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EO12866_Tier_3_2060-AQ86_NPRM_FRN_20130328.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 has announced the comment period and the public hearing dates for 

this proposal in a supplemental Federal Register Notice, which was published on 

[insert date of publication of supplemental notice in the Federal Register]. 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.
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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.

 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.
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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.

FOR FURTHER INFORMATION CONTACT: JoNell Iffland, Office of 

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

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

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

iffland.jonell@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this Action Apply to Me?

Entities potentially affected by this 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.
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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,

336120,

336211,

336312

3699, 

3711, 

3713, 

3714

On-highway heavy-duty engine & vehicle 

(>8,500 lbs GVWR) manufacturers

a North American Industry Classification System (NAICS).

b

Standard Industrial Classification (SIC).

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

readers regarding entities likely to be regulated by this 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 email. 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:
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 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.

 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-byrefinery 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 

Medium-Duty Passenger Vehicle Tailpipe Emissions

2. Proposed Heavy-Duty Vehicle Tailpipe Emissions Standards

3. Proposed Evaporative Emission Standards

4. Onboard Diagnostic Systems (OBD)
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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

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
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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

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
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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

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?
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A. Overview

B. Quantified Human Health Impacts

C. Monetized Benefits

D. What are the Limitations of the Benefits Analysis?

E. Illustrative Analysis of 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

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
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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. 

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.2 These compounds form ozone, PM, and 

other air pollutants, whose health and environmental effects are described in more 

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

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

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

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

 

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-OAR-2011-0135.

2 Mobile source contributions derived from inventories developed for the Final Cross-State Air 

Pollution Rule (76 FR 48208, August 8, 2011). For more information on these inventories see the 

“Technical Support Document (TSD) for the final Transport Rule, Docket ID No. EPA-HQ-OAR2009-0491, 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
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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 multipollutant reductions projected to result from the proposed Tier 3 standards. In the 

absence of additional controls, many areas 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 

 

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/

7

65 FR 6698 (February 10, 2000)
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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.

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 lowercost 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. 
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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 approved a waiver of Clean Air Act preemption for the California Air 

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

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, 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 enabling manufacturers to design a single vehicle 

for nationwide sales, thus reducing their costs of compliance. 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 

 

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.

10 The Presidential Memorandum is found at: http://www.whitehouse.gov/the-pressoffice/presidential-memorandum-regarding-fuel-efficiency-standards.

11 75 FR 14670 (March 26, 2010).
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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 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 heavyduty 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 lightand 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 
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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 fleetaverage 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 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 is 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 

 

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

below.

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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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. 

The proposed FTP and SFTP NMOG+NOX standards would be fleetaverage 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 fleet-average 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 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.15

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 101 92 83 74 65 56 47 38 30

 

15 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 phase-in would apply. This would not be a fleet-average standard. 
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MDPV

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.

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.16 Although many vehicles today are 

performing at or near the levels of the proposed standards, the data indicate that 

improvements, especially in high-load fuel control and in the durability of engine 

components, are possible. 

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

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

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

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

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 

 

16 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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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 phasein 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.

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. 
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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 fullsize 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 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 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 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
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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 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-
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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 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, 
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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 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. 
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Page 23 of 903

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 

potential 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

 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.17

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

 

17 72 FR 8434 (February 26, 2007).
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used for flexible fuel vehicle (FFV) certification, as discussed in Section IV.D.2.18 

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.

In addition to seeking comment on all aspects of the proposed new emission 

test fuel requirements, we also seek comment on whether there are other aspects of 

today’s proposed standards that, if modified, might 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 

ethanol-gasoline 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 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 

 

18 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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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 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, 
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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 gasoline-ethanol 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 non-substantive 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 

certification-related 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 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 
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Page 27 of 903

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 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 on-highway emissions of 

NOX and VOC nearly 40 percent from the level of emissions projected without Tier 

3 controls.19 

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 (including notable nationwide 

reductions in benzene concentrations) by 2030, and would immediately reduce 

ozone in 2017 when the proposed sulfur controls take effect. 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 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 

 

19 To estimate the benefits of the proposed Tier 3 rule, we perfomed air quality modeling for the year 

2030. 

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. 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. 
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Page 28 of 903

program in 2030 would be approximately $3.4 billion.21 The 2030 benefits are 2 to 

7 times the costs of the program. 

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.

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 

 

21 Costs include estimates for the proposed Tier 3 standards in all states except California.
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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 near-road concentrations of some criteria and toxic pollutants.24 More 

than 50 million people live, work, or go to school in close proximity to high-traffic 

roadways, and the average American spends more than one hour traveling each day, 

with nearly 90 percent of daily trips occurring by personal vehicle.25,26,27 Exposure 

 

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-OAR-2011-0135.

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

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
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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. 

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 

 

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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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, 

 

28 77 FR 62623 (October 15, 2012).

29 The Presidential Memorandum is found at: http://www.whitehouse.gov/the-pressoffice/presidential-memorandum-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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giving appropriate consideration to cost, energy, and safety. In addition, section 

202(k) provides EPA with authority to issue and revise regulations applicable to 

evaporative emissions of hydrocarbons from all gasoline-fueled motor vehicles 

during: (1) operation, and (2) over 2 or more days of nonuse; under ozone-prone 

summertime conditions. Regulations under section 202(k) shall take effect as 

expeditiously as possible and shall require the greatest degree of emission reduction 

achievable by means reasonably expected to be available for production during any 

model year to which the regulations apply, giving appropriate consideration to fuel 

volatility, and to cost, energy, and safety factors associated with the application of 

the appropriate technology. Further, section 206 and in particular section 206(d) of 

the Clean Air Act authorizes EPA to 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 

 

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-HQOAR-2011-0135.
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toxics at levels which have the potential to cause adverse health effects.32 In 

addition, populations who live, work, or attend school 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 

 

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

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

33

 Health Effects Institute Panel on the Health Effects of Traffic-Related Air Pollution. (2010) 

Traffic-related 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. 
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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 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 

ozone-related 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 respiratoryrelated 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.

 

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.

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

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

 

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.

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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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 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 

 

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.
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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 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 short- and 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 

 

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. 

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.
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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 from this proposed rule, which would take effect 

starting in 2017, would be helpful to states as they work to attain and 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/m3to 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-

 

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.

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-OAR-2011-0135. 

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. 
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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 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 

 

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

http://www.epa.gov/PM/naaqsrev2006.html#timeline. Accessed December 31, 2011. 

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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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 short- and 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 allergen-induced 

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 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 

 

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.
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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

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 

 

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

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. 
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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-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-

 

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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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 short-term CO exposure and 

respiratory morbidity, and inadequate to conclude that a causal relationship exists 

between long-term exposure and respiratory morbidity. 

Finally, the 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 causespecific 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 National-scale Air Toxics Assessment and have significant inventory

contributions from mobile sources.64 

a. Health Effects of Air Toxics

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 

 

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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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 10-6to 

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 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

 

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 

colony-stimulating 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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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 workers exposed to formaldehyde.86,87,88 

 

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

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. 
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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 

 

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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effects. The NRC 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

 

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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EPA most recently evaluated the toxicological and health effects literature 

related to acrolein in 2003 and concluded that the human carcinogenic potential of 

acrolein could not be determined because the available data were inadequate. No 

information was available on the carcinogenic effects of acrolein in humans and the 

animal data provided inadequate evidence of carcinogenicity.

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 

 

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. 
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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 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 

 

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. 

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.
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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

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.120,121 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.122 In 1997 

EPA classified seven PAHs (benzo[a]pyrene, benz[a]anthracene, chrysene, 

 

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.

120 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. 

121 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. 

122 International Agency for Research on Cancer (IARC). (2012). Monographs on the Evaluation of 

the Carcinogenic Risk of Chemicals for Humans, Chemical Agents and Related Occupations. Vol. 

100F. Lyon, France.
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benzo[b]fluoranthene, benzo[k]fluoranthene, dibenz[a,h]anthracene, and 

indeno[1,2,3-cd]pyrene) as Group B2, probable human carcinogens.123 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).124,125 These and similar studies 

are being evaluated as a part of the ongoing IRIS assessment of health effects 

associated with exposure to benzo[a]pyrene.

viii. 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.126

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

attributed to photochemical oxidants, including PAN.127 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 

 

123 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. 

124 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. 

125 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. 

126 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/. 

127 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 
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conclusions.128

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.129 Chronic (long 

term) exposure of workers and rodents to naphthalene has been reported to cause 

cataracts and retinal damage.130 EPA released an external review draft of a 

reassessment of the inhalation carcinogenicity of naphthalene based on a number of 

recent animal carcinogenicity studies.131 The draft reassessment completed external 

peer review.132 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.133 California EPA has released a new risk assessment for 

 

128 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 

129 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.

130 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.

131 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. 

132 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. 

133 NTP. (2011). Report on Carcinogens, Twelfth Edition. Research Triangle Park, NC: U.S. 

Department of Health and Human Services, Public Health Service, National Toxicology Program. 

499 pp.
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naphthalene, and the IARC has reevaluated naphthalene and re-classified it as 

Group 2B: possibly carcinogenic to humans.134 

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

including abnormal cell changes and growth in respiratory and nasal tissues.135 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.

136

 

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.137

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.138 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.139 According to the National Air Toxic Assessment (NATA) for 2005,140

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 

 

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

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

135 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 

136 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. 

137 U.S. EPA Integrated Risk Information System (IRIS) database is available at: www.epa.gov/iris 

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

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

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

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

140 U. S. EPA. (2011). 2005 National-Scale Air Toxics Assessment. 

http://www.epa.gov/ttn/atw/nata2005/. 
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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.141 These pollutants 

showed a large reduction in concentrations within 100 meters downwind of the 

roadway. Pollutants that showed more gradual reductions with distance from 

roadways included benzene, NO2, PM2.5, and PM10. In the review article, results 

varied based on the method of statistical analysis used to determine the trend.

For pollutants with relatively high background concentrations relative to 

near-road 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.142,143 These findings suggest a substantial roadway source of these 

carbonyls.

 

141 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.

142 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.

143 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
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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.144 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.145 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 HEI panel’s.146,147,148 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 

 

144 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. 

145 Health Effects Institute Panel on the Health Effects of Traffic-Related Air Pollution. (2010). 

Traffic-related air pollution: a critical review of the literature on emissions, exposure, and health 

effects. HEI Special Report 17. Available at http://www.healtheffects.org

146 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.

147 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.

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

epidemiological literature. Int J Cancer 118: 2920-9.
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function) and reproductive outcomes (e.g., preterm birth, low birth 

weight).149,150,151,152

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.153,154,155,156 Long-term exposures in near-road environments have been 

associated with inflammation-associated conditions, such as atherosclerosis and 

asthma.157,158,159 

Several studies suggest that some factors may increase susceptibility to the 

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

respiratory associations in children experiencing chronic social stress, such as in 

violent neighborhoods or in homes with high family stress.160,161,162 

 

149 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.

150 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]

151 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.

152 Wu, J.; Wilhelm, M.; Chung, J.; et al. (2011). Comparing exposure assessment methods for 

traffic-related air pollution in and adverse pregnancy outcome study. Environ Res 111: 685-6692.

153 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

154 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

155 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

156 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]

157 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

158 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

159 McConnell, R.; Islam, T.; Shankardass, K.; et al. (2010). Childhood incident asthma and trafficrelated air pollution at home and school. Environ Health Perspect 1021-1026.

160 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) 
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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 associated ecosystem goods and services. Lastly, visible 

ozone injury to leaves can result in a loss of aesthetic value in areas of special 

 

161 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.

162 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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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.163 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.164

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.165 There are 156 national 

parks, forests and wilderness areas categorized as Mandatory Class I Federal 

areas.166 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, 

 

163 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/

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

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

165 64 FR 35714 (July 1, 1999). 

166 62 FR 38680-38681 (July 18, 1997).
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the most recent data show that these areas continue to suffer from visibility 

impairment. In summary, visibility impairment is experienced throughout the U.S., 

in multi-state regions, urban areas, and remote mandatory class I federal areas.

c. Atmospheric Deposition

Wet and dry deposition of ambient particulate matter delivers a complex 

mixture of metals (e.g., mercury, zinc, lead, nickel, aluminum, cadmium), organic 

compounds (e.g., polycyclic organic matter, dioxins, furans) and inorganic 

compounds (e.g., nitrate, sulfate) to terrestrial and aquatic ecosystems. The 

chemical form of the compounds deposited depends on a variety of factors 

including ambient conditions (e.g., temperature, humidity, oxidant levels) and the 

sources of the material. Chemical and physical transformations of the compounds 

occur in the atmosphere as well as the media onto which they deposit. These 

transformations in turn influence the fate, bioavailability and potential toxicity of 

these compounds. Atmospheric deposition has been identified as a key component 

of the environmental and human health hazard posed by several pollutants including 

mercury, dioxin and PCBs.167

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 nitrogen-nutrient 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.168,169,170,171,172 

 

167 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. 

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

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

169 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. 

170 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. 

171 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. 

172 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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Atmospheric deposition of nitrogen and sulfur contributes to acidification, 

altering biogeochemistry and affecting animal and plant life in terrestrial and 

aquatic ecosystems across the United States. The sensitivity of terrestrial and 

aquatic ecosystems to acidification from nitrogen and sulfur deposition is 

predominantly governed by geology. Prolonged exposure to excess nitrogen and 

sulfur deposition in sensitive areas acidifies lakes, rivers and soils. Increased 

acidity in surface waters creates inhospitable conditions for biota and affects the 

abundance and nutritional value of preferred prey species, threatening biodiversity

and ecosystem function. Over time, acidifying deposition also removes essential 

nutrients from forest soils, depleting the capacity of soils to neutralize future acid 

loadings and negatively affecting forest sustainability. Major effects include a 

decline in sensitive forest tree species, such as red spruce (Picea rubens) and sugar 

maple (Acer saccharum), and a loss of biodiversity of fishes, zooplankton, and 

macro invertebrates.

In addition to the role nitrogen deposition plays in acidification, nitrogen 

deposition also leads to nutrient enrichment and altered biogeochemical cycling. In 

aquatic systems increased nitrogen can alter species assemblages and cause 

eutrophication. In terrestrial systems nitrogen loading can lead to loss of nitrogen 

sensitive lichen species, decreased biodiversity of grasslands, meadows and other 

sensitive habitats, and increased potential for invasive species. For a broader 

explanation of the topics treated here, refer to the description in Section 6.3.2 of the 

RIA.

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 
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were more substantial for sulfur compounds than for nitrogen compounds. In the 

eastern U.S., where data are most abundant, total sulfur deposition decreased by

about 44 percent between 1990 and 2007, while total nitrogen deposition decreased 

by 25 percent over the same time frame.173 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.174

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.175 In laboratory experiments, a 

wide range of tolerance to VOCs has been observed.176 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.177

 

173 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=list.listByChapter&r=216610. 

174 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=list.listByChapter&r=216610. 

175 U.S. EPA. (1991). Effects of organic chemicals in the atmosphere on terrestrial plants. 

EPA/600/3-91/001. 

176 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. 

177 Cape JN, ID Leith, J Binnie, J Content, M Donkin, M Skewes, DN Price AR Brown, AD Sharpe. 

(2003). Effects of VOCs on herbaceous plants in an open-top chamber experiment. Environ. Pollut. 

124:341-343. 
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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.178,179, 180 

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 closelycoordinated 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 lightand 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 

 

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

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

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

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

180 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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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 non-methane 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 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 
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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. 

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.181 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.182 

 

181 Regulatory Impact Analysis for the Control of Hazardous Air Pollutants from Mobile Sources 

Final Rule, EPA 420-R-07-002, Chapter 6

182 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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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 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 “post-EPAct/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). 
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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, 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.

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)
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 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. 

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.
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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,183 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 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.

 

183 Rao, V. (2001) Fuel Sulfur Effects on Exhaust Emissions: Recommendations for MOBILE6, 

EPA420-R-01-039
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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 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%
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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%

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 
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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.184

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 

standard

15,494 16,370

Reduction from off-road 

equipment due to sulfur 

standard

767 897

Percent reduction in 

onroad SO2 emissions

51% 51%

 

184 U.S. Energy Information Administration (2011), Annual Energy Outlook 2011, DOE/EIA0383(2011)
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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,185 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, 186,187,188 as well as correlations between reductions in tailpipe HC 

emissions and reductions in CH4.

189,190 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, 191 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 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 

 

185 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 

186 Michaels, H. (1998) Emissions of Nitrous Oxide from Highway Mobile Sources, U.S. EPA 

EPA420-R-98-009 

187 Behrentz, et al. (2004), Measurements of nitrous oxide emissions from light-duty motor vehicles: 

a pilot study Atmospheric Environment 4291-4303 

188 Meffert, et. al (2000) Analysis of Nitrous Oxide Emissions from Light Duty Passenger Cars, SAE 

2000-01-1952

189 Meszler, D. (2004), Light Duty Vehicle Methane and Nitrous Oxide Emissions: Greenhouse Gas 

Impacts Study for Northeast States Center for a Clean Air Future

190 Graham, L. Greenhouse Gas Emissions from 1997-2005 Model Year Light Duty Vehicles 

Environment Canada ERMD Report #04-44 

191 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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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.

192

 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 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 

 

192 Keller, P. (February, 2013). New Source Review Permitting Impact Analysis for Proposed Tier 3 

Gasoline Program. Memorandum to the docket.
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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 populationweighted 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) 
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counties 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 
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least 21 counties, with a projected population of over 31 million people, would have 

projected design values above the level of the 24-hour standard of 35 μg/m3.193

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/m3on 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/m3

decrease 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 

 

193 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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future-year 24-hour PM2.5 design values are projected to decrease by 0.20 μg/m3

due 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.

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, 

population-weighted -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 standardd

14 28,624,758 

-0.11

Counties whose 2030 control case is 

violating the annual PM2.5 standard, 

population-weightedd-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.

d Eight of these counties are in California, see Table 7-35 in the DRIA. 
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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 standardd

21 31,002,272

-0.50

Counties whose 2030 control case is violating the 

2006 24-hour PM2.5 standard, population-weightedd

-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.

d Eleven of these counties are in California, see Table 7-37 in the DRIA.

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
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> -50 to ≤ -25 0.1%

> -25 to ≤ -10 2.8% 0.7% 56.8%

> -10 to ≤ -5 23.7% 36.8% 30.8%

> -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.194 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 

 

194 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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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. 

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.195

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.196,197,198,199 Household-level 

 

195 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

196 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]

197 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]

198 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.

199 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]
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stressors such as parental smoking and relationship stress also may increase 

susceptibility to the adverse effects of air pollution.200,201

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 202,203,204,205,206,207

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 

 

200 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]

201 Rosa, M.J.; Jung, K.H.; Perzanowski, M.S.; Kelvin, E.A.; Darling, K.W.; Camann, D.E.; 

Chillrud, S.N.; Whyatt, R.M.; Kinney, P.L.; Perera, F.P.; Miller, R.L (2010) Prenatal exposure to 

polycyclic aromatic hydrocarbons, environmental tobacco smoke and asthma. Respir Med (In 

press). doi:10.1016/j.rmed.2010.11.022 [Online at http://dx.doi.org]

202 Marshall, J.D. (2008) Environmental inequality: air pollution exposures in California’s South 

Coast Air Basin.

203 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]

204 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]

205 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]

206 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]

207 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.
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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.”208 

We analyzed whether there were differences between houses and householders in 

such locations and those not in them.209 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.210 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.211 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 reduced-price 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 economically-based exposures.

 

208 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.

209 Bailey, C. (2011) Demographic and Social Patterns in Housing Units Near Large Highways and 

other Transportation Sources. Memorandum to docket.

210 http://nces.ed.gov/ccd/

211 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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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. 

Extensive data from existing Tier 2 (and California LEV II) vehicles show 

the opportunity for further reductions, especially in addressing emissions produced 

at start-up, emissions under high-speed, high-load conditions, the effects of sulfur in 

gasoline, the effects of increased oil consumption, and the effects of 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 heavy-duty 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). 
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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 lightand heavy-duty vehicles throughout this preamble, we describe how the provisions 

would be consistent with the California Air Resources Board (CARB) LEV III 

program. 212 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/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 costeffective 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 heavyduty 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. 

 

212 LEV III program as approved by the California Air Resources Board, January 2012
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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 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.

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 fleetaverage 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 
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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.213,214

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 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 

 

213 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.

214 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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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. 

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.215 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, 

 

215 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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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 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 sales-weighted 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.
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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. 

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.216

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 fleetaverage NMOG+NOX standards for each model year, one for LDVs and LDT1s and 

 

216 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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a second fleet-average standard for all other LDTs (LDT2s, LDT3s, and LDT4s) 

and for MDPVs. We are proposing that the fleet-average 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.

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 
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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.217

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 (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 coldstart 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 wellperforming Tier 2 vehicles. Unlike the NMOG+NOX FTP standard, the PM 

 

217 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-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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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. 

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 light-duty vehicle sales meet the new 

PM standards in MY 2017. 

Because of the expected time and expense of performing emission tests on 

the improved PM test procedures, we are proposing to limit the number of tests 
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using the new procedures that a manufacturer would need to perform at certification 

and during in-use 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).218 

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 low- and 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.219 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.

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

 

218 Durability groups are a subset of engine families. Several engine families may have the same 

durability group.

219 California Air Resources Board (CARB) Initial Statement of Reasons, Public Hearing to 

Consider LEV III, , December 7, 2011
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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 inuse) 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 phase-in 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 phasein 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 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. 
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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 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 
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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 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, 
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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 for all light-duty vehicles.

As is the case for the proposed FTP PM standards, we are proposing a single 

per-vehicle 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 phase-ins. EPA requests comment on this alternative phase-in 

approach as well as on the primary US06 phase-in option above.

All of the proposed SFTP/US06 standards are shown in Table IV-4 and 

Table IV-5. 
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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 
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and SFTP NMOG+NOX standards for the California market will likely represent 

steps toward compliance with this proposed national program. Similarly, 

manufacturers are already 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.220 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. 

 

220 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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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 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 in vehicle mass if manufacturers 

explore lighter exhaust manifold materials in order to reduce thermal mass and 

promote earlier catalyst light-off or add 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 
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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. 

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.

221

 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 

 

221 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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“compliance margin” and is a result of manufacturers’ efforts to address all the 

sources of variability, including: 

 Test-to-test variability (within one test site and lab-to-lab)

 Build variation expectations

 Manufacturing tolerances and stack-up

 Vehicle operation (for example: driving habits, ambient temperature, 

etc.)

 Fuel composition

 The effects of fuel sulfur on exhaust catalysts and oxygen sensors 

 The effects of other fuel components, including ethanol and gasoline 

additives

 Oil consumption

 The impact of oil additives and oil ash on exhaust catalysts and oxygen 

sensors

For MY 2009, 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.222 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 

 

222 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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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 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 
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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 

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 
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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 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. 
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Catalyst PGM loading, when implemented in conjunction with low 

sulfur gasoline, will effectively eliminate NOX emissions under warmedup 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.

 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 fullsize sport utility vehicles (SUVs) in the LDT3 and LDT4 categories) would be the 

most challenging light-duty 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 lightduty 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 

Compliance223

 
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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 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.224,225,226,227,228,229,230,231,232,233 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.

 

223 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.

224 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.

225 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.

226 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.

227 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.

228 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.

229 Takei, Y., Kungasa, Y., Okada, M., Tanaka, T. Fujimoto, Y. (2000). Fuel Property Requirement 

for Advanced Technology Engines. SAE Technical Paper 2000-01-2019.

230 Takei, Y., Kungasa, Y., Okada, M., Tanaka, T. Fujimoto, Y. (2001). “Fuel properties for 

advanced engines.” Automotive Engineering International 109 12, 117-120.

231 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.

232 Shen, Y., Shuai, S., Wang, J. Xiao, J. (2008). Effects of Gasoline Fuel Properties on Engine 

Performance. SAE Technical Paper 2008-01-0628.

233 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.
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 112 of 903

Sulfur from gasoline is oxidized during spark-ignition engine combustion 

primarily to SO2 and, to a much lesser extent, SO3

-2

. Sulfur oxides selectively 

chemically bind (chemisorb) with, and in some cases react with, active sites and 

coating materials within the catalyst, thus inhibiting the intended catalytic reactions. 

Sulfur oxides inhibit pollutant catalysis chiefly by selective poisoning of active 

PGM, ceria sites, and alumina washcoatings (see Figure IV-2).234 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. 

 

234 Heck, R.M., Farrauto, R.J. (2002). Chapter 5: Catalyst Deactivation in Catalytic Air Pollution 

Control, 2nd Edition. John Wiley and Sons, Inc.
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Page 113 of 903

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 2002.234
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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.235,236,237,238 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.239 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).240,241 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 closedcoupled 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. 242

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.243

This may be a significant mechanism for the observed storage of sulfur compounds 

 

235 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.

236 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.

237 Heck, R.M., Farrauto, R.J. (2002). Chapter 6: Automotive Catalyst in Catalytic Air Pollution 

Control, 2nd Edition. John Wiley and Sons, Inc.

238 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.

239 Heck, R.M., Farrauto, R.J. (2002). Chapter 6: Automotive Catalyst in Catalytic Air Pollution 

Control, 2nd Edition. John Wiley and Sons, Inc.

240 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.

241 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.

242 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.

243 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.
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 115 of 903

at light and moderate load operation with subsequent, rapid release as sulfate 

particulate matter when high-load, high-temperature conditions are encountered.244

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.245 Furthermore, regular 

operation at these temperatures and at rich air-to-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.246 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 

 

244 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. 

245 See Chapter 1 of the RIA (Section 1.2.3.2) for more details on this study and its results.

246 Tier 2 Regulatory Impact Analysis (EPA 420-R-99-023, December 22, 1999), available at 

http://epa.gov/tier2/finalrule.htm#regs.
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Page 116 of 903

draft RIA provides details of the Mobile Source Air Toxics (MSAT) Study.

247

 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.248 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, 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 inuse 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 

 

247 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.

248 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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Page 117 of 903

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)

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% 5.4% 7.3% 4.6% 11.1% –
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Page 118 of 903

(0.0896) (0.0118) (0.0023) (0.0465) (<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, 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 cleanout 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. 
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Page 119 of 903

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 MSAT and Umicore studies mentioned above. For 

further details regarding the Tier 2 In-Use Gasoline Sulfur Effects Study, see the

draft report on this work.249

c. 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 

 

249U.S. EPA. 2013. "The Effects of Fuel Sulfur Level on Emissions from Tier 2 Vehicles In-Use." 

EPA-420-D-13-003. Available in the docket for this rule. 
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Page 120 of 903

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.250

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 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 higher-sulfur 

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-

 

250 Heck, R.M., Farrauto, R.J. (2002). Chapter 6: Automotive Catalyst in Catalytic Air Pollution 

Control, 2nd Edition. John Wiley and Sons, Inc.
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Page 121 of 903

back FTP tests using 33 ppm sulfur gasoline.251 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.252 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.253,254 

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.

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.) 

 

251 Heck, R.M., Farrauto, R.J. (2002). Chapter 6: Automotive Catalyst in Catalytic Air Pollution 

Control, 2nd Edition. John Wiley and Sons, Inc.

252 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.

253 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.

254 Shapiro, E. (2009). National Clean Gasoline – An Investigation of Costs and Benefits. Published 

by the Alliance of Automobile Manufacturers.
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Page 122 of 903

d. 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.

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.255 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. 

 

255 The LEV III program as approved by the California Air Resources Board, January 2012.
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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 

requirement256 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) 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 

 

256 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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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.257 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 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 light-duty fleet) we are proposing a 

150,000 mile, 15 year useful life value. For the lighter vehicles, we are proposing 

 

257 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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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.258 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 pollutants259 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.) 

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 

 

258 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.

259 PM, CO, and HCHO
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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 

fuels260 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.261 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.262 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. 

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 

 

260 This includes fuels used for low temperature and high altitude testing and durability requirements. 

See Section IV.D below. 

261 Diesel fueled and alternative fueled vehicles would continue to test on the fuels used under the 

Tier 2 program. 

262 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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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.263 

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 nearzero 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.264 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. 

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 

 

263 That is, a manufacturer that certifies a vehicle to LEV III in MY 2015 and MY 2016. 

264 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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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 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. 
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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. 

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 
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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 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. 
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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 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 
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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 phasein would be acceptable. 

EPA requests comment on the proposed PM phase-in schedules.
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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 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 
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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 inuse standard apply to all 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 lowlevel 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 
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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.

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.265 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 

 

265 EPA is incorporating the CARB DOR methodology by reference. 
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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.

266

 Because of the significant liability that 

manufacturers would be accepting, we do not expect that the use of this credit 

opportunity would be widespread. However, based on our modeling of the 

expected deterioration of the emissions of future Tier 3 vehicles absent 

repair/replacement of failed emission controls, we anticipate that the value to the 

environment of long emissions warranties in terms of reduced real-world emissions 

would significantly exceed the 5 mg/mi NMOG+NOX credit.267

We propose to use the same criteria for approving such a credit as does the 

parallel California program.268 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 any implications for record 

retention requirements by manufacturers.

 

266 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.

267 Beardsley, M, et al. (2013, February). Updates to MOVES for the Tier 3 NPRM. Memorandum 

to the docket.

268 EPA is incorporating the CARB extended emission warranty provisions by reference.
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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.

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. We 

seek comment on this approach to compliance demonstration. 

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.269 

 

269

 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).
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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.270 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 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.

 

270 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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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 light-duty 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 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.
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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.

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
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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 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.
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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 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
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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 costeffective, 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.

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.271 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 

 

271 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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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. 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-of-sales 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 
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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 lightduty 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 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 
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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 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 phasein requirements. A manufacturer that exceeded the phase-in requirements in any
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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 noninterim 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,272 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 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 

 

272 66 FR 5002 (January 18, 2001).
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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 realworld 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 “not-to-exceed” provisions to control off-cycle 

emissions. Therefore, in addition to the SFTP provisions, we are further limiting 

enrichment on spark ignition engines in all areas of operation unless absolutely

necessary.

a. SFTP NMOG+NOX, PM and CO Standards

The 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

Class 3:

FTP Bins 270, 400, 570 550 7 6.0

FTP Bins 200, 230 350 7 4.0
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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 

weighted-composite cycle, and we are proposing to retain this approach for lightduty 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 emissions test.273 Although our SFTP 

 

273 Letter from Robert H. Cross, California Air Resources Board, to Dawn Friest, EMA, dated March 

2, 2011.
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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 Class 3 

HDVs. The set of composite SFTP cycles we are proposing is fully consistent with 

the MDV LEV III program.
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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 light-duty Tier 3 approach, the California LEV III 
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program for MDVs, and EPA programs for controlling GHG emissions from lightand heavy-duty vehicles.

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.
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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 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. 
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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

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.274 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 

 

274 76 FR 57106 (September 15, 2011).
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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 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-toweight 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 
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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 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.
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 Engine Control Calibration Changes – These include changes to retard 

spark and/or adjust air/fuel mixtures such that more combustion heat is 

created during the cold start on gasoline engines. Diesel engines may

use unique injection timing strategies or other available engine control 

parameters. Engine calibration changes can affect NMOG, NOX and PM 

emissions.

 Thermal Management – This technology includes all design attributes 

meant to conduct the combustion heat into the catalyst with minimal 

cooling on both gasoline and diesel engines. This includes insulating the 

exhaust piping between the engine and the catalyst, reducing the wetted 

area of the exhaust path and/or reducing the thermal mass of the exhaust 

system. Close-coupling of catalysts (packaging the catalysts as close to 

the head of the engine as possible to mitigate the cooling effects of 

longer exhaust piping) can also be effective, but is more difficult to 

employ than in light-duty applications because of durability concerns 

with highly loaded operation and the potential increase in fuel 

consumption to protect the catalyst from high temperatures.

 Catalyst PGM Loading – Additional 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 
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feasibility of this longer useful life based on experience with it in the PZEV element 

of the ZEV mandate.275

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 percent-of-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 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 

 

275 “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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GHG standards on the chassis test.276 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 low-emissions 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.

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 

 

276 76 FR 57106 (September 15, 2011).
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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.

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 
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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,277 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

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).278,279 For ease of reference these four categories 

 

277 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. 

278 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). 
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may be referred to as PZEV evap, LEV III evap, Tier 3 evap, and Tier 2 evap in this 

section.280

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.

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 

 

279 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.

280

 “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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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.

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
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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. 

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
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LDT < 6,000 lbs GVWR 0.50

0

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.281 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 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 

 

281 EPA is proposing to incorporate by reference the CARB Option 1 test procedures and emission 

standards for this interim period. 
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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.282 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 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 

 

282 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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certification fuel and test procedures and meet Tier 3 evaporative emission 

standards.283

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 programs under 

 

283 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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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 

phase-in 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 
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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; 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 
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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 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 phase-in requirement of 60 percent or 60,000 vehicles. 

For the primary phase-in option the manufacturer could use part or all of its 

allowances in 2018. 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 
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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.

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 overcomplying 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 
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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. 

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 
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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 evaporative emission 

standards.

284

 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.285 Manufacturers would be allowed to use credits only within a 

 

284 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). 

285 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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defined averaging set. The averaging sets are: (1) LDVs and LDT1s, (2) LDT2s, 

(3) LDT3s, LDT4s, and MDPVs, and (4) HDGVs. These sales-weighted calculated 

values 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 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, 
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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 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 
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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.286 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 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.).

 

286 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 

(non-California, non-section 177 states).
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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 

2015-2017 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 

2007.287 These newest standards apply only to testing under low-altitude 

conditions.288 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 

 

287 72 FR 8428 (February 26, 2007).

288 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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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 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 
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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 phasein beginning in the 1998 MY. Almost universally manufacturers elected to 

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 
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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.

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.
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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 fuelsystem 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 low-cost solution that is easily assembled and works for the 

demanding performance needs 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 
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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 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 
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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 microcracks 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 in-use 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 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. 
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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.289 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.290 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.

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 

 

289 MDPVs also meet the definition of HDVs, but they are classified separately for evaporative and 

refueling emission purposes. See 40 CFR 86.1803-01.

290 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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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 
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daily average reduction in vehicle refueling emissions for this class of vehicles is 

large relative to the reduction in evaporative emissions expected under Tier 3. 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 inuse 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. 
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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 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 
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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.). 

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 1993.291 Those changes included: (1) diurnal testing based on heating 

and cooling the ambient air in the SHED292 instead of forcing fuel temperatures 

through a specified temperature excursion; (2) repeated 24-hour diurnal 

measurements to capture both permeation and diurnal emissions; (3) hightemperature hot soak testing; (4) high-temperature running-loss measurements with 

a separate standard, including controlled fuel temperatures according to a fueltemperature 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. 

 

291 58 FR 16002 (March 24, 1993).

292 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.
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After adopting these evaporative test procedures, we set new standards for 

refueling emissions control which called for onboard refueling vapor recovery

(ORVR).293 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. 

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.

 

293 59 FR 16262 (April 6, 1994). 
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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 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 
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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 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. Fuelrelated 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 
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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 E15.294 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.

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 

 

294

 Moulis, C. (2012, January). SHED FID Responses for Ethanol. Memorandum to the docket. 
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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.

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 
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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 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 
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(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 

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 
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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. 

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)295 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.296 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 

 

295 64 FR 23906 (May 4, 1999).

296 65 FR 59922-59924 (October 6, 2000).
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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 

in-use LDVs and LDTs certified to meet the enhanced evaporative emission 

standards implemented for 1996 and later model years297 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.298 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 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 

 

297 58 FR 16002 (March 24, 1993).

298 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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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 inuse 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.299 The CDPHE continued to collect the 

same type of data in different locations in the Denver area for the next two 

summers.

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.300 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.301 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 

 

299 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, 

300 DeFries, T; Palacios, C., Kishan, S. (2012), Estimated Summer Hot Soak Distributions for the 

Denver’s Ken Caryl IM Station Fleet.

301 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.
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emission rate that would be expected from a leak of 0.020 inches which is the 

detection standard for OBD II systems.

302

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 problem.303,304 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.

 

302 Compare the first 15 minutes of hot soak data from the field studies with implanted leaks in E-77-

2 studies.

303 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.

304 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 LightDuty Vehicles.
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To better understand this issue EPA has examined evaporative emission 

system DTC and monitor ready information from I/M programs from Texas and 

California.305 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.

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.306

In summary, information gathered from evaporative emissions testing 

conducted in the IUVP program indicates that relatively low mileage/ newer 

 

305 Fulper, C. (2013, February). Preliminary Analysis of OBD Evaporative System Information from 

I/M Stations - California and Texas, Memorandum to the docket.

306 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. 
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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.

307

 

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. 

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 

in-use, 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 

 

307 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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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.308 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 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.

 

308 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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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 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. 
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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 pre-certification 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.309 In this case, tests from both points combined must pass the proposed 

emission standard.

The procedure would be conducted as follows:

 Calibrate the testing apparatus and otherwise verify testing apparatus is 

ready and able to complete the procedure 

 Seal fuel system so as to pressure test entire system (purge valve, cap, 

etc.) 

 

309 For related information see “IM240 & Evap Technical Guidance”, EPA 420-R-00-007, April, 

2000. 
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 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.

310

 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 approach deemed equivalent or better. 

 

310 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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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).311

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,312 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 

 

311 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.

312 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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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 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 in-use 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.313 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.314 

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.

 

313 We are not proposing to change the requirement for incompletes and vehicles with a GVWR 

above 14,000 lbs. 

314 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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 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 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 
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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 

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 
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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 standards. 315 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). 

 

315 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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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 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 
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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 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 
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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

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 OBDbased 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 
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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 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. 
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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 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. 
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 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.

 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 
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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.316 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 in-use 

operating pressure in excess of 0.36 psi (10 inches water). As a means to 

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 pre-established 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”

 

316 Passavant, G. (February 2013). Presentation on Evaporative Emission System Leaks for a Fuel 

Tank Under Pressure. Memorandum to the docket.
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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. 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 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.317 The revised test fuel specifications would 

apply for exhaust emissions testing, fuel economy/greenhouse gas 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.318

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 

 

317 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.

318As 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.
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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.319 Below is an overview of some 

of the key changes. A summary of the proposed test fuel specifications is provided 

in Table IV-21. 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 

forward-looking 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.320 While E15 is only commercially available at a 

limited number of fuel retailers, EPA believes it could become a major 

 

319 The LEV III program as approved by the California Air Resources Board, January 2012

320 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).
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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 premiumrequired321 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. 

 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. 

 

321 Premium-required defined at §1065.710(d).
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 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.322 

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.323 

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. 

 Olefins - adjusting the olefins specification to better match today’s inuse 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 

 

322 72 FR 8434 (February 26, 2007).

323 For more information on current aromatics levels, refer to Chapter 3 of the draft RIA.
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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)

D86-10a

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 Milliliter 2.0 Maximum

Total Aromatic 

Hydrocarbons vol. % 19.5-24.5

C6 Aromatics (benzene) vol. % 0.6-0.8 D5769-10

C7 Aromatics (toluene) vol. % 4.4-5.5
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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 forwardlooking 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 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. 
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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.

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 
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older light-duty motor vehicles, all heavy-duty gasoline vehicles and engines, 

motorcycles, and all gasoline-powered nonroad products (which includes boats).324 

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 highoctane, high-ethanol gasoline, all EPA confirmatory and in-use testing would also 

be conducted on high-octane, high-ethanol gasoline. This could help manufacturers 

who wish to raise compression ratios to improve vehicle efficiency as a step toward 

complying with the 2017 and later light-duty greenhouse gas and CAFE standards. 

This in turn could help provide a market incentive to increase ethanol use beyond 

E10 and enhance the environmental performance of ethanol as a transportation fuel 

by using it to enable more fuel efficient engines. We seek comment on the 

appropriateness of the alternative test fuel provisions at §1065.701(c) and the need 

 

324 76 FR 44406 (July 25, 2011).
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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.325 

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 sparkignition 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 

 

325 ASTM International D5798-11, “Standard Specification for Ethanol Fuel Blends for FlexibleFuel Automotive Spark-Ignition Engines”.
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that denatured fuel ethanol (DFE) that meets the proposed specifications would be 

used to increase the ethanol content to 80 to 83 volume percent.326 

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.327 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 percent

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 

 

326 The proposed requirements for DFE are contained in Section V.C of today’s preamble.

327 The specifications for commercial grade butane are contained in 40 CFR 80.82.
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to have an RVP of 10 psi to maintain the level of performance established under the 

Tier 2 program. 

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 medium-duty passenger vehicles.328 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. 

 

328 77 FR 62623 (October 15, 2012).
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The first round of standards by EPA and NHTSA under the National Program cover 

MY 2012-2016.329

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-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.330 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. 

 

329 75 FR 25324 (May 7, 2010).

330 49 U.S.C. 32904(c).
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Because ethanol has a lower energy content than gasoline, i.e., fewer British 

thermal units (Btus) or joules per gallon,331 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 equivalent to what would have been determined 

using the 1975 baseline test fuel.332 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.333 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.

334

 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 

 

331 EPA estimates that, on average, E85 fuel contains 25-30 percent less energy per gallon than 

gasoline with zero ethanol.

332 40 CFR 600.113-12(h)(1).

333 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.

334 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.
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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, 2004335)). 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 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 

 

335 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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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 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.
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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 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 
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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 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 
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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. 

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 
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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 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.
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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-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 phase-in requirements for exhaust and evaporative emissions. All hardship 

requests would be subject to EPA review and approval. Appeals for such hardship 
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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 

criterion 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. 

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 lightduty 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 
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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.336 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 enginebased 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.

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.

 

336 See 77 FR 62793-62794 and 40 CFR 86.1838-01(d)
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 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 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
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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 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.
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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 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 
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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.337 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 one-hour 

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 specifications and we are making efforts to 

adopt a single, national regulatory program, we believe this is an 

appropriate step. This proposal includes heavy-duty 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 

 

337 See 40 CFR 86.106-96(a) and Enclosure 2 to EPA Guidance letter CCD-02-04, February 6, 2002.
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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 cycle, if performed as part 

of the initial measured tests would serve as the cleanout procedure and therefore no 
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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 V.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 Program338 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 lowemission 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 

 

338 67 FR 6698 (February 10, 2000).
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the emissions control 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 twothirds 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 
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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 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 pergallon 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 
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results from our refinery-by-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 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.339 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 inuse 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.340 Beijing, 

China also recently introduced a 10-ppm sulfur limit for gasoline.341 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 

 

339 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.

340 Hart Energy Consulting. (2011). International Fuel Quality Center: 2011 Worldwide Fuel 

Specifications 

341 Article from China.org.cn entitled “Beijing to implement stricter fuel standards”, May 19, 2012, 

retrieved from http://www.china.org.cn/environment/2012-05/19/content_25422404.htm
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coming from their FCC unit (i.e., postreating)342, 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-byrefinery 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 heavy

FCC naphtha into the distillate pool).

343

 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-to-batch 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. 

 

342 Some of them may also have an FCC pretreater.

343 Our in-house refinery modeling considers 111 operational refineries producing non-California 

gasoline. 
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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, 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 
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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.344 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 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 

 

344 Together, the streams from the reformer and isomerization units account for approximately onethird of gasoline. 
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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 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. 
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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.345 Thus, assuming no trading between companies is a conservative 

assumption and the real impact is likely to be somewhere in 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 

 

345 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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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. 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 pre-and 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.
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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 three-years 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 
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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 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 
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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 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 non-small, 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 be even 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
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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 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.346 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

 

346 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. AM00-57.
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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 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 
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Page 263 of 903

pipelines. Further, gasoline goes through the same pipelines and terminals back-toback 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 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.347 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 

 

347 This approach is reflected in the draft regulatory text.
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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-purchaserconsumer 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.348 As discussed in Section V.A.2.b, 

our analysis of the potential 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.349 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 

 

348 Alliance of Automobile Manufacturers (2011, October 6). Letter to EPA Administrator, Lisa 

Jackson.

349 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.
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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.350 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 gasoline and jet fuel components in the transmix.351 

Transmix processors do not handle sufficient volumes to support the installation of 

currently available desulfurization units.352 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 

 

350 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. 

351 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.

352 Transmix processors produce ~0.1 percent of the gasoline consumed in the U.S.
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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 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.353 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 

 

353 40 CFR 79.2(d)(1)
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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 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 energyefficient 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. 
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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.354 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 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 pollutantspecific 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 

 

354 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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pollutant.355 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,356

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.357 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 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 NSR358, 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 

 

355 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.

356 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.

357 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.

358 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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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 project-affected units to further limit the emissions increase, and/or 

because the refinery “nets out” all or part of the emissions increase. 

However, we 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., 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 
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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.359 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.

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.

 

359 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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 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 

program360, 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 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 

 

360 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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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 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 
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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.361 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 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 

 

361 67 FR 80186 (December 31, 2002).
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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.362 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.363 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 2012.364 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.365 In December 2012 we revised the primary annual PM2.5 NAAQS and 

designations associated with that revised standard are expected to become effective 

in 2015.366 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 

 

362 75 FR 31514 (June 3, 2010).

363 77 FR 41051 (July 12, 2012).

364 77 FR 30088 (May 21, 2012)

365 Listings of areas currently designated nonattainment for all the NAAQS are available at 

http://www.epa.gov/oar/oaqps/greenbk/index.html.

366 78 FR 3086 (January 15, 2013). 
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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.

367

 In addition, in 2010 we supplemented this rule with additional provisions 

for the PSD program specifically.

368

 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.

369

 

EPA has completed the initial round of mandatory designations for the 1-hour NO2

NAAQS and all areas have been designated unclassifiable/attainment.370 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 

 

367 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.

368 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.

369 75 FR 6474 (February 9, 2010) and 75 FR 35520 (June 22, 2010).

370 77 FR 9532 (February 17, 2012).
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respect to the pre-existing NAAQS for NO2 and 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.371 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.372 

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 

refinery-specific 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 

 

371 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. 

372 Keller, P. (February 2013). New Source Review Permitting Impact Analysis for Proposed Tier 3 

Gasoline Program. Memorandum to the docket.
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most profitable to generate 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.373 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-

 

373 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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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 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 likelihood that 

refineries’ costs for equipment and process technology for compliance with Tier 3 

would include any associated costs of compliance with NSR.

In 2010, EPA issued a white paper on available and emerging technologies 

for reducing GHGs from the petroleum refining industry.

374

 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 

 

374 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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plants, and sulfur recovery units. The identified GHG control technologies for 

these types of units predominately involve opportunities for energy efficiency. 

Consistent with the findings reported in the white paper, our experience to date with 

GHG permitting at refineries and other similar sources supports the application of 

energy efficient design and operation of affected units 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.375 These standards are referred to as MACT 1 and 2 and were 

 

375 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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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. 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.376 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.377 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 web-based resources on GHG permitting. These 

GHG permitting resources include various materials on the topic of BACT for 

 

376 76 FR 15451 (March 21, 2011) and 78 FR 7138 (January 31, 2013).

377 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.
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GHG, including white papers and copies of our comments on recent draft permits 

proposed by state and local permitting agencies.378 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 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 

 

378 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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rulemaking. We also note that “netting out” of NSR could be a complex and often 

time-consuming 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 time-saving 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 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.379 

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.380 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.381 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 

 

379 40 CFR 80.385(e).

380 California Code of Regulations, Title 13, Section 2262.9, “Requirements Regarding Denatured 

Ethanol Intended For Use as a Blend Component in California Gasoline”. 

381 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 SparkIgnition Engine Fuel” requires that the maximum denaturant concentration in DFE is 5 volume 

percent. 
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primarily because of logistical difficulties in segregating ethanol destined for 

California from other destinations.382 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.383 

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.384 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 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.

385

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 

 

382 RFA publication entitled “Fuel Ethanol, Industry Guidelines, Specifications and Procedures,” 

2011.

383 For example, Aventine Renewable Energy Fuel-Grade Ethanol specifications at 

http://www.aventinerei.com/pdfs/fuel_grade_spec.pdf

384 ASTM International D4806-11(a), “Standard Specification for Denatured Ethanol for Blending 

with Gasolines for Use as Automotive Spark-Ignition Engine Fuel”. 

385 See the definition of Renewable Fuel in 40 CFR 80.1401.
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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 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 
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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.386 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)387 (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 ethanol. We have also developed a possible approach, along with 

draft regulations, that are included in the docket on which we specifically seek 

comment.388 

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.389 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 

 

386 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. 

387 73 FR 22277, 22281 (April 25, 2008).

388 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.

389 ASTM International D5798-11, “Standard Specification for Flexible-Fuel Automotive SparkIgnition Engines”.
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gasoline (CG)) are used to manufacture E51-83.390 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 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.391 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.392

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 

 

390 Letter to Robert Sydney, Division of Energy Resources, Boston, MA, from James Caldwell, U.S. 

EPA, February 15, 2006. 

391 ASTM International D4806-11(a), “Standard Specification for Denatured Ethanol for Blending 

with Gasolines for Use as Automotive Spark-Ignition Engine Fuel”.

392 In August of 2011 the retail price of E85 was approximately 60 cents per gallon more than 

gasoline on an energy content adjusted basis.
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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.393 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.394 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 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 

 

393 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.

394 40 CFR 79.56(e)(1)(i).
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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. 

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 
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anywhere from 2 to almost 30 ppm.395 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.396 Currently, downstream 

blenders are exempt from these regulations because the certification and 

compliance burden is being borne by the upstream refiners.397 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 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 

 

395 Report on Ethanol Producers Survey, Presented at the California Phase 3 Reformulated Gasoline 

Regulation Workshop, June 15, 2000, Carl Reeder, Archer Daniels Midland

396 40 CFR 80.330, 80.335, 80.365, and 80.370.

397 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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10-ppm standard on a volume-weighted 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 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 
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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 in-use are running on 10 ppm average fuel. 

Otherwise, it is possible that the greater ease of generating early credits relative to 

30 ppm sulfur (as opposed to 10 ppm in 2017 and beyond) 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 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 
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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 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 
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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 begin as early as possible; achieving the air 

quality benefits of the program as soon as possible, while helping to ensure that 
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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.
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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, 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 pergallon 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 
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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.

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 per-gallon 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 non-small, though relief would be granted on a case-by-case basis 
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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.

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 longterm 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 
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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: (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.398 Some of these streamlining measures, if adopted, may also impact 

the Tier 3 sulfur compliance provisions proposed below. 

 

398 For more information on Part 80 regulatory streamlining options, refer to Section VI.
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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.

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. 
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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 sulfurbased 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. 

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 
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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 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.
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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.

 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 
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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.399 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 preexisting 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. 

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:

 

399 See, for example, 69 FR 39051 (June 29, 2004).
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 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.

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 
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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 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 nonexempt gasoline, identification of the exempt gasoline on PTDs, and pump labeling.

c. Gasoline for Export

Gasoline produced for export, and that is actually exported for use in a 

foreign country, 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).
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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 million people currently live in counties exceeding a 

NAAQS.400 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.401 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 

 

400 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-HQOAR-2011-0135.

401 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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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 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 
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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 

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-to-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 
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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 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.
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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 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 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.

Section 211(c)(2)(B) requires that, prior to adopting a fuel control based on 

a significant impairment to vehicle emission-control systems, EPA consider 

available scientific and economic data, including a cost benefit analysis comparing 

emission-control devices or systems which are or will be in general use that require 

the proposed fuel control with such devices or systems which are or will be in 

general use that do not require the proposed fuel control. As described below, we 
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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 adopting the controls for gasoline apply as 

well to adopt the controls for DFE, other oxygenates, butane, and gasoline

additives.
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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. 

A. 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 Section VI.A.1.a.iii).

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.402 Currently, there are 17 complex model parameters on the RFG/antidumping 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 

 

402 61 FR 17230 (March 29, 2001).
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actually included in the gasoline batch must be tested and reported on an everybatch basis (except for refiners that are still subject to a complex model toxics 

standard; they must test all parameters but may use monthly composite testing and 

reporting except for sulfur and benzene, and oxygenate, where applicable). 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 AntiDumping 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 
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single electronic format that would collect all required data and maximize the 

capability of electronic reporting with data reuse, no duplicate fields, and a userfriendly interface.

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).

iii.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 
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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 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”
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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”

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, tertiaryAmyl 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 
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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)”

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”

iv. 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.
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v. 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 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.403 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.

vi. 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, 

 

403 70 FR 74561 (December 15, 2005).
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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).

vii. 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.

viii. 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.

ix. 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.404 Several major gasoline marketers have adopted Top 

 

404 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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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 include gasoline volatility (RVP), reformulated gasoline and antidumping, 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 
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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”).

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 
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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 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 requirements405) 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

 

405 See §§80.580, 80.584 and 80.585.
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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

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,406

oxygenate content,407 olefin content,408 and sulfur content409 as well as sulfur in 

butane410. 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 

 

406 ASTM D 1319-03ε1 (see §80.46(f)(3)).

407 ASTM D 4815-04 (see §80.46(g)(2)).

408 ASTM D 6550-05 (see §80.46(b)(2)(i)).

409 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)). 

410 ASTM D 4468-85 (reapproved 2000) and ASTM D 3246-96 (see §§80.46(a)(4)(i) and 

80.46(a)(4)(ii)).
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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)411 is almost consistent with the PBMS policy and with the National 

Technology Transfer and Advancement Act (NTTAA).412 For example, in the 

nonroad diesel rulemaking, which controlled the sulfur content of diesel fuel,413

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 particular designated and alternative methods for 15 ppm 

diesel sulfur.414 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.415 The 

second option was to meet performance based requirements similar to those adopted 

for 15 ppm diesel sulfur.416 We are proposing today to extend the performancebased 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 precision417 and accuracy418 of chosen fuel parameter 

 

411 ASTM International (ASTM) is one such organization.

412 Public Law 104-113, 104th Congress, March 7, 1996, H.R. 2196.

413 69 FR 38958, June 29, 2004. This rulemaking used standard materials with known chemical 

composition to evaluate the accuracy of candidate test methods.

414 See §§80.584 and 80.545.

415 See §80.580(c)(2).

416 See §§80.584(a)(2), 80.584(b)(2)(i) through 80.584(b)(2)(iii), and 80.585.

417 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 
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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,419 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 in-line 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.

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 standards420 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 

 

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.

418 Accuracy – the closeness of a single measurement to its true value of what is being measured.

419

 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.

420 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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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 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 
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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 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.
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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 operator421 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 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.

 

421 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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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 deviation422 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 thenallowed 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 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 ppm423. 

 

422 Where the standard deviation is estimated from a sample of the population (formula uses “N-1” in 

the denominator).

423 This number was determined by using the repeatability equation for “r” from ASTM D7039-07 

for a 10 ppm sulfur gasoline to get 1.76 ppm, dividing the “r” in ppm by 2.77 to obtain the 

underlying standard deviation of 1.39 ppm, and multiplying the result by 1.5 (criterion used in diesel 

sulfur rule) to get 0.95 ppm.
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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)424

because the previous primary test method, D3246-11, had become somewhat 

obsolete. Given that D3246-11 is no longer widely available,425 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, 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 

 

424 71 FR 16492 (April 3, 2006).

425 See EPA-HQ-OAR-2005-0048-0002.
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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.426

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 sets out our proposed precision criteria for the various method-defined fuel 

parameters with no alternative test method. 

 

426 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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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 

Criterion427

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

Aromatics in diesel fuel Diesel sample containing 35 0.70 volume percent

 

427 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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volume percent aromatics

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 interlaboratory crosscheck program for at least five months prior to application.428

 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 labspecific 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.429 The 

 

428 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.

429 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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purposes of Section 12(d) of Public Law 104-113 are: (1) To direct “federal 

agencies to focus upon increasing their use of [voluntary consensus] standards430

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.”431 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.”432

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 

 

430 This use of the word “standards” refers to test methods, calibration materials, etc.

431 See Cong. Rec. H1262 (daily ed. February 27, 1996)(statements of Rep. Morella).

432 63 FR 8546 (February 19, 1998).
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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).

(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 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 
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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, 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 
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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 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.A.3.g.i and 

VI.A.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. 
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(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 methoddefined 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 explained earlier, that rule imposed a maximum value for the 

standard deviation433 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.434 We 

are also proposing that laboratories would specifically compute the difference 

between the instrument's average measurement of the fuel closest to the applicable 

 

433 Where the standard deviation is estimated from a sample of the population (formula uses “N-1” in 

the denominator).

434 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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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 inter-laboratory 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 long-established 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. 

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 requirements435) 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 

 

435 See §§80.580, 80.584 and 80.585.
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proposing today, would likely suffice to homogenize and improve measurement 

quality in these already-stable 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. 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.436

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 

 

436 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.
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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 VCSBbased 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.437 

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 

method-defined 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.A.3.d.ii and VI.A.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.

Second, the Agency proposes that the candidate non-VCSB test method be 

tested on a range of fuels438 and by a qualified reference installation of the 

applicable designated test method.

Third, the Agency proposes that the specific laboratory using the candidate 

non-VCSB 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.

 

437 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.

438 Fuels, either consensus named fuels or locally named reference materials, used must be typical of 

those to be analyzed by the facility in practice and must meet the data requirements (variability, etc.) 

of ASTM D6708-08.
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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 matrixsensitive 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 reproducibility439 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 interlaboratory 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 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 

 

439 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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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 each instrument used to make measurements for 
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reporting or recordkeeping purposes.440 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”) material441

either of: once per 20 production tests or once per week and maintain both an “I” 

chart442 and an “MR” chart443. 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 D6299-10e1 for 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-be-depleted, 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 

 

440 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.

441 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.

442 See ASTM D6299-10e1, section 7 and Section A1.5.1 for chart construction and usage, including 

criteria for deciding upon corrective action.

443 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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soon-to-be-depleted old QC material. The results would be plotted from the “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.444

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,445 construct “MR” and “I” charts446 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 material447 once every 20 production tests or 

once per week whichever is more frequent. We are also proposing the maintenance 

of an “I” chart448 and a “MR” chart449. 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 

 

444 See ASTM D6299-10e1, Annex A1.9 Q-Procedure. Procedures differ depending whether an Ichart, MR chart, EWMA chart, Q-chart or a combination of these charts are utilized by the 

laboratory.

445 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.

446 See ASTM D6299-10e1, Section 8.4 and appropriate Annex sections for chart construction and 

guidance.

447 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.

448 See ASTM D6299-10e1, section 7 and Section A1.5.1 for chart construction and usage, including 

criteria for deciding upon corrective action.

449 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 D6299-10e1for making

the transition from one batch of QC material to the next.

With regard to accuracy we are proposing that each laboratory perform a 

check standard450 for each instrument as defined in ASTM D6299-10e1 for each 

instrument on a quarterly basis. We propose that check standards for “methoddefined” 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 methods451 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 occasions452, 

construct “MR” and “I” charts453 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” material454 once per 20 production tests or once per week, whichever is more 

 

450 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.

451 Following the guidelines of ASTM D6299-10e1, Section 6.2.2.

452 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.

453 See ASTM D6299-10e1, Section 8.4 and appropriate Annex sections for chart construction and 

guidance.

454 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.
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frequent. We are also proposing the maintenance of an “I” chart455 and a “MR” 

chart456. 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 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 methoddefined 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 

 

455 See ASTM D6299-10e1, section 7 and Section A1.5.1 for chart construction and usage, including 

criteria for deciding upon corrective action.

456 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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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 

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 performancebased 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.457 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 

 

457 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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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 discussed, and must have published the information 

necessary to correlate the alternative test method to the designated test method.458

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 parameter459 and for determining whether the alternative 

test method can be adequately correlated with the designated test method.460 

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 

 

458 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.

459 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.

460 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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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 

method-defined 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 newlyimposed 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 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 
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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 percent pure and has the following properties: sulfur <= 30 ppm, benzene <= 

0.03 volume percent, olefins <= 1.0 volume percent, and aromatics <= 2.0 volume 

percent. Documents from the supplier demonstrating the butane is “noncommercial 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 percent, 

olefins <= 10.0 volume percent, and aromatics <= 2.0 volume percent. 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. 

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 
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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, 2011.461 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. 

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.462 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 

 

461 76 FR 39478 (July 6, 2011). 

462 http://www.arb.ca.gov/regact/2012/zev2012/fro2rev.pdf
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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.

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.
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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”).463 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 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 

 

463 58 FR 58382 ( November 1, 1993)
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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 not-to-exceed test procedures. These provisions are unique to heavyduty 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 heavyduty vehicles above 14,000 lbs GVWR to demonstrate compliance with evaporative 

emission standards. Most of these provisions are identical to those that apply under 

40 CFR part 86, subpart B. This can better be accomplished with appropriate 

references to the 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. 
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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 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.
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4. Updating Reference Procedures

The regulations in 40 CFR part 1065 depend on a large number of reference 

procedures and technical standards from ASTM, SAE International, and ISO, 

among others. These reference procedures and technical standards are updated 

periodically to keep them current with ongoing developments in the field. Many

times these changes include only minor corrections or clarifications. In other cases 

the updates incorporate new test methods, accommodate changing engine 

technologies, or other more substantive changes. Whether the updated reference 

documents involve major changes or not, it is important for the regulations to rely

on documents that are readily available. Toward that end, we 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 costeffectiveness estimates to 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 
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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.

 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 
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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 
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associated with both of these changes. Table VII-3 below describes both the cost of 

the technologies as well as their anticipated application rates.

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 
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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 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 purgeassist 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 heavy-duty 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 
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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 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 a

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

a 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 heavyduty 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 
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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)a

Year

Exhaust Evap Facilities

Light-duty 2b/3 All Light-duty 2b/3 All All Total

2016 $0 $0 $0 $0 $0 $0 $22.5 $22.5

2017 $634 $0 $634 $71.4 $0 $71.4 $3.75 $709

2018 $1,150 $23.1 $1,170 $167 $3.86 $171 $3.75 $1,340

2019 $1,240 $28.6 $1,270 $159 $3.76 $162 $3.75 $1,440

2020 $1,350 $34.2 $1,380 $216 $5.22 $221 $3.75 $1,600

2021 $1,470 $40.0 $1,510 $208 $5.09 $213 $3.75 $1,730

2022 $1,580 $46.5 $1,630 $264 $6.52 $271 $3.75 $1,900

2023 $1,610 $44.8 $1,660 $253 $6.27 $259 $3.75 $1,920

2024 $1,720 $44.8 $1,770 $257 $6.38 $263 $3.75 $2,040

2025 $1,830 $44.9 $1,870 $246 $6.12 $253 $3.75 $2,130

2030 $1,750 $46.5 $1,790 $246 $6.74 $253 $3.75 $2,050

2040 $1,750 $51.9 $1,800 $246 $7.52 $254 $3.75 $2,060

2050 $1,750 $58.6 $1,810 $246 $8.49 $255 $3.75 $2,070

NPV, 3% $29,900 $814 $30,700 $4,250 $116 $4,360 $89.1 $35,100

NPV, 7% $14,700 $384 $15,100 $2,090 $55.0 $2,150 $52.2 $17,300

a 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 

Section 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
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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. 

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 10 ppm. 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 
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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.

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. 
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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.

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.464

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 

 

464 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.
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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.465 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. 466 When the FCC cracks this 

heavy, sour feedstock, a portion of the sulfur in the feed to the FCC ends up in the 

FCC naphtha, an important gasoline blendstock stream.467 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 

 

465 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. 

466 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.

467 On average, the fluidized catalytic cracker supplies about 35 percent of a refiner’s gasoline 

output.
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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 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 
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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. 

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 pergallon 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

40

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

b

er ofrefin

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 
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Page 377 of 903

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 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 intracompany trading analysis for the proposal. However, in reality, we expect that 

some inter-company 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 

intra-company 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
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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 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 pergallon costs for complying with the sulfur control standard under an ABT program 

with intra-company credit transfers. 
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0

5

10

15

20

25

30

35

40

45

50

-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 

intra-company 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

10

20

30

40

50

60

70

80

90

100

5 10 12.5 15 17.5 20 22.5 25 27.5 30 32.5 35 37.5 40 42.5

N

u

m

b

er ofrefin

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). 468 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.

469

 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 

 

468 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. 

469 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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desulfurization cost under Tier 3 would also be the same refineries which sets the 

gasoline price in the gasoline market today. 

Although API did not provide an average gasoline desulfurization cost in its 

report, we could calculate an average cost based on the gasoline volume and total 

annual costs provided. The total cost reported in the report for the 10 ppm average 

gasoline sulfur standard is $2390MM/yr and the non-California gasoline volume is 

7343 thousand barrels per day. This results in an average per-gallon desulfurization 

cost of $0.89/bbl or 2.12 c/gal. The difference between the average cost and 

marginal cost (price increase) that API is projecting is profit. Thus, API’s analysis 

would suggest that the oil industry 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 
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the Haverly refinery cost model that we use,470 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 perbarrel 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.

 

470 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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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 standard and also evaluated the ICCT and API cost studies.471 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$ a

Year Vehicle Exhaust 

Emission Control 

Costs

Vehicle Evaporative 

Emission Control 

Costs

Facility Costs 

($Million)

Fuel Sulfur 

Control Costs

($Million)

Total 

Proposed 

Program Costs 

 

471 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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($Million) ($Million) ($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

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

a 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 a

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

a 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 population-weighted annual average PM2.5 is 0.05 μg/m3in 

2030). The decrease in population-weighted 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).472

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),473,474 we 

 

472 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 population-weighted PM2.5 and ozone design value metrics presented in Chapter 7, which 

represent the average for areas with a current air quality monitor.

473 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.
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estimate that by 2030, implementation of the proposed standards would reduce 

approximately 970 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)475,476 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.

477

 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 

 

474 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.

475 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.

476 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.

477 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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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 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 peerreviewed studies of air quality and human health effects.478,479

 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,480 the final Portland Cement National Emissions 

Standards for Hazardous Air Pollutants (NESHAP) RIA,481 the final 2014-2018 MY 

Heavy-Duty Vehicle Rule,

482 and the final 2017-2025 MY Light-Duty Vehicle 

 

478 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

479 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

480 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

481 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

482 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 
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Rule.483 To model the ozone and PM air quality impacts of the proposed standards, 

we used the Community Multiscale Air 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).484 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.485 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

Total: $9.6 - $20

PM: $7.0 - $17

 

and Air Quality, EPA-420-R-11-901, August, 2011. Available on the Internet at 

http://www.epa.gov/oms/climate/documents/420r11901.pdf.

483 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

484 Information on BenMAP, including downloads of the software, can be found at 

http://www.epa.gov/ttn/ecas/ benmodels.html.

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

http://www.epa.gov/PM/2012/finalrule.pdf
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Ozone: $2.7 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 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 SixCities 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
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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

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.
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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 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 National-Scale 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 subchronic health effects.486

 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,487 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.”488 EPA 

continues to work to address these limitations; however, we did not have the 

 

486 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.

487 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>.

488 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/EP

A-COUNCIL-08-001-unsigned.pdf>.
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methods and tools available for national-scale application in time for the analysis of 

the proposed standards.489 

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 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)

 

489 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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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)

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).490

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

170

(73 – 260)

250

(120 – 380)

260

(110 – 410)

540

(300 – 780)

 

490 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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 Ito et al. (2005) – Non-accidental

 Levy et al. (2005) – All cause

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)

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 ozone-related 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 95TH

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 
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(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

($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
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($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.

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 

concentration-response 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.
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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 including a probabilistic representation of 

causality were explored in the expert elicitation-based results of the PM 

NAAQS RIA.491 

 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 ozone-related mortality should be included in estimates of the 

health benefits of reducing ozone exposure.492 EPA has requested 

advice from the National Academy of Sciences on how best to quantify 

 

491 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

492 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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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. EPA addressed many of 

these comments in the analysis of the final PM NAAQS.493,494 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 

 

493 National Research Council (NRC). (2002). Estimating the Public Health Benefits of Proposed Air 

Pollution Regulations. The National Academies Press: Washington, D.C.

494 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.
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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.495

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.

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

 

495 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-perton 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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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. 

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,496

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 

 

496 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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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 

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 
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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 fleetaverage 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 acknowledge that there is a need for continuing PM measurement 

method development prior to implementing this standard.497 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 costprohibitive 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.

 

497 California Air Resources Board (CARB) Initial Statement of Reasons, Public Hearing to 

Consider LEV III, December 7, 2011
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We also considered an even lower sulfur standard of 5 ppm. Based upon the 

results of our test programs and associated modeling, a sulfur standard of 5 ppm 

could reduce VOC+NOX emissions from the existing fleet by an additional 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 ppmgallon basis. Additionally, as explained earlier, a 5 ppm standard would likely result 

in the elimination of the ability for 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 

per-gallon 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. 
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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 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.498 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 

 

498 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 fullcost pass-through using data from 1984-1994. Using full-cost pass-through overstates costs and thus 

contributes to lower vehicle sales than using a lower estimate. To the extent that the auto industry 

has become more competitive over time, full-cost pass-through may be more appropriate than a 

result based on this older study.
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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 pass-through is not necessary: firms may choose to reduce impacts on 

sales by not passing along full costs. In 2004, the Federal Trade Commission 

reported that “concentration for most levels of the petroleum industry has remained 

low to moderate.”499 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. 

 

499 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 .
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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.500 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. 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.501 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.”

 

500 77 FR 62623 (October 15, 2012).

501 Schmalensee, R., & Stavins, R. (2011). A Guide to Economic and Policy Analysis of EPA’s 

Transport Rule” White paper commissioned by Excelon Corporation ().
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We follow the theoretical structure proposed in a study by Morgenstern, 

Pizer, and Shih (2002)502 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. 

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 $1 million (1987$).

 

502 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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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),503 which provides direct estimates of the employment 

per $1 million in sales of goods in 202 sectors. The values considered here are for 

Motor Vehicle Manufacturing (NAICS 3361) and Motor Vehicle Parts 

Manufacturing (NAICS 3363). 

The Census Bureau provides both the Annual Survey of Manufactures504

(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-

 

503 Bureau of Labor Statistics. Employment Requirements Matrix. 

http://www.bls.gov/emp/ep_data_emp_requirements.htm

504 U.S. Census Bureau. Annual Survey of Manufactures. 

http://www.census.gov/manufacturing/asm/index.html
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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 factorshift 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 0.667.505 

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.

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 light-duty 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.

 

505 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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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 job-years

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 labor-intensive 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 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 
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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.

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 
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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.

506

 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.

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 

 

506 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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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 has announced 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.
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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 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 
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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 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 set-up. 

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.
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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.

This proposed rule contains reporting and recordkeeping requirement within 

the context of EPA’s motor vehicle certification program and the manufacturers’ inuse 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 highmileage 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, producers of gasoline 

additives, and producers of denatured fuel ethanol and other oxygenates. The 

proposed recordkeeping and reporting requirements for refiners and importers of 

motor vehicle gasoline are the same requirements that exist under the Tier 2 sulfur 

program.507 The recordkeeping and Product Transfer Document (PTD) 

requirements for gasoline additive producers and PTD retention 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 2,675, the total burden hours to be 

84,000 and the total cost to respondents to be $6,300,000.

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 

 

507 65 FR 6698, February 10, 2000; OMB Control Number: 2060-0437; EPA ICR 1907.05
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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.

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 
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small governmental jurisdiction that is a government of a city, county, town, school 

district or special district with a population of less than 50,000; and (3) a small 

organization that is any not-for-profit enterprise which is independently owned and 

operated and is not dominant in its field.

The following table provides an overview of the primary SBA small 

business categories potentially affected by this regulation:

Industry NAICSa 

Code (2007)

Defined as small entity by SBA 

if less than or equal to:

Gasoline fuel refiners and 

importers

324110 1,500 employees

Ethanol producers 325193 1,000 employees

Gasoline additive manufacturers 325199, 

325998, 

424690

1,000 employees

500 employees

100 employees

Transmix processors Varied 1,500 employees

Petroleum bulk stations and 

terminals

424710 100 employees

Other warehousing and storagebulk petroleum storage493190 $25.5 million (annual receipts)

Light-duty vehicle and light-duty 

truck manufacturers

336111,

336112

1,000 employees

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 
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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 Rule508 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 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 

 

508 66 FR 5136 (January 18, 2001).
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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 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 
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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 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.
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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 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 
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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 in-use 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 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 
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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.

(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. 
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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 longterm 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 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 
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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.

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 SERrecommended relaxed NMOG+NOX standards over the Federal Test Procedure 
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(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 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.
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(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

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 
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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.

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 
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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 costbenefit 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 costeffective approach to achieve the statutory requirements of the rule. The costs and 

benefits associated with the proposal are 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.
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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.509 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.510

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.511 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 near-roadway 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.

 

509 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.

510 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.

511 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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Section III.C describes the ambient air quality changes resulting from the 

proposed standards, which represent levels to which the general population is 

exposed. Children are not expected to experience greater ambient concentrations of 

air pollutants than the general population. However, because of their greater 

susceptibility to air pollution and their increased time spent outdoors, it is likely that 

the proposed standards would have particular benefits for children’s health.

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.
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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 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 cost-effective for the regulated community; it is also intended to 

encourage innovation in analytical technology and improved data quality. EPA is 

not precluding the use of any method, whether it constitutes a voluntary consensus 

standard or not, as long as it meets the performance criteria specified.

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
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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

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 lowincome 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 
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disproportionately near high-traffic 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.

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
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Administrative practice and procedure, Electric power, Fuel economy, 

Incorporation by reference, Labeling, Reporting and recordkeeping requirements.

40 CFR Parts 1036 and 1037

Administrative practice and procedure, Air pollution control, Confidential 

business information, Environmental protection, 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, 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 
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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:

* * * * *

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.
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* * * * *

(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 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.
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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 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.htm

l. 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.
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(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.

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.
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(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.

(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).
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(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:

* * * * *

(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) * * *
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(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) * * *

(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 
*** E.O. 12866 Review – Revised– Do Not Cite, Quote, or Release During Review ***

Page 449 of 903

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.htm

l. 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 Supercritical-Fluid 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.

(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.
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(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.

(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. 
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(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.

(8) Method-defined fuel parameter means a fuel parameter for which an EPAprescribed primary test method or designated method defines the regulatory standard. 

Examples of method-defined fuel parameters include olefin content in gasoline, Reid 

vapor pressure (RVP) of gasoline, distillation parameters of gasoline, benzene content of 

gasoline, aromatic content of gasoline and diesel fuel, and oxygen/oxygenates content of 

gasoline. 

(9) Reference Installations are designated test method installations that are used to 

qualify the accuracy of other method-defined parameter instruments. Reference 

installations of the designated test method will be used to evaluate the accuracy of other 

method-defined alternative test methods and to establish correlation equations if 

necessary.

(10) Correlation equation is a correction equation as determined by the use of 

ASTM 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. 
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(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 

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.
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(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

(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 
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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.

(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.
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(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 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.
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(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

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.
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(1) Beginning November 30, 2014, the reference installation of the methoddefined 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.

(l) Qualification criteria for Voluntary Consensus Standard Based (VCSB) 

Method-Defined 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 
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a correlation equation needs to be applied that predicts designated test method results 

from the applicable method-defined alternative test method.

(4) The test methods specified at §§80.2(w) and 80.46(a)(1), (a)(2), (b)(1), (c)(1), 

(d)(1), (e)(1), (f)(1), and (g)(1) and in use prior to 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 (nonVCSB) 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 locallynamed reference materials that are typical of those analyzed by the facility in practice 

using good laboratory practices and must meet the data requirements for variability as 

required in ASTM 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.

(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 methoddefined 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 
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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 methoddefined 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.

(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 
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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.

(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 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 
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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 QProcedure 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:

(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 
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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 QProcedure 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 Non-Voluntary 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 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 
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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” 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 special-cause signals, then the result of the new
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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.htm

l. 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).
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c. Removing and reserving paragraph (d)(2)(v)(E).

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.

(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.
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(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.

(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).

* * * * *
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(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.

* * * * *

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).
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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.

(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]
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(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 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.

* * * * *
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(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. 

* * * * *

(k) [Reserved]

(l) Reports for per-gallon compliance gasoline. In the case of reformulated 

gasoline or RBOB for which compliance with each of the standards set forth in §80.41 is 

achieved on a per-gallon basis, the refiner or importer shall submit to the Administrator, 

by March 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:
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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

(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.
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(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.

* * * * *

(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.
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(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).

§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.
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* * * * *

(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).

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

* * * * * 
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(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:

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:

§ 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), 
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(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 
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Unleaded Automotive Spark-Ignition Engine Fuel for Intake Valve Deposit Formation,” 

1994, which is incorporated by reference pursuant to §80.178. 

(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.
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This section specifies the deposit control test requirements and performance 

standards which must be met in order to certify detergent additives for use in unleaded 

gasoline pursuant to §80.161(b)(1)(ii)(A)(2). These standards must be met in the context 

of the specific test procedures identified in paragraphs (a) and (b) of this section. Testing 

must be conducted and the performance standards met when the subject detergent 

additive is mixed in a test fuels meeting all relevant requirements of §80.177. Complete 

test documentation must be submitted by the certifying party within 30 days of receipt of 

a written request from EPA for such records.

(a) Fuel injector deposit control testing. The required test fuel must produce no 

more than one inoperative injector when tested in accordance with the fuel injector 

deposit test procedure specified in paragraph (c) of this section.

(b) Intake valve deposit control testing. The required test fuel must produce the 

accumulation of less than 50 mg of intake valve deposits on average when tested in 

accordance with ASTM D6201 - 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 
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maintained in the range of 68-75°F. The room shall be equipped with an exhaust system 

that connects to the vehicle tail pipe to remove the exhaust gases from the building. It is 

recommended that an interlock be provided so that if the building exhaust system fails, 

the vehicle test will shut down.

(ii) Electrical Power. Two 110-volt, 15-amp circuits are needed (20-amp circuits 

are recommended) to operate the four block heaters and a battery charger.

(iii) Fuel Drain Facility. A facility is required to drain the fuel from the vehicle 

between tests. The fuel is drained from the service port on the fuel rail, near the back of 

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.
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(ii) Block Heaters. Install four electric block heaters, General Motors part number 

12371293, in the coolant passages of the engine block, two on each side of the block. 

The heaters will be plugged into a heater control unit. Two of the heaters will remain on 

at all times during the first 144 hours of the injector fouling test, while the other two 

heaters will be turned on and off by the controller as needed to maintain an engine 

temperature of about 100-102°C during the soak periods of the test. (The temperature 

will drop while the engine is running, as the coolant from the radiator circulates through 

the engine. The temperature should recover to 100-102°C within about 20 minutes after 

the engine shuts off.)

(iii) Thermocouples. Install a 1/16-inch Type K thermocouple in a threaded bolt 

hole on the rear of the right cylinder head. This thermocouple provides the feedback 

signal to the controller to turn two block heaters on and off. Install another thermocouple 

in the other hole near the first thermocouple. This second thermocouple provides a signal 

to an over-temperature safety shut-off on the heater controller. If the engine temperature 

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 hotsoak 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.
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(E) Continuously count and display the number of cycles that have been 

completed throughout the test.

(4) Test Procedure. The steps described in paragraphs (c)(3)(i) though (vi) of this 

section must be performed by the action described in paragraph (c)(3)(vii) of this section 

so that the new injectors are exposed only to the new test fuel.

(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.

(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 
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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).

(1) The test fuel must contain levels of the specified parameters consistent with 

the requirements of this section. 
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(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.

(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). 
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(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.

(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.
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(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. 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 
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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.

* * * * *

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 pergallon sulfur standard of §80.510(c) shall apply to all NRLM diesel fuel beginning 
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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 purchaserconsumers 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 

purchaser-consumer who sells, dispenses, or offers for sale or dispensing, motor vehicle 

diesel fuel subject to the 15 ppm sulfur standard of §80.520(a)(1), must affix the 

following conspicuous and legible label, in block letters of no less than 24-point bold 

type, and printed in a color contrasting with the background, to each pump stand:

ULTRA-LOW SULFUR HIGHWAY DIESEL FUEL (15 ppm Sulfur Maximum)

Required for use in all highway diesel vehicles and engines.

Recommended for use in all diesel vehicles and engines.

* * * * *

25. Section 80.573 is amended by revising paragraph (a) to read as follows:

§ 80.573 What labeling requirements apply to retailers and wholesale purchaserconsumers 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.
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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 purchaserconsumers 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.

(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).
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§ 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.htm

l. 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.

* * * * *

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) * * *
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(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).

(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 
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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.

* * * * *

(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.
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(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).

(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), 
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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 pergallon 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.

b. Revising paragraph (f)(2).

§ 80.1451 What are the reporting requirements under the RFS program?
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(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

Sec.

80.1600 Additional 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.

80.1620 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.

80.1630 Sampling and testing requirements for refiners and importers.

80.1631 Sample retention requirements.

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 exemption.

80.1656 Exemptions for gasoline used for research, development, or testing 

purposes.

80.1657 [Reserved]

80.1658 Requirements for gasoline for use in American Samoa, Guam, and the 

Commonwealth of the Northern Mariana Islands.

80.1659 [Reserved]

80.1660 Prohibited acts.

80.1661 What evidence may be used to determine compliance with the prohibitions 

and requirements of this subpart and liability for violations of this subpart?

80.1662 Liability for violations 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.
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§80.1600 Additional definitions for subpart O.

The definitions of §80.2 and the following additional definitions apply to this 

subpart O:

California gasoline means any gasoline designated by a refiner or importer for use 

in California.

Certified 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 blender has the meaning given at §80.84(a)(7).

Transmix gasoline product (TGP) has the meaning given at §80.84(a)(3).

Transmix processing facility has the meaning given at §80.84(a)(4).

Transmix processor has the meaning given at §80.84(a)(5).

§80.1601 Fuels subject to the provisions of this subpart.

(a) For the purposes of this subpart, the following fuels are subject to the 

standards and requirements of this subpart:
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(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. 

(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 shall continue to apply until the gasoline produced or imported by any refiner or 

importer is required to comply with the standards and requirements under this subpart O.

§80.1603 Gasoline sulfur standards for refiners and importers.
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(a) Sulfur standards. (1) Annual average standard. (i) The refinery or importer 

annual average gasoline sulfur standard is 10.00 parts per million (ppm) or milligrams per 

kilogram (mg/kg), except as provided in paragraph (a)(1)(iii) of this section.

(ii) The averaging period is a calendar year (January 1 through December 31).

(iii) The refinery or importer annual average gasoline sulfur standard is the 

maximum average sulfur level allowed for gasoline produced at a refinery or imported by

an importer during each calendar year beginning January 1, 2017, except as provided by 

the following:

(A) The credit use provisions of §80.1616.

(B) Beginning January 1, 2020, for small refiners and small volume refineries 

approved pursuant to the provisions of §80.1622. Small refiners and small volume 

refineries will continue to be subject to the provisions of subpart H 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.

Si = The sulfur content of batch i determined under §80.1630, in ppm (mg/kg).
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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) Oxygenate added downstream from the refinery or import facility. A refiner 

or importer may include oxygenate added downstream from the refinery or import facility

when calculating the sulfur content, 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 paragraph (a)(2) of this section 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) Exclusions. 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 SulfurFRGAS.

(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.

(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 
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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 
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testing (using the methods in §80.1630) that the TGP meets the applicable sulfur 

standards under §80.1604(b), prior to the TGP leaving the transmix processing facility.

(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.

(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.
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(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).

(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). 
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§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) Batch numbers. Every batch of oxygenate produced or imported at oxygenate 

production or import facility shall be assigned a number (the “batch number”), consisting 

of the EPA-assigned oxygenate producer or importer registration number, the EPA 

facility registration number, the last two digits of the year in which the batch was 

produced, and a unique number for the batch, beginning with the number one for the first 

batch produced or imported each calendar year and each subsequent batch during the 

calendar year being assigned the next sequential number ( e.g. , 4321–54321–95–000001, 

4321–543321–95–000002, etc.)

§§80.1611—80.1612 [Reserved]
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§80.1613 Standards and other requirements for gasoline additive manufacturers 

and blenders.

Gasoline additive manufacturers and blenders must meet the following requirements:

(a) Gasoline additive manufacturers, as defined in 40 CFR 79.2(f), must meet the 

following requirements: 

(1)(i) Except as otherwise provided, this section applies to any additive, as 

defined in 40 CFR 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).

(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 40 

CFR 79.2(d), and is subject to all the provisions that apply to refiners under this subpart 

O.
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§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 ppmgallons, for use pursuant to subpart H of this part.

(ii) No credits shall be generated unless the value of ECa is positive.

(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 
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subpart H of this part. 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 ppmgallons, 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 ppmgallons, 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.

(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.

§80.1616 Credit use and transfer.

(a) Credit use.
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(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 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.

(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.
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(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:

(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.
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(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 occurs, the refiner shall notify EPA in writing no 

later than 20 days following the disqualifying event.

(2) Except as provided under paragraph (f)(3) of this section, any refiner whose 

status changes under this paragraph (f) shall meet the applicable standards of §80.1603 

within a period of up to 30 months from the disqualifying event for any of its refineries 

that were previously subject to the small refiner standards of §80.1623.

(3) A refiner may apply to EPA for up to an additional six months to comply with 

the standards of §80.1603 if more than 30 months would be required for the necessary

engineering, permitting, construction, and start-up work to be completed. Such 

applications must include detailed technical information supporting the need for 

additional time. EPA will base a decision to approve additional time on information 

provided by the refiner and on other relevant information.

(4) Disqualification under this paragraph (f) of this section shall not apply in the 

case of a merger between two previously approved small refiners.

(5) If a refiner receives a delay per paragraphs (f)(2) and/or (f)(3) of this section, 

the refiner may not generate gasoline sulfur credits under this subpart O during that 30 or 

36 month period.
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(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.

(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.
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(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.

(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 EIA, 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 
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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) of this 

section, as applicable, 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.

(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. 
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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:

(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.
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(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.

(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.
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(c) The hardship extension application must contain a letter signed by the 

president or the chief operating officer or chief executive officer of the company, or 

his/her designee, stating that the information contained in the application is true to the 

best of his/her knowledge.

(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 

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 

computer-controlled in-line blending equipment is exempt from the requirement of 

paragraph (a)(1) of this section to obtain the test results required under paragraph (a)(1) 

of this section prior to the gasoline leaving the refinery, provided that the refiner obtains 

an exemption from this requirement from EPA. To obtain such exemption, the refiner 

must:

(A) Have been granted an in-line blending exemption under §80.65(f)(4); or

(B) If the refiner has not been granted an exemption under §80.65(f)(4), submit to 

EPA all of the information required under §80.65(f)(4)(i)(A). A letter signed by the 

president, chief operating officer or chief executive officer of the company, or his/her 

designee, stating that the information contained in the submission is true to the best of 

his/her belief must accompany any submission under this paragraph (a)(3)(i)(B).

(ii) Refiners who seek an exemption under paragraph (a)(3)(i) of this section must 

comply with any EPA request for additional information or any other requirements that 

EPA includes as part of the exemption.

(iii) Within 60 days of EPA’s receipt of a submission under paragraph (a)(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)(3)(ii) of this 
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section. In the absence of such notification from EPA, the effective date of an exemption 

under paragraph (a)(3)(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)(3)(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 

§80.8.

(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
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(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.

(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.
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(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 (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 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:
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(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.

(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 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 
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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.

(g) Certified Sulfur-FRGAS. This section does not apply to Certified SulfurFRGAS.

(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 §§80.1652 and 

80.1653, except as provided in paragraph (h)(2) of this section.

(2) An importer who elects to comply with the alternative standards in paragraph 

(a)(2) of this section must certify in the annual report whether it is in compliance with the 

applicable per-gallon batch standard set forth in paragraph (a)(2) of this section, in lieu of 

providing the information required by §80.1652 regarding annual average sulfur content 

and compliance with the average standard under §80.1603.

(i) Effect of noncompliance. If any of the requirements of this section are not 

met, all gasoline imported by the truck importer during the time any requirements are not 

met is deemed in violation of the gasoline sulfur average and per-gallon cap standards in 

§80.1603. Additionally, if any requirement is not met, EPA may notify the importer of 

the violation and, if the requirement is not fulfilled within 10 days of notification, the 

truck importer may not in the future use the sampling and testing provisions in this 

section in lieu of the provisions in §80.1630.

§§80.1642-§80.1649 [Reserved]

§80.1650 Registration. 
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The following registration requirements apply under this subpart:

(a) Registration with the EPA Administrator is required for any:

(1) Gasoline refiner or importer having any refinery or import facility subject to 

the gasoline sulfur standards under this subpart O.

(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.

(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.
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(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.

(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.

(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.
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(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”.

(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 purchaserconsumer 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. 
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(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 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 decimal places.

(5) The annual average sulfur level after inclusion of any credits, reported to two 

decimal places.

(6) Separately provided information for credits, and separately by year of 

creation, as follows:

(i) The number of credits at the beginning of the averaging period, reported to the 

nearest whole number.

(ii) The number of credits generated, reported to the nearest whole number.

(iii) The number of credits used, reported to the nearest whole number.

(iv) If any credits were obtained from or transferred to other parties; and for each 

other party, its name and EPA refiner or importer registration number, and the number of 

credits obtained from or transferred to the other party.

(v) The number of credits that expired at the end of the averaging period, reported 

to the nearest whole number.

(vi) The number of credits that will carry over into the subsequent averaging 

period, reported to the nearest whole number.

(7) For each batch of gasoline produced or imported during the averaging period, 

all 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 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.
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(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 SulfurFRGAS imported from each foreign refiner and refinery, reported to one 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.

(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 (whichever is earlier), 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.
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(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:

(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.

(3) The calculations used to determine compliance with the applicable sulfur 

average standards of §80.1603 or §80.1604.
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(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 is 

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 five years from the 

date the credits are transferred; and shall be kept by the transferee for five years from the 

date the credits were transferred, used, or terminated, whichever is later.

(2) Early credits.

(i) Where the party generating the credits does not transfer the credits, records 

must be kept for five years from the date of creation, use, or termination, whichever is 

later.

(ii) Where early credits are transferred, records relating to such credits shall be 

kept by the transferor for five years from the date the credits are transferred; and shall be 

kept by the transferee for five years from the date the credits were transferred, used, or 

terminated, whichever is later.
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(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.

(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.
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(c) Use of California test methods and offsite sampling procedures. In the case of 

any gasoline that is not California gasoline and that is either produced at a refinery

located in the State of California or is imported from outside the United States into the 

State of California, the refiner or importer may, with regard to such gasoline:

(1) Use the sampling and testing methods approved in Title 13 of the California 

Code of Regulations instead of the sampling and testing methods required under 

§80.1630; and

(2) Determine the sulfur content of gasoline at offsite tankage (which would 

otherwise be prohibited under §80.65(e)(1)).

(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.

(ii) [Reserved]

§80.1655 National security exemption.

(a) The standards of §80.1603 do not apply to gasoline that is produced, imported, 

sold, offered for sale, supplied, offered for supply, stored, dispensed, or transported for 

use in any of the following:

(1) Tactical military vehicles, engines, or equipment having an EPA national 

security exemption from the gasoline emission standards under 40 CFR part 86.

(2) Tactical military vehicles, engines, or equipment that are not subject to a 

national security exemption from vehicle or engine emissions standards as described in 

paragraph (a)(1) of this section but, for national security purposes (for purposes of 

readiness for deployment 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.
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(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.

(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.
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(4) With regard to control, a demonstration that the program affords EPA a 

monitoring capability, including all the following:

(i) A description of the technical and operational aspects of the program.

(ii) The site(s) of the program (including facility name, street address, city, 

county, state, and zip code).

(iii) The manner in which information on the fuel used in the program (including 

quantity, fuel properties, name, address, telephone number and contact person of the 

supplier, and the date received from the supplier), will be recorded and made available to 

the Administrator upon request.

(iv) The manner in which the party will ensure that the research and development 

fuel will be segregated from gasoline meeting the standards of this subpart and how fuel 

pumps will be labeled to ensure proper use of the research and development fuel.

(v) The name, address, telephone number, and title of the person(s) in the 

organization requesting an exemption from whom further information on the application 

may be obtained.

(vi) The name, address, telephone number, and title of the person(s) in the 

organization requesting an exemption who is responsible for recording and making 

available the information specified in this paragraph (c), and the location where such 

information will be maintained.

(d) Additional requirements.

(1) The product transfer documents associated with research and development 

gasoline must comply with requirements of §80.1651(c).

(2) The research and development gasoline must be designated by the refiner or 

supplier, as applicable, as exempt research and development gasoline.

(3) The research and development gasoline must be kept segregated from nonexempt gasoline at all points in the distribution system.

(4) The research and development gasoline must not be sold, distributed, offered 

for sale or distribution, dispensed, supplied, offered for supply, transported to or from, or 

stored by a fuel retail outlet, or by a wholesale purchaser-consumer facility, unless the 

wholesale purchaser-consumer facility is associated with the research and development 

program that uses the gasoline.

(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 
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applicant and the Administrator (or delegate), which may include such terms and 

conditions as the Administrator determines necessary to monitor the exemption and to 

carry out the purposes of this section, including restoration of emission control systems.

(1) The volume of fuel subject to the approval shall not exceed the estimated 

amount under paragraph (c)(3) of this section, unless EPA grants a greater amount in 

writing.

(2) Any exemption granted under this section will expire at the completion of the 

test program or three years from the date of approval, whichever occurs first, and may

only be extended upon re-application consistent will all requirements of this section.

(3) EPA may elect at any time to review the information contained in the request, 

and where appropriate may notify the responsible person of disapproval of the 

exemption.

(4) In granting an exemption the Administrator may include terms and conditions, 

including replacement of emission control devices or elements of design, that the 

Administrator determines are necessary for monitoring the exemption and for assuring 

that the purposes of this subpart are met.

(5) Any violation of a term or condition of the exemption, or of any requirement 

of this section, will cause the exemption to be void ab initio.

(6) If any information required under paragraph (c) of this section should change 

after approval of the exemption, the responsible person must notify EPA in writing 

immediately. Failure to do so may result in disapproval of the exemption or may make it 

void ab initio, and may make the party liable for a violation of this subpart O.

(f) Effects of exemption. Gasoline that is subject to a research and development 

exemption under this section is exempt from other provisions of this subpart O provided 

that the fuel is used in a manner that complies with the purpose of the program under 

paragraph (c) of this section and all other requirements of this section.

(g) Notification of completion. The party shall notify EPA in writing within 30 

days after completion of the research and development program.

(h) Submission. Requests for research and development exemptions shall be sent 

to 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]
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§80.1658 Requirements for gasoline for use in American Samoa, Guam, and the 

Commonwealth of the Northern Mariana Islands.

The gasoline sulfur standards of this subpart O do not apply to gasoline that is produced, 

imported, sold, offered for sale, supplied, offered for supply, stored, dispensed, or 

transported for use in the Territories of Guam, American Samoa or the Commonwealth of 

the Northern Mariana Islands, provided that such gasoline meets all 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:

(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.
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(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. 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 §§80.47 and 

80.1630. Any evidence or information, including the exclusive use of such evidence or 

information, may be used to establish the sulfur level of gasoline 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 §§80.47 and 

80.1630, business records, and commercial documents.

(b) Determinations of compliance with the requirements of this subpart other than 

the sulfur standards, and determinations of liability for any violation of this subpart, may

be based on information obtained from any source or location. Such information may

include, but is not limited to, business records and commercial documents.
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§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.

(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.
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(12) Parent corporation liability. Any parent corporation is liable for any 

violations of this subpart that are committed by any of its wholly-owned subsidiaries.

(13) Joint venture and joint owner liability. Each partner to a joint venture, or 

each owner of a facility owned by two or more owners, is jointly and severally liable for 

any violation of this subpart that occurs at the joint venture facility or facility owned by

the joint owners, or is committed by the joint venture operation or any of the joint owners 

of the facility.

(b) Persons liable for failure to meet other provisions of this subpart. Any person 

who:

(1) Fails to comply with a provision of this subpart not addressed in paragraph (a) 

of this section is liable for a violation of that provision.

(2) Causes another person to fail to meet a requirement of this subpart not 

addressed in paragraph (a) of this section, is liable for causing a violation of that 

provision.

§80.1663 Defenses for a violation of a prohibited act 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 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.
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(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) 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 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]
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§80.1665 Penalties.

(a) Any person liable for a violation under §80.1662 is subject to civil penalties as 

specified in section 205 of the Clean Air Act (42 U.S.C. 7524) for every day of each such 

violation and the amount of economic benefit or savings resulting from each violation.

(b) Any person liable under §80.1662(a)(1) or (a)(2) for a violation of the 

applicable sulfur averaging standard or causing another party to violate that standard 

during any averaging period, is subject to a separate day of violation for each and every

day in the averaging period. Any person liable under §80.1662(a)(11) or (b) for a failure 

to fulfill any requirement for credit generation, transfer, use, banking, or deficit 

correction, is subject to a separate day of violation for each and every day in the 

averaging period in which invalid credits are generated or used.

(c)(1) Any person liable under §80.1662(a)(3) through (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 non-complying 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 this paragraph (c), 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 subpart H of this part, or this 

subpart O; instead, the importer of any foreign-produced gasoline shall be responsible for 

compliance with the standards and requirements of this subpart O that relate to importers. 
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(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 

Sulfur-FRGAS.

(b) Petition for approval of small refiner or small volume refinery status. To be 

approved for small refiner status or small volume refinery status a foreign refiner must 

submit a petition for approval as provided under §80.1622 and this section. If small 

refiner status or small volume refinery status is approved, the foreign refiner may produce 

gasoline for export to the United States, during the period starting January 1, 2017 and 

ending December 31, 2019, that is subject to the sulfur content standards of subpart H of 

this part at §80.195 that were applicable to refiners from 2006 through 2016. A foreign 

refiner is not eligible to generate sulfur credits under subpart H of this part or this subpart 

O, as this occurs through the importer. 

(c) General requirements for foreign refiners approved as small refiners or small 

volume refinery status. A foreign refiner of a refinery that has been approved as a small 

refiner refinery or a small volume refinery must designate all gasoline produced at the 

foreign refinery that is exported to the United States as either Certified Sulfur-FRGAS or 

as Non-Certified Sulfur-FRGAS, except as provided in paragraph (c)(3) of this section. 

(1) In the case of Certified Sulfur-FRGAS, the foreign refiner must meet the 

sulfur standards of subpart H of this part as described in paragraph (b) of this section and 

the requirements of this section.
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(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 NonCertified Sulfur-FRGAS for the names “reformulated gasoline” or “RBOB” wherever 

they appear in the following provisions:

(i) The designation requirements in this section.

(ii) The recordkeeping requirements under §80.1653.

(iii) The reporting requirements in §80.1652 and this section.

(iv) The product transfer document requirements in §80.1651 and this section.

(v) The prohibitions in §80.1660 and this section.

(vi) The independent audit requirements under §80.415 and paragraph (h) of this 

section; and the attest engagement provisions of §§80.125 through 80.127, §80.128(a), 

(b), (c), and (g) through (i), and §80.130.

(3)(i) Any foreign refiner that has been approved as a small refiner or whose 

refinery has been approved as a small volume refinery under this subpart O may elect to 

classify no gasoline imported into the United States as Sulfur-FRGAS, provided the 

foreign refiner notifies EPA of the election no later than November 1 of the prior 

calendar year. 

(ii) An election under paragraph (c)(3)(i) of this section shall meet all 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.

(2) On each occasion when any person transfers custody or title to any SulfurFRGAS prior to its being imported into the United States, it must include all the 

following information as part of the product transfer document information in this 

section:

(i) Identification of the gasoline as Certified Sulfur-FRGAS or as Non-Certified 

Sulfur-FRGAS.

(ii) The name and EPA refinery registration number of the refinery where the 

Sulfur-FRGAS 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 
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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 

Sulfur-FRGAS.

(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 

Sulfur-FRGAS.

(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

(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.
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(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 

Sulfur-FRGAS 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.

(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
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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, meeting 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 ASTM.

(ii) The United States importer and the foreign refiner shall treat the gasoline as 

Non-Certified Sulfur-FRGAS, and the foreign refiner shall exclude the gasoline volume 

and properties from its gasoline sulfur compliance calculations under §80.205.

(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.
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(B) Identify, and report as a finding, each occasion the load port and port of entry

parameter and volume results differ by more than the amounts allowed in paragraph (g) 

of this section, and determine whether the foreign refiner adjusted its refinery

calculations as required in paragraph (g) of this section.

(ii) Obtain the documents used by the independent third party to determine 

transportation and storage of the Certified Sulfur-FRGAS from the refinery to the load 

port, under paragraph (f) of this section. Obtain tank activity records for any storage tank

where the Certified Sulfur-FRGAS is stored, and pipeline activity records for any

pipeline used to transport the Certified Sulfur-FRGAS, prior to being loaded onto the 

vessel. Use these records to determine whether the Certified Sulfur-FRGAS was 

produced at the refinery that is the subject of the attest engagement, and whether the 

Certified Sulfur-FRGAS was mixed with any Non-Certified Sulfur-FRGAS, Non-SulfurFRGAS, or any Certified Sulfur-FRGAS produced at a different refinery.

(5) Select a sample from the list of vessels identified in paragraph (h)(3) of this 

section used to transport certified and Non-Certified Sulfur-FRGAS, in accordance with 

the attest engagement guidelines of §80.127, and for each vessel selected perform the 

following:

(i) Obtain a commercial document of general circulation that lists vessel arrivals 

and departures, and that includes the port and date of departure of the vessel, and the port 

of entry and date of arrival of the vessel.

(ii) Agree the vessel's departure and arrival locations and dates from the 

independent third party and 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).
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(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.

(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 

Sulfur-FRGAS, or as Certified Sulfur-FRGAS or as Non-Certified Sulfur-FRGAS.

(D) Transfers of title or custody to Sulfur-FRGAS.

(E) Sampling and testing of Sulfur-FRGAS.

(F) Work performed and reports prepared by independent third parties and by

independent auditors under the requirements of this section and §80.415, including work 

papers.

(G) Reports prepared for submission to EPA, and any work papers related to such 

reports.

(vi) Inspections and audits by EPA may include taking samples of gasoline or 

blendstock, and interviewing employees.

(vii) Any employee of the foreign refiner must be made available for interview by

the EPA inspector or auditor, on request, within a reasonable time period.
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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) (42 U.S.C. 7413(c)(2)).

(6) The foreign refiner, or its agents or employees, must not seek to detain or to 

impose civil or criminal remedies against EPA inspectors or auditors, whether EPA 

employees or EPA contractors, for actions performed within the scope of EPA 

employment related to the provisions of this section.

(7) The commitment required by this paragraph (i) must be signed by the owner 

or president of the foreign refiner business.

(8) In any case where FRGAS produced at a foreign refinery is stored or 

transported by another company between the refinery and the vessel that transports the 

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 limitation based on sovereign immunity, with respect to 
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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) (42 U.S.C. 7413(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)

(42 U.S.C. 7413(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, 
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Surety Bond Branch, 3700 East-West Highway, Room 6A04, Hyattsville, MD, 20782. 

Also available on the internet at http://www.fms.treas.gov/c570/c570.html ); and

(iii) Include a commitment that the bond will remain in effect for at least five

years following the end of latest averaging period that the foreign refiner produces 

gasoline pursuant to the requirements of this subpart O.

(5) On any occasion a foreign refiner bond is used to satisfy any judgment, the 

foreign refiner shall increase the bond to cover the amount used within 90 days of the 

date the bond is used.

(l) English language reports. Any report or other document submitted to EPA by

any foreign refiner must be in English, or must include an English language translation.

(m) Prohibitions.

(1) No person may combine Certified Sulfur-FRGAS with any Non-Certified 

Sulfur-FRGAS or Non-Sulfur-FRGAS, and no person may combine Certified SulfurFRGAS 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 

Sulfur-FRGAS or as Non-Sulfur-FRGAS, and each batch classified as Sulfur-FRGAS 

shall be further classified as Certified Sulfur-FRGAS or as Non-certified Sulfur-FRGAS.

(2) Gasoline shall be classified as Certified Sulfur-FRGAS or as Non-Certified 

Sulfur-FRGAS according to the designation by the foreign refiner if this designation is 

supported by product transfer documents prepared by the foreign refiner as required in 

paragraph (d) of this section, unless the gasoline is classified as Non-Certified SulfurFRGAS under paragraph (g) of this section.

(3) For each gasoline batch classified as Sulfur-FRGAS, any 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.

(B) Use the foreign refiner’s Sulfur-FRGAS certification to determine the name 

and EPA-assigned registration number of the foreign refinery that produced the SulfurFRGAS.
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(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 this 

subpart O, including sulfur content standards specified in §80.1603, for any imported 

gasoline that is not classified as Certified Sulfur-FRGAS under paragraph (n)(2) of this 

section.

(o) Truck imports of Certified Sulfur-FRGAS produced by a foreign small refiner 

or foreign small volume refinery.

(1) Any refiner whose Certified Sulfur-FRGAS is transported into the United 

States by truck may petition EPA to use alternative procedures to meet all 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.

(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.
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(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.

(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 
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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. 

(3) If the annual average sulfur standard is incorrect or credit generation was 

inappropriate, recalculate compliance using the appropriate sulfur standard and using 

appropriate credits and report as a finding. 

(b) EPA reports. 

(1) Obtain and read a copy of the refinery's or importer's annual sulfur reports 

filed with EPA for the year.

(2) Agree the yearly volume of gasoline reported to EPA in the sulfur reports with 

the inventory reconciliation analysis under the attest engagement provisions of §80.128.

(3) Calculate the annual average sulfur level for all gasoline and agree that value 

with the value reported to EPA.

(4) Obtain and read a copy of the refinery's or importer's sulfur credit report.

(5) Agree the information in the refinery's or importer's batch reports filed with 

EPA under §§80.75 and 80.105, and any laboratory test results, with the information 

contained in the annual sulfur report required under §80.1652.
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(c) Credit generation before 2017. In the case of a refinery that generates credits 

during 2014 through 2016:

(1) Obtain a written representation from the company representative stating the 

refinery produces gasoline from crude oil.

(2) Obtain the annual average sulfur level from paragraph (b)(3) of this section.

(3) Compute and report as a finding the total number of sulfur credits generated, 

and agree this value with the value reported to EPA.

(d) Credit generation in 2017 and thereafter. The following procedures shall be 

completed for a refinery or importer that generates credits in 2017 and thereafter:

(1) Obtain the annual average sulfur level for gasoline from paragraph (b)(3) of 

this section.

(2) If the sulfur value under paragraph (d)(1) of this section is less than 10 ppm, 

compute and report as a finding the difference between the sulfur level under paragraph 

(d)(1) of this section and 10 ppm.

(3) Compute and report as a finding the total number of sulfur credits generated, 

and agree this number with the number reported to EPA.

(e) Credit purchases and sales. The following attest procedures shall be 

completed for a refinery or importer that is a transferor or transferee of credits during an 

averaging period:

(1) Obtain contracts or other documents for all credits transferred to another 

refinery or importer during the year being reviewed; compute and report as a finding the 

number and year of creation of credits represented in these documents as being 

transferred away; and agree with the report to EPA.

(2) Obtain contracts or other documents for all credits received during the year 

being reviewed; compute and report as a finding the number and year of creation of 

credits represented in these documents as being received; and agree with the report to 

EPA.

(f) Credit expiration. A refinery or importer that possesses credits during an 

averaging period must obtain a list of all credits in the refiner's or importer's possession at 

any time during the year being reviewed, identified by the year of creation of the credits.

(g) Credit reconciliation. The following attest procedures shall be completed each 

year credits were in the refiner's or importer's possession at any time during the year:

(1) Obtain the credits remaining or the credit deficit from the previous year from 

the refiner's or importer's report to EPA for the previous year.

(2) Compute and report as a finding the net credits remaining at the conclusion of 

the year being reviewed by totaling:
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(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]

§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 

Spark-Ignition 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

38. The authority citation for part 85 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart F—[Amended]

39. 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.

* * * * *

40. Section 85.515 is amended by revising paragraph (b)(9)(iii) to read as follows:

§ 85.515 Exemption provisions for intermediate age vehicles/engines.

* * * * *

(b) * * *

(9) * * *

(iii) In addition to conducting OBD testing described in this paragraph (b)(9), you must 

submit to EPA the following statement of compliance if the OEM vehicles/engines were 

required to be OBD-equipped:

The test group/engine family converted to an alternative fuel has fully functional 

OBD systems and therefore meets the OBD requirements specified in 40 CFR 86 

when operating on the alternative fuel.

* * * * *

41. 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) * * *
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(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]

42. Section 85.1515 is revised to read as follows:

§ 85.1515 Emission standards and test procedures applicable to imported 

nonconforming motor vehicles and motor vehicle engines.

(a) Notwithstanding any other requirements of this subpart, any motor vehicle or motor 

vehicle engine conditionally imported pursuant to §85.1505 or §85.1509 and required to 

be emission tested shall be tested using the FCT at 40 CFR part 86 applicable to current 

model year motor vehicles and motor vehicle engines at the time of testing or reduced 

testing requirements as follows:

(1) ICIs are eligible for reduced testing under this paragraph (a) subject to the 

following conditions:

(i) The OEM must have a valid certificate of conformity covering the vehicle.

(ii) The vehicle must be in its original configuration as certified by the OEM. 

This applies for all emission-related components, including the electronic control 

module, engine calibrations, and all evaporative/refueling control hardware. It 

also applies for OBD software and hardware, including all sensors and actuators. 

(iii) The vehicle modified as described in paragraph (a)(1)(ii) of this section must 

fully comply with all applicable emission standards and requirements.

(iv) Vehicles must have the proper OBD systems installed and operating. When 

faults are present, the ICI must test and verify the system’s ability to find the 

faults (such as disconnected components), set codes, and illuminate the light, and 

set readiness codes as appropriate for each vehicle. When no fault is present, the 

ICI must verify that after sufficient prep driving (typically one FTP test cycle), all 

OBD readiness codes are set and the OBD system does not indicate a malfunction 

(i.e., no codes set and no light illuminated).

(v) The ICI may not modify more than 300 vehicles in any given model year 

using reduced testing provisions in this paragraph (a). 

(vi) The ICI must state in the application for certification that it will meet all the 

conditions in this paragraph (a)(1).

(2) The following provisions allow for ICIs to certify vehicles with reduced testing:

(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, 
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that vehicles comply with any of the following standards that apply instead of 

submitting test data:

(A) Cold temperature CO and NMHC emission standards specified in 40 CFR 

86.1811.

(B) SFTP emission standards specified in 40 CFR 86.1811 and 86.1816 for all 

pollutants.

(C) For anything other than diesel-fueled vehicles, PM emission standards 

specified in 40 CFR 86.1811 and 86.1816.

(D) Any running loss, refueling, spitback, bleed emissions, and leak standards 

specified in 40 CFR part 86, subparts A and S. 

(ii) You must perform testing and submit test data as follows to demonstrate 

compliance with emission standards:

(A) Exhaust and fuel economy tests. You must measure emissions over the 

FTP driving cycle and the highway fuel economy driving cycle as specified in 

40 CFR 600.109 to meet the fuel economy requirements in 40 CFR part 600 

and demonstrate compliance with the exhaust emission standards in 40 CFR 

part 86 (other than PM). Measure exhaust emissions and fuel economy with 

the same test procedures used by the original manufacturer to test the vehicle 

for certification. However, you must use an electric dynamometer meeting 

the requirements of §86.108 or 40 CFR part 1066, subpart B, unless we 

approve a different dynamometer based on excessive compliance costs. If you 

certify based on testing with a different dynamometer, you must state in the 

application for certification that all vehicles in the emission family will 

comply with emission standards if tested on an electric dynamometer. 

(B) Evaporative emission test. You may measure evaporative emissions as 

specified in this paragraph (a)(2)(ii)(B) to demonstrate compliance with the 

evaporative emission standards in 40 CFR part 86 instead of the otherwise 

specified procedures. Use measurement equipment for evaporative 

measurements specified in 40 CFR part 86, subpart B, except that the 

evaporative emission enclosure does not need to accommodate varying 

ambient temperatures. The evaporative measurement procedure is integral to 

the procedure for measuring exhaust emissions over the FTP driving cycle as 

described in paragraph (a)(ii)(2)(A) of this section. Perform canister 

preconditioning using the same procedure used by the original manufacturer 

to certify the vehicle; perform this canister loading before the initial 

preconditioning drive. Perform a diurnal emission test at the end of the 

stabilization period before the exhaust emission test by heating the fuel from 

60 to 84°F, either by exposing the vehicle to increasing ambient temperatures 

or by applying heat directly to the fuel tank. Measure hot soak emissions as 

described in 40 CFR 86.138-96(k). We may approve alternative measurement 

procedures that are equivalent to or more stringent than the specified 
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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 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).
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(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 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
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Page 563 of 903

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 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) 
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and (ii) of this section, but does not have sufficient credits to cover vehicles 

imported under such certificate, the Administrator may issue such certificate if the 

ICI has also obtained a certificate of conformity for vehicles certified using a cold 

temperature NMHC family emission level lower than that required under 

paragraphs (c)(8)(i) and (ii) of this section. The ICI may then import vehicles to 

the higher cold temperature NMHC family emission level only to the extent that it 

has generated sufficient credits from vehicles certified to a family emission level 

lower than the cold temperature NMHC fleet average standard during the same 

model year.

(vi) ICIs using cold temperature NMHC family emission levels higher than the 

cold temperature NMHC fleet average standards specified in paragraphs (c)(8)(i) 

and (ii) of this section must monitor their imports so that they do not import more 

vehicles certified to such family emission levels than their available credits can 

cover. ICIs must not have a credit deficit at the end of a model year and are not 

permitted to use the deficit carryforward provisions provided in 40 CFR 86.1864–

10.

(vii) The Administrator may condition the certificates of conformity issued to 

ICIs as necessary to ensure that vehicles subject to this paragraph (c)(8) comply

with the applicable cold temperature NMHC fleet average standard for each 

model year.

(d) Except as provided in paragraph (c) of this section, ICI's must not participate in 

emission-related programs for emissions averaging, banking and trading, or 

nonconformance penalties.
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Table 1 to §85.1515—Emission Standards Applicable to Imported Light-Duty Motor 

Vehicles1,2,3

OP Year Hydrocarbon Carbon

monoxide

Oxides of 

nitrogen

Diesel 

Particulate

Evaporative 

hydrocarbon

Useful life 

(years/miles)

1968–76 1.5 gpm 15 gpm 3.1 gpm 6.0 g/test 5/50,000

1977–79 1.5 gpm 15 gpm 2.0 gpm 6.0 g/test 5/50,000

1980 0.41 gpm 7.0 gpm 2.0 gpm 6.0 g/test 5/50,000

1981 0.41 gpm 3.4 gpm 1.0 gpm 2.0 g/test 5/50,000

1982–86 0.41 gpm 3.4 gpm 1.0 gpm 0.60 gpm 2.0 g/test 5/50,000

1987–93 0.41 gpm 3.4 gpm 1.0 gpm 0.20 gpm 2.0 g/test 5/50,000

1994 and 

later (

4

) (

4

) (

4

) (

4

) (

4

) (

4

)

1Diesel particulate standards apply only to diesel fueled light-duty vehicles. Evaporative hydrocarbon 

standards apply only to non-diesel fueled light-duty vehicles. For alternative fueled light-duty vehicles, the 

evaporative hydrocarbon standard is interpreted as organic material hydrocarbon equivalent grams carbon 

per test, as applicable.

2No crankcase emissions shall be discharged into the ambient atmosphere from any non-diesel fueled lightduty vehicle.

3All light-duty vehicles shall meet the applicable emission standards at both low and high-altitudes 

according to the procedures specified in 40 CFR part 86 for current model year motor vehicles at the time 

of testing.

4

Specified in 40 CFR part 86 for the OP year of the vehicle, as described in paragraph (c) of this section.
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Table 2—Emission Standards Applicable to Imported Light-Duty Trucks1,2,3,4,5

OP year Hydrocarbon Carbon 

monoxide

Oxides of 

nitrogen

Diesel 

Particulate

Evaporative 

hydrocarbon

Useful life 

(years/miles)

1968–78 2.0 gpm 20 gpm 3.1 gpm 6.0 g/test 5/50,000

1979–80 1.7 gpm 18 gpm 2.3 gpm 6.0 g/test 5/50,000

1981 1.7 gpm 18 gpm 2.3 gpm 2.0 g/test 5/50,000

1982–83 1.7 gpm

(2.0)

18 gpm

(26)

2.3 gpm

(2.3)

0.60 gpm

(0.60)

2.0 g/test

(2.6) 5/50,000

1984 0.80 gpm

(1.0)

10 gpm

(14)

2.3 gpm

(2.3)

0.60 gpm

(0.60)

2.0 g/test

(2.6) 5/50,000

1985–86 0.80 gpm

(1.0)

10 gpm

(14)

2.3 gpm

(2.3)

0.60 gpm

(0.60)

2.0 g/test

(2.6) 11/120,000

1987 0.80 gpm

(1.0)

10 gpm

(14)

2.3 gpm

(2.3)

0.26 gpm

(0.26)

2.0 g/test

(2.6) 11/120,000

1988–89 0.80 gpm

(1.0)

10 gpm

(14)

1.2 gpm6

(1.2)

0.26 gpm7

(2.0)

2.0 g/test

(2.6) 11/120,000

 

0.80 gpm

(1.0)

10 gpm

(14)

1.7 gpm6

(1.7)

0.45 gpm7

(0.26)

2.0 g/test

(2.6) 11/120,000

 

0.80 gpm

(1.0)

10 gpm

(14)

2.3 gpm6

(2.3)

0.45 gpm7

(0.26)

2.0 g/test

(2.6) 11/120,000

1990–93 0.80 gpm

(1.0)

10 gpm

(14)

1.2 gpm8

(1.2)

0.26 gpm7

(0.26)

2.0 g/test

(2.6) 11/120,000

 

0.80 gpm

(1.0)

10 gpm

(14)

1.7 gpm8

(1.7)

0.45 gpm7

(0.26)

2.0 g/test

(2.6) 11/120,000

1994 

and later (

9

) (

9

) (

9

) (

9

) (

9

) (

9

)

1Diesel particulate standards apply only to diesel fueled light-duty trucks. Evaporative hydrocarbon 

standards apply only to non-diesel fueled light-duty trucks. For alternative fueled light-duty trucks, the 

evaporative hydrocarbon standard is interpreted as organic material hydrocarbon equivalent grams carbon 

per test, as applicable.

2No crankcase emissions shall be discharged into the ambient atmosphere from any non-diesel fueled lightduty truck.

3A carbon monoxide standard of 0.50% of exhaust flow at curb idle is applicable to all 1984 and later 

model year light-duty trucks sold to, or owned by, an importer for principal use at other than a designated 

high-altitude location. This requirement is effective for light-duty trucks sold to, or owned by an importer 

for principal use at a designated high-altitude location beginning with the 1988 model year.

4All 1982 OP year and later light-duty trucks sold to, or owned by, an importer for principal use at a 

designated high-altitude location shall meet high-altitude emission standards according to the requirements 

specified in 40 CFR part 86 for current model year light-duty trucks at the time of testing.

5

Standards in parentheses apply to motor vehicles sold to, or owned by, an importer for principal use at a 

designated high-altitude location. These standards must be met at high-altitude according to the procedures 

specified in 40 CFR part 86 for current model year motor vehicles at the time of testing.
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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]

43. 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.

§ 85.2201 Applicability. 

(a) This subpart describes the test provisions to be employed in conjunction with the 

Emissions Performance Warranty in subpart V of this part. These provisions generally 

rely on a vehicle’s onboard diagnostic system (OBD) to indicate whether a vehicle passes 

or fails the test.

(b) The provisions of this subpart may be used to establish warranty eligibility for lightduty vehicles, light-duty trucks, and medium-duty passenger vehicles when tested during 

the useful life as prescribed in subpart V of this part.

§ 85.2207 Onboard diagnostic test standards.

(a) A vehicle shall fail the OBD test if it is a 1996 or newer vehicle and the vehicle 

connector is missing, has been tampered with, or is otherwise inoperable.

(b) A vehicle shall fail the OBD test if the malfunction indicator light (MIL) is 

commanded to be illuminated and it is not visually illuminated according to visual 

inspection.

(c) A vehicle shall fail the OBD test if the MIL is commanded to be illuminated for one 

or more diagnostic trouble codes (DTCs), as described in 40 CFR 86.1806. 

§ 85.2222 Onboard diagnostic test procedures.

The test sequence for the OBD inspection shall consist of the following steps:
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(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 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.
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§ 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.

§ 85.2231 Onboard diagnostic test equipment requirements.

(a) The test system interface to the vehicle shall include a plug that conforms to the 

requirements and specifications of 40 CFR 86.1806. 

(b) The test system shall be capable of communicating with the standard data link 

connector of vehicles with certified OBD systems.

(c) The test system shall be capable of checking for OBD monitors and the evaluation 

status of supported monitors (test complete/test not complete) in Mode $01 PID $01, as 

well as be able to request the DTCs, consistent with the requirements and specifications 

of 40 CFR 86.1806. 

Part 86— Control of Emissions from New and In-use Highway Vehicles and 

Engines

44. The authority citation for part 86 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

45. 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.
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(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 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]

46. 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.

47. 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]

48. 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).

49. 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 —

* * * * *

50. Section 86.004-21 is amended as follows:

a. By revising the introductory text
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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]

51. Section 86.004-25 is amended by removing and reserving paragraph (b)(4)(ii) 

and (b)(4)(iv).

52. Section 86.004-26 is amended as follows:

a. By removing the introductory text.

b. By removing and reserving paragraphs (a) and (b).

c. By revising paragraph (d).

§86.004-26 Mileage and service accumulation; emission measurements.

* * * * *

(d)(1) This paragraph (d) applies for heavy-duty engines.

(2)(i) The results of all emission testing shall be supplied to the Administrator. The 

manufacturer shall furnish to the Administrator explanation for voiding any test. 

The Administrator will determine if voiding the test was appropriate based upon 

the explanation given by the manufacturer for the voided test. Tests between test 

points may be conducted as required by the Administrator. Data from all tests 

(including voided tests) may be submitted weekly to the Administrator, but shall 

be delivered to the Administrator within 7 days after completion of the test. In 

addition, all test data shall be compiled and provided to the Administrator in 

accordance with §86.007–23. Where the Administrator conducts a test on a 

durability data vehicle at a prescribed test point, the results of that test will be 

used in the calculation of the deterioration factor.

(ii) The results of all emission tests shall be recorded and reported to the 

Administrator. These test results shall be rounded as specified in 40 CFR part 

1065 to the number of decimal places contained in the applicable emission 

standard expressed to one additional significant figure.

(3) Whenever a manufacturer intends to operate and test a vehicle (or engine) that 

may be used for emission data, the manufacturer shall retain in its records all 

information concerning all emission tests and maintenance, including vehicle (or 

engine) alterations to represent other vehicle (or engine) selections. This information 

shall be submitted, including the vehicle (or engine) description and specification 
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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]

53. Section 86.004-28 is amended by removing the introductory text and by removing 

and reserving paragraphs (a), (b), (f), and (g).

54. 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.

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.”

55. 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).”

56. 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 
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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.

* * * * *

57. Section 86.007-17 is revised to read as follows:

§ 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]

58. 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).

59. 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]

60. 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).

61. Section 86.007-35 is amended as follows:

a. By revising paragraph (a) introductory text.

b. By removing and reserving paragraphs (a)(1) and (a)(2)

c. By revising paragraph (c).

d. By removing and reserving paragraphs (d), (f), and (i).

§86.007-35 Labeling.

* * * * *

(a) The manufacturer of any motor vehicle (or motor vehicle engine) subject to the 

applicable emission standards (and family emission limits, as appropriate) of this subpart, 

shall, at the time of manufacture, affix a permanent legible label, of the type and in the 

manner described below, containing the information hereinafter provided, to all 

production models of such vehicles (or engines) available for sale to the public and 

covered by a Certificate of Conformity under §86.007–30(a).
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* * * * *

(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”.

* * * * *

62. 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 heavyduty 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.

* * * * *

(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.

* * * * *

63. 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 

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.

* * * * *

(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 
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only with ultra low-sulfur diesel fuel (meeting EPA specifications for highway diesel 

fuel, including a 15 ppm sulfur cap).”

* * * * *

64. Section 86.016-1 is amended by revising paragraphs (a), (b), and (c) and adding 

paragraphs (g) and (h) to read as follows:

§ 86.016-1 General applicability.

(a) Applicability. The provisions of this subpart apply for certain types of new heavyduty engines and vehicles as described in this paragraph (a). Note that this subpart does 

not apply for light-duty vehicles, light-duty trucks, or medium-duty passenger vehicles 

(see subpart S of this part for requirements that apply for those vehicles). In some cases, 

manufacturers of heavy-duty engines and vehicles can choose whether to meet the 

requirements of this subpart or the requirements of subpart S of this part; those provisions 

are therefore considered optional, but only to the extent that manufacturers comply with 

the other set of requirements. In cases where a provision applies only for a certain 

vehicle group based on its model year, vehicle class, motor fuel, engine type, or other 

distinguishing characteristics, the limited applicability is cited in the appropriate section. 

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.
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(5) The provisions of this subpart related to onboard diagnostics apply for dieselcycle and Otto-cycle heavy-duty engines and vehicles as follows:

(i) Engines installed in vehicles above 14,000 pounds GVWR must meet the 

onboard diagnostic requirements specified in §86.010-18.

(ii) Engines installed in vehicles at or below 14,000 pounds GVWR 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.

65. Section 86.082-2 is amended by adding definitions for “Round” and “United States” 

in alphabetical order to read as follows. 

§ 86.082-2 Definitions.

* * * * *

Round has the meaning given in 40 CFR 1065.1001, unless otherwise specified.

* * * * *

United States has the meaning given in 40 CFR 1068.30. 

* * * * *

§86.085-37—[Amended]

66. 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]

67. Section 86.091-29 is amended by removing and reserving paragraph (a). 

68. Section 86.094-7 is amended as follows:
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a. By removing and reserving paragraph (h)(1).

b. By adding paragraph (h)(6).

§ 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]

69. Section 86.094-14 is amended by removing and reserving paragraphs (c)(5) and 

(c)(7)(i)(A)(1). 

§86.094-21—[Amended]

70. 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]

71. 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]

72. 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).

73. 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]
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* * * * *

(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. 

* * * * *

(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]

74. 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]

75. Section 86.098-23 is amended by removing and reserving paragraphs (b)(1)(i), 

(e)(2), and (e)(3). 

Subpart B—[Amended]

76. 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]

77. 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.

78. 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:
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(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 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 
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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.

(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.

79. 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.

* * * * *
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§86.107-96—[Amended]

80. Section 86.107-96 is amended by removing paragraph (e). 

81. 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]

82. Section 86.113-94 is amended by removing and reserving paragraph (a). 

83. Section 86.113-04 is amended by revising paragraphs (a)(2) and (a)(3)(i) to read as 

follows:

§ 86.113-04 Fuel specifications.

* * * * *

(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 
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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 highaltitude standards for a given vehicle are the LEV III standards that apply for lowaltitude 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.

* * * * *

84. Section 86.113-07 is amended by revising the introductory text and paragraph (a) to 

read as follows:

§86.113-07 Fuel specifications.

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.”
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(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).

* * * * *

85. 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 
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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: 

* * * * *

86. 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 ±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.

* * * * *

87. Section 86.128-79 is amended by revising paragraph (d) to read as follows: 

§86.128-79 Transmissions.

* * * * *
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(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]

88. Section 86.129-80 is amended by removing and reserving paragraph (a). 

89. 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 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.

90. 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]
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91. Section 86.132-96 is amended by removing and reserving paragraph (k). 

92. 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 removed. Without this demonstration, tank pressure must not exceed 10 inches of 

water during the diurnal emission test. 

* * * * *

93. 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.

* * * * *

94. Section 86.135-90 is amended by revising paragraphs (a) and (d) to read as follows: 

§86.135-90 Dynamometer procedure.

(a) The dynamometer run consists of two tests— a “cold” start test, after a minimum 12-

hour and a maximum 36-hour soak according to the provisions of §§86.132 and 86.133, 

and a “hot” start test following the “cold” start by 10 minutes. Engine startup (with all 

accessories turned off), operation over the UDDS and engine shutdown make a complete 

cold start test. Engine startup and operation over the first 505 seconds of the driving 

schedule complete the hot start test. The exhaust emissions are diluted with ambient air in 

the dilution tunnel as shown in Figure B94-5 and Figure B94-6. A dilution tunnel is not 

required for testing vehicles waived from the requirement to measure particulate matter. 
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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.

* * * * *

95. Section 86.137-94 is amended by revising paragraphs (b)(16) through (b)(24) to read 

as follows:

§ 86.137-94 Dynamometer test run, gaseous and particulate emissions.

* * * * *

(b) * * *

(16) Immediately after the end of the sample period, turn off the cooling fan and close the 

engine compartment cover.

(17) Turn off the CVS or disconnect the exhaust tube from the tailpipe(s) of the vehicle.

(18) Repeat the steps in paragraphs (b)(2) through (b)(12) of this section for the hot start 

test, except only two evacuated sample bags, two methanol sample impingers, two 
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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.

(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.

96. 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. 

* * * * *

97. Section § 86.143-96 is amended by revising paragraph (c) to read as follows:

§ 86.143-96 Calculations; evaporative emissions.

* * * * *
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(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 

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]

98. 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:

(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. 
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(2) You may use the test fuel specified in this paragraph (a)(2) for vehicles that are 

not yet subject to exhaust testing with an ethanol-blend test fuel under §86.113. 

Manufacturers may certify based on this fuel using carryover data until testing with 

the ethanol-blend test fuel is required. The following specifications apply for 

gasoline test fuel without ethanol:

Table 1 of §86.213–Cold temperature test fuel specifications for gasoline without 

ethanol

Item Regular Premium1 Reference 

Procedure2

(RON+MON)/2387.8±0.3 92.3±0.5 ASTM D2699 Sensitivity3

7.5 7.5

Distillation Range (°F):

 Evaporated initial boiling point

 10% evaporated

 50% evaporated

 90% evaporated

 Evaporated final boiling point

76 – 96

98 - 118

179 - 214

316 - 346

413 Maximum

76 – 96

105 - 125

195 - 225

316 - 346

413 Maximum

ASTM D86

Hydrocarbon composition (vol 

%):

 Olefins

 Aromatics

 Saturates

12.5±0.5

26.4±4.0

Remainder

10.5±0.5

32.0±4.0

Remainder

ASTM D1319

Lead, g/gallon 0.01, 

Maximum

0.01, 

Maximum ASTM D3237

Phosphorous, g/gallon 0.005 

Maximum

0.005 

Maximum ASTM D3231

Total sulfur, wt. % 0.0015 – 0.008 0.0015 –

0.0084 ASTM D3120

RVP, psi 11.5±0.3 11.5±0.3 ASTM 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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99. Subpart D, consisting of §§ 86.301-79 through 86.348-79, is removed.

Subpart F—[Amended]

§ 86.505-78 – [Removed]

100. Subpart F is amended by removing § 86.505-78.

§86.513-94—[Amended]

101. Section 86.513-94 is amended by removing and reserving paragraph (a) and by 

removing paragraphs (e) and (f). 

102. Section 86.515-78 is amended by revising paragraphs (a) and (d) to read as 

follows: 

§ 86.515-78 EPA urban dynamometer driving schedule.

(a) The dynamometer driving schedules are listed in appendix I. The driving schedules 

are defined by a smooth trace drawn through the specified speed vs. time relationships. 

They consist of a nonrepetitive series of idle, acceleration, cruise, and deceleration modes 

of various time sequences and rates. Appropriate driving schedules are as follows:

(1) Class I—Appendix I(b).

(2) Class II—Appendix I(a)(2).

(3) Class III—Appendix I(a)(2).

* * * * *

(d) For motorcycles with an engine displacement less than 50 cc and a top speed less than 

58.7 km/hr (36.5 mph), the speed indicated for each second of operation on the applicable 

Class I driving trace (speed versus time sequence) specified in appendix I(b) shall be 

adjusted downward by the ratio of actual top speed to specified maximum test speed. 

Calculate the ratio with three significant figures by dividing the top speed of the 

motorcycle in km/hr by 58.7. For example, for a motorcycle with a top speed of 48.3 

km/hr (30 mph), the ratio would be 48.3/58.7 = 0.823. The top speed to be used under 

this section shall be indicated in the manufacturer's application for certification, and shall 

be the highest sustainable speed of the motorcycle with an 80 kg rider on a flat paved 

surface. If the motorcycle is equipped with a permanent speed governor that is unlikely to 

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]

103. 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 
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not be required to perform any of the test procedures in subpart B of this part relating to 

evaporative emission testing, other than refueling emissions testing, except as specified in 

paragraph (a)(2) of this section.

(1) The Administrator may omit any of the testing procedures described in paragraph 

(a) of this section. Further, the Administrator may, on the basis of a written 

application by a manufacturer, approve optional test procedures other than those in 

subparts B and C of this part for any motor vehicle which is not susceptible to 

satisfactory testing using the procedures in subparts B and C of this part.

(2) The following exceptions to the test procedures in subpart B of this part are 

applicable to Selective Enforcement Audit testing:

(i) For mileage accumulation, the manufacturer may use test fuel meeting the 

specifications for mileage and service accumulation fuels of §86.113. Otherwise, 

the manufacturer may use fuels other than those specified in this section only with 

the advance approval of the Administrator.

(ii) The manufacturer may measure the temperature of the test fuel at other than 

the approximate mid-volume of the fuel tank, as specified in §86.131–96(a) with 

only a single temperature sensor, and may drain the test fuel from other than the 

lowest point of the tank, as specified in §§86.131–96(b) and 86.152–98(a), 

provided an equivalent method is used. Equivalency documentation shall be 

maintained by the manufacturers and shall be made available to the Administrator 

upon request. Additionally, for any test vehicle that has remained under 

laboratory ambient temperature conditions for at least 6 hours prior to testing, the 

vehicle soak described in §86.132–96(c) may be eliminated upon approval of the 

Administrator. In such cases, the vehicle shall be operated through the 

preconditioning drive described in §86.132–96(c) immediately following the fuel 

drain and fill procedure described in §86.132–96(b).

(iii) The manufacturer may perform additional preconditioning on Selective 

Enforcement Audit test vehicles other than the preconditioning specified in 

§86.132 only if the additional preconditioning was performed on certification test 

vehicles of the same configuration.

(iv) [Reserved] 

(v) The manufacturer may substitute slave tires for the drive wheel tires on the 

vehicle as specified in §86.135–90(e): Provided, that the slave tires are the same 

size.

(vi) [Reserved] 

(vii) In performing exhaust sample analysis under §86.140–94.

(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 
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infrared analyzers are turned off and the phototube high voltage supply to the 

chemiluminescent analyzers is placed in the standby position.)

(B) The manufacturer shall exercise care to prevent moisture from condensing 

in the sample collection bags.

(viii) The manufacturer need not comply with §86.142 or §86.155, since the

records required therein are provided under other provisions of this subpart G.

(ix) If a manufacturer elects to perform the background determination procedure 

described in paragraph (a)(2)(xi) of this section in addition to performing the 

refueling emissions test procedure, the elapsed time between the initial and final 

FID readings shall be recorded, rounded to the nearest second rather than minute 

as described in §86.154–98(e)(8). In addition, the vehicle soak described in 

§86.153–98(e) shall be conducted with the windows and luggage compartment of 

the vehicle open.

(x) The Administrator may elect to perform a seal test, described in §86.153–

98(b), of both integrated and non-integrated systems instead of the full refueling 

test. When testing non-integrated systems, a manufacturer may conduct the 

canister purge described in §86.153–98(b)(1) directly following the 

preconditioning drive described in §86.132–96(e) or directly following the 

exhaust emissions test described in §86.137–96.

(xi) In addition to the refueling test, a manufacturer may elect to perform the 

following background emissions determination immediately prior to the refueling 

measurement procedure described in §86.154, provided EPA is notified of this 

decision prior to the start of testing in an SEA.

(A) The SHED shall be purged for several minutes immediately prior to the 

background determination. Warning: If at any time the concentration of 

hydrocarbons, of methanol, or of methanol and hydrocarbons exceeds 15,000 

ppm C, the enclosure should be immediately purged. This concentration 

provides a 4:1 safety factor against the lean flammability limit.

(B) The FID (or HFID) hydrocarbon analyzer shall be zeroed and spanned 

immediately prior to the background determination. If not already on, the 

enclosure mixing fan and the spilled fuel mixing blower shall be turned on at 

this time.

(C) Place the vehicle in the SHED. The ambient temperature level 

encountered by the test vehicle during the entire background emissions 

determination shall be 80 °F ±3 °F. The windows and luggage compartment of 

the vehicle must be open and the gas cap must be secured.

(D) Seal the SHED. Immediately analyze the ambient concentration of 

hydrocarbons in the SHED and record. This is the initial background 

hydrocarbon concentration.

(E) Soak the vehicle for ten minutes ±1 minute.
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(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).

(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 
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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 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. 

* * * * *

104. 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, 
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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 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]

105. Section 86.610-98 is amended by removing and reserving paragraph (c)(2).

106. 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:

(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 
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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 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]
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107. Subpart H, consisting of §§ 86.701-94 through 86.709-99, is removed.

Subpart M—[Removed]

108. Subpart M, consisting of §§ 86.1201-90 through 86.1246-96, is removed.

Subpart N--Exhaust Test Procedures for Heavy-duty Engines

109. 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]

110. 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, 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]

111. 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

112. Newly redesignated § 86.1305 is revised to read as follows:
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§ 86.1305 Introduction; structure of subpart.

(a) This subpart specifies the equipment and procedures for performing exhaust-emission 

tests on Otto-cycle and diesel-cycle heavy-duty engines. Subpart A of this part sets forth 

the emission standards and general testing requirements to comply with EPA certification 

procedures.

(b) Use the applicable equipment and procedures for spark-ignition or compressionignition engines in 40 CFR part 1065 to determine whether engines meet the duty-cycle 

emission standards in subpart A of this part. Measure the emissions of all regulated 

pollutants as specified in 40 CFR part 1065. Use the duty cycles and procedures specified 

in §§ 86.1333, 86.1360, and 86.1362. Adjust emission results from engines using 

aftertreatment technology with infrequent regeneration events as described in § 86.004–

28.

(c) The provisions in §§86.1370 and §§86.1372 apply for determining whether an engine 

meets the applicable not-to-exceed emission standards.

(d) Measure smoke using the procedures in subpart I of this part for evaluating whether 

engines meet the smoke standards in subpart A of this part.

(e) Use the fuels specified in 40 CFR part 1065 to perform valid tests, as follows:

(1) For service accumulation, use the test fuel or any commercially available fuel that 

is representative of the fuel that in-use engines will use.

(2) For diesel-fueled engines, use the ultra low-sulfur diesel fuel specified in 40 CFR 

part 1065 for emission testing.

(3) For gasoline-fueled engines, use the appropriate 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.

113. 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:
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%  

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.

114. Newly redesignated § 86.1360 is amended by revising paragraphs (b)(1), (c), and 

(f)(3) to read as follows:

§ 86.1360 Supplemental emission test; test cycle and procedures.

* * * * *

(b) * * *

(1) Perform testing as described in §86.1362 for determining whether an engine meets the 

applicable standards when measured over the supplemental emission test.

* * * * *

(c) The engine speeds A, B and C, referenced in the table in paragraph (b)(1) of this 

section, must be determined as follows:

Speed A = nlo+ 0.25 × (nhi−nlo)

Speed B = nlo+ 0.50 × (nhi−nlo)

Speed C = nlo+ 0.75 × (nhi−nlo)

Where: nhi= High speed as determined by calculating 70% of the maximum power. The 

highest engine speed where this power value occurs on the power curve is defined as nhi.

nlo= Low speed as determined by calculating 50% of the maximum power. The lowest 

engine speed where this power value occurs on the power curve is defined as nlo.

Maximum power = the maximum observed power calculated according to the engine 

mapping procedures defined in 40 CFR 1065.510.

* * * * *

(f) * * *

(3) If the Maximum Allowable Emission Limit for any point, as calculated under 

paragraphs (f)(1) and (2) of this section, is greater than the applicable Not-to-Exceed 

limit (if within the Not-to-Exceed control area defined in §86.1370(b)), then the 

Maximum Allowable Emission Limit for that point shall be defined as the applicable 

Not-to-Exceed limit.
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* * * * *

115. Newly redesignated § 86.1362 is amended by revising the introductory text and 

adding paragraph (f) to read as follows:

§ 86.1362 Steady-state testing with a ramped-modal cycle.

This section describes how to test engines under steady-state conditions. 

* * * * *

(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.

RMC 

Mode

Time in Mode 

(seconds)

Engine 

Speed1,2

Torque 

(percent) 2,3

1a Steady-state 170 Warm Idle 0

1b Transition 20 Linear Transition Linear Transition

2a Steady-state 170 A 100

2b Transition 20 A Linear Transition

3a Steady-state 102 A 25

3b Transition 20 A Linear Transition

4a Steady-state 100 A 75

4b Transition 20 A Linear Transition

5a Steady-state 103 A 50

5b Transition 20 Linear Transition Linear Transition

6a Steady-state 194 B 100

6b Transition 20 B Linear Transition

7a Steady-state 219 B 25

7b Transition 20 B Linear Transition

8a Steady-state 220 B 75

8b Transition 20 B Linear Transition

9a Steady-state 219 B 50

9b Transition 20 Linear Transition Linear Transition

10a Steady-state 171 C 100

10b Transition 20 C Linear Transition

11a Steady-state 102 C 25

11b Transition 20 C Linear Transition

12a Steady-state 100 C 75

12b Transition 20 C Linear Transition

13a Steady-state 102 C 50

13b Transition 20 Linear Transition Linear Transition

14 Steady-state 168 Warm Idle 0

1

Speed terms are defined in 40 CFR part 1065.

2 Advance from one mode to the next within a 20-second transition phase. During the transition phase, 

command a linear progression from the speed or torque setting of the current mode to the speed or torque 

setting of the next mode.

3 The percent torque is relative to maximum torque at the commanded engine speed.
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116. Newly redesignated § 86.1370 is amended by revising paragraphs (a), (b)(3), 

(b)(6), and (f) introductory text to read as follows:

§ 86.1370 Not-To-Exceed test procedures. 

(a) General. The purpose of this test procedure is to measure in-use emissions of heavyduty diesel engines while operating within a broad range of speed and load points (the 

Not-To-Exceed Control Area) and under conditions which can reasonably be expected to 

be encountered in normal vehicle operation and use. Emission results from this test 

procedure are to be compared to the Not-To-Exceed Limits specified in §86.007–

11(a)(4), or to later Not-To-Exceed Limits. The Not-To-Exceed Limits do not apply for 

engine-starting conditions. Tests conducted using the procedures specified in this subpart 

are considered valid Not-To-Exceed tests (Note: duty cycles and limits on ambient 

conditions do not apply for Not-To-Exceed tests).

(b) * * *

(3) Notwithstanding the provisions of paragraphs (b)(1) and (2) of this section, all 

operating speed and load points with brake specific fuel consumption (BSFC) values 

within 5% of the minimum BSFC value of the engine. For the purposes of this 

requirement, BFSC must be calculated under the general test cell conditions specified in 

40 CFR part 1065. The manufacturer may petition the Administrator at certification to 

exclude such points if the manufacturer can demonstrate that the engine is not expected to 

operate at such points in normal vehicle operation and use. Engines equipped with 

drivelines with multi-speed manual transmissions or automatic transmissions with a finite 

number of gears are not subject to the requirements of this paragraph (b)(3).

* * * * *

(6)(i) For petroleum-fueled diesel cycle engines, the manufacturer may identify particular 

engine-vehicle combinations and may petition the Administrator at certification to 

exclude operating points from the Not-to-Exceed Control Area defined in paragraphs 

(b)(1) through (5) of this section if the manufacturer can demonstrate that the engine is 

not capable of operating at such points when used in the specified engine-vehicle 

combination(s).

(ii) For diesel cycle engines that are not petroleum-fueled, the manufacturer may petition 

the Administrator at certification to exclude operating points from the Not-to-Exceed 

Control Area defined in paragraphs (b)(1) through (5) of this section if the manufacturer 

can demonstrate that the engine is not expected to operate at such points in normal 

vehicle operation and use.

* * * * *

(f) NTE cold temperature operating exclusion. Engines equipped with exhaust gas 

recirculation (EGR) whose operation within the NTE control area specified in paragraph 

(b) of this section when operating during cold temperature conditions as specified in 

paragraph (f)(1) of this section are not subject to the NTE emission limits during the 

specified cold temperature operation conditions.

* * * * *
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Subpart O—[Removed]

117. Subpart O, consisting of §§ 86.1401 through 86.1442, is removed.

Subpart R—[Removed]

118. 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]

119. 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.

120. 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.

(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:
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(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.

* * * * *

121. 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”.
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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 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. 

* * * * *
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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. 

* * * * *

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.

* * * * *

122. 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.

(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 
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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. 

123. 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 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 
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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.

(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 
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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 

emission-related 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.

* * * * *

124. 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 
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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).

(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 
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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. 

(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]

125. Section 86.1807-01 is amended by removing and reserving paragraph (a)(3)(ix).

126. 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 
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(f)(16) of this section. Upon request and approval of the Administrator, manufacturers 

who can demonstrate significant hardship in 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 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 
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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).”

127. 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.

* * * * *

(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. 

* * * * *

128. 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:
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(1) Shall not in its operation or function cause the emission into the ambient air of any 

noxious or toxic substance that would not be emitted in the operation of such vehicle 

without such system, except as specifically permitted by regulation; and

(2) Shall not in its operation, function or malfunction result in any unsafe condition 

endangering the vehicle, its occupants, or persons or property in close proximity to 

the vehicle.

(b) In establishing the physically adjustable range of each adjustable parameter on a new 

motor vehicle, the manufacturer shall ensure that, taking into consideration the 

production tolerances, safe vehicle drivability characteristics are available within that 

range.

(c) Unless otherwise specified, the emission standards of this subpart apply equally for 

certification and for in-use vehicles throughout the specified useful-life period. Also, 

manufacturers must use good engineering judgment to determine that all of a vehicle’s 

emission-related components are designed to operate properly throughout the specified 

useful-life period.

(d) 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.

129. 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 
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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, 

* * * * *

130. 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 
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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.

(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 fleetaverage basis as described in paragraph (b)(5) of this section. Table 1 follows:

Table 1 of §86.1811-17–

Fully Phased-in Tier 3 Exhaust Emission Standards (g/mile)

NMOG+NOx PM CO Formaldehyde

FTP1SFTP FTP US062SFTP FTP

0.030 0.050 0.003 0.010 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.

(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 low-altitude 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 
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§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:

Table 2 of §86.1811-17—

Tier 3 FTP Bin Standards (g/mile)

FEL Name

NMOG+NOx 

FELs for Low 

Altitude 

NMOG+NOx for 

High Altitude

CO for Low and 

High Altitude

Bin 160 0.160 0.160 4.2

Bin 125 0.125 0.160 2.1

Bin 70 0.070 0.105 1.7

Bin 50 0.050 0.070 1.7

Bin 30 0.030 0.050 1.0

Bin 20 0.020 0.030 1.0

Bin 0 0.000 0.000 0.0

(ii) Manufacturers earn a compliance credit of 0.005 g/mile NMOG+NOx for 

vehicles that are certified for a useful life of 150,000 miles or 15 years and that 

are covered by an extended warranty over the same period for all components 

whose failure triggers MIL illumination. Manufacturers may apply the 

compliance credit as follows:

(A) You may 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 fleet-average NMOG+NOx emission level. For any

compliance testing with these vehicles, the applicable FTP bin standard for 

NMOG+NOx is higher than the specified bin standard by the amount of the 

compliance credit. For example, if the official FTP emission result for 

NMOG+NOx is 0.052 g/mile, this qualifies for an FEL of 0.050 g/mile for 

calculating the fleet average and the vehicle is subject to an FTP bin standard 

of 0.055 g/mile. 
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(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 lowaltitude conditions.

(6) The full Tier 3 program includes new emission standards for NMOG+NOx, PM, 

CO, and formaldehyde; it also includes measurement with a new test fuel and a 

longer useful life (for some vehicles). Vehicles meeting all these requirements are 

considered Final Tier 3 vehicles. Vehicles that do not meet all the Tier 3 

requirements are considered Interim Tier 3 vehicles. 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 phase-in percentage for that year 
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(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 

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 fleetaverage 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 
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standards. Fleet-average FTP emission standards decrease through the phase-in 

period as shown in the following table:

Table 3 of §86.1811-17—

Declining Fleet-Average Tier 3 FTP 

Emission Standards for NMOG+NOx (g/mile)

Model Year LDV, LDT11 LDT2, HLDT

2017 20.086 0.101

2018 0.079 0.092

2019 0.072 0.083

2020 0.065 0.074

2021 0.058 0.065

2022 0.051 0.056

2023 0.044 0.047

2024 0.037 0.038

2025 0.030 0.030

1

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 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 fleetaverage 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.

(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 

fleet-average 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 
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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 must also continue to meet the fleetaverage 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. 
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(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 low-altitude 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.

(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 airfuel 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., 
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engine speed, manifold pressure, coolant temperature, air charge temperature, and 

any other parameters). Such calibrations must not unnecessarily reduce emission 

control effectiveness during A/C-on operation when the vehicle is operated under 

conditions that may reasonably be expected during normal operation and use. If 

emission control effectiveness decreases as a result of such calibrations, the 

manufacturer must describe in the Application for Certification the circumstances 

under which this occurs and the reason for using these calibrations.

(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 lowaltitude conditions and high-altitude conditions. Cold temperature CO exhaust 

emission standards apply when measured using the test procedures specified in 

subpart C of this part, as follows:

(i) For 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 
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Page 628 of 903

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 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. 

131. 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 
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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 

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 fleet-average 

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 highaltitude conditions. The sum of diurnal and hot soak measurements may not 

exceed the following fleet-average 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 Low-altitude

conditions

High-altitude 

conditions

LDV, LDT1 0.300 0.65

LDT2 0.400 0.85

HLDT 0.500 1.151

HDV 0.600 1.75

1

1.25 g/test for MDPVs.

(ii) Specify FELs as follows:

(A) You may specify the low-altitude FEL in increments of 0.025 g above or 

below the otherwise applicable Tier 3 diurnal plus hot soak standard, up to the 

maximum values specified in the following table:

Table 2 of §86.1813-17—

Tier 3 FEL Caps for Low-Altitude Testing

Vehicle category FEL caps

LDV 0.500

LLDT 0.650

HLDT 0.900

MDPV 1.000

HDV 1.4

(B) Calculate the FEL for testing at high-altitude conditions based on the 

difference between the low-altitude FEL and the standard. For example, if a 

light-duty vehicle was certified with an FEL of 0.400 g instead of the 0.300 g 

standard, the FEL for testing under high-altitude conditions would be 0.75 g 

(0.65+0.10). 

(iii) Hydrocarbon emissions must not exceed 0.020 g for 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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Page 631 of 903

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.

Table 3 of §86.1813-17—

Default Phase-in Schedule for Tier 3 

Evaporative Emission Standards

Model year

Minimum percentage 

of vehicles subject to 

the Tier 3 standards

2017 40%1,2

2018 60%

2019 60%

2020 80%

2021 80%

2022 100%

1 The phase-in percentage for model year 2017 applies 

only for vehicles at or below 6,000 pounds GVWR.

2 The leak standard specified in paragraph (a)(4) of this 

section does not apply for model year 2017.
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(6) For model year 2017, exclude vehicle sales from California and section 177 states 

from the calculation to demonstrate compliance with the phase-in schedule in 

paragraph (a)(5) or (g) of this section, and from the credit calculation in §86.1860. 

(b) Refueling emissions. 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 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 
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Page 633 of 903

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 higher-emitting version of those vehicle models for sale outside of 

California or the section 177 states. Such vehicles may be certified using carryover 

data under the California program; 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 standard specified in paragraph (a)(4) of this section and the highaltitude 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
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Page 634 of 903

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. 

132. A new §86.1816-18 is added to subpart S to read as follows:

§ 86.1816-18 Emission standards for heavy-duty vehicles.

(a) Applicability and general provisions. This section describes exhaust emission 

standards that apply for model year 2018 and later complete heavy-duty vehicles 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; 
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Page 635 of 903

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-toweight 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:

(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 
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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:

Table 1 of §86.1816-18

Fully Phased-in Tier 3 HDV Exhaust Emission Standards (g/mile)

HDV Class Fleet-average

NMOG+NOx

PM Formaldehyde

FTP FTP HD-SFTP FTP

2b 0.178 0.008 0.01010.006

3 0.247 0.010 0.007 0.006

1

For vehicles with a power-to-weight ratio at or below 0.024 hp/pound that are certified using the 

driving schedule described in paragraph (b)(1)(ii)(B) of this section, the HD-SFTP standard for PM is 

0.007 g/mile instead of the value specified in the table.

(3) The FTP standards specified in this section apply equally for testing at 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. 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:
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Table 2 of §86.1816-18

Tier 3 Bin Standards—Class 2b (g/mile)

FEL 

Name

NMOG+NOx CO

FTP 

(FEL) HD-SFTP1

FTP HD-SFTP

Bin 250 0.250 0.800 6.4 22.0

Bin 200 0.200 0.800 4.2 22.0

Bin 170 0.170 0.450 4.2 12.0

Bin 150 0.150 0.450 3.2 12.0

Bin 020.000 0.000 0.0 0.0

1 Vehicles with a power-to-weight ratio at or below 0.024 hp/pound that are certified using the driving 

schedule described in paragraph (b)(1)(ii)(B) of this section, the following HD-SFTP bin standards for 

NMOG+NOx apply instead of those identified in the table: 0.350 g/mile for Bin 150 and Bin 170; and 

0.550 g/mile for Bin 200 and Bin 250.

2 Vehicles certified to Bin 0 must also meet PM and formaldehyde standards of 0.000 g/mile instead of 

the standards specified in paragraph (b)(2) of this section.

Table 3 of §86.1816-18

Tier 3 Bin Standards—Class 3 (g/mile)

FEL Name

NMOG+NOx CO 

FTP (FEL) HD-SFTP FTP HD-SFTP

Bin 400 0.400 0.550 7.3 6.0

Bin 270 0.270 0.550 4.2 6.0

Bin 230 0.230 0.350 4.2 4.0

Bin 200 0.200 0.350 3.7 4.0

Bin 010.000 0.000 0.0 0.0

1 Vehicles certified to Bin 0 must also meet PM and formaldehyde standards of 0.000 g/mile instead of 

the standards specified in paragraph (b)(2) of this section.

(5) [Reserved]

(6) The full Tier 3 program includes new emission standards for NMOG+NOx, PM, 

CO, and formaldehyde; it also includes measurement with a new test fuel and a 

longer useful life. Vehicles meeting all these requirements are considered Final Tier 

3 vehicles. Vehicles that do not meet all the Tier 3 requirements are considered 

Interim Tier 3 vehicles. The Tier 3 PM standards phase in over several years. Any

vehicles not subject to Tier 3 PM standards during the phase-in period must continue 

to comply with the PM standards in §86.1816-08. Paragraph (b)(7) of this section 

describes how to transition to 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 
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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.

(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)

Model

Year Class 2b Class 3

201610.333 0.548

201710.310 0.508

2018 0.278 0.451

2019 0.253 0.400

2020 0.228 0.349

2021 0.203 0.298

2022 0.178 0.247

1

Fleet-average standards are shown for 2016 and 2017 for purposes 

of voluntary early compliance as described in paragraph (b)(10) of this section.

Table 5 of §86.1816-18

Transitional Tier 3 FTP Bin Standards (g/mile)1

Class FEL 

Name

NMOG NOx PM CO formaldehyde

2b Bin 395 0.195 0.200 0.012 6.4 0.032

Bin 340 0.140 0.200 0.012 6.4 0.032

3 Bin 630 0.230 0.400 0.012 7.3 0.040

Bin 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 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 
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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.

Table 6 of §86.1816-18

Alternative Phase-in Schedule 

Model

Year

Class 2b Class 3

PM Other than 

PM PM Other than PM

2019 40 65% 40 60%

2020 70 77% 70 73%

2021 100 88% 100 87%

2022 100 100% 100 100%

(9) You may not use credits generated from vehicles certified under §86.1816-08 for 

demonstrating compliance with the Tier 3 standards. 

(10) [Reserved] 

(11) You may voluntarily certify your vehicles under this section in model years 2016 

and 2017. If you do this, the fleet-average FTP emission standards for NMOG+NOx 

apply to all your 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 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 low-mileage vehicles by applying the appropriate deterioration factor.

(d) Provisions for Otto-cycle engines. The special provisions described in §86.1811-17(d) 

apply to vehicles with Otto-cycle engines that are certified under this section.

(e) Small-volume manufacturers. Small-volume manufacturers meeting the eligibility
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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. 

133. 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.

* * * * *

134. Section 86.1818-12 is amended by revising paragraph (a) to read as follows:

§ 86.1818-12 Greenhouse gas emission standards for light-duty vehicles, light-duty 

trucks, and medium-duty passenger vehicles.

(a) Applicability. (1) This section contains standards and other regulations applicable to 

the emission of the air pollutant defined as the aggregate group of six greenhouse gases: 

Carbon dioxide, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons, and 

sulfur hexafluoride. This section applies to 2012 and later model year 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 
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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.

* * * * *

135. 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.

136. 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.

* * * * *

137. 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 
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year before the one in which the manufacturer begins its mileage accumulation. The 

manufacturer must also provide information acceptable to the Administrator to indicate 

that the mileage accumulation method is of sufficient design, duration and severity to 

stabilize the permeability of all non-metallic fuel and evaporative system components to 

the mileage accumulation fuel constituents.

* * * * *

(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.

* * * * *

138. 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.

* * * * *

139. Section §86.1826-01 is revised to read as follows:

§ 86.1826-01 Assigned deterioration factors for small-volume manufacturers and 

small-volume test groups.

(a) Applicability. This program is an option available for small-volume manufacturers 

and small-volume test groups as described in §86.1838. 

(b) Determination of deterioration factors. No service accumulation method or 

vehicle/component selection method is required. Deterioration factors for all types of 

regulated emissions are assigned using the provisions in this paragraph (b). A separate 

assigned deterioration factor is required for each durability group. Manufacturers shall 

use good engineering judgment in applying deterioration factors. Manufacturers may use 

assigned deterioration factors that the Administrator determines and prescribes.

(1) The deterioration factors will be the Administrator's estimate, periodically

updated and published in a guidance document, of the 70th percentile deterioration 

factors calculated using the industry-wide database of previously completed 

durability data vehicles or engines used for certification.

(2) The Administrator may use discretion to develop assigned deterioration factors 

using alternative methods if there is insufficient information to calculate an 

appropriate industry-wide deterioration factor (for example: a new engine technology

coupled with a proven emission control system). These methods may include the use 

of assigned deterioration factors based on similar durability vehicles.
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(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.

140. 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.

141. 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 
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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 be based on previous emission tests, development tests, or other 

appropriate information, and good engineering judgment.

* * * * *

142. 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. 
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(3) Test one EDV in each evaporative/refueling family and evaporative/refueling 

emission control system combination using the test procedures in subpart B of this 

part to demonstrate compliance with evaporative and refueling emission standards.

(c) The manufacturer must demonstrate compliance with emission standards at lowaltitude conditions as described in paragraph (b) of this section. For standards that apply 

at high-altitude conditions, the manufacturer may either perform the same tests or provide 

a statement in the application for certification that, based on an engineering evaluation of 

appropriate testing to measure or simulate high-altitude emissions, all vehicles comply

with applicable emission standards at high altitude.

(d) Manufacturers may omit exhaust testing for certification in certain circumstances as 

follows: 

(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.
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(4) Manufacturers may provide a statement in the application for certification that 

vehicles comply with the applicable formaldehyde standard instead of submitting test 

data.

(5) When conducting Selective Enforcement Audit testing, a manufacturer may

petition the Administrator to waive the requirement to measure PM emissions and 

formaldehyde emissions.

(e) Manufacturers may omit evaporative or refueling testing for certification in certain 

circumstances as follows: 

(1) For diesel-fueled vehicles, a manufacturer may provide a statement in the 

application for certification that vehicles comply with the refueling emission standard 

instead of submitting test data.

(2) For vehicles fueled by natural gas, a manufacturer may provide a statement in the 

application for certification that vehicles comply with evaporative emission standards 

instead of submitting test data. 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, canister volume, canister working capacity, fuel tank 

volume, fuel tank geometry, the type of fuel delivery system (return, returnless, 
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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 Californiaspecified 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.

143. Section §86.1837-01 is amended by revising paragraph (a) to read as follows:

§ 86.1837-01 Rounding of emission measurements.

(a) Unless otherwise specified, the results of all emission tests shall be rounded to the 

number of places to the right of the decimal point indicated by expressing the applicable 

emission standard of this subpart to one additional significant figure, in accordance with 

40 CFR 1065.20. 

* * * * *

144. 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 
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procedures to demonstrate compliance with the general standards and specific emission 

requirements contained in this subpart.

(b) Eligibility requirements —(1) Small-volume manufacturers. (i) Optional smallvolume manufacturer certification procedures apply for vehicles produced by 

manufacturers with the following number of combined sales of vehicles subject to 

standards under this subpart in all states and territories of the United States in the 

model year for which certification is sought, including all vehicles and engines 

imported under the provisions of 40 CFR 85.1505 and 85.1509:

(A) 5,000 units for the Tier 3 standards described in §§ 86.1811-17, 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 smallvolume manufacturers after two additional model years. For example, if 

actual sales in model years 2015 through 2017 exceed 5,000 units, the smallvolume 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 (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 smallvolume 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 
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accordance with the criteria identified in paragraphs (b)(2)(ii) through (iv) of this 

section.

(ii) If there are no additional manufacturers in an aggregated relationship meeting 

the provisions of paragraph (b)(3) of this section, then the manufacturer may

certify whole test groups whose total aggregated sales (including heavy-duty

engines) are less than 15,000 units using the small-volume provisions of 

paragraph (c) of this section.

(iii) If there is an aggregated relationship with another manufacturer which 

satisfies the provisions of paragraph (b)(3) of this section, then the following 

provisions shall apply:

(A) If none of the manufacturers own 50 percent or more of another 

manufacturer in the aggregated relationship, then each manufacturer may

certify whole test groups whose total aggregated sales (including heavy-duty

engines) are less than 15,000 units using the small-volume provisions of 

paragraph (c) of this section.

(B) If any of the manufacturers own 50 percent or more of another 

manufacturer in the aggregated relationship, then the limit of 14,999 units 

must be shared among the manufacturers in such a relationship. In total for all 

the manufacturers involved in such a relationship, aggregated sales (including 

heavy-duty engines) of up to 14,999 units may be certified using the smallvolume provisions of paragraph (c) of this section. Only whole test groups 

shall be eligible for small-volume 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 

small-volume 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.
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(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 smallvolume 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 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.

145. 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.

* * * * *
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146. Section 86.1844-01 is amended by revising paragraphs (a), (d)(7), (d)(8), (d)(9), 

(d)(11), and (d)(16)(i) introductory text, removing paragraph (d)(16)(iv), and adding 

paragraph (e)(7) to read as follows:

§ 86.1844-01 Information requirements: Application for certification and submittal 

of information upon request.

(a) All the information listed in this section must be submitted to the Agency according to 

the requirements specified in §86.1843; however, we may ask you to include less 

information than we specify, as long as you keep the specified records. 

* * * * *

(d) * * *

(7) A comprehensive list of all test results, including official certification levels, and the 

applicable intermediate and full useful life emission standards to which the test group is 

to be certified as required in §86.1829–01. 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 

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:
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(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.

* * * * *

147. 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:

§ 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, 
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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 §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.
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(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.

(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 
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procedures described in subpart B of this part, when such test vehicle is tested 

for compliance with applicable evaporative emission and refueling standards 

under this subpart. The test vehicles tested to fulfill the evaporative/refueling 

testing requirement of this paragraph (b)(5)(ii) will be counted when 

determining compliance with the minimum number of vehicles as specified in 

Table S04–06 and Table S04–07 in paragraph (b)(3) of this section for testing 

under paragraph (b)(5)(i) of this section only if the vehicle is also tested for 

exhaust emissions under the requirements of paragraph (b)(5)(i) of this 

section.

(6) Each test vehicle not rejected based on the criteria specified in appendix II to 

this subpart shall be tested in as-received condition. 

(7) A manufacturer may conduct subsequent diagnostic maintenance and/or 

testing of any vehicle. Any such maintenance and/or testing shall be reported to 

the Agency as specified in §86.1847.

(c) High-mileage testing —(1) Test groups. Testing must be conducted for each test 

group.

(2) Vehicle mileage. All test vehicles must have a minimum odometer mileage of 

50,000 miles. At least one vehicle of each test group must have a minimum 

odometer mileage of 105,000 miles or 75 percent of the full useful life mileage, 

whichever is less. See §86.1838–01(c)(2) for small volume manufacturer mileage 

requirements.

(3) Number of test vehicles. For each test group, the minimum number of vehicles 

that must be tested is specified in Table S04–06 and Table S04–07 in paragraph 

(b)(3) of this section. After testing the minimum number of vehicles of a specific 

test group as specified in Table S04–06 and Table S04–07 in paragraph (b)(3) of 

this section, a manufacturer may test additional vehicles upon request and 

approval by the Agency prior to the initiation of the additional testing. Any 

additional testing must be completed within the testing completion requirements 

shown in §86.1845–04(c)(4). The request and Agency approval (if any) shall 

apply to test groups on a case by case basis and apply only to testing under this 

paragraph (c). In addition to any testing that is required under Table S04–06 and 

Table S04–07, a manufacturer shall test one vehicle from each 

evaporative/refueling family for evaporative/refueling emissions. If a 

manufacturer believes it is unable to procure the test vehicles necessary to test the 

required number of vehicles in a test group as specified in Table S04–06 or Table 

S04–07, the manufacturer may request, subject to Administrator approval, a 

decreased sample size for that test 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 
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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 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 
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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.

* * * * *

148. Section 86.1846-01 is revised to read as follows:

§ 86.1846-01 Manufacturer in-use confirmatory testing requirements.

(a) General requirements. (1) Manufacturers must test, or cause testing to be conducted, 

under this section when the emission levels shown by a test group sample from 

testing under §86.1845 exceeds the criteria specified in paragraph (b) of this section. 

The testing required under this section applies separately to each test group and at 

each test point (low and high mileage) that meets the specified criteria. The testing 

requirements apply separately for each model year. These provisions apply to heavyduty 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 

equations prescribed in §86.164. If more than one set of certification SC03 data 
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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 
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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.

(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 Agencydesignated subset) per model year.

(i) Testing plan. Prior to beginning in-use confirmatory testing the manufacturer must, 

after consultation with the Agency, submit a written plan describing the details of the 

vehicle procurement, maintenance, and testing procedures (not otherwise specified by 

regulation) it intends to use. EPA must approve the test plan before the manufacturer 

may start further testing.

(j) Testing a subset. EPA may designate a subset of the test group based on transmission 

type for testing under this section in lieu of testing the entire test group when the results 

for the entire test group from testing conducted under §86.1845 show mean emissions 

and a failure rate which meet these criteria for additional testing.
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149. Section 86.1848-10 is amended by revising paragraph (c)(7) to read as follows:

§ 86.1848-10 Compliance with emission standards for the purpose of certification.

* * * * *

(c) * * *

(7) All certificates of conformity issued are conditional upon compliance with all the 

provisions of §§86.1811 through 86.1816 and 86.1860 through 86.1862 both during and 

after model year production. The manufacturer bears the burden of establishing to the 

satisfaction of the Administrator that the terms and conditions upon which each 

certificate was issued were satisfied. For recall and warranty purposes, vehicles not 

covered by a certificate of conformity will continue to be held to the standards stated or 

referenced in the certificate that otherwise would have applied to the vehicles.

(i) Failure to meet the applicable fleet average standard will be considered to be a failure 

to satisfy the terms and conditions upon which the certificate was issued and the vehicles 

sold in violation of the fleet average standard will not be covered by the certificate.

(ii) Failure to comply fully with the prohibition against selling credits that it has not 

generated or that are not available, as specified in §86.1861, will be considered a failure 

to satisfy the terms and conditions upon which the certificate was issued and the vehicles 

sold in violation of this prohibition will not be covered by the certificate.

(iii) Failure to comply fully with the phase-in requirements of §§86.1811 through 

86.1816 will be considered a failure to satisfy the terms and conditions upon which the 

certificate was issued and the vehicles sold that do not comply with the applicable 

standards, up to the number needed to comply, will not be covered by the certificate.

* * * * *

150. 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:

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.
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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.

(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.

151. A new §86.1861-17 is added to subpart S to read as follows:
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§ 86.1861-17 How do the NMOG+NOx and evaporative emission credit programs 

work?

You may use emission credits for purposes of certification to show compliance with the 

applicable fleet-average NMOG+NOx standards from §§ 86.1811 and 86.1816 and the 

fleet-average evaporative emission standards from §86.1813 as described in 40 CFR part 

1037, subpart H, with certain exceptions and clarifications as specified in this section. 

MDPVs are subject to the same provisions of this section that apply to 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 fleetaverage level is below the standard. Calculate negative emission credits if your fleetaverage value is above the standard. Calculate credits separately for each type of 

standard and for each averaging set. Calculate emission credits using the following 

equation, rounded to the nearest whole number:

Emissioncredit   Volume [ ] Fleet average standard Fleet averagevalue

Where:

Emission credit = The positive or negative credit for each discrete fleet-average 

standard, in units of vehicle-grams per mile for NMOG+NOx and vehicle-grams per 

test for evaporative emissions.

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.
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(c) The credit-deficit provisions 40 CFR 1037.745 apply without modification to the 

NMOG+NOx and evaporative emission standards for Tier 3 vehicles.

(d) The reporting and recordkeeping provisions of §86.1862 apply instead of those 

specified in 40 CFR 1037.730 and 1037.735.

(e) The provisions of 40 CFR 1037.645 do not apply.

152. 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 

fleet-average standard under this subpart must establish and maintain all the 

following information in organized and indexed records for each model year:

(i) Model year.

(ii) Applicable fleet-average standard.

(iii) Calculated fleet-average value.

(iv) All values used in calculating the fleet-average value achieved.

(2) The manufacturer producing any vehicle subject to the provisions in this section 

must keep all the following information for each vehicle:

(i) Model year.

(ii) Applicable fleet-average standard.

(iii) EPA test group.

(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. 
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Manufacturers must keep records readily available as EPA may review them at any 

time.

(4) The Administrator may require the manufacturer to retain additional records or 

submit information not specifically required by this section.

(5) EPA may void ab initio a certificate of conformity for a vehicle certified to 

emission standards as set forth or otherwise referenced in this subpart for which the 

manufacturer fails to retain the records required in this section, to provide such 

information to the Administrator upon request, or to submit the reports required in 

this section in the specified time period.

(c) Reporting. (1) Each manufacturer must submit an annual report. Except as 

provided in paragraph (b)(2) of this section, the annual report must contain, for each 

applicable fleet average standard, the fleet average value achieved, all values required 

to calculate the fleet-average value, the number of credits generated or debits 

incurred, all the values required to calculate the credits or debits, and sufficient 

information to show compliance with all phase-in requirements, if applicable. The 

annual report must also contain the resulting balance of credits or debits.

(2) When a manufacturer calculates compliance with the fleet-average standard using 

the provisions in §86.1860–04(c)(2) or §86.1860-17(f), the annual report must state 

that the manufacturer has elected to use such provision and must contain the fleetaverage 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.
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(6) If EPA or the manufacturer determines that a reporting error occurred on an 

annual report previously submitted to EPA, the manufacturer's credit or debit 

calculations will be recalculated. EPA may void erroneous credits, unless transferred, 

and must adjust erroneous debits. In the case of transferred erroneous credits, EPA 

must adjust the selling manufacturer's credit or debit balance to reflect the sale of 

such credits and any resulting generation of debits.

(d) Notice of opportunity for hearing. Any voiding of the certificate under paragraph 

(a)(6) of this section will be made only after EPA has offered the manufacturer concerned 

an opportunity for a hearing conducted in accordance with §86.614 for light-duty

vehicles and light-duty trucks and with 40 CFR part 1068, subpart G, for heavy-duty

vehicles. 

153. 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.

* * * * *

154. 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.

155. 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 evaporator, etc.). In the first year of such testing, the 

tested vehicle configuration shall be the highest production vehicle configuration within 
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Page 667 of 903

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).

* * * * *

156. 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.

(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 
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schedule specified in this paragraph (b) applies for the portion of the driving schedule 

from 164 to 332 seconds.

Speed Versus Time Sequence

Time 

(sec.)

Speed 

(kph)

164 3.4

165 6.8

166 10.3

167 13.7

168 17.1

169 20.5

170 23.0

171 25.2

172 26.7

173 27.4

174 26.6

175 26.0

176 25.6

177 25.9

178 26.1

179 26.3

180 26.7

181 28.2

182 27.5

183 24.9

184 23.5

185 20.1

186 18.3

187 17.8

188 18.8

189 19.3

190 20.7

191 23.0

192 25.4

193 28.3

194 31.6

195 34.7

196 37.5

197 38.6

198 40.7

199 42.0

200 43.6

201 45.1

202 46.7

203 47.7

204 48.5

205 49.2

206 49.2

207 49.0

208 48.9

209 48.7

210 48.7

211 48.7

212 48.7

213 48.7

214 48.9

215 49.1

216 49.6

217 50.2

218 50.9

219 51.3

220 51.8

221 52.4

222 52.8

223 53.4

224 54.1

225 55.1

226 56.0

227 56.6

228 56.9

229 57.0

230 56.9

231 56.6

232 56.6

233 56.8

234 57.1

235 57.5

236 57.7

237 58.1

238 58.3

239 58.6

240 58.7

241 58.7

242 58.5

243 58.5

244 58.5

245 58.5

246 58.5

247 58.5

248 58.4

249 58.1

250 57.8

251 57.1

252 56.6

253 56.2

254 55.9

255 55.6

256 55.5

257 55.8

258 55.9

259 56.0

260 56.0

261 55.7

262 55.3

263 54.9

264 54.5

265 54.0

266 54.3

267 53.9

268 53.8

269 53.6

270 53.4

271 53.5

272 53.7

273 54.0

274 54.4

275 54.9

276 55.4

277 55.9

278 56.9

279 57.4

280 57.6

281 58.0

282 58.0

283 57.8

284 57.2

285 56.5

286 55.5

287 54.4

288 53.4

289 53.4

290 53.4

291 52.9

292 51.9

293 51.8

294 51.9

295 51.8

296 51.4

297 51.3

298 51.3

299 51.3

300 50.9

301 50.3

302 49.8

303 48.9

304 47.8

305 46.6

306 45.4

307 44.1

308 43.0

309 41.8

310 39.9

311 38.3

312 36.5

313 35.0

314 33.7

315 32.6

316 31.7

317 31.6

318 31.1

319 30.0

320 28.5

321 25.7

322 22.3

323 20.8

324 19.8

325 19.2

326 17.6

327 16.1

328 12.9

329 11.2

330 8.3

331 4.9
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332 1.5

(c) EPA driving schedule for class 3 heavy-duty vehicles. This driving schedule is also 

known as the LA-92 cycle.

Time 

(sec.)

Speed 

(mph)

1 0.0

2 0.0

3 0.0

4 0.0

5 0.0

6 0.0

7 0.0

8 0.0

9 0.0

10 0.0

11 0.0

12 0.0

13 0.0

14 0.0

15 0.0

16 0.0

17 0.0

18 0.0

19 0.0

20 0.0

21 1.2

22 4.2

23 7.3

24 8.8

25 10.8

26 12.3

27 13.1

28 12.3

29 12.3

30 11.5

31 11.5

32 11.1
Page 670 of 903

33 11.1

34 11.1

35 13.1

36 15.0

37 16.9

38 16.9

39 16.1

40 15.7

41 15.4

42 15.0

43 13.8

44 10.8

45 8.4

46 6.1

47 4.2

48 3.5

49 3.5

50 1.5

51 0.0

52 0.0

53 0.0

54 0.0

55 0.0

56 0.0

57 0.0

58 0.0

59 0.0

60 0.0

61 0.0

62 0.0

63 1.2

64 3.5

65 7.7

66 11.1

67 13.8

68 16.5

69 18.4

70 20.4

71 20.7

72 19.6

73 17.3

74 12.3
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75 8.1

76 6.1

77 9.6

78 12.7

79 15.7

80 18.0

81 20.4

82 21.9

83 23.4

84 23.8

85 24.6

86 25.0

87 26.1

88 26.1

89 26.9

90 26.9

91 26.9

92 26.5

93 25.7

94 21.9

95 16.5

96 10.0

97 4.6

98 1.5

99 0.4

100 0.0

101 0.0

102 0.0

103 0.0

104 0.0

105 0.0

106 0.0

107 0.0

108 0.4

109 1.2

110 1.9

111 3.8

112 7.7

113 11.5

114 14.6

115 18.0

116 21.5
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117 25.0

118 28.4

119 30.7

120 31.9

121 32.3

122 32.3

123 31.9

124 30.3

125 28.0

126 24.2

127 20.0

128 16.1

129 11.5

130 8.1

131 5.0

132 3.5

133 1.9

134 0.0

135 0.0

136 0.0

137 0.0

138 0.0

139 0.0

140 0.0

141 0.0

142 0.0

143 1.5

144 6.9

145 12.7

146 16.5

147 20.0

148 23.0

149 25.7

150 28.0

151 30.7

152 32.6

153 34.2

154 35.3

155 36.9

156 36.9

157 37.2

158 37.6
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159 37.6

160 37.6

161 37.2

162 37.2

163 36.9

164 36.5

165 36.5

166 34.9

167 33.4

168 31.9

169 29.2

170 25.0

171 25.0

172 26.1

173 27.6

174 29.2

175 31.1

176 32.3

177 34.2

178 34.9

179 35.7

180 36.5

181 36.9

182 36.9

183 37.2

184 37.6

185 37.2

186 37.6

187 38.0

188 38.4

189 39.2

190 39.6

191 39.9

192 40.7

193 40.3

194 41.1

195 41.1

196 40.7

197 31.9

198 23.9

199 15.9

200 7.9
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201 2.7

202 0.4

203 0.4

204 2.7

205 3.8

206 3.8

207 1.5

208 0.0

209 0.0

210 0.0

211 0.0

212 0.0

213 0.0

214 0.0

215 0.0

216 0.0

217 0.0

218 0.0

219 0.0

220 0.0

221 0.0

222 0.0

223 0.0

224 0.0

225 0.0

226 0.0

227 0.0

228 0.0

229 0.0

230 0.0

231 0.0

232 0.0

233 0.0

234 0.0

235 0.0

236 0.0

237 0.0

238 1.5

239 5.0

240 8.8

241 11.5

242 14.2
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243 15.4

244 16.1

245 16.1

246 16.9

247 16.5

248 16.9

249 18.0

250 19.2

251 20.4

252 20.4

253 21.1

254 21.1

255 22.3

256 23.0

257 23.8

258 24.2

259 24.6

260 25.0

261 25.7

262 25.7

263 26.5

264 27.6

265 28.4

266 29.2

267 30.3

268 31.1

269 31.1

270 30.7

271 31.1

272 29.6

273 29.2

274 29.2

275 28.8

276 28.0

277 23.0

278 21.1

279 21.5

280 20.7

281 20.7

282 19.6

283 16.5

284 13.1
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285 9.6

286 7.3

287 3.8

288 0.8

289 0.0

290 0.0

291 0.0

292 0.0

293 0.0

294 0.0

295 0.0

296 0.0

297 0.0

298 0.0

299 0.0

300 0.0

301 0.0

302 0.0

303 0.0

304 0.0

305 0.0

306 0.0

307 0.0

308 0.0

309 0.0

310 0.0

311 0.0

312 0.0

313 0.4

314 2.7

315 7.3

316 11.5

317 15.4

318 18.4

319 20.7

320 24.2

321 26.9

322 29.6

323 31.1

324 32.6

325 33.8

326 34.9
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327 36.9

328 39.2

329 41.1

330 43.0

331 43.8

332 44.5

333 45.3

334 45.3

335 44.9

336 44.5

337 43.8

338 43.4

339 42.6

340 41.9

341 41.5

342 40.7

343 40.3

344 41.1

345 41.5

346 42.6

347 43.4

348 44.2

349 44.9

350 45.7

351 46.5

352 46.8

353 47.2

354 48.0

355 47.6

356 48.4

357 48.0

358 47.2

359 46.1

360 45.7

361 44.9

362 44.2

363 43.8

364 44.5

365 44.9

366 45.3

367 46.5

368 48.0
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369 48.8

370 49.5

371 49.9

372 49.9

373 49.9

374 49.5

375 49.5

376 48.8

377 48.8

378 48.8

379 48.4

380 48.8

381 49.5

382 50.3

383 50.7

384 51.8

385 52.6

386 53.4

387 54.1

388 55.3

389 55.3

390 56.1

391 56.4

392 56.4

393 56.4

394 57.2

395 56.8

396 57.6

397 57.6

398 57.6

399 58.0

400 58.0

401 58.4

402 58.4

403 58.8

404 59.1

405 58.8

406 58.8

407 58.0

408 58.0

409 57.6

410 57.6
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411 57.6

412 57.6

413 57.6

414 59.1

415 59.5

416 59.9

417 60.3

418 60.3

419 61.1

420 60.3

421 59.9

422 59.5

423 59.1

424 59.1

425 59.5

426 59.5

427 59.5

428 59.9

429 60.3

430 60.7

431 60.7

432 61.4

433 61.8

434 61.8

435 61.8

436 61.8

437 61.1

438 60.7

439 60.3

440 60.3

441 60.3

442 59.5

443 58.8

444 59.1

445 58.8

446 58.8

447 58.8

448 58.4

449 58.0

450 58.0

451 58.0

452 58.4
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453 59.1

454 59.5

455 59.9

456 59.9

457 60.3

458 61.1

459 61.1

460 61.1

461 61.4

462 61.4

463 61.1

464 60.7

465 59.9

466 59.1

467 59.1

468 59.1

469 59.9

470 59.5

471 59.9

472 58.8

473 58.0

474 57.6

475 56.8

476 56.1

477 55.3

478 54.1

479 52.6

480 49.2

481 46.1

482 43.0

483 37.2

484 29.6

485 21.5

486 16.5

487 15.7

488 18.4

489 21.5

490 25.0

491 27.3

492 29.2

493 30.7

494 31.5
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495 31.1

496 31.1

497 30.3

498 30.0

499 30.0

500 29.6

501 30.0

502 28.8

503 28.8

504 28.0

505 28.4

506 28.0

507 28.4

508 28.4

509 28.8

510 28.4

511 28.4

512 28.0

513 26.5

514 24.2

515 22.7

516 20.4

517 17.7

518 15.7

519 13.1

520 10.8

521 8.4

522 7.3

523 5.0

524 3.8

525 3.5

526 1.9

527 0.8

528 0.0

529 0.0

530 0.0

531 0.8

532 1.9

533 3.8

534 6.9

535 9.6

536 11.1
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537 11.1

538 10.4

539 8.8

540 9.2

541 10.0

542 10.4

543 10.4

544 5.4

545 1.9

546 0.0

547 0.0

548 0.0

549 0.0

550 0.0

551 0.0

552 0.0

553 0.0

554 0.0

555 0.0

556 0.0

557 0.0

558 0.0

559 0.0

560 0.0

561 0.0

562 0.0

563 0.0

564 0.0

565 0.0

566 0.0

567 0.0

568 0.0

569 0.0

570 0.0

571 0.0

572 0.4

573 1.5

574 3.5

575 6.1

576 10.4

577 14.2

578 16.9
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579 19.2

580 20.0

581 21.5

582 23.4

583 24.6

584 24.2

585 20.0

586 16.9

587 13.4

588 13.4

589 15.7

590 18.4

591 21.1

592 23.4

593 25.3

594 27.6

595 28.8

596 30.3

597 30.7

598 31.5

599 31.1

600 31.1

601 30.3

602 30.3

603 30.3

604 30.7

605 31.1

606 32.3

607 32.6

608 32.6

609 32.6

610 31.1

611 26.9

612 22.3

613 18.0

614 13.8

615 9.6

616 4.6

617 6.1

618 10.0

619 14.2

620 17.3
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621 20.0

622 21.5

623 22.3

624 22.3

625 22.3

626 22.3

627 23.0

628 23.0

629 22.7

630 22.3

631 21.9

632 22.7

633 23.8

634 25.0

635 25.3

636 25.7

637 26.5

638 26.9

639 27.3

640 28.0

641 29.2

642 30.0

643 30.0

644 29.6

645 29.6

646 28.8

647 28.4

648 28.0

649 27.3

650 25.7

651 24.6

652 25.0

653 26.5

654 28.0

655 29.6

656 30.7

657 32.3

658 33.0

659 34.2

660 34.6

661 35.3

662 36.1
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663 36.1

664 36.9

665 36.9

666 37.6

667 37.6

668 38.4

669 38.0

670 37.6

671 37.6

672 37.2

673 36.9

674 36.1

675 35.7

676 36.1

677 35.7

678 35.7

679 35.7

680 36.1

681 36.1

682 35.7

683 35.7

684 34.9

685 34.6

686 34.2

687 33.8

688 33.4

689 33.0

690 30.3

691 29.2

692 28.4

693 25.0

694 21.1

695 16.9

696 13.4

697 13.1

698 12.3

699 12.7

700 15.7

701 19.2

702 22.3

703 24.6

704 25.7
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705 26.5

706 26.5

707 26.9

708 27.3

709 27.3

710 27.6

711 28.4

712 28.8

713 28.8

714 29.2

715 28.8

716 28.8

717 28.0

718 28.0

719 27.6

720 26.5

721 24.6

722 20.7

723 16.5

724 15.0

725 14.2

726 14.2

727 13.8

728 13.8

729 11.9

730 8.4

731 4.2

732 1.2

733 0.0

734 0.0

735 0.0

736 0.0

737 0.0

738 0.0

739 0.0

740 0.0

741 0.0

742 0.0

743 0.0

744 0.0

745 0.0

746 0.0
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747 0.0

748 0.0

749 0.0

750 0.0

751 0.0

752 0.0

753 0.0

754 0.0

755 0.0

756 0.0

757 0.0

758 0.0

759 0.0

760 0.0

761 0.0

762 0.0

763 1.5

764 5.4

765 9.2

766 11.5

767 14.6

768 17.3

769 19.2

770 21.1

771 20.7

772 20.7

773 19.6

774 18.4

775 16.9

776 16.9

777 16.5

778 16.9

779 16.9

780 16.9

781 17.3

782 19.2

783 20.4

784 21.1

785 22.3

786 22.3

787 22.7

788 22.3
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789 22.7

790 22.3

791 23.8

792 25.7

793 27.6

794 29.6

795 30.0

796 29.2

797 27.6

798 25.0

799 23.8

800 23.4

801 24.2

802 23.4

803 23.0

804 20.4

805 18.8

806 17.3

807 15.0

808 13.1

809 9.2

810 6.9

811 4.6

812 4.6

813 4.6

814 4.2

815 5.4

816 4.6

817 3.5

818 2.3

819 2.3

820 1.9

821 3.1

822 6.1

823 4.6

824 2.7

825 2.3

826 2.3

827 3.1

828 4.2

829 3.5

830 3.8
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831 4.2

832 3.5

833 3.5

834 3.5

835 4.6

836 5.8

837 3.5

838 0.8

839 3.5

840 3.8

841 2.3

842 0.0

843 1.2

844 6.9

845 13.8

846 18.8

847 23.8

848 27.3

849 30.7

850 33.8

851 37.6

852 40.7

853 43.8

854 46.1

855 48.0

856 49.5

857 51.5

858 53.0

859 54.5

860 55.7

861 56.8

862 58.0

863 59.1

864 60.3

865 61.1

866 61.8

867 61.8

868 61.8

869 61.8

870 62.6

871 63.4

872 63.0
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873 63.0

874 62.6

875 61.8

876 61.8

877 62.2

878 62.2

879 62.6

880 63.7

881 64.5

882 64.9

883 66.0

884 66.0

885 66.8

886 66.4

887 66.8

888 67.2

889 66.4

890 66.4

891 66.0

892 65.7

893 65.7

894 66.4

895 66.0

896 65.7

897 65.3

898 65.3

899 64.5

900 64.5

901 64.1

902 63.7

903 63.7

904 63.7

905 64.5

906 64.5

907 64.9

908 64.5

909 64.1

910 64.9

911 65.3

912 65.3

913 65.3

914 64.1
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915 63.4

916 63.0

917 63.4

918 64.1

919 64.9

920 65.3

921 64.5

922 64.1

923 63.4

924 63.7

925 63.4

926 63.4

927 63.4

928 63.4

929 63.7

930 64.5

931 65.3

932 64.9

933 63.7

934 63.0

935 59.9

936 55.3

937 50.7

938 49.2

939 48.0

940 46.1

941 44.2

942 41.1

943 39.9

944 36.1

945 32.6

946 29.2

947 24.6

948 20.7

949 19.2

950 16.5

951 15.0

952 11.9

953 9.6

954 8.4

955 5.8

956 1.2
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957 0.0

958 0.0

959 0.0

960 1.2

961 3.1

962 5.0

963 8.4

964 11.5

965 14.6

966 16.9

967 18.8

968 21.1

969 23.8

970 26.5

971 28.0

972 29.6

973 30.7

974 32.6

975 34.2

976 35.3

977 36.1

978 36.9

979 38.0

980 38.0

981 38.0

982 38.0

983 38.0

984 37.2

985 36.9

986 36.1

987 35.7

988 34.9

989 34.9

990 33.8

991 31.5

992 28.8

993 25.7

994 24.6

995 23.4

996 22.3

997 21.5

998 20.0
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999 20.0

1000 19.2

1001 19.2

1002 18.0

1003 11.9

1004 6.9

1005 2.7

1006 0.8

1007 0.4

1008 0.0

1009 0.0

1010 0.0

1011 0.0

1012 0.0

1013 0.0

1014 0.0

1015 0.0

1016 0.0

1017 0.0

1018 0.0

1019 0.0

1020 0.0

1021 0.0

1022 0.0

1023 0.4

1024 2.7

1025 6.1

1026 9.2

1027 11.5

1028 14.2

1029 16.1

1030 18.0

1031 20.0

1032 21.5

1033 23.0

1034 24.2

1035 25.0

1036 25.7

1037 26.9

1038 27.6

1039 27.6

1040 28.4
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1041 29.2

1042 29.2

1043 30.0

1044 29.6

1045 29.6

1046 28.8

1047 28.0

1048 23.8

1049 18.8

1050 11.9

1051 6.1

1052 1.5

1053 1.5

1054 4.2

1055 8.1

1056 10.4

1057 13.1

1058 15.4

1059 18.0

1060 20.4

1061 23.0

1062 25.3

1063 27.3

1064 28.8

1065 30.3

1066 31.1

1067 32.3

1068 31.9

1069 32.3

1070 31.9

1071 31.1

1072 28.8

1073 25.0

1074 22.7

1075 18.8

1076 15.4

1077 13.4

1078 11.9

1079 8.8

1080 5.0

1081 1.9

1082 2.3
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1083 2.7

1084 3.5

1085 6.5

1086 10.8

1087 13.8

1088 16.1

1089 18.4

1090 20.4

1091 21.9

1092 21.9

1093 20.7

1094 17.3

1095 13.1

1096 9.6

1097 8.8

1098 10.8

1099 12.7

1100 14.2

1101 14.6

1102 13.1

1103 11.1

1104 11.1

1105 11.1

1106 13.1

1107 15.7

1108 18.4

1109 20.7

1110 23.8

1111 25.7

1112 28.0

1113 30.0

1114 31.1

1115 32.3

1116 34.2

1117 35.7

1118 36.9

1119 38.8

1120 40.3

1121 41.5

1122 42.2

1123 43.0

1124 43.8
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1125 43.8

1126 43.4

1127 43.0

1128 42.2

1129 41.9

1130 41.5

1131 41.9

1132 41.9

1133 41.9

1134 42.2

1135 42.6

1136 42.6

1137 42.6

1138 42.6

1139 42.6

1140 42.6

1141 42.6

1142 42.2

1143 43.0

1144 43.4

1145 43.0

1146 42.6

1147 41.9

1148 40.7

1149 36.9

1150 32.6

1151 28.0

1152 23.4

1153 18.4

1154 14.6

1155 12.3

1156 9.2

1157 5.8

1158 1.9

1159 0.4

1160 0.0

1161 0.0

1162 0.0

1163 0.0

1164 0.0

1165 0.4

1166 4.2
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1167 9.2

1168 11.9

1169 14.2

1170 15.7

1171 15.0

1172 14.2

1173 13.4

1174 13.8

1175 14.6

1176 14.6

1177 14.2

1178 16.1

1179 15.7

1180 15.7

1181 14.6

1182 13.1

1183 10.0

1184 7.3

1185 3.5

1186 0.8

1187 0.0

1188 0.0

1189 0.0

1190 0.0

1191 0.4

1192 2.7

1193 7.3

1194 11.5

1195 15.4

1196 19.2

1197 21.9

1198 23.8

1199 25.0

1200 26.1

1201 27.3

1202 28.8

1203 30.0

1204 29.6

1205 29.6

1206 28.8

1207 26.1

1208 22.3
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1209 19.2

1210 16.5

1211 12.7

1212 9.6

1213 6.9

1214 4.2

1215 2.3

1216 0.8

1217 0.0

1218 0.0

1219 0.0

1220 0.0

1221 0.0

1222 0.0

1223 0.0

1224 0.0

1225 0.0

1226 0.0

1227 0.0

1228 0.0

1229 0.0

1230 0.0

1231 0.0

1232 0.0

1233 0.0

1234 0.0

1235 0.0

1236 0.0

1237 0.0

1238 0.0

1239 0.0

1240 3.5

1241 10.4

1242 15.4

1243 17.3

1244 17.3

1245 18.4

1246 21.5

1247 24.6

1248 27.3

1249 30.0

1250 31.5
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1251 31.9

1252 32.6

1253 33.4

1254 34.9

1255 36.5

1256 37.6

1257 39.2

1258 40.3

1259 40.7

1260 41.1

1261 40.7

1262 40.7

1263 40.7

1264 41.5

1265 42.6

1266 43.0

1267 44.5

1268 45.3

1269 45.3

1270 44.9

1271 43.4

1272 40.3

1273 38.0

1274 36.1

1275 36.5

1276 38.0

1277 39.2

1278 40.7

1279 42.2

1280 43.4

1281 44.9

1282 45.7

1283 46.1

1284 46.8

1285 46.5

1286 46.5

1287 46.5

1288 46.1

1289 46.1

1290 46.1

1291 46.8

1292 47.6
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1293 48.0

1294 48.4

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1296 48.0

1297 47.2

1298 46.5

1299 46.8

1300 47.2

1301 48.4

1302 48.4

1303 48.8

1304 48.4

1305 47.6

1306 46.5

1307 44.2

1308 42.2

1309 41.5

1310 41.1

1311 40.7

1312 40.3

1313 39.6

1314 39.2

1315 38.8

1316 38.0

1317 37.6

1318 37.2

1319 36.5

1320 34.6

1321 31.5

1322 29.6

1323 29.2

1324 28.8

1325 28.8

1326 28.0

1327 28.0

1328 28.4

1329 29.6

1330 30.0

1331 30.3

1332 29.2

1333 26.5

1334 25.3
Page 701 of 903

1335 25.0

1336 24.6

1337 24.6

1338 25.3

1339 26.1

1340 27.3

1341 28.4

1342 29.2

1343 29.2

1344 29.6

1345 30.0

1346 31.1

1347 32.6

1348 33.8

1349 34.6

1350 34.9

1351 34.6

1352 34.9

1353 34.6

1354 34.9

1355 34.9

1356 34.9

1357 34.2

1358 33.8

1359 32.6

1360 31.5

1361 30.0

1362 28.8

1363 27.3

1364 23.8

1365 23.0

1366 23.0

1367 22.3

1368 20.4

1369 18.8

1370 17.7

1371 16.1

1372 14.6

1373 12.7

1374 11.1

1375 9.2

1376 8.8
Page 702 of 903

1377 7.3

1378 6.1

1379 5.0

1380 4.2

1381 3.5

1382 2.7

1383 2.3

1384 1.5

1385 1.2

1386 0.0

1387 1.2

1388 4.2

1389 7.3

1390 8.8

1391 10.8

1392 12.3

1393 13.1

1394 12.3

1395 12.3

1396 11.5

1397 11.5

1398 11.1

1399 11.1

1400 11.1

1401 13.1

1402 15.0

1403 16.9

1404 16.9

1405 16.1

1406 15.7

1407 15.4

1408 15.0

1409 13.8

1410 10.8

1411 8.4

1412 6.1

1413 4.2

1414 3.5

1415 3.5

1416 1.5

1417 0.0

1418 0.0
Page 703 of 903

1419 0.0

1420 0.0

1421 0.0

1422 0.0

1423 0.0

1424 0.0

1425 0.0

1426 0.0

1427 0.0

1428 0.0

1429 0.0

1430 0.0

1431 0.0

1432 0.0

1433 0.0

1434 0.0

1435 0.0

1436 0.0

1437 0.0

1438 0.0

1439 0.0

1440 0.0

1441 0.0

1442 0.0

1443 0.0

1444 0.0

1445 0.0

1446 0.0

1447 0.0

1448 0.0

1449 0.0

1450 0.0

1451 0.0

1452 0.0

1453 0.0

1454 0.0

1455 0.0

1456 1.2

1457 4.2

1458 7.3

1459 8.8

1460 10.8
Page 704 of 903

1461 12.3

1462 13.1

1463 12.3

1464 12.3

1465 11.5

1466 11.5

1467 11.1

1468 11.1

1469 11.1

1470 13.1

1471 15.0

1472 16.9

1473 16.9

1474 16.1

1475 15.7

1476 15.4

1477 15.0

1478 13.8

1479 10.8

1480 8.4

1481 6.1

1482 4.2

1483 3.5

1484 3.5

1485 1.5

1486 0.0

1487 0.0

1488 0.0

1489 0.0

1490 0.0

1491 0.0

1492 0.0

1493 0.0

1494 0.0

1495 0.0

1496 0.0

1497 0.0

1498 1.2

1499 3.5

1500 7.7

1501 11.1

1502 13.8
Page 705 of 903

1503 16.5

1504 18.4

1505 20.4

1506 20.7

1507 19.6

1508 17.3

1509 12.3

1510 8.1

1511 6.1

1512 9.6

1513 12.7

1514 15.7

1515 18.0

1516 20.4

1517 21.9

1518 23.4

1519 23.8

1520 24.6

1521 25.0

1522 26.1

1523 26.1

1524 26.9

1525 26.9

1526 26.9

1527 26.5

1528 25.7

1529 21.9

1530 16.5

1531 10.0

1532 4.6

1533 1.5

1534 0.4

1535 0.0

1536 0.0

1537 0.0

1538 0.0

1539 0.0

1540 0.0

1541 0.0

1542 0.0

1543 0.4

1544 1.2
Page 706 of 903

1545 1.9

1546 3.8

1547 7.7

1548 11.5

1549 14.6

1550 18.0

1551 21.5

1552 25.0

1553 28.4

1554 30.7

1555 31.9

1556 32.3

1557 32.3

1558 31.9

1559 30.3

1560 28.0

1561 24.2

1562 20.0

1563 16.1

1564 11.5

1565 8.1

1566 5.0

1567 3.5

1568 1.9

1569 0.0

1570 0.0

1571 0.0

1572 0.0

1573 0.0

1574 0.0

1575 0.0

1576 0.0

1577 0.0

1578 1.5

1579 6.9

1580 12.7

1581 16.5

1582 20.0

1583 23.0

1584 25.7

1585 28.0

1586 30.7
Page 707 of 903

1587 32.6

1588 34.2

1589 35.3

1590 36.9

1591 36.9

1592 37.2

1593 37.6

1594 37.6

1595 37.6

1596 37.2

1597 37.2

1598 36.9

1599 36.5

1600 36.5

1601 34.9

1602 33.4

1603 31.9

1604 29.2

1605 25.0

1606 25.0

1607 26.1

1608 27.6

1609 29.2

1610 31.1

1611 32.3

1612 34.2

1613 34.9

1614 35.7

1615 36.5

1616 36.9

1617 36.9

1618 37.2

1619 37.6

1620 37.2

1621 37.6

1622 38.0

1623 38.4

1624 39.2

1625 39.6

1626 39.9

1627 40.7

1628 40.3
Page 708 of 903

1629 41.1

1630 41.1

1631 40.7

1632 31.9

1633 23.9

1634 15.9

1635 7.9

1636 2.7

1637 0.4

1638 0.4

1639 2.7

1640 3.8

1641 3.8

1642 1.5

1643 0.0

1644 0.0

1645 0.0

1646 0.0

1647 0.0

1648 0.0

1649 0.0

1650 0.0

1651 0.0

1652 0.0

1653 0.0

1654 0.0

1655 0.0

1656 0.0

1657 0.0

1658 0.0

1659 0.0

1660 0.0

1661 0.0

1662 0.0

1663 0.0

1664 0.0

1665 0.0

1666 0.0

1667 0.0

1668 0.0

1669 0.0

1670 0.0
Page 709 of 903

1671 0.0

1672 0.0

1673 1.5

1674 5.0

1675 8.8

1676 11.5

1677 14.2

1678 15.4

1679 16.1

1680 16.1

1681 16.9

1682 16.5

1683 16.9

1684 18.0

1685 19.2

1686 20.4

1687 20.4

1688 21.1

1689 21.1

1690 22.3

1691 23.0

1692 23.8

1693 24.2

1694 24.6

1695 25.0

1696 25.7

1697 25.7

1698 26.5

1699 27.6

1700 28.4

1701 29.2

1702 30.3

1703 31.1

1704 31.1

1705 30.7

1706 31.1

1707 29.6

1708 29.2

1709 29.2

1710 28.8

1711 28.0

1712 23.0
Page 710 of 903

1713 21.1

1714 21.5

1715 20.7

1716 20.7

1717 19.6

1718 16.5

1719 13.1

1720 9.6

1721 7.3

1722 3.8

1723 0.8

1724 0.0

1725 0.0

1726 0.0

1727 0.0

1728 0.0

1729 0.0

1730 0.0

1731 0.0

1732 0.0

1733 0.0

1734 0.0

1735 0.0

(d) 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 through Appendix XVIII to Part 86—[Removed]

157. Appendix XIII through Appendix XVIII to Part 86 are removed.

PART 600—FUEL ECONOMY AND GREENHOUSE GAS EXHAUST 

EMISSIONS OF MOTOR VEHICLES

158. 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

159. The heading for subpart A is revised as set forth above.

160. Section 600.011 is amended by revising paragraphs (b), (c)(2), and (c)(3) to read 

as follows:

§ 600.011 Incorporation by reference.

* * * * *
Page 711 of 903

(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, 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]

161. 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 
Page 712 of 903

may approve the use of an earlier version of SAE J1634 for carryover vehicles, or if you 

show that it is equivalent for your vehicle.

* * * * *

(b) Determine performance values for hybrid electric vehicles that have no plug-in 

capability as specified in §§ 600.210 and 600.311 using the procedures for chargesustaining operation from SAE J1711 (incorporated by reference in § 600.011). We may

approve alternate measurement procedures with respect to these vehicles if that is 

necessary or appropriate for meeting the objectives of this part.

(c) Determine performance values for hybrid electric vehicles that have plug-in capability

as specified in §§ 600.210 and 600.311 using the procedures of SAE J1711 (incorporated 

by reference in § 600.011), with the following clarifications and modifications:

(1) To determine fuel economy and CREE values to demonstrate compliance with CAFE 

and GHG standards, calculate composite values representing combined operation during 

charge-depleting and charge-sustaining operation using the following utility factors 

except as specified in this paragraph (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]

162. 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]

163. Subpart D is amended by removing the following sections: 600.302-08, 600.311-

08.

164. Section 600.311-12 is amended by revising paragraph (g) to read as follows:

§ 600.311-12 Determination of values for fuel economy labels.

* * * * *

(g) Smog rating. Establish a rating for exhaust emissions other than CO2 based on the 

applicable emission standards for the appropriate model year as shown in Tables 1 

through 3 of this section. For Independent Commercial Importers that import vehicles not 

subject to Tier 2 or Tier 3 emission standards, the vehicle's smog rating is 1. Similarly, if 

a manufacturer certifies vehicles to emission standards that are less stringent than all the 

identified standards for any reason, the vehicle’s smog rating is 1. If EPA or California 

emission standards change in the future, we may revise the emission levels corresponding 

to each rating for future model years as appropriate to reflect the changed standards. If 

this occurs, we would publish the revised ratings as described in §600.302–12(k), 

allowing sufficient lead time to make the changes; we would also expect to initiate a 

rulemaking to update the smog rating in the regulation.
Page 713 of 903

Table 1 of §600.311–12—Criteria for Establishing 

Smog Rating for Model Year 2025 and Later

Rating U.S. EPA Tier 3 Emission 

Standard

California Air Resources Board 

LEV III Emission Standard

1 Bin 160 LEV 160

2 Bin 125 ULEV125

4 Bin 70 ULEV70

5 Bin 50 ULEV50

6 Bin 30 SULEV30

7 Bin 20 SULEV20

8 — TZEV

10 Bin 0 ZEV

Table 2 of §600.311–12—Criteria for Establishing 

Smog Rating for Model Years 2018 -2024

Rating U.S. EPA Tier 3 

Emission Standard

U.S EPA Tier 2 

Emission Standard

California Air Resources Board 

LEV III Emission Standard

1 Bin 160 Bin 5 through Bin 8 LEV 160

3 Bin 125 Bin 4 ULEV125

5 Bin 70 Bin 3 ULEV70

6 Bin 50 — ULEV50

7 Bin 30 Bin 2 SULEV30

8 Bin 20 — SULEV20

9 — — TZEV

10 Bin 0 Bin 1 ZEV

Table 3 of §600.311–12—Criteria for Establishing 

Smog Rating through Model Year 2017

Rating

U.S. EPA Tier 2 

Emission Standard

California Air Resources Board 

LEV II Emission Standard

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]

165. Subpart F is amended by removing the following sections: 600.507-08, 600.509-

08, 600.510-08, 600.512-08.
Page 714 of 903

Appendix IV and Appendix V —[Removed]

166. 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

167. The authority citation for part 1036 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart B—[Amended]

168. Section 1036.115 is amended by revising paragraph (b) to read as follows:

§ 1036.115 Other requirements.

* * * * *

(b) You must design and produce your engines to comply with evaporative emission 

standards as follows:

(1) For complete heavy-duty vehicles you produce, you must certify the vehicles to 

emission standards as specified in 40 CFR 1037.103.

(2) For incomplete heavy-duty vehicles, and for engines used in vehicles you do not 

produce, you do not need to certify your engines to evaporative emission standards or 

otherwise meet those standards. However, vehicle manufacturers certifying their 

vehicles with your engines may depend on you to produce your engines according to 

their specifications. Also, your engines must meet applicable exhaust emission 

standards in the installed configuration.

PART 1037—CONTROL OF EMISSIONS FROM NEW HEAVY-DUTY MOTOR 

VEHICLES 

169. The authority citation for part 86 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart B – [Amended]

170. Section §1037.101 is amended by revising paragraph (b)(4) and adding paragraph 

(c)(3) to read as follows:

§ 1037.101 Overview of emission standards for heavy-duty vehicles.

* * * * *

(b) * * *

(4) Fuel evaporative emissions. These requirements are described in 40 CFR part 86 and 

§1037.103.

(c) * * *

(3) For evaporative and refueling emissions, vehicles are regulated based on the type of 

fuel they use. Vehicles fueled with volatile liquid fuels or gaseous fuels are subject to 

evaporative emission standards. Vehicles up to a certain size that are fueled with 

gasoline, diesel fuel, ethanol, methanol, or LPG are subject to refueling emission 

standards. 

171. A new §1037.103 is added to read as follows:
Page 715 of 903

§ 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 heavy-duty 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 

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 
Page 716 of 903

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.

172. 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]

173. Section 1037.230 is amended by revising paragraph (e) to read as follows:

§ 1037.230 Vehicle families, sub-families, and configurations.

* * * * *

(e) Divide your vehicles that are subject to evaporative emission standards into groups of 

vehicles with similar physical features expected to affect evaporative emissions. Group 

vehicles in the same evaporative emission family if they are the same in all the following 

aspects, unless we approve a better way of grouping vehicles into families that have 

similar emission control characteristics:

(1) Method of vapor storage, including the number of vapor storage devices, the 

working material, and the total working capacity of vapor storage (as determined 

under 40 CFR 86.132-96(h)(1)(iv)). You may consider the working capacity to be 

the same if the values differ by 20 grams or less.

(2) Method of purging stored vapors.

(3) Material for liquid and vapor fuel lines.

* * * * *

174. 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 
Page 717 of 903

analysis is not adequate to show that all the vehicles in the family will comply with 

applicable emission standards throughout the useful life, or if a test result from an 

emission-data vehicle representing the family exceeds an emission standard.

(c) To compare emission levels with emission standards, apply deterioration factors to the 

measured emission levels. Establish an additive deterioration factor based on an 

engineering analysis that takes into account the expected aging from in-use vehicles. 

(d) Apply the deterioration factor to the official emission result, as described in paragraph 

(c) of this section, then round the adjusted figure to the same number of decimal places as 

the emission standard. Compare the rounded emission levels to the emission standard for 

each emission-data vehicle. 

(e) Your analysis to demonstrate compliance with emission standards must take into 

account your design strategy for vehicles that require testing. Specifically, vehicles 

above 14,000 pounds GVWR are presumed to need the same technologies that are 

required for heavy-duty vehicles at or below 14,000 pounds GVWR. Similarly, your 

analysis to establish a deterioration factor must take into account your testing to establish 

deterioration factors for smaller vehicles.

Subpart F—[Amended]

175. 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. 

* * * * *

176. 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.
Page 718 of 903

(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. 

Part 1065—ENGINE-TESTING PROCEDURES

177. The authority citation for part 1065 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart A—[Amended]

178. 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.

179. 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.

(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.
Page 719 of 903

(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.

* * * * *

180. 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:

(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.

* * * * *

181. 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]

182. 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 
Page 720 of 903

refer to exhaust piping as an exhaust stack; this is equivalent to a tailpipe for vehicle 

configurations.

* * * * *

183. 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 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 
Page 721 of 903

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. 

(2) Pressure control. Maintain static pressure at the location where raw exhaust is 

introduced into the tunnel within ±1.2 kPa of atmospheric pressure. You may use a 

booster blower to control this pressure. If you test using more careful pressure control 

and you show by engineering analysis or by test data that you require this level of control 

to demonstrate compliance at the applicable standards, we will maintain the same level of 

static pressure control when we test.

(3) Mixing. Introduce raw exhaust into the tunnel by directing it downstream along the 

centerline of the tunnel. If you dilute directly from the exhaust stack, the end of the 

exhaust stack is considered to be the start of the dilution tunnel. You may introduce a 

fraction of dilution air radially from the tunnel’s inner surface to minimize exhaust 

interaction with the tunnel walls. You may configure the system with turbulence 

generators such as orifice plates or fins to achieve good mixing. We recommend a 

minimum Reynolds number, Re#, of 4000 for the diluted exhaust stream, where Re# is 

based on the inside diameter of the dilution tunnel. Re# is defined in §1065.640.

(4) Flow measurement preconditioning. You may condition the diluted exhaust before 

measuring its flow rate, as long as this conditioning takes place downstream of any

heated HC or PM sample probes, as follows:

(i) You may use flow straighteners, pulsation dampeners, or both of these.

(ii) You may use a filter.

(iii) You may use a heat exchanger to control the temperature upstream of any flow 

meter, but you must take steps to prevent aqueous condensation as described in paragraph 

(c)(6) of this section.

(5) Flow measurement. Section 1065.240 describes measurement instruments for diluted 

exhaust flow.

(6) Aqueous condensation. This paragraph (c)(6) describes how you must address 

aqueous condensation in the CVS. As described below, you may meet these 

requirements by preventing or limiting aqueous condensation in the CVS from the 

exhaust inlet to the last emission sample probe. See that paragraph for provisions related 

to the CVS between the last emission sample probe and the CVS flow meter. You may

heat and/or insulate the dilution tunnel walls, as well as the bulk stream tubing 

downstream of the tunnel to prevent or limit aqueous condensation. Where we allow 

aqueous condensation to occur, use good engineering judgment to ensure that the 

condensation does not affect your ability to demonstrate that your engines comply with 

the applicable standards (see §1065.10(a)).

(i) Preventing aqueous condensation. To prevent condensation, you must keep the 

temperature of internal surfaces, excluding any sample probes, above the dew point of the 

dilute exhaust passing through the CVS tunnel. Use good engineering judgment to 

monitor temperatures in the CVS. For the purposes of this paragraph (c)(6), assume that 

aqueous condensation is pure water condensate only, even though the definition of 

“aqueous condensation” in §1065.1001 includes condensation of any constituents that 

contain water. No specific verification check is required under this paragraph (c)(6)(i), 
Page 722 of 903

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.

(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 
Page 723 of 903

described in paragraphs (d)(2) and (3) of this section. An example of a constant dilution 

ratio PFD is a “secondary dilution PM” measurement system.

(1) Applicability. (i) You may use PFD to extract a proportional raw exhaust sample for 

any batch or continuous PM emission sampling over any transient duty cycle, any steadystate duty cycle, or any ramped-modal cycle.

(ii) You may use PFD to extract a proportional raw exhaust sample for any batch or 

continuous gaseous emission sampling over any transient duty cycle, any steady-state 

duty cycle, or any ramped-modal cycle.

(iii) You may use PFD to extract a proportional raw exhaust sample for any batch or 

continuous field-testing.

(iv)You may use PFD to extract a proportional diluted exhaust sample from a CVS for

any batch or continuous emission sampling.

(v) You may use PFD to extract a constant raw or diluted exhaust sample for any

continuous emission sampling.

(vi) You may use PFD to extract a constant raw or diluted exhaust sample for any steadystate emission sampling.

(2) Constant dilution-ratio PFD. Do one of the following for constant dilution-ratio PFD:

(i) Dilute an already proportional flow. For example, you may do this as a way of 

performing secondary dilution from a CVS tunnel to achieve overall dilution ratio for PM 

sampling.

(ii) Continuously measure constituent concentrations. For example, you might dilute to 

precondition a sample of raw exhaust to control its temperature, humidity, or constituent 

concentrations upstream of continuous analyzers. In this case, you must take into 

account the dilution ratio before multiplying the continuous concentration by the sampled 

exhaust flow rate. 

(iii) Extract a proportional sample from a separate constant dilution ratio PFD system. 

For example, you might use a variable-flow pump to proportionally fill a gaseous storage 

medium such as a bag from a PFD system. In this case, the proportional sampling must 

meet the same specifications as varying dilution ratio PFD in paragraph (d)(3) of this 

section.

(iv) For each mode of a discrete-mode test (such as a locomotive notch setting or a 

specific setting for speed and torque), use a constant dilution ratio for any PM sampling. 

You must change the overall PM sampling system dilution ratio between modes so that 

the dilution ratio on the mode with the highest exhaust flow rate meets §1065.140(e)(2) 

and the dilution ratios on all other modes is higher than this (minimum) dilution ratio by

the ratio of the maximum exhaust flow rate to the exhaust flow rate of the corresponding 

other mode. This is the same dilution ratio requirement for RMC or field transient 

testing. You must account for this change in dilution ratio in your emission calculations.

(3) Varying dilution-ratio PFD. All the following provisions apply for varying dilutionratio PFD:

(i) Use a control system with sensors and actuators that can maintain proportional 

sampling over intervals as short as 200 ms (i.e., 5 Hz control).

(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.
Page 724 of 903

(iv) You may use preprogrammed data if they have been determined for the specific test 

site, duty cycle, and test engine from which you dilute emissions.

(v) We recommend that you run practice cycles to meet the verification criteria in 

§1065.545. Note that you must verify every emission test by meeting the verification 

criteria with the data from that specific test. Data from previously verified practice cycles 

or other tests may not be used to verify a different emission test.

(vi) You may not use a PFD system that requires preparatory tuning or calibration with a

CVS or with the emission results from a CVS. Rather, you must be able to independently 

calibrate the PFD.

(e) Dilution air temperature, dilution ratio, residence time, and temperature control of PM 

samples. Dilute PM samples at least once upstream of transfer lines. You may dilute PM 

samples upstream of a transfer line using full-flow dilution, or partial-flow dilution 

immediately downstream of a PM probe. In the case of partial-flow dilution, you may

have up to 26 cm of insulated length between the end of the probe and the dilution stage, 

but we recommend that the length be as short as practical. The intent of these 

specifications is to minimize heat transfer to or from the emission sample before the final 

stage of dilution, other than the heat you may need to add to prevent aqueous 

condensation. This is accomplished by initially cooling the sample through dilution. 

Configure dilution systems as follows:

(1) Set the dilution air temperature to (25 ±5) °C. Use good engineering judgment to 

select a location to measure this temperature that is as close as practical upstream of the 

point where dilution air mixes with raw exhaust. 

(2) For any PM dilution system (i.e., CVS or PFD), add dilution air to the raw exhaust 

such that the minimum overall ratio of diluted exhaust to raw exhaust is within the range 

of (5:1 to 7:1) and is at least 2:1 for any primary dilution stage. Base this minimum value 

on the maximum engine exhaust flow rate for a given test interval. Either measure the 

maximum exhaust flow during a practice run of the test interval or estimate it based on 

good engineering judgment (for example, you might rely on manufacturer-published 

literature).

(3) Configure any PM dilution system to have an overall residence time of (1.0 to 5.5) s, 

as measured from the location of initial dilution air introduction to the location where PM 

is collected on the sample media. Also configure the system to have a residence time of 

at least 0.50 s, as measured from the location of final dilution air introduction to the 

location where PM is collected on the sample media. When determining residence times 

within sampling system volumes, use an assumed flow temperature of 25 °C and pressure 

of 101.325 kPa.

(4) Control sample temperature to a (47 ±5) °C tolerance, as measured anywhere within 

20 cm upstream or downstream of the PM storage media (such as a filter). Measure this 

temperature with a bare-wire junction thermocouple with wires that are (0.500 ±0.025) 

mm diameter, or with another suitable instrument that has equivalent performance.

184. 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.
Page 725 of 903

(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:

(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 fourstroke spark-ignition engines at or below 19 kW, we recommend heating the probe to 

minimize hydrocarbon contamination consistent with good engineering judgment. If you 

routinely fail the contamination check in the 1065.520 pretest check, we recommend 

heating the probe section to approximately 190 °C to minimize contamination.

(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 preclassifier 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 crossfittings 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 
Page 726 of 903

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 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 
Page 727 of 903

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 fourstroke spark-ignition engines at or below 19 kW. If