ppm sulfur. We believe that refiners that do not currently 

desulfurize their LSR could do so by either feeding it to their FCC postreater or their 

naphtha hydrotreater (the hydrotreater which desulfurizes the feed to the isomerization 

 

485 On average, the fluidized catalytic cracker supplies about 35 percent of a refiner’s gasoline output.
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and reformer units). Because this stream does not contain any olefins, it is an easy stream 

to hydrotreat and actually improves the hydrotreating conditions within the FCC naphtha 

hydrotreater. The second stream that may have to be hydrotreated is butane. Butane is 

removed from the incoming crude oil and FCC naphtha and some of it is blended back 

into gasoline in the summertime to bring the gasoline pool up to the RVP limit. 

However, much of the butane is transported to storage for subsequent blending into the 

wintertime gasoline pool. We estimate that butane can range from 1 ppm to 140 ppm 

sulfur, but the typical sulfur level for butane is likely around 10 ppm. Because butane 

can be high in sulfur, we project that some refiners may add relatively inexpensive 

caustic extraction processes which can remove the types of sulfur present in the butane 

pool. However, addressing butane sulfur may only be necessary for those refineries that 

are reducing their gasoline sulfur levels down to 5 ppm to generate credits for sale to 

refiners seeking to purchase credits. 

The nationwide ABT program is intended to optimize sulfur reduction by

allowing each refinery to individually choose the most cost-effective means of complying 

with the 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. 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. 

3. Summary of Costs without ABT Program

a. Nationwide Costs of the Proposed Sulfur Control Program 

We used a refinery-by-refinery cost model to estimate the costs of the sulfur 

control program being proposed today. 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 light straight 

run naphtha, in the case where we estimate that the light straight run naphtha is not being 

desulfurized today. 

Based on the results of our cost analysis, we estimate that for each refinery to get 

to a 10-ppm average level, (without the benefit of trading) the proposed sulfur control 

program would cost 0.97 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 2010 dollars. Refiners would be expected to make $2,527 million in capital 

investments to achieve this sulfur reduction. 
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We also estimated annual aggregate costs, including the amortized capital costs, 

associated with the new fuel standard. When the 10-ppm gasoline sulfur standard would 

take effect in 2017, we estimate that the sulfur standard would cost $580 million per year.

b. Distribution of Refinery Costs

The sulfur reductions estimated by the cost model and associated costs vary 

significantly refinery-by-refinery. Figure VII-1 summarizes the estimated per-gallon 

costs for complying with the sulfur control standard if no ABT program were 

implemented. 
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0

5

10

15

20

25

30

35

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45

50

0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 6.00 6.50

N

u

m

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eries

cents/gallon

Figure VII-1 Projected Refinery-by-Refinery Sulfur Control Costs for the Proposed 

Sulfur Control Program Assuming No ABT Program
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Figure VII-1 shows that the sulfur control costs would vary from no cost to almost 

6.5 cents per gallon. Some refineries have no FCC unit and thus, their gasoline is 

naturally low in sulfur and these refineries will not reduce their gasoline sulfur levels and 

not incur a sulfur control cost. 

4. Summary of Costs with ABT Program

The estimated costs described in Section VII.B.3 above assume that every

individual refinery must achieve the proposed 10-ppm sulfur standard on an annual 

average basis. However, as described in Section V.A.4, we are also proposing 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 proposed 

ABT program, refineries that can reduce sulfur below 10 ppm at a relatively low cost can 

generate credits which can then be obtained by refiners for whom the cost of attaining the 

10-ppm sulfur standard would be relatively high. The net effect of this credit trading 

would be to reduce the overall cost of the program.

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.

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 (there refineries don’t have FCC units). All such refineries were 

assumed to generate credits for the increment between 10 ppm and their current sulfur 

level.

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).

To optimize the nationwide average costs under an ABT program, we determined 

the credit price at which the total number of credits generated was equal to the total 

number of credits consumed. For an idealized scenario in which every refinery has the 

opportunity to make credit trades with every other refinery in the nation, we determined 
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that more than 60 percent of refineries would be involved in either generating or 

consuming credits. The nationwide average cost of compliance with the 10-ppm sulfur 

standard would be reduced from 0.97 cents per gallon to 0.79 cents per gallon. 

Such perfect nationwide trading, however, is not realistic. Under Tier 2 today, a 

significant fraction of Tier 2 sulfur credits are bought and sold within companies, but 

there is still a considerable amount of inter-company trading occurring. Under Tier 3, it 

would be more difficult to generate credits, and also more difficult to make up for 

deficits, consequently, we also investigated how more limited credit trading might affect 

the average cost of compliance with the 10-ppm sulfur standard. For instance, to address 

unplanned equipment downtime or other circumstances that could make future 

compliance more difficult, individual companies might decide to bank credits for their 

own use, declining to make credits that they generate at one of their facilities available to 

other companies. To evaluate such a scenario, we modeled a situation wherein credit 

trading would only occur within companies that own more than one refinery. Of the 21 

refining companies in this position, we estimated that credit generation and use would 

reduce compliance costs at six of them, with 18 refineries generating credits and 8 

consuming credits. Under this scenario, total capital costs would be $2,203 million and 

the nationwide average cost of compliance with the 10-ppm sulfur standard would be 

0.89 cents per gallon. We have chosen to utilize the costs from this intra-company

trading analysis for the proposal. However, in reality, we expect that some intercompany credit transfers would still occur due to the financial incentive the highest cost 

refineries would provide. To the extent that some inter-company credit transfers do 

occur, our cost estimates can be viewed as somewhat conservative. 

A summary of the ABT results assuming nationwide credit transfers and intracompany credit transfers (costs used in the proposal) is shown in Table VII-7.

Table VII-7 Impacts of Nationwide ABT Program

No ABT ABT with intracompany credit 

transfers

(proposed rule costs)

ABT with

nationwide credit 

transfers

Average fuel cost (¢/gal) 0.97 0.89 0.79

Total capital cost 

($million)

2,527 2,203 1,760

Number of refineries that 

generate credits

0 18 46

Number of refineries that 

consume credits

0 8 25

Number of refineries that 

neither generate nor 

consume credits

111 85 40

The cost information available for this NPRM was limited to the costs of reducing 

sulfur to either 10 ppm or 5 ppm, and thus we were not able to estimate refinery-specific 
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costs of reducing sulfur to other levels. As a result, our ABT modeling could not account 

for scenarios in which a refinery makes some capital investments to lower sulfur to some 

interim level, such as 20 ppm, and then purchases credits in order to demonstrate 

compliance with the 10-ppm standard. Our ABT analysis also could not account for 

credit generation at sulfur levels other than 5 ppm. Our ABT analysis, then, most likely

underestimates the cost savings that could occur due to ABT since the greatest 

efficiencies are achieved when every refinery has the option of using any combination of 

capital investments and credits generation or use. For the final rule, we may investigate 

methods for expanding our ABT analysis to examine these types of scenarios.

a. Distribution of Refinery Costs

The sulfur reductions estimated by the cost model and associated costs vary 

significantly refinery-by-refinery. Figure VII-2 summarizes the estimated per-gallon 

costs for complying with the sulfur control standard under an ABT program with intracompany credit transfers. 
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0

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-0.5 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5

Num

b

er ofrefineries

cents/gallon

Figure VII-2 Projected Refinery-by-Refinery Sulfur Control Costs for the Proposed 

Sulfur Control Program with ABT and Intra-Company Credit Transfers
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While the distribution of costs shifts slightly under an ABT program with intracompany trading in comparison to no ABT program, Figure VII-2 shows that the sulfur 

control costs would continue to vary from no cost to nearly 6.5 cents per gallon. 

b. Distribution of Refinery Sulfur Levels

We estimate that 85 out of 111 refineries would meet the 10-ppm sulfur standard 

without the use of credits under the intra-company trading scenario. As a result, only 

about 5 percent of gasoline would continue to have an annual average sulfur level above 

10 ppm. These refineries tend to be smaller than average. The distribution of sulfur 

levels under this scenario is shown in Figure VII-3.
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0

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100

5 10 12.5 15 17.5 20 22.5 25 27.5 30 32.5 35 37.5 40 42.5

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eries

Sulfur (ppm)

Figure VII-3 Projected Refinery-by-Refinery Sulfur Levels for the Proposed Sulfur 

Control Program with ABT and Intra-Company Credit Transfers
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5. Other Cost Estimates

Three other cost studies were recently 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). 486 ICCT retained Mathpro for this analysis. ICCT had 

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. 487 

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. 

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 proposed 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. 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 sets the 

gasoline price in the gasoline market today. 

 

486 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.

487 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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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

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 0.89 c/gal cost with an ABT program that assumes intercompany trading 

of credits, and higher than our 0.97 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. 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 $1875/bbl/day when the offsite costs are added on. Thus, the 

API capital costs are about 3 1⁄2 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 
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Haverly refinery cost model that we use,488 the API capital costs are almost two times 

higher. 

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. 

When API presented the costs, they stated that their grassroots capital costs were based 

on an actual installation for the Tier 2 program. This could be one 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 

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. Were we to adjust the 

API study capital costs, the projected costs would fall right in line with the other studies.

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 

 

488 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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standard and also evaluated the ICCT and API cost studies.489 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 proposed averaging banking and trading 

(ABT) program that we were expected to propose, which would reduce the marginal 

costs of the Tier 3 proposed rule.

C. Summary of Proposed Program Costs

While the estimated costs for the separate proposed vehicle and proposed fuel 

programs are presented in Sections VII.A and VII.B, respectively, it is useful to present 

the combined cost estimates representing our full proposal. Such combined costs are also 

necessary in calculating the cost-effectiveness of the standards in today's proposal as 

described more fully in Section VII.D below.

We have chosen to use an annual, nationwide 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 proposed 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-8 below shows our estimated program costs by year. Complete details 

of this analysis can be found in the draft RIA.

Table VII-8 Total Annual Vehicle and Control Costs, 2010$

Year Vehicle Exhaust 

Emission Control 

Costs

($Million)

Vehicle Evaporative 

Emission Control 

Costs

($Million)

Facility Costs 

($Million)

Fuel Sulfur 

Control Costs

($Million)

Total 

Proposed 

Program Costs 

($Million)

2016 $0 $0 $22.5 $322 $345

2017 $634 $71.4 $3.75 $1,289 $1,998

2018 $1,170 $171 $3.75 $1,288 $2,628

 

489 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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2019 $1,270 $162 $3.75 $1,285 $2,725

2020 $1,380 $221 $3.75 $1,284 $2,884

2021 $1,510 $213 $3.75 $1,287 $3,017

2022 $1,630 $271 $3.75 $ 1,289 $3,189

2023 $1,660 $259 $3.75 $1,288 $3,208

2024 $1,770 $263 $3.75 $1,289 $3,329

2025 $1,870 $253 $3.75 $1,291 $3,421

2030 $1,790 $253 $3.75 $1,320 $3,370

Note: Costs shown include costs for the proposed Tier 3 standards on vehicles sold in all 

states except California.

D. Cost per Ton of Emissions Reduced

This section summarizes the cost per ton analysis conducted by EPA and its 

results. The emission reductions used to calculate the costs per ton reported here are 

consistent with those reductions presented as part of our inventory impacts analysis as 

described in Section III.B. The costs used to calculate the costs per ton are consistent 

with the vehicle and fuel control costs presented in Sections VII.A and VII.B, 

respectively. We have calculated the aggregate costs per ton which uses the costs and 

emission reductions for calendar years 2017 and 2030, consistent with the years that we 

evaluated for air quality analysis. For more information on how the cost per ton was 

calculated please refer to Section 8.2 of the draft RIA.

Note that, even though we are setting new standards for PM, we believe that those 

standards would be met in complying with the NMOG+NOX standards with additional 

care being given to proper engineering/calibration, so there is no cost associated with the 

new PM standard and therefore no separate cost per ton analysis for PM. Likewise, as 

described more fully in Sections IV.A and IV.B, while we are also proposing new 

standards for CO and formaldehyde, we are not attributing any of the control costs to 

these pollutants since the technologies employed to meet the NOX+NMOG standards 

would also allow the CO and formaldehyde standards to be met.

The total program costs, the NOX+VOC reductions, and results of our cost per ton

analysis are provided in Table VII-9. The costs of the proposed program would be higher 

immediately after it is implemented than they would be after several years, since both 

vehicle manufacturers and refiners can take advantage of decreasing capital and operating 

costs over time. In addition, the reductions in NOX and VOC emissions would become 

greater as a larger percentage of the fleet contains the technologies required to meet the 

proposed standards.
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Table VII-9 Costs per Ton of Emissions Reduced in 2017 and 2030

Total Proposed Program Cost 

($Million, 2010$)

Total NOX + VOC 

Reductions (tons)

Cost Effectiveness ($/ton)

2017 $1,999 329,162 $6,072

2030 $3,367 750,818 $4,484

Note: Costs shown include costs associated with the proposed Tier 3 vehicle and fuel in 

all states except California.

VIII.What are the Estimated Benefits of the Proposed Rule?

This section presents EPA’s analysis of the criteria pollutant-related health and 

environmental impacts that would occur as a result of the proposed Tier 3 standards. The 

vehicles and fuels subject to the proposed standards are significant sources of mobile 

source air pollution such as direct PM, NOX, SOX, VOCs and air toxics. The standards 

would affect 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 proposal, we have estimated the health and environmental impacts in 

2030, representing 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 proposed 

standards would lead to a net decrease in PM2.5- and ozone-related health impacts. The 

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 populationweighted annual average PM2.5 is 0.05 μg/m3

in 2030). The decrease in populationweighted national average ozone exposure results in a net decrease in ozone-related 

health impacts (population-weighted maximum 8-hour average ozone decreases by 0.52 

ppb in 2030).490

Using the lower end of EPA’s range of preferred premature mortality estimates

(Pope et al., 2002 for PM2.5 and Bell et al., 2004 for ozone),491,492 we estimate that by

2030, implementation of the proposed standards would reduce approximately 970 

 

490 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.

491 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.

492 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.
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premature mortalities annually and yield approximately $9.5 billion in total annual 

benefits. The upper end of the range of avoided premature mortality estimates associated 

with the proposed standards (based on Laden et al., 2006 for PM2.5 and Levy et al., 2005 

for ozone)493,494 results in approximately 2,800 premature mortalities avoided in 2030 and 

yields approximately $27 billion in total benefits. Thus, even using the lower end of the 

range of premature mortality estimates, the health impacts of the proposed standards 

presented in this rule would clearly 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 this proposal. For 

this reason, the Tier 3 emission control scenario used in the air quality and benefits 

modeling includes emission reductions from Tier 3 across the nation, assuming no 

reductions associated with California's LEV III program (as opposed to including 

California’s LEV III program and its associated emission reductions in the baseline 

scenario). This was because EPA had not granted California a waiver of preemption 

under CAA section 209 for the LEV III program at the time EPA conducted the air 

quality modeling. EPA did include California’s fuel program, which independent of LEV 

III was already resulting in average gasoline sulfur levels of 10 ppm, in the baseline 

scenario. Since then, EPA granted a waiver for California's LEV III program (78 FR 

2112, January 9, 2013) and ten states have adopted the LEV III program under Section 

177 of the Clean Air Act. Based on this change in circumstances, we will conduct new 

air quality modeling for the final rule that will include emission reductions from 

California’s LEV III program, both in California and in states that by that time have 

adopted the LEV III program, in the baseline scenario. 

Had we modeled the California LEV III emission impacts in the Tier 3 air quality 

baseline, we estimate that benefits would decrease by approximately 12-16 percent, 

depending on the particular health impact functions used to characterize both PM- and 

ozone-related premature mortality.

495

 As a result, we estimate that in 2030, using the 

lower end of EPA’s range of preferred premature mortality estimates (Pope et al., 2002 

for PM2.5 and Bell et al., 2004 for ozone), the proposed standards would reduce 

approximately 820 premature mortalities annually and yield approximately $8.0 billion in 

total annual benefits. The upper end of the range of avoided premature mortality

estimates associated with the proposed standards (based on Laden et al., 2006 for PM2.5

and Levy et al., 2005 for ozone) results in approximately 2,400 premature mortalities 

avoided in 2030 and yields approximately $23 billion in total benefits. These are rough 

estimates since, without new photochemical air quality modeling to reflect the revised 

 

493 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.

494 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.

495 To conduct this sensitivity analysis, we simply assumed no air quality change in the California portion 

of the CMAQ domain. We then exported the reference and control air quality surfaces to be used as inputs 

to BenMAP. Note that this simple approach is unable to account for legitimate emissions impacts related 

to cross-state transport of pollution.
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baseline and control scenarios, we are unable to account for cross-state transport of 

pollution into or out of California or Section 177 states. However, we believe this is a 

reasonable characterization of the small reduction in benefits had we modeled the 

emission reductions of the LEV III program in California and other state that adopt the 

LEV III program in the baseline. We believe our overall cost-benefit conclusions do not 

materially change with or without the inclusion of emission reductions from California 

and in other states that adopt the LEV III program in our analysis. We will conduct new 

air quality modeling for the final rule that will include emission reductions from the LEV 

III program in California, and in states that have adopted the program, in the baseline 

scenario. The rest of this section presents benefits that include emission reductions from 

the LEV III program.

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.496,497 These methods are described in 

more detail in the draft RIA that accompanies this action. Our benefits methods are also 

consistent with rulemaking analyses such as the final 2012-2016 MY Light-Duty Vehicle 

Rule,498 the final Portland Cement National Emissions Standards for Hazardous Air 

Pollutants (NESHAP) RIA,499 the final 2014-2018 MY Heavy-Duty Vehicle Rule,

500 and 

the final 2017-2025 MY Light-Duty Vehicle Rule.501 To model the ozone and PM air 

quality impacts of the proposed standards, we used the Community Multiscale Air 

 

496 U.S. Environmental Protection Agency. (2006). Final Regulatory Impact Analysis (RIA) for the 

Proposed National Ambient Air Quality Standards for Particulate Matter. Prepared by: Office of Air and 

Radiation. Retrieved March, 26, 2009 at http://www.epa.gov/ttn/ecas/ria.html

497 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

498 U.S. Environmental Protection Agency. (2010). Final Rulemaking to Establish Light-Duty Vehicle 

Greenhouse Gas Emission Standards and Corporate Average Fuel Economy Standards: Regulatory Impact 

Analysis, Assessment and Standards Division, Office of Transportation and Air Quality, EPA-420-R-10-

009, April 2010. Available on the internet: http://www.epa.gov/otaq/climate/regulations/420r10009.pdf

499 U.S. Environmental Protection Agency (U.S. EPA). (2010). Regulatory Impact Analysis: National 

Emission Standards for Hazardous Air Pollutants from the Portland Cement Manufacturing Industry. 

Office of Air Quality Planning and Standards, Research Triangle Park, NC. Augues. Available on the 

Internet at < http://www.epa.gov/ttn/ecas/regdata/RIAs/portlandcementfinalria.pdf >. EPA-HQ-OAR-2009-

0472-0241

500 U.S. Environmental Protection Agency. (2011). Final Rulemaking to Establish Greenhouse Gas 

Emissions Standards and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles: 

Regulatory Impact Analysis, Assessment and Standards Division, Office of Transportation and Air Quality, 

EPA-420-R-11-901, August, 2011. Available on the Internet at 

http://www.epa.gov/oms/climate/documents/420r11901.pdf.

501 U.S. Environmental Protection Agency. (2012). Regulatory Impact Analysis: Final Rulemaking for 

2017-2025 Light-Duty Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel Economy 

Standards, Assessment and Standards Division, Office of Transportation and Air Quality, EPA-420-R-12-

016, August 2012. Available on the internet: http://www.epa.gov/otaq/climate/documents/420r12016.pdf
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Quality (CMAQ) model (see Chapter 7.2.2 of the draft RIA that accompanies this 

preamble). The modeled ambient air quality data serves as an input to the Environmental 

Benefits Mapping and Analysis Program version 4.0 (BenMAP).502 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 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. The analysis of the proposed 

standards reflects EPA’s work to characterize benefits prior to the most recent PM 

NAAQS.

503

 EPA will update its benefits analysis, and related uncertainty analysis, to be 

consistent with the final PM NAAQS for the final Tier 3 regulatory impact analysis.

Table VIII-1 Estimated 2030 Monetized PM-and Ozone-Related Health Benefitsa,b

2030 Total Ozone and PM Benefits – PM Mortality Derived from American Cancer Society Analysis and 

Six-Cities Analysisb

Premature Ozone 

Mortality Function

Reference Total Benefits

(Billions, 2010$, 3% 

Discount Rate)c,d

Total Benefits

(Billions, 2010$, 7% 

Discount Rate) c,d

Multi-city analyses Bell et al., 2004 Total: $9.5 - $21

PM: $7.7 - $19

Ozone: $1.8

Total: $8.7 - $19

PM: $7.0 - $17

Ozone: $1.8

Huang et al., 2005 Total: $10 - $21

PM: $7.7 - $19

Ozone: $2.6

Total: $9.5 - $20

PM: $7.0 - $17

Ozone: $2.6

Schwartz, 2005 Total: $10 - $22

PM: $7.7 - $19

Ozone: $2.7

Total: $9.6 - $20

PM: $7.0 - $17

Ozone: $2.7

Meta-analyses Bell et al., 2005 Total: $13 - $24

PM: $7.7 - $19

Ozone: $5.5

Total: $12 - $23

PM: $7.0 - $17

Ozone: $5.5

Ito et al., 2005 Total: $15 - $26

PM: $7.7 - $19

Ozone: $7.5

Total: $15 - $25

PM: $7.0 - $17

Ozone: $7.5

Levy et al., 2005 Total: $15 - $27

PM: $7.7 - $19

Ozone: $7.7

Total: $15 - $25

PM: $7.0 - $17

Ozone: $7.7

a Benefits presented in this table include California emission reductions from the LEV III program. Had we 

modeled the California LEV III emission impacts in the Tier 3 air quality baseline, we estimate that 

 

502 Information on BenMAP, including downloads of the software, can be found at 

http://www.epa.gov/ttn/ecas/ benmodels.html.

503 U.S. EPA (2012). National Ambient Air Quality Standards for Particulate Matter. 

http://www.epa.gov/PM/2012/finalrule.pdf
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benefits would decrease by approximately 12-16 percent, depending on the particular health impact 

functions used to characterize both PM- and ozone-related premature mortality. We will account for 

emissions in states that have adopted California’s LEV III program in the baseline air quality modeling for 

the final rule.

b Total includes 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 (Pope et al., 2002) or the Six-Cities study 

(Laden et al., 2006).

c 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.

d 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 in Table VIII-1 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 and ozone 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 ozone and PM for which appropriate health impact 

functions are not available or which do not provide easily interpretable outcomes (e.g., 

changes in heart rate variability). Additionally, we are unable to quantify a number of 

known welfare effects, including reduced acid and particulate deposition damage to 

cultural monuments and other materials, and environmental benefits due to reductions of 

impacts of eutrophication in coastal areas. These are listed in Table VIII-2. As a result, 

the health benefits quantified in this section are likely underestimates of the total benefits 

attributable to the proposed standards.

Table VIII-2 Unquantified and Non-Monetized Potential Effects

Pollutant/Effects Effects Not Included in Analysis - Changes in:

Ozone Healtha Chronic respiratory damageb

Premature aging of the lungsb

Non-asthma respiratory emergency room visits

Exposure to UVb (+/-)

e

Ozone Welfare Yields for 

-commercial forests

-some fruits and vegetables

-non-commercial crops

Damage to urban ornamental plants

Impacts on recreational demand from damaged forest aesthetics

Ecosystem functions

Exposure to UVb (+/-)

e

PM HealthcPremature mortality - short term exposuresd

Low birth weight

Pulmonary function

Chronic respiratory diseases other than chronic bronchitis

Non-asthma respiratory emergency room visits

Exposure to UVb (+/-)

e

PM Welfare Residential and recreational visibility in non-Class I areas

Soiling and materials damage

Damage to ecosystem functions
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Exposure to UVb (+/-)

e

Nitrogen and 

Sulfate Deposition 

Welfare

Commercial forests due to acidic sulfate and nitrate deposition 

Commercial freshwater fishing due to acidic deposition 

Recreation in terrestrial ecosystems due to acidic deposition 

Existence values for currently healthy ecosystems 

Commercial fishing, agriculture, and forests due to nitrogen deposition 

Recreation in estuarine ecosystems due to nitrogen deposition

Ecosystem functions

Passive fertilization

CO Health Behavioral effects

HC/Toxics Healthf 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 non-asthmatics (formaldehyde)

Irritation of the eyes, skin, and respiratory tract (acetaldehyde)

Upper respiratory tract irritation and congestion (acrolein)

HC/Toxics Welfare Direct toxic effects to animals

Bioaccumulation in the food chain

Damage to ecosystem function

Odor

a

The public health impact of biological responses such as increased airway responsiveness to stimuli, 

inflammation in the lung, acute inflammation and respiratory cell damage, and increased susceptibility to 

respiratory infection are likely partially represented by our quantified endpoints.

b The public health impact of effects such as chronic respiratory damage and premature aging of the lungs 

may be partially represented by quantified endpoints such as hospital admissions or premature mortality, 

but a number of other related health impacts, such as doctor visits and decreased athletic performance, 

remain unquantified.

c

In addition to primary economic endpoints, there are a number of biological responses that have been 

associated with PM health effects including morphological changes and altered host defense mechanisms. 

The public health impact of these biological responses may be partly represented by our quantified 

endpoints.

d While some of the effects of short-term exposures are likely to be captured in the estimates, there may be 

premature mortality due to short-term exposure to PM not captured in the cohort studies used in this 

analysis. However, the PM mortality results derived from the expert elicitation do take into account 

premature mortality effects of short term exposures.

e May result in benefits or disbenefits.

f Many of the key hydrocarbons related to this action are also hazardous air pollutants listed in the CAA.

While there would be impacts associated with air toxic pollutant emission 

changes that result from the proposed standards, we do not attempt to monetize those 

impacts (Section III presents the estimated emission reductions associated with the 

proposal). 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 
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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 

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.504 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,505 EPA conducted a case study analysis of the 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.”506 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 proposed standards.507 

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 

proposed 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. 

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 

 

504 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.

505 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>.

506 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>.

507 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.
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that the proposed standards would result in between 800 and 2,100 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 270 and 2,700 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 170 to 770 fewer premature mortalities. 

Table VIII-3 Estimated PM2.5-Related Health Impactsa,b

Health Effect 2030 Annual 

Reduction in 

Incidence

(5th% - 95th%ile)

Premature Mortality – Derived from epidemiology literaturec

 Adult, age 30+, ACS Cohort Study (Pope et al., 2002)

 Adult, age 25+, Six-Cities Study (Laden et al., 2006)

 Infant, age <1 year (Woodruff et al., 1997)

800

(310 – 1,300)

2,100

(1,100 – 3,000)

3

(0 – 8)

Chronic bronchitis (adult, age 26 and over) 560

(100 – 1,000)

Non-fatal myocardial infarction (adult, age 18 and over) 980

(360 – 1,600)

Hospital admissions - respiratory (all ages)d160

(77 – 230)

Hospital admissions - cardiovascular (adults, age >18)e380

(270 – 440)

Emergency room visits for asthma (age 18 years and younger) 600

(350 – 850)

Acute bronchitis, (children, age 8-12) 1,300

(0 – 2,500)

Lower respiratory symptoms (children, age 7-14) 16,000

(7,700 – 24,000)

Upper respiratory symptoms (asthmatic children, age 9-18) 12,000

(3,800 – 20,000)

Asthma exacerbation (asthmatic children, age 6-18) 27,000

(3,000 – 74,000)

Work loss days 100,000

(88,000 – 110,000)

Minor restricted activity days (adults age 18-65) 600,000

(500,000 – 690,000)
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a Benefits presented in this table include California emission reductions from the LEV III 

program. We will account for emissions in states that have adopted California’s LEV III program 

in the baseline air quality modeling for the final rule.

b

Incidence is rounded to two significant digits. Estimates represent incidence within the 48 

contiguous United States. 

c

PM-related adult mortality based upon the American Cancer Society (ACS) Cohort Study 

(Pope et al., 2002) and the Six-Cities Study (Laden et al., 2006). Note that these are 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).508

d Respiratory hospital admissions for PM include admissions for chronic obstructive 

pulmonary disease (COPD), pneumonia and asthma.

e Cardiovascular hospital admissions for PM include total cardiovascular and subcategories 

for ischemic heart disease, dysrhythmias, and heart failure.

Table VIII-4 Estimated Ozone-Related Health Impactsa,b

Health Effect 2030 Annual Reduction 

in Incidence

(5th% - 95th%ile)

Premature Mortality, All agesc

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

170

(73 – 260)

250

(120 – 380)

260

(110 – 410)

540

(300 – 780)

750

(500 – 1,000)

770

(560 – 970)

Hospital admissions- respiratory causes (adult, 65 and 

older)d

1,200

(160 – 2,200)

Hospital admissions -respiratory causes (children, under 2) 550

(290 – 810)

Emergency room visit for asthma (all ages) 580

(0 – 1,500)

Minor restricted activity days (adults, age 18-65) 970,000

(490,000 – 1,500,000)

School absence days 350,000

(150,000 – 490,000)

 

508 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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a Benefits presented in this table include California emission reductions from the LEV III 

program. We will account for emissions in states that have adopted California’s LEV III 

program in the baseline air quality modeling for the final rule.

b

Incidence is rounded to two significant digits. Estimates represent incidence within the 

48 contiguous U.S. 

c 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 ozonerelated premature mortality should therefore not be summed.

d Respiratory hospital admissions for ozone include admissions for all respiratory causes 

and subcategories for COPD and pneumonia. 

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 2010$. 

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 $9.5 and $27 billion, assuming a 3 percent discount rate, or 

between $8.7 and $25 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 2010$) a,b

HEALTH ENDPOINTS 2030

(5TH AND 95

TH

PERCENTILE)

PM2.5-Related Health Effects

Premature Mortality – Derived 

from Epidemiology Studiesc,d

Adult, age 30+ - ACS study 

(Pope et al., 2002)

 3% discount rate

 7% discount rate

$7,200

($920 – $18,000)

$6,500

($830 - $17,000)

Adult, age 25+ - Six-Cities study 

(Laden et al., 2006)

 3% discount rate

 7% discount rate

$18,000

($2,600 - $45,000)

$17,000

($2,300 - $41,000)

Infant Mortality, <1 year –

(Woodruff et al. 1997)

$27

($0 - $100)

Chronic bronchitis (adults, 26 and over) $310

($25 - $1,000)

Non-fatal acute myocardial infarctions 

 3% discount rate

 7% discount rate

$110

($24 - $260)

$90

($19 - $210)

Hospital admissions for respiratory causes $2.5
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($1.2 – $3.6)

Hospital admissions for cardiovascular causes $5.5

($1.2 - $10)

Emergency room visits for asthma $0.24

($0.13 - $0.36)

Acute bronchitis (children, age 8–12) $0.61

($0.00 - $1.5)

Lower respiratory symptoms (children, 7–14) $0.34

($0.13 - $0.63)

Upper respiratory symptoms (asthma, 9–11) $0.40

($0.12 - $0.89)

Asthma exacerbations $1.6

($0.17 - $4.4)

Work loss days $16

($14 - $19)

Minor restricted-activity days (MRADs) $41

($24 - $59)

Ozone-Related Health Effects

Premature Mortality, All ages –

Derived from Multi-city analyses

Bell et al., 2004 $1,700

($220 - $4,200)

Huang et al., 2005 $2,500

($340 - $6,200)

Schwartz, 2005 $2,600

($330 - $6,500)

Premature Mortality, All ages –

Derived from Meta-analyses

Bell et al., 2005 $5,400

($760 - $13,000)

Ito et al., 2005 $7,400

($1,100 - $18,000)

Levy et al., 2005 $7,600

($1,100 - $18,000)

Hospital admissions- respiratory causes (adult, 65 and older) $32

($4.2 - $56)

Hospital admissions- respiratory causes (children, under 2) $6.0

($3.1 - $8.9)

Emergency room visit for asthma (all ages) $0.23

($0.0 - $0.57)

Minor restricted activity days (adults, age 18-65) $67

($31 - $110)

School absence days $34

($15 - $48)

a Benefits presented in this table include California emission reductions from the LEV III program. We 

will account for emissions in states that have adopted California’s LEV III program in the baseline air 

quality modeling for the final rule.

b Monetary benefits are rounded to two significant digits for ease of presentation and computation. PM and 

ozone benefits are nationwide. 

c Monetary benefits adjusted to account for growth in real GDP per capita between 1990 and the analysis 

year (2030).

d 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.
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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 draft RIA and its supporting references. 

Key uncertainties that have a bearing on the results of the benefit-cost analysis of the 

proposed 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 benefits 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:

 Inhalation of fine particles is causally associated with premature death at 

concentrations near those experienced by most Americans on a daily basis. 

Although biological mechanisms for this effect have not yet been completely

established, the weight of the available epidemiological, toxicological, and 

experimental evidence supports an assumption of causality. The impacts of 
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Page 380 of 995

including a probabilistic representation of causality were explored in the 

expert elicitation-based results of the PM NAAQS RIA.509 

 All fine particles, regardless of their chemical composition, are equally potent 

in causing premature mortality. This is an important assumption, because PM 

produced via transported precursors emitted from vehicle engines may differ 

significantly from PM precursors released from electric generating units and 

other industrial sources. However, no clear scientific grounds exist for 

supporting differential effects estimates by particle type.

 The C-R function for fine particles is approximately linear within the range of 

ambient concentrations under consideration. Thus, the estimates include 

health benefits from reducing fine particles in areas with varied concentrations 

of PM, including both regions that may be in attainment with PM2.5 standards 

and those that are at risk of not meeting the standards.

 There is uncertainty in the magnitude of the association between ozone and 

premature mortality. The range of ozone benefits associated with the 

coordinated strategy 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 ozonerelated mortality should be included in estimates of the health benefits of 

reducing ozone exposure.510 EPA has requested advice from the National 

Academy of Sciences on how best to quantify uncertainty in the relationship 

between ozone exposure and premature mortality in the context of quantifying 

benefits.

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 

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. 

 

509 U.S. Environmental Protection Agency. (2006). Final Regulatory Impact Analysis (RIA) for the 

Proposed National Ambient Air Quality Standards for Particulate Matter. Prepared by: Office of Air and 

Radiation. Retrieved March, 26, 2009 at http://www.epa.gov/ttn/ecas/ria.html

510 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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EPA addressed many of these comments in the analysis of the final PM NAAQS.511,512 

This analysis incorporates this work to the extent possible. 

E. Illustrative Analysis of Monetized Impacts Associated with the Proposal in 2017

For illustrative purposes, this section presents the total estimated monetized 

benefits associated with the proposed standards in 2017. As presented in Section III.B, 

the emissions impacts of the proposed standards in 2017 are primarily due to the effects 

of sulfur on the existing (pre-Tier 3) fleet. For reasons explained in Chapter 7.1.3.2.2 of 

the draft RIA, our analysis of the air quality impacts in 2017 reflects an increase in direct 

PM emissions from vehicles (along with reductions in NOX, VOCs and other pollutants). 

This emissions increase results from a series of conservative assumptions and 

uncertainties related to fuel parameters in 2017, and is not expected to occur in reality. 

Because our air quality modeling assumes this increase, as well as increased direct PM 

emissions due to an emissions processing error (see Chapter 7.2.1.1.2 of the draft RIA), 

our illustrative benefits analysis in 2017 overestimates ambient concentrations of PM2.5

and underestimates the benefits of the proposed Tier 3 standards. 

Table VIII-6 presents total aggregate monetized benefits of the program in 2017, 

which includes the modeled direct PM increase described above. Monetized estimates 

are presented in 2010$. Our estimate of total monetized benefits associated with the 

proposed standards in 2017, using the ACS and Six-Cities PM mortality studies and the 

range of ozone mortality assumptions, is between $1.0 and $3.4 billion, assuming a 3 

percent discount rate, or between $1.0 and $3.3 billion, assuming a 7 percent discount 

rate. Had our ambient air quality modeling of PM2.5 not included the increase in direct 

PM emissions, we estimate that benefits would increase by a range of $400 to $970 

million (assuming a 3 percent discount rate) or increase by a range of $360 to $880 

million (assuming a 7 percent discount rate), using current EPA benefit-per-ton estimates 

for direct PM.513

For a more detailed presentation of the quantified and monetized impacts of the 

proposal in 2017, please refer to Chapter 8 of the RIA that accompanies this preamble.

 

511 National Research Council (NRC). (2002). Estimating the Public Health Benefits of Proposed Air 

Pollution Regulations. The National Academies Press: Washington, D.C.

512 U.S. Environmental Protection Agency. (2006). Final Regulatory Impact Analysis (RIA) for the 

Proposed National Ambient Air Quality Standards for Particulate Matter. Prepared by: Office of Air and 

Radiation. Available at http://www.epa.gov/ttn/ecas/ria.html.

513 The PM2.5-related benefit-per-ton estimates provide the total monetized human health benefits (the sum 

of premature mortality and premature morbidity) of reducing one ton of directly emitted PM2.5. The benefit 

per-ton technique has been used in previous analyses, including the 2012-2016 Light-Duty Greenhouse Gas 

Rule (U.S. EPA, 2010. Regulatory Impact Analysis, Final Rulemaking to Establish Light-Duty Vehicle 

Greenhouse Gas Emission Standards and Corporate Average Fuel Economy Standards. Office of 

Transportation and Air Quality. April. Available at 

http://www.epa.gov/otaq/climate/regulations/420r10009.pdf. EPA-420-R-10-009). The benefits-per-ton 

values are available at http://www.epa.gov/oaqps001/benmap/bpt.html. Note that the values on the website 

are presented in year 2006$; the values underlying the estimates here have been adjusted to 2010$ using the 

CPI-U “all” index.
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Table VIII-6 Total Monetized Ozone and PM-related Benefits Associated 

with the Proposed Program in 2017

Total Ozone and PM Benefits (billions, 2010$) –

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

$1.0 - $1.8 Multi-city Bell et al., 

2004

$0.96 - $1.7

Huang et al., 

2005

$1.2 - $1.9 Huang et al., 

2005

$1.2 - $1.9

Schwartz, 

2005

$1.3 - $2.0 Schwartz, 

2005

$1.2 - $1.9

Meta-analysis Bell et al., 

2005

$2.1 - $2.8 Meta-analysis Bell et al., 

2005

$2.0 - $2.7

Ito et al., 

2005

$2.6 - $3.4 Ito et al., 

2005

$2.6 - $3.3

Levy et al., 

2005

$2.7 - $3.4 Levy et al., 

2005

$2.6 - $3.3

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

$0.68 - $3.8 Multi-city Bell et al., 

2004

$0.67 - $2.0

Huang et al., 

2005

$0.89 - $2.4 Huang et al., 

2005

$0.87 - $2.2

Schwartz, 

2005

$0.93 - $2.4 Schwartz, 

2005

$0.91 - $2.3

Meta-analysis Bell et al., 

2005

$1.7 - $3.2 Meta-analysis Bell et al., 

2005

$1.7 - $3.1

Ito et al., 

2005

$2.3 - $3.8 Ito et al., 

2005

$2.3 - $3.6

Levy et al., 

2005

$2.3 - $3.8 Levy et al., 

2005

$2.3 - $3.7

IX. Alternatives Analysis

As described throughout this preamble, we have considered a number of 

regulatory alternatives in the development of this proposal, including alternatives related 

to timing and stringency of the proposed standards, as well as program design (e.g., 

averaging, banking, and trading). This section summarizes the alternatives considered for 

both vehicle emission and fuel standards. 
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A. Vehicle Emission Standards

The federal vehicle emission standards we are proposing are the most stringent 

feasible considering anticipated developments in motor vehicle emissions control 

technology. As we considered options for these vehicle standards, one of the important 

factors we considered was harmonization with the CARB LEV III program. As a result, 

consideration of alternatives focused less on the level of the 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. 

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. 

1. Shorter NMOG+NOX Standard Phase-in

We originally considered requiring full implementation of the final NMOG+NOX

final fleet average standard by MY 2022. However, we determined that this would have 

disrupted the manufacturer’s normal product design cycles,514 and it would not have 

allowed manufacturers to use a consistent product design cycle for both the Tier 3 

standards and the 2017 LD GHG standards, which reach full implementation in MY 

2025. We are proposing to extend the phase-in schedule to MY 2025 in order to allow 

vehicle manufacturers to better integrate the compliance with Tier 3 into their product 

design cycles, as well as take advantage of additional learning to reduce costs. We 

believe this implementation schedule for the Tier 3 NMOG+NOX standards would allow 

us to achieve the environmental objectives without imposing unnecessary cost and 

burden on the industry.

2. Longer NMOG+NOX Standards Phase-in Due to Early Credits

In an effort to facilitate the step-down in fleet average stringency in the initial 

model years of the Tier 3 program, we considered allowing manufacturers to earn credits 

against the current Tier 2 Bin 5 fleet average and use earned early credits without any 

limits 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 not only delay achievement of the 

Tier 3 emission levels, but also delay harmonization between the Tier 3 and LEV III 

programs for many years. To address this potential misalignment, we are proposing that 

the application of the early credits be capped starting in MY 2018 at a manufacturer’s 

LEV III credits adjusted by the ratio of California and Section 177 state sales to federal 

sales. (See Section IV.A.7.a for more details.) This proposed approach would balance 

the need for some transition flexibility to avoid unnecessary costs, while still ensuring 

 

514 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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expeditious harmonization with LEV III and achievement of the environmental benefits 

of the Tier 3 standards.

3. Shorter PM Standards Phase-in

As we considered potential PM phase-in schedules, we gave strong consideration 

to manufacturers’ PM testing capabilities and product design cycles. We considered 

requiring manufacturers to certify 25 percent of their fleet to the Tier 3 PM standards in 

MY 2017, ramping up to 100 percent by MY 2020. We initially believed that this 

schedule would allow manufacturers to focus engineering resources on ensuring their 

new products meet the proposed Tier 3 standards while other product lines, which we 

expect would be phased out due to the 2017 LD GHG standards, expire. However, based 

on further discussions with the vehicle manufacturers, we recognized that they need time 

to improve and expand their facilities to measure PM, not only for compliance 

determination but also for product development work prior to production. As a result, we 

are proposing a phase-in schedule for meeting the proposed Tier 3 PM standards that 

starts with 20 percent of the vehicles at or below 6000 lbs GVWR in MY 2017 and ramps 

up to 100 percent of the light-duty fleet in MY 2021. As with the NMOG+ NOX phase-in 

discussed above, we believe this proposed phase-in schedule for the Tier 3 PM standards 

would allow us to achieve the environmental objectives without imposing unnecessary

cost and burden on the industry.

4. NMOG+NOX Standards

We believe that the fleet-average NMOG+NOX standards that we are proposing 

reflect the greatest degree of emission reduction achievable considering cost and 

technology, assuming that gasoline sulfur levels are reduced to the proposed 10-ppm 

average. We also believe the proposed implementation schedule for the NMOG+ NOX

standards is as short as practicable, as explained above. As a result, we believe more 

stringent standards would not be justified based on the information currently available to 

EPA. Therefore, given our goal to harmonize our program with CARB’s at the 30 

mg/mi level, we did not conduct any detailed analysis of a less stringent fleet average 

standard. Based on the work done to quantify the impacts of the 30 mg/mi standard, 

however, we can say that a fleet-average standard of 50 mg/mi of NMOG+NOX would 

result in NMOG+NOX emissions in 2030 that are about 100,000 tons higher than the 

standards we are proposing. While costs would be lower because the emissions controls 

discussed in Section VII.A would be applied at a lower rate, such a standard would also 

not be harmonized with CARB LEV III standards. 

5. PM Standards

The FTP PM standards that we are proposing are the most stringent technically

feasible standards within the implementation timeframe of this proposal. Although 

CARB has finalized a 1 mg/mi standard which will begin phasing in with MY 2025, they
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acknowledge that there is a need for continuing PM measurement method development 

prior to implementing this standard.515 The EPA believes that in order to propose a 

federal PM standard at this level, there should be established methods to reliably and 

consistently measure PM at levels at and below that standard that would be needed for 

ensuring compliance. 

B. Fuel Sulfur Standards

As explained in Section V.A.2., we believe that a 10-ppm annual average standard 

is sufficient to enable the vehicle fleet to meet the proposed 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. Because vehicle emission performance improves as sulfur 

is reduced, we considered imposing a 10-ppm cap (i.e., no averaging, banking and 

trading), as well as lowering gasoline sulfur content below the 10-ppm average (see 

Section V.A.6). 

We considered expressing the standard as a cap similar to the standard in Europe 

and Japan. 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 10 

percent, and would still be sufficient to enable vehicles to meet the proposed Tier 3 

standards.

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 80,000 tons in 2017.

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) more overcapacity and storage for reprocessing of off-specification product;

(3) treatment of additional (non-FCC) gasoline blendstocks; (4) essentially all refineries 

to reduce sulfur to 5 ppm, thereby eliminating much of the benefit of the ABT provisions, 

and (5) 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 more than 50 percent greater than for our proposed 10-ppm 

standard. This is more than twice as high on a cost per ppm-gallon basis. Additionally, as 

explained earlier, a 5 ppm standard would likely result in the elimination of the ability for 

 

515 California Air Resources Board (CARB) Initial Statement of Reasons, Public Hearing to Consider LEV 

III, December 7, 2011
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refineries to trade credits. Without a viable trading program it could become 

prohibitively expensive for the more challenged refineries to comply, creating a financial 

hardship situation. 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.

In addition to lower average sulfur standards, we are also considering lower pergallon cap standards, which are currently set under the Tier 2 program at 80 ppm sulfur at 

the refinery gate and 95 ppm sulfur downstream. As discussed in Section V.A.3., in 

addition to proposing that these cap standards be maintained, we are co-proposing 

lowering them to 50 ppm and 65 ppm respectively. Given the stringency of the 10-ppm 

average standard, we do not anticipate that this would have a meaningful impact on either 

program costs or emission reductions. However, it would provide added assurance that 

individual vehicles would not be exposed to higher sulfur levels and the resulting impacts 

on emissions. Vehicle manufacturers have expressed concern that such exposure could 

impact not only individual vehicle emissions, but also vehicle operation, due to 

interference with sensors and feedback controls. To further address concerns of vehicle 

manufacturers, we are also requesting comment on the potential implementation of a 

refinery gate sulfur cap as low as 20 ppm and a downstream sulfur cap as low as 25 ppm. 

This would further constrain downstream contamination and limit the temporary

exposure of vehicles in-use to sulfur levels that would significantly degrade their 

emission performance. 

X. Economic Impact Analysis

A. Introduction

The proposed rule would affect two sectors directly: vehicle manufacturing and 

petroleum refining. For these two regulated sectors, the economic impact analysis 

discusses the market impacts from the proposed rule, the 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. The recently issued 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 proposal on employment in the regulated sectors.

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 proposed standards at the aggregate market level. Vehicle 

manufacturers are expected to comply with the proposed standards primarily through 
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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 proposed 

standards. These costs differ across years and range from $71 to $102 for cars, $93 to 

$150 for trucks and $36 to $59 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’ costs of vehicle production.516 We do not quantify the expected 

level of cost pass-through 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 

increased 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 would be 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.

C. Impacts on Petroleum Refinery Sector Production

The key change for refiners from the proposed standards would be more stringent 

sulfur requirements. This change to fuels is expected to increase manufacturers’ costs of 

gasoline production by about 0.9 cents per gallon (see Section VII.B).

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 

 

516 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 () who found significantly less than full-cost passthrough 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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most levels of the petroleum industry has remained low to moderate.”517 Thus the 

assumption of competitive markets has some foundation in this industry. We do not 

estimate the price increase that consumers are likely to face, though we note that it should 

be positive and up to the increase in manufacturers’ costs of gasoline production. 

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 

proposed 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 proposed 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 proposed rule. We partially quantify impacts in the auto sector, 

providing a mix of qualitative and 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.518 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 would use to comply

with the proposed standards.

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. 

 

517 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 .

518 77 FR 62623 (October 15, 2012).
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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.519 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.”

We follow the theoretical structure proposed in a study by Morgenstern, Pizer, 

and Shih (2002)520 of the impacts of regulation in employment in the regulated sectors. 

In particular, Morgenstern et al. (2002) identify three separate ways that employment 

levels may change in the regulated industry in response to a new or more stringent 

regulation. 

 Demand effect: higher production costs due to the regulation will lead to 

higher market prices; higher prices in turn reduce demand for the good, 

reducing the demand for labor to make that good. In the authors’ words, the 

“extent of this effect depends on the cost increase passed on to consumers as 

well as the demand elasticity of industry output.”

 Cost effect: as costs go up, plants add more capital and labor (holding other 

factors constant), with potentially positive effects on employment; in the 

authors’ words, as “production costs rise, more inputs, including labor, are 

used to produce the same amount of output.” 

 Factor-shift effect: post-regulation production technologies may be more or 

less labor-intensive (i.e., more/less labor is required per dollar of output). In 

the authors’ words, “environmental activities may be more labor intensive 

than conventional production,” meaning that “the amount of labor per dollar 

of output will rise,” though it is also possible that “cleaner operations could 

involve automation and less employment, for example.”

The authors note that the demand effect is expected to have a negative effect on 

employment, the cost effect to have a positive effect on employment, and the factor-shift 

effect to have an ambiguous effect on employment. 

 

519 Schmalensee, R., & Stavins, R. (2011). A Guide to Economic and Policy Analysis of EPA’s Transport 

Rule” White paper commissioned by Excelon Corporation ().

520 Morgenstern, R., Pizer, W., & Shih, J. (2002). Jobs Versus the Environment: An Industry-Level 

Perspective. Journal of Environmental Economics and Management 43, 412-436.
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Morgenstern et al. (2002) estimated the effects on employment of spending on 

pollution abatement for four highly polluting/regulated industries (pulp and paper, 

plastics, steel, and petroleum refining) using data for six years between 1979 and 1991. 

They concluded that increased abatement expenditures generally have not caused a 

significant change in employment in those sectors. More specifically, their results 

showed that, on average across the industries studied, each additional $1 million (1987$) 

spent on pollution abatement resulted in a (statistically insignificant) net increase of 1.5 

jobs. In the petroleum refining industry in particular, they found statistically significant 

and positive cost and factor shift effects and an insignificant demand effect, for a net 

(statistically significant) increase of 2.17 jobs per $1 million (1987$).

1. Employment Impacts in the Auto Sector

Following the Morgenstern et al. (2002) framework, we consider three effects for 

the auto sector: the demand effect, the cost effect, and the factor shift effect.

a. The Demand Effect

The demand effect depends on the effects of this proposal on vehicle sales. If 

vehicle sales decrease, employment associated with these activities would decrease. As 

discussed in Section X.B, we do not make a quantitative estimate on the effect of the 

proposed 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 

demand effect to be small as well.

b. The Cost Effect

The demand effect, above, measures the effect due to new vehicle sales only. The 

cost effect measures the impacts due to the changes in technologies for vehicles that 

would have been sold in the absence of the rule. We estimate the cost 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. 

Some of the costs of this proposal would be spent directly in the auto 

manufacturing sector, but it is also likely that some of the costs would 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. The U.S. Bureau of Labor Statistics (BLS) provides its Employment 

Requirements Matrix (ERM),521 which provides direct estimates of the employment per 

$1 million in sales of goods in 202 sectors. The values considered here are for Motor 

 

521 Bureau of Labor Statistics. Employment Requirements Matrix. 

http://www.bls.gov/emp/ep_data_emp_requirements.htm
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Vehicle Manufacturing (NAICS 3361) and Motor Vehicle Parts Manufacturing (NAICS 

3363). 

The Census Bureau provides both the Annual Survey of Manufactures522 (ASM) 

and the Economic Census. The ASM is a subset of the Economic Census, based on a 

sample of establishments; though the Census itself is more complete, it is conducted only 

every 5 years, while the ASM is annual. Both include more sectoral detail than the BLS 

ERM: for instance, while the ERM includes the Motor Vehicle Manufacturing sector, the 

ASM and Economic Census have detail at the 6-digit NAICS code level (e.g., light truck 

and utility vehicle manufacturing). While the ERM provides direct estimates of 

employees/$1 million in expenditures, the ASM and Economic Census separately provide 

number of employees and value of shipments; the direct employment estimates here are 

the ratio of those values. The values reported are for Motor Vehicle Manufacturing 

(NAICS 3361), Automobile and Light Duty Motor Vehicle Manufacturing (NAICS 

33611), and Motor Vehicle Parts Manufacturing (NAICS 3363).

For the cost effect, we use estimates from the Bureau of Labor Statistics and the 

Census Bureau of the number of workers per $1 million of expenditures in the sectors. 

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, as the factor-shift effect indicates. For instance, the ratio for the motor 

vehicle manufacturing sector represents the ratio for all vehicle manufacturing, not just 

for emissions reductions. 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 0.667.523 As discussed 

in the draft RIA, trends in the BLS ERM are used to estimate productivity improvements 

over time that are used to adjust these ratios over time.

 

522 U.S. Census Bureau. Annual Survey of Manufactures. 

http://www.census.gov/manufacturing/asm/index.html

523 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.
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Table X-1 provides estimates of the cost effect of this rule on employment. 

Chapter 2.1 of the draft 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 (before adjustments for changes in productivity, after 

accounting for the share of domestic production) is 1.809 if all the additional costs are in 

the parts sector; the minimum value is 0.402, if all the additional costs are in the lightduty vehicle manufacturing sector. Increased costs of vehicles and parts would, by

itself, be expected to increase employment between 2017 and 2025 by somewhere 

between a few hundred to a few thousand jobs.

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 $ 23 0 0 

2017 $ 709 + 900 +200 

2018 $ 1,340 +1,700 +400 

2019 $ 1,440 +1,800 +400 

2020 $ 1,600 +1,900 +400 

2021 $ 1,730 +2,000 +400 

2022 $ 1,900 +2,100 +400 

2023 $ 1,920 +2,000 +400 

2024 $ 2,040 +2,100 +400 

2025 $ 2,130 +2,100 +400 

c. The Factor Shift Effect

The factor shift effect looks at the changes in labor intensity associated with a 

regulation. As noted above, the estimates of the cost effect assume constant labor per $1 

million in expenditures, though the new technologies may be either more or less laborintensive than the existing ones. We have no evidence on the factor shift effect for the 

compliance technologies and therefore do not quantify it. An estimate of the factor shift 

effect would either increase or decrease the estimate used for the cost effect.

d. Summary of Employment Effects in the Auto Sector

The overall effect of the proposed rule on auto sector employment depends on the 

relative magnitude of the cost effect, the demand effect and the factor shift effect. 

Because we do not have quantitative estimates of the demand and factor shift effects we 
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cannot reach a quantitative estimate of the overall employment effects of the proposed 

rule on auto sector employment or even whether the total effect would 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. Additionally, the cost and demand effects are expected to work in 

opposite directions. Thus while we do not have an estimate of the direction of the overall 

effect of the proposed rule on auto sector employment, we expect it will be imperceptible.

Additionally, the proposed rule is not expected to provide incentives for 

manufacturers to shift employment between domestic and foreign production. This is 

because the increased standards of the proposed rule would 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 proposal, there may be some 

initial incentive for foreign production, but the opportunity for the U.S. to sell in other 

markets might increase. To the extent that the requirements of this proposal 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 would not apply if other countries 

are not likely to have similar standards.

2. Refinery Employment Impacts

The Morgenstern et al. (2002) framework of demand effects, cost effects and 

factor shift effects can also be applied to the impact of the proposed 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 demand effect on refining sector 

employment is expected to be negative. The discussion in Section X.C above suggested 

that the proposed rule would 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 would 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 the standards proposed here is expected to 

decrease by only a very small amount over any time horizon. 

The cost effect of the proposed rule on employment in the refining sector is 

expected to be positive as usual in the Morgenstern et al. (2002) framework. In order to 

satisfy the requirements of the proposed rule, firms in the refining industry are expected 

to need to perform additional work that will require hiring more employees, especially 

perhaps in the short run. Section V.A.2.c discusses the expected employment needed to 

reduce the sulfur content of fuels; as noted there, to meet the proposed Tier 3 sulfur 

standards, refiners are expected to invest $2.2 billion between 2014 and 2019 and utilize 

approximately 1,000 front-end design and engineering jobs and 6,000 construction jobs. 

As the petroleum sector employed approximately 65,000 workers in 2009, this temporary

increase in employment would be comparable to an increase of over 10 percent when 

compared to 2009 levels.
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As with our analysis of the vehicle manufacturing sector, we do not have 

information on the direction the factor shift effect might take. It is unclear whether the 

refining industry would become more or less capital intensive as a result of the proposed 

rule. Thus the direction of the factor shift effect is ambiguous. 

This rule is not expected to provide incentives to shift employment between 

domestic and foreign production. First, the proposed standards would 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 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.

524

 In this case, what is relevant is 

whether the necessary modifications to comply with Tier 3 would 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.

 

524 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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Thus it is expected that for the refining sector, the demand effect would lower 

employment, the cost effect would raise employment, and the factor shift effect would 

have an ambiguous effect on employment. As a whole then, it is not evident whether the 

proposed rule would increase or decrease employment in the refining sector. However, 

given the small anticipated reduction in quantity sold, it appears that the rule would not 

have major employment consequences for this sector. 

The petroleum industry is one of the four industries studied by Morgenstern et al. 

(2002) when they look at the effect of environmental expenditures on employment. They

found a small but statistically significant increase in employment in this sector (2.17 jobs 

per million dollars of expenditures, using 1987$). Using this factor (adjusted to 2010$), 

the estimated sulfur fuel control costs in 2017 of $1,289 million would imply an increase 

of approximately 1,600 jobs in the refinery sector. We note that the regulations that this 

estimate is derived from are not directly comparable to the current proposed rule; it is 

based on the costs of reductions in refinery emissions instead of changing fuel properties, 

and therefore may not be applicable for the standards proposed here.

Section 5.3 of the draft 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 net 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 proposed 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 proposed rule is 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 

would 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 

in the ongoing compliance phase. It is expected that the employment increases through 

the cost 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 demand effect would not start until 2017, when compliance would 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.
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XI. Public Participation

We request comment on all aspects of this proposal. This section describes how 

you can participate in this process.

A. How Do I Submit Comments?

EPA will announce the comment period and the public hearing dates for this 

proposal in a supplemental Federal Register Notice. . We will accept comments during 

the period indicated in the supplemental notice. If you have an interest in the proposed 

program described in this document, we encourage you to comment on any aspect of this 

rulemaking. We also request comment on specific topics identified throughout this 

proposal.

Your comments will be most useful if you include appropriate and detailed 

supporting rationale, data, and analysis. Commenters are especially encouraged to 

provide specific suggestions for any changes to any aspect of the regulations that they 

believe need to be modified or improved. You should send all comments, except those 

containing proprietary information, to our Air Docket (see ADDRESSES in the first part 

of this proposal) before the end of the comment period.

You may submit comments electronically, by mail, or through hand 

delivery/courier. To ensure proper receipt by EPA, identify the appropriate docket 

identification number in the subject line on the first page of your comment. Please ensure 

that your comments are submitted within the specified comment period. Comments 

received after the close of the comment period will be marked “late.” EPA is not 

required to consider these late comments. If you wish to submit Confidential Business 

Information (CBI) or information that is otherwise protected by statute, please follow the 

instructions in Section XI.B.

B. How Should I Submit CBI to the Agency?

Do not submit information that you consider to be CBI electronically through the 

electronic public docket, www.regulations.gov, or by e-mail. Send or deliver information 

identified as CBI only to the following address:

U.S. Environmental Protection Agency, Assessment and Standards Division, 2000 

Traverwood Drive, Ann Arbor, MI, 48105, Attention Docket ID EPA–HQ– OAR–2011–

0135. You may claim information that you submit to EPA as CBI by marking any part or 

all of that information as CBI (if you submit CBI on disk or CD–ROM, mark the outside 

of the disk or CD–ROM as CBI and then identify electronically within the disk or CD–

ROM the specific information that is CBI). Information so marked will not be disclosed 

except in accordance with procedures set forth in 40 CFR part 2.

In addition to one complete version of the comments that include any information 

claimed as CBI, a copy of the comments that does not contain the information claimed as 

CBI must be submitted for inclusion in the public docket. If you submit the copy that 
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does not contain CBI on disk or CD–ROM, mark the outside of the disk or CD–ROM 

clearly that it does not contain CBI. Information not marked as CBI will be included in 

the public docket without prior notice. If you have any questions about CBI or the 

procedures for claiming CBI, please consult the person identified in the FOR FURTHER 

INFORMATION CONTACT section.

C. What Should I Consider as I Prepare My Comments for EPA?

You may find the following suggestions helpful for preparing your comments:

 Explain your views as clearly as possible.

 Describe any assumptions that you used.

 Provide any technical information and/or data you used that support 

your views.

 If you estimate potential burden or costs, explain how you arrived at 

your estimate.

 Provide specific examples to illustrate your concerns.

 Offer alternatives.

 Make sure to submit your comments by the comment period deadline 

identified.

 To ensure proper receipt by EPA, identify the appropriate docket 

identification number in the subject line on the first page of your 

response. It would also be helpful if you provided the name, date, and 

Federal Register citation related to your comments.

D. Will There Be a Public Hearing?

EPA will announce the public hearing dates for this proposal in a supplemental 

Federal Register Notice. 

If you would like to present testimony at the public hearing, we ask that you 

notify the contact person listed under FOR FURTHER INFORMATION CONTACT in 

the first part of this proposal at least seven days before the hearing. Once EPA learns

how many people have registered to speak at the public hearing, we will allocate an 

appropriate amount of time to each participant, allowing time for lunch and necessary

breaks throughout the day. For planning purposes, each speaker should anticipate 

speaking for approximately ten minutes, although we may need to adjust the time for 

each speaker if there is a large turnout. We suggest that you bring copies of your 

statement or other material for the EPA panel and the audience. It would also be helpful 

if you send us a copy of your statement or other materials before the hearing. To 
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accommodate as many speakers as possible, we prefer that speakers not use technological 

aids (e.g., audio-visuals, computer slideshows). However, if you plan to do so, you must 

notify the contact persons in the FOR FURTHER INFORMATION CONTACT section 

in the supplemental hearing notice. You also must make arrangements to provide your 

presentation or any other aids to EPA in advance of the hearing in order to facilitate setup. 

We will make a tentative schedule for the order of testimony based on the 

notifications we receive. This schedule will be available on the morning of the hearing. 

In addition, we will reserve a block of time for anyone else in the audience who wants to 

give testimony.

The hearing will be held at a site accessible to individuals with disabilities. 

Individuals who require accommodations such as sign language interpreters should 

contact the persons listed under FOR FURTHER INFORMATION CONTACT section in 

the supplemental hearing notice seven days before the date of the hearing.

We will conduct the hearing informally, and technical rules of evidence will not 

apply. We will arrange for a written transcript of the hearing and keep the official record 

of the hearing open for 30 days to allow you to submit supplementary information. You 

may make arrangements for copies of the transcript directly with the court reporter.

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 

preamble and in Chapter 8 of the draft RIA. A copy of the analysis is available in the 

docket for this action.

B. Paperwork Reduction Act

The information collection requirements in this proposed rule have been 

submitted for approval to the Office of Management and Budget (OMB) under the 

Paperwork Reduction Act, 44 U.S.C. 3501 et seq. The Information Collection Request 

(ICR) documents prepared by EPA have been assigned EPA ICR number 0783.63 for the 

vehicles provisions and EPA ICR 2482.01 and ICR 2459.01 for the fuels provisions.
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This proposed rule contains reporting and recordkeeping requirement within the 

context of EPA’s motor vehicle certification program and the manufacturers’ in-use 

testing program (IUVP). Current regulations require manufacturers to submit emissions 

information to EPA in conjunction with these two programs (Information Collections). 

Manufacturers must submit an application for emission certification prior to production. 

The application describes the major aspects of the proposed product line, technical details 

of the emission control systems, and the results of tests to indicate compliance with the 

emissions and, greenhouse gases, and fuel economy 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.

This proposed rule also contains reporting and recordkeeping requirements for 

refiners and importers of motor vehicle gasoline. The recordkeeping and reporting 

requirements for these entities under the proposed Tier 3 program are the same 

requirements that exist under the Tier 2 sulfur program.525 The recordkeeping and 

Product Transfer Document (PTD) requirements for gasoline additive producers and PTD 

requirements for downstream parties under the proposed Tier 3 program are new but 

should be minimal since we expect that they are already followed as part of normal 

business practices. Finally, there are new recordkeeping and PTD requirements for 

producers of denatured fuel ethanol under the proposed Tier 3 program EPA estimates 

the total number of respondents to be 1500, the total burden hours to be 76,743 and the 

total cost to respondents to be $5,908,504.

Finally, this proposed rule also contains provisions for qualifications of 

laboratories on test methods. We have proposed 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 proposed 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.

Supporting statements for all 3 ICRs can be found in Docket ID number EPA–

HQ–OAR–2011–0135.

 

525 65 FR 6698, February 10, 2000; OMB Control Number: 2060-0437; EPA ICR 1907.05
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Burden is defined at 5 CFR 1320.3(b).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.

To comment on the Agency’s need for this information, the accuracy of the 

provided burden estimates, and any suggested methods for minimizing respondent 

burden, EPA has established a public docket for this rule, which includes these ICR

numbers, under Docket ID number EPA–HQ–OAR–2011–0135. See the 

‘ADDRESSES’ section at the beginning of this notice for where to submit comments to 

EPA. Send comments to OMB at the Office of Information and Regulatory Affairs, 

Office of Management and Budget, 725 17th Street, NW, Washington, DC 20503, 

Attention: Desk Office for EPA. Since OMB is required to make a decision concerning 

the ICR between 30 and 60 days after [Insert date of publication in the FEDERAL 

REGISTER], a comment to OMB is best assured of having its full effect if OMB 

receives it by [Insert date 30 days after publication in the FEDERAL REGISTER]. 

The final rule will respond to any OMB or public comments on the information collection 

requirements contained in this proposal. 

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
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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

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 Rule526 in 

exchange for early compliance with the diesel program. Similar to the Tier 2 rule, the 

Tier 3 rule being proposed today 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) that examines the impact of the proposed rule on small entities along 

 

526 66 FR 5136 (January 18, 2001).
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with regulatory alternatives that could reduce that impact. The IRFA is available for 

review in the rulemaking docket (in Chapter 10 of the draft RIA) and is summarized 

below.

As required by section 609(b) of the RFA, as amended by SBREFA, EPA also 

conducted outreach to small entities and convened a Small Business Advocacy Review 

Panel to obtain advice and recommendations of representatives of the small entities that 

potentially would be subject to the rule’s requirements.

Consistent with the RFA/SBREFA requirements, the Panel evaluated the 

assembled materials and small-entity comments on issues related to elements of the 

IRFA. A copy of the Panel Report is included in the docket for this proposed rule, and a 

summary of the Panel process, and subsequent Panel recommendations, is summarized 

below.

3. Reason for Today’s Proposed Rule

This rule proposes to establish more stringent vehicle emissions standards and 

reduce 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 

proposed gasoline sulfur standard would make emission control systems more effective 

and enable more stringent vehicle emissions standards, and the proposed vehicle 

standards would reduce vehicle tailpipe and evaporative emissions. This would 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 proposed rule, please see Sections II 

and III of this preamble. The proposed 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 proposed 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 proposed 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.G of this preamble.

5. Summary of Potentially Affected Small Entities

The table above lists industries/sectors potentially affected by the proposed rule. 

For businesses potentially impacted by the Tier 3 vehicle standards, this includes vehicle 
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manufacturers, alternative fuel converters, and independent commercial importers. For 

businesses potentially impacted by the Tier 3 fuel standards, this includes gasoline 

refiners and importers, distributors, fuel additive manufacturers, transmix producers, 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 

business information database Hoover’s Online (a subsidiary of Dun and Bradstreet). 

These entities fall under the categories listed in the table.

To gauge the impact of the proposed standards on small businesses, EPA 

employed a cost-to-sales ratio test to estimate the number of small businesses that would 

be impacted by less than one percent, between one and three percent, and above three 

percent. Overall, EPA projects that 13 small businesses will be impacted by less than one 

percent, 13 small businesses will be impacted by one to three percent, and 5 small 

businesses will be impacted by more than three percent. A more detailed description of 

the inputs used for each affected industry sector and the methodology used to develop the 

estimated impact on small businesses in each industry sector is included in the IRFA as 

presented in Chapter 10 of the draft RIA for this rulemaking.

6. Potential 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 considering for manufacturers 

subject to this proposal will include testing, reporting, and record keeping requirements 

for manufacturers of vehicles covered by the proposed Tier 3 regulations. Testing 

requirements for these manufacturers could include certification emission (including 

deterioration factor) testing, in-use testing, and production line testing. Reporting 

requirements would likely include emission test data and technical data on the vehicles. 

Manufacturers would have to keep records of this information.

For any fuel control program, EPA must have assurance that fuel produced, 

distributed, sold and used meets the applicable standard. EPA expects that the 

recordkeeping, reporting, and compliance provisions of the proposed rule would be fairly 

consistent with those in place today for other fuel programs. Further, we expect to 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 the proposed Tier 3 rule under 

consideration are: the Tier 2 Vehicle/Gasoline Sulfur rulemaking (65 FR 6698, February
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10, 2000), the 2017 Light-duty Greenhouse Gas (GHG) rule (77 FR 62623), and the 

Petroleum Refinery Sector Risk and Technology Review and New Source Performance 

Standards rule (RTR/NSPS; 77 FR 41051). 

The 2017 LD GHG rule is a coordinated effort by EPA and the National Highway

Traffic Safety Administration (NHTSA) taking steps to enable the production of a new 

generation of clean vehicles, though reduced GHG emissions and improved fuel 

efficiency from on-road vehicles and engines.

The rules to address Petroleum Refinery Sector Risk and Technology Review 

(RTR) and New Source Performance Standards (NSPS) focus on developing updated 

emissions standards for petroleum refineries for multiple pollutants, including GHGs. 

The rules are based on results of the RTR analyses for both Maximum Achievable 

Control Technology standards (MACT 1 and 2). The technology review would be 

conducted to identify any new practices, processes, or control technologies for the 

industry and cost-effective emission control options. EPA is developing uniform 

standards for some emission sources in the petroleum refining sector that may serve as 

the basis for these technology reviews. The rules also review the standards and rule 

provisions to determine whether other changes may be needed during periods of start-up, 

shutdown, and malfunction to ensure the standards are consistent with recent court 

opinions and other CAA programs. With regard to NSPS, the rules address remaining 

NSPS issues under reconsideration from the promulgation of existing NSPS and other 

NSPS rules affecting the refining sector, and include the regulation of GHGs and the 

development of emission guidelines for existing sources.

8. Summary of SBREFA Panel Process and Panel Outreach

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. The recommendations of the Panel are described 

below and are also located in Section 9 of the SBREFA Final Panel Report, which is 

available in the public docket.

b. Panel Process

As required by section 609(b) of the RFA, as amended by SBREFA, we also 

conducted outreach to small entities and convened an SBAR Panel to obtain advice and 

recommendations of representatives of the small entities that potentially would be subject 

to the rule’s requirements. On August 4, 2011, EPA’s Small Business Advocacy

Chairperson convened a Panel under Section 609(b) of the RFA. In addition to the Chair, 

the Panel consisted of the Division Director of the Assessment and Standards Division of 

EPA’s Office of Transportation and Air Quality, the Chief Counsel for Advocacy of the 

Small Business Administration, and the Administrator of the Office of Information and 
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Regulatory Affairs within the Office of Management and Budget. As part of the SBAR 

Panel process, we conducted outreach with representatives of small businesses that would 

potentially be affected by the proposed rulemaking. We met with these Small Entity

Representatives (SERs) to discuss the potential rulemaking approaches and potential 

options to decrease the impact of the rulemaking on their industries. We distributed 

outreach materials to the SERs; these materials included background on the rulemaking, 

possible regulatory approaches, and possible rulemaking alternatives. The Panel met 

with SERs from the industries that would be directly affected by the Tier 3 rule on 

August 18, 2011 to discuss the outreach materials and receive feedback on the 

approaches and alternatives detailed in the outreach packet (the Panel also met with SERs 

on June 28, 2011 for an initial outreach meeting). The Panel received written comments 

from the SERs following the meeting in response to discussions had at the meeting and 

the questions posed to the SERs by the Agency. The SERs were specifically asked to 

provide comment 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 summary of these recommendations is detailed below, and 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. A complete discussion of the 

provisions for which we are requesting comment and/or proposing in this action can be 

found in Sections IV.E and V.D of this preamble. Also, the Panel Report includes all 

comments received from SERs (Appendix B of the Report) and summaries of the two 

outreach meetings that were held with the SERs. In accordance with the RFA/ SBREFA 

requirements, the Panel evaluated the aforementioned materials and SER comments on 

issues related to the IRFA. The Panel’s recommendations from the Final Panel Report 

are discussed below.

It should be noted that during the Panel process, two additional issues were 

discussed with SERs that were under consideration by the Agency for the Tier 3 

proposal. As noted in Section IV.D.5, 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 inuse gasoline. Neither of these issues is being proposed in today’s notice. Therefore, the 

following discussion of the Panel recommendations does not address these issues. The 
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reader is directed to the Panel Report, located in the rulemaking docket, for more 

information on both of these issues.

c. Panel Recommendations

i. Tier 3 Fuels

The Panel discussed several regulatory flexibility alternatives with SERs for small 

businesses in the gasoline production and distribution, fuel additive manufacturing, and 

ethanol production industries subject to the proposed fuel requirements. Panel 

recommendations on these approaches are discussed below.

(1) Lead Time—Sulfur

The Panel recommended that EPA propose a delay option, similar to previous 

fuels rulemakings, in the Tier 3 proposed rule. The Panel recommended that EPA allow 

small refiners to postpone their compliance with the Tier 3 program for up to three years. 

Small refiners choosing this flexibility option would 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 sulfur 

standard would begin on January 1, 2020. Any small refiner choosing this proposed 

option would be allowed to continue use of their Tier 2 gasoline sulfur credits through 

December 31, 2019 to meet the refiner average 30-ppm sulfur standard.

The Panel also recommended that EPA request comment on case-by-case 

hardship provisions that would provide additional relief for any refiner experiencing 

extreme difficulty in compliance with the Tier 3 requirements, as discussed below in 

Section XII.C.6.c.i.(6).

(2) Provisions for Additive Manufacturers

The Panel recommended that EPA provide flexibilities for gasoline additive 

manufacturers. Following discussion with EPA, the Panel suggested that EPA propose 

the following flexibilities:

 For additives used downstream of the refiner: Differentiating bulk additives 

based on whether they meet a 20- or 25-ppm sulfur standard.

 For aftermarket consumer additives: Allow for aftermarket additives to meet 

either a 20-ppm or 25-ppm sulfur cap.

 For additives not meeting a 10-, 20-, or 25-ppm sulfur limit: Allow for the use 

of volume accounting reconciliation (VAR) records for additives that would 

not be able to meet a 25-ppm sulfur cap to show that use of the additive would 

not cause the sulfur level of the finished fuel to exceed 10 ppm (similar to the 

Nonroad Diesel Rulemaking, 69 FR 39088, June 29, 2004), and require 

product labeling for aftermarket additives.
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(3) Refinery Gate and Downstream Caps

With regard to the 20-ppm refinery gate cap discussed in Section 3 of the Panel 

Report, the Panel had concerns that such a standard could cause operational problems for 

small refiners during a refinery turnaround or an upset, because a cap of this level could 

result in a refiner not being able to produce gasoline (as noted in their comments in 

Section 8 of the Panel Report). The Panel likewise had 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 

(also noted in their comments in Section 8 of the Panel Report).

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. Thus, the SBA and OMB Panel members recommend that EPA 

propose retaining the 80-ppm and 95-ppm caps.

The Panel also recommended that EPA request comment on additional refinery

gate and downstream caps above 20/25 ppm but below 80/95 ppm. Additionally, the 

Panel recommended that EPA allow the current Tier 2 80-ppm sulfur refinery gate cap 

and 95-ppm sulfur downstream cap in Alaska to remain at these levels indefinitely.

(4) Hardship Provisions

During the Panel process, EPA stated its intent to 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. A hardship based on extreme unforeseen circumstances is intended to provide 

short term relief due to unanticipated circumstances beyond the control of the refiner, 

such as a natural disaster or a refinery fire. An extreme hardship is intended to provide 

short-term relief based on extreme circumstances (e.g., extreme financial problems, 

extreme operational or technical problems, etc.) that impose extreme hardship and thus 

significantly affect a refiner's ability to comply with the program requirements by the 

applicable dates. In the context of the proposal, the Panel agrees that such relief could 

consider long-term relief on the sulfur cap (similar to that for Alaska) if the 

circumstances both warrant it and can be structured in a way to allow for it. The Panel 

agrees with the proposal of such provisions and recommended that EPA include them in 

the Tier 3 proposed rulemaking.

ii. Tier 3 Vehicles

As discussed in Section 5 of the Panel Report, in addition to vehicle 

manufacturers, two distinct categories of businesses relating to highway light-duty

vehicles and heavy-duty trucks would be 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 
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categories as well as any businesses in these categories 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 discussed several regulatory flexibility alternatives with SERs for small 

businesses that certify vehicles subject to the proposed Tier 3 emission standards. As 

described in Appendix A (and similar to provisions in the Tier 2 rule), EPA sought 

comment from the SERs on allowing small entities to simply comply with the proposed 

emission standards with 100 percent of their vehicles during the last year of the phase-in 

period. In addition, EPA sought comment on the following flexibilities: (1) a hardship 

provision that would allow these businesses to apply for additional time to meet any of 

the 100 percent phase-in 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 (see 40 CFR 86.1845-04). 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 

emission testing requirements.

Panel recommendations on these approaches are discussed below.

(1) Exhaust Emission Standards and Lead time

In the types of businesses subject to the potential Tier 3 standards, small 

businesses have limited resources available for developing new designs to comply with 

new emission standards. In addition, it is often necessary for these businesses to rely on 

vendor companies for technology. Moreover, percentage phase-in requirements pose a 

dilemma for a small manufacturer that has a limited product line (e.g., the manufacturer 

certifies vehicles in only one or two test groups). Thus, similar to the flexibility

provisions implemented in previous vehicle rules, the Panel recommended that EPA 

allow small businesses the following flexibility options for meeting the potential Tier 3 

exhaust emissions standards.

The Panel recommended that small businesses be given additional lead time to 

comply with the potential Tier 3 exhaust standards and allow small businesses to comply

with the standards with 100 percent of their vehicles starting in model year 2022. (This is 

similar to the Tier 2 rule where EPA allowed small manufacturers to wait until the end of 

the phase-in to comply with the Tier 2 standards.) During the Panel process, the 

proposed Tier 3 rule was expected to have several different phase-in schedules; with the 

final dates varying from model year 2021 for the new exhaust PM standards and use of 

the new E15 certification fuel, to model year 2022 for the new evaporative emission 

standards, to model year 2025 for the new exhaust gaseous pollutant standards. The 

Panel noted that requiring all small businesses to comply with the full slate of Tier 3 

requirements in model year 2022 should provide sufficient lead time for manufacturers to 

plan for and implement the technology changes needed to comply with the Tier 3 

standards.
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One of the SERs recommended that EPA adopt relaxed exhaust standards for 

small manufacturers. The SER noted that the exhaust emission averaging program being 

proposed by EPA would allow large manufacturers that have many engine families to 

certify their small, niche products at levels numerically higher than the standards. Small 

manufacturers that typically do not have more than one or two emission families 

generally cannot use averaging to the same extent because of their limited product 

offerings. The SER’s concern was that the high-performance vehicles produced by large 

manufacturers which they compete against would be able to certify at numerically higher 

levels at less cost than the SER would incur. While EPA was planning to propose the 

same standards for all manufacturers, the Panel recommended that EPA request comment 

on allowing small manufacturers to meet relaxed exhaust emission standards. This could 

also be included as part of the hardship provision discussed below. The Panel 

recommended that EPA request comment on the relaxed standards recommended by the 

SER. The SER-recommended relaxed NMOG+NOX standards over the Federal Test 

Procedure (FTP) are 0.125 grams/mile in model year 2020 and 0.070 grams/mile in 

model year 2025. In addition, the Supplemental FTP standards would be the standards 

for the corresponding bins which the manufacturer selected for complying with the FTP 

standards. For example, if the manufacturer certified to the proposed Tier 3 Bin 125 

standards over the FTP, the manufacturer would have to comply with the corresponding 

Tier 3 Bin 125 standards for the Supplemental FTP.

(2) Evaporative Emission Standards and Lead time

The Panel recommended that small businesses comply with the Tier 3 evaporative 

emission standards, including the leak standard, with 100 percent of their vehicles 

starting in model year 2022. For evaporative emissions, where the Tier 3 standards could 

begin as early as 2017 and phase-in through 2022, this provision would allow small 

businesses and SVMs to wait until the last year of the Tier 3 phase-in period for 

evaporative emission standards for all of their vehicles. This start date is consistent with 

the start date described above for the Tier 3 exhaust emission requirements being 

recommended by the Panel for small businesses.

(3) Assigned Deterioration Factors

Under EPA’s regulations, manufacturers must demonstrate that their vehicles 

comply with the emission standards throughout the “useful life” period. This is generally

done by testing vehicles at low-mileage and then applying a deterioration factor to these 

emission levels. The deterioration factors are determined by aging new emission control 

systems and then testing the aged systems again to determine how much deterioration in 

emissions has occurred. In order to reduce the testing burden on small manufacturers, 

EPA suggested that small manufacturers could use deterioration factor values assigned by

EPA instead of performing the extended testing. A manufacturer would apply the 

assigned deterioration factors to its low-mileage emission level to demonstrate whether it 

complied with the Tier 3 emission standards. EPA currently allows this flexibility for 

small manufacturers. The Panel recommended that EPA propose that small businesses be 

allowed the option to use EPA-developed assigned deterioration factors in demonstrating 

compliance with the Tier 3 exhaust and evaporative emission standards. In the past, EPA 
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has relied on deterioration factor data from large manufacturers to develop the assigned 

DFs for small manufacturers. EPA would expect to follow a similar procedure to 

determine the assigned DFs for the Tier 3 standards once large manufacturers start 

certifying their Tier 3 designs. Given that larger manufacturers would begin phasing in 

to the Tier 3 standards in model year 2017, EPA should have a significant set of 

emissions deterioration data upon which to base the assigned DFs for small businesses 

within the first few years of the Tier 3 program. EPA recognizes that assigned DFs need 

to be determined well in advance of model year 2022 in order to provide sufficient time 

for small businesses to decide whether or not to use the assigned DFs for certification 

purposes.

(4) Reduced Testing Burden

Under EPA’s regulations, manufacturers must perform in-use testing on their 

vehicles and demonstrate their in-use vehicles comply with the emission standards. The 

current in-use testing regulations provide for reduced levels of testing for small 

manufacturers, including no testing in some cases. EPA suggested that these provisions 

should continue for small manufacturers with the Tier 3 program. The Panel 

recommended that EPA propose that small businesses be allowed to have reduced burden 

under the in-use testing program for Tier 3 vehicles.

One SER requested that EPA eliminate some of the evaporative emission testing 

requirements for small businesses based on its belief that some of the tests may be 

duplicative. While EPA noted (during the Panel process) that it understood the reasons 

behind the manufacturer’s suggestion, EPA believed it may be premature to consider 

such an option in the Tier 3 rule given the impact of the CO2 emission standards on 

engine and fuel system development. Currently, it is generally understood that the 2-day

diurnal test drives the purge characteristics of evaporative control systems, while the 

refueling test, and to a lesser degree the 3-day test, drive the capacity requirement of 

evaporative canisters. Prospectively, due to expected changes in engine and fuel system 

designs in response to upcoming CO2 emission standard requirements, this may not be 

the case. Therefore, at the time of the Panel process, EPA noted its belief that it is 

appropriate to retain all of the evaporative test procedures. It can be noted that under 

current regulations, EPA does allow manufacturers to waive 2-day diurnal testing for 

certification purposes (see 40 CFR 86.1829-01(b)(2)(iii)) and perform only the 2-day

diurnal test as part of the in-use testing program (see 40 CFR 86.1845-04(c)(5)(ii)). 

These provisions would continue in the Tier 3 program. In general, EPA noted that it is 

open to changes that reduce test burden while maintaining the environmental 

effectiveness of its programs and could consider changes like those suggested by the SER 

in the future as the impacts of the future regulations on engine and vehicle design become 

clearer. EPA also stated that it intends to request comment in the Tier 3 proposal on 

streamlining the current test procedures for small businesses in ways that would still 

maintain the overall stringency of the tests.

(5) Hardship Provisions
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The Panel recommended that hardship provisions be provided to small businesses 

for the Tier 3 exhaust and evaporative emission standards. Under the hardship 

provisions, small businesses would be allowed to apply for additional time to meet the 

100 percent phase-in requirements for exhaust and evaporative emissions. All hardship 

requests would be subject to EPA review and approval. Appeals for such hardship relief 

would be required to be made in writing and submitted well before the earliest date of 

noncompliance. The request should identify how much time is being requested. It must 

also include evidence that the noncompliance would occur despite the manufacturer's best 

efforts to comply, and must contain evidence that severe economic hardship would be 

faced by the company if the relief is not granted. The above provision should effectively

provide the opportunity for small businesses to obtain more time to comply with the new 

Tier 3 standards. (The existing hardship provisions limit the extra time that can be 

requested to 1 year, but such a limit may or may not be included in the proposed Tier 3 

hardship provisions.)

(6) Applicability

Under EPA’s current Tier 2 regulations, EPA provides a number of flexibilities 

for small volume manufacturers. The criteria for determining if a company is a small 

volume manufacturer is based on the annual production level of vehicles and is based on 

whether the company produces less than 15,000 vehicles per year. Unlike EPA’s small 

volume manufacturer criteria noted above, SBA defines which manufacturers are small 

businesses (and therefore should be considered under the SBAR Panel process) based on 

the number of employees for vehicle manufacturers and annual revenues for ICIs and 

alternative fuel converters. For example, SBA defines small business vehicle 

manufacturers as those who have less than 1,000 employees. Similarly, SBA defines 

small business ICIs as those who have annual revenues of less than $8 million per year.

The Panel recommended that EPA propose to allow all small businesses that meet 

the SBA criteria be eligible for the flexibilities described above. In addition, in the Panel 

Report, EPA stated that it is expecting to propose that manufacturers that meet a specified 

sales-based criterion to be eligible for the flexibilities described above. It is relatively 

easy for a manufacturer to project and ultimately determine sales. Determining the 

annual revenues or number of employees is less straightforward. In the recent rule 

setting the first light-duty vehicle and truck CO2 emission standards, EPA adopted 

provisions for small manufacturers based on a sales cutoff of 5,000 vehicles per year as 

opposed to the 15,000 level noted earlier that is used in the Tier 2 program. In the Panel 

Report, EPA noted that it expects to propose a small volume manufacturer definition 

based on the 5,000 vehicle per year level for the Tier 3 program. EPA believes the 5,000 

unit cut-off for small volume manufacturers would include all of the small business 

vehicle manufacturers, ICIs, and alternative fuel converters that meet the applicable SBA 

definition as well as some additional companies that have similar concerns to small 

businesses. Lastly, EPA noted in the Panel Report that it expects to propose the 

flexibilities described above to be available to any manufacturer that meets either the 

SBA small business criteria or the sales-based criteria.
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EPA invites comment on all aspects of the proposal and its impacts on small 

entities.

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. Under section 202 of the UMRA, EPA generally must prepare a written 

statement, including a cost-benefit analysis, for proposed and final rules with ‘‘Federal 

mandates’’ that may result in expenditures to State, local, and tribal governments, in the 

aggregate, or to the private sector, of $100 million or more in any one year. Accordingly, 

EPA has prepared a statement of the cost-benefit analysis as required by section 202 of 

the UMRA; this statement can be found in Sections VII and VIII of this preamble, and in 

Chapter 8 of the draft RIA. Before promulgating an EPA rule for which a written 

statement is needed, section 205 of the UMRA generally requires EPA to identify and 

consider a reasonable number of regulatory alternatives and adopt the least costly, most 

cost-effective or least burdensome alternative that achieves the objectives of the rule. 

The provisions of section 205 do not apply when they are inconsistent with applicable 

law. Moreover, section 205 allows EPA to adopt an alternative other than the least 

costly, most cost-effective or least burdensome alternative if the Administrator publishes 

with the final rule an explanation why that alternative was not adopted.

Before EPA establishes any regulatory requirements that may significantly or 

uniquely affect small governments, including tribal governments, it must have developed 

under section 203 of the UMRA a small government agency plan. The plan must provide 

for notifying potentially affected small governments, enabling officials of affected small 

governments to have meaningful and timely input in the development of EPA regulatory

proposals with significant Federal intergovernmental mandates, and informing, 

educating, and advising small governments on compliance with the regulatory

requirements. 

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 

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 

proposal 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 proposal 

represents the least costly, and most cost-effective approach to achieve the statutory

requirements of the rule. The costs and benefits associated with the proposal are 
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discussed above in Sections VII and VIII of this preamble, and in Chapter 8 of the draft 

RIA, as required by section 202 of the UMRA.

E. Executive Order 13132: Federalism

This proposed action does not have federalism implications. It would 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 proposed rule, EPA did consult with representatives of various State and 

local governments in developing this rule. EPA has 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 ground-level 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 solicits 

comment on this proposed action from State and local officials.

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 proposed rule would be implemented at 

the Federal level and would impose compliance costs only on those in the gasoline 

production, distribution, and additive industry and in the highway and nonroad engine, 

vehicle, and equipment industries. Tribal governments would 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.

Although Executive Order 13175 does not apply to this action, EPA specifically

solicits additional comment on this proposed action from tribal officials.

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 proposed standards on children. 

The results of this evaluation are contained in Section II.B and associated references.
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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.527 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.528

Certain motor vehicle emissions present greater risks to children as well. For 

example, mutagenic carcinogens such as benzene and 1,3-butadiene have a larger impact 

during young life stages, given the rapid development of the corporal systems.529 

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 

for NO2, PM, ozone and CO, describe children as a group with greater susceptibility. 

Section II.B.5 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 nearroadway environment as one containing numerous exposures potentially associated with 

adverse health effects.

In addition to their underlying biological susceptibility, as discussed in Section 

II.B.1, children may be more vulnerable to the effects of air pollution because of their 

high levels of outdoor activity. As discussed in that section, greater impacts of ozone 

have been reported among children who are more active outdoors.

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 

 

527 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.

528 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.

529 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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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.

The public is invited to submit comments or identify peer-reviewed studies and 

data that assess effects of early life exposure to the air pollutants affected by the proposed 

standards. 

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 proposed 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 proposal’s potential effects on energy supply, distribution, or use have been 

analyzed and are further discussed above in:

 Section V—fuel provisions of the proposed rule and flexibilities, including 

hardship provisions.

 Section V.2.c—discussion on proposed refinery lead time.

 Section X—proposed economic impacts (specifically, Section X.C for fuel 

economic impacts, and Section X.D on employment impacts).

 Section VII.B—estimated costs of the proposed fuel program.

Given the estimated costs and impacts of the proposed rule, as discussed in these 

areas of this preamble, we do not expect this rule to have any adverse effect on the supply

or distribution of gasoline. 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 
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of emissions, considering cost-benefit analyses, given by the reduction in sulfur being 

proposed 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 proposed rulemaking involves technical standards. EPA is proposing to 

update a number of regulations which already contain voluntary consensus standards to 

more recent versions of these standards. EPA is proposing to use 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.

This proposed rulemaking also involves environmental monitoring or 

measurement. Consistent with the Agency’s Performance Based Measurement System 

(“PBMS”), EPA proposes not to require the use of specific, prescribed analytic methods. 

Rather, the Agency plans to allow the use of any method that meets the prescribed 

performance criteria. The PBMS approach is intended to be more flexible and costeffective 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.

Table XII-1 Designated Analytical Test Methods for Gasoline and Diesel Fuel

Fuel Parameter Designated Analytical Method

Sulfur in gasoline ASTM D 2622-05

Sulfur in butane ASTM D 6667-01

500 ppm Sulfur Diesel Fuel ASTM D 2622-05

Olefins in gasoline ASTM 1319-03ε1

Reid vapor pressure (RVP) in gasoline ASTM D 5191-07, 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 D86-07b
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Benzene in gasoline ASTM D 3606-07, except that instrument 

parameters shall be adjusted to ensure complete 

resolution of benzene, ethanol, and methanol 

peaks.

Aromatics in gasoline ASTM D 5769-04, except that sample chilling 

requirements in section 8 of this standard are 

optional.

Oxygen and oxygenate content in 

gasoline

ASTM D 5599-00(2005)

Aromatics in diesel fuel ASTM D1319-03 ε1

EPA welcomes comments on this aspect of the proposed rulemaking and, 

specifically, invites the public to identify potentially-applicable voluntary consensus 

standards and to explain why such standards should be used in this regulation.

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 

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 proposed rule would 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 proposed rule would reduce emissions from all 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 or earlier). As such, this proposal would increase the level of environmental 

protection for all populations. As discussed in Section III.B.7, there is evidence that 

minority populations and low-income populations live disproportionately near hightraffic roadways, where concentrations of many air pollutants are elevated. We expect 

this proposed rule to increase the level of environmental protection for these populations.

Thus, this proposed rule would not have a disproportionately high adverse human 

health or environmental effect on minority or low-income populations.
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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

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, Incorporation by reference, 

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
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Administrative practice and procedure, Air pollution control, Confidential 

business information, Environmental protection, Incorporation by reference, Labeling, 

Motor vehicle pollution, 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.
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For the reasons set forth in the preamble, part 79 of title 40, chapter 1 of the Code of 

Federal Regulations is proposed to be amended as follows:

Part 79-REGISTRATION OF FUEL AND FUEL ADDITIVES

1. The authority citation for part 79 continues to read as follows:

Authority: 42 USC 7414, 7524, 7545, and 7601

2. Section 79.5 is amended by:

a. Revising paragraph (a).

b. Revising the paragraph (b) introductory text.

§ 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, 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 Table 1 to §79.5 on forms supplied by the Administrator upon 

request.

Table 1 to §79.5: Quarterly Reporting Deadlines

Calendar Quarter Time Period Covered Quarterly Report Deadline

Quarter One January 1 – March 31 June 1

Quarter Two April 1 – June 30 September 1

Quarter Three July 1 – September 30 December 1

Quarter Four 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 paragraphs (c) and (d) of this 

section in the designation of the fuel in subpart D. 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 40 CFR part 80 subpart D, 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 

paragraphs (c) and (d) of this section in the designation of the additive in 40 CFR part 80 subpart 

D. Additive manufacturers shall also report annually the volume of each additive produced. 

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 additive in 40 CFR part 

80 subpart D, 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:
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* * * * *

For the reasons set forth in the preamble, part 80 of title 40, chapter 1 of the Code of 

Federal Regulations is amended as follows:

Part 80-REGULATION OF FUEL AND FUEL ADDITIVES

3. The authority citation for part 80 is revised to read as follows:

Authority: 42 U.S.C., 7414, 7521(l), 7545, and 7601(a).

4. Section 80.2 is amended by:

a. Revising paragraph (d).

b. Revising paragraph (w).

c. Revising paragraph (z).

d. Adding paragraphs (vvv), (www), (xxx), (yyy), (zzz), and (aaaa).

§ 80.2 Definitions.

* * * * *

(d) Previously certified gasoline, or PCG, means gasoline, RBOB or CBOB that 

previously has been included in a batch of gasoline 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 

International standard method D976-06(2011), entitled, “Standard Test Method for Calculated 

Cetane Index of Distillate Fuels”, approved October 1, 2011. ASTM International test method 

D976-06(2011) is incorporated by reference. This incorporation by reference was approved by 

the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. 

Copies may be obtained from ASTM International, 100 Barr Harbor Dr., West Conshohocken, 

PA 19428-2959. Copies may be inspected at the Air Docket, EPA/DC, EPA West, Room B102, 

1301 Constitution Ave., NW, Washington, D.C., or 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.

* * * * *

(z) Aromatic content is the aromatic hydrocarbon content in volume percent as 

determined by ASTM International standard test method D1319-10, entitled, “Standard Test 

Method for Hydrocarbon Types in Liquid Petroleum Products by Fluorescent Indicator 

Adsorption”, approved May 1, 2010. ASTM International test method D1319-10 is incorporated 

by reference. This incorporation by reference was approved by the Director of the Federal 

Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from 
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ASTM International, 100 Barr Harbor Dr., West Conshohocken, PA 19428-2959. Copies may

be inspected at the Air Docket, EPA/DC, EPA West, Room B102, 1301 Constitution Ave., NW, 

Washington, D.C., or 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.

* * * * *

(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 used as an additive 

in gasoline, and that meets the requirements of §80.1610.

(www) Oxygenate manufacturer means any person who owns, leases, operates, controls, 

or supervises an oxygenate production facility.

(xxx) Oxygenate production facility means any facility where oxygenate is produced.

(yyy) CBOB means gasoline blendstock that becomes conventional gasoline solely upon 

the addition of oxygenate.

(zzz) 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 a natural gas production facility, in a gas processing plant, or in a natural gas pipeline. NGL is 

sometimes also referred to as “natural gasoline”.

(aaaa) 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.

5. Section 80.8 is revised to read as follows:

§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 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 International (ASTM) standard 

practice D4057 (incorporated by reference, see paragraph (e) of this section). 

(b) Automatic sampling. Automatic sampling of petroleum products in pipelines shall be 

performed according to the applicable procedures specified in ASTM International (ASTM) 

standard practice D4177 (incorporated by reference, see paragraph (e) of this section).

(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 
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procedures in ASTM standard practice D5842 (incorporated by reference, see paragraph (e) of 

this section).

(d) Sample compositing. Composite samples shall be prepared using the applicable 

procedures in ASTM standard practice D5854 (incorporated by reference, see paragraph (e) of 

this section).

(e) Materials incorporated by reference. The Director of the Federal Register approved 

the incorporation by reference of the documents listed in this section as prescribed in 5 U.S.C. 

552(a) and 1 CFR part 51. Anyone may inspect copies at the U.S. EPA, Air and Radiation 

Docket and Information Center, 1301 Constitution Ave., N.W., Room B102, EPA West 

Building, Washington, DC, 20460, under EPA docket ID Number EPA–HQ–OAR–2011–0135, 

or at the National Archives and Records Administration (NARA). The telephone number for the 

Air Docket Public Reading Room is (202) 566-1742. 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. For 

further information on these test methods, please contact the Environmental Protection Agency

at 734-214-4582.

(1) ASTM International material. Anyone may purchase copies of these materials from 

the ASTM International, 100 Barr Harbor Dr., West Conshohocken, PA 19428-2959, or by 

contacting ASTM International customer service at 10-832-9585, or by contacting the email 

address of service@astm.org from the ASTM International Web site of http://www.astm.org.

(i) ASTM International standard practice D4057-06 (Reapproved 2011) (“ASTM 

International D4057”), Standard practice for Manual Sampling of Petroleum and Petroleum 

Products, approved June 1, 2011.

(ii) ASTM International standard practice D4177-95 (Reapproved 2010) (“ASTM 

International D4177”), Standard Practice for Automatic Sampling of Petroleum and Petroleum 

Products, approved May 1, 2010.

(iii) ASTM International standard practice D5842-04 (Reapproved 2009) (“ASTM 

International D5842”), Standard Practice for Sampling and Handling of Fuels for Volatility

Measurement, approved June 1, 2009.

(iv) ASTM International standard practice D5854-96 (Reapproved 2010) (“ASTM 

International D5854”), Standard Practice for Mixing and Handling of Liquid Samples of 

Petroleum and Petroleum Products, approved May 1, 2010.

(2) [Reserved]

6. A new section 80.10 is added to subpart A to read as follows:

§ 80.10 Correction of batch volume reports.
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For purposes of compliance with the reporting requirements of this part, parties required 

to submit batch reports are not required to correct unintentional errors in reporting batch volume 

on previously submitted batch reports where all of the following circumstances apply:

(a) The reporting violation pertains solely to the volume of the batch.

(b) The volume of the batch is incorrect by no more than 500 gallons or by no more than 

1 percent of the true batch volume, in gallons, whichever value (in gallons) is less.

(c) Reporting the true volumes of all the batches for the reporting period would not result 

in a higher annual average sulfur or benzene value than reported using the incorrect values after 

rounding to the applicable digit for reporting.

(d) Reporting the true value for any batch would not result in a reduced number of 

gallons for a violation of any per-gallon standard or a violation of any other requirement of the 

Clean Air Act.

(e) The reporting party certifies that the conditions in paragraphs (a) through (d) of this 

section have been met.

(f) For subpart M of this part, this section applies only to the volume of fuels produced or 

exported that result in a renewable volume obligation under subpart M of this part for obligated 

parties.

7. Section 80.46 is amended by:

a. Revising paragraphs (a)(1), (a)(2), (a)(3), and (a)(4).

b. Revising paragraphs (b)(1) and (b)(2)(i) introductory text.

c. Revising paragraph (c).

d. Revising paragraph (d).

e. Revising paragraphs (e)(1) and (e)(2), and adding a new paragraph (e)(3).

f. Revising paragraphs (f)(1) and (f)(3)(i).

g. Revising paragraphs (g)(1) and (g)(2)(i).

h. Revising paragraph (h) introductory text and paragraph (h)(1).

§80.46 Measurement of reformulated gasoline and conventional gasoline fuel parameters.

(a) * * *

(1) Through November 29, 2014, the sulfur content of gasoline must be determined by 

ASTM International standard method D2622 (incorporated by reference, see paragraph (h) of 

this section) or by one of the alternative test methods specified in paragraph (a)(3) of this section. 

Beginning November 30, 2014, the sulfur content of gasoline must be determined by a test 

method approved under §80.47.
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(2) Through November 29, 2014, the sulfur content of butane must be determined by

ASTM International standard method D6667 (incorporated by reference, see paragraph (h) of 

this section) or by one of the alternative test methods specified in paragraph (a)(4) of this section. 

(3) Through November 29, 2014, any refiner or importer may use any of the following 

methods 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:

(i) ASTM International standard test method D5453 (incorporated by reference, see 

paragraph (h) of this section).

(ii) ASTM International standard test method D6920 (incorporated by reference, see 

paragraph (h) of this section).

(iii) ASTM International standard test method D3120 (incorporated by reference, see 

paragraph (h) of this section).

(iv) ASTM International standard test method D7039 (incorporated by reference, see 

paragraph (h) of this section).

(4) Beginning November 30, 2014, the sulfur content of butane must be determined by a 

test method approved under §80.47. Through November 29, 2014, any refiner or importer may

determine the sulfur content of butane using any one of the following methods; provided the 

refiner or importer test result is correlated with the method specified in paragraph (a)(2) of this 

section:

(i) ASTM International standard method D4468 (incorporated by reference, see 

paragraph (h) of this section).

(ii) ASTM International standard method D3246 (incorporated by reference, see 

paragraph (h) of this section).

(b) * * *

(1) Through November 29, 2014, olefin content must be determined using ASTM 

International standard method D1319 (incorporated by reference, see paragraph (h) of this 

section). Beginning November 30, 2014, the olefin content of gasoline may be determined by a 

test method approved under §80.47.

(2)(i) Through November 29, 2014, any refiner or importer may determine olefin content 

using ASTM International standard method ASTM D6550 (incorporated by reference, see 

paragraph (h) of this section) for purposes of meeting any testing requirements involving olefin 

content, provided that:

* * * * *
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(c) Reid Vapor Pressure (RVP). Through November 29, 2014, Reid Vapor Pressure must 

be determined using ASTM International standard method D5191 (incorporated by reference, see 

paragraph (h) of this section), 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.

Beginning November 30, 2014, RVP may be determined by a test method approved under 

§80.47.

(d) Distillation. Through November 29, 2014, distillation parameters must be determined 

using ASTM International standard method D86 ((incorporated by reference, see paragraph (h) 

of this section). Beginning November 30, 2014, the distillation parameters may be determined 

by a test method approved under §80.47.

(e) * * *

(1) Through November 29, 2014, benzene content must be determined using ASTM 

International standard method D3606 (incorporated by reference, see paragraph (h) of this 

section), except that:

(2) 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 

International D3606 (incorporated by reference, see paragraph (h) of this section) when present.

(3) Beginning November 30, 2014, the benzene content may be determined by a test 

method approved under §80.47.

(f)(1) Through November 29, 2014, aromatic content must be determined using ASTM 

International standard method D5769 (incorporated by reference, see paragraph (h) of this 

section), except the sample chilling requirements in section 8 of this standard method are 

optional. Beginning November 30, 2014, the aromatic content may be determined by a test 

method approved under §80.47.

(2) * * *

(3) (i) Through November 29, 2014 any refiner or importer may determine aromatics 

content using ASTM International standard method D1319 (incorporated by reference, see 

paragraph (h) of this section) for the purposes of meeting any test requirement involving 

aromatic content; provided that:

* * * * *

(g) * * *
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(1) Through November 29, 2014, oxygen and oxygenate content must be determined 

using ASTM International standard method D5599 (incorporated by reference, see paragraph (h) 

of this section). Beginning November 30, 2014, oxygen and oxygenate content may be 

determined by a test method approved under §80.47.

(2)(i) Through November 29, 2014, 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 International 

standard method D4815 (incorporated by reference, see paragraph (h) of this section) for 

purposes of meeting any testing requirement; provided that:

* * * * *

(h) Materials incorporated by reference. The Director of the Federal Register approved 

the incorporation by reference of the documents listed in this section as prescribed in 5 U.S.C. 

552(a) and 1 CFR 51. Anyone may inspect copies at the U.S. EPA, Air and Radiation Docket 

and Information Center, 1301 Constitution Ave., N.W., Room B102, EPA West Building, 

Washington, DC, 20460, under EPA docket ID Number EPA–HQ–OAR–2011–0135, or at the 

National Archives and Records Administration (NARA). The telephone number for the Air 

Docket Public Reading Room is (202) 566-1742. 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. For 

further information on these test methods, please contact the Environmental Protection Agency

at 734-214-4582.

(1) ASTM International material. Anyone may purchase copies of these materials from 

the ASTM International, 100 Barr Harbor Dr., West Conshohocken, PA 19428-2959, or by 

contacting ASTM International customer service at 10-832-9585, or by contacting the email 

address of service@astm.org from the ASTM International Web site of http://www.astm.org.

(i) ASTM International standard method D3606-10 (“ASTM International D3606”), 

“Standard Test Method for Determination of Benzene and Toluene in Finished Motor and 

Aviation Gasoline by Gas Chromatography, approved October 1, 2010.

(ii) ASTM International standard method D1319-10 (“ASTM International D1319”), 

“Standard Test Method for Hydrocarbon Types in Liquid Petroleum Products by Fluorescent 

Indicator Absorption”, approved May 1, 2010.

(iii) ASTM International standard method D6550-10 (“ASTM International D6550”), 

“Standard Test Method for the Determination of Olefin Content of Gasolines by SupercriticalFluid Chromatography”, approved October 1, 2010.

(iv) ASTM International standard method D4815-09 (“ASTM International D4815”), 

“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, 2009.
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(v) ASTM International standard method D2622-10 (“ASTM International D2622”), 

“Standard Test Method for Sulfur in Petroleum Products by Wavelength Dispersive X-Ray

Fluorescence Spectrometry”, approved February 15, 2010.

(vi) ASTM International standard method D2622-10 (“ASTM International D2622”), 

“Standard Test Method for Sulfur in Petroleum Products by Wavelength Dispersive X-Ray

Fluorescence Spectrometry”, approved February 15, 2010.

(vii) ASTM International standard method D3246-11 (“ASTM International D3246”), 

“Standard Test Method for Sulfur in Petroleum Gas by Oxidative Microcoulometry”, approved 

June 1, 2011.

(viii) ASTM International standard method D5599-00(2010) (“ASTM International 

D5599”), “Standard Test Method for Determination of Oxygenates in Gasoline by Gas 

Chromatography and Oxygen Selective Flame Ionization Detection”, approved October 1, 2010.

(ix) ASTM International standard method D5769-10 (“ASTM International D5769”), 

“Standard Test Method for Determination of Oxygenates in Gasoline by Gas Chromatography 

and Oxygen Selective Flame Ionization Detection”, approved October 1, 2010.

(x) ASTM International standard method D86-11a (“ASTM International D86”), 

“Standard Test Method for Determination of Petroleum Products at Atmospheric Pressure”, 

approved July 1, 2011.

(xi) ASTM International standard method D5453-09 (“ASTM International D5453”), 

“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 June 

15, 2009.

(xii) ASTM International standard method D6920–07 (“ASTM D6920”), Standard Test 

Method for Total Sulfur in Naphthas, Distillates, Reformulated Gasolines, Diesels, Biodiesels, 

and Motor Fuels by Oxidative Combustion and Electrochemical Detection, approved December 

1, 2007.

(xiii) ASTM International standard method D3120-08 (“ASTM International D3120”), 

“Standard Test Method for Trace Quantities of Sulfur in Light Petroleum Hydrocarbons by

Oxidative Microcoulometry”, approved December 15, 2008.

(xiv) ASTM International standard method D7039–07 (“ASTM D7039”), Standard Test 

Method for Sulfur in Gasoline and Diesel Fuel by Monochromatic Wavelength Dispersive X-ray

Fluorescence Spectrometry, approved May 1, 2007.

(xv) ASTM International standard method D6667-10 (“ASTM International D6667”), 

“Standard Test Method for Determination of Total Volatile Sulfur in Gaseous Hydrocarbons and

Liquefied Petroleum Gases by Ultraviolet Fluorescence”, approved October 1, 2010.
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(xvi) ASTM International standard method D4468-85(2006) (“ASTM International 

D4468”), “Standard Test Method for Total Sulfur in Gaseous Fuels by Hydrogenolysis and 

Rateometric Colorimetry”, approved June 1, 2006.

* * * * *

8. Section 80.47 is revised 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: 

(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, 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. 

(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.
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(8) Method-defined fuel parameter means a fuel parameter for which an EPA-prescribed 

primary test method or designated method defines the regulatory standard. Examples of methoddefined 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 

International standard practice D6708 (incorporated by reference, see paragraph (r) of this 

section). 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 VCSB and non-VCSB regulated parties. 

(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).

(13) Non-Voluntary consensus-based standards body (non-VCSB) means a domestic or 

international regulated party who 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 November 30, 2014, for motor vehicle gasoline 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 (7 or fewer tests per week and 2 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 D7039-07 (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 
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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 November 30, 2014, for motor vehicle gasoline 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 May 30, 2014 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 November 30, 2014, 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 (7 or fewer tests per 

week and 2 or fewer tests per day) on samples using good laboratory practices taken from 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 D6667-10 

(Example: A 10 ppm sulfur butane sample: maximum allowable standard deviation of 20 

tests≤1.5*(1.15ppm/2.77)=0.62 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 November 30, 2014, for butane subject to the butane sulfur 

standard at §§80.82 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 ARV of the standard by more than 0.47 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 0.94 ppm sulfur; and
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(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 May 30, 2014 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 November 30, 2014, for motor vehicle gasoline 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 (7 or fewer 

tests per week and 2 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 

D1319-10 (Example: A gasoline containing 9Vol% olefins: maximum allowable standard 

deviation of 20 tests≤1.5*(0.972Vol%/2.77)=0.53Vol%). 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 May 30, 2014 is exempt 

from the requirements of paragraph (d)(1) of this section.

(e) Precision criteria for approval of the method defined fuel parameter of aromatics in 

gasoline.

(1) Precision. Beginning November 30, 2014, for motor vehicle gasoline 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 (7 or fewer 

tests per week and 2 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 

D1319-10 (Example: A gasoline containing 32Vol% aromatics: maximum allowable standard 

deviation of 20 tests≤1.5*(1.3Vol%/2.77)=0.70Vol%). 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 May 30, 2014 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.
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(1) Precision. Beginning November 30, 2014, for motor vehicle gasoline 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 (7 or fewer 

tests per week and 2 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 

5599-00(2010) (Example: A gasoline containing 3Mass% total oxygen: maximum allowable 

standard deviation of 20 tests≤1.5*(0.083Mass%/2.77)=0.045Mass%). 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 May 30, 2014 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 November 30, 2014, for motor vehicle gasoline and gasoline 

fuel additives subject to the gasoline standards of this part and the volatility standards at §80.27, 

the maximum allowable standard deviation computed from the results of a minimum of 20 tests 

made over 20 days (7 or fewer tests per week and 2 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 5191-10b (Example: A gasoline having a RVP of 6.8psi: 

maximum allowable standard deviation of 20 tests≤1.5*(0.21psi/2.77)=0.11psi). 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 May 30, 2014 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 November 30, 2014, for motor vehicle gasoline 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 (7 or fewer 

tests per week and 2 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 

D86-11a for the initial boiling point, E10, E50, E90 and final boiling point. (Example: A 
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gasoline having an initial boiling point of 200C and a final boiling point of 1100C: maximum 

allowable standard deviation of 20 tests for initial boiling point≤1.5*(2.840C/2.77)=1.540C, 

maximum allowable standard deviation of 20 tests for E10≤1.5*(1.330C/2.77)=0.720C, 

maximum allowable standard deviation of 20 tests for E50≤1.5*(0.740C/2.77)=0.400C, 

maximum allowable standard deviation of 20 tests for E90t≤1.5*(1.790C/2.77)=0.970C, and 

maximum allowable standard deviation of 20 tests for final boiling 

point≤1.5*(3.330C/2.77)=1.800C ). 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 May 30, 2014 is exempt 

from the requirements of paragraph (h)(1) of this section.

(i) Precision criteria for approval of the method defined fuel parameter of benzene in 

gasoline.

(1) Precision. Beginning November 30, 2014, for motor vehicle gasoline and gasoline 

fuel additives subject to the gasoline standards of this part and the MSAT2 standards at §§80.41, 

80.101, and 80.1230, the maximum allowable standard deviation computed from the results of a 

minimum of 20 tests made over 20 days (7 or fewer tests per week and 2 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 D3606-10 (Example: A gasoline having a 

1Vol% benzene: maximum allowable standard deviation of 20 

tests≤1.5*(0.04Vol%/2.77)=0.02Vol%). 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 May 30, 2014 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 November 30, 2014, for motor vehicle diesel and diesel 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 (7 or 

fewer tests per week and 2 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 D1319-10 (Example: A diesel fuel containing 35Vol% aromatics: maximum allowable 

standard deviation of 20 tests≤1.5*(1.3Vol%/2.77)=0.70Vol%). 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
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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(j)(1) and in use prior to May 30, 2014 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.

(1) Beginning November 30, 2014, the reference installation of the method-defined fuel 

parameter for the applicable designated test method must have precision equal to 1.5 times the 

repeatability “r” of the method-defined fuel parameter’s designated test method, where “r” is the 

repeatability of the designated test method.

(i) Olefins in gasoline see paragraph (d)(1) of this section.

(ii) Aromatics in gasoline see paragraph (e)(1) of this section.

(iii) Oxygen and Oxygenate content of gasoline see paragraph (f)(1) of this section.

(iv) Reid Vapor Pressure (RVP) of gasoline see paragraph (g)(1) of this section.

(v) Gasoline Distillation see paragraph (h)(1) of this section.

(vi) Benzene in Gasoline see paragraph (i)(1) of this section.

(vii) Aromatics in Diesel see paragraph (j)(1) of this section.

(2) The reference installation of the method-defined fuel parameter for the applicable 

designated test method must be shown to be near the middle distribution of an industry monthly 

inter-laboratory crosscheck program 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 robust 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 

robust 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 robust 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 

International D6299 (incorporated by reference, see paragraph (r) of this section) for a minimum 

period of five months using good laboratory practices.
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(l) Qualification criteria for Voluntary Consensus Standard Based (VCSB) MethodDefined Parameter Test Methods.

(1) Beginning November 30, 2014, 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 International D6708 (incorporated by reference, see paragraph (r) of 

this section) 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 methoddefined 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 May 30, 2013 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 November 30, 2014, 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 method-defined 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 locally-named 

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 

International D6708 (incorporated by reference, see paragraph (r) of this section).

(4) The facility using the candidate method-defined non-VCSB test method must 

statistically establish through application of ASTM D6708 (incorporated by reference, see 

paragraph (r) of this section) 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 (incorporated by reference, see paragraph (r) of this 

section) 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 International D6708 (incorporated by reference, see paragraph 

(r) of this section) (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 International D6708 (incorporated by

reference, see paragraph (r) of this section), 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 (incorporated by reference, see paragraph (r) of 

this section) 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) EPA approval. 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.
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(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 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 to be provided by an independent third 

party must be conducted by both a professional chemist and professional statistician as specified 

in paragraph (m)(13)(i)(A) of this section. The verifying chemist and statistician must be:

(A) For a refiner, importer, oxygenate producer, and oxygenate blender, a chemist and 

statistician who has received at least a bachelor’s degree in science from an accredited college in 

the United States, with professional work experience in the petroleum or oxygenate field.

(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 third-party must provide to EPA documentation of his or her qualifications as 

part of the scientific review, including proof of appropriate college degree.
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(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 November 30, 2014, 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 on every instrument with a 

commercially available gravimetric reference material, or check standard as defined in the 

ASTM International standard practice D6299 (incorporated by reference, see paragraph (r) of 

this section) on at least a quarterly basis 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 5 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 International D6299 

(incorporated by reference, see paragraph (r) of this section) 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 5 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 follow the “Q-Procedure” 

in Annex 1.9 of ASTM International standard practice D6299 (incorporated by reference, see 

paragraph (r) of this section). 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. These records must be kept by the facility for a 

period of 5 years.

(o) Accuracy and Precision Statistical Quality Control (SQC) Requirements for the 

Voluntary Consensus Standard Based (VCSB) Method-Defined Fuel Parameters. Beginning 

November 30, 2014, 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:
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(1) Accuracy SQC. Every facility shall conduct tests of every instrument with a 

commercially available check standard as defined in the ASTM International standard practice 

D6299 (incorporated by reference, see paragraph (r) of this section) on at least a quarterly basis 

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 

International standard practice 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 5 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 International D6299 (incorporated by

reference, see paragraph (r) of this section) 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 5 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 follow the “Q-Procedure” 

in Annex 1.9 of ASTM International standard practice D6299 (incorporated by reference, see 

paragraph (r) of this section). 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. These records must be kept by the facility for a 

period of 5 years.

(p) Accuracy and Precision Statistical Quality Control (SQC) Requirements for the NonVoluntary Consensus Standard Based (Non-VCSB) Method-Defined Fuel Parameters. 

Beginning November 30, 2014, 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 commercially available 

check standard as defined in the ASTM International standard practice D6299 (incorporated by

reference, see paragraph (r) of this section) on at least a quarterly basis 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 
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respective designated test method for the fuel parameter following the guidelines of ASTM 

International standard practice 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 5 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 International standard practice D6299 (incorporated by reference, see paragraph (r) of 

this section). 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 5 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 International D6299 

(incorporated by reference, see paragraph (r) of this section) 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 5 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 follow the “Q-Procedure” 
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in Annex 1.9 of ASTM International standard practice D6299 (incorporated by reference, see 

paragraph (r) of this section) using good laboratory practices. In following the Q-Procedure if 

the plot of results from the old and new QC materials on its respective chart shows no specialcause signals, then the result of the new QC material will be considered valid. These records 

must be kept by the facility for a period of 5 years.

(q) Record retention requirements for the test methods approved under this subpart.

(1) 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.

(2) [Reserved]

(r) Materials incorporated by reference. The Director of the Federal Register approved 

the incorporation by reference of the documents listed in this section as prescribed in 5 U.S.C. 

552(a) and 1 CFR 51. Anyone may inspect copies at the U.S. EPA, Air and Radiation Docket 

and Information Center, 1301 Constitution Ave., N.W., Room B102, EPA West Building, 

Washington, DC, 20460, under EPA docket ID Number EPA–HQ–OAR–2011–0135, or at the 

National Archives and Records Administration (NARA). The telephone number for the Air 

Docket Public Reading Room is (202) 566-1742. 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. For 

further information on these test methods, please contact the Environmental Protection Agency

at 734-214-4582.

(1) ASTM International material. Anyone may purchase copies of these materials from 

the ASTM International (ASTM), 100 Barr Harbor Dr., West Conshohocken, PA 19428-2959, or 

by contacting ASTM International customer service at 10-832-9585, or by contacting the email 

address of service@astm.org from the ASTM International Web site of http://www.astm.org.

(i) ASTM International standard practice D6708-08 (“ASTM International D6708”), 

“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 

December 15, 2008.

(ii) ASTM International standard practice D6299-10ε1 (“ASTM International D6708”), 

“Standard Practice for Applying Statistical Quality Assurance and Control Charting Techniques 

to Evaluate Analytical Measurement System Performance”, approved March 1, 2010.

(2) [Reserved]

7. Section 80.65 is amended by:

a. Revising paragraph (d)(1).

b. Removing and reserving paragraph (d)(2)(iv).

c. Removing and reserving paragraph (d)(2)(v)(E).
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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).

§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) * * *

(E) [Reserved]

* * * * *

(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, 4321–543321–95–000002, 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:
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(i) Be based on a representative sample of the reformulated gasoline or RBOB that is 

analyzed using the methodologies specified in §80.46 through November 29, 2014, or, beginning 

November 30, 2014, in §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. 

(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 of 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 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.
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(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 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 

November 29, 2014, and the methodologies specified in §80.47 beginning November 30, 2014.

* * * * *

(3) * * *

(iii) * * *

(A) A report for the period January through March shall be submitted by June 1; a report 

for the period April through June shall be submitted bySeptember 1; a report for the period July

through September shall be submitted byDecember 1; and a report for the period October 

through December shall be submitted byMarch 31. Beginning, January 1, 2014, 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 be used 

only when the designated independent laboratory per paragraph (f)(2) of this section is 

unavailable and cannot perform testing required for compliance.
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(i) The alternate independent laboratory must meet all provisions of this section for 

designated independent laboratories.

(ii) An alternate independent laboratory may not be used to select a preferred test result. 

The alternate laboratory may only be used on those occasions where operational necessity causes 

a need for it (e.g., the primary designated laboratory is closed, the apparatus for certain test 

methods are down, or independent laboratory personnel are not available).

* * * * *

(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

* * * * *

(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.

* * * * *
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Subpart D--[Amended] 

8. Section 80.75 is amended by:

a. Revising paragraphs (a)(1)(i) through (iv).

b. By revising paragraph (a)(2)(v)(B).

c. Revising paragraph (a)(2)(viii)(D).

d. Revising paragraph (a)(2)(ix)(F).

e. Removing and reserving paragraph (b).

f. Revising paragraph (c)(1).

g. Revising paragraph (d) introductory text.

h. Revising paragraph (d)(1).

i. Revising paragraph (d)(2)(iii).

j. Revising paragraph (e) introductory text.

k. Revising paragraph (e)(1).

l. Revising paragraph (g) introductory text.

m. Revising paragraph (h) introductory text.

n. Revising paragraph (i).

o. Removing and reserving paragraph (k).

p. Revising paragraph (l).

q. Revising paragraph (o) introductory text.

§ 80.75 Reporting Requirements

* * * * *

(a) * * *

(1) * * *

(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; and

(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.
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(2) * * *

(v) * * *

(B) The properties, along with identification of the test method used to measure those 

properties, pursuant to §§80.65 and 80.66;

* * * * *

(viii) * * * 

(D) The volume, properties (along with identification of the test method used to measure 

those properties), and designation of the batch.

(ix) * * *

(F) The properties of the butane batch, along with the identification of the test method 

used to measure those properties, specified by the butane supplier, or the properties specified in 

§80.82(c) or (d), as appropriate;

* * * * *

(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 annual report. 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 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 
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during the previous toxics averaging period. Beginning January 1, 2014, the information 

required by this paragraph (d) shall be submitted with the annual report.

(2) * * *

(iii) The actual total content of benzene, along with identification of the test methods 

used to measure the content of benzene;

* * * * *

(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. Beginning January 1, 2014, the 

information required by this paragraph (e) shall be submitted with the annual report.

* * * * *

(g) NO X 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, 2012.

* * * * *

(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 information 

specified in paragraphs (h)(1) through (3) of this section for any benzene credits that are 

transferred from or to another refinery or importer. Beginning January 1, 2014, the information 

required by this paragraph (h) shall be submitted with the annual report.

* * * * *

(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 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. Beginning January 1, 2014, the information 

required by this paragraph (i) shall be submitted with the annual report. 
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* * * * *

(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 pergallon basis, the refiner or importer shall submit to the Administrator, by March 1 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.

* * * * *

(o) Additional reporting requirements for refiners that blend butane with reformulated 

gasoline or RBOB. For refiners that blend any butane with reformulated gasoline or RBOB 

under §80.82, the refiner shall submit to the Administrator, by March 1 of each year, a report for 

the refinery which includes the following information for the previous calendar year:

* * * * *

9. Section 80.82 is amended by:

a. Revising the introductory text.

b. Revising paragraphs (a) through (d).

c. Revising paragraph (e)(1).

d. Adding paragraphs (i) and (j).

§80.82 Butane blending. 

A refiner for any refinery that produces gasoline by blending butane with previously 

certified gasoline 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
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(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 that any applicable equivalent emissions 

performance standards 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 per-gallon standards in §80.41, 

as determined using the test methods in §80.46.

(c) Commercial grade butane is defined as butane for which test results demonstrate that 

the butane is 95% pure and has all of 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.

(d) Non-commercial grade butane is defined as butane for which test results demonstrate 

the butane has all of 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 §80.47, that each batch of conventional gasoline 

blended with butane meets the volatility standards specified in §80.27.
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* * * * *

(i) A refiner who only blends commercial grade or non-commercial grade butane into 

PCG may meet the sampling and testing requirements of subpart O of this part by meeting the 

requirements of paragraphs (a) through (f) and (h)(3) of this section and all of the following 

additional requirements:

(1) The per-gallon sulfur content of every batch of butane must not exceed 10 ppm.

(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 §80.47.

(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 10 

ppm 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 noncommercial grade.

(5) The quality assurance testing requirement of paragraph (b)(1) of this section applies 

regardless of whether the butane is commercial grade or noncommercial 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.

10. 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).
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§80.101 Standards applicable to refiners and importers.

* * * * *

(i) * * *

(1) * * *

(i)(A) Through November 29, 2014, 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 November 30, 2014, 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 either of the following:

(1) The test methods specified under §80.46, through November 29, 2014.

(2) The test methods specified under §80.47, beginning November 30, 2014.

* * * * *

(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 November 29, 2014, or under §80.47 

beginning November 30, 2014.

* * * * *

Subpart E--[Amended] 

11. Section 80.105 is amended by:

a. Revising paragraph (a)(5)(v).

b. Revising paragraph (a)(5)(vi)(D).

c. Revising paragraphs (a)(5)(vii)(F) and (a)(5)(vii)(G).

d. Revising paragraph (a)(7)(iii).
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e. Revising paragraph (d)(2).

§ 80.105 Reporting Requirements.

(a) * * *

(5) * * * 

(v) The properties, along with identification of the test method used to measure those 

properties, pursuant to §80.101(i);

(vi) * * *

(D) The volume, properties, along with identification of the test method used to measure 

those properties, and designation of the batch;

(vii) * * *

(F) The properties of the butane batch specified by the butane supplier, along with 

identification of the test method used to measure those properties of the butane, 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 using the appropriate test method at §80.46 through November 

29,2014, and at §80.47 beginning November 30, 2014; and

* * * * *

(7) * * *

(iii) A statement that the gasoline produced using butane meets all applicable downstream 

standards that apply to conventional gasoline under Subpart E of this part, along with the test 

methods used to determine compliance with the downstream standards that apply to conventional 

gasoline under Subpart E of this part; and

* * * * * 

(d) * * *

(2) Submitted to EPA by March 31 each year for the prior calendar year averaging 

period; and

* * * * * 

12. Section 80.161 is amended by:
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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 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. 

* * * * *
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(v) In the case of a national or PADD certification (pursuant to §80.163(a)(1), (a)(1)(i), 

(a)(1)(ii), 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.

* * * * *

13. Section 80.163 is amended by adding a new paragraph (a)(1)(iii) to read as follows:

§ 80.163 Detergent certification options.

* * * * *

(a) * * *

(1) * * *

(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.

* * * * *

14. Section 80.164 is amended by revising paragraph (a) to read as follows:
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§ 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), (a)(1)(i), (a)(1)(ii), and 

(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.

* * * * *

15. 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.

(a) Fuel injector deposit control testing.

(1) The required test fuel must produce no more than 5% flow restriction in any one 

injector when tested in accordance with ASTM D 5598–94, “Standard Test Method for 

Evaluating Unleaded Automotive Spark-Ignition Engine Fuel for Electronic Port Fuel Injector 

Fouling,” 1994, which is incorporated by reference pursuant to §80.178. At the option of the 

certifier, fuel injector flow may be measured at intervals during the 10,000 mile test cycle 

described in ASTM D 5598–94, 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 D 5500–94, “Standard Test Method for Vehicle Evaluation of Unleaded Automotive 

Spark-Ignition Engine Fuel for Intake Valve Deposit Formation,” 1994, which is incorporated by 

reference pursuant to §80.178. 
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(c) If conducted using test fuels meeting all relevant requirements of §80.164, and 

completed prior to September 3, 1996, then the PFID and IVD control test procedures required 

for detergent certification in California (specified in section 2257 of Title 13, California Code of 

Regulations) will also be considered acceptable. California Air Resources Board, “Test Method 

for Evaluating Port Fuel Injector (PFI) Deposits in Vehicle Engines”, March 1, 1991, and 

California Air Resources Board, “BMW—10,000 Miles Intake Valve Test Procedure”, March 1, 

1991, are incorporated by reference pursuant to §80.178. 

16. Section 80.167 is amended by revising paragraph (a) to read as follows:

§ 80.167 Confirmatory testing.

* * * * *

(a) Confirmatory testing conducted to evaluate the validity of detergent certifications 

under the national, PADD, or fuel-specific options under §80.163(a)(1), (a)(1)(i), (a)(1)(ii), and 

(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.

* * * * *

17. A new section 80.175 is added to subpart G and reserved as follows:

§ 80.175 [Reserved]

18. A new section 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.
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(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 - 04(2009), “Standard Test Method for Dynamometer Evaluation of 

Unleaded Spark-Ignition Engine Fuel for Intake Valve Deposit Formation”, which is 

incorporated by reference pursuant to §80.178.

(1) Tests conducted for the intake valve deposit demonstration test pursuant to 

§80.177(b)(1)(iv) 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 D 6201 - 04(2009).

(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.
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(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 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 
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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 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.
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(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.

(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.

(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.
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(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.

19. A new section 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.

(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 D 4814–11, “Standard Specification 

for Automotive Spark-Ignition Engine Fuel”, which is incorporated by reference pursuant to 

§80.178.

(b) Test fuel for intake valve deposit testing: This paragraph provides specifications for 

the test fuels required for use in the test procedure specified in §80.176(b).
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(1) The test fuel must contain levels of the specified parameters consistent with the 

requirements of this section. 

(i) 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 - 11a “Standard Specification for 

Denatured Fuel Ethanol for Blending with Gasolines for Use as Automotive Spark-Ignition 

Engine Fuel”, which is incorporated by reference pursuant to §80.178.

(ii) 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:

(A) 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.

(B) 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 the 

following criteria:

(1) The heavy FCC gasoline must be designated by the commercial refiner as heavy FCC 

gasoline.

(2) The heavy FCC gasoline must have an API gravity less than 45 and a T90 distillation 

temperature greater than 325°F.

(iii) The test fuel must contain no less than 28 volume percent aromatics.

(iv) The test fuel must contain no less than 240 ppm sulfur. At least 60 percent of the 

sulfur must be derived from FCC gasoline that meets the specifications in paragraph (b)(1)(ii) of 

this section.

(v) The test fuel must have a T90 distillation temperature of no less than 290°F.

(vi) 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).

(vii) 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 distillation. 

Butanes and pentanes may be used for vapor pressure adjustment. The use of chemical grade 

streams is prohibited.
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(2) [Reserved]

(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 regarding the specifications for the test fuel used for fuel injector deposit 

testing.

(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 regarding the specifications for the formulation of the test fuel used for fuel 

injector deposit testing.

(i) The test fuel must meet the requirements for federal emissions test gasoline specified 

in §§80.113 and 80.112 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).

20. A new section 80.178 is added to subpart G to read as follows:

§ 80.178 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, the Environmental Protection Agency (EPA) 

must publish notice of change in the Federal Register and the material must be available to the 

public. All approved material is 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. This 

material is also available for inspection at the EPA Docket Center, Docket No. EPA–HQ–OAR–

2005–0161, EPA/DC, EPA West, Room 3334, 1301 Constitution Ave., NW, Washington DC. 

The telephone number for the Air Docket is (202) 566–1742. Also, this material is available 

from the source listed in paragraphs (b) and (c) of this section.
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(b) ASTM International, 100 Barr Harbor Drive, P.O. Box C–700, West Conshohocken, 

Pennsylvania 19428 (1–800–262–1373, www.astm.org ).

(1) ASTM D 5598–94, “Standard Test Method for Evaluating Unleaded Automotive 

Spark-Ignition Engine Fuel for Electronic Port Fuel Injector Fouling,” 1994; IBR approved for 

§80.165.

(2) ASTM D 5500–94, “Standard Test Method for Vehicle Evaluation of Unleaded 

Automotive Spark-Ignition Engine Fuel for Intake Valve Deposit Formation,” 1994; IBR 

approved for §80.165.

(3) ASTM D6201 - 04(2009) (“ASTM D 6201”), Standard Test Method for 

Dynamometer Evaluation of Unleaded Spark-Ignition Engine Fuel for Intake Valve Deposit 

Formation; IBR approved for §80.176. 

(4) ASTM D 4814–11, “Standard Specification for Automotive Spark-Ignition Engine 

Fuel”, IBR approved for §80.177.

(5) ASTM D4806 - 11a “Standard Specification for Denatured Fuel Ethanol for Blending 

with Gasolines for Use as Automotive Spark-Ignition Engine Fuel”, IBR approved for §80.177.

(c) California Air Resources Board, 1001 "I" Street, P.O. Box 2815, Sacramento, CA 

95812 (800) 242-4450, http://www.arb.ca.gov).

(1) California Air Resources Board, “Test Method for Evaluating Port Fuel Injector (PFI) 

Deposits in Vehicle Engines”, March 1, 1991; IBR approved for §80.165.

(2) California Air Resources Board, “BMW—10,000 Miles Intake Valve Test 

Procedure”, March 1, 1991; IBR approved for §80.165.

Subpart H—[Amended] 

21. Section 80.330 is amended by revising paragraphs (c)(1), (d)(1), and (d)(2) 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 November 29, 2014. 
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Beginning November 30, 2014, for purposes of paragraph (a) of this section, refiners and 

importers shall use a method approved in §80.47.

* * * * *

(d) * * *

(1) Refiners and importers shall use the method provided in §80.46(a)(2) to measure the 

sulfur content of butane when the butane constitutes a batch of gasoline through November 29, 

2014. Beginning November 30, 2014, refiners and importers shall use a method approved 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 November 29, 2014. Beginning November 30, 

2014, except as provided in paragraph (d)(1) of this section, refiners and importers shall use a 

method approved in §80.47 to measure the sulfur content of butane.

* * * * * 

22. Section 80.370 is amended by:

a. Revising paragraph (a)(7)(iv).

b. Revising paragraph (d)(2).

§ 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.

* * * * *
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Subpart I—[Amended]

23. 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 purchaser-consumer 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.

24. 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?

* * * * *

(a) From June 1, 2010 through November 30, 2014, any retailer or wholesale purchaserconsumer 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.

* * * * *

25. Section 80.573 is amended by revising paragraph (a) to read as follows:
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§ 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.

* * * * *

26. 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

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.

(1) For US Mail: U.S. EPA, Attn: Diesel Sulfur Alternative Label Request, 6406J, 1200 

Pennsylvania Avenue, NW, Washington, DC 20460.
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(2) For overnight or courier services: U.S. EPA, Attn: Diesel Sulfur Alternative Label 

Request, 6406J, 1310 L Street, NW, 6th floor, Washington, DC 20005. (202) 343-9038.

27. Section 80.580 is amended by:

a. Revising paragraph (e) introductory text.

b. Revising paragraph (e)(1) introductory text.

c. Revising paragraphs (e)(1)(i) through (e)(1)(iv).

§ 80.580 What are the sampling and testing methods for sulfur?

* * * * *

(e) Materials incorporated by reference. The Director of the Federal Register approved 

the incorporation by reference of the documents listed in this section as prescribed in 5 U.S.C. 

552(a) and 1 CFR 51. Anyone may inspect copies at the U.S. EPA, Air and Radiation Docket 

and Information Center, 1301 Constitution Ave., N.W., Room B102, EPA West Building, 

Washington, DC, 20460, under EPA docket ID Number EPA–HQ–OAR–2011–0135, or at the 

National Archives and Records Administration (NARA). The telephone number for the Air 

Docket Public Reading Room is (202) 566-1742. 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. For 

further information on these test methods, please contact the Environmental Protection Agency

at 734-214-4582.

(1) ASTM International material. Anyone may purchase copies of these materials from 

ASTM International, 100 Barr Harbor Dr., West Conshohocken, PA 19428-2959, or by

contacting ASTM International customer service at 610-832-9585, or by contacting the email 

address of service@astm.org from the ASTM International Web site of http://www.astm.org.

(i) ASTM International standard method D2622-10 (“ASTM International D2622”), 

“Standard Test Method for Sulfur in Petroleum Products by Wavelength Dispersive X-Ray

Fluorescence Spectrometry”, approved February 15, 2010.

(ii) [Reserved]

(iii) ASTM International standard method D4294-10 (“ASTM International D4294”), 

“Standard Test Method for Sulfur in Petroleum Products by Energy Dispersive X-Ray

Fluorescence Spectrometry”, approved February 15, 2010.

(iv) ASTM International standard method D5453-09 (“ASTM International D5453”), 

“Standard Test Method for Sulfur in Petroleum Products by Energy Dispersive X-Ray

Fluorescence Spectrometry”, approved June 15, 2009.

* * * * *
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28. 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.

* * * * *

29. Section 80.604 is amended by revising paragraphs (f)(3) and (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.

Subpart L--[Amended]

30. 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).
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(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.

* * * * *

31. 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) and the benzene content must be measured by

sampling the ethanol actually added to the conventional gasoline or CBOB and testing it for 

benzene content. 

* * * * *

32. Section 80.1347 is amended to read as follows: 

1. By revising paragraphs (a)(3)(i) and (a)(5).

2. By adding a new paragraph (a)(6).

§ 80.1347 What are the sampling and testing requirements for refiners and importers?

(a) * * *

(3)(i) Each sample shall be tested in accordance with the methodology specified at 

§80.46(e) through November 29, 2014, to determine its benzene concentration for compliance 

with the requirements of this subpart. Beginning November 30, 2014, each sample shall be 

tested in accordance with the methodology specified at §80.46(e) or §80.47 to determine its 

benzene concentration for compliance with the requirements of this subpart. Any negative test 

result must be reported as zero.

* * * * *
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(5) Exclusion of previously certified gasoline (PCG).

(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 blendstock 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.

* * * * *

33. Section 80.1348 is revised to read as follows: 

§80.1348 What gasoline sample retention requirements apply to refiners and importers?

(a) Through November 29, 2014, the gasoline sample retention requirements specified in 

subpart H 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).
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(b) Beginning November 30, 2014, 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 §80.46(e).

34. 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. 

35. Section 80.1354 is amended by:

a. Revising paragraph (b)(2).

b. Revising paragraph (d)(2).

§80.1354 What are the reporting requirements for the gasoline benzene program?

* * * * *

(b) * * *

(2)(i) The annual average benzene concentration, along with identification of the test 

method(s) used to measure the annual average benzene concentration, per §80.1238.

(ii) The maximum average benzene concentration, along with identification of the test 

method(s) used to measure the maximum average benzene concentration, per §80.1240(b).

* * * * *

(d) * * *

(2) Submitted to EPA by March 31 each year for the prior calendar year averaging 

period.

* * * * *

36. Section 80.1451 is amended by:

a. Revising paragraph (a)(1) introductory text.
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b. Revising paragraph (f)(2).

§ 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 and shall include all of the following information:

* * * * * 

(f) * * *

(2) Quarterly reports shall be submitted by the required deadline as shown in Table 1. 

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 to §80.1451: Quarterly Reporting Deadlines

Calendar Quarter Time Period Covered Quarterly Report Deadline

Quarter One January 1 - March31 June 1

Quarter Two April 1 – June 30 September 1

Quarter Three July 1 – September 30 December 1

Quarter Four October 1 – December 31 March 31

* * * * * 

37. A new subpart O is added to part 80 to read as follows:

Subpart O—Gasoline Sulfur

§80.1600 Definitions for subpart O.

§80.1601 Fuels subject to the provisions of this subpart.

§80.1602 Implementation dates for refiners and importers.

§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 carry-forward 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 Blender requirements.

§80.1610 Standards and requirements for producers of denatured fuel ethanol and other 

oxygenates for use by gasoline oxygenate blenders.

§80.1611—80.1612 [Reserved]
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§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]

§80.1625 Hardship provisions.

§80.1626—80.1629 [Reserved]

§80.1630 Sampling and testing requirements for refiners and importers.

§80.1631 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—80.1649 [Reserved]

§80.1650 Registration.

§80.1651 Product transfer document requirements.

§80.1652 Reporting requirements.

§80.1653 Recordkeeping.

§80.1654 California gasoline requirements.

§80.1655 National security exemptions.

§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 under subpart O.

§80.1663 Defenses for a violation of a prohibited act under subpart O.

§80.1664 [Reserved]

§80.1665 Penalties.

§80.1666 Additional requirements for foreign small refiners and foreign small volume 

refineries.

§80.1667 Attest engagement requirements.

§80.1668—80.1674 [Reserved]

§80.1675 Incorporation by reference.

§80.1600 Additional definitions for subpart O.
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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 Sulfur-FRGAS has the meaning given in §80.1666(a)(5).

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, the 

Commonwealth of Puerto Rico, the Virgin Islands, Guam, American Samoa, and the 

Commonwealth of the Northern Mariana Islands (collectively referred to in this subpart as “the 

United States”).

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 gasoline product (TGP) has the meaning given at §80.84(a)(3).

Transmix processing facility has the meaning given at §80.84(a)(4).

Transmix processor has the meaning given at §80.84(a)(5).

Transmix blender has the meaning given at §80.84(a)(7).

§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 (not including oxygenates) blended with PCG, as defined in §80.2(d), 

subject to the provisions of §80.1640.

(3) Oxygenates blended with gasoline, RBOB, or CBOB. 
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(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 U.S.

(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 Implementation dates for refiners and importers.

(a) The standards and requirements for gasoline sulfur under this subpart O (at §80.1603) 

shall apply to gasoline produced or imported by any refiner or importer beginning January 1, 

2017, except as provided by the credit provisions of §§80.1615 and 80.1616, and the provisions 

applicable to small refiners and small volume refineries.

(b) The standards and requirements for gasoline sulfur under subpart H of this part 80 

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.

(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.
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(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 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) 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.
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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.

(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) A refiner or importer may include oxygenate added downstream from the refinery or 

import facility when calculating the sulfur content, provided the following requirements are met:

(1) For oxygenate added to conventional gasoline or CBOB, the refiner or importer must 

comply with the requirements of §80.101(d)(4)(ii), except that the sulfur content and volume of 

the oxygenate shall be determined in accordance with paragraph (d)(3) of this section.

(2) For oxygenate added to RBOB, the refiner or importer must comply with the 

requirements of §80.69(a), except that the sulfur content and volume of the oxygenate shall be 

determined in accordance with paragraph (d)(3) of this section.

(3) Where oxygenate added downstream from the refinery or import facility is included 

in calculating the sulfur content under this paragraph (d):

(i) The refiner or importer must separately test any RBOB or CBOB for sulfur content 

and use that test result in calculating the sulfur content of the RFG or conventional gasoline and 

calculate the effect of downstream added ethanol by using the assumptions in paragraphs 

(d)(3)(ii) and (iii) of this section. The reported volume of the batch is the combined volume of 

the RBOB or CBOB and the downstream added oxygenate.

(ii) For RBOB, the sulfur test result obtained from testing a hand blend under the terms of 

§80.69(a) shall not be used for sulfur reporting purposes.

(iii) The refiner or importer must use an assumed sulfur content of 10.00 ppm for the 

oxygenate added downstream.

(iv) For ethanol added downstream, the refiner or importer calculations shall assume that 

10.00 volume percent ethanol is added to the RBOB unless some lesser amount of ethanol is 

actually blended.

(v) RBOB, CBOB, and conventional gasoline must meet the per-gallon sulfur standard of 

§80.1603(a)(2) prior to calculating any dilution from the oxygenate added downstream.

(4) 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) Refiners and importers must exclude from compliance calculations all of 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) 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, CSVy≤ (Vy× 10), 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 ppm-gallons.

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, CSVy> 

(Vy× 10). 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 carry-forward for refiners and importers.

(a) Deficit carry-forward.

(1) A refiner or importer may exceed the annual average sulfur standard for a given 

calendar year, creating a compliance deficit, provided that the requirements of paragraph (a)(2) 

of this section are met.

(2) When a compliance deficit is created per paragraph (a)(1) of this section, in the 

calendar year following the year the standard is not met, the refinery or importer must:

(i) Achieve compliance with the annual average sulfur standard in §80.1603(a)(1); and

(ii) Use 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 requirements instead 

of the 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 
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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.

(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 applicable 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 through either of the methods 

provided in paragraph (d)(1) of this section or through the alternative method provided in 

paragraph (d)(2) of this section.

(1)(i) Sample and test the blendstock 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, that blendstock is deemed in violation of the 

gasoline sulfur standards of this subpart O.
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(2) As an alternative to the sampling and testing procedures described in paragraph (d)(1) 

of this section, the following procedures may be used: 

(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 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. 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).
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(b) Beginning March 1, 2017, the DFE or other oxygenate used must comply with the 

requirements of §80.1610. Prior to March 1, 2017, DFE is subject to the sulfur requirements of 

§80.385(e). 

§80.1610 Standards and requirements for producers of denatured fuel ethanol and other 

oxygenates for use by gasoline oxygenate blenders.

Beginning January 1, 2017, producers of denatured fuel ethanol (DFE) or other oxygenates for 

use by oxygenate blenders under §80.1609 must comply with the following requirements:

(a) Standards.

(1) The sulfur content must not be greater than 10 ppm as determined in accordance with 

the test requirements of §80.1630.

(2) The DFE or other oxygenate must be composed solely of carbon, hydrogen, nitrogen, 

oxygen and sulfur.

(3) In the case of DFE, only gasoline, RBOB, CBOB, or natural gas liquids may be used 

as denaturants. 

(4) The concentration of all denaturants used in DFE is limited to a maximum of 2.

volume percent.

(b) Registration. Unless registered under §80.1450, the producer of DFE or other 

oxygenate must register with EPA pursuant to the requirements of §80.1650. 

(c) PTDs. The producer of DFE or other oxygenate must initiate a PTD for each batch of 

DFE or other oxygenate that it ships from its facility which contains the statement in either 

paragraph (c)(1) or (c)(2) of this section, as applicable. 

(1) For DFE, “Meets EPA standards for denatured fuel ethanol for use in gasoline”; or

(2) For oxygenates other than DFE, “Meets EPA standards for motor fuel oxygenates for 

use in gasoline” 

(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. 

(d) 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 
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each subsequent batch during the calendar year being assigned the next sequential number ( e.g. , 

4321–54321–95–000001, 4321–543321–95–000002, etc.)

§§80.1611—80.1612 [Reserved]

§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 §79.2(f), must meet the following 

requirements: 

(1)(i) Except as otherwise provided, this section applies to any additive, as defined in 

§79.2(e), manufactured for use in gasoline that is not an oxygenate compound, and that is sold 

for use at a concentration of less than 1.0% by volume. 

(ii) Oxygenate compound additives subject to the 10 ppm per-gallon sulfur standard and 

the requirements of §80.1610 are not subject to the provisions of this section except for the 

provisions of paragraph (b)(1) of this section.

(2) 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.

(3) 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 upon request.

(4) 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 comply with the requirements in 

paragraph (a)(2) of this section.

(b) The following provisions apply to parties who are downstream of the gasoline refiner 

or importer and who blend additives to gasoline, RBOB or CBOB and who are not refiners.

(1) 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 prohibition in §80.1660(e) and the downstream 

gasoline sulfur standard of §80.1604(b).
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(2) On any occasion where an additive blender blends an additive (subject to the 

requirements of §80.1613(a)) at a concentration of less than 1.0% by volume, it is subject to the 

prohibition in §80.1660(f) and the downstream gasoline sulfur standard of §80.1604(b).

(3) On any occasion where an additive blender blends an additive at a concentration of 

1.0% by volume or greater, it is a fuel manufacturer as defined in §79.2(d), and is subject to all 

the provisions that apply to refiners under this subpart O.

§80.1614 [Reserved]

§80.1615 Credit generation.

(a) Who may generate credits? Credits may be generated under this subpart O, as 

provided in paragraphs (b), (c), and (d) of this section, by the following entities:

(1) U.S. refiners, including small refiners under §80.1620, and refiners owning small 

volume refineries under §80.1621. Foreign refiners may not generate credits. 

(2) Importers.

(b) Early credit generation—January 1, 2014 through December 31, 2016.

(1) Early credits may be generated for gasoline produced or imported from January 1, 

2014 through December 31, 2016, by a refiner, including small refiners and owners of small 

volume refineries approved pursuant to §80.1622, and importers.

(2) A refiner or importer may generate early credits for gasoline it produces at a refinery 

or imports during an annual averaging period when its annual average sulfur level, calculated in 

accordance with the provisions of 80.1603(c), is less than 30 ppm.

(3)(i) The number of early credits generated shall be calculated annually for each 

applicable averaging period according to the following equation:

ECa = [Va x (30-Sa)] - CRa

Where:

ECa = Early credits generated during the annual averaging period, in ppm-gallons, for use 

pursuant to §80.1616.

Sa = Annual average sulfur level, calculated in accordance with the provisions of 

80.1603(c), in ppm.

Va = Total volume of gasoline produced or imported during the averaging period, in 

gallons.

CRa = Credits generated during the annual averaging period per §80.310, in ppm-gallons, 

for use pursuant to subpart H.

(ii) No credits shall be generated unless the value of ECa is positive.
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(iii) The value of ECa shall be rounded to the nearest ppm-gallon in accordance with the 

rounding procedure specified in §80.9.

(4) A refiner or importer may include any downstream added oxygenates included in its 

RFG or conventional gasoline volume under the provisions of §§80.69 and 80.101(d)(4), 

respectively, for the purpose of generating credits.

(5) All, some, or no credits generated during the time period specified in paragraph (b)(1) 

of this section must be designated as subject to the requirements of subpart H. Any remaining 

credits must be designated as subject to the requirements of this subpart O.

(c) Standard credit generation—beginning January 1, 2017.

(1) Refiners, including small refiners and owners of small volume refineries approved 

pursuant to §80.1622, and importers may generate standard credits for the gasoline produced at a 

refinery or imported during an annual averaging period when the annual average sulfur level of 

the refiner, refinery or importer, as applicable, and as calculated in accordance with the 

provisions of §80.1603(c), is less than 10 ppm.

(2)i) The number of standard credits generated shall be calculated annually for each 

applicable averaging period according to the following equation:

SCa = [Va x (10-Sa)] - CRa

Where:

SCa = Standard credits generated during the annual averaging period, in ppm-gallons, for 

use pursuant to §80.1616.

Sa = Annual average sulfur level, calculated in accordance with the provisions of 

§80.1603(c), in ppm.

Va = Total volume of gasoline produced or imported during the averaging period, in 

gallons.

CRa = Credits generated during the annual averaging period per §80.310, in ppm-gallons, 

for use pursuant to subpart H. This term is applicable only to small refiners and small volume 

refineries per paragraph (c)(1) of this section, and only prior to January 1, 2020. Beginning 

January 1, 2020, the value of this term is zero.

(ii) No credits shall be generated unless the value of SCa is positive.

(iii) The value of SCa shall be rounded to the nearest ppm-gallon in accordance with the 

rounding procedure specified in §80.9.

(3) A refiner or importer may include any downstream added oxygenates included in its 

RFG or conventional gasoline volume under the provisions of §§80.69 and 80.101(d)(4), 

respectively, for the purpose of generating credits.
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(4) Prior to January 1, 2020, credits generated under this paragraph (c) by small refiners 

and owners of small volume refineries per paragraph (c)(1) of this section must be designated as 

subject to the requirements of subpart H. Any remaining credits must be designated as subject to 

the requirements of this subpart O.
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§80.1616 Credit use and transfer.

(a) Credit use.

(1) Credits may be used to meet the applicable annual average sulfur standards of 

§80.1603(a)(1).

(2) Credits must have been generated pursuant to the requirements of §80.1615.

(3) Only obligated parties under this subpart O may generate, use, transfer or own credits 

generated under this subpart O. 

(4) Credit life - Early Credits.

(i) Early credits generated under §80.1615(b) are valid for use for the 2017 through 2019 

compliance years. All early credits will expire and become invalid after February 29, 2020, 

when the 2019 annual compliance report is due.

(ii) Early credits may be used for compliance with the annual average sulfur standard of 

§80.1603(a)(1) by refiners and importers.

(5) Credit life – Standard Credits.

(i) Standard credits generated under §80.1615(c) are valid for use for five (5) years from 

the year in which they are generated. For example, standard credits generated in 2017 may be 

used for compliance through the 2022 compliance period (they would expire and become invalid 

after February 28, 2023, the 2022 annual compliance report due date).

(ii) Standard credits may be used for compliance with the annual average sulfur standard 

of §80.1603(a)(1) by refiners and importers.

(6) A refiner or importer possessing credits must use all credits prior to falling into a 

compliance deficit.

(7) In no case may a credit be transferred more than twice before being used or 

terminated.

(b) Credit transfers.

(1) Credits obtained from other obligated parties may be used to meet the annual average 

standards of this subpart O, if all of 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.
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(iii) Any credit transfer takes place no later than February 28 following the calendar year 

averaging period when the credits are used.

(iv) The credit has not been transferred more than twice. The first transfer by the refiner 

or importer who generated the credit may only be made to a refiner or importer who intends to 

use the credit; 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.

(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 of the following: 

(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 of 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.

§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 of the following criteria and has been approved by EPA as a small refiner per 

§80.1622:
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(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 2011 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 2011.

(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 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:

(1) Refiners with refineries built or started up on or after January 1, 2011.

(2) Persons who exceed the employee or crude oil capacity criteria under this section on 

January 1, 2011, 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, 

2011 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 
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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 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 addresses listed in 

§80.1622.

§80.1621 Small volume refinery definition.

(a) For the purposes of this subpart O, a gasoline small volume refinery is defined as any

refinery that meets all of 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 2011 (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:

(1) Refineries built or started up on or after January 1, 2012.
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(2) Persons who exceed the crude oil throughput under this section for calendar year 2011 

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 must 

be submitted to EPA by March 31, 2014.

(b) To qualify for small refiner status under this subpart a refiner must submit an 

application to EPA containing all of 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, 

2011 through December 31, 2011.

(ii) The average number of employees at each location, based on the number of 

employees for each pay period for the period January 1, 2011 through December 31, 2011.

(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 period 

January 1, 2011 through December 31, 2011. 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, 2011 through December 

31, 2011, to one of the addresses 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, 2011.
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(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 of 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 the Energy Information Administration (EIA) of the U.S. 

Department of Energy (DOE), for the period January 1, 2011 through December 31, 2011. 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, 2011 through December 31, 2011, to one of 

the addresses 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, 2011.

(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), as applicable, of this section, must 

demonstrate compliance with §80.1620, and must be submitted by March 31, 2014 to one of the 

addresses listed in paragraph (g) of this section.

(e) A refiner who qualifies as a small refiner or small volume refinery under this subpart 

and subsequently fails to meet all of 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.
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(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, and/or §80.1621 shall be sent to one of the 

following addresses:

(1) For U.S. Mail: U.S. EPA—Attn: Tier 3 Program (Small Refiner/Small Volume 

Refinery), 6406J, 1200 Pennsylvania Avenue, NW., Washington, DC 20460.

(2) For overnight or courier services: U.S. EPA, Attn: Tier 3 Program (Small 

Refiner/Small Volume Refinery), 6406J, 1310 L Street, NW, 6th floor, Washington, DC 20005.

§§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 of 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 of 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 March 

31, 2014 to one of the addresses listed in paragraph (d) of this section.

(b) Extreme unforeseen circumstances hardship.
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(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 of the following reasons:

(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) The hardship extension application must contain a letter signed by the president or the 

chief operating 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.

(d) Hardship applications under this section must be submitted in writing to one of the 

following addresses:

(1) For U.S. Mail: U.S. EPA—Attn: Tier 3 Program (Hardship Application), 6406J, 1200 

Pennsylvania Avenue, NW., Washington, DC 20460.

(2) For overnight or courier services: U.S. EPA, Attn: Tier 3 Program (Hardship 

Application), 6406J, 1310 L Street, NW, 6th floor, Washington, DC 20005.

§80.1630 Sampling and testing requirements for refiners and importers.

(a) Sample and test each batch of gasoline.

(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 
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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) Except as provided in paragraph (a)(3) of this section, the requirements of this section 

apply beginning January 1, 2017.

(3)(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 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)(3)(i)(B).

(ii) Refiners who seek an exemption under paragraph (a)(3)(i) of this section must 

comply with any request by EPA 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)(3)(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)(3)(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 and 

importers shall sample each batch of gasoline by using one of the methods specified in 40 CFR 

80.8.
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(c) Test method for measuring sulfur content of gasoline.

(1) For purposes of paragraph (a) of this section, refiners and importers shall use the 

method provided in §80.47, as applicable, to measure the sulfur content of gasoline they produce 

or import.

(2) Sulfur content shall be reported to the nearest ppm.

§80.1631 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 of 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 2 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.
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(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 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) 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) 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 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)(1)(iii) and (a)(1)(iv) 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 
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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.

(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.

§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 standard in 

paragraph (a)(1) or (a)(2) of this section as follows:

(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.
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(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 U.S., 

the importer must obtain a copy of the terminal test result that indicates the 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, 

as specified in this paragraph, for each truck loading terminal.

(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 International (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 truck load of imported 

gasoline as a separate batch for purposes of assigning batch numbers and maintaining records 

under §80.1653, and reporting under §80.1652.

(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.
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(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 the following requirements:

(1) All importer recordkeeping and reporting requirements under §§80.1653 and 80.1652, 

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 pergallon 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-§80.1649 [Reserved]

§80.1650 Registration.

The following registration requirements apply under this subpart:

(a) Registration with the Administrator of EPA 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.

(2) Oxygenate producer or importer having any oxygenate production facility or import 

facility subject to the oxygenate sulfur standards under §80.1610 unless already registered under 

§80.1450.

(3) Oxygenate blender who has any oxygenate blending facility that blends oxygenate 

into RBOB where the resulting gasoline is subject to the gasoline sulfur standards under this 

subpart O.

(b) Registration dates.

(1) Any gasoline refiner or importer required to register shall do so by March 31, 2013, 

or at least thirty days in advance of the first date that such person will produce or import 

reformulated gasoline, conventional gasoline, RBOB, or CBOB, whichever is later.
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(2) Any oxygenate producer or importer required to register shall do so by December 1, 

2017, or at least thirty days in advance of the first date that such person will produce or import 

oxygenate, whichever is later.

(3) Any oxygenate blender required to register shall do so by March 31, 2013, or at least 

thirty days in advance of the first date that such person will blend oxygenate into RBOB, 

whichever is later.

(c) Refiner registration.

(1) Registration shall be on forms 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, e-mail 

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) Updates to registration.

(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.
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(1) Registration shall be on forms 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) Updates to registration.

(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.

(e) Oxygenate producer registration.

(1) Registration shall be on forms 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.
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(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) Updates to registration. 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 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.

(g) Oxygenate blender registration.

(1) Registration shall be on forms 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.

(B) If records are kept off-site, the primary off-site storage facility name, physical 

location, contact name, e-mail address, and telephone number.
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(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) Updates to registration. 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.

§80.1651 Product transfer document requirements.

(a) 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) 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, and/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.”.
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(c) 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 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 information on the maximum 

recommended treatment level. 

§80.1652 Reporting requirements.

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 refiner or 

importer, and 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. 

(a) 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 (2) decimal places.

(3) The total volume of gasoline produced or imported, reported to the nearest whole 

number.

(4) The annual average sulfur level of the gasoline produced or imported, reported to two 

(2) decimal places.

(5) The annual average sulfur level after inclusion of any credits, reported to two (2) 

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.
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(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 of 

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 (2) 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 importers. From January 1, 2017 through 

December 31, 2019, importers shall report all of 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 (1) decimal place.

(c) Oxygenate producer reports. On an annual basis, the producer of DFE or other 

oxygenate must submit a summary report to EPA which includes all of the following:

(1) The facility identification information provided pursuant to §80.1650.

(2) The total volume of all batches of DFE and other oxygenate produced.
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(3) An attestation that all of the batches of DFE and other oxygenate produced during the 

compliance period were in compliance with the requirements of this subpart.

(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 or importer; and

(2) Submitted to EPA no later than the March 31 each year for the prior calendar year 

averaging period.

(e) Attest reports. Attest reports for refiner and importer attest engagements required 

under §80.1667 shall be submitted to the Administrator by May 31 of each year for the prior 

calendar year averaging period.

§80.1653 Recordkeeping.

(a) Records that must be kept. Beginning January 1, 2017 or January 1 of the first year 

that credits are generated, any person who produces, imports, sells, offers for sale, dispenses, 

distributes, supplies, offers for supply, stores, or transports gasoline, shall keep records that 

contain all of the following information:

(1) The product transfer document information required under §80.1651.

(2) All of 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 of the following information:
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(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. Information shall be kept separately for different 

types of credits 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.

(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.
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(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 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 of denatured fuel ethanol and other oxygenates must keep.

(1) The date each batch was produced.

(2) The batch volume and an identification of the test methodology used.

(3) The test results on the sulfur content of each batch and the test methodology used.

(4) The volume percent denaturant used in each batch if the oxygenate is denatured fuel 

ethanol.

(5) The type and source of the denaturant used in each batch if the oxygenate if 

denatured fuel ethanol.

(e) Records that parties that take custody of oxygenates must keep. 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) Length of time records must be kept. 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 5 years from the date the credits are 

transferred; and shall be kept by the transferee for 5 years from the date the credits were 

transferred, used, or terminated, whichever is later.

(2) Early credits.

(i) Where the party generating the credits does not transfer the credits, records must be 

kept for 5 years from the date of creation, use, or termination, whichever is later.
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(ii) Where early credits are transferred, records relating to such credits shall be kept by 

the transferor for 5 years from the date the credits are transferred; and shall be kept by the 

transferee for 5 years from the date the credits were transferred, used, or terminated, whichever is 

later.

(g) 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 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.
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(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.

(d) 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)).

(i) 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:

(A) 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

(B) The refiner provides a copy of the protocol agreement to EPA upon request.

§80.1655 National security exemptions.

(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.

(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) 
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of this section but, for national security purposes (for purposes of readiness for deployment 

oversees), 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.

§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 one of the addresses 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 of 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 of the 

following information:

(1) A concise statement of the purpose of the program demonstrating that the program 

has an appropriate research and development purpose.

(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.
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(3) All of 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.
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(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 purchaserconsumer facility is associated with the research and development program that uses the 

gasoline.

(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.
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(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) Requests for research and development exemptions shall be sent to one of the 

following addresses:

(1) For U.S. Mail: U.S. EPA—Attn: Tier 3 Program (R&D Exemption Request), 6406J, 

1200 Pennsylvania Avenue, NW., Washington, DC 20460.

(2) For overnight or courier services: U.S. EPA, Attn: Tier 3 Program (R&D Exemption 

Request), 6406J, 1310 L Street, NW., 6th floor, Washington, DC 20005.

§80.1657 [Reserved]

§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 of 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:
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(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 or oxygenate (including any denaturant) that does not 

comply with the applicable sulfur cap standards under §80.1603, §80.1604, or §80.1610.

(c) Causing an averaging or cap standard violation. Cause another person to commit an 

act in violation of paragraph (a), (b), (d), (e), (f), (g), or (h) of this section.

(d) Causing violating gasoline to be in the distribution system. Cause gasoline to be in 

the distribution system which does not comply with an applicable sulfur cap standard under 

§80.1603, §80.1604, or §80.1610. 

(e) Oxygenate violation. Starting March 1, 2017, blend into gasoline, RBOB, or CBOB 

any oxygenate, including but not limited to denatured ethanol, that has a sulfur content higher 

than 10 ppm.

(f) 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.

(g) Additive manufacturer violation. Cause or contribute to the introduction into 

commerce of a gasoline additive intended to be used at less than 1 volume percent which does 

not comply with the requirements of §80.1613.

(h) Credit violation. Generate, transfer, or use invalid credits or improperly transfer or 

use credits.

(i) Failure to meet a requirement. No person shall 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 using the methodologies specified in §§80.1630 and 80.47. Any

evidence or information, including the exclusive use of such evidence or information, may be 

used to establish the sulfur level of gasoline if the evidence or information is relevant to whether 

the sulfur level would have been in compliance with the standards if the appropriate sampling 

and testing methodology 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 §§80.1630 and 80.47, business records, and commercial documents.
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(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 under subpart O.

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, or oxygenate blender who causes another party to 

violate §80.1660(a), is liable for a violation of §80.1660(c).

(3) Cap standard violation. Any refiner, importer, distributor, reseller, carrier, retailer, 

wholesale purchaser-consumer, oxygenate producer, oxygenate blender, 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, importer, distributor, reseller, carrier, 

retailer, wholesale purchaser-consumer, oxygenate producer, oxygenate blender, 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 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, importer, 

distributor, reseller, carrier, oxygenate producer, oxygenate blender, additive manufacturer, or 

additive blender who owned, leased, operated, controlled or supervised a facility from which 

gasoline 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.
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(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) Caused 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 under subpart O.

(a) Any person deemed liable for a violation of a prohibition under §80.1662(a)(3) 

through (a)(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 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 
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or importer must show, in addition to the defense elements required under paragraphs 

(a)(1)through (a)(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, 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, 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) Quality assurance and testing program. To demonstrate an acceptable quality

assurance and testing program under paragraph (a)(2) of this section, a person must present 

evidence of all of 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 tank truck, such as appropriate 
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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 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 (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 §80.1662(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 (a)(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 noncomplying gasoline remains any place in the gasoline distribution system.

(2) Any person liable under §80.1662(a)(6) for causing gasoline 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 remains any place in the gasoline distribution system.

(3) For purposes of paragraph (c) of this section, the length of time the gasoline in 

question remained in the 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 non-complying gasoline remained in the gasoline 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.

§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 subparts O or H of this part 80; instead, the importer 
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of any foreign-produced gasoline shall be responsible for compliance with the standards and 

requirements of 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 or subpart O of this part, 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 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 SulfurFRGAS, except as provided in paragraph (c)(3) of this section. 
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(1) In the case of Certified Sulfur-FRGAS, the foreign refiner must meet the sulfur 

standards of subpart H 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 SulfurFRGAS 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 §80.1666.

(iv) The product transfer document requirements in this section and §80.1651.

(v) The prohibitions in this section and §80.1660.

(vi) The independent audit requirements under §80.415, paragraph (h) of this section, and

the attest engagement provisions of §§80.125 through 80.127, §80.128(a), (b), (c), (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 of 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.
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(2) On each occasion when any person transfers custody or title to any Sulfur-FRGAS 

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 SulfurFRGAS.

(ii) The name and EPA refinery registration number of the refinery where the SulfurFRGAS was produced.

(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 of the following requirements:

(i) The certification shall include the report of the independent third party under 

paragraph (f) of this section, and all of 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:

(1) The sulfur content as determined under paragraph (f) of this section; and

(2) A declaration that the Sulfur-FRGAS is being included in the compliance calculations 

under §80.205 for the refinery that produced the Sulfur-FRGAS.

(ii) The certification shall be made part of the product transfer documents for the SulfurFRGAS.

(e) Transfers of Sulfur-FRGAS to non-United States 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
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(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 of 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:

(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 SulfurFRGAS from the refinery to the load port, and from this review determine all of the following:

(A) The refinery at which the Sulfur-FRGAS was produced.

(B) That the Sulfur-FRGAS remained segregated from all of the following:

(1) Non-Sulfur-FRGAS and Non-Certified Sulfur-FRGAS.

(2) Other Certified Sulfur-FRGAS produced at a different refinery.
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(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 of 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 United States 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 United States port of entry, and the conditions of paragraph (g)(2)(i) of this section are 

met at the first United States port of entry, the requirements of paragraph (g)(2) of this section do 

not apply at subsequent ports of entry if the United States importer obtains a certification from 

the vessel owner, that meets the requirements of paragraph (r) of this section, that the vessel has 

not loaded any gasoline or blendstock between the first United States port of entry and the 

subsequent port of entry.

(2)(i) The requirements of this paragraph (g)(2) apply if:

(A) The temperature-corrected volumes determined at the port of entry and at the load 

port differ by more than one percent; or

(B) 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 International (ASTM).
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(ii) The United States importer and the foreign refiner shall treat the gasoline as NonCertified Sulfur-FRGAS, and the foreign refiner shall exclude the gasoline volume and 

properties from its gasoline sulfur compliance calculations under §80.205.

(h) Attest requirements. All of 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 of the following:

(i) Obtain the report of the independent third party, under paragraph (f) of this section, 

and of the United States 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 SulfurFRGAS 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 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-Sulfur-FRGAS, or any Certified Sulfur-FRGAS produced at a different 

refinery.
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(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 United States importer reports to the information contained in the commercial 

document.

(6) Obtain separate listings of all tenders of Non-Sulfur-FRGAS, and perform all of 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 paragraph (h)(6) of this section 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 paragraph (h) of this 

section 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 provisions contained in this paragraph (i) as a condition to being approved for small refiner 

status or small volume refinery status.

(1) Any United States Environmental Protection Agency inspector or auditor will be 

given full, complete and immediate access to conduct inspections and audits of the foreign 

refinery.
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(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;

(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 of 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 SulfurFRGAS, 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.
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(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 of process located in the District of Columbia will be named, and 

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) United States substantive and procedural laws 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. section 1605(a)(2), but solely 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 Title 18 U.S.C. section 1001 or Clean Air Act section 113(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 Sulfur-FRGAS 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 
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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 Title 18 U.S.C. section 1001 or Clean Air Act section 113(c)(2).

(k) Bond posting. Any foreign refiner must meet the requirements of this paragraph (k) 

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 United States administrative or judicial judgments against the foreign refiner, 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 Title 18 U.S.C. section 1001 and Clean Air Act section 113(c)(2);

(ii) Be provided by a corporate surety that is listed in the United States 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, 
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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 (5) 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 Non-Certified SulfurFRGAS 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) United States importer requirements. Any United States importer shall meet the 

following requirements:

(1) Each batch of imported gasoline shall be classified by the importer as being SulfurFRGAS 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.

(2) Gasoline shall be classified as Certified Sulfur-FRGAS or as Non-Certified SulfurFRGAS 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 Sulfur-FRGAS under paragraph (g) of 

this section.

(3) For each gasoline batch classified as Sulfur-FRGAS, any United States 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.
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(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 Sulfur-FRGAS.

(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 United States 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 United States 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:

(1) The third party analyzing the sample; or

(2) 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 United States 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 United States importer shall meet the applicable requirements of 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 of 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.
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(iii) Attest under paragraph (h) of this section.

(iv) Importer testing under paragraph (n)(3) of this section.

(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 of 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 United States 

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.
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(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:

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 Title 18, United States Code, section 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, and 80.1666, 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. 
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(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.

(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.
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(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

(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.

§§80.1668-80.1674 [Reserved]
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§80.1675 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, the Environmental Protection Agency (EPA) 

must publish notice of change in the Federal Register and the material must be available to the 

public. All approved material is 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. This 

material is also available for inspection at the EPA Docket Center, Docket No. EPA–HQ–OAR–

2005–0161, EPA/DC, EPA West, Room 3334, 1301 Constitution Ave., NW., Washington DC. 

The telephone number for the Air Docket is (202) 566–1742. Also, this material is available 

from the source listed in paragraph (b) of this section.

(b) ASTM International, 100 Barr Harbor Drive, P.O. Box C–700, West Conshohocken, 

Pennsylvania 19428 (1–800–262–1373, www.astm.org ).

(1) ASTM D 4814–11 (“ASTM D 4814”), Standard Specification for Automotive SparkIgnition Engine Fuel, Approved 2011; IBR approved for §80.177.

(2) ASTM D 4057–95 (“ASTM D 4507”), Approved 1995; IBR approved for §80.1630.

(3) ASTM D 4177–95 (“ASTM D 4177”), Approved 1995; IBR approved for §80.1630.

(4) ASTM D 5842–95 (“ASTM D 5842”), Approved 1995; IBR approved for §80.1630.
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PART 85— CONTROL OF AIR POLLUTION FROM MOBILE SOURCES

1. The authority citation for part 85 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart F—[Amended]

2. 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 86 when 

operating on the alternative fuel.

* * * * *

3. Section 85.515 is amended by revising paragraph (b)(9)(iii) to read as follows:

§ 85.515 Exemption provisions for intermediate age vehicles/engines.

* * * * *
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(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 86 when 

operating on the alternative fuel.

* * * * *

4. 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 86 when 

operating on the alternative fuel.

* * * * *

Subpart P—[Amended]

5. Section 85.1515 is revised to read as follows:
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§ 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:

(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:
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(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
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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, 

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 
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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 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 through 

86.1816.

(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 
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Page 549 of 995

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.

(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 
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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

P Year

Hy

drocarbon

C

arbon

monoxide

xides of

nitrogen

Die

sel 

Particulate

Evapo

rative 

hydrocarbon

Useful life

(years/miles)

968–76

1.5 

gpm

1

5 gpm .1 gpm

6.0 

g/test 5/50,000

977–79

1.5 

gpm

1

5 gpm .0 gpm

6.0 

g/test 5/50,000

980

0.4

1 gpm

7

.0 gpm .0 gpm

6.0 

g/test 5/50,000

981

0.4

1 gpm

3

.4 gpm .0 gpm

2.0 

g/test 5/50,000

982–86

0.4

1 gpm

3

.4 gpm .0 gpm

0.6

0 gpm

2.0 

g/test 5/50,000

987–93

0.4

1 gpm

3

.4 gpm .0 gpm

0.2

0 gpm

2.0 

g/test 5/50,000

994 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.
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Page 552 of 995

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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Page 553 of 995

Table 2—Emission Standards Applicable to Imported Light-Duty Trucks1,2,3,4,5

P year

Hy

drocarbon

C

arbon 

monoxide

O

xides of 

nitrogen

Di

esel 

Particulate

Evaporativ

e hydrocarbon

Useful life

(years/miles)

968–

78

2.0 

gpm

2

0 gpm

3

.1 gpm 6.0 g/test 5/50,000

979–

80

1.7 

gpm

1

8 gpm

2

.3 gpm 6.0 g/test 5/50,000

981

1.7 

gpm

1

8 gpm

2

.3 gpm 2.0 g/test 5/50,000

982–

83

1.7 

gpm

(2.0)

1

8 gpm

(26)

2

.3 gpm

(2.3)

0.

60 gpm

(0.60)

2.0 g/test

(2.6) 5/50,000

984

0.8

0 gpm

(1.0)

1

0 gpm

(14)

2

.3 gpm

(2.3)

0.

60 gpm

(0.60)

2.0 g/test

(2.6) 5/50,000

985–

86

0.8

0 gpm

(1.0)

1

0 gpm

(14)

2

.3 gpm

(2.3)

0.

60 gpm

(0.60)

2.0 g/test

(2.6) 11/120,000

987

0.8

0 gpm

(1.0)

1

0 gpm

(14)

2

.3 gpm

(2.3)

0.

26 gpm

(0.26)

2.0 g/test

(2.6) 11/120,000

988–

0.8

0 gpm

1

0 gpm

1

.2 gpm6

0.

26 gpm7

2.0 g/test

(2.6) 11/120,000
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89 (1.0) (14) (1.2) (2.0)

0.8

0 gpm

(1.0)

1

0 gpm

(14)

1

.7 gpm6

(1.7)

0.

45 gpm7

(0.26)

2.0 g/test

(2.6) 11/120,000

0.8

0 gpm

(1.0)

1

0 gpm

(14)

2

.3 gpm6

(2.3)

0.

45 gpm7

(0.26)

2.0 g/test

(2.6) 11/120,000

990–

93

0.8

0 gpm

(1.0)

1

0 gpm

(14)

1

.2 gpm8

(1.2)

0.

26 gpm7

(0.26)

2.0 g/test

(2.6) 11/120,000

0.8

0 gpm

(1.0)

1

0 gpm

(14)

1

.7 gpm8

(1.7)

0.

45 gpm7

(0.26)

2.0 g/test

(2.6) 11/120,000

994 

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 highaltitude 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.
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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.

9

Specified in 40 CFR part 86 for the OP year of the vehicle, as described in paragraph (c) of this section.

Subpart W—[Amended]

6. Subpart W, consisting of §§ 85.2201, 85.2207, 85.2222, 85.2223, and 85.2231, is revised to 

read as follows:

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.

7. Section 85.2201 is revised to read as follows:

§ 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.
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8. Section 85.2207 is revised to read as follows:

§ 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. 

9. Section 85.2222 is revised to read as follows:

i. § 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.

(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 
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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.

10. Section 85.2223 is revised to read as follows:

§ 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 fault code, 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.

11. Section 85.2231 is revised to read as follows:

ii. § 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.
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(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

12. The authority citation for part 86 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

13. Section 86.1 is amended by revising paragraphs (d) and (g)(2) to read as follows:

§ 86.1 Reference materials.

* * * * *

(d) California Air Resources Board, 1001 I Street, Sacramento, CA, 95812, (916) 322–

2884, http://www.arb.ca.gov.

(1) California Requirements Applicable to the LEV III Program, Title 13, §1961.2 and 

§1976(b)1)(G) of the California Code of Regulations, approved on March 22, 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 and 86.612–97.

(3) California Regulatory Requirements known as On-board 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.

(4) California Regulatory Requirements known as On-board 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 
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Passenger Cars, Light-Duty Trucks, and Medium-Duty Vehicles and Engines (OBD–II), IBR 

approved for §§ 86.007–17, 86.1806–05.

(5) California Regulatory Requirements known as On-board Diagnostics II (OBD-II), 

Approved on June 17, 2010, 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 § 86.1806-17.

* * * * *

(g) * * *

(2) SAE J1634, Revised October 2012, Battery Electric Vehicle Energy Consumption 

and Range Test Procedure, IBR approved for § 86.1811-04(n).

* * * * *

Subpart A—[Amended]

§§86.000-8, 86.000-9, 86.000-16, 86.000-26, 86.000-28, 86.001-9, 86.001-22, 86.001-25, 

86.001-26, 86.001-28, 86.001-30, 86.004-9, 86.007-38, 86.079-36, 86.085-20, 86.087-2, 86.094-

13, 86.094-16, 86.094-26, 86.094-28, 86.095-23, 86.095-26, 86.095-30, 86.096-7, 86.096-8, 

86.096-21, 86.096-26, 86.096-30, 86.096-35, 86.096-38, 86.097-9, 86.098-24, 86.098-25, 

86.098-26, 86.098-28, 86.098-30, 86.098-35, 86.099-8, 86.099-9, 86.099-17 – [Removed]

14. Subpart A is amended by removing the following sections: §§86.000-8, 86.000-9, 86.000-

16, 86.000-26, 86.000-28, 86.001-9, 86.001-22, 86.001-25, 86.001-26, 86.001-28, 86.001-30, 

86.004-9 , 86.007-38, 86.079-36, 86.085-20, 86.087-2, 86.094-13, 86.094-16, 86.094-26, 

86.094-28, 86.095-23, 86.095-26, 86.095-30, 86.096-7, 86.096-8, 86.096-21, 86.096-26, 

86.096-30, 86.096-35, 86.096-38, 86.097-9, 86.098-24, 86.098-25, 86.098-26, 86.098-28, 

86.098-30, 86.098-35, 86.099-8, 86.099-9, 86.099-17.

15. 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.
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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.

* * * * *

§86.000-24—[Amended]

16. Section 86.000-24 is amended as follows:

a. By removing the introductory text.

b. By removing and reserving paragraph (a).

c. By removing paragraphs (b) introductory text and (b)(1) introductory text.

d. By removing paragraphs (b)(1)(iii) through (b)(1)(xii).

e. By removing and reserving paragraph (b)(2).

f. By removing paragraph (b)(3).

g. By removing paragraphs (c) through (f).

h. By removing paragraph (g) introductory text.

i. By removing and reserving paragraphs (g)(1) and (g)(2).

j. By removing paragraph (h).

17. Section 86.001-23 is amended by revising the introductory text and paragraph (c) 

introductory text and removing and reserving paragraphs (c)(1), (f), and (g) to read as 

follows:

§ 86.001-23 Required data.

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 —
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* * * * *

18. 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.”

* * * * *

§86.004-25—[Amended]

19. Section 86.004-25 is amended by removing and reserving paragraph (b)(4)(ii) and 

(b)(4)(iv).

20. 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 
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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 data 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]

21. Section 86.004-28 is amended by removing the introductory text and by removing and 

reserving paragraphs (a), (b), (f), and (g).

22. 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).

c. By removing paragraphs (a)(19) through (a)(21).

d. By removing and reserving paragraph (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.
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Section 86.004–30 includes text that specifies requirements that differ from §86.094–30. 

Where a paragraph in §86.094–30is 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.”

23. 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).”

24. 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.

* * * * *

25. Section 86.007-17 is revised to read as follows:
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§ 86.007-17 On-board diagnostics for engines used in applications less than or 

equal to 14,000 pounds GVWR.

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 on-board diagnostic 

requirements as specified in §86.1806-17(a), (c), and (d).

§86.007-21—[Amended]

26. 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).

27. 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.”.

* * * * *

(b) * * *

(2) [Reserved]

* * * * *

(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:
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(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 gaseousfueled 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. 

* * * * *

(f) through (g) [Reserved]

* * * * *

(l) [Reserved]

* * * * *

§86.007-30—[Amended]

28. Section 86.007-30 is amended as follows:

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).

29. 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)
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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 2007through 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”.

* * * * *

30. Section 86.008-10 is amended by removing the introductory text and revising paragraphs 

(b) introductory text and (e) to read as follows:

§86.008-10 Emission standards for 2008 and later model year Otto-cycle heavyduty engines and vehicles.

* * * * *

(b) This paragraph (b) applies through model year 2013. See 40 CFR 1037.103 for 

provisions that apply in 2014 and later model years. 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 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.

* * * * *
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(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.

* * * * *

31. Section 86.010-38 is amended by revising paragraphs (g) and (i) to read as follows:

§ 86.010-38 Maintenance instructions.

* * * * *

(g) Emission control diagnostic service information. Manufacturers are subject to the 

requirements of §86.1808-01(f) beginning in the 2005 model year for manufacturers of heavyduty vehicles and heavy-duty 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).”

* * * * *

32. 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 
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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. 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 

diesel-cycle and Otto-cycle heavy-duty engines installed in vehicles above 14,000 pounds 

GVWR. 

(2) The provisions of this subpart related to exhaust emission standards apply as 

follows for engines that will be installed in incomplete vehicles at or below 14,000 pounds 

GVWR:

(i) These provisions apply for diesel-cycle engines.

(ii) These provisions are optional for Otto-cycle engines.

(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 

diesel-cycle engines installed in such vehicles through model year 2018.

(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 complete vehicles at or below 14,000 pounds

GVWR.

(ii) Vehicles above 14,000 pounds GVWR and all sizes of incomplete heavy-duty 

vehicles must meet evaporative emission standards as specified in §86.008-10 through 

model year 2017, and as specified in 40 CFR part 1037 in later model years.

(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 dieselcycle and Otto-cycle heavy-duty engines and vehicles as follows:
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(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 may

optionally comply with the onboard diagnostic requirements specified in §86.007-17, in 

which case those vehicles are not subject to separate onboard diagnostic requirements 

under this part.

(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.

(h) Turbine engines. Turbine engines are deemed to be compression-ignition engines for 

purposes of this part.

33. 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. 
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* * * * *

§86.085-37—[Amended]

34. Section 86.085-37 is amended by removing paragraph (b) and the Effective Date Note and 

the end of the section.

§86.091-29—[Amended]

35. Section 86.091-29 is amended by removing and reserving paragraph (a).

36. Section 86.094-7 is amended as follows:

a. By removing and reserving paragraph (h)(1).

b. By revising paragraph (h)(6).

c. By removing paragraph (h)(7).

§ 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.

* * * * *

§86.094-14—[Amended]

37. Section 86.094-14 is amended by removing and reserving paragraphs (c)(5) and 

(c)(7)(i)(A)(1).

§86.094-21—[Amended]
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38. 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]

39. Section 86.094-25 is amended as follows:

a. By removing and reserving paragraphs (a), (b)(3)(i)(A), (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).

§86.094-30—[Amended]

40. 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).

d. By removing and reserving paragraph (d).

41. 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 through model year 2013. See 40 CFR part 1037 for 

provisions that apply in 2014 and later model years. 

* * * * *
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(d) – (f) [Reserved]

(g) Incomplete vehicle fuel tank capacity. This paragraph (g) applies through model year 

2013. See 40 CFR part 1037 for provisions that apply in 2014 and later model years. 

* * * * *

§86.096-24—[Amended]

42. 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).

§86.098-23—[Amended]

43. Section 86.098-23 is amended by removing and reserving paragraphs (b)(1)(i), (e)(2), and 

(e)(3). 

Subpart B—[Amended]

44. Section 86.102 is revised to read as follows:

§ 86.102 Definitions.

The definitions in §86.1803 apply to this subpart.

§§ 86.106-00, 86.108-79, 86.110-90, 86.111-90, 86.115-00, 86.118-78, 86.127-96, 

86.128-00, 86.130-00, 86.131-00, 86.135-00, 86.135-94, 86.137-90, 86.137-96, 86.162-00, 

86.167-17 – [Removed]
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45. Subpart B is amended by removing the following sections: §§ 86.106-00, 86.108-79, 

86.110-90, 86.111-90, 86.115-00, 86.118-78, 86.127-96, 86.128-00, 86.130-00, 86.131-00, 

86.135-00, 86.135-94, 86.137-90, 86.137-96, 86.162-00, 86.167-17.

46. 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 are 

deemed to 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) 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.

(6) 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, calibrate your evaporative emission enclosure with 

ethanol and propane. 

(b) Migration to 40 CFR part 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. For any EPA testing before model year 2022, EPA will 

use the manufacturer's selected procedures for determining road load parameters and 
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applying cycle-verification criteria. For any other parameters, EPA may conduct testing 

using either of the 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, verify overall driver accuracy based on driven cycle energy and 

report information as described in 40 CFR 1066.430(j).

(ii) The equipment specifications and measurement procedures related 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.

(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 1066.840.

(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 this subpart and in 40 CFR parts 

1065 and 1066 as follows:

(1) Use fuel for testing and service accumulation as specified in §86.113.

(2) For exhaust emission testing, measure emissions for all pollutants with an 

applicable emission standard. Calculate emission results as described in 40 CFR part 1066, 

subpart G.
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(3) 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.

(4) 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.

(v) Test fuel systems for leaks as described in 40 CFR 1066.840.

(5) Keep records as described in §86.142

(6) Perform refueling emission tests, calculate emission results, and keep associated 

records as described in §86.146 through 86.157.

47. 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]

48. Section 86.107-96 is amended by removing paragraph (e). 
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49. Section 86.110-94 is amended by revising paragraph (d) to read as follows:

§ 86.110-94 Exhaust gas sampling system; diesel-cycle vehicles, and Otto-cycle 

vehicles requiring particulate emissions measurements.

* * * * *

(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:

(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). 

§86.113-94—[Amended]

50. Section 86.113-94 is amended by removing and reserving paragraph (a). 

51. Section 86.113-04 is amended by revising paragraphs (a)(2) and (a)(3)(i) to read as follows:

§ 86.113-04 Fuel specifications.

* * * * *
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(a) * * *

(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 certification confirmatory testing, selective enforcement auditing and in-use 

testing.

(ii) For model year 2015 and later, manufacturers may certify 50-state vehicles based on 

testing used to meet California’s LEV III standards, including the use of California Phase 3 

gasoline (E10), subject to the following provisions:

(A) The Administrator will also use this E10 fuel for any testing to confirm that vehicles 

meet the LEV III standards. Note that all evaporative testing with the E10 fuel must be 

conducted with temperatures meeting the specifications adopted by the California Air 

Resources Board.

(B) The manufacturer must also use this E10 fuel for fuel economy measurements, with 

any appropriate corrections related to ethanol content in the fuel.

(C) The vehicles must also meet standards at high-altitude conditions. The high-altitude 

standards for a given vehicle are the LEV III standards that apply for low-altitude testing, 

except that testing is based on the fuel specified in paragraph (a)(1) of this section. Note 

that heavy-duty vehicles certified under this paragraph (a)(2)(ii)(C) are not subject to 

SFTP standards at high-altitude conditions. Manufacturers may alternatively use the E15 

test fuel specified in §86.113-07 for high-altitude testing.

(D) The vehicle must meet the applicable cold-temperature standards using the fuel 

specified in paragraph (a)(1) of this section.

(E) Such vehicles are considered to be Tier 2 vehicles for EPA certification; however, 

manufacturers must exclude them from the fleet-average NOx calculation in subpart S of 

this part.

(3) * * *

(i) Unless 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. 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) . Leaded gasoline must not be used in service 

accumulation.

* * * * *

52. Section 86.113-07 is amended by revising the introductory text and paragraph (a) to read as 

follows:

§86.113-07 Fuel specifications.
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Section 86.113–07 includes text that specifies requirements that differ from §86.113–94. 

Where a paragraph in §86.113–94 is identical and applicable to §86.113–07, 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. Manufacturers must certify

using service accumulation fuel and E15 test fuel as specified in 40 CFR 1065, subpart H, on the 

following schedule:

(1) Use the E15 test fuel to demonstrate compliance with the Tier 3 evaporative 

emission standards as specified in §86.1813. Use the E15 test fuel to demonstrate 

compliance with the Tier 3 exhaust emission standards as specified in §86.1811 and 86.1816. 

Where testing with E15 test fuel is required, this applies for all testing for demonstrating 

compliance with exhaust emission standards and fuel economy requirements. For vehicles 

certified for 50-state sale through model year 2019, you may instead use California Phase 3 

gasoline (E10) as adopted in California’s LEV III program for exhaust and evaporative 

emission testing at low-altitude conditions; the Administrator will also use this E10 fuel for 

any low-altitude testing with such vehicles. In the case of evaporative emission tests with 

California Phase 3 gasoline, perform tests based on the temperatures specified by the 

California Air Resources Board.

(2) Use the E15 test fuel to demonstrate compliance with the evaporative emission 

standards specified in §86.1811-10 starting in model year 2020. You may not certify these 

vehicles using carryover data based on measurements with E0 test fuel.

(3) Use the E15 test fuel to demonstrate compliance with the refueling emission 

standards for any vehicles that must be certified to meet the diurnal plus hot soak standards 

with E15 test fuel under paragraph (a)(1) of this section. 

(4) For any vehicles that require testing to demonstrate compliance with the refueling 

spitback standard, use the E15 test fuel starting in model year 2022.

(5) If a vehicle uses E15 test fuel for evaporative emission testing and E0 or E10 is 

the applicable test fuel for exhaust emission testing, or vice versa, 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. 

(6) Use service accumulation fuel as described in 40 CFR part 1065, subpart H, with 

the additional provisions specified in §86.113-04(a)(3).
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* * * * *

53. 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:

* * * * *

54. Section 86.117-96 is amended by revising the introductory text and paragraphs (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. 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) * * *

(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 
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±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 ±5 percent of that measured in 

paragraph (c)(1)(vii) of this section. 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.

* * * * *

55. 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]

56. Section 86.129-80 is amended by removing and reserving paragraph (a). 

57. Section 86.130-96 is amended by revising the introductory text and 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.

* * * * *

(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 
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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.

58. 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. The emission standards do 

not apply when any of these AECDs are active.

§86.132-96—[Amended]

59. Section 86.132-96 is amended by removing and reserving paragraph (k). 

60. Section 86.133-96 is amended by adding paragraph (a)(4) to read as follows:

§ 86.133-96 Diurnal emission test.

(a) * * *

(4) Manufacturers may use a pressurized fuel system if they demonstrate that fuel vapor 

would not be vented to the atmosphere if there is a leak in the fuel system or if the fuel cap is 
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removed. Without this demonstration, tank pressure must not exceed 10 inches of water during 

the diurnal emission test. 

* * * * *

61. Section 86.134-96 is amended by revising paragraph (g)(1)(xvi) and adding paragraph (g)(4) 

to read as follows:

§ 86.134-96 Running loss test.

* * * * *

(g) * * *

(1) * * *

(xvi) Manufacturers may use a pressurized fuel system if they demonstrate that fuel vapor 

would not be vented to the atmosphere if there is a leak in the fuel system or if the fuel cap is 

removed. Without this demonstration, 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. 

* * * * *

(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.

* * * * *

62. 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 
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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. 

* * * * *

(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.

* * * * *

63. 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.

* * * * *
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(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.

(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.
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(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.

64. 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 1066.430 for each drive cycle 

or test phase, as appropriate. 

* * * * *

65. 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, use the 

following equation to calculate a hydrocarbon equivalent mass for comparing to the standard:

THCE HC

i

14.3 in

M m

MW



 

Where:

MTHCE = the C1-equivalent sum of the concentration of carbon mass contributions of nonoxygenated hydrocarbons, alcohols, and aldehydes.

mHC = the mass contribution from nonoxygenated hydrocarbons.

ni = the number of carbon atoms in the molecular representation of the oxygenated 
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emission component i. For example, for methanol (CH3OH), n = 1 and for ethanol (C2H5OH), n 

= 2.

MWi = the molecular weight of the oxygenated emission component i, as described in 40 

CFR 1065.1005.

* * * * *

Subpart C – [Amended]

66. Subpart C, consisting of §§ 86.201 and 86.213, is revised to read as follows:

Sec.

86.201 General applicability.

86.213 Fuel specifications.

§ 86.201 General applicability.

(a) Vehicles are subject to cold-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) Manufacturers may certify vehicles using carryover data based on previously

published cold-testing procedures. In addition, we may approve the use of previously published 

cold-testing procedures as an alternative procedure under 40 CFR 1066.10(c).

(c) 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 E15 test fuel as specified in 

§86.113 for any vehicles required to use an ethanol-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 Regul

ar

Premi

um1

Refere

nce Procedure2

(RON+MON)/23 87.8±0

.3

92.3±

0.5 AST

M D2699

Sensitivity37.5 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

AST

M D86

Hydrocarbon 

composition (vol %):

 Olefins

 Aromatics

12.5±0

.5

26.4±4

.0

Remai

10.5±

0.5

32.0±

4.0

Rema

AST

M D1319
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 Saturates nder inder

Lead, g/gallon 0.01, 

Maximum

0.01, 

Maximum

AST

M D3237

Phosphorous, g/gallon 0.005 

Maximum

0.005 

Maximum

AST

M D3231

Total sulfur, wt. % 0.0015 

– 0.008

0.001

5 – 0.0084

AST

M D3120

RVP, psi 11.5±0

.3

11.5±

0.3

AST

M D4953

1 The premium fuel specifications apply for vehicles designed to use high-octane premium fuel.

2 ASTM procedures are incorporated by reference in §86.1.

3 Octane specifications are optional for manufacturer testing.

4

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 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]
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67. Subpart D is removed.

Subpart F—[Amended]

§ 86.505-78 – [Removed]

68. Subpart F is amended by removing § 86.505-78.

§86.513-94—[Amended]

69. Section 86.513-94 is amended by removing and reserving paragraph (a) and by removing 

paragraphs (e) and (f). 

70. 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 
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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 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]

71. 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 
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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.

(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 nonintegrated 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.
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(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.

(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).
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(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 manufacturer shall perform corrective 
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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. 

* * * * *

72. 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 §86.146–96. Accordingly, for the fuel dispensing 

spitback test, the term “final deteriorated test results” means the final test results derived in 
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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]

73. Section 86.610-98 is amended by removing and reserving paragraph (c)(2).

74. Section 86.612-97 is revised to read as follows: 

§ 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.
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(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 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:
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(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 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 
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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]

75. Subpart H, consisting of §§ 86.701-94 through 86.709-99, is removed.

Subpart M—[Removed]

76. Subpart M is removed.

Subpart N--Exhaust Test Procedures for Heavy-duty Engines

77. The subpart heading is revised as set forth above. 

Subpart N—[Amended]

§§ 86.1301, 86.1302-84, 86.1303-84, 86.1304, 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, 86.1332-90, 

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, 86.1344-94, 86.1362-2007, 86.1363-2007, 86.1375-2007, 86.1380-

2004 – [Removed]

78. Subpart N is amended by removing the following sections: §§ 86.1301, 86.1302-84, 

86.1303-84, 86.1304, 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, 86.1332-90, 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, 
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86.1340-90, 86.1340-94, 86.1341-90, 86.1341-98, 86.1342-90, 86.1342-94, 86.1343-88, 

86.1344-94, 86.1362-2007, 86.1363-2007, 86.1375-2007, 86.1380-2004.

§§ 86.1305-2010, 86.1333-2010, 86.1360-2007, 86.1362-2010, 86.1370-2007, 86.1372-

2007—[Redesignated as §§ 86.1305, 86.1333, 86.1360, 86.1362, 86.1370, 86.1372]

79. Redesignate specific sections in subpart N as follows: 

old section new 

section

86.1305-

2010

86.1305

86.1333-

2010

86.1333

86.1360-

2007

86.1360

86.1362-

2010

86.1362

86.1370-

2007

86.1370

86.1372-

2007

86.1372

80. Newly redesignated § 86.1305 is revised to read as follows:

§ 86.1305 Introduction; structure of subpart.
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(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 E0 fuel specified in 40 CFR part 

1065, except that the sulfur concentration must be between 0.0015 and 0.008 weight percent and 

research octane must be at least 93.

(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.

(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.
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81. Newly redesignated § 86.1333 is amended by revising paragraphs (a)(1) 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.

* * * * *

(d) Determine idle speeds as specified in 40 CFR 1065.510.

82. 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.
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* * * * *

(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.

* * * * *

83. Newly redesignated § 86.1362 is amended by revising the introductory text and adding 

paragraph (f) to read as follows:
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§ 86.1362 Steady-state testing with a ramped-modal cycle.

This section describes how to test engines under steady-state conditions. 

* * * * *

(f) For 2007 through 2010 model years, manufacturers may follow the mode order 

described in this paragraph (f) 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
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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 20 C Linear 
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Transition 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.

84. 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-ToExceed 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 are considered valid Not-To-Exceed tests (Note:

duty cycles and limits on ambient conditions do not apply for Not-To-Exceed tests).
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(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 

operation conditions.

* * * * *

Subpart O—[Removed]

85. Subpart O, consisting of §§ 86.1401 through 86.1442, is removed.
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Subpart R—[Removed]

86. Subpart R, consisting of §§ 86.1701-99 through 86.1780-99, is removed.

Subpart S – [Amended]

§§86.1805-01, 86.1806-01, 86.1806-04, 86.1808-07, 86.1811-01, 86.1812-01, 86.1813-

01, 86.1814-01, 86.1814-02, 86.1815-01, 86.1815-02, 86.1845-01 – [Removed]

87. Subpart S is amended by removing the following sections: §§ 86.1805-01, 86.1806-01, 

86.1806-04, 86.1808-07, 86.1811-01, 86.1812-01, 86.1813-01, 86.1814-01, 86.1814-02, 

86.1815-01, 86.1815-02, 86.1845-01.

88. Section 86.1801-12 is amended by revising paragraphs (a) through (e) 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. 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. 

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 2018.

(ii) The onboard diagnostic requirements in this subpart do not apply if engines 

meet the onboard diagnostic requirements specified in §86.007-17.
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(iii) 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) Incomplete heavy-duty vehicles at or below 14,000 pounds GVWR may be 

optionally certified to the exhaust emission standards in this subpart that apply for 

complete heavy-duty vehicles.

(ii) The evaporative and refueling emission standards apply for incomplete heavyduty vehicles at or below 14,000 pounds GVWR starting with model year 2018. 

Evaporative emission standards also apply for vehicles above 14,000 pounds GVWR as 

specified in 40 CFR part 1037.

(iii) The onboard diagnostic requirements in this subpart do not apply for vehicles 

above 14,000 pounds GVWR; these requirements apply for incomplete vehicles at or 

below 14,000 pounds GVWR only if the installed engine does not meet the onboard 

diagnostic requirements specified in §86.007-17.

(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.

* * * * *
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89. 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 revising the definitions for “Family emission limit”, “Heavy-duty vehicle”, and 

“Hybrid electric vehicle (HEV)”.

d. By adding definitions for “LEV III” and “Low-altitude conditions” in alphabetical 

order.

e. By removing the definition for “Low altitude conditions”.

f. By adding a definition for “Rated power” in alphabetical order.

g. By revising the definition for “Round, rounded or rounding”.

h. By adding definitions for “Section 177 states”, “Tier 3”, and “United States” in 

alphabetical order.

i. By revising the definition for “U.S. sales”.

j. 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.

* * * * *

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 
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using consumable fuel, and a rechargeable energy storage system such as a battery, capacitor, 

hydraulic accumulator, or flywheel.

* * * * *

LEV III means relating to the LEV III emission standards in Title 13, §§1961.2 and 

1976(b)1)(G) 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).

* * * * *

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 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. 
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* * * * *

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.

* * * * *

90. 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.

(b) Greenhouse gas pollutants. The emission standards in §86.1818 apply for a useful life 

of 10 years or 120,000 miles for LDVs and LLDTs and 11 years or 120,000 miles for HLDTs, 

MDPVs, and heavy-duty vehicles. Manufacturers may alternatively certify based on a longer 

useful life as specified in paragraph (c) of this section.

(c) Criteria pollutants. The useful life provisions of this paragraph (c) apply for all 

emission standards not covered by paragraph (b) of this section. Except as specified in 

paragraph (e) of this section and in §§ 86.1811, 86.1813, and 86.1816, the useful life for LDT2s, 

HLDTs, MDPVs, and HDVs 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 LDVs and LDT1s 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. LDVs and LDT1s certified to the longer useful life are subject to 

higher numerical FTP emission standard for NMOG+NOx as specified in §86.1811-17(b).

(d) Intermediate useful life. Where exhaust emission standards are specified for an 

intermediate useful life, these standards apply for five years or 50,000 miles.
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(e) 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.

28. Section 86.1806-05 is amended by revising paragraphs (b) introductory text and (j) 

and adding paragraph (k)(7) to read as follows: 

§ 86.1806-05 On-board diagnostics for vehicles less than or equal to 14,000 pounds 

GVWR.

* * * * *

(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 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.

* * * * *

(j) California OBDII compliance option. Manufacturers may comply with California’s 

OBD requirements instead of meeting the requirements of this section as follows:

(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
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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 2010 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)(A) Diesel. 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.
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(B) If monitored for performance—a particulate trap is replaced with a trap that has 

catastrophically failed.

(iii) (A) Otto-cycle. An engine misfire condition is induced that completely disables one 

or more cylinders, either through mechanical or electrical means, resulting in 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 on-board 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 

on-board computer, or renders the entire on-board 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.
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* * * * *

91. A new § 86.1806-17 is added to subpart S to read as follows:

§ 86.1806-17 On-board 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 fault codes corresponding to detected malfunctions, and alert operators 

appropriately.

(a) Vehicles must comply with the 2010 OBD requirements adopted for California as 

described in this paragraph (a). California’s 2010 OBD requirements are part of Title 13, 

§1968.2 of the California Code of Regulations, approved on June 17, 2010 (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).
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(b) The following additional provisions apply:

(1) OBD systems must record in computer memory the result of the most recent 

successfully completed diagnostic check for a 0.020 inch leak. The required data records 

include the miles driven since the last check occurred and the pass/fail result. The system 

may be designed to keep data only from the previous 750 miles of driving. The leak check 

results must be scan readable, and must be retained in system memory even if codes are 

cleared or the vehicle loses battery power.

(2) For every family selected for making the full OBD demonstration for certification, 

that demonstration must also include a test showing that the OBD system is capable of 

detecting an implanted 0.020 inch leak in the fuel system. Manufacturers may separately 

perform this test with any number of additional families. For any untested families, the 

statement specified in §86.1844-01(d)(8) applies with regard to this leak monitoring 

requirement. 

(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 compliance and show that the necessary hardware or software modifications would 

pose an unreasonable burden. 
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(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. 

§86.1807-01—[Reserved]

28. Section 86.1807-01 is amended by removing and reserving paragraph (a)(3)(ix). 

92. 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) 

beginning in the 1996 model year for manufacturers of light-duty vehicles and light-duty trucks, 

and beginning in the 2005 model year for manufacturers of heavy-duty vehicles and heavy-duty 

engines weighing 14,000 pounds gross vehicle weight (GVW) and less that are subject to the 

OBD requirements of this part.

* * * * *

(3) Information dissemination. By December 24, 2003, 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 World Wide Web site containing the information 

specified in paragraph (f)(2)(i) of this section for 1996 and later model year vehicles which 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. Upon request and 

approval of the Administrator, manufacturers who can demonstrate significant hardship in 
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complying with this provision within four months after the effective date may request an 

additional six months lead time to meet this requirement. Each manufacturer Web site 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 Web site an index of all emissions-related training 

information available for purchase by aftermarket service providers for 1994 and newer vehicles. 

For model years subsequent to 2003, 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 Web site. 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 
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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.

* * * * *

(13) Generic and enhanced information for scan tools. By September 25, 2003, 

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 Web sites 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. This 

information shall be made available to equipment and tool companies no later than September 

23, 2003.

* * * * *

(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).”

93. Section 86.1810-01 is amended by removing paragraph (m) and revising paragraph (f)(1) to 

read as follows:

§ 86.1810-01 General standards; increase in emissions; unsafe condition; waivers.

* * * * *
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(f) Altitude requirements. (1) Unless otherwise specified, emission standards apply at 

low-altitude conditions and at high-altitude conditions. The following exceptions apply:

(i) The supplemental exhaust emission standards as described in § 86.1811–04(f) apply 

only at low-altitude conditions;

(ii) The cold temperature NMHC emission standards as described in § 86.1811–10(g) 

apply only at low-altitude conditions;

(iii) The evaporative emission standards specified in § 86.1811-09(e) apply at lowaltitude 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. 

* * * * *

94. A new §86.1810-17 is added to subpart S to read as follows:

§ 86.1810-17 General standards; increase in emissions; unsafe condition; waivers.

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 emissionrelated components are designed to operate properly throughout the specified useful-life period.
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(d) Crankcase emissions prohibited. Vehicles may not discharge crankcase emissions 

into the ambient atmosphere.

(e) On-board diagnostics. All vehicles must have an on-board diagnostic system as 

described in §86.1806.

(f) Altitude requirements. Emission standards apply at low-altitude conditions and at 

high-altitude conditions, except as noted in this subpart. 

(g) The cold CO and cold NMHC standards in this subpart refer to test procedures set 

forth in subpart C of this part and 40 CFR 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) shall 

comply with all requirements established for each consumed fuel (or blend of fuels in the case of 

flexible fueled vehicles). In the case of flexible-fueled vehicles operating on ethanol and 

gasoline, this involves additional exhaust emission measurements using the fuel specified in 40 

CFR 1065.725. No additional evaporative emission testing is required.

95. Section 86.1811-04 is amended by removing and reserving paragraph (h) and revising 

paragraphs (j) and (n) to read as follows:

§ 86.1811-04 – Emission standards for light-duty vehicles, light-duty trucks and 

medium-duty passenger vehicles.]

* * * * *

(j) Highway NO X 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 test electric vehicles according to the procedures specified in SAE J1634 (incorporated by 

reference in § 86.1). Manufacturers must measure emissions from hybrid electric vehicles 

(including plug-in hybrid electric vehicles) according to the procedures specified in SAE J1711

(incorporated by reference in §86.1), except that these procedures do not apply for plug-in hybrid 

electric vehicles during charge-depleting operation,
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* * * * *

96. 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 LDT4s. 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)(9) 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 subpart B of this 

part, 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. SFTP emissions in particular are calculated as a composite of test results over 

these driving schedules based on the following calculation:

SFTP (g/mi) = 0.35∙FTP + 0.28∙US06 + 0.37∙SC03

(iii) For vehicles that qualify for the derived 5-cycle method for determining fuel 

economy label values and are therefore not required to operate over the SC03 driving 

schedule under 40 CFR 600.115, you may alternatively use FTP emission results to 

substitute for the SC03 value in the calculation under paragraph (b)(1)(ii) of this section 

for a given vehicle for any testing under this section.
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(iv) Use E15 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 1066.665.

(vi) Measure emissions from hybrid electric vehicles to demonstrate compliance 

with the Tier 3 standards according to the procedures specified in SAE J1711 

(incorporated by reference in § 86.1).

(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 C

O

Form

aldehyde

F

TP1FTP TP S062

S

FTP

FTP

0

.030 .050 .003 .010

4

.2 0.004

1 The fleet-average FTP emission standard for 

NMOG+NOx is 0.026 g/mile for LDV and LDT1 if a manufacturer 

certifies one or more test groups based on a useful life of 120,000 

miles and 10 years in a given model year.

2 The US06 emission standard for PM is 0.020 g/mile for 

vehicles above 6,000 pounds GVWR.
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(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 or use emission credits for 

averaging, banking, and trading as described in §86.1861 for demonstrating compliance with 

the FTP 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 FTP credits between or among any 

test groups subject to standards under this section. You may not exchange FTP and SFTP 

credits.

(i) You may specify any of the FELs from Table 2 of this section 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:
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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:
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(A) You may subtract 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 fleetaverage 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 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 or use emission credits 

for averaging, banking, and trading as described in §86.1860 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 
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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. 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. 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, if you certify these vehicles to the Tier 3 PM standards in the model year 2017, 

you may count those projected U.S. sales toward your calculation for meeting the phasein percentage for that year (numerator only). 

(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, 

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 actual 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)(6)(i) of this section.

(iii) You may alternatively ask us to approve calculation of the annual percentage 

for a given model year based on production volumes instead of sales volumes.

(iv) Vehicles meeting the Tier 3 PM standards must meet those standards over the 

useful life as specified in §86.1805-17. Note that Interim Tier 3 vehicles may have 

different useful life values for PM emission standards than for other emission standards.

(v) 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.

(vi) Measure PM emissions from all vehicles using the same test fuel used for 
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measuring NMOG+NOx emissions. 

(vii) You may certify Interim Tier 3 vehicles based on carryover data.

(viii) 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 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)(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. For model year 2017, do not include vehicles above 6,000 

pounds GVWR (in the numerator or denominator). 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:
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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

If a manufacturer certifies one or more LDV or LDT1 test 

groups based on a useful life of 120,000 miles and 10 years in a given 

model year, calculate the adjusted fleet-average standard 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 
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on a useful life of 120,000 miles and 10 years.

2 Vehicles above 6,000 pounds GVWR must meet the Tier 3 

standards starting with the 2018 model year.

(ii) SFTP phase-in. The fleet-average SFTP emission standard for NMOG+NOx 

phases in over several years as described in this paragraph (b)(7)(ii). You must identify

FELs as 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)(7)(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:
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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 the 2018 model year.
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(C) You may use the Option 1 provisions specified in the LEV III program to 

demonstrate compliance with EPA’s SFTP standards instead of the phased-in fleetaverage SFTP standards specified in this paragraph (b)(7)(ii).

(iii) Interim provisions. (A) For LDT2 and HLDT certified to Bin 125 or Bin 160 

standards under this section through model year 2019, the Tier 2 useful life period 

applies as specified in §86.1805-12.

(B) You may alternatively use the E0 test fuel specified in §86.113 through 

model year 2019 for vehicles certified to bins higher than Bin 70 . You may not 

certify these vehicles in model year 2020 using carryover data.

(iv) 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 FTP and SFTP emission standards as specified in paragraphs 

(b)(1) through (6) of this section with 40, 70, and 100 percent of your projected nationwide 

sales of all vehicles 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)(8) are subject to the 

useful life provisions in §86.1805-12. Each vehicle counting toward the phase-in percentage 

under this paragraph (b)(8) must meet all the standards that apply based on the useful life 

provisions of §86.1805-17, and must use the Tier 3 test fuel specified in §86.113-07. 

Vehicles certified under this paragraph (b)(8) may not generate or use emission credits. 

(9) 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)(9). 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. Separate from any Tier 2 

demonstrations, calculate early Tier 3 emission credits as described in §86.1861 by

determining a fleet-average value for FTP emissions of NMOG+NOx based on the applicable 

bin standards and subtracting this value 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. Vehicles 

certified to the Tier 2 standards must meet all the Tier 2 requirements in §86.1811-10. You 
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must also continue to meet the fleet-average Tier 2 standards as long as they apply. You may

use these early credits as described in §86.1861 for demonstrating compliance with the FTP 

emission standard for NMOG+NOx; however, starting in model year 2018, use of early

credits is 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 sales to California sales to calculate an 

effective nationwide quantity. Sum these results for model years 2015 through 2017.

(ii) You may not use more early credits generated under this paragraph (b)(9) to 

meet Tier 3 emission standards than the calculated value of the effective nationwide 

credit quantity summed in paragraph (b)(9)(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)(9) 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 demonstrating compliance with the Tier 3 standards, subject to 

the five-year credit life described in §86.1861. 

(10) The following alternate standards apply for in-use testing with 2021 and earlier 

model year vehicles:

(i) The alternate in-use PM emission standard for FTP testing is 0.006 g/mile. 

(ii) The alternate in-use PM emission standards for SFTP testing are 0.015 g/mile 

for vehicles at or below 6,000 pounds GVWR and 0.025 g/mile for vehicles above 6,000 

pounds GVWR.

(iii) Alternate in-use NMOG+NOx emission standards for FTP testing apply for 

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 lowaltitude conditions.

(11) 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.
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(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 NMOG+NOx bin standard for FTP testing. Demonstrate compliance with this 

standard for low-mileage vehicles by applying the appropriate deterioration factor.

(d) Special provisions for Otto-cycle engines. The following special provisions apply for 

vehicles with Otto-cycle engines:

(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 
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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.

(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 mustdescribe 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:
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(i) For LDVs and LDT1s, the standard is 10.0 g/mile CO.

(ii) For LDT2s, LDT3s and LDT4s, 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 in-use except as otherwise specified in §86.1811-10(u) for in-use standards for 

applicable phase-in models. Testing with other fuels such as E85, 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:

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)

LDVs & LLDTs (<6,000 lbs 

GVWR) 0.3

HLDTs >6,000 lbs GVWR 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 lowaltitude 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 
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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 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 2022. If meeting the Tier 3 standards in model year 2022 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. 

97. A new §86.1813-17 is added to subpart S to read as follows:

§ 86.1813-17 Evaporative and refueling emission standards.

Vehicles must meet evaporative and refueling emission standards as specified in this 

section. 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 LDT4s.

(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.

(iii) Use E15 test fuel as required in §86.113, except as specified in this section.

(iv) Emissions are measured as total hydrocarbon; however, in the case of E15 

test fuel, multiply measured values by 1.1 to convert values to total hydrocarbon 

equivalent. 

(2) Diurnal and hot soak emissions may not exceed the Tier 3 emission standards, as 
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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 

test group. The FEL serves as the emission standard for the test group 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 or use emission credits for averaging, banking, or trading for vehicles required 

to meet the Tier 3 standards, other than electric vehicles and gaseous-fueled vehicles, as 

described in §86.1861 for demonstrating compliance with the hot soak plus diurnal 

emission standard starting in the 2017 model year. You comply with the emission 

standard for a given model year if you have enough credits to show that your fleetaverage emission level is at or below the applicable standard. You may exchange credits 

between or among test groups 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 fleetaverage Tier 3 standards:
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Table 1 of §86.1813-17—

Tier 3 Diurnal Plus Hot Soak Emission Standards (grams per test)

Vehicle category

Lowaltitude 

conditions

Highaltitude 

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:
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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 lightduty 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 LDVs and LDTs and 

0.030 g for HDVs when tested using the Bleed Emission Test Procedure adopted by the 

California Air Resources Board (incorporated by reference in §86.1). 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 non-integrated refueling emission control systems, the bleed emission test and 

standard do not apply to the refueling canister.

(3) Running losses may not exceed 0.05 g per mile when measured using the test 

procedures specified in § 86.134. 

(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 
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specified in 40 CFR 1066.840. 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 test groups 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 LDVs and LDT1s 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.
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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.

(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. 
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(b) Refueling emissions. 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 gasoline-fueled, diesel-fueled and 

methanol-fueled vehicles.

(2) 0.15 g THC per gallon of fuel dispensed for liquefied petroleum 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(f) 

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 fuel vehicles. The following provisions apply

specifically for gaseous fuel vehicles:

(1) Refueling receptacles on natural gas-fueled vehicles must comply with the 

receptacle provisions of the ANSI/AGA NGV1–1994 standard (incorporated by reference in 

§86.1). 

(2) 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 at or 

below 14,000 pounds GVWR that you certify early to the Tier 3 standards in paragraph (a) of 

this section, as long as the vehicle is not sold in California or any of the section 177 states. 

This applies in model years 2015 and 2016 for vehicles at or below 6,000 pounds GVWR 

and in model years 2015 through 2017 for vehicles above 6,000 pounds GVWR. For each 
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allowance you earn, you may count it as one compliant vehicle in a later model year during 

the phase-in period. As an example, selling 100,000 Tier 3 vehicles in 2016 and a total of 

400,000 vehicles at or below 14,000 pounds GVWR in 2017 would allow a manufacturer to 

“spend” up to 40,000 allowances in both 2017 and 2018, leaving a total of 20,000 allowances 

for 2019 through 2022. 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 for model year 2018 under the phase-in schedule described in 

paragraph (g)(5) of this section; however, you may not use those allowances to increase the 

value of APP in 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 generate emission credits. Allowances may not be traded to another 

company. You may earn additional allowances under this paragraph (g)(1) as follows:

(i) 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.

(ii) For vehicles above 10,000 pounds GVWR that you certify to the refueling 

emission standards in paragraph (b) of this section in model years 2015 through 2017, a 

single vehicle may produce two allowances if it is certified to the Tier 3 diurnal plus hot 

soak standard and the refueling standard. Allowances earned under this paragraph 

(g)(1)(ii) may alternatively be used in model years 2018 through 2022 to phase in the 

refueling standard.

(2) [Reserved]

(3) 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 higheremitting 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; 

however, they may generate or use emission credits only if they are certified to meet the 

emission standards of paragraph (a)(2) of this section. Vehicles that comply under this 

paragraph (g)(3) may not generate allowances under paragraph (g)(1) of this section, 

regardless of the calculated percentage of compliant vehicles in model year 2017.

(4) If you certify model year 2019 or earlier vehicles to the LEV III 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 leak 
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Page 646 of 995

standard specified in paragraph (a)(4) of this section and the high-altitude standards in 

paragraph (a)(2) of this section. You may not certify vehicles under this paragraph (g)(4) 

after model year 2019. 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).

(5) You may disregard the phase-in percentages specified in paragraph (a)(5) of this 

section for 2018 through 2022 if you instead comply with the alternate phase-in schedule 

described in this paragraph (g)(5). To do this, you must notify us of your intent before 

January 1, 2018, and include a detailed plan for complying with the alternate phase-in 

schedule. You comply with the alternate phase-in schedule by calculating an evaporative 

phase-in index at or above 1,040 using the following equation for model years 2018 through 

2022:

Evaporative phase-in index = 5∙APP2018 + 4∙APP2019 + 3∙APP2020 + 2∙APP2021 + 

APP2022

Where:

APP = The actual phase-in percentage of vehicles meeting the Tier 3 evaporative 

emission standards for the indicated model year, based on actual sales; you may instead ask 

us to calculate the annual percentage based on actual production volumes.

(6) You may alternatively use the E0 test fuel specified in §86.113 through model 

year 2019 for vehicles certified to emission standards comparable to the standards in this 

section based on testing specified by the California Air Resources Board. You may not 

certify these vehicles in model year 2020 using carryover data.

(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 in model year 2022 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. 

98. A new §86.1816-18 is added to subpart S to read as follows:
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§ 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 at or below 

14,000 pounds GVWR. 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 

HDVs. See §86.1813 for evaporative and refueling emission standards. This section may apply

to vehicles before model year 2018 as specified in paragraph (b)(10) 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 E15 test fuel as required in §86.113, except as specified in this section.

(4) Measure emissions from hybrid electric vehicles to demonstrate compliance with 

the standards of this section according to the procedures specified in SAE J1711 

(incorporated by reference in § 86.1).

(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:
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(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

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.

(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 1066.665.

(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:
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Table 1 of §86.1816-18

Fully Phased-in Tier 3 HDV Exhaust Emission Standards (g/mile)

HDV 

Class

Fleetaverage

NMO

G+NOx

PM Formal

dehyde

FTP F

TP

H

D-SFTP

FTP

2b 0.178 0

.008

0.

0101 0.006

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 lowaltitude 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 averaging, banking, or trading as described in §86.1860 

for demonstrating compliance with the FTP 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 credits between or among any test groups subject to standards under this section. 
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You may specify any of the FELs from Table 2 or Table 3 of this section 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)

F

EL Name

NMOG+NOx CO

F

TP (FEL)

H

D-SFTP1 TP

HDSFTP

Bi

n 250

0.

250

0.8

00 .4

22.0

Bi

n 200

0.

200

0.8

00 .2

22.0

Bi

n 170

0.

170

0.4

50 .2

12.0

Bi

n 150

0.

150

0.4

50 .2

12.0

Bi

n 02

0.

000

0.0

00 .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.
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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)

FE

L Name

NMOG+NOx CO 

FT

P (FEL)

HD

-SFTP TP

H

D-SFTP

Bi

n 400

0.4

00

0.5

50 .3

6.0

Bi

n 270

0.2

70

0.5

50 .2

6.0

Bi

n 230

0.2

30

0.3

50 .2

4.0

Bi

n 200

0.2

00

0.3

50 .7

4.0

Bi

n 01

0.0

00

0.0

00 .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]
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(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 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 actual 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)(6)(i) of this section.

(iii) You may alternatively ask us to approve calculation of the annual percentage

for a given model year based on production volumes instead of sales volumes.

(iv) Vehicles meeting the Tier 3 PM standards must meet those standards over the 

useful life as specified in §86.1805-17. Note that Interim Tier 3 vehicles may have 

different useful life values for PM emission standards than for other emission standards.

(v) Measure PM emissions from all vehicles using the same test fuel used for 

measuring NMOG+NOx emissions.

(vi) You may certify Interim Tier 3 vehicles based on carryover data.
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(vii) 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; include these vehicles in the fleet-average calculation 

by treating the sum of the NMOG and NOx emission standards as the Family Emission 

Limit under §86.1860. You may alternatively use the E0 test fuel specified in §86.113 

for 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)

Mo

del

Ye

ar

Class 

2b

Class 

3

201

6

1

0.333 0.548

201

7

1

0.310 0.508

201

8

0.278 0.451

201

9

0.253 0.400

202

0

0.228 0.349

202

1

0.203 0.298

202

2

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)(10) of this section.
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Table 5 of §86.1816-18

Transitional Tier 3 FTP Bin Standards (g/mile)1

C

lass

FE

L Name

N

MOG

N

Ox

P

M

C

O

formal

dehyde

2

b

Bi

n 395

0

.195

0.

200

0

.012

6

.4 0.032

Bi

n 340

0

.140

0.

200

0

.012

6

.4 0.032

3 Bi

n 630

0

.230

0.

400

0

.012

7

.3 0.040

Bi

n 570

0

.170

0.

400

0

.012

7

.3 0.040

1 Vehicles certified to Transitional Tier 3 FTP bins are not subject to HD-SFTP standards.

(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 all 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. You may meet 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 emissions 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. 

You may use averaging, banking, and trading relative to the Tier 3 FTP emission standard for 
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Page 656 of 995

NMOG+NOx during the phase-in period, but only if all the vehicles certified under 

§86.1816-08 have FELs that are at or below the applicable NMHC and NOx standards. 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. To generate emission credits during the phase-in 

period, all pre-Tier 3 vehicles must 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. 

You may optionally meet the Tier 3 standards before model year 2019.
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Table 6 of §86.1816-18

Alternative Phase-in Schedule 

M

odel

Ye

ar

Class 2b Class 3

PM Oth

er than PM PM Other than PM

20

19

40 65

%

40 60

%

20

20

70 77

%

70 73

%

20

21

100 88

%

10

0

87

%

20

22

100 100

%

10

0

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 complete heavy-duty vehicles at or below 14,000 pounds GVWR 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)(10) must comply with the PM standards 
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specified in §86.1816-08 instead of the Tier 3 PM standards specified in this section.

(12) 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 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 lowmileage 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 in model year 2022 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. 

99. 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 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.

* * * * *

100. Section 86.1818-12 is amended by revising paragraph (a) to read as follows:
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§ 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 LDVs, LDTs and MDPVs, 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.

* * * * *

101. Section §86.1821-01 is amended by adding paragraph (f) to read as follows:

§ 86.1821-01 Evaporative/refueling family determination.

* * * * *

(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.
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102. Section §86.1823-08 is amended by revising paragraph (g) to read as follows:

§ 86.1823-08 Durability demonstration procedures for exhaust emissions.

* * * * *

(g) Emission component durability. The manufacturer shall use good engineering 

judgment to determine that all emission-related components are designed to operate properly for 

the full useful life of the vehicles in actual use.

* * * * *

103. Section §86.1824-08 is amended by revising paragraphs (a), (f)(1), and (h) to read as 

follows:

§ 86.1824-08 Durability demonstration procedures for evaporative emissions.

* * * * *

(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. It does not apply for spitback or leak 

standards.

* * * * *

(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 
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Page 661 of 995

design, duration and severity to stabilize the permeability of all non-metallic fuel and evaporative 

system components to the mileage accumulation fuel constituents.

* * * * *

(h) Emission component durability. The manufacturer shall use good engineering 

judgment to determine that all emission-related components are designed to operate properly for 

the full useful life of the vehicles in actual use.

* * * * *

104. Section §86.1825-08 is amended by revising paragraph (h) to read as follows:

§ 86.1825-08 Durability demonstration procedures for refueling emissions.

* * * * *

(h) Emission component durability. The manufacturer shall use good engineering 

judgment to determine that all emission-related components are designed to operate properly for 

the full useful life of the vehicles in actual use.

* * * * *

105. 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.
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(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. 

(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.

106. 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 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.
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107. 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.

* * * * *

(iv) 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. 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 
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be based on previous emission tests, development tests, or other appropriate information, and 

good engineering judgment.

* * * * *

108. A new §86.1829-17 is added to subpart S to read as follows:

§86.1829-17 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 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 highaltitude 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 
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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: 

(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 as follows:

(i) Except as noted in paragraph (d)(1)(ii) of this section, manufacturers must 

submit PM test data for at least 25 percent of its durability data groups that are subject to 

the Tier 3 PM standards in §86.1811-17. For example, if a manufacturer has a mix of 

light-duty vehicles and light-duty trucks divided over a total of nine durability data 

groups in a given model year, three of them would need PM data for certification in that 

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 all of a 

manufacturer’s 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)(i), subject to the selection of durability data 

groups. 

(ii) In every model year that manufacturers have only one or two durability data 

groups subject to the Tier 3 PM standards, they must submit PM test data for certifying 

all their durability data groups. If manufacturers have three durability data groups subject 

to the Tier 3 PM standards in a given model year, they must submit PM test data for at 

least two of those durability data groups.

(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.
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(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. Vehicles fueled by liquefied petroleum gas are similarly exempted 

from submitting test data for the evaporative and refueling emission standards, except that 

refueling tests are required for systems that allow venting during the refueling operation.

(3) 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.

(4) 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.

(5) 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 (d)(12). 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, 
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canister volume, canister working capacity, 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.

(6) 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.

(7) 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:

(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, 

(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.

109. Section §86.1837-01 is amended by revising paragraph (a) to read as follows:

§ 86.1837-01 Rounding of emission measurements.
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(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. 

* * * * *

110. Section §86.1838-01 is revised to read as follows:

§ 86.1838-01 Small-volume manufacturer certification procedures.

(a) 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 small-volume 

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 §§ 86.1811-17, 86.1813-

17, and 86.1816-18. 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 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.

(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 
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(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 manufacturers 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 
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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 smallvolume status under paragraph (c) of this section.

(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 manufacturers and small-volume test groups shall demonstrate 

compliance with all applicable sections of this subpart, except as provided in paragraphs (c)(1) 

and (2) of this section. Small-volume manufacturers and small-volume test groups may

optionally meet the following requirements:

(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. Requirements for testing in-use vehicles apply as 

described in §86.1845, subject to the following additional provisions for small-volume 

manufacturers and small-volume test groups:

(i) Small-volume in-use verification test vehicles may be procured from 

customers or may be owned by, or under the control of the manufacturer, provided that 
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the vehicle has accumulated mileage in typical operation on public streets and has 

received typical maintenance.

(ii) In lieu of procuring small-volume 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 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 paragraphs (c)(2)(i) or (ii) of 

this section shall submit to the Agency, prior to the certification of the subject vehicles, a 

plan detailing how these provisions will be met.

111. 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.

* * * * *

112. Section 86.1844-01 is amended by revising paragraphs (a), (d)(7), (d)(8), (d)(9), (d)(11), 
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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 §86.1829–01. 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 1066.430 for 

each drive cycle or test phase, as appropriate.

(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.

(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 
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accessing the fuel system for measurements, and a method for pressurizing the fuel system to 

perform the procedure specified in 40 CFR 1066.840 without involving the fuel cap or filler 

neck.

* * * * *

(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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113. Section 86.1845-04 is amended by revising paragraphs (a)(3), (b)(3) introductory text, 

(b)(4), (b)(5), (b)(6), (b)(7), and (c) to read as follows:

iii.§ 86.1845-04 Manufacturer in-use verification testing requirements.

(a) * * *

(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 HDVs. 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 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 
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§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 Federal 

Test Procedure and the US06 portion of the Supplemental Federal Test Procedure 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 highway fuel economy test 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. 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.
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(C) If the most recent OBD leak check from paragraph (b)(5)(iii)(A) or (B) of 

this section shows a fault code, the vehicle is presumed to have failed the leak test. 

Manufacturers may perform the leak measurement procedure described in 40 CFR 

1066.840 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 over-ride a failure under paragraph (b)(5)(iii)(C) of this section.

(iv) For non-gaseous 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-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. 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 
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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 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 Federal Test 

Procedure and the US06 portion of the Supplemental Federal Test Procedure 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 

highway fuel economy test as described in part 600, subpart B of this chapter. One test 

vehicle from each test group shall receive a Federal Test Procedure 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. 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 non-gaseous 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-diurnalplus-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 
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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.

(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.

* * * * *

114. Section 86.1846-01 is revised to read as follows:

iv. § 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 and heavy-duty engines starting 

with model year 2007. These provisions do not apply to emissions of CO2, CH4, and N2O.

(2) [Reserved]

(3) [Reserved]

(4) 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) This requirement does not apply to Supplemental FTP testing or 

evaporative/refueling testing. Testing conducted at high altitude under the requirements 

of §86.1845 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 
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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 the leak 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 emission 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.

(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 Federal Test Procedure and/or the Supplemental Federal Test 

Procedure (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.
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(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 §86.1845rounded to 

the next highest whole number where appropriate. For each manufacturer with only one test 

group under §86.1845, such manufacturer shall have a maximum potential testing requirement 

under this section of one test group (or Agency-designated 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.

115. 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.

* * * * *
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(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.

* * * * *

116. 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 0.001 

g/mile for NMOG+NOx emissions and the nearest 0.001 g/test for evaporative emissions:
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i i

i 1

total

( )

b

N FEL

Fleet average value

N









Where:

i = A counter associated with each separate Tier 3 test group.

b = The number of separate Tier 3 test groups to which you certify your vehicles.

Ni = The actual sales for the model year for test group i.

FELi = The FEL selected for test group 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, 

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.

(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.
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(3) If you do not have enough emission credits to demonstrate compliance with a 

fleet-average standard in a given model year, you may carry forward a credit deficit for up to 

three model years. 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.

(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) The deadline for offsetting debits as specified in paragraph (e)(3) of this section 

serves as the starting date for calculating the statute of limitations with respect to violating the 

requirements of paragraph (e)(3) of this section, failing to satisfy the conditions upon which a 

certificate was issued, and selling, offering for sale, introducing or delivering into U.S. 

commerce, or importing vehicles not covered by a certificate.

117. 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 fleetaverage 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 LDT4s.

(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 fleet-average level 

is below the standard. Calculate negative emission credits if your fleet-average 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:
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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.

Volume = Sales volume in a given model year from the collection of test groups 

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) HDVs represent a separate averaging set with respect to all emission standards.

(ii) LDVs and LDTs together represent a single averaging set with respect to 

NMOG+NOx emission standards. Note that FTP and SFTP credits are not 

interchangeable.

(iii) 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 in 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) Credits expire after five years. For example, credits you generate in model year 

2018 may be used only through model year 2023.

(c) The credit-deficit provisions 40 CFR 1037.745 apply without modification to the 

NMOG+NOx and evaporative emission standards for Tier 3 vehicles.
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(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.

118. 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.

(a) Overview. This section describes reporting and recordkeeping requirements for 

vehicles subject to the following fleet-average or fleet-average standards:

(1) Tier 2 NOx emission standard for light-duty vehicles and light-duty trucks in 

§86.1811-04.

(2) Tier 3 FTP emission standard for NMOG+NOx for light-duty vehicles and lightduty trucks in §86.1811-17. 

(3) Tier 3 SFTP emission standard for NMOG+NOx for light-duty vehicles and lightduty trucks in §86.1811-17. 

(4) Tier 3 evaporative emission standards in §86.1813-17. 

(5) Tier 3 FTP emission standard for NMOG+NOx for heavy-duty vehicles in 

§86.1816-18.

(6) Cold-temperature NMHC standards in §86.1811-10.

(b) Maintenance of records. (1) The manufacturer producing any vehicles subject to a fleetaverage 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.
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(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.

(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 fleetaverage 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 with all phasein 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 
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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 lightduty trucks and with 40 CFR part 1068, subpart G, for heavy-duty vehicles. 
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119. 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.

* * * * *

120. Section 86.1864-10 is amended by revising paragraph (p) to read as follows:

§ 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.

121. 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 1066.840 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 
*** E.O. 12866 Review – Revised 3/25/13 – Do Not Cite, Quote, or Release During Review ***

Page 689 of 995

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 1066.840 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.

* * * * *

(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 1066.840 , according to the requirements of this 

paragraph (g).

* * * * *

122. Appendix I to Part 86 is amended by revising the appendix heading, paragraph (a)

before the table, and paragraphs (b), (c), and (d) introductory text 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, lightduty trucks, and heavy-duty vehicles certified under subpart S of this part.
*** E.O. 12866 Review – Revised 3/25/13 – Do Not Cite, Quote, or Release During Review ***

Page 690 of 995

(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

ime 

(sec.)

peed 

(kph)

64 .4

65 .8

66 0.3

67 3.7

68 7.1

69 0.5

70 3.0

71 5.2

72 6.7

73 7.4

74 6.6

75 6.0

76 5.6

77 5.9

78 6.1

79 6.3

80 6.7

81 8.2

82 7.5

83 4.9

84 3.5

85 0.1

86 8.3

87 7.8

88 8.8

89 9.3

90 0.7

91 3.0

92 5.4

93 8.3

94 1.6

95 4.7

96 7.5

97 8.6

98 0.7

99 2.0

00 3.6

01 5.1

02 6.7
*** E.O. 12866 Review – Revised 3/25/13 – Do Not Cite, Quote, or Release During Review ***

Page 691 of 995

03 7.7

04 8.5

05 9.2

06 9.2

07 9.0

08 8.9

09 8.7

10 8.7

11 8.7

12 8.7

13 8.7

14 8.9

15 9.1

16 9.6

17 0.2

18 0.9

19 1.3

20 1.8

21 2.4

22 2.8

23 3.4

24 4.1

25 5.1

26 6.0

27 6.6

28 6.9

29 7.0

30 6.9

31 6.6

32 6.6

33 6.8

34 7.1

35 7.5

36 7.7

37 8.1

38 8.3

39 8.6

40 8.7

41 8.7

42 8.5

43 8.5

44 8.5

45 8.5

46 8.5

47 8.5

48 8.4

49 8.1

50 7.8

51 7.1

52 6.6

53 6.2

54 5.9

55 5.6

56 5.5

57 5.8

58 5.9

59 6.0

60 6.0

61 5.7

62 5.3

63 4.9

64 4.5

65 4.0

66 4.3

67 3.9
*** E.O. 12866 Review – Revised 3/25/13 – Do Not Cite, Quote, or Release During Review ***

Page 692 of 995

68 3.8

69 3.6

70 3.4

71 3.5

72 3.7

73 4.0

74 4.4

75 4.9

76 5.4

77 5.9

78 6.9

79 7.4

80 7.6

81 8.0

82 8.0

83 7.8

84 7.2

85 6.5

86 5.5

87 4.4

88 3.4

89 3.4

90 3.4

91 2.9

92 1.9

93 1.8

94 1.9

95 1.8

96 1.4

97 1.3

98 1.3

99 1.3

00 0.9

01 0.3

02 9.8

03 8.9

04 7.8

05 6.6

06 5.4

07 4.1

08 3.0

09 1.8

10 9.9

11 8.3

12 6.5

13 5.0

14 3.7

15 2.6

16 1.7

17 1.6

18 1.1

19 0.0

20 8.5

21 5.7

22 2.3

23 0.8

24 9.8

25 9.2

26 7.6

27 6.1

28 2.9

29 1.2

30 .3

31 .9

32 .5
*** E.O. 12866 Review – Revised 3/25/13 – Do Not Cite, Quote, or Release During Review ***

Page 693 of 995

(c) EPA driving schedule for class 3 heavy-duty vehicles. This driving schedule is also 

known as the LA-92 cycle.

ime 

(sec.)

peed 

(mph)

.0

.0

.0

.0

.0

.0

.0

.0

.0

0 .0

1 .0

2 .0

3 .0

4 .0

5 .0

6 .0

7 .0

8 .0

9 .0

0 .0

1 .2

2 .2

3 .3

4 .8

5 0.8

6 2.3

7 3.1

8 2.3

9 2.3

0 1.5

1 1.5

2 1.1

3 1.1

4 1.1

5 3.1

6 5.0

7 6.9

8 6.9

9 6.1

0 5.7

1 5.4

2 5.0

3 3.8

4 0.8

5 .4

6 .1

7 .2

8 .5

9 .5

0 .5

1 .0

2 .0

3 .0

4 .0

5 .0

6 .0

7 .0

8 .0

9 .0

0 .0

1 .0
*** E.O. 12866 Review – Revised 3/25/13 – Do Not Cite, Quote, or Release During Review ***

Page 694 of 995

2 .0

3 .2

4 .5

5 .7

6 1.1

7 3.8

8 6.5

9 8.4

0 0.4

1 0.7

2 9.6

3 7.3

4 2.3

5 .1

6 .1

7 .6

8 2.7

9 5.7

0 8.0

1 0.4

2 1.9

3 3.4

4 3.8

5 4.6

6 5.0

7 6.1

8 6.1

9 6.9

0 6.9

1 6.9

2 6.5

3 5.7

4 1.9

5 6.5

6 0.0

7 .6

8 .5

9 .4

00 .0

01 .0

02 .0

03 .0

04 .0

05 .0

06 .0

07 .0

08 .4

09 .2

10 .9

11 .8

12 .7

13 1.5

14 4.6

15 8.0

16 1.5

17 5.0

18 8.4

19 0.7

20 1.9

21 2.3

22 2.3

23 1.9

24 0.3

25 8.0

26 4.2
*** E.O. 12866 Review – Revised 3/25/13 – Do Not Cite, Quote, or Release During Review ***

Page 695 of 995

27 0.0

28 6.1

29 1.5

30 .1

31 .0

32 .5

33 .9

34 .0

35 .0

36 .0

37 .0

38 .0

39 .0

40 .0

41 .0

42 .0

43 .5

44 .9

45 2.7

46 6.5

47 0.0

48 3.0

49 5.7

50 8.0

51 0.7

52 2.6

53 4.2

54 5.3

55 6.9

56 6.9

57 7.2

58 7.6

59 7.6

60 7.6

61 7.2

62 7.2

63 6.9

64 6.5

65 6.5

66 4.9

67 3.4

68 1.9

69 9.2

70 5.0

71 5.0

72 6.1

73 7.6

74 9.2

75 1.1

76 2.3

77 4.2

78 4.9

79 5.7

80 6.5

81 6.9

82 6.9

83 7.2

84 7.6

85 7.2

86 7.6

87 8.0

88 8.4

89 9.2

90 9.6

91 9.9
*** E.O. 12866 Review – Revised 3/25/13 – Do Not Cite, Quote, or Release During Review ***

Page 696 of 995

92 0.7

93 0.3

94 1.1

95 1.1

96 0.7

97 1.9

98 3.9

99 5.9

00 .9

01 .7

02 .4

03 .4

04 .7

05 .8

06 .8

07 .5

08 .0

09 .0

10 .0

11 .0

12 .0

13 .0

14 .0

15 .0

16 .0

17 .0

18 .0

19 .0

20 .0

21 .0

22 .0

23 .0

24 .0

25 .0

26 .0

27 .0

28 .0

29 .0

30 .0

31 .0

32 .0

33 .0

34 .0

35 .0

36 .0

37 .0

38 .5

39 .0

40 .8

41 1.5

42 4.2

43 5.4

44 6.1

45 6.1

46 6.9

47 6.5

48 6.9

49 8.0

50 9.2

51 0.4

52 0.4

53 1.1

54 1.1

55 2.3

56 3.0
*** E.O. 12866 Review – Revised 3/25/13 – Do Not Cite, Quote, or Release During Review ***

Page 697 of 995

57 3.8

58 4.2

59 4.6

60 5.0

61 5.7

62 5.7

63 6.5

64 7.6

65 8.4

66 9.2

67 0.3

68 1.1

69 1.1

70 0.7

71 1.1

72 9.6

73 9.2

74 9.2

75 8.8

76 8.0

77 3.0

78 1.1

79 1.5

80 0.7

81 0.7

82 9.6

83 6.5

84 3.1

85 .6

86 .3

87 .8

88 .8

89 .0

90 .0

91 .0

92 .0

93 .0

94 .0

95 .0

96 .0

97 .0

98 .0

99 .0

00 .0

01 .0

02 .0

03 .0

04 .0

05 .0

06 .0

07 .0

08 .0

09 .0

10 .0

11 .0

12 .0

13 .4

14 .7

15 .3

16 1.5

17 5.4

18 8.4

19 0.7

20 4.2

21 6.9
*** E.O. 12866 Review – Revised 3/25/13 – Do Not Cite, Quote, or Release During Review ***

Page 698 of 995

22 9.6

23 1.1

24 2.6

25 3.8

26 4.9

27 6.9

28 9.2

29 1.1

30 3.0

31 3.8

32 4.5

33 5.3

34 5.3

35 4.9

36 4.5

37 3.8

38 3.4

39 2.6

40 1.9

41 1.5

42 0.7

43 0.3

44 1.1

45 1.5

46 2.6

47 3.4

48 4.2

49 4.9

50 5.7

51 6.5

52 6.8

53 7.2

54 8.0

55 7.6

56 8.4

57 8.0

58 7.2

59 6.1

60 5.7

61 4.9

62 4.2

63 3.8

64 4.5

65 4.9

66 5.3

67 6.5

68 8.0

69 8.8

70 9.5

71 9.9

72 9.9

73 9.9

74 9.5

75 9.5

76 8.8

77 8.8

78 8.8

79 8.4

80 8.8

81 9.5

82 0.3

83 0.7

84 1.8

85 2.6

86 3.4
*** E.O. 12866 Review – Revised 3/25/13 – Do Not Cite, Quote, or Release During Review ***

Page 699 of 995

87 4.1

88 5.3

89 5.3

90 6.1

91 6.4

92 6.4

93 6.4

94 7.2

95 6.8

96 7.6

97 7.6

98 7.6

99 8.0

00 8.0

01 8.4

02 8.4

03 8.8

04 9.1

05 8.8

06 8.8

07 8.0

08 8.0

09 7.6

10 7.6

11 7.6

12 7.6

13 7.6

14 9.1

15 9.5

16 9.9

17 0.3

18 0.3

19 1.1

20 0.3

21 9.9

22 9.5

23 9.1

24 9.1

25 9.5

26 9.5

27 9.5

28 9.9

29 0.3

30 0.7

31 0.7

32 1.4

33 1.8

34 1.8

35 1.8

36 1.8

37 1.1

38 0.7

39 0.3

40 0.3

41 0.3

42 9.5

43 8.8

44 9.1

45 8.8

46 8.8

47 8.8

48 8.4

49 8.0

50 8.0

51 8.0
*** E.O. 12866 Review – Revised 3/25/13 – Do Not Cite, Quote, or Release During Review ***

Page 700 of 995

52 8.4

53 9.1

54 9.5

55 9.9

56 9.9

57 0.3

58 1.1

59 1.1

60 1.1

61 1.4

62 1.4

63 1.1

64 0.7

65 9.9

66 9.1

67 9.1

68 9.1

69 9.9

70 9.5

71 9.9

72 8.8

73 8.0

74 7.6

75 6.8

76 6.1

77 5.3

78 4.1

79 2.6

80 9.2

81 6.1

82 3.0

83 7.2

84 9.6

85 1.5

86 6.5

87 5.7

88 8.4

89 1.5

90 5.0

91 7.3

92 9.2

93 0.7

94 1.5

95 1.1

96 1.1

97 0.3

98 0.0

99 0.0

00 9.6

01 0.0

02 8.8

03 8.8

04 8.0

05 8.4

06 8.0

07 8.4

08 8.4

09 8.8

10 8.4

11 8.4

12 8.0

13 6.5

14 4.2

15 2.7

16 0.4
*** E.O. 12866 Review – Revised 3/25/13 – Do Not Cite, Quote, or Release During Review ***

Page 701 of 995

17 7.7

18 5.7

19 3.1

20 0.8

21 .4

22 .3

23 .0

24 .8

25 .5

26 .9

27 .8

28 .0

29 .0

30 .0

31 .8

32 .9

33 .8

34 .9

35 .6

36 1.1

37 1.1

38 0.4

39 .8

40 .2

41 0.0

42 0.4

43 0.4

44 .4

45 .9

46 .0

47 .0

48 .0

49 .0

50 .0

51 .0

52 .0

53 .0

54 .0

55 .0

56 .0

57 .0

58 .0

59 .0

60 .0

61 .0

62 .0

63 .0

64 .0

65 .0

66 .0

67 .0

68 .0

69 .0

70 .0

71 .0

72 .4

73 .5

74 .5

75 .1

76 0.4

77 4.2

78 6.9

79 9.2

80 0.0

81 1.5
*** E.O. 12866 Review – Revised 3/25/13 – Do Not Cite, Quote, or Release During Review ***

Page 702 of 995

82 3.4

83 4.6

84 4.2

85 0.0

86 6.9

87 3.4

88 3.4

89 5.7

90 8.4

91 1.1

92 3.4

93 5.3

94 7.6

95 8.8

96 0.3

97 0.7

98 1.5

99 1.1

00 1.1

01 0.3

02 0.3

03 0.3

04 0.7

05 1.1

06 2.3

07 2.6

08 2.6

09 2.6

10 1.1

11 6.9

12 2.3

13 8.0

14 3.8

15 .6

16 .6

17 .1

18 0.0

19 4.2

20 7.3

21 0.0

22 1.5

23 2.3

24 2.3

25 2.3

26 2.3

27 3.0

28 3.0

29 2.7

30 2.3

31 1.9

32 2.7

33 3.8

34 5.0

35 5.3

36 5.7

37 6.5

38 6.9

39 7.3

40 8.0

41 9.2

42 0.0

43 0.0

44 9.6

45 9.6

46 8.8
*** E.O. 12866 Review – Revised 3/25/13 – Do Not Cite, Quote, or Release During Review ***

Page 703 of 995

47 8.4

48 8.0

49 7.3

50 5.7

51 4.6

52 5.0

53 6.5

54 8.0

55 9.6

56 0.7

57 2.3

58 3.0

59 4.2

60 4.6

61 5.3

62 6.1

63 6.1

64 6.9

65 6.9

66 7.6

67 7.6

68 8.4

69 8.0

70 7.6

71 7.6

72 7.2

73 6.9

74 6.1

75 5.7

76 6.1

77 5.7

78 5.7

79 5.7

80 6.1

81 6.1

82 5.7

83 5.7

84 4.9

85 4.6

86 4.2

87 3.8

88 3.4

89 3.0

90 0.3

91 9.2

92 8.4

93 5.0

94 1.1

95 6.9

96 3.4

97 3.1

98 2.3

99 2.7

00 5.7

01 9.2

02 2.3

03 4.6

04 5.7

05 6.5

06 6.5

07 6.9

08 7.3

09 7.3

10 7.6

11 8.4
*** E.O. 12866 Review – Revised 3/25/13 – Do Not Cite, Quote, or Release During Review ***

Page 704 of 995

12 8.8

13 8.8

14 9.2

15 8.8

16 8.8

17 8.0

18 8.0

19 7.6

20 6.5

21 4.6

22 0.7

23 6.5

24 5.0

25 4.2

26 4.2

27 3.8

28 3.8

29 1.9

30 .4

31 .2

32 .2

33 .0

34 .0

35 .0

36 .0

37 .0

38 .0

39 .0

40 .0

41 .0

42 .0

43 .0

44 .0

45 .0

46 .0

47 .0

48 .0

49 .0

50 .0

51 .0

52 .0

53 .0

54 .0

55 .0

56 .0

57 .0

58 .0

59 .0

60 .0

61 .0

62 .0

63 .5

64 .4

65 .2

66 1.5

67 4.6

68 7.3

69 9.2

70 1.1

71 0.7

72 0.7

73 9.6

74 8.4

75 6.9

76 6.9
*** E.O. 12866 Review – Revised 3/25/13 – Do Not Cite, Quote, or Release During Review ***

Page 705 of 995

77 6.5

78 6.9

79 6.9

80 6.9

81 7.3

82 9.2

83 0.4

84 1.1

85 2.3

86 2.3

87 2.7

88 2.3

89 2.7

90 2.3

91 3.8

92 5.7

93 7.6

94 9.6

95 0.0

96 9.2

97 7.6

98 5.0

99 3.8

00 3.4

01 4.2

02 3.4

03 3.0

04 0.4

05 8.8

06 7.3

07 5.0

08 3.1

09 .2

10 .9

11 .6

12 .6

13 .6

14 .2

15 .4

16 .6

17 .5

18 .3

19 .3

20 .9

21 .1

22 .1

23 .6

24 .7

25 .3

26 .3

27 .1

28 .2

29 .5

30 .8

31 .2

32 .5

33 .5

34 .5

35 .6

36 .8

37 .5

38 .8

39 .5

40 .8

41 .3
*** E.O. 12866 Review – Revised 3/25/13 – Do Not Cite, Quote, or Release During Review ***

Page 706 of 995

42 .0

43 .2

44 .9

45 3.8

46 8.8

47 3.8

48 7.3

49 0.7

50 3.8

51 7.6

52 0.7

53 3.8

54 6.1

55 8.0

56 9.5

57 1.5

58 3.0

59 4.5

60 5.7

61 6.8

62 8.0

63 9.1

64 0.3

65 1.1

66 1.8

67 1.8

68 1.8

69 1.8

70 2.6

71 3.4

72 3.0

73 3.0

74 2.6

75 1.8

76 1.8

77 2.2

78 2.2

79 2.6

80 3.7

81 4.5

82 4.9

83 6.0

84 6.0

85 6.8

86 6.4

87 6.8

88 7.2

89 6.4

90 6.4

91 6.0

92 5.7

93 5.7

94 6.4

95 6.0

96 5.7

97 5.3

98 5.3

99 4.5

00 4.5

01 4.1

02 3.7

03 3.7

04 3.7

05 4.5

06 4.5
*** E.O. 12866 Review – Revised 3/25/13 – Do Not Cite, Quote, or Release During Review ***

Page 707 of 995

07 4.9

08 4.5

09 4.1

10 4.9

11 5.3

12 5.3

13 5.3

14 4.1

15 3.4

16 3.0

17 3.4

18 4.1

19 4.9

20 5.3

21 4.5

22 4.1

23 3.4

24 3.7

25 3.4

26 3.4

27 3.4

28 3.4

29 3.7

30 4.5

31 5.3

32 4.9

33 3.7

34 3.0

35 9.9

36 5.3

37 0.7

38 9.2

39 8.0

40 6.1

41 4.2

42 1.1

43 9.9

44 6.1

45 2.6

46 9.2

47 4.6

48 0.7

49 9.2

50 6.5

51 5.0

52 1.9

53 .6

54 .4

55 .8

56 .2

57 .0

58 .0

59 .0

60 .2

61 .1

62 .0

63 .4

64 1.5

65 4.6

66 6.9

67 8.8

68 1.1

69 3.8

70 6.5

71 8.0
*** E.O. 12866 Review – Revised 3/25/13 – Do Not Cite, Quote, or Release During Review ***

Page 708 of 995

72 9.6

73 0.7

74 2.6

75 4.2

76 5.3

77 6.1

78 6.9

79 8.0

80 8.0

81 8.0

82 8.0

83 8.0

84 7.2

85 6.9

86 6.1

87 5.7

88 4.9

89 4.9

90 3.8

91 1.5

92 8.8

93 5.7

94 4.6

95 3.4

96 2.3

97 1.5

98 0.0

99 0.0

000 9.2

001 9.2

002 8.0

003 1.9

004 .9

005 .7

006 .8

007 .4

008 .0

009 .0

010 .0

011 .0

012 .0

013 .0

014 .0

015 .0

016 .0

017 .0

018 .0

019 .0

020 .0

021 .0

022 .0

023 .4

024 .7

025 .1

026 .2

027 1.5

028 4.2

029 6.1

030 8.0

031 0.0

032 1.5

033 3.0

034 4.2

035 5.0

036 5.7
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Page 709 of 995

037 6.9

038 7.6

039 7.6

040 8.4

041 9.2

042 9.2

043 0.0

044 9.6

045 9.6

046 8.8

047 8.0

048 3.8

049 8.8

050 1.9

051 .1

052 .5

053 .5

054 .2

055 .1

056 0.4

057 3.1

058 5.4

059 8.0

060 0.4

061 3.0

062 5.3

063 7.3

064 8.8

065 0.3

066 1.1

067 2.3

068 1.9

069 2.3

070 1.9

071 1.1

072 8.8

073 5.0

074 2.7

075 8.8

076 5.4

077 3.4

078 1.9

079 .8

080 .0

081 .9

082 .3

083 .7

084 .5

085 .5

086 0.8

087 3.8

088 6.1

089 8.4

090 0.4

091 1.9

092 1.9

093 0.7

094 7.3

095 3.1

096 .6

097 .8

098 0.8

099 2.7

100 4.2

101 4.6
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Page 710 of 995

102 3.1

103 1.1

104 1.1

105 1.1

106 3.1

107 5.7

108 8.4

109 0.7

110 3.8

111 5.7

112 8.0

113 0.0

114 1.1

115 2.3

116 4.2

117 5.7

118 6.9

119 8.8

120 0.3

121 1.5

122 2.2

123 3.0

124 3.8

125 3.8

126 3.4

127 3.0

128 2.2

129 1.9

130 1.5

131 1.9

132 1.9

133 1.9

134 2.2

135 2.6

136 2.6

137 2.6

138 2.6

139 2.6

140 2.6

141 2.6

142 2.2

143 3.0

144 3.4

145 3.0

146 2.6

147 1.9

148 0.7

149 6.9

150 2.6

151 8.0

152 3.4

153 8.4

154 4.6

155 2.3

156 .2

157 .8

158 .9

159 .4

160 .0

161 .0

162 .0

163 .0

164 .0

165 .4

166 .2
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Page 711 of 995

167 .2

168 1.9

169 4.2

170 5.7

171 5.0

172 4.2

173 3.4

174 3.8

175 4.6

176 4.6

177 4.2

178 6.1

179 5.7

180 5.7

181 4.6

182 3.1

183 0.0

184 .3

185 .5

186 .8

187 .0

188 .0

189 .0

190 .0

191 .4

192 .7

193 .3

194 1.5

195 5.4

196 9.2

197 1.9

198 3.8

199 5.0

200 6.1

201 7.3

202 8.8

203 0.0

204 9.6

205 9.6

206 8.8

207 6.1

208 2.3

209 9.2

210 6.5

211 2.7

212 .6

213 .9

214 .2

215 .3

216 .8

217 .0

218 .0

219 .0

220 .0

221 .0

222 .0

223 .0

224 .0

225 .0

226 .0

227 .0

228 .0

229 .0

230 .0

231 .0
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Page 712 of 995

232 .0

233 .0

234 .0

235 .0

236 .0

237 .0

238 .0

239 .0

240 .5

241 0.4

242 5.4

243 7.3

244 7.3

245 8.4

246 1.5

247 4.6

248 7.3

249 0.0

250 1.5

251 1.9

252 2.6

253 3.4

254 4.9

255 6.5

256 7.6

257 9.2

258 0.3

259 0.7

260 1.1

261 0.7

262 0.7

263 0.7

264 1.5

265 2.6

266 3.0

267 4.5

268 5.3

269 5.3

270 4.9

271 3.4

272 0.3

273 8.0

274 6.1

275 6.5

276 8.0

277 9.2

278 0.7

279 2.2

280 3.4

281 4.9

282 5.7

283 6.1

284 6.8

285 6.5

286 6.5

287 6.5

288 6.1

289 6.1

290 6.1

291 6.8

292 7.6

293 8.0

294 8.4

295 8.0

296 8.0
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Page 713 of 995

297 7.2

298 6.5

299 6.8

300 7.2

301 8.4

302 8.4

303 8.8

304 8.4

305 7.6

306 6.5

307 4.2

308 2.2

309 1.5

310 1.1

311 0.7

312 0.3

313 9.6

314 9.2

315 8.8

316 8.0

317 7.6

318 7.2

319 6.5

320 4.6

321 1.5

322 9.6

323 9.2

324 8.8

325 8.8

326 8.0

327 8.0

328 8.4

329 9.6

330 0.0

331 0.3

332 9.2

333 6.5

334 5.3

335 5.0

336 4.6

337 4.6

338 5.3

339 6.1

340 7.3

341 8.4

342 9.2

343 9.2

344 9.6

345 0.0

346 1.1

347 2.6

348 3.8

349 4.6

350 4.9

351 4.6

352 4.9

353 4.6

354 4.9

355 4.9

356 4.9

357 4.2

358 3.8

359 2.6

360 1.5

361 0.0
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Page 714 of 995

362 8.8

363 7.3

364 3.8

365 3.0

366 3.0

367 2.3

368 0.4

369 8.8

370 7.7

371 6.1

372 4.6

373 2.7

374 1.1

375 .2

376 .8

377 .3

378 .1

379 .0

380 .2

381 .5

382 .7

383 .3

384 .5

385 .2

386 .0

387 .2

388 .2

389 .3

390 .8

391 0.8

392 2.3

393 3.1

394 2.3

395 2.3

396 1.5

397 1.5

398 1.1

399 1.1

400 1.1

401 3.1

402 5.0

403 6.9

404 6.9

405 6.1

406 5.7

407 5.4

408 5.0

409 3.8

410 0.8

411 .4

412 .1

413 .2

414 .5

415 .5

416 .5

417 .0

418 .0

419 .0

420 .0

421 .0

422 .0

423 .0

424 .0

425 .0

426 .0
*** E.O. 12866 Review – Revised 3/25/13 – Do Not Cite, Quote, or Release During Review ***

Page 715 of 995

427 .0

428 .0

429 .0

430 .0

431 .0

432 .0

433 .0

434 .0

435 .0

436 .0

437 .0

438 .0

439 .0

440 .0

441 .0

442 .0

443 .0

444 .0

445 .0

446 .0

447 .0

448 .0

449 .0

450 .0

451 .0

452 .0

453 .0

454 .0

455 .0

456 .2

457 .2

458 .3

459 .8

460 0.8

461 2.3

462 3.1

463 2.3

464 2.3

465 1.5

466 1.5

467 1.1

468 1.1

469 1.1

470 3.1

471 5.0

472 6.9

473 6.9

474 6.1

475 5.7

476 5.4

477 5.0

478 3.8

479 0.8

480 .4

481 .1

482 .2

483 .5

484 .5

485 .5

486 .0

487 .0

488 .0

489 .0

490 .0

491 .0
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Page 716 of 995

492 .0

493 .0

494 .0

495 .0

496 .0

497 .0

498 .2

499 .5

500 .7

501 1.1

502 3.8

503 6.5

504 8.4

505 0.4

506 0.7

507 9.6

508 7.3

509 2.3

510 .1

511 .1

512 .6

513 2.7

514 5.7

515 8.0

516 0.4

517 1.9

518 3.4

519 3.8

520 4.6

521 5.0

522 6.1

523 6.1

524 6.9

525 6.9

526 6.9

527 6.5

528 5.7

529 1.9

530 6.5

531 0.0

532 .6

533 .5

534 .4

535 .0

536 .0

537 .0

538 .0

539 .0

540 .0

541 .0

542 .0

543 .4

544 .2

545 .9

546 .8

547 .7

548 1.5

549 4.6

550 8.0

551 1.5

552 5.0

553 8.4

554 0.7

555 1.9

556 2.3
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Page 717 of 995

557 2.3

558 1.9

559 0.3

560 8.0

561 4.2

562 0.0

563 6.1

564 1.5

565 .1

566 .0

567 .5

568 .9

569 .0

570 .0

571 .0

572 .0

573 .0

574 .0

575 .0

576 .0

577 .0

578 .5

579 .9

580 2.7

581 6.5

582 0.0

583 3.0

584 5.7

585 8.0

586 0.7

587 2.6

588 4.2

589 5.3

590 6.9

591 6.9

592 7.2

593 7.6

594 7.6

595 7.6

596 7.2

597 7.2

598 6.9

599 6.5

600 6.5

601 4.9

602 3.4

603 1.9

604 9.2

605 5.0

606 5.0

607 6.1

608 7.6

609 9.2

610 1.1

611 2.3

612 4.2

613 4.9

614 5.7

615 6.5

616 6.9

617 6.9

618 7.2

619 7.6

620 7.2

621 7.6
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Page 718 of 995

622 8.0

623 8.4

624 9.2

625 9.6

626 9.9

627 0.7

628 0.3

629 1.1

630 1.1

631 0.7

632 1.9

633 3.9

634 5.9

635 .9

636 .7

637 .4

638 .4

639 .7

640 .8

641 .8

642 .5

643 .0

644 .0

645 .0

646 .0

647 .0

648 .0

649 .0

650 .0

651 .0

652 .0

653 .0

654 .0

655 .0

656 .0

657 .0

658 .0

659 .0

660 .0

661 .0

662 .0

663 .0

664 .0

665 .0

666 .0

667 .0

668 .0

669 .0

670 .0

671 .0

672 .0

673 .5

674 .0

675 .8

676 1.5

677 4.2

678 5.4

679 6.1

680 6.1

681 6.9

682 6.5

683 6.9

684 8.0

685 9.2

686 0.4
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Page 719 of 995

687 0.4

688 1.1

689 1.1

690 2.3

691 3.0

692 3.8

693 4.2

694 4.6

695 5.0

696 5.7

697 5.7

698 6.5

699 7.6

700 8.4

701 9.2

702 0.3

703 1.1

704 1.1

705 0.7

706 1.1

707 9.6

708 9.2

709 9.2

710 8.8

711 8.0

712 3.0

713 1.1

714 1.5

715 0.7

716 0.7

717 9.6

718 6.5

719 3.1

720 .6

721 .3

722 .8

723 .8

724 .0

725 .0

726 .0

727 .0

728 .0

729 .0

730 .0

731 .0

732 .0

733 .0

734 .0

735 .0
Page 720 of 995

(d) EPA driving schedule for testing heavy-duty vehicles above 14,000 pounds GVWR. 

This driving schedule applies for testing vehicles subject to evaporative emission standards under 

subpart A of this part.

* * * * *

Appendix XIII to Part 86—[Removed]

28. Appendix XIII to Part 86 is removed.

Appendix XIV to Part 86—[Removed]

28. Appendix XIV to Part 86 is removed.

Appendix XV to Part 86—[Removed]

28. Appendix XV to Part 86 is removed.

Appendix XVI to Part 86—[Removed]

28. Appendix XVI to Part 86 is removed.

Appendix XVII to Part 86—[Removed]

28. Appendix XVII to Part 86 is removed.

Appendix XVIII to Part 86—[Removed]

28. Appendix XVIII to Part 86 is removed.

PART 600—FUEL ECONOMY AND GREENHOUSE GAS EXHAUST 

EMISSIONS OF MOTOR VEHICLES
Page 721 of 995

14. The authority citation for part 600 continues to read as follows:

Authority: 49 U.S.C. 32901—23919q, Pub. L. 109–58.

Subpart A—General Provisions

16. The heading for subpart A is revised as set forth above. 

28. Section 600.011 is amended by revising paragraphs (b), (c)(2), and (c)(3) to read as 

follows: 

§ 600.011 Incorporation by reference.

* * * * *

(b) American Society for Testing and Materials, 100 Barr Harbor Drive, P.O. Box C700, 

West Conshohocken, PA, 19428-2959, (610) 832-9585, http://www.astm.org/.

(1) ASTM D975–11 Standard Specification for Diesel Fuel Oils, approved March 1, 

2011, IBR approved for § 600.107–08(b). 

(2) ASTM D 1298–99 (Reapproved 2005) Standard Practice for Density, Relative 

Density (Specific Gravity), or API Gravity of Crude Petroleum and Liquid Petroleum 

Products by Hydrometer Method, approved November 1, 2005, IBR approved for §§ 

600.113–12(f) and (g) and 600.510-12(g).

(3) ASTM D 1945–03 (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 D 3338/D 3338M –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 D 3343–05 (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, Revised October 2012, Battery Electric Vehicle Energy Consumption 

and Range Test Procedure, 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, June 2010, 
Page 722 of 995

IBR approved for §§ 600.114-12(c) and (f), 600.116-12(b) and (c), and 600.311-12(d), (j), 

and (k).

* * * * *

Subpart B—[Amended]

§§ 600.113-08 and 600.114-08 —[Removed]

123. Subpart B is amended by removing the following sections: §§ 600.113-08 and 600.114-

08.

28. 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, 

and (c)(2) introductory text.

§ 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 charge-sustaining 

operation from SAE J1711 (incorporated by reference in § 600.011). We may approve alternate 

measurement procedures with respect to these vehicles if that is necessary or appropriate for 

meeting the objectives of this part.
Page 723 of 995

(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 chargedepleting and charge-sustaining operation using the following utility factors except as specified 

in this paragraph (b):

* * * * *

(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 (b):

* * * * *

Subpart C—[Amended]

§§ 600.206-08, 600.207-08, 600.208 -08, 600.209-08, 600.210-08 —[Removed]

124. Subpart C is amended by removing the following sections: §§ 600.206-08, 600.207-08, 

600.208-08, 600.209-08, 600.210-08.

Subpart D—[Amended]

§§ 600.302-08, 600.311-08 —[Removed]

125. Subpart D is amended by removing the following sections: 600.302-08, 600.311-08.

126. 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 
Page 724 of 995

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.

Table 1 of §600.311–12—Criteria for Establishing 

Smog Rating for Model Year 2025 and Later

Ra

ting

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

8 — TZEV

10 Bin 0 ZEV

Table 2 of §600.311–12—Criteria for Establishing 

Smog Rating for Model Years 2018 -2024

Ra

ting

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

9 — — TZEV

10 Bin 0 Bin 1 ZEV
Page 725 of 995

Table 3 of §600.311–12—Criteria for Establishing 

Smog Rating through Model Year 2017

R

ating

U.S. EPA 

Tier 2 Emission 

Standard

California Air Resources 

Board LEV II 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

6 Bin 4 ULEV II

7 Bin 3 —

8 Bin 2 SULEV II

9 — PZEV

10 Bin 1 ZEV

* * * * *

Subpart F—[Amended]

§§ 600.507-08, 600.509-08, 600.510-08, 600.512-08 —[Removed]

127. Subpart F is amended by removing the following sections: 600.507-08, 600.509-08, 

600.510-08, 600.512-08.

Appendix IV and Appendix V —[Removed]

128. Part 600 is amended by removing and reserving Appendix IV and Appendix V.

PART 1036—CONTROL OF EMISSIONS FROM NEW AND IN-USE HEAVYDUTY HIGHWAY ENGINES

129. The authority citation for part 1036 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart B—[Amended]

130. Section 1036.115 is amended by revising paragraph (b) to read as follows:
Page 726 of 995

§ 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 

131. The authority citation for part 86 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart B – [Amended]

132. 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 
Page 727 of 995

evaporative emission standards. Vehicles up to a certain size that are fueled with gasoline, 

diesel fuel, ethanol, methanol, or LPG are subject to refueling emission standards. 

133. A new §1037.103 is added to read as follows:

§ 1037.103 Evaporative emission standards.

(a) Applicability. Evaporative 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, except that incomplete heavyduty vehicles at or below 14,000 pounds GVWR must meet evaporative emission standards 

as specified in 40 CFR part 86, subpart A through model year 2017. 

(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 emission standards as specified in this section starting in model year 2018. 

(b) Emission standards. The evaporative emission standards specified in 40 CFR 86.1813 

apply for vehicles subject to standards under this section based on emission measurements using 

the procedures specified in §1037.530. These standards phase in over model years 2018 through 

2022. 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).

(c) Compliance demonstration. You may provide a statement in the application for 

certification that vehicles 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 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) 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. 

(e) Useful life. Your vehicles must meet the evaporative emission standards of this 
Page 728 of 995

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.

(f) 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.

134. Section 1037.104 is amended by revising 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]

135. Section 1037.230 is amended by revising paragraph (e) to read as follows:

§ 1037.230 Vehicle families, sub-families, and configurations.

* * * * *
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(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.

* * * * *

136. 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.
Page 730 of 995

Subpart F—[Amended]

137. Section 1037.501 is amended by revising paragraph (a) to read as follows:

§ 1037.501 General testing and modeling provisions.

* * * * *

(a) Use the equipment and procedures specified in §1037.530 to determine whether 

vehicles meet the diurnal, running loss, and hot soak emission standards specified in § 1037.103. 

* * * * *

138. A new §1037.530 is added to subpart F to read as follows:

§ 1037.530 Evaporative emission test procedures.

Apply the provisions of 40 CFR part 86, subpart B, to demonstrate compliance with the 

diurnal, running loss, and hot soak emission standards as specified in §1037.103, with the 

following exceptions: 

(a) Use drive cycles for heavy-duty vehicles as follows:

(1) The Heavy-Duty Urban Dynamometer Driving Schedule (HD-UDDS) is specified 

in 40 CFR part 86, Appendix I, paragraph (d). It represents about 5.6 miles of driving for a 

heavy-duty vehicle in an urban area. 

(2) For the preconditioning drive, operate the vehicle over one HD-UDDS instead of the 

drive specified in 40 CFR 86.132.

(3) For the dynamometer run preceding the diurnal emission test, operate the vehicle over 

one HD-UDDS instead of the FTP driving schedule.

(4) For performing the running loss test and developing fuel tank temperature profiles, 

operate the vehicle over three consecutive HD-UDDS cycles, each separated by two minutes 

if idle operation, instead of the driving specified in 40 CFR 86.134. 

(b) The vehicle may be driven onto the dynamometer, as long as the vehicle is driven at 

minimum throttle and the total time of engine operation in the soak period before the diurnal 

emission test does not exceed 3 minutes.

(c) Testing under this subpart does not require measurement of exhaust emissions. 

Disregard references in 40 CFR part 86, subpart B, 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. 
Page 731 of 995

Part 1065—ENGINE-TESTING PROCEDURES

139. The authority citation for part 1065 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart A—[Amended]

140. 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.

141. Section 1065.15 is amended by revising paragraphs (a) and (b) 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.
Page 732 of 995

(iv) Nonmethane hydrocarbon-equivalent, NMHCE, which results from adjusting NMHC 

mathematically to be equivalent on a carbon-mass basis.

(3) Particulate mass, 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.

* * * * *

142. Section 1065.20 is amended by italicizing the heading for paragraph (g) and revising 

paragraphs (a), (b), and (c) to read as follows:

§1065.20 Units of measure and overview of calculations.

(a) System of units. 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 

§1065.1010. The following exceptions apply:

(1) We designate angular speed, fn, of an engine’s crankshaft in revolutions per minute 

(r/min), rather than the SI unit of radians per second (rad/s). This is based on the commonplace 

use of r/min in many engine dynamometer laboratories.

(2) We designate brake-specific emissions in grams per kilowatt-hour (g/(kW∙hr)), rather 

than the SI unit of grams per megajoule (g/MJ). In addition, we use the symbol hr to identify

hour, rather than the SI convention of using h. This is based on the fact that engines are 

generally subject to emission standards expressed in g/kW·hr. If we specify engine standards in 

grams per horsepowerhour (g/(hp∙hr)) in the standard-setting part, convert units as specified in 

paragraph (d) of this section.

(3) We 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. 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:
Page 733 of 995

(1) For ideal gases, mol/mol, formerly ppm (volume).

(2) For all substances, cm3/m3, formerly ppm (volume).

(3) For all substances, mg/kg, formerly ppm (mass).

(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.

* * * * *

143. Section 1065.25 is revised to read as follows:

§1065.25 Recordkeeping.

The procedures in this part include various requirements to record data or other 

information. Refer to the standard-setting part and §1065.695 regarding recordkeeping 

requirements. You must promptly send us organized, written records in English if we ask for 

them. We may review them at any time.

Subpart B—[Amended]

144. Section 1065.130 is amended by revising paragraph (a) 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.

* * * * *

145. Section 1065.140 is revised to read as follows:

§1065.140 Dilution for gaseous and PM constituents.

(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 
Page 734 of 995

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 1066.620 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 select a tubing material that is not 

prone to leaks, and configure the tubing to ensure smooth flow at the CVS flow meter. 
Page 735 of 995

(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 
Page 736 of 995

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 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.
Page 737 of 995

(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 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 steady-state 

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 
Page 738 of 995

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).

(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).
Page 739 of 995

(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.

146. Section 1065.145 is amended by revising paragraphs (a), (c), (d), and (e) 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) Gaseous and PM sample probes. A probe is the first fitting in a sampling system. It 

protrudes into a raw or diluted exhaust stream to extract a sample, such that its inside and outside 

surfaces are in contact with the exhaust. A sample is transported out of a probe into a transfer 

line, as described in paragraph (d) of this section. The following provisions apply to sample 

probes: 

(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) Gaseous sample probes. Use either single-port or multi-port probes for sampling 

gaseous emissions. You may orient these probes in any direction relative to the raw or diluted 

exhaust flow. For some probes, you must control sample temperatures, as follows:
Page 740 of 995

(i) For probes that extract NOx from diluted exhaust, control the probe’s wall temperature 

to prevent aqueous condensation. 

(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 four-stroke sparkignition 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.

(3) PM sample probes. Use PM probes with a single opening at the end. Orient PM 

probes to face directly upstream. If you shield a PM probe’s opening with a PM pre-classifier 

such as a hat, you may not use the preclassifier we specify in paragraph (f)(1) of this section. 

We recommend sizing the inside diameter of PM probes to approximate isokinetic sampling at 

the expected mean flow rate.

(d) Transfer lines. You may use transfer lines to transport an extracted sample from a 

probe to an analyzer, storage medium, or dilution system, noting certain restrictions for PM 

sampling in §1065.140(e). Minimize the length of all transfer lines by locating analyzers, 

storage media, and dilution systems as close to probes as practical. We recommend that you 

minimize the number of bends in transfer lines and that you maximize the radius of any 

unavoidable bend. Avoid using 90elbows, tees, and cross-fittings in transfer lines. Where such 

connections and fittings are necessary, take steps, using good engineering judgment, to ensure 

that you meet the temperature tolerances in this paragraph (d). This may involve measuring 

temperature at various locations within transfer lines and fittings. You may use a single transfer 

line to transport a sample of more than one constituent, as long as the transfer line meets all the 

specifications for each constituent. The following construction and temperature tolerances apply 

to transfer lines:

(1) Gaseous samples. Use transfer lines with inside surfaces of 300 series stainless steel, 

PTFE, VitonTM, or any other material that you demonstrate has better properties for emission 

sampling. For raw exhaust sampling, use a non-reactive material capable of withstanding raw 

exhaust temperatures. You may use in-line filters if they do not react with exhaust constituents 

and if the filter and its housing meet the same temperature requirements as the transfer lines, as 

follows:

(i) For NOx transfer lines upstream of either an NO2-to-NO converter that meets the 

specifications of §1065.378 or a chiller that meets the specifications of §1065.376, maintain a 

sample temperature that prevents aqueous condensation.

(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 
Page 741 of 995

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.

(2) PM samples. We recommend heated transfer lines or a heated enclosure to minimize 

temperature differences between transfer lines and exhaust constituents. Use transfer lines that 

are inert with respect to PM and are electrically conductive on the inside surfaces. We 

recommend using PM transfer lines made of 300 series stainless steel. Electrically ground the 

inside surface of PM transfer lines.

(e) Optional sample-conditioning components for gaseous sampling. You may use the 

following sample-conditioning components to prepare gaseous samples for analysis, as long as 

you do not install or use them in a way that adversely affects your ability to show that your 

engines comply with all applicable gaseous emission standards.

(1) NO2-to-NO converter. You may use an NO2-to-NO converter that meets the 

converter conversion verification specified in §1065.378 at any point upstream of a NOx

analyzer, sample bag, or other storage medium.

(2) Sample dryer. You may use either type of sample dryer described in this paragraph 

(e)(2) to decrease the effects of water on gaseous emission measurements. You may not use a 

chemical dryer, or use dryers upstream of PM sample filters.

(i) Osmotic-membrane. You may use an osmotic-membrane dryer upstream of any

gaseous analyzer or storage medium, as long as it meets the temperature specifications in 

paragraph (d)(1) of this section. Because osmotic-membrane dryers may deteriorate after 

prolonged exposure to certain exhaust constituents, consult with the membrane manufacturer 

regarding your application before incorporating an osmotic-membrane dryer. Monitor the 

dewpoint, Tdew, and absolute pressure, ptotal, downstream of an osmotic-membrane dryer. You 

may use continuously recorded values of Tdew and ptotal in the amount of water calculations 

specified in §1065.645. 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 amount of water calculations specified in 

§1065.645. For your testing, you may use the maximum temperature or minimum pressure 

values observed during a test interval or duty cycle or the high alarm temperature setpoint or low 

alarm pressure setpoint as constant values in the 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.

(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 four-stroke 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 lossperformance 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 
Page 742 of 995

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) Sample pumps. You may use sample pumps upstream of an analyzer or storage 

medium for any gas. Use sample pumps with inside surfaces of 300 series stainless steel, PTFE, 

or any other material that you demonstrate has better properties for emission sampling. For some 

sample pumps, you must control temperatures, as follows:

(i) If you use a NOx sample pump upstream of either an NO2-to-NO converter that meets 

§1065.378 or a chiller that meets §1065.376, it must be heated to prevent aqueous condensation.

(ii) For testing compression-ignition engines, 2-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.

(4) Ammonia Scrubber. You may use ammonia scrubbers for any or all gaseous 

sampling systems to prevent interference with NH3, poisoning of the NO2-to-NO converter, and 

deposits in the sampling system or analyzers. Follow the ammonia scrubber manufacturer’s 

recommendations or use good engineering judgment in applying ammonia scrubbers.

* * * * *

147. Section 1065.170 is amended by revising paragraphs (a)(1), (b), and (c)(1)(i) 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 
Page 743 of 995

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.

* * * * *

(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 four-stroke 

spark-ignition engines at or below 19 kW. For all other engines and pollutants, these materials 

are good for sample temperatures up to 202 °C.
Page 744 of 995

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.

* * * * *

Subpart C—[Amended]

148. Section 1065.201 is amended by revising paragraphs (b), (d), (e), and (h) to read as 

follows:
Page 745 of 995

§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 engine’s known or assumed 

fuel properties. 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.

149. 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. Use 
Page 746 of 995

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

Appl

icable Test 

Protocol 

Section

Measured Values

Mini

mum 

Command and 

Control 

Frequency

Minim

um Recording 

Frequency

§106

5.510

Speed and torque during an engine stepmap

1 Hz 1 mean 

value per step

§106

5.510

Speed and torque during an engine sweepmap

5 Hz 1 Hz 

means

§106

5.514

§106

5.530

Transient duty cycle reference and feedback 

speeds and torques 5 Hz 1 Hz means

§106

5.514

§106

5.530

Steady-state and ramped-modal duty cycle 

reference and feedback speeds and torques 1 Hz 1 Hz

§106

5.520

§106

5.530

§106

5.550

Continuous concentrations of raw or dilute 

analyzers N/A 1 Hz

§106

5.520

§106

5.530

Batch concentrations of raw or dilute 

analyzers N/A

1 mean 

value per test 

interval
Page 747 of 995

§106

5.550

§106

5.530

§106

5.545

Diluted exhaust flow rate from a CVS with 

a heat exchanger upstream of the flow measurement N/A 1 Hz

§106

5.530

§106

5.545

Diluted exhaust flow rate from a CVS 

without a heat exchanger upstream of the flow 

measurement

N/A 1 Hz 

means

§106

5.530

§106

5.545

Intake-air or raw-exhaust flow rate N/A 1 Hz 

means

§106

5.530

§106

5.545

Dilution air if actively controlled 5 Hz 1 Hz 

means

§106

5.530

§106

5.545

Sample flow from a CVS that has a heat 

exchanger 1 Hz 1 Hz

§106

5.530

§106

5.545

Sample flow from a CVS does not have a 

heat exchanger 5 Hz 1 Hz means

150. Section 1065.205 is amended by revising the introductory text to read as follows:

§1065.205 Performance specifications for measurement instruments.
Page 748 of 995

Your test system as a whole must meet all the calibrations, verifications, and testvalidation criteria specified outside of 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.

* * * * *

151. 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.

* * * * *

152. Section 1065.230 is amended by revising paragraph (d) to read as follows:
Page 749 of 995

§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, two-stroke 

spark-ignition engines, or four-stroke spark-ignition engines at or below 19 kW.

(3) The cooling must not cause aqueous condensation.

153. 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, two-stroke 

spark-ignition engines, or four-stroke spark-ignition engines at or below 19 kW.

(3) The cooling must not cause aqueous condensationas described in §1065.140(c)(6).

154. 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.
Page 750 of 995

HYDROCARBON MEASUREMENTS

155. 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 1066.665 for methods to demonstrate compliance with NMOG standards for vehicle 

testing.

(f) CH4. For reporting CH4 or for demonstrating compliance with CH4 standards, you 

may use a FID analyzer with a nonmethane cutter as described in §1065.265 or you may use a 

GC-FID as described in §1065.267. Determine CH4 as described in §1065.660(c).

156. 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 SAE 

J1151 (incorporated by reference in §1065.1010). The GC-FID must meet the linearity

verification in §1065.307.

157. A new §1065.269 is added to subpart C to read as follows:
Page 751 of 995

§1065.269 Photoacoustic analyzer for methanol and ethanol.

(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 calibration and verifications 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.

NOx AND N2O MEASUREMENTS

158. 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.

* * * * *

159. 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.

* * * * *
Page 752 of 995

160. 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).

(3) Laser infrared analyzer. Examples of laser infrared analyzers are pulsed-mode highresolution narrow band mid-infrared analyzers, and modulated continuous wave high-resolution 

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 polystyrene-divinylbenzene 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.

* * * * *

O2 MEASUREMENTS
Page 753 of 995

161. 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.

AIR-TO-FUEL RATIO MEASUREMENTS

162. 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.

PM MEASUREMENTS

163. 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 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]
Page 754 of 995

164. 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 
Page 755 of 995

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 

system-response 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.

§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.
Page 756 of 995

§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 O2

interference

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 
Page 757 of 995

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.

165. Section 1065.305 is amended by revising paragraph (d)(10)(i) to read as follows:

§1065.305 Verifications for accuracy, repeatability, and noise.

* * * * *

(d) * * *

(10) * * *

(i) Your measurement systems meet all the other required calibration, verification, and 

validation specifications that apply as specified in the regulations.

* * * * *

166. 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.
Page 758 of 995

(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 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) 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.

(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 
Page 759 of 995

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, iy . 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, iy , 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, iy )), 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 calibration reference quantities that are NISTtraceable 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 torquemeasurement system. In this case, use the reference load cell measurement as the reference 
Page 760 of 995

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, or for current and voltage. 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 by the flow-meter manufacturer 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 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 gas-division 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, 
Page 761 of 995

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-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.

(9) Mass. For linearity verification for gravimetric PM balances, use external calibration 

weights that 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, 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:
Page 762 of 995

(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 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.
Page 763 of 995

(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.

(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.

(C) Barometer.

(D) CVS inlet gage pressure.

(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.
Page 764 of 995

Table 1 of §1065.307–Measurement systems that require linearity verification.

Measurem

ent system

Q

uantity

Linearity criteria

|

xmin(a1-1)+a0 |

a

1

SEE r

2

Speed f

n

≤ 0.05 

% ∙ nmax f

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 % ∙ 

Umax

0

.98-1.02

≤ 2 % ∙ 

Umax

≥ 

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 n ≤ 1 % ∙ 0 ≤ 2 % ∙ ≥ 
Page 765 of 995

exhaust

flow rate1

max n .98-1.02 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

Pressures p

≤ 1 % ∙ 

max p

0

.99-1.01

≤ 1 % ∙ 

max p

≥ 

0.998

Dewpoint 

for intake air, PMstabilization and 

balance 

environments

T

dew

≤ 0.5 

% ∙ Tdewmax

0

.99-1.01

≤ 0.5 

% ∙ Tdewmax

≥ 

0.998

Other 

dewpoint 

measurements

T

dew

≤ 1 % ∙ 

Tdewmax

0

.99-1.01

≤ 1 % ∙ 

Tdewmax

≥ 

0.998

Analog-todigital 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 .
Page 766 of 995

167. Section 1065.308 is amended by revising paragraph (d) 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) Procedure. Use the following procedure to verify the response of each continuous gas 

analyzer:

(1) Instrument setup. Follow the analyzer manufacturer’s start-up and operating 

instructions. Adjust the measurement system as needed to optimize performance. Run this 

verification with the analyzer operating in the same manner you will use for emission testing. If 

the analyzer shares its sampling system with other analyzers, and if gas flow to the other 

analyzers will affect the system response time, then start up and operate the other analyzers while 

running this verification test. You may run this verification test on multiple analyzers sharing 

the same sampling system at the same time. If you use any analog or real-time digital filters 

during emission testing, you must operate those filters in the same manner during this 

verification.

(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 multigas 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.

(3) Data collection. (i) Start the flow of zero gas.

(ii) Allow for stabilization, accounting for transport delays and the slowest analyzer’s full 

response.
Page 767 of 995

(iii) Start recording data. For this verification you must record data at a frequency greater 

than or equal to that of the updating-recording frequency used during emission testing. You may

not use interpolation or filtering to alter the recorded values.

(iv) Switch the flow to allow the blended span gases to flow to the analyzer. If you 

intend to use the data from this test to determine t50 for time alignment, record this time as t0.

(v) Allow for transport delays and the slowest analyzer’s full response.

(vi) Switch the flow to allow zero gas to flow to the analyzer. If you intend to use the 

data from this test to determine t50 for time alignment, record this time as t100.

(vii) Allow for transport delays and the slowest analyzer’s full response.

(viii) Repeat the steps in paragraphs (d)(3)(iv) through (vii) of this section to record seven 

full cycles, ending with zero gas flowing to the analyzers.

(ix) Stop recording.

* * * * *

(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 (such as 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 (such as 

a raw exhaust stack), you must adjust the span gas flow rate to be less than the sample flow rate 

so ambient air is always drawn into the probe inlet. This avoids errors associated with 

overflowing span gas out of the probe inlet and drawing the span gas back in when sampling 

ambient air.

(3) When sampling ambient air with or without 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 response rise and stabilized reading, followed by switching back to 

purified N2 and observing the analyzer’s response fall and stabilized reading.
Page 768 of 995

168. 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 ramped-modal 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 1066.640 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 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
Page 769 of 995

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 NOCO-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 

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.

MEASUREMENT OF ENGINE PARAMETERS AND AMBIENT CONDITIONS

169. Section 1065.310 is amended by revising paragraph (d) to read as follows:

§1065.310 Torque calibration.
Page 770 of 995

* * * * *

(d) 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 torque-measuring 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 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.

170. 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.

* * * * *

171. 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 
Page 771 of 995

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 1066.610 for vehicle testing) and §1065.660, using the molar mass of C3H8, MC3H8, 

instead the effective molar mass of HC, MHC.

* * * * *

172. Section 1065.350 is amended by revising paragraphs (d) and (e) 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 
Page 772 of 995

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) Exceptions. The following exceptions apply:

(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 % 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.

(2) You may use a CO2 NDIR analyzer that you determine does not meet this 

verification, as long as you try to correct the problem and the measurement deficiency does not 

adversely affect your ability to show that engines comply with all applicable emission standards.

173. Section 1065.355 is amended by revising paragraph (d) to read as follows:

§1065.355 H2O and CO2 interference verification for CO NDIR analyzers.

* * * * *

(d) Procedure. Perform the interference verification as follows:

(1) Start, operate, zero, and span the CO 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 
Page 773 of 995

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 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.

(3) Introduce the humidified CO2 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 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.

(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.

(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 for CO2 and H2O separately. If the CO2

and H2O levels used are higher than the maximum levels expected during testing, you may scale 

down each observed interference value 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 
Page 774 of 995

H2O concentration value to the actual value used during this procedure. The sum of the two 

scaled interference values must meet the tolerance in paragraph (c) of this section.

* * * * *

HYDROCARBON MEASUREMENTS

174. Section 1065.360 is amended by revising paragraphs (a)(3), (b), (d), (e) introductory text, 

and (e)(4) 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 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[THC-FID], 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.
Page 775 of 995

(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[THC-FID].

(e) THC FID CH4 response verification. This procedure is only for FID analyzers that 

measure THC. If the value of RFCH4[THC-FID] from paragraph (d) of this section is within 5 % of 

its most recent 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 changed by 

0.05 to become 1.10 or it changed by -0.05 to become 1.00, either case would be acceptable 

because 4.8 % is less than 5 %. Verify RFCH4[THC-FID] as follows:

* * * * *

(4) For analyzers with multiple ranges, you need to perform the procedure in this 

paragraph (e) only on a single range.

* * * * *

175. Section 1065.362 is amended by adding paragraph (d)(15) to read as follows:
Page 776 of 995

§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. 

176. 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 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.

* * * * *
Page 777 of 995

(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.

* * * * *

177. A new §1065.369 is added to subpart D 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 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.
Page 778 of 995

(d) Procedure. Perform the interference verification by following the procedure in 

§1065.375(d), comparing the results to paragraph (c) of this section.

NOx AND N2O MEASUREMENTS

178. 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.

* * * * *

179. Section 1065.375 is amended by revising paragraph (d) to read as follows:

§1065.375 Interference verification for N2O analyzers.
Page 779 of 995

* * * * *

(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 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.
Page 780 of 995

(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 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.

180. Section 1065.376 is amended by revising paragraphs (b) and (d)(2) 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) Equipment setup and data collection. (i) Zero and span the total NOx gas analyzer(s) 

as you would before emission testing. 

(ii) Select an NO2 calibration gas, balance gas of dry air, that has an NO2 concentration 

within ±5 % of the maximum NO2 concentration expected during testing.

(iii) Overflow this calibration gas at the gas sampling system’s probe or overflow fitting. 

Allow for stabilization of the total NOx response, accounting only for transport delays and 

instrument response.

(iv) Calculate the mean of 30 seconds of recorded total NOx data and record this value as 

xNOxref.

(v) Stop flowing the NO2 calibration gas.
Page 781 of 995

(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.

(vii) Immediately switch back to overflowing the NO2 calibration gas used to establish 

xNOxref. Allow for stabilization of the total NOx response, accounting only for transport delays 

and instrument response. Calculate the mean of 30 seconds of recorded total NOx data and 

record this value as xNOxmeas. 

(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]

181. Section 1065.405 is amended by revising paragraph (a) and adding paragraph (f) 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 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 components to simulate an inuse 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.

* * * * *

(f) This paragraph (f) 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 (f)(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. An engine-related component 
Page 782 of 995

meeting all 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 the control 

of 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.

(iii) The component is not part of the laboratory setup, or it is used for other engines. 

(2) Although components meeting the criteria specified in paragraphs (f)(1)(i) or (ii) of 

this section, but not the criterion specified in paragraph (f)(1)(iii) of this section, are not 

considered to be part of the test engine, you must precondition these components along with the 

test engine.

Subpart F—[Amended]

182. Section 1065.501 is amended as follows:

a. By redesignating paragraphs (b) through (d) as paragraphs (c) through (e), respectively.

b. By adding a new paragraph (b).

c. By revising the redesignated paragraph (c)(2) introductory text.

§1065.501 Overview.

* * * * *

(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 would also allow you to ensure that a regeneration event does not 

occur during an emission test.

(c) * * *

(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 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:
Page 783 of 995

* * * * *

183. A new §1065.516 is added to subpart E 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. A sampling system is considered decontaminated if the 

contaminants are in equilibrium with measured exhaust emissions. Note that although this 

section focuses on avoiding excessive contamination of sample systems, you must also use good 

engineering judgment to avoid loss of sample to a sample system that is too clean. The goal of 

decontamination is not to perfectly clean the sample system, but rather to achieve equilibrium 

between the sample system and the exhaust so emission components are neither lost to nor 

entrained from the sample system.

(a) You may perform contamination checks as follows to determine if decontamination is 

needed:

(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 wet, net 

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/decontaminate sampling systems, use the following recommended 

procedure or use good engineering judgment to select a different procedure:

(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.
Page 784 of 995

(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.

184. A new §1065.518 is added to subpart E 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. We may test 

your engine after completing only the minimum amount of preconditioning recommended in this 

section. For subsequent testing, such as steady-state testing following transient testing, we may

consider the previous test cycle as preconditioning. 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 

over the duty cycle, as described in §1065.10(c)(1), by conditioning the engine to a state where 

its emissions are representative of in-use operation.

(c) This paragraph (c) specifies the engine preconditioning procedures for different types 

of duty cycles. You may measure emissions during preconditioning cycles, as long as you 

perform a predefined number of preconditioning cycles. You must identify before each duty

cycle whether it is a preconditioning cycle or an emission test. You may not abort an emission 

test based on emissions measured during preconditioning.

(1) Cold-start transient cycle. Precondition the engine by running at least one cold-start 

or hot-start transient cycle. Immediately after completing the last preconditioning cycle, shut 

down the engine and begin the cold soak as described in §1065.530(a)(1).
Page 785 of 995

(2) Hot-start transient cycle. Precondition the engine by running at least one hot-start 

transient cycle. Shut down the engine after completing the last preconditioning cycle and start 

the hot-start transient test as soon as practical.

(3) Hot-running transient cycle. Precondition the engine by running at least one hotrunning transient cycle. Start the official hot-running transient cycle as soon as practical after 

completing the last preconditioning cycle.

(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 sampling 

time limits.

(5) Ramped-modal cycle for steady-state testing. If you run the ramped-modal cycle after 

a transient test, additional preconditioning is allowed, but not required. If you perform additional 

preconditioning, we recommend running the first non-idle mode of the ramped-modal cycle or a 

mode approximating 50 % power.

(d) You may conduct calibrations or verifications on any idle equipment or analyzers 

during engine preconditioning.

185. Section 1065.520 is amended by removing paragraph (g) and revising paragraphs (a), 

(e), and (f) 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.

* * * * *

(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 train 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:
Page 786 of 995

(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.

(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), (3), (7)(i), and (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 wet, net concentration expected at the HC (THC or 

NMHC) standard.
Page 787 of 995

(ii) 2 % of the flow-weighted mean wet, net 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.

186. Section 1065.526 is amended by revising paragraphs (c)(3) and (d)(1) to read as follows:

§1065.526 Repeating of void modes or test intervals.

* * * * *

(c) * * *

(3) Precondition the engine by operating it at the mode at which the test was interrupted 

and continue with the duty cycle as specified in the standard-setting part.

(d) * * * * *

(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.

* * * * *

187. Section 1065.530 is amended by removing paragraph (b)(13) and revising paragraphs 

(a), (b)(12), 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 remove heat from coolant 

through the engine cooling system, and to remove heat from any exhaust aftertreatment systems. 
Page 788 of 995

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, immediately after completing the last 

preconditioning cycle, shut down the engine and as soon as practical start the official hot-start 

transient cycle. We will start the official hot-start transient cycle within 1 minute of the 

conclusion of the preconditioning cycle where applicable. Start the hot-start duty cycle as 

specified in the standard-setting part if it is different from this procedure. 

(iii) For testing that involves hot-stabilized emission measurements, such as any steadystate testing, as soon as practical after completing the discrete-mode preconditioning time or the 

last preconditioning cycle, without shutting down the engine, start the official hot-stabilized 

cycle. We will start the official hot-stabilized cycle within 1 minute of the conclusion of the 

preconditioning cycle where applicable. If the last preconditioning cycle ends with a different 

operating condition than the first mode of the hot-stabilized cycle, add a linear transition period 

of 20 s between cycles where you linearly ramp the (denormalized) reference speed and torque 

values over the transition period.

(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 emission measurements, 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) * * *

(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 
Page 789 of 995

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 testing as follows:

(1) If engine starting is not part of the duty cycle, perform the following for the various 

duty cycles:

(i) Transient and steady-state ramped-modal cycles. Simultaneously start recording 

continuous data, any electronic integrating devices, batch sampling, and execution of the duty 

cycle.

(ii) Steady-state discrete-mode cycles. Control the engine operation to match the first 

mode in the test cycle. This will require controlling engine speed and load, engine load, or other 

operator demand settings, as specified in the standard-setting part. Follow the instructions in the 

standard-setting part to determine how long to stabilize engine operation at each mode, how long 

to sample emissions at each mode, and how to transition between modes. For each mode, 

simultaneously start recording continuous data, any electronic integrating devices, and batch 

sampling.

(2) If engine starting is part of the duty cycle, simultaneously start recording continuous 

data, any electronic integrating devices, and batch sampling before attempting to start the 

engine. Initiate the duty cycle when the engine starts.

(3) For batch sampling systems you may use good engineering judgment to advance or 

delay the start and stop of sampling with respect to the beginning and end of the test interval to 

improve the accuracy of the batch sample.

* * * * *

188. 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.
Page 790 of 995

(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 criticalflow 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.

189. 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):

* * * * *

190. 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:
Page 791 of 995

(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 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.
Page 792 of 995

(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 brake-specific 

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 corrected values, you 

may consider the data to be verified for demonstrating compliance with the applicable standard.

Subpart G—[Amended]
Page 793 of 995

191. 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. We allow weighted 

means where appropriate. You may discard statistical outliers, but you must report all results.

* * * * *

192. Section 1065.630 is revised to read as follows:

§1065.630 1980 international gravity formula.

The acceleration of Earth's gravity, ag, varies depending on your location. Calculate ag at 

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

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

193. Section 1065.640 is amended by revising paragraphs (a), (b), and (e) to read as follows:

§1065.640 Flow meter calibration calculations.

* * * * *
Page 794 of 995

(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.

&

stdref

V = reference volume flow rate, corrected to a standard pressure and a standard 

temperature.

&

actref V = reference volume flow rate at the actual pressure and temperature of the flow rate.

m&ref = 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

pstd = 29.9213 in Hg @ 32 °F = 101325 Pa

Tstd = 68.0 °F = 293.15 K
Page 795 of 995

R = 8.314472 J/(mol∙K)

ref

0.471948 101325

293.15 8.314472

n









ref n& = 19.619 mol/s

Example 2: 

m&ref = 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)

Tin = 299.5 K

in p = 98290 Pa

nPDP f = 1205.1 r/min = 20.085 r/s

25.096 8.314472 299.5

98290 20.085

Vrev

 




Page 796 of 995

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

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:
Page 797 of 995

Table 1 of §1065.640–

Example of PDP calibration data

nPDP f

(r/

min)

a1 

(m3/min)

a0 

(m3/r)

75

5.0

50

.43

0.

056

98

7.6

49

.86

-

0.013

12

54.5

48

.54

0.

028

14

01.3

47

.30

-

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.

* * * * *

(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 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 of 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. 
Page 798 of 995

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.

194. Section 1065.642 is amended by revising paragraphs (a) and (c) to read as follows:

§1065.642 SSV, CFV, and PDP molar flow rate calculations.

* * * * *

(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:
Page 799 of 995

nPDP

in rev

in

p V n f

R T



 





Eq. 1065.642-1

Where:

nPDP

1 out in

rev 0

out

a p p V a

f p



  

Eq. 1065.642-2

Example:

a1 = 50.43 (m3/min) = 0.8405 (m3/s)

fnPDP = 755.0 r/min = 12.58 r/s

pout = 99950 Pa

pin = 98575 Pa 

a0 = 0.056 (m3/r)

R = 8.314472 J/(mol∙K)

Tin = 323.5 K

Cp = 1000 (J/m3)/kPa

Ct = 60 s/min

rev

0.8405 99950 98575 0.056

12.58 99950

V



  

Vrev = 0.06383 m3/r

98575 0.06383 12.58

8.314472 323.5

n



 





n&= 29.428 mol/s

* * * * *
Page 800 of 995

(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 of 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 = 98836 Pa

Z = 1

Mmix = 28.7805 g/mol = 0.0287805 kg/mol

R = 8.314472 J/(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 choose to follow the 

permissible ranges of dilution air dewpoint versus calibration air dewpoint in Table 3 of 
Page 801 of 995

§1065.640, you may set Mmix-cal and Mmix equal to 1. Calculate n as follows:

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 = volumetric flow 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 = 99654 Pa

pin = 98836 Pa

pstd = 101325 Pa

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
Page 802 of 995

R = 8.314472 J/(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

195. 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 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
Page 803 of 995

Where:

pH20 = 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(pH20) = 0.074297

pH20 = 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:

Tice = –15.4 °C = 257.75 K
Page 804 of 995

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

pH20 = 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(pH20) = 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,

pH20sat = 2.3371 kPa
Page 805 of 995

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

196. Section 1065.650 is amended by revising paragraph (c)(1) to read as follows:

§1065.650 Emission calculations.

* * * * *

(c) * * *

(1) Concentration corrections. Perform the following sequence of preliminary 

calculations on recorded concentrations:

(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.

(iii) Correct all concentrations measured on a “dry” basis to a “wet” basis, including 

dilution air background concentrations, as described in §1065.659.

(iv) Calculate all NMHC and CH4 concentrations, including dilution air background 

concentrations, as described in §1065.660.

(v) For emission testing with an oxygenated fuel, calculate any HC concentrations, 

including dilution air background concentrations, as described in §1065.665. See subpart I of 

this part for testing with oxygenated fuels.

(vi) Correct all the NOx concentrations, including dilution air background concentrations, 

for intake-air humidity as described in §1065.670.

* * * * *
Page 806 of 995

197. 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 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 paragraphs (d)(1) or (d)(2) of this section, 

or you may use default values for a given fuel as described in §1065.655(d)(3). 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.
Page 807 of 995

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 

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





        
Page 808 of 995

Eq. 1065.655-19

Where:

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
Page 809 of 995

MH = 1.00794

MO = 15.9994

MS = 32.065

MN = 14.0067

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 for liquid fuels as follows:

(A) You may determine the fuel 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 from gasoline (with or without blended ethanol), use good 

engineering judgment to adapt the method as appropriate.

(B) Determine oxygen mass fraction for 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 

measured values using the following equations:

H C

C H

w M

w M









 

Eq. 1065.655-20
Page 810 of 995

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.

Example:
Page 811 of 995

wC = 0.8206

wH = 0.1239

wO = 0.0547

wS = 0.00066

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
Page 812 of 995

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.

(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 steady-state 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
Page 813 of 995

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 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 flow rate including humidity in intake air.

Example:

mfuel  = 7.559 g/s
Page 814 of 995

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 nexh  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

0.1451mol/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  .371mol/s

198. Section 1065.659 is amended by revising paragraph (a) 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 
Page 815 of 995

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 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.

* * * * *

199. 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

dexhOHCi

OHCi dexhOHCi

OHCi

dexh dexh

dexh

m

M n

x

m n

M

 

Eq. 1065.665-3
Page 816 of 995

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.
Page 817 of 995

(c) The following example shows how to determine NMHCE emissions based on ethanol 

(C2H5OH), methanol (CH3OH), acetaldehyde (C2H4O), and formaldehyde (HCHO) 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

xHCHO = 1.3 μmol/mol

RFCH4[THC-FID] = 1.07

RFC2H5OH[THC-FID] = 0.76

RFCH3OH[THC-FID] = 0.74

RFH2H4O[THC-FID] = 0.50

RFHCHO[THC-FID] = 0.0

xNMHCE = xTHC[THC-FID]cor – (xC2H5OH  RFC2H5OH[THC-FID] + xCH3OH  RFCH3OH[THC-FID] + 

xC2H4O  RFC2H4O[THC-FID] + xHCHO  RFHCHO[THC-FID] + xC2H5OH + xCH3OH + xC2H4O + xHCHO –

(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

200. 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.
Page 818 of 995

* * * * *

(6) * * *

(x) Number and type of preconditioning cycles.

* * * * *

Subpart H—[Amended]

201. 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 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 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:
Page 819 of 995

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

Motor vehicle gasoline ASTM D4814

Motor gasoline with 

ethanol concentrations 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.

202. Section 1065.703 is amended by revising Table 1 to read as follows:

§1065.703 Distillate diesel fuel.
Page 820 of 995

* * * * *
Page 821 of 995

Table 1 of §1065.703–Test fuel specifications for distillate diesel fuel

Property nit

U

ltra Low

S

ulfur

L

ow

S

ulfur

Hi

gh

Su

lfur

Reference

Procedure1

Cetane Number 4

0 - 50

4

0 - 50

40 

- 50

ASTM 

D613

Distillation range:

Initial boiling point

10 pct. point 

50 pct. point

90 pct. point 

Endpoint

C

1

71 - 204

2

04 - 238

2

43 - 282

2

93 - 332

3

21 - 366

1

71 - 204

2

04 - 238

2

43 - 282

2

93 - 332

3

21 - 366

17

1 - 204

20

4 - 238

24

3 - 282

29

3 - 332

32

1 - 366

ASTM D86

Gravity

API

3

2 - 37

3

2 - 37

32 

- 37

ASTM 

D4052

Total sulfur, ultra low sulfur

g/kg

7 

– 15

See 40 

CFR 80.580

Total sulfur, low and high 

sulfur g/kg

3

00 - 500

80

0 - 2500

ASTM 

D2622or alternates 

as allowed under 40 

CFR 80.580

Aromatics, min. (Remainder 

shall be paraffins, naphthenes, and 

olefins)

/kg

1

00

1

00

10

0

ASTM 

D5186

Flashpoint, min.

C

5

4

5

4

54 ASTM D93
Page 822 of 995

Kinematic Viscosity

St

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.

203. 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 lowtemperature 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

15 % ethanol (commonly called E15 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:

Table 1 of §1065.710–Test fuel specifications for a low-level ethanol-gasoline blend

Property Unit SPECIFICATION Referenc
Page 823 of 995

G

eneral 

Testing

Lo

wTemperature 

Testing

Hig

h Altitude 

Testing

e Procedure1

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

kPa 

(psi)

6

0.0-63.4 

(

8.7-9.2)

77.2

-81.4

(11.

2-11.8)

52.4

-55.2 

(7.6

-8.0)

ASTM 

D5191

Distillation

10% 

evaporated

°C 

(°F)

4

9-60

(120-140)

43-

54 

(11

0-130)

49-

60

(120-140)

ASTM 

D86

50% 

evaporated

°C 

(°F) 77-88 (170-190)

90% 

evaporated

°C 

(°F) 154-166 (310-330)

Evaporated 

final boiling point

°C 

(°F) 193-216 (380-420)

Residue mill

iliter 2.0 Maximum

Total 

Aromatic 

Hydrocarbons

volu

me % 19.5-24.5

ASTM 

D5769 C6 

Aromatics (benzene)

volu

me % 0.6-0.8

C7 

Aromatics (toluene)

volu

me % 4.4-5.5
Page 824 of 995

C8 

Aromatics

volu

me % 5.5-6.9

C9 

Aromatics

volu

me % 5.0-6.2

C10+ 

Aromatics 

volu

me % 4.0-5.0

Olefins4 mas

s % 4.5-11.5 ASTM D6550

Ethanol 

blended5

volu

me % 14.6-15.0

See 

paragraph (b)(3) of 

this section.

Ethanol 

confirmatory

6,7

volu

me % 14.3-15.3 ASTM D5599

Total 

Content of 

Oxygenates Other 

than Ethanol7

volu

me % 0.1 Maximum ASTM D5599

Sulfur mg/

kg 8.0-11.0

ASTM 

D2622, D5453 or 

D7039

Lead g/lit

er

0.0026 Maximum ASTM 

D3237

Phosphorus g/lit

er

0.0013 Maximum ASTM 

D3231

Copper 

Corrosion - No. 1 Maximum ASTM D130

SolventWashed Gum 

Content

mg/

100 milliliter 3.0 Maximum ASTM D381

Oxidation 

Stability

min

ute 1000 Minimum ASTM D525
Page 825 of 995

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, in 

kPa using the following equation: DVPE = 0.956∙pT - 2.39. DVPE is intended to be equivalent to Reid Vapor 

Pressure using a different test method.

4The specified olefin concentration range equates to approximately 4 – 10 volume % when measured 

according to ASTM D1319.

5The ethanol blended specification 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.

6The ethanol confirmatory specification is based on the volume % ethanol as measured according to 

ASTM D5599.

7The reference procedure prescribes measurement of ethanol concentration in mass %. Convert 

results to volume % as specified in ASTM D4815.

(3) 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

Prope

rty Unit

SPECIFICATION

Reference 

Procedure1

General 

Testing

LowTemperature Testing

Distill

ation Range:

Evap

°C

24 - 35 2 24 - 36

ASTM 

D86
Page 826 of 995

orated initial 

boiling point

10% 

evaporated

50% 

evaporated

90% 

evaporated

Evap

orated final 

boiling point

49 - 57

93 - 110

149 - 163

Maximum, 

213

37 - 48

82 - 101

158 - 174

Maximum, 212

Hydr

ocarbon 

composition:

Olefi

ns

Arom

atics

Satur

ates

volu

me %

Maximum, 

0.10

Maximum, 

0.35

Remainder

Maximum, 0.175

Maximum, 0.304

Remainder

ASTM 

D1319

Lead g/lite

r

Maximum, 

0.013 Maximum, 0.013 ASTM D3237

Phosp

horous

g/lite

r

Maximum, 

0.0013 Maximum, 0.005 ASTM D3231

Total 

sulfur

mg/k

g

Maximum, 

80 Maximum, 80 ASTM D2622

Dry

vapor pressure 

equivalent2

kPa 60.0 -

63.43,4 77.2 - 81.4 ASTM D5191

1ASTM procedures are incorporated by reference in §1065.1010. See §1065.701(d) for other 

allowed procedures.

2Calculate dry vapor pressure equivalent, DVPE, based on the measured total vapor pressure, pT, in 

kPa using the following equation: DVPE = 0.956∙pT - 2.39. DVPE is intended to be equivalent to Reid 
Page 827 of 995

Vapor Pressure using a different test method.

3

For testing at altitudes above 1 219 m, the specified volatility range is (52.0 to 55.2) kPa and the 

specified initial boiling point range is (23.9 to 40.6) °C.

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.

204. 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:
Page 828 of 995

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.

* * * * *

205. 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:
Page 829 of 995

Table 1 of §1065.720–Test fuel specifications for liquefied petroleum gas

Property Value Reference 

Procedure1

Propane, C3H8 Minimum, 0.85 

m

3

/m3

ASTM D2163

Vapor pressure at 38 °C Maximum, 1400 

kPa

ASTM 

D1267or 25982

Volatility residue (evaporated temperature, 35 °C) Maximum, -38 

°C 

ASTM D1837

Butanes Maximum, 0.05 

m

3

/m3

ASTM D2163

Butenes Maximum, 0.02 

m

3

/m3

ASTM D2163

Pentenes and heavier Maximum, 0.005 

m

3

/m3

ASTM D2163

Propene Maximum, 0.1 

m

3

/m3

ASTM D2163

Residual matter (residue on evap. of 100) ml oil 

stain observ.)

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.
Page 830 of 995

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.

* * * * *

206. A new §1065.725 is added to subpart H to read as follows:

§1065.725 High-level ethanol-gasoline blends.

For testing ethanol-fueled vehicles, create a high-level ethanol-gasoline blend test fuel as 

follows:

(a) Add ethanol to an E15 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 E15 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 80.1510, or fuel-grade ethanol with no denaturant. Be sure to account 

for the volume of any denaturant when calculating volumetric percentages.

(d) The blended test fuel must have a dry vapor pressure equivalent between 6.0 and 6.5 

when measured using the procedure specified in §1065.710. You may add commercial grade 

butane as needed to meet this specification.

207. Section 1065.750 is amended by revising the introductory text and paragraphs (a)(1),

(a)(2), (a)(3), and (a)(5) 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) * * *
Page 831 of 995

(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.

(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 
Page 832 of 995

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.
Page 833 of 995

(ix) C3H8, CO, CO2, NO, balance purified N2.

(x) C3H8, CH4, CO, CO2, NO, balance purified N2.

(xi) N2O, balance purified air and/or N2 (as applicable).

* * * * *

(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]

208. 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 photo-acoustic 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).

* * * * *

209. Section 1065.845 is amended by redesignating paragraphs (a) and (b) as paragraphs (b) 

and (c), respectively, and adding a new paragraph (a) 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 (such as RFMeOH) after FID 

optimization to subtract those responses from the FID reading. Use the most recently determined 
Page 834 of 995

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:

Table 1 of §1065.665–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

* * * * *

210. 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 1066.665 to determine NMOG.

Subpart K—[Amended]

211. Section 1065.1001 is amended by removing the definition for “Engine” and revising the 

definitions for “C1 equivalent (or basis)”, “Oxygenated fuels”, and “Precision” to read as 

follows:
Page 835 of 995

§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.

* * * * *

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.

* * * * *

212. Section 1065.1005 is amended by revising paragraphs (a) and (f)(2) to read as follows:

§1065.1005 Symbols, abbreviations, acronyms, and units of measure.

* * * * *

(a) Symbols for quantities. This part uses the following symbols and units of measure for 

various quantities:

S

ymbol Quantity Unit Unit symbol

Units in 

terms of SI base 

units



atomic hydrogen to carbon 

ratio mole per mole mol/mol 1
Page 836 of 995

A area square meter m

2 m2

A

0

intercept of least squares 

regression

A

1

slope of least squares 

regression

 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

d Diameter meter m m

D

R

dilution ratio mole per mol 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

f

n

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
Page 837 of 995

K correction factor 1

K

v

calibration coefficient m

4

∙s∙K0.5/k

g

m

4

∙s∙K0.5∙k

g

-1

l length meter m m

 viscosity, dynamic pascal second Pa∙s m

-1

∙kg∙s-1

M molar mass1 gram 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

P

F

penetration fraction

p pressure pascal Pa m

-1

∙kg∙s-2

 mass density kilogram per 

cubic meter kg/m3

kg∙m-3
Page 838 of 995

r ratio of pressures pascal per 

pascal Pa/Pa 1

R

2 coefficient of determination

R

a

average surface roughness micrometer m 10-6 m

R

e

# Reynolds number

R

F

response factor

R

H

relative humidity



non-biased standard 

deviation

S Sutherland constant kelvin K K

S

EE 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

t time second s s



t

time interval, period, 

1/frequency second s s

V volume cubic meter m

3 m3
Page 839 of 995

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

w

c

carbon mass fraction gram per 

gram

g/g 1

x

amount of substance mole 

fraction 2 mole per mole mol/mol 1

x flow-weighted mean 

concentration mole per mole mol/mol 1

y generic variable

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. 

* * * * * 

(f) * * *

(2) This part uses the following molar masses or effective molar masses of chemical 

species:

S

ymbol Quantity

g/mol

(10-

3

·kg·mol-1)

M

air

molar mass of dry air128.96559

M

Ar

molar mass of argon 39.948

M molar mass of carbon 12.0107
Page 840 of 995

C

M

CH3OH

molar mass of methanol 32.04186

M

C2H5OH

molar mass of ethanol 46.06844

M

C2H4O

molar mass of acetaldehyde 44.05256

M

C3H8

molar mass of propane 44.09562

M

C3H7OH

molar mass of propanol 60.09502

M

CO

molar mass of carbon monoxide 28.0101

M

CH4

molar mass of methane 16.0425

M

CO2

molar mass of carbon dioxide 44.0095

M

H

molar mass of atomic hydrogen 1.00794

M

H2

molar mass of molecular hydrogen 2.01588

M

H2O

molar mass of water 18.01528

M

HCHO

molar mass of formaldehyde 30.02598

M

He

molar mass of helium 4.002602
Page 841 of 995

M

N

molar mass of atomic nitrogen 14.0067

M

N2

molar mass of molecular nitrogen 28.0134

M

NH3

molar mass of ammonia 17.03052

M

NMHC

effective C1 molar mass of nonmethane hydrocarbon213.875389

M

NMHCE

effective C1 molar mass of nonmethane hydrocarbon 

equivalent2 13.875389

M

NOx

effective molar mass of oxides of nitrogen346.0055

M

N2O

molar mass of nitrous oxide 44.0128

M

O

molar mass of atomic oxygen 15.9994

M

O2

molar mass of molecular oxygen 31.9988

M

S

molar mass of sulfur 32.065

M

THC

effective C1 molar mass of total hydrocarbon213.875389

M

THCE

effective C1 molar mass of total hydrocarbon 

equivalent2

13.875389

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, 
Page 842 of 995

NO2.

* * * * *

213. Section 1065.1010 is amended by revising paragraphs (a) and (f) to read as follows:

§1065.1010 Reference materials.

* * * * *

(a) ASTM materials. Copies of these materials may be obtained from ASTM 

International, 100 Barr Harbor Dr., P.O. Box C700, West Conshohocken, PA 19428–2959, or by

calling (877) 909–ASTM, or at http://www.astm.org.

(1) ASTM D86–11b, Standard Test Method for Distillation of Petroleum Products at 

Atmospheric Pressure, IBR approved for §§1065.703, 1065.710.

(2) ASTM D93–12, Standard Test Methods for Flash Point by Pensky- Martens Closed 

Cup Tester, IBR approved for §1065.703.

(3) ASTM D445–12, Standard Test Method for Kinematic Viscosity of Transparent and 

Opaque Liquids (and Calculation of Dynamic Viscosity), IBR approved for §1065.703.

(4) ASTM D613–10a, Standard Test Method for Cetane Number of Diesel Fuel Oil, IBR 

approved for §1065.703.

(5) ASTM D910–11, Standard Specification for Aviation Gasolines, IBR approved for 

§1065.701.

(6) ASTM D975–12a, Standard Specification for Diesel Fuel Oils, IBR approved for 

§1065.701.

(7) ASTM D1267–02 (Reapproved 2007), Standard Test Method for Gage Vapor 

Pressure of Liquefied Petroleum (LP) Gases (LP-Gas Method), IBR approved for §1065.720.

(8) ASTM D1319–10, Standard Test Method for Hydrocarbon Types in Liquid Petroleum 

Products by Fluorescent Indicator Adsorption, IBR approved for §1065.710.

(9) ASTM D1655–12, Standard Specification for Aviation Turbine Fuels, IBR approved 

for §1065.701.

(10) ASTM D1837–11, Standard Test Method for Volatility of Liquefied Petroleum (LP) 

Gases, IBR approved for §1065.720.

(11) ASTM D1838–12, Standard Test Method for Copper Strip Corrosion by Liquefied 

Petroleum (LP) Gases, IBR approved for §1065.720.
Page 843 of 995

(12) ASTM D1945–03 (Reapproved 2010), Standard Test Method for Analysis of 

Natural Gas by Gas Chromatography, IBR approved for §1065.715.

(13) ASTM D2158–11, Standard Test Method for Residues in Liquefied Petroleum (LP) 

Gases, IBR approved for §1065.720.

(14) ASTM D2163–07, Standard Test Method for Analysis of Liquefied Petroleum (LP) 

Gases and Propene Concentrates by Gas Chromatography, IBR approved for §1065.720.

(15) ASTM D2598–02 (Reapproved 2007), Standard Practice for Calculation of Certain 

Physical Properties of Liquefied Petroleum (LP) Gases from Compositional Analysis, IBR 

approved for §1065.720.

(16) ASTM D2622–10, Standard Test Method for Sulfur in Petroleum Products by

Wavelength Dispersive X-ray Fluorescence Spectrometry, IBR approved for §§1065.703, 

1065.710.

(17) ASTM D2713–12, Standard Test Method for Dryness of Propane (Valve Freeze 

Method), IBR approved for §1065.720.

(18) ASTM D2784–11, Standard Test Method for Sulfur in Liquefied Petroleum Gases 

(Oxy-Hydrogen Burner or Lamp), IBR approved for §1065.720.

(19) ASTM D2880–03 (Reapproved 2010), Standard Specification for Gas Turbine Fuel 

Oils, IBR approved for §1065.701.

(20) ASTM D2986–95a (Reapproved 1999), Standard Practice for Evaluation of Air 

Assay Media by the Monodisperse DOP (Dioctyl Phthalate) Smoke Test, IBR approved for 

§1065.170.

(21) ASTM D3231–11, Standard Test Method for Phosphorus in Gasoline, IBR approved 

for §1065.710.

(22) ASTM D3237–12, Standard Test Method for Lead in Gasoline By Atomic 

Absorption Spectroscopy, IBR approved for §1065.710.

(23) ASTM D4052–11, Standard Test Method for Density and Relative Density of 

Liquids by Digital Density Meter, IBR approved for§1065.703.

(24) ASTM D4629-12, Standard Test Method for Trace Nitrogen in Liquid Petroleum 

Hydrocarbons by Syringe/Inlet Oxidative Combustion and Chemiluminescence Detection, IBR 

approved for §1065.655.

(25) ASTM D4814–11b, Standard Specification for Automotive Spark-Ignition Engine 

Fuel, IBR approved for §1065.701.
Page 844 of 995

(26) ASTM D4815-09, Standard Test Method for Determination of MTBE, ETBE, 

TAME, DIPE, tertiary-Amyl Alcohol and C1 to C4 Alcohols in Gasoline by Gas 

Chromatography, IBR approved for §1065.710.

(27) 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, IBR approved for §1065.703.

(28) ASTM D5191–12, Standard Test Method for Vapor Pressure of Petroleum Products 

(Mini Method), IBR approved for §1065.710.

(29) ASTM D5291–10, Standard Test Method for Instrumental Determination of Carbon, 

Hydrogen, and Nitrogen in Petroleum Products and Lubricants, IBR approved for §1065.655.

(30) ASTM D5599–00 (Reapproved 2010), Standard Test Method for Determination of 

Oxygenates in Gasoline by Gas Chromatography and Oxygen Selective Flame Ionization 

Detection, IBR approved for §1065.655.

(31) ASTM D5762-12 Standard Test Method for Nitrogen in Petroleum and Petroleum 

Products by Boat-Inlet Chemiluminescence, IBR approved for §1065.655.

(32) ASTM D5797–07, Standard Specification for Fuel Methanol (M70– M85) for 

Automotive Spark-Ignition Engines, IBR approved for §1065.701.

(33) ASTM D5798–11, Standard Specification for Fuel Ethanol (Ed75– Ed85) for 

Automotive Spark-Ignition Engines, IBR approved for §1065.701.

(34) ASTM D6615–11a, Standard Specification for Jet B Wide-Cut Aviation Turbine 

Fuel, IBR approved for §1065.701.

(35) ASTM D6751–12, Standard Specification for Biodiesel Fuel Blend Stock (B100) for 

Middle Distillate Fuels, IBR approved for §1065.701.

(36) ASTM D6985–04a, Standard Specification for Middle Distillate Fuel Oil—Military

Marine Applications, IBR approved for §1065.701.

(37) ASTM F1471–09, Standard Test Method for Air Cleaning Performance of a HighEfficiency Particulate Air Filter System, IBR approved for §1065.1001.

* * * * *

(f) SAE material. Copies of these materials may be obtained from the Society of 

Automotive Engineers International, 400 Commonwealth Dr., Warrendale, PA 15096–0001, or 

by calling (724) 776–4841, or at 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.
Page 845 of 995

(2) SAE J1151, Methane Measurement Using Gas Chromatography, Revised September 

2011, IBR approved for §§1065.267 and 1065.750.

214. A new subpart L is added to read as follows:

Subpart L—Methods for Unregulated and Special Pollutants

Sec.

1065.1101 Applicability.

1065.1103 General provisions for SVOC measurement.

SEMI-VOLATILE ORGANIC COMPOUNDS

1065.1105 Sampling system design.

1065.1107 Sample media and sample system preparation; sampler assembly.

1065.1109 Post-test sampler disassembly and sample extraction.

1065.1111 Sample analysis.

§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 primarily 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 COUMPOUNDS

§1065.1103 General provisions for SVOC measurement.

The provisions of §§1065.1103 through 1065.1111 specify procedures for the 

measurement of semi-volatile organic compounds (SVOC) along with PM. The provisions of 

these sections specify how to collect a sample of the SVOCs during exhaust testing procedures, 

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 
Page 846 of 995

measured. For example, the method used to measure polynuclear aromatic hydrocarbons (PAHs) 

will differ slightly from the method used to measure dioxins.

(a) Laboratory cleanliness is especially important throughout the course of SVOC testing. 

Thoroughly clean all sample train components and glassware before testing to avoid sample 

contamination.

(b) Throughout the course of your testing we recommend that media blanks be analyzed 

for each batch of media (sorbent, filters, etc.) that is prepared for testing. Blank sorbent modules 

with inlet and outlet covered (i.e., field blanks) should periodically accompany the test sample 

train throughout the course of a test, including the sample train and sorbent module disassembly, 

sample packaging, and storage. Use good engineering judgment to determine the frequency of 

field blanks. During testing, the field blank sample train should reside in close proximity to the 

sampler.

(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 nPAH), 

perform these procedures in the dark or with ultraviolet filters installed over the lights.

(e) Follow standard analytic chemistry methods for aspects of the analysis not specified.

(f) The following definitions and abbreviations apply for SVOC measurements:

(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 cross linked polystyrene copolymer resin adsorbent 

known commercially as Amberlite® XAD®-2, or an equivalent adsorbent.

(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 and have a boiling point between 240°C and 400°C. SVOCs include dioxin, quinone, 

and nitro-PAH compounds. They may be a natural byproduct of combustion or created post 

combustion. Note that SVOCs may be detected as hydrocarbons and/or PM using the 

measurement procedures specified in this part; in other words, some fraction of measured mass 

of hydrocarbons and/or PM may be SVOCs.

(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.
Page 847 of 995

(7) Isotopically labeled means relating to a compound in which either all of 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 minimize the amount of SVOCs lost to the system. To the extent 

practical, adjust sampling times based on the rate of emission of target analytes from the engine 

to obtain analyte concentrations above the limit of detection. In some instances you may need to 

run repeat test cycles without replacing the sample media or disassembly of 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. All joints in the hot zone of the system should be 

sealed with gaskets made of nonreactive material similar to that of the sample train components. 

Teflon gaskets may be used in the cold zone. We recommend keeping the sampling system 

length as short as possible by locating all components as close to probes as practical to minimize 

the surface exposed to the 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 

that 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) Sample probe. Use a sample probe similar to the PM sample probe specified in 

subpart B of this part. We recommend that you heat the sample probe with a set point no higher 

the 200 °C. Note that heat from the engine exhaust may cause the probe temperature to exceed 

200°C at some points during the test.

(2) Filter holder. Use a PM filter holder similar to type of 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 the use of 110 mm filter for the testing of engines that utilize exhaust 

after treatment for removal of PM and 293 mm filters for engines that do not. You may heat the 

filter holder, but we recommend that your set point does not exceed 200°C. 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 SVOCs on the filter. In this method SVOCs that pass 

through the filter will be collected on the downstream sorbent module. 

(3) Cooling coil. Use good engineering judgment to design a cooling coil (to be used 

with the water bath described in paragraph (e) of this section) that will drop the sample 
Page 848 of 995

temperature to approximately 5°C. Note that downstream of the cooling coil, the sample will be 

a mixture of a vapor phase hydrocarbons in CO2 and air and a primarily aqueous liquid phase. 

(4) Sorbent and sorbent module. 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 polyurethane (PUF) plugs at either end of the module.

(5) Condensate trap/drain. 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 recommended targeting an average sample flow rate of 70 l/min 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; sampler assembly.

This section describes the types of sample media to be used as well as 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 some of the SVOCs, and a second to capture SVOCs 

that remain in the gas phase. Use the following sample media for capture of PM and gas phase 

SVOCs:

(1) For capture of PM, use pure quartz filters that do not contain any binder. Size the 

filter diameter to account for the expected PM emission rate, sample flow rate, and number of 

repeat tests to minimize filter change intervals. Note that when repeating test cycles to increase 

sample mass, you may replace the filter without replacing the sorbent or otherwise disassembling 

the batch sampler. In those cases include all filters in the extraction.

(2) For capture of 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/XAD-2 as needed. If the media is not to be used immediately after cleaning, store 

it in containers protected from light and ambient air.
Page 849 of 995

(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 via a series of Soxhlet extractions: 8 h with water, 22 h 

with methanol, 22 h 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 

followed by three rinses with toluene. Prepare pre-cleaned aluminum foil for capping the probe 

inlet of the sampler after the sample train has been assembled.

(c) Sorbent spiking. Use good engineering judgment to verify the extent to which your 

extraction methods recover SVOCs absorbed to the sample media. We recommend spiking the 

XAD-2 resin with a surrogate standard prior to 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 and then add the 

remaining 20 g of the XAD-2 resin to the module followed by the top PUF plug.

(4) Cover the inlet and outlet of the sorbent module with pre-cleaned aluminum foil.

(d) Sample train assembly. Upon completion of the sample media and sampler 

preparation, assemble the condensate trap, cooling coil, filter holder with filter, and sample probe 

to the sorbent module and lower assembly into the reservoir. Cover the probe inlet with precleaned aluminum foil.

§1065.1109 Post-test sampler disassembly and sample extraction.

This section describes the process for sample train disassembly, sample train rinsing, 

sample extraction, and sample clean-up.

(a) Sample train disassembly. Disassemble the sample train in a clean environment upon 

completion of testing. Prepare to extract the SVOCs as follows:

(1) Remove the PM filter, PUF, and all of the XAD-2 from the sample train and place 

them into a Soxhlet extraction thimble. If the sample media are to be stored, store them at ≤ 37 

°C.
Page 850 of 995

(2) Rinse sample train wetted surfaces upstream of the condensate trap with acetone 

followed by toluene (or a comparable solvent system), ensuring that all of the solvent that 

remains in liquid phase is collected (note that a fraction of the acetone and toluene will likely be 

lost via evaporation during mixing.) Rinse with solvent volumes that are sufficient to cover the 

all of the surfaces exposed to 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 

sample train 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 bottles purchased pre-cleaned). 

(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 sepratory

funnel or equivalent. Add the toluene from this aqueous extraction to the toluene rinsate fraction 

mentioned 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. Care should be taken when concentrating via rotary evaporation to avoid loss of low 

molecular weight analytes.

(b) Sample extraction. Extract the SVOCs from the sorbent using Soxhlet extraction 

extraction as described in this paragraph (b). To accommodate the Soxhlet extractions of all 

SVOCs from a single sample, two 16 hour extractions are required. This will reduce the 

possibility of loss of low molecular weight SVOCs and promote water removal. We recommend 

performing the first extraction with acetone/hexane and the second using toluene (or an 

equivalent solvent system).

(1) We recommend equipping the Soxhlet extractor with a Dean-Stark trap to facilitate 

the removal of residual water from the sample train 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 hr Soxhlet extraction with methylene chloride at a cycling rate of 3 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 then add approximately half of the XAD-2. The 

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 extraction standard delivery. We recommend 

using multiple isotopically labeled extraction standards that cover the range of target analytes. 

Generally this 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 
Page 851 of 995

XAD-2 to the thimble followed by the remaining PUF plug. Then place the thimble into the 

extractor.

(3) For the initial extraction, combine the concentrated acetone rinses (from the sample 

train 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 so that the extraction 

cycles at a rate of 3.0±0.5 cycles per hour. Drain the water from the Dean-Stark trap as it 

accrues by opening the stopcock on the trap. Discard this water unless it is to be analyzed. In 

most cases, any water present will be removed within approximately 2 hours of the start of the 

extraction.

(4) Upon completion of 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 three-ball 

Snyder column with venting dimples and graduated collection tube. The use of this concentrator 

will minimize evaporative loss of lower molecular weight analytes.

(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 

concentration apparatus.

(iii) Repeat paragraphs (i) and (ii) of this section 3 times or as necessary, to remove all of 

the residual solvent from the extractor round bottom flask, concentrating the final rinse to 4 ±0.5 

mL.

(5) For the second extraction, combine the toluene rinses (from the sample train 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 this paragraph (a) of this section, you may need to 

concentrate the rinse prior to addition to the extraction apparatus if the rinse solvent volume is 

too large. Allow the sample to reflux for 16 hours with the rheostat adjusted so that the 

extraction cycles at a rate of 3.0 ±0.5 cycles per hour. Although little or no water should be 

present during this stage, check the Dean-Stark trap during the first 2 hours of the extraction.

(6) Upon completion of the second extraction, remove the solvent and concentrate it to 4 

±0.5 mL as described in paragraph (4) of this section. Using hexane from paragraph (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 (6) of this section. Divide the extract into a number of 

fractions based on the number of analyses to be performed. 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 unwanted SVOCs (that is, those SVOCs which you are not analyzing for) and solids 

from the sample extract before analysis. This process, which is known as “sample clean up, 
Page 852 of 995

reduces the potential for interference or co-elution of peaks during analytical analysis. Before 

proceeding with the sample clean up, spike the extract with an alternate standard that contains a 

known mass of isotopically labeled compounds that are identical (with the exception of the 

labeling) to the target analytes. The number of compounds that make up the standard will be 

determined by the category of the target analyte compounds (such as PAHs or dioxin). For 

example, PAHs require the use of 4 compounds in the alternate standard to cover the 4 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 to a volume of 

about 1 mL using a Kuderna-Danish concentrator. Since there are several column 

chromatographic cleanup options available, use good engineering judgment to select one 

appropriate for your target analytes. Note that these clean-up techniques generally remove 

compounds based on their polarity. The clean up procedures given in paragraphs (c)(1) and (2) 

below are examples of clean-up techniques for PAHs and nitropolynuclear aromatic 

hydrocarbons (nPAHs).

(1) PAH clean up. The following method is appropriate for cleaning up 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 followed by the addition of 10 grams 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. Since variations among batches of silica gel may affect the 

elution volume of the various PAH, the volume of solvent required to completely elute all of the 

PAH must be verified by the analyst. The weight of the silica gel can then be adjusted 

accordingly.

(ii) Elute the column with 40 mL of hexane. The rate for all elutions should be about 2 

mL/min and you may use dry air or N2 to maintain the headspace slightly above atmospheric 

pressure to increase the elution rate. Discard the eluate just prior to exposure of the sodium 

sulfate layer to the air or N2, transfer the 1 mL sample extract onto the column using two 

additional 2 mL rinses of hexane to complete the transfer. Just prior to exposure of the sodium 

sulfate layer to the air or N2, 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 that you 

do not evaporate all of the solvent from the extract during the concentration process. Transfer to 

a small sample vial using a hexane rinse and concentrate to 100 μL using a stream of nitrogen, 

gentle enough to not violently disturb the solvent. Store the extracts in a refrigerator at 4 °C or 

lower away from light until analysis.

(2) nPAH clean up. The following procedure, that was 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:
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(i) Condition an aminopropyl solid phase extraction (SPE) cartridge by eluting it with 20 

mL of 20 volume % methylene chloride in hexane before use. Transfer the extract quantitatively

to the SPE cartridge with at least two methylene chloride rinsings. 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. Then reduce the extract to 0.5 ml in hexane and 

subject the extract to normal-phase liquid chromatography using pre-prepared a 9.6 mm X 25 cm 

semi-preparative Chromegabond®amino/cyano column, 5 μm particle size to isolate the nPAH 

fraction. The mobile phase is 20 volume % methylene chloride in hexane at a constant flow rate 

of 5 ml/min. Prior to each injection, the column should be back flashed with 60 ml of methylene 

chloride and then conditioned with 200 ml of 20 volume % methylene chloride in hexane. 

Collect the effluent and concentrate to about 2 mL using the Kuderna-Danish concentrator or a 

rotary evaporator. Transfer to a minivial using a hexane rinse and concentrate to 100 μL using a 

gentle stream of nitrogen. Store the extracts at 4°C or lower away from light until analysis.

§1065.1111 Sample analysis.

This subpart does not specify chromatographic or analytical methods to analyze extracts, 

because the selection of such methods is highly dependent on the nature of the target analytes. 

However, we recommend that prior to whichever sample analysis you choose, you spike the 

extract with an injection standard that contains a known mass of an isotopically labeled 

compound that is identical (with the exception of the labeling) to one of the target analytes. This 

injection standard is used to monitor the efficiency of the analytical process by verifying the 

volume of sample injected for analysis.

1. Part 1066 is revised to read as follows:

Part 1066—Vehicle-Testing Procedures

Subpart A—Applicability and General Provisions 

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.
Page 854 of 995

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.

1065.122 Data updating, recording, and control for measurement instruments.

1066.130 Measurement instrument calibrations and verifications.

1066.137 Linearity verification.

1066.140 Diluted exhaust flow calibration.

1066.145 Engine fluids, test fuels, analytical gases, and other calibration standards.

1066.150 Analyzer interference and quench verification limit.

Subpart C—Dynamometer Specifications

1066.201 Dynamometer overview.

1066.210 Dynamometers.

1066.215 Summary of verification and calibration 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 calibration.
Page 855 of 995

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.

1066.280 Daily dynamometer readiness verification.

1066.290 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.

1066.320 Dynamometer road-load setting.

Subpart E—Preparing Vehicles and Running an Exhaust Emission Test

1066.401 Overview.

1066.407 Vehicle preparation and preconditioning.

1066.410 Dynamometer test procedure.

1066.420 Vehicle operation.

1066.425 Test preparation.

1066.430 Performing emission tests.

Subpart F—Hybrids and Electric Vehicles

1066.501 Overview.
Page 856 of 995

Subpart G—Calculations

1066.601 Overview.

1066.610 Mass-based and molar-based exhaust emission calculations.

1066.620 Dilution air background correction.

1066.630 NOx intake-air humidity correction.

1066.640 Removed water correction.

1066.650 Flow meter calibration calculations.

1066.652 PDP, SSV, and CFV flow rate calculations.

1066.665 NMOG determination.

1066.695 Data requirements.

Subpart H—Cold-Temperature Test Procedures

1066.701 Applicability and general provisions.

Subpart I—Exhaust Emission Test Procedures for Motor Vehicles

1066.801 Applicability and general provisions.

1066.810 Road load power, test weight, and inertia weight class determination.

1066.814 Vehicle preparation.

1066.820 Exhaust emission test procedures for FTP emissions.

1066.822 Composite calculations for FTP exhaust emissions.

1066.830 Supplemental Federal Test Procedures; overview.

1066.831 Exhaust emission test procedures for agressive driving.

1066.832 Exhaust emission test procedure for SC03 emissions.

1066.835 AC17 Air conditioning efficiency test procedure.
Page 857 of 995

1066.839 Highway fuel economy test procedure.

1066.840 Fuel storage system leak test procedure.

Subpart J—[Reserved]

Subpart K—Definitions and Other Reference Material

1066.1001 Definitions.

1066.1005 Symbols, abbreviations, acronyms, and units of measure.

1066.1010 Reference materials.

Authority: 42 U.S.C. 7401-7671q.

Subpart A—Applicability and General Provisions 

§1066.1 Applicability.

(a) This part describes the 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 highway vehicles (light-duty and heavy-duty) that are 

subject to chassis testing for exhaust emissions under 40 CFR part 86. 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 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. 
Page 858 of 995

(d) 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 standardsetting parts for light-duty vehicles. For vehicles subject to 40 CFR part 86, subpart S, 

references to the standard-setting part include subpart I of this part.

(e) 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.

(f) 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.

§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.
Page 859 of 995

§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 N2O or CH4 emission standards.

(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?

(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) [Reserved]

(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 standardsetting 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:
Page 860 of 995

Table 1 of §1066.5—Description of Part 1066 subparts.

This 

subpart

Describes these specifications or procedures

Subpar

t A

Applicability and general provisions.

Subpar

t B

Equipment for testing.

Subpar

t C

Dynamometer specifications.

Subpar

t D

Coastdowns for testing.

Subpar

t E

How to prepare your vehicle and run an emission test.

Subpar

t F

How to test hybrid vehicles.

Subpar

t G

Test procedure calculations.

Subpar

t H

Cold temperature testing.

Subpar

t I

Exhaust emission test procedures for motor vehicles.

Subpar

t J

Reserved.

Subpar

t K

Definitions and reference material.
Page 861 of 995

§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 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) In the standard-setting part, we set 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.
Page 862 of 995

(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 mass, 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 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 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 distancebased emission value to compare to the standard.

(2) Constituent determination. Determine the total mass of each constituent over a test 

interval by selecting from the following methods:

(i) Continuous sampling. In continuous sampling, measure the 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 HC, CO, and NOx 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 
Page 863 of 995

(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 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 the regulation 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 any

system of units. Where the equations depend on the use of specific units, these units are 

identified.

(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.

(5) For ideal gases, 1 μmol/mol = 1 ppm.

(6) For ideal gases, 10 mmol/mol = 1 %.
Page 864 of 995

(c) Temperauture. 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. Flowweighted 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 flowweighted mean concentration, because the CVS system itself flow-weights the bag 

concentration.

§1066.25 Recordkeeping.
Page 865 of 995

The procedures in this part include various requirements to record data or other 

information. Refer to the standard-setting part and §1066.695 regarding recordkeeping 

requirements. You must promptly send us organized, written records in English if we ask for 

them. We may review them at any time.
Page 866 of 995

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. This section addresses emission sampling and analytical equipment, 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 instrument; 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 determinations as described in 

§1066.665.

(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 and/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.
Page 867 of 995

(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 accurately represent the humidity of 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 rear-mounted 

engines, or it does not provide adequate cooling to properly represent in-use operation, you may 

ask us to approve increasing the fan’s 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 FTP and LA-92 test cycles, the allowable cooling fan configurations are described 

in paragraphs (c)(2) and (4) of this section.

(ii) For the US06 test cycle, the allowable cooling fan configurations are described in 

paragraphs (c)(2) and (5) of this section. The cooling fan configuration in paragraph (c)(4) of 

this section is also allowable with advance approval.

(iii) For SC03 and AC17 test cycles, the allowable cooling fan configuration is described 

in paragraph (c)(3) of this section.

(iv) For the HFET test cycle, the allowable cooling fan configurations are described in 

paragraphs (c)(2) and (4) 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 (2.2 to 13.4 

m/s), 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 speed corresponding to vehicle speeds of 20 and 40 

mph using an instrument that has an accuracy of ±2 % of the measured air flow speed.
Page 868 of 995

(ii) For fans with rectangular outlets, divide the fan outlet into the as shown in Figure 1 of 

this section. As denoted by the “+” in the figure, measure flow from the center of each section; 

however do not measure the flow from the center section.

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 denoted by the “+” in the figure, measure flow on the radial 

centerline of each section (at 22.5°) at a radius of two-thirds of the total radius.

Figure 2 of §1066.105—Circular fan outlet grid.

(iv) Verify that the fan air flow velocity vector perpendicular to the axial flow velocity 

vector is less than 15% of the mean velocity measured at fan speeds corresponding to vehicle 

speeds of 20 and 40 mph.

(v) Verify that the uniformity of the fan axial flow tolerance is within ±4.0 mph at fan 

speeds corresponding to 20 mph and within ±8.0 mph at fan speeds corresponding to 40 mph. 

For example, at 20 mph, flow at all axial locations denoted by the “+” across the discharge 

nozzle must be between 16 and 24 mph. Measure the fan axial air flow velocity 60 cm from the 

nozzle outlet at each point of the discharge area grid.

(3) For SC03 and AC17 testing, use a road-speed modulated fan with a minimum air flow 

nozzle 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. When meeting the minimum 

discharge area requirements, the flow volume would vary from 0 m3/s at 0 mph to approximately
Page 869 of 995

450 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 that the fan air flow velocity vector perpendicular to the axial flow velocity

vector is less than 10 % of the mean velocity measured at fan speeds corresponding to vehicle 

speeds between 20 and 40 mph.

(iii) Verify that the uniformity of fan axial flow tolerance is 20 % of the fan speed 

corresponding to vehicle speeds of 20 and 40 mph. For example, at 20 mph, flow at all axial 

locations across the discharge nozzle must be between 16 and 24 mph. Measure the fan axial air 

flow velocity 60 cm from the nozzle outlet at each point of the discharge area grid.

(iv) The instrument used to verify the air velocity must have an accuracy of ±2 % of the 

measured air flow speed.

(v) 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 m

3

/s for all additional fans.

(4) You may use a fixed-speed fan with a maximum capacity up to 2.50 m3/s for FTP, 

LA-92, and HFET testing. 

(5) You may use a fixed-speed fan with a maximum capacity up to 7.10 m3/s for US06 

testing.

(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 (2.2 to 13.4 m/s), 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 50 

mph, and a minimum speed profile across the duct, in the free stream flow, 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 two broad categories—dynamometers (described further 

in subpart C of this part) and emission-sampling hardware. Other related sections in this subpart 

identify measurement instruments (§1066.120), describe how to evaluate the performance of 

these instruments (§§1066.130 and 1066.137), describe how to calibrate a CVS (§1066.140), 

specify engine fluids and analytical gases (§1066.145), and specify requirements for analyzer 

interference and quench verification (§1066.150). 

(b) The following equipment specifications apply for testing under this part:
Page 870 of 995

(1) Tailpipe connections. Connect a vehicle’s exhaust system to any dilution stage as 

follows:

(i) Minimize laboratory exhaust tubing lengths. You may use a total length of laboratory

tubing up to 4 m, without needing to heat or insulate the tubing. However, you may use a total 

length of laboratory tubing up to 10 m if you insulate and/or heat the tubing to minimize the 

temperature difference between the exhaust gas and the tubing wall over the course of the 

emission test. The laboratory exhaust tubing starts at the end of the vehicle’s tailpipe. The 

laboratory exhaust tubing ends at the first sample point or the point of first dilution. You may

use flexible laboratory exhaust tubing at any location in the laboratory exhaust system, although 

we recommend that you limit the amount of flexible tubing to the extent practicable. For 

multiple-tailpipe configurations where the tailpipes combine into 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 smooth-walled.) For 

measurements involving PM, tubing materials must also be electrically conductive. Stainless 

steel is an acceptable material for any measurements. 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, you may configure the exhaust 

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 combined exhaust stream, where 

Re# is based on the inside diameter of the combined flow at the first sampling point. Re# is 

defined in 40 CFR 1065.640.

(2) Provisions from 40 CFR part 1065. Use equipment specifications in 40 CFR 

1065.140 through 40 CFR 1065.190, except as follows:
Page 871 of 995

(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 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 test interval duration 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 sample train used during the emission test. For this background 

sampling, the dilution tunnel blower must be turned on, the vehicle must be disconnected from 

the exhaust transfer tube, and the exhaust transfer tube must be capped.

(C) The duration of your background sample does not need to be the same as the test 

cycle in which you are applying the background correction, provided it is not inconsistent with 

the use of good engineering judgment.

(D) Your background correction may not exceed 5 μg or 5 % of the net PM mass 

expected at the standard, whichever allowance 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 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 determined in Eq. 1066.620-2 or 1066.620-3, 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. 1066.620-4. The maximum dilution factor limit of 20:1 does not apply for plug-in hybrid 

electric vehicles (PHEVs) and hybrid electric vehicles (HEVs), since the dilution factor is 

infinite when the engine is off; however we strongly recommend that you stay under the 

maximum dilution factor limit when the engine is running. For partial-flow sampling systems, 

determine dilution factor using Eq. 1066.620-3. When determining dilution factor for PM 

samples utilizing secondary dilution air, multiply the dilution factor by the dilution ratio of 

secondary dilution air to primary diluted exhaust.
Page 872 of 995

(iv) In addition to the allowances in 40 CFR 1065.140(c)(6) you may also 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, provided they do not affect your ability to demonstrate compliance with the standard:

(A) You may use accordion-style or smooth-walled flexible tubing in the dilution tunnel 

upstream of flow or gaseous emission measurement locations.

(B) You may use smooth-walled electrically conductive flexible tubing in the dilution 

tunnel upstream of where PM emission measurements are made.

(C) Materials for inside surfaces are limited to 300 series stainless steel and polymerbased materials.

(D) Use good engineering judgment to ensure that the materials you choose do not cause 

or contribute to significant loss of PM from your sample.

(vi) Paragraph (b)(1)(vi) of this section applies instead of 40 CFR 1065.145(b).

(c) The following table summarizes the requirements of paragraph (b)(2) of this section:
Page 873 of 995

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:

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 §1066.122 apply instead of 40 CFR 1065.202.

(b) The provisions of 40 CFR 1065.210 and 1065.295 do not apply.

§1066.122 Data updating, recording, and control for measurement instruments.

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.
Page 874 of 995

(a)(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. Values may be recorded at the same frequency. They may also be recorded as means 

of the values, provided the frequency of the mean values meets the minimum recording 

frequency. All values read must be either recorded or used to calculate the 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:

Table 1 of §1066.122–Data recording and control minimum frequencies

Applicabl

e Section Measured Values

Minim

um Command 

and Control 

Frequency

Minim

um Recording 

Frequencya

§1066.31

0

§1066.32

0

Vehicle speed — 10 Hz

§1066.43

0

Continuous concentrations of raw or 

dilute analyzers — 1 Hz

§1066.43

0

§1066.50

1

Power analyzerb — 1 Hz

§1066.43 Bag concentrations of raw or dilute — 1 mean 

value per test 
Page 875 of 995

0 analyzers interval

40 CFR 

1065.545

§1066.43

0

Diluted exhaust flow rate from a CVS 

with a heat exchanger upstream of the flow 

measurement

— 1 Hz

40 CFR 

1065.545

§1066.43

0

Diluted exhaust flow rate from a CVS 

without a heat exchanger upstream of the flow 

measurement

N/A 1 Hz 

means

40 CFR 

1065.545

§1066.43

0

Dilution air flow if actively controlled 

(for example, a partial-flow PM sampling 

system)

5 Hz 1 Hz 

means

40 CFR 

1065.545

§1066.43

0

Sample flow from a CVS that has a 

heat exchanger 1 Hz 1 Hz

40 CFR 

1065.545

§1066.43

0

Sample flow from a CVS that does not 

have a heat exchanger 5 Hz 1 Hz means

§1066.42

5

Ambient temperature — 1 Hz

§1066.42

5

Ambient humidity — 1 Hz

§1066.42

5

Heated sample system temperatures, 

including PM filter face — 1 Hz

a

1 Hz means are data reported from the instrument at a higher frequency, but recorded as a series 

of mean values at a rate of 1 Hz.

b

For power analyzers’ sampling frequency, follow SAE J1711 (incorporated by reference in 
Page 876 of 995

§1066.1010).

§1066.130 Measurement instrument calibrations and verifications.

The measurement instrument calibration and verification requirements in 40 CFR 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. Section 1066.133 specifies additional 

calibration and verification provisions that apply specifically for chassis testing.

(b) The linearity verification provisions of 40 CFR 1065.307 do not apply for engine 

speed, torque, fuel rate, or intake air flow. Section 1066.137 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.

(e) If you are measuring flow volumetrically (rather than by molar), 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 have to be 

performed. Perform other required or recommended calibration and verifications as described in 

40 CFR 1065.303, with the exceptions noted in this section. Table 1 follows:
Page 877 of 995

Table 1 of §1066.130–Summary of required calibration and verifications.

Type of calibration 

or verification Minimum frequencya

40 CFR 1065.303: 

Flow rates

This calibration does not apply for testing under this part; see §1066.133 

for alternative provisions.

40 CFR 1065.307: 

Linearity verification

The linearity calibrations 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 §1066.137 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 
Page 878 of 995

manufacturer’s instructions and good engineering judgment.

§1066.137 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 calibration and 

verifications as described in 40 CFR 1065.307, with the exceptions noted in this section. 

(a) For testing under this subpart, linearity verification under 40 CFR part 1065 is not 

required for speed, torque, fuel flow rate, or intake air flow.

(b) 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 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 single calibration factor 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 drift check and drift correct your 

emission data according to 40 CFR 1065.672.

(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 constant value 
Page 879 of 995

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 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.

(2) Barometric pressure.

(3) CVS inlet gage pressure or absolute pressure transducer.

(4) 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 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. 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.
Page 880 of 995

(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, a set of critical flow venturis, or an ultrasonic flow 

meter. Use a reference 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 

calculatingQref



.

(ii) The mean temperature at the PDP inlet, Tin .

(iii) The mean static absolute pressure at the PDP inlet, in p .
Page 881 of 995

(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 (e)(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 §1066.650(a).

(10) Repeat the steps in paragraphs (e)(6) through (9) of this section for each speed at 

which you operate the PDP.

(11) Use the equations in §1066.652(a) to determine the PDP flow equation for emission 

testing.

(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.
Page 882 of 995

(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, such as reference meter pressures and temperatures, for 

calculatingQref



.

(ii) The mean temperature at the venturi inlet, Tin .

(iii) The mean static absolute pressure at the venturi inlet, in p .

(iv) 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 a functional form of Cd versus Re#by using the collected data and the 

equations in §1066.650(b).

(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.

(12) Use the equations in §1066.652(b) to determine SSV flow during a test.

(h) CFV calibration. The calibration procedure described in this paragraph (h) 

establishes the value of the calibration coefficient at measured values of pressure, temperature 

and air flow.

Calibrate a critical-flow venturi (CFV) to verify its calibration coefficient, Kv, at the 

lowest expected static differential pressure between the CFV inlet and outlet. Calibrate a CFV 

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 CFV are less than 

0.3 % of the total flow at the highest restriction.

(3) Start the blower downstream of the CFV.
Page 883 of 995

(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 (f)(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 §1066.650.

(10) Use Kv to determine CFV flow during an emission test. Do not use the CFV below 

the lowest allowed r, as determined in §1066.650.

(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 §1066.650(c). 

Refer to §1065.652(c) for instructions on calculating flow rates for this option.
Page 884 of 995

(ii) Calibrate each CFV according to this section and §1066.650. Refer to §1066.652 for 

instructions on calculating flow rates for this option.

(i) Ultrasonic flow meter calibration. [Reserved]

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 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

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
Page 885 of 995

§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.

(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 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
Page 886 of 995

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 international standards organization 

to be sufficient to demonstrate NIST-traceability. The force-measurement 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 dynamometers 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.

(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 roadload 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.
Page 887 of 995

(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. For vehicles at or below 14,000 pounds GVWR, 

determine the vehicle’s mass based on equivalent test weight (ETW) as specified in §1066.810

and set dynamometer inertia simulation as specified in §1066.410(h). For vehicles above 14,000 

pounds GVWR, determine the vehicle’s mass based on the test weight, taking into account the 

effect of rotating axles, as specified in §1066.310(b)(7) and dividing the weight by the 

acceleration due to gravity as specified in 40 CFR 1065.630, consistent with good engineering 

judgment. 

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. Dynamometers that do not fully meet this 

specification may be used consistent with good engineering judgment. For example, slightly

higher errors may be permissible during highly transient operation for vehicles above 8,500

pounds GVWR.
Page 888 of 995

(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 and calibration 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:
Page 889 of 995

Table 1 of §1066.215–Summary of required dynamometer calibrations and 

verifications.

Type of calibration or 

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 §1066.280.

§1066.260: Parasitic 

friction compensation evaluation

Upon initial installation, after major maintenance, and upon 

failure of a verification in §1066.270 or §1066.280.

§1066.265: Acceleration 

and deceleration verification Upon initial installation and after major maintenance.

§1066.270: Unloaded Upon initial installation, within 7 days of testing, and after 
Page 890 of 995

coastdown verification major maintenance.

§1066.280 

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.

(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
Page 891 of 995

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.

(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, iy . 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.
Page 892 of 995

(12) Use the arithmetic means, iy , 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

Measu

rement system

Qu

antity

Linearity criteria

| 

ymin(a1-1)+a0 |

a

1

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.

(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 
Page 893 of 995

using a nominally permanent 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®.

(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. 
Page 894 of 995

(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 yy

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.
Page 895 of 995

(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. 

(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 verify the dynamometer 

speed at any devices used to display or record vehicle speed (for example 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
Page 896 of 995

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

(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
Page 897 of 995

(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 280.

§1066.245 Response time verification.

(a) Overview. This section describes how to verify the dynamometer’s response time to a 

tractive effort force step change.

(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 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 (for 

example 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 
Page 898 of 995

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. 

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 assembly 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, and 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.
Page 899 of 995

(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:

b

final initial

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.

vinitial = 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

vinitial = 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
Page 900 of 995

(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 arithmetic mean value, bI , from the ten acceleration and 

deceleration interval base inertia values for each of the three acceleration/deceleration rates. 

Then determine the base inertia arithmetic mean value, bI , from the three 

acceleration/deceleration rate mean base inertia values. Calculate base inertia mean values as 

described in 40 CFR 1065.602(b)

(8) Calculate the inertia error for the final mean base inertia value from paragraph (c)(7) 

of this section. Use Eq. 1066.250-2, substituting the final mean base inertia 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 mean base inertia error determined under paragraph (c)(8) of this section may not 

exceed ±0.20 %. 

§1066.255 Parasitic loss verification.
Page 901 of 995

(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 road-load 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 §1066.280. 

(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 updates 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 §1066.280. Note that this 

procedure relies on proper calibration 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.

(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.
Page 902 of 995

(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 torque control 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
Page 903 of 995

(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 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 calibration 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.
Page 904 of 995

(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

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.
Page 905 of 995

(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:

F Ib   a

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
Page 906 of 995

a = 1 mph/s = 1.4667 ft/s2

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 roadload 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 
Page 907 of 995

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

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, expressed in ft/s and rounded to four 

significant figures.

vfinal = the speed at the end of the coastdown interval, rounded to four significant figures.

t = coastdown time for each speed 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
Page 908 of 995

(5) Calculate the target value of coastdown force, Fref, based on the applicable 

dynamometer parameters for each speed and inertia setting.

(6) Compare the mean value of the coastdown force measured for each speed 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

Fact = 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:

(i) For vehicles at or below 20,000 pounds GVWR, calculate Ferrormax from the following 

formula:

Ferrormax (%) = (2.2 lbf/Fref)·100

Eq. 1066.270-3

Example:

Fref = 192 lbf

Ferrormax (%) = (2.2/192)·100 = 1.14%

(ii) For vehicles above 20,000 pounds GVWR, the maximum allowable error, Ferrormax, 

for all speed and inertia settings is ±1.0 % or ±39.2 N, whichever is greater.
Page 909 of 995

(e) 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.

§1066.280 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) 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.
Page 910 of 995

§1066.290 Driver’s aid.

Use good engineering judgment to provide a driver’s aid that facilitates compliance with 

the requirements of §1066.430. 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.
Page 911 of 995

(a) Determine 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:

(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, then the road grade as a function of distance along the 

length of the test surface must be incorporated into the analysis. To calculate the force due to 

grade use Section 11.5 of SAE J2263.

(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 a maximum speed as described in this paragraph (b)(2) and a minimum speed of 15 mph.

(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 location of that 

anemometer.

(iv) Mount the anemometer at a height that is within 6 inches of half the test vehicle’s 

maximum height.
Page 912 of 995

(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 70 mph down to 15 mph) in that 

direction. Eliminate runs outside this range. After 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 70 mph. Establish the height or altitude 

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, for values of i ≥ 1 

using the following equation:

i i 1

i e

v v F M

t

    



Eq. 1066.310-1
Page 913 of 995

Where:

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 height or altitude 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:

adj

D

2 D

C A







Eq. 1066.310-3

Where:

ρ = air density at reference conditions = 1.17 kg/m3.

adj

B

98.21

293

T

D D

p

   

          

Eq. 1066.310-4
Page 914 of 995

T = average ambient absolute temperature during testing, in K.

B

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

§1066.320 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 subpart I of this part or 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.
Page 915 of 995

(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 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 use the calculations in 40 CFR part 1065, subpart G, or 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.

§1066.407 Vehicle preparation and preconditioning.

Prepare the vehicle for testing (including measurement of evaporative and refueling 

emissions, as required) 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.
Page 916 of 995

(b) Place the vehicle onto the dynamometer without starting the engine (for cold-start test 

cycles) or drive the vehicle onto 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) or (d) that is placed 

within 90 cm of the front of the vehicle and ensure that the engine compartment cover is closed:

(1) For SC03 and AC17 testing, use a road-speed modulated fan meeting the 

requirements of §1066.105(c)(3). Position the discharge nozzle such that its lowest point is not 

more than 16 cm above the floor of the test cell.

(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 meeting the requirements of §1066.105(c)(4) or (c)(5) as 

specified in the following table, with the engine compartment cover open:

Table 1 of §1066.410–Fixed-speed fan capacity and position specifications.

Test cycle Maximum fan capacity Approximate distance 

from the front of the vehicle

FTP Up to 2.50 m3/s 0 to 30 cm

US06 2.50 m3/s to 7.10 m3/s 0 to 60 cm

LA-92 Up to 2.50 m3/s 0 to 30 cm

HFET Up to 2.50 m3/s 0 to 30 cm

(c) Record the vehicle’s speed trace based on the time and speed data from the 

dynamometer. Record speed to at least the nearest 0.01 mph and time to at least the nearest 0.01

s.

(d) You may perform practice runs for operating the vehicle and the dynamometer 

controls to meet the driving tolerances specified in §1066.430 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.
Page 917 of 995

(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 

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 force with the test results.

(g) For vehicles which provide four-wheel drive or all-wheel drive operation, utilize the 

vehicle’s normal (default) mode of operation. (For purposes of this paragraph (g), the term fourwheel drive includes other multiple drive axle configurations.) This may involve testing fourwheel drive or all-wheel drive on a dynamometer with a separate dynamometer roll for each 

drive axle. Alternatively, two drive axles may use a single roll, as described in §1066.210(d)(1). 

You may also test the vehicle on a single roll by deactivating the second set of drive wheels, but 

only if this mode of operation does not decrease emissions or energy consumption relative to 

normal in-use operation. We may test such vehicles in four-wheel or all-wheel mode on one or 

more rolls to confirm that the alternate dynamometer procedures did not decrease emissions.

(h) Determine test weight as follows:

(1) For vehicles at or below 14,000 pounds GVWR, determine ETW as described in 

§1066.810. 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. This is 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.

§1066.420 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:
Page 918 of 995

(1) At the beginning of the test cycle, start the vehicle according to the procedure 

described in the owners manual. In the case of hybrid vehicles, 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 hybrid vehicles,

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 exhaust tube 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:

(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 show that your vehicles comply with standards. Send us written 

notification describing these changes along with supporting rationale.
Page 919 of 995

(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 

operation with stop-start functions where the engine stops when the brake is applied below a 

certain threshold speed and restarts upon release of the brake.

(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 stop-start functions where the engine stops when the clutch is disengaged 

below a certain threshold speed and restarts upon reengagement of the clutch.

(4) Operate the vehicle with the appropriate accelerator pedal movement necessary to 

achieve the speed versus time relationship prescribed by the driving schedule. Avoid smoothing 

speed variations and excessive accelerator pedal perturbations.

(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 with minimum time. If the vehicle cannot accelerate at the specified rate, 

operate it at maximum available power until the vehicle speed reaches the value prescribed for 

that time 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 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 during testing as long as both shift schedules are included in the application for 

certification. In this case, we may use the shift schedule based on the shift pattern described in 

the owners manual.

§1066.425 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.
Page 920 of 995

(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 §1066.430(i) 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.
Page 921 of 995

Table 1 of §1066.425–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

FTP1

and 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.

(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.
Page 922 of 995

(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.

(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.
Page 923 of 995

(h) Proceed with the test sequence described in §1066.430.

§1066.430 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 without exhaust measurements, 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, provided that 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 §1066.420(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.
Page 924 of 995

v. Figure 1 of §1066.430—Example of the allowable ranges for the driver’s trace.

1.0 s

Time

Sp

e

e

d

Allowable 

Range

2.0 mph

2.0 mph

1.0 s
Page 925 of 995

vi. Figure 2 of §1066.430—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.

(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, any 

electronic integrating devices, and 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 subpart I 

of this part:

(i) Shut down the vehicle if it is part of the test cycle or if testing is complete.

(ii) 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 vehicle hood (if 

1.0 s

Time

S

p

e

e

d

Allowable 

Range

2.0 mph

2.0 mph

1.0 s
Page 926 of 995

applicable), and turn off the CVS or disconnect the exhaust tube from the tailpipe(s) of the 

vehicle unless otherwise instructed in the standard-setting part. If testing is complete, disconnect 

the exhaust tube from the vehicle tailpipe(s) and drive the vehicle from 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)(6) of 

this section and zero and span all batch gas analyzers as soon as practical prior to any batch 

sample analysis. You may perform this batch analyzer zero and span prior to the end of the test 

cycle or interval.

(ii) Analyze any conventional gaseous batch samples (HC, CH4, CO, NOx, and CO2) no 

later than 30 minutes after an interval or test cycle is complete, or during the soak period if 

practical. Analyze background samples no later than 60 minutes after the test cycle 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) Range validation. 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.

(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 be failures, 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. 
Page 927 of 995

(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 validate that analyzer drift does not exceed 2.0 % of the analyzer 

full scale.

(h) [Reserved]

(i) Measure and record ambient pressure. Measure and record ambient temperature 

continuously to verify that it remains within the temperature range specified in §1066.425(c)(1) 

throughout the test. Also measure humidity if required, such as for correcting NOx emissions, or 

meeting the requirements of §1066.425(d).

vii. (j) For vehicles at or below 14,000 pounds GVWR, determine overall driver 

accuracy as follows:

viii. (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).

ix. (i) Determine the Energy Economy Rating as described in Section 5.4 of SAE 

J2951. 

x. (ii) Determine the Absolute Speed Change Rating as described in Section 6.1.2 of 

SAE J2951.

xi. (iii) Calculate the Inertia Work Rating, IR, using the both the sums of the 

incremental driven and the target inertia work as described in Eq. 1066.430-1.

xii.

i i j j

j j

ID D IT T

i=1 j=1

IT T

j=1

100

n m

m

F D F D

IR

F D

 

  

 

 



 

 



Eq. 1066.430-1

Where:

i

FID = the driven inertial force over an interval i, as described by Equation 18 of SAE 

J2951.

j

FID = the target inertial force over an interval j, as described by Equation 19 of SAE 

J2951.

Di

D = the incremental driven distance over an interval i, as described by Equation 12 of 

SAE J2951.
Page 928 of 995

Dj

D = the incremental target distance over an interval j, as described by Equation 13 of 

SAE J2951.

xiii. (2) The standard-setting part may require you to provide to 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.

xiv.

xv.Subpart F—Hybrids and Electric Vehicles

§1066.501 Overview.

For HEV, PHEV, and pure electric vehicle (EV), use the following procedures:

(a) Correct the results for Net Energy Change of the RESS as follows: 

(1) For vehicles at or below 14,000 pounds GVWR, follow SAE J1711 (incorporated by

reference in §1066.1010) except as noted in this paragraph (a). Use ±1 % of reading or ±0.3 % 

of full scale, whichever is greater, in place of the current measurement accuracy in Section 4.2a 

of SAE J1711.

(2) For vehicles above 14,000 pounds GVWR, follow SAE J2711 (incorporated by 

reference in §1066.1010) for requirements related to charge-sustaining operation.

(3) For pure EVs, irrespective of GVWR, follow SAE J1634 (incorporated by reference 

in §1066.1010).

(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.

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.
Page 929 of 995

(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 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.

§1066.610 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) For composite emission calculations over multiple test intervals and corresponding 

weighting factors, see the standard-setting part.

(c) To calculate total mass emissions, multiply a concentration by its respective flow and 

density as specified in Eq. 1066.610-1. Before calculating mass emissions as specified in 

paragraph (d) and (e) of this section, perform the following sequence of preliminary calculations 

to correct recorded concentration measurements:

(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 §1066.665 for 

NMOG. For emission testing of vehicles above 14,000 pounds GVWR, with fuels that contain 

25% or more oxygenated compounds by volume, calculate HC concentrations, including dilution 

air background concentrations, as described in 40 CFR part 1065, subpart I, for THCE and 

NMHCE.

(5) Correct all NOx emission values for test cell ambient air humidity as described in 

§1066.630.

(6) Correct all gaseous concentrations for dilution air background as described in 

§1066.620.

(7) Correct all PM filter masses for sample media buoyancy as described in 40 CFR 
Page 930 of 995

1065.690.

(d) Calculate the emission mass of each gaseous pollutant using the following equation:

m V [emission] mix [emission] [emission]      x c

Eq. 1066.610-1

Where:

m[emission] = emission mass over the test interval.

Vmix = total dilute exhaust volume over the test interval at standard reference conditions, 

corrected for any volume removed for emission sampling and the addition of secondary dilution 

air (if applicable).

ρ[emission] = density of the appropriate chemical species as given in §1066.1005(f).

x[emission] = measured emission concentration in the sample, after dry-to-wet and 

background corrections.

c = 10-2for emission concentrations % and 10-6for emission concentrations in ppm.

Example:

Vmix = 170.878 m

3

(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) The calculation of PM is dependent on how many PM filters are used (for example as 

described in §1066.822(b)), 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. 1066.610-2
Page 931 of 995

Where:

mPM = mass of particulate matter emissions over the test interval, as described in 

§1066.820(b)(1), (2), and (3).

Vmix = total dilute exhaust volume over the test interval at standard reference conditions , 

corrected for any volume removed for emissions sampling and the addition of secondary dilution 

air (if applicable).

Vsdastd = total volume of secondary dilution air flow sampled through the filter over the 

test phase at 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 §1066.820(b)(4), calculate mPM

using the following equation:

 

 

 

 

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. 1066.610-3

Where:

mPM = mass of particulate matter emissions over the entire FTP as sampled according to 

§1066.820(b)(4).
Page 932 of 995

Vmix = total dilute exhaust volume over the test interval at standard reference conditions, 

corrected for any volume removed for emissions sampling and the addition of secondary dilution 

air (if applicable).

V[interval]-PMstd = total volume of dilute exhaust sampled through the filter over the test 

interval (ct = cold transient, s = stabilized, ht = hot transient) at 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) at 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.

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 m3

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 §1066.820(b)(5), calculate mPM

using the following equation:
Page 933 of 995

       

 

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

   

  

     



 

Eq. 1066.610-4

Where:

mPM = mass of particulate matter emissions over the entire FTP as sampled according to 

§1066.820(b)(5).

Vmix = total dilute exhaust volume over the test interval at standard reference conditions, 

corrected for any volume removed for emissions sampling and the addition of secondary dilution 

air (if applicable).

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) at 

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) at 

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.

Example:

Vmix = 972.121 m

3

Vct-PMstd = 0.925 m

3

Vct-sdastd = 0.529 m3

Vcs-PMstd = 1.968 m

3

Vcs-sdastd = 1.123 m

3

Vht-PMstd = 1.122 m

3

Vht-sdastd = 0.641 m3

Vhs-PMstd = 1.967 m

3

Vhs-sdastd = 1.121 m

3
Page 934 of 995

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 = 0.00155 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.

(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. 1066.610-5

Where:

V[flow]std = total volume of flow at the flow meter at standard reference conditions.

V[flow]act = total volume of flow 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 = average temperature of the dilute exhaust sample at the flow meter inlet.

Example:

VPMact = 1.071 m

3

pin = 101.7 kPa
Page 935 of 995

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. 

1066.610-6 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   CVSstd V V gasstd   PMstd Vsdastd

Eq. 1066.610-6

Where:

VCVSstd = total dilute exhaust volume over the test interval at the flow meter at standard 

reference conditions.

Vgasstd = total volume of sample flow through the gaseous emission bench over the test 

interval at standard reference conditions.

VPMstd = total volume of dilute exhaust sampled through the filter over the test interval at 

standard reference conditions.

Vsdastd = total volume of secondary dilution air flow sampled through the filter over the 

test interval at standard reference conditions.

Example:

Using Eq. 1066.610-5

VCVSstd = 170.451 m3, where VCVSact = 170.721 m3, pin = 101.7 kPa, and Tin = 294.7 K

Using Eq. 1066.610-5

Vgasstd = 0.028 m3, where Vgasact = 0.033 m3, pin = 101.7 kPa, and Tin = 340.5 K

Using Eq. 1066.610-5
Page 936 of 995

VPMstd = 0.925 m3, where VPMact = 1.071 m3, pin = 101.7 kPa, and Tin = 340.5 K

Using Eq. 1066.610-5

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

§1066.620 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. 1066.620-1

Where:

x[emission]dexh = measured emission concentration in dilute exhaust (after dry-to-wet 

correction for dry measurements).

x[emission]bkgnd = measured emission concentration in the dilution air (after dry-to-wet 

correction for dry measurements).

DF = dilution factor 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) Determine the dilution factor, DF, over the test interval using the following equation:
Page 937 of 995

Eq. 1066.620-2

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. 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 that measure PM using the following equation:

CO2 NMHC CH4 CO

1

1 3.76 1 ( )

2 4 2

DF

x x x x

  



   

                
Page 938 of 995

PMstd

exhstd

V

DF

V



Eq. 1066.620-3

Where:

VPMstd = total dilute exhaust volume sampled through the filter over the test interval at 

standard reference conditions.

Vexhstd = total exhaust volume sampled from the vehicle at standard reference conditions.

Example:

VPMstd = 170.9 m3

Vexhstd = 15.9 m

3

170.9 11.1

15.4

DF  

(d) Determine the time-weighted dilution factor, DFw, over the duty cycle using the 

following equation:

i

i 1

w

i

i 1 i

1

N

N

t

DF

t

DF













Eq. 1066.620-4

Where:

N = number of test intervals.

i = test interval number

t = duration of the test interval.

DF = dilution factor over the test interval.

Example:
Page 939 of 995

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         

                

§1066.630 NOx intake-air humidity correction.

See the standard-setting part to determine if you may correct NOx emissions for the 

effects of intake-air humidity. Correct NOx emissions for intake-air humidity as described in this 

section. See §1066.610(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 any

reciprocating engines for the following test cycles:

(1) Calculate a humidity correction using a time-weighted mean value for ambient 

humidity over the test interval. Calculate absolute ambient humidity in grams H2O vapor per 

kilogram of dry air using the following equation:

 

H2O d

air atmos d

1000 % 0.01

% 0.01

M p RH H

M p p RH

   



   

Eq. 1066.630-1

Where:

MH2O = molar mass of H2O, in g/mol.

pd = saturated vapor pressure at the ambient dry bulb temperature, in kPa.

RH% = relative humidity of ambient air, in %.

Mair = molar mass of air, in g/mol.
Page 940 of 995

patmos = atmospheric pressure, in kPa.

Example:

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. 1066.630-2

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 = absolute humidity, from paragraph (a)(1) of this section.

Example:

H = 7.14741 g H2O vapor/kg dry air

xNOxdexh = 1.21 ppm
Page 941 of 995

 

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.

§1066.640 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.

§1066.650 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 calculations. 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:

ref in std

rev

nPDP in std

Q T p

V

f p T

 



 



Eq. 1066.650-1

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.
Page 942 of 995

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. 1066.650-2

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.
Page 943 of 995

Example:

nPDP f = 1205.1 r/min = 20.085 r/s

out p = 100.103 kPa

in p = 98.290 kPa

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 PDP 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 §1066.650–

Example of PDP calibration data

nPDP f

(r/

s)

a1 

(m3/s)

a0 

(m3/r)

12

.6

0.

841

0.

056

16

.5

0.

831

-

0.013

20

.9

0.

809

0.

028

23

.4

0.

788

-

0.061
Page 944 of 995

(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 §1066.652.

(b) SSV calibration. Perform the following steps to calibrate an SSV flow meter:

(1) Calculate the Reynolds number, Re#, for each reference volumetric flow rate, Qm-ref



, 

using the throat diameter of the venturi, dt. Assume an initial value for Cd = 0.98 to calculate 

Qm-ref



. Because the dynamic viscosity, , is needed to compute Re#, you may use your own 

fluid viscosity model to determine for your calibration gas (usually air), using good 

engineering judgment. Alternatively, you may use the Sutherland three-coefficient viscosity

model to approximate , as shown in the following sample calculation for Re#:

# m-ref

t

4 Q

Re =

  d



 



Eq. 1066.650-3

Where, using the Sutherland three-coefficient viscosity model:

3

2

in 0

0

0 in

T T S

T T S

 

    

           

Eq. 1066.650-4

Where:

 = Dynamic viscosity of calibration gas.

0 = Sutherland reference viscosity.

T0 = Sutherland reference temperature.

S = Sutherland constant.
Page 945 of 995

Table 4 of §1065.640–

Sutherland three-coefficient viscosity model parameters

G

asa



0

T

0

S

Tem

p range 

within ±2 % 

error

Pr

essure limit

k

g /(m∙s) K K K

k

Pa

A

ir

1

.716∙10-5

2

73

1

11

170 

to 1900

≤ 

1800

C

O2

1

.370∙10-5

2

73

2

22

190 

to 1700

≤ 

3600

H

2O

1

.12∙10-5

3

50

1

064

360 

to 1500

≤ 

10000 

O

2

1

.919∙10-5

2

73

1

39

190 

to 2000

≤ 

2500

N

2

1

.663∙10-5

2

73

1

07

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.

Example:

0 = 1.716∙10-5kg/(m∙s) = 1.716∙10-2g/(m∙s)
Page 946 of 995

T0 = 273.11 K

S = 110.56 K

3

2

2 298.15 273.11 110.56 1.716 10

273.11 298.15 110.56



     

            

 = 1.837∙10-2g/(m∙s)

dt = 152.4 mm = 0.1524 m

Tin = 298.15 K

#

2

4 1658.476

3.14159 0.1524 1.837 10

Re = 



  

Re#= 7.541∙105

1

2

2 1

m-ref q d 4

1

t

p

Q K C Y d





  

        



Eq. 1066.650-5

Where:

Qm-ref

& = air flow rate of the reference flow meter, in g/s.

Kq = 0.0021074

Cd = discharge coefficient.

Y = expansion factor, as calculated in paragraph (b)(2) of this section.

dt = venturi throat diameter.

β = ratio of venturi throat diameter to approach pipe diameter. If the calibration venturi is 

used at the tunnel inlet (free standing), then assume a value of β = 0. If the SSV is installed in 

the CVS tunnel, use the actual inside tunnel diameter and the throat diameter to compute β, 

where β is the ratio of venturi throat to inlet diameters.

ρ1 = density of air at inlet conditions, in kg/m3, as determined in paragraph (b)(3) of this 

section.

Δp = pressure drop between inlet and throat, in kPa.
Page 947 of 995

(2) Calculate Y using the following equation:

1

1 2

2 4

k

2

4

1 1

1 1 1

k

k

k

k r Y r

k r

r





  

   

                         

                 

Eq. 1066.650-6

Where:

in

1

p

r

p



 

Eq. 1066.650-7

pin = absolute static pressure at the venturi inlet.

k = ratio of specific heats (1.40 for air).

Example:

Δp = 1.375 kPa

pin = 98.575 kPa

1.375 1 0.986

98.575

r   

β = 0

k = 1.4

1

1.4 1 2

2 1.4 4

1.4

2

4 1.4

1.4 1 0.986 1 0 0.986

1.4 1 1 0.986 1 0 0.986

Y

  

   

             

                             

Y = 3.764

(3) Calculate ρ1 using the following equation:

in mix

1

in

p MW

R T








Page 948 of 995

Eq. 1066.650-8

Where:

Tin = temperature at the venturi inlet.

R = 8.314472 J/(mol∙K)

MWmix = the molecular weight of the mix, as calculated in paragraph (b)(4) of this 

section.

Example:

Tin = 298.15 K

in mix

1

in

p MW

R T









ρ1 = 1.1444 (kg∙kPa)/J = (kPa∙s2)/m2

(4) Calculate MWmix as follows:

  mix 2 MW MWair 1 H2O H O H2O     x MW x

Eq. 1066.650-9

Where:

MWair = 28.964 kg/mol

xH2O = amount of H2O in the dilution air, determined as described in 40 CFR 1065.645.

MWH20 = 18.015 kg/mol

Example:

xH2O = 0.0169 mol/mol

MWmix   28.964 1 0   .0169 18.0150.0169

MWmix = 28.7789 kg/mol
Page 949 of 995

(5) Create an equation for Cd versus Re#using the results from the calibraiton. For the 

equation, you may use any mathematical expression, but a power series, least-squares fit 

polynomial equation may result in the best fit. 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. 1066.650-10

(6) Calculate Cd using Eq. 1066.650-10, or an equivalent equation, for any Re# within the 

calibrated range of the inline SSV. Use this Cd value to calculate a final Qm



for both the 

calibration flow meter and the inline SSV.

(7) Compute the percent difference in air flow between the calibration flow meter and the 

inline SSV. If the difference in percent of point is ≤ 1.0 %, you may use the equation to 

determine Cd for the emission test as described in §1066.652(b).

(8)If the difference is greater than 1.0%, you must calculate a new Cd for the inline

venturi as follows:

m-ref

dnew

m-SSV

Q

C =

Q





Eq. 1066.650-11

Where:

Cdnew = new discharge coefficient.

Qm-ref

 = air flow rate of the reference flow meter, kg/min.

Qm-SSV

 = the theoretical calculated air flow rate based on the inline SSV conditions with 

Cd set equal to 1, kg/min.

(9) Calculate # Renew based on the calibrated venturi flow determined with Cdnew and the 

in-tunnel SSV properties using Eq. 1066.650-3.

(10) Recalculate a new calibration curve for Cdnew versus # Renew for the inline SSV as 

described in paragraphs (b)(5) through (7) of this section.

(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 
Page 950 of 995

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. 1066.650-12

Where:

Qrefstd

& = mean flow rate from the reference flow meter, at 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 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. 1066.652-7, 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. 1066.650-13

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 
Page 951 of 995

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 1066.652-7, 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 the CFV 

pressure ratio. Based on the calibration data selected to meet the criteria for 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. 1066.650-8 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.

§1066.652 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 §1066.650, 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 volumetric 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 §1066.650(a), 

to calculate volumetric flow rate, Q&as follows:

nPDP

rev std in

in std

V T p

Q f

T p

 

 





Eq. 1066.652-1

Where:

fnPDP = pump speed.
Page 952 of 995

Vrev = PDP volume pumped per revolution.

Tstd = standard temperature = 293.15 K.

pin = static absolute pressure at the PDP inlet.

Tin = pump inlet absolute temperature.

pstd = standard pressure= 101.325 kPa.

out p = static absolute pressure at the PDP outlet.

nPDP

1 out in

rev 0

out

a p p V a

f p



  

Eq. 1066.652-2

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 m

3

/r

0.06383 293.15 98.575 12.58

323.5 101.3

Q

 

 





Q&= 0.7079 m3/s

(b) SSV volumetric flow rate. Based on the Cd versus Re#equation you determined 

according to §1066.650(b), calculate SSV volumetric flow rate, Vmix, during an emission test as 

follows: 
Page 953 of 995

2

q d

1

4

1

t

s

K C Y d

Q p 

 

 

   





Eq. 1066.652-3

Where:

Q&= air flow rate of flow meter, in m

3

/min.

Kq = 0.0021074.

ρs = density of air at standard conditions = 1.2041 kg/m3.

Cd = discharge coefficient.

Y = expansion factor, as determined using Eq. 1066.650-6.

dt = venturi throat diameter, in mm.

β = ratio of venturi throat diameter to approach pipe diameter.

ρ1 = density of air at inlet conditions, in kg/m3, as determined using Eq. 1066.650-8.

Δp = pressure drop between inlet and throat, in kPa.

(c) CFV volumetric 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 calibration coefficient, Kv, for each venturi, calculate the individual 

volumetric flow rates through each venturi and sum all their flow rates to determineQ&. If you 

use multiple venturis and you calibrated each combination of venturis, calculate Q&using the Kv

that was determined for that combination of venturis.

(1) To calculate volumetric flow rate through one venturi or a combination of venturis, 

use the mean Kv you determined according to §1066.650(c) and calculate the appropriate

volumetric flow rate, Q&, during an emission test as follows:

v in

in

K p Q =

T





Eq. 1066.652-7

Where:

Q&= air flow rate of flow meter, in m3/s.
Page 954 of 995

Kv = flow meter calibration coefficient, in m3∙K1/2/(kPa∙s).

Tin = temperature at the venturi inlet, in K.

pin = absolute static pressure at the venturi inlet, in kPa.

Example: 

Kv = 0.074954 m3∙K1/2/(kPa∙s)

pin = 99.654 kPa

Tin = 353.15 K

0.074954 99.654

353.15

Q







Q = 0.39748 m

3

/s

§1066.665 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 emissions. Calculate 

NMOG 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. 1066.665-1

Where:

mNMOG = the sum of the mass of NMOG in the exhaust.

mNMHC = the mass of NMHC and all oxygenated hydrocarbons (OHCs) in the exhaust, as 

determined using Eq. 1066.610-1. Calculate NMHC mass based on ρNMHC.
Page 955 of 995

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. 1066.610-1.

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 1065.665.

(b) The following example shows how to determine NMOG emissions as described in 

paragraph (a) of this section for (OHC) compounds including ethanol (C2H5OH), methanol 

(CH3OH), acetaldehyde (C2H4O), and formaldehyde (C2HO) as C1-equivalent concentrations:

mNMHC = 0.0125 g

mCH3OH = 0.0002 g

mC2H5OH = 0.0009 g

mHCHO = 0.0001 g

mC2H4O = 0.00005 g

RFCH3OH[THC-FID] = 0.63

RFC2H5OH[THC-FID] = 0.75

RFHCHO[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

ρHCHO = 1248.21 g/m3

ρC2H4O = 915.658 g/m3

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

 

     

   

  

 

  
Page 956 of 995

mNMOG = 0.013273

(c) For ethanol-gasoline blends less than 25 % ethanol by volume, you may calculate 

NMOG emissions 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 test cycle NMHC emission rate using the following equation:

NMOGhot NMHChot e e  1.03

Eq. 1066.665-2

Where:

eNMOGhot = mass emission rate of NMOG over the hot running test cycle.

eNMHChot = mass emission rate of NMHC over the hot running test cycle, calculated using

ρNMHC-liq.

Example:

eNMHChot = 0.025 g/mi

NMOGhot 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. 1066.665-3

Where:

eNMOGcomp = weighted composite mass emission rate of NMOG.

eNMHCcomp = weighted composite mass emission rate of NMHC, calculated using ρNMHCliq.

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.
Page 957 of 995

Example:

eNMHCcomp = 0.025 g/mi

VPEtOH = 15.1 %

eNMOGcomp   0.025 1.0302   0.0071 15.1  0.0284 g/mi

(3) You may determine NMOG for the complete FTP cold-start test interval 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-FTPct   NMHC-FTPct 1.0246   0.0079 VPEtOH 

Eq. 1066.665-4

Where:

eNMOG-FTPct = mass emission rate of NMOG over the FTP cold start test interval.

eNMHC-FTPct = mass emission rate of NMHC over the FTP cold-start test interval,

calculated using ρNMHC-liq.

VPEtOH = volume percentage of ethanol in the test fuel.

Example:

eNMHC-FTPct = 0.052 g/mi

VPEtOH = 15.1 %

eNMOG-FTPct   0.052 1.0246   0.0079 15.1  0.0595 g/mi

(4) You may determine NMOG for the FTP stabilized test interval for either the cold-start

or 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-FTPcs-hs   NMHC-FTPcs-hs 1.1135   0.001 VPEtOH 
Page 958 of 995

Eq. 1066.665-5

Where:

eNMOG-FTPcs-hs = mass emission rate of NMOG over the FTP stabilized test interval.

eNMHC-FTPcs-hs = mass emission rate of NMHC over the FTP stabilized test interval,

calculated using ρNMHC-liq.

VPEtOH = volume percentage of ethanol in the test fuel.

(5) You may determine NMOG for the complete FTP hot-start test interval 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. 1066.665-6

Where:

eNMOG-FTPht = mass emission rate of NMOG over the FTP hot-start test interval.

eNMHC-FTPht = mass emission rate of NMHC over the FTP hot-start test interval, calculated 

using ρNMHC-liq.

VPEtOH = volume percentage of ethanol in the test fuel.

(d) You may take the following additional steps when determining fuel economy and 

CREE under 40 CFR part 600:

(1) Calculate NMOG by interval using Eq. 1066.665-3 for individual bag measurements 

from the FTP.

(2) Calculate NMOG for two-bag FTPs using Eq. 1066.665-3 for hybrid-electric vehicles 

as described in 40 CFR 600.114.

(e) We consider NMOG emission values for diesel-fueled vehicles, CNG-fueled 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.
Page 959 of 995

Record the following information for each test:

(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 

§1066.430(j).

(e) Driver and equipment operators.

(f) Vehicle information as applicable, including identification number, model year, 

applicable emission standards, vehicle model, vehicle class, carline, 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, gross vehicle 

weight rating, equivalent 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 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 interval of the exhaust test and the 

following additional information:

(1) CFV and SSV Vmix for each interval of the exhaust test.

(2) PDP. Test measurements required to calculate Vmix for each interval of the exhaust 

test.
Page 960 of 995

(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 

particulate sampling.

(p) The maximum gas temperature over the course of the test within 20 cm upstream or 

downstream of the sample media (e.g., filter).

(q) If applicable, the temperature of the heated FID, the gas in the heated sample line, and 

the heated filter.

(r) Gas meter or flow measurement instrumentation readings at the start and end of 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 particulate 

sample media (e.g., filter) are stabilized.

(u) For vehicles fueled by natural gas, the test fuel composition, including all carboncontaining compounds (except CO); e.g. CO2, of the natural gas-fuel used during the test. 

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) Additional required records for liquefied petroleum gas-fueled vehicles. For vehicles 

fueled by liquefied petroleum gas, the test fuel composition, including all carbon-containing 

compounds (except CO); e.g. CO2. Each hydrocarbon compound present, through C4

compounds, shall be individually reported. C5 and heavier hydrocarbons may be reported as a 

group. Record C1 and C4 compounds individually. You may record C5 and heavier hydrocarbon 

compounds together.

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 testing motor vehicles at a 

nominal temperature of 20 °C (68 °F); these procedures apply for motor vechicles as described 

in 40 CFR part 86, subpart S, and 40 CFR part 600. For other vehicles, see the standard-setting 

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 §1066.630(a) for cold-temperature 
Page 961 of 995

testing.

§1066.710 Cold-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 

driving schedule (see §1066.801). 

(a) Follow the exhaust emission measurement procedures specified in §§1066.410 

through 1066.430 and §1066.820(d), subject to the following exceptions and additional 

provisions:

(1) Measure and control ambient conditions as specified in paragraph (b) of this 

section.

(2) Precondition and stabilize the vehicle as specified in paragraphs (c) and (d) of 

this section. Ensure that there is no precipitation or dew on the vehicle before the 

emission test.

(3) For dynamometers that have independently heated bearings, start the emission 

test within 20 minutes after the end of dynamometer warm up; for other dynamometers, 

start the emission test within 10 minutes after the end of dynamometer warm up.

(5) 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 average temperature during the sampling period must be (−7.0 ±1.7) °C. 

Instantaneous temperature values may be above −4.0 °C or below −9.0 °C, but not for 

more than 3 minutes at a time.

(2) Ambient temperature for preconditioning. Ambient temperatures must be 

between (−14.0 and −1.0) °C throughout the preconditioning period. 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. Use good engineering judgment to demonstrate that you 

meet the specified temperature tolerances specified in this paragraph (b)(2).
Page 962 of 995

(3) Ambient humidity. Maintain humidity low enough to prevent condensation on 

the dynamometer rolls during testing.

(c) Take the following steps to prepare and precondition vehicles for testing under this 

section:

(1) Prepare the vehicle as described in §1066.814(a). 

(2) Fill the fuel tank to approximately 40 % of the manufacturer’s nominal fuel 

tank capacity with the appropriate test fuel for low-temperature testing specified 40 CFR 

part 1065, subpart H. If the leftover fuel in the fuel tank before the refueling event does 

not meet these specifications, drain the fuel tank before refueling. The temperature of the 

dispensed test fuel must be at or below 15.5 °C. 

(3) You may start the preconditioning drive once the fuel in the fuel tank reaches 

(−7.0 °C ±5.6) °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 to −1.0) °C in the 5 minutes following the preconditioning drive.

(iv) Do not manually purge or load the evaporative canister.

(d) Soak the vehicle for (12 to 36) hours to stabilize it at test temperatures before starting 

the emission test as described in this paragraph (d). 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 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 soak period; use these measured values to calculate an 

hourly average temperature. Each hourly average temperature must be (−7.0 °C ±2.8) 

°C. Instantaneous ambient temperatures during the soak period may be above −1.0 °C or 

below −12.0, but not for more than 3 minutes at a time. 

(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 (−7 ±1.7) °C; 

measure oil temperature at one or more points away from the side or bottom surfaces of 
Page 963 of 995

the oil pan. Each oil temperature measurement must be within the specified range before 

stabilization is complete. Once the vehicle reaches this stabilized condition, hold 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 motor vehicles at 

or below 14,000 pounds GVWR, including 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. 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 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 hot-stabilized 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 §§1066.820 and 1066.822.

(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 (f) of 
Page 964 of 995

Appendix I of 40 CFR part 86, followed by another UDDS; see 40 CFR 86.134-96. Note that 

the New York City Cycle represents about 1.7 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 86.138-96 and a 

three-day diurnal emission test as described in 40 CFR 86.133-96. In the two-day diurnal test 

sequence, the exhaust test is followed by a low-temperature 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 nonintegrated systems, there is a preconditioning drive over the UDDS and a refueling event, 

followed by repeated UDDS driving 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 §§1066.820 and 1066.822.

(3) The Highway Fuel Economy Test (HFET). The 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 §1066.839.

(4) Cold-temperature testing. 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.

(5) Emission measurement to determine air conditioning credits for greenhouse gas 

standards. In this optional procedure, manufacturers operate vehicles over repeat runs of 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 

§1066.835.

(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 
Page 965 of 995

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 §1066.814.

(e) The following figure illustrates the FTP test sequence for measuring exhaust and 

evaporative emissions:

Figure 1 of §1066.801–FTP test sequence. 

Fuel drain and fill

Vehicle Soak

Preconditioning drive

1 hour MAX

Fuel drain and fill

Precondition canister Precondition canister

Cold start exhaust test Cold start exhaust test

10 minutes 10 minutes

Hot start exhaust test Hot start exhaust test

1-5 hours 7 minutes MAX

Running loss test Hot soak test

7 minutes max 68 - 86 °F ambient

Hot soak test

90-100 °F ambient Vehicle soak

Vehicle soak Diurnal emission test

2 heat builds in 48 hours

Diurnal emission test

3 heat builds in 72 hours

6-36 hours

12-36 hours

1 hour

6-36 hours

1 hour

6-36 hours

Start

End

End

Diesel 

Only

§1066.810 Road load power, test weight, and inertia weight class determination.
Page 966 of 995

(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:

Table 1 of §1066.810–Equivalent test weights (pounds)

Test Equival Inert
Page 967 of 995

(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 and SFTP testing, determine road load forces for each test vehicle at speeds 

between 10 and 70 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 10 mph.

§1066.814 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 as necessary to allow purging and loading of 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 remove 

the spare tire for any testing.
Page 968 of 995

§1066.820 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.

(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 §1066.822 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 §1066.620 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 3 bags or 4 

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.
Page 969 of 995

(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.

(4) You may apply the provisions of paragraph (b) of this section for any gaseous batch 

measurement, consistent with good engineering judgment.

(d) Test sequence. Follow the exhaust emission measurement procedures specified in 

§§1066.410 through 1066.430, 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 40 CFR 86.132. Initiate the cold-start test 

following the 12 to 36 hour soak period.

(ii) Start sampling and recording simultaneously with starting the vehicle. Fifteen 

seconds after the engine starts, place the transmission in gear. Twenty seconds after the engine 

starts, begin the initial vehicle acceleration of the driving schedule.

(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 40 CFR part 

86, subpart B, and §1066.801 for continuing to evaporative or refueling tests. 
Page 970 of 995

§1066.822 Composite calculations for FTP exhaust emissions.

(a) Determine the mass of exhaust emissions of each pollutant for each FTP test interval

as described in §1066.610.

(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. 1066.822-1

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.

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 §1066.820(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

   

             
Page 971 of 995

Eq. 1066.822-2

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. 1066.610-2.

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. 1066.610-2. 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 §1066.820(b)(4):

   

PM

PM-FTPcomp

ct cs ht 0.43 0.57

m

e

D D D



   

Eq. 1066.822-3

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. 1066.610-3.

(3) Use the following equation for PM measured as described in §1066.820(b)(5):

   

PM

PM-FTPcomp

ct cs ht hs 0.43 0.57

m

e

D D D D



    

Eq. 1066.822-4

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. 1066.610-4.

§1066.830 Supplemental Federal Test Procedures; overview.

Sections 1066.831 and 1066.832 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. 
Page 972 of 995

(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 (§1066.832), 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)(iii). 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 866 seconds of the UDDS (bag 2).
Page 973 of 995

(C) The HFET driving schedule.

(D) US06 driving schedule or, for heavy-duty vehicles above 10,000 pounds GVWR, 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 for 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. 1066.620-4 

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.

(f) Follow the exhaust emission measurement procedures specified in §§1066.410 

through 1066.430, subject to the following exceptions and additional provisions:

(1) Following the preconditioning specified in §1066.830, 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:
Page 974 of 995

(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 may be certified using only 

the highway portion of the US06 driving schedule. See 40 CFR 86.1816. 

(3) Turn the engine off 2 seconds before the end of the driving schedule. 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 recorded data.

(4) Correct calculated NOx emissions as described in §1066.630(a)(1).

§1066.832 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) Keep the vehicle in an environment meeting the conditions described in paragraph (e) 

of this section throughout the preconditioning sequence. 

(b) Warm up the vehicle to a stabilized condition as follows: 

(1) Push or drive the test vehicle onto the dynamometer.

(2) Operate 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.

(3) 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.

(c) Follow the exhaust emission measurement procedures specified in §§1066.410 

through 1066.430, subject to the following exceptions and additional provisions:

(1) Close the vehicle’s windows before testing.

(2) The test cell and equipment must meet the specifications in paragraph (d) of this 

section. Measure and control ambient conditions as specified in paragraph (e) of this section.

(3) 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 
Page 975 of 995

A/C temperature to full cool (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.

(4) Place the vehicle in gear 15 seconds after engine starting. Follow the SC03 driving 

schedule. 

(5) Turn the engine off 2 seconds before the end of the driving schedule. 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.

(6) Correct calculated NOx emissions as described in §1066.630(a)(2).

(d) The following requirement apply for the test cell and cooling fan configuration:

(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) before each test.

(e) Maintain ambient conditions as follows: 

(1) Ambient temperature. Measure and record ambient temperature in the test cell at least 

once every 30 seconds during the sampling period. Control ambient temperature during 

emission sampling to 35.0 ±3.0 °C throughout the test and (33.6 to 36.4) °C on average. 

(2) Ambient humidity. Measure and record ambient humidity in the test cell at least once 

every 30 seconds during the sampling period. Control ambient humidity during emission 

sampling as described in §1066.425(d).

(3) Conditions before and after testing. Use good engineering judgment to demonstrate 

that you meet the specified instantaneous temperature and humidity tolerances in paragraphs 

(e)(1) and (2) of this section at all times before and between emission measurements.

(4) 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 §1066.832–Recommended Spectral Distribution
Page 976 of 995

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/m2. 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.

(C) Linearity of ± 0.5 %.

(D) 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 the intensity predicted from the zero-degree intensity and the cosine of the incident 

angle.

(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 (e)(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.
Page 977 of 995

§1066.835 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 

§86.832(d). 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.

(c) Ambient conditions. Measure and control ambient conditions as specified in 

§86.832(e), except that you must control ambient temperature during emission sampling to 25.0 

±3.0 °C throughout the test and (23.6 to 26.4) °C on average. 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 

and passenger’s headrests. 

(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.

(2) For manual systems, select A/C mode 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 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 at the dashboard air outlet.

(f) Test procedure. Follow the exhaust emission measurement procedures specified in 

§§1066.410 through 1066.430, subject to the following exceptions and additional provisions:

(1) Prepare the vehicle for testing according to 40 CFR 86.132-00 (a) through (g).

(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. 

(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 
Page 978 of 995

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. Follow the SC03 driving 

schedule. Place the vehicle in gear 15 seconds after engine starting. 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, but leave the vehicle’s windows open and turn off the vehicle’s air conditioner and the 

solar heating throughout the test run.

(g) Calculations. (1) Determine the mass of CO2 emissions for each of the two test 

intervals as described in §1066.610.

(2) Calculate the composite mass-weighted emissions of CO2, e[CO2]-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. 1066.835-1

Where:

mSC03 = mass emissions from the SC03 test interval, in grams.

mHFET = mass emissions from the HFET test interval, in grams.

DSC03 = measured driving distance during the SC03 test interval, in miles.

DHFET = measured driving distance during the HFET test interval, in miles.

(h) Recordkeeping. In addition to the information specified in §1066.695, you must 

record the following information for each vehicle tested: interior volume, climate control system 

type and characteristics, refrigerant used, compressor type, and evaporator/condenser 

characteristics.
Page 979 of 995

§1066.839 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 1066.430, 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.

§1066.840 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. 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.

(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 
Page 980 of 995

gas cap and the evaporative canister. The evaporative system test port available on some 

vehicles is an example of an effective attachment point.

(c) 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.

(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:

   

0.5057

gas

eff

1 2 1 2

7.844

V

D

p p p p

G T

   

 

  

  

Where:

Deff = effective leak diameter, in inches.

Vgas = volumetric flow of gas, in m3/s.

p1 = inlet pressure to orifice, in kPa.

p2 = atmospheric pressure, in kPa.

G = specific gravity of N2 at atmospheric pressure and 15.5 °C

T = temperature of flowing medium, in K.
Page 981 of 995

(9) You may perform any number of replicate tests, but all the tests for a vehicle must use 

the same attachment point. The average value of replicate tests is the official result for a given 

vehicle.

(10) You may use special or alternative test procedures as described in 40 CFR 

1065.10(c).

(d) Equipment calibration. Use good engineering judgment to calibrate the leak check 

device.

Subpart J—[Reserved]

Subpart K—Definitions and Other Reference Material

§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:

Bag 1 means relating to the first 505 s 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 s of the FTP cold-start test interval.

Bag 3 means relating to the first 505 s of the FTP hot-start test interval. 

Bag 4 means relating to the last 867 s 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.
Page 982 of 995

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 §1066.665. Note that for this part, the organic gases are summed on a 

mass basis without any adjustment for photochemical reactivity.

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) Pressure at 101.325 kPa.

(2) Temperature at 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 
Page 983 of 995

the mass emissions from multiple test intervals. For example, the standard-setting 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 standard-setting 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 §1066.810.

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:

S

ymbol Quantity Unit Unit symbol

Unit in 

terms of SI base 

units

α

atomic hydrogen to 

carbon ratio mole per mole mol/mol 1

a acceleration 

feet per second 

squared or meters per second 

squared

ft/s2or 

m/s2 m∙s-2

β

atomic oxygen to 

carbon ratio mole per mole mol/mol 1
Page 984 of 995

c conversion factor

C

d

discharge coefficient

d diameter meters m m

D

F

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

I inertia pound mass or 

kilogram lbm or kg kg

I current ampere A A

i indexing variable

m mass

pound mass or 

kilogram lbm or kg kg

N total number in series

n

total number of pulses 

in a series

ρ mass density kilogram per cubic 

meter kg/m3

kg∙m-3

R

dynamometer roll 

revolutions

revolutions per 

minute rpm

2∙π∙60-1∙ 

m·m

-1

·s-1
Page 985 of 995

R

e

# Reynolds number

Q flow

cubic feet or cubic 

meter

Q

flow rate

cubic feet per 

minute or cubic meter per 

second

p pressure pascal Pa m

-1

∙kg∙s-2

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

Δ

t

time interval, period, 

1/frequency second s s

U voltage volt V

m

2

∙kg∙s3

∙A-1

v speed miles per hour or 

meters per second mph or m/s m∙s-1

V

P

volume percent

x

mass of emission over a 

test interval kilogram kg kg

y generic variable

(b) Symbols for chemical species. This part uses the following symbols for chemical 

species and exhaust constituents:
Page 986 of 995

Sym

bol Species

CH4 methane

CO carbon monoxide

CO2 carbon dioxide

NM

HC nonmethane hydrocarbon

NM

HCE nonmethane hydrocarbon equivalent

NM

OG

nonmethane organic gas

NO nitric oxide

NO2 nitrogen dioxide

NOx oxides of nitrogen

N2O nitrous oxide

O2 molecular oxygen

OH

C

oxygenated hydrocarbon

PM particulate matter

TH

C

total hydrocarbon

TH

CE total hydrocarbon equivalent
Page 987 of 995

(c) Superscripts. This part uses the following superscripts to define a quantity:

Superscript Quantity

overbar (such as 

y )

arithmetic mean

(d) Subscripts. This part uses the following subscripts to define a quantity:

Sub

script

Quantity

abs absolute quantity

act actual or measured condition

acti

nt

actual or measured condition over the speed interval

atm

os

atmospheric

b base

c coastdown

co

mp

composite

cor corrected

dex

h

dilute exhaust quantity
Page 988 of 995

dil dilute

e effective

emi

ssion

emission specie

err

or

error

exh raw exhaust quantity

exp expected quantity

fil filter

fina

l

final

flo

w

flow measurement device type

i an individual of a series

int intake

init initial quantity, typically before an emission test

ma

x

the maximum (i.e. peak) value expected at the standard 

over a test interval; not the maximum of an instrument range

me

as

measured quantity

ref reference quantity

rev revolution
Page 989 of 995

roll dynamometer roll

s settling

sat saturated condition

spa

n

span quantity

std standard conditions

test test quantity

unc

or

uncorrected quantity

w weighted

zer

o

zero quantity

(e) Other acronyms and abbreviations. This part uses the following additional 

abbreviations and acronyms: 

A/C air conditioning

ALV

W

adjusted loaded vehicle weight

CFR Code of Federal Regulations

CFV critical-flow venturi

CVS constant-volume sampler
Page 990 of 995

EPA Environmental Protection Agency

ETW equivalent test weight

EV electric vehicle

FID flame-ionization detector

FTP Federal test procedure

GC gas chromatograph

GHG greenhouse gas (including CO2, N2O, and CH4)

GV

WR

gross vehicle weight rating

HEV hybrid electric vehicle

HFE

T

highway fuel economy test

HLD

T

heavy light-duty truck

HPL

C

high pressure liquid chromatography

IBR incorporated by reference

MDP

V

medium-duty passenger vehicle

NIST National Institute for Standards and Technology

PDP positive-displacement pump
Page 991 of 995

PHE

V

plug-in hybrid electric vehicle

PM particulate matter

RES

S

rechargeable energy storage system

SAE Society of Automotive Engineers

SC03 air conditioning driving schedule

SEA selective enforcement audit

SFTP supplemental federal test procedure

SSV subsonic venturi

UDD

S

urban dynamometer driving cycle

US06 aggressive driving schedule

U.S.

C.

United States Code

(f) This part uses the following densities of chemical species:

Sym

bol Quantity1,2 g/m3 g/ft3

ρCH4 density of methane 666.905 18.8847

ρCH3

OH

density of methanol 1332.02 37.7185
Page 992 of 995

ρC2H

5OH

C1-equivalent density of ethanol 957.559 27.1151

ρC2H

4O

C1-equivalent density of acetaldehyde 915.658 25.9285

ρC3H

8

density of propane 611.035 17.3026

ρC3H

7OH

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

ρHCgaseffective density of hydrocarbon - gaseous fuel3(see 3) (see 3)

ρHCH

O

density of formaldehyde 1248.21 35.3455

ρHCliqeffective density of hydrocarbon - liquid fuel4576.816 16.3336

ρNM

HC-gas

effective density of nonmethane hydrocarbon -

gaseous fuel3

(see 3) (see 3)

ρNM

HC-liq

effective density of nonmethane hydrocarbon -

liquid fuel4

576.816 16.3336

ρNM

HCE-gas

effective density of nonmethane equivalent 

hydrocarbon - gaseous fuel3 (see 3) (see 3)

ρNM

HCE-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
Page 993 of 995

1Densities are given at 20 °C and 101.325 kPa.

2Densities for all hydrocarbon containing quantities are given in kg/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

= 0.04157∙(12.011 + (∙1.008)).

4The effective density for gasoline and diesel fuel are defined by an atomic hydrogen-tocarbon 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:

S

ymbol

Quantity mo

l/mol 

x

Arair

amount of argon in dry air 0.0

0934

x

CO2air

amount of carbon dioxide in 

dry air

0.0

00375

x

N2air

amount of nitrogen in dry air 0.7

8084

x

O2air

amount of oxygen in dry air 0.2

09445

(2) This part uses the following molar masses or effective molar masses of chemical 

species:

S

ymbol Quantity

g/mol

(10-

3

·kg·mol-1)

M

air

molar mass of dry air128.96559

M

H2O

molar mass of water 18.01528

1

See paragraph (g)(1) of this section for the composition of dry air.

(h) Prefixes. This part uses the following prefixes to define a quantity:

S

ymbol

Q

uantity

V

alue

 mi

cro

1

0

-6
Page 994 of 995

m mi

lli

1

0

-3

c ce

nti

1

0

-2

k kil

o

1

0

3

M m

ega

1

0

6

§1066.1010 Reference materials.

(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, the Environmental Protection Agency must 

publish a notice of the change 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) Society of Automotive Engineers, 400 Commonwealth Dr., Warrendale, PA 15096–

0001, (877) 606–7323 (U.S. and Canada) or (724) 776–4970 (outside the U.S. and Canada), 

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) and 

1066.310(b).

(2) SAE J1634, Electric Vehicle Energy Consumption and Range Test Procedure, 

Revised October 2012, IBR approved for §1066.501.

(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 §§1066.122 and 1066.501.

(4) SAE J2263, Road Load Measurement Using Onboard Anemometry and Coastdown 

Techniques, Revised December 2008, IBR approved for §§1066.301(b) and 1066.310(b).

(5) SAE J2264, Chassis Dynamometer Simulation of Road Load Using Coastdown 

Techniques, Issued April 1995, IBR approved for §1066.320.

(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.
Page 995 of 995

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

Standards

Page 1000 of 1000

(7) SAE J2951, Drive Quality Evaluation for Chassis Dynamometer Testing, Revised 

November 2011, IBR approved for §1066.430.

(c) National Institute of Standards and Technology, 100 Bureau Drive, Stop 1070, 

Gaithersburg, MD 20899-1070, (301) 975-6478, www.nist.gov, or inquiries@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 §§1066.20(a) and 1066.1005.

(2) [Reserved]

Dated: _______________________

_____________________________________________________

Bob Perciasepe

Acting Administrator, Environmental Protection Agency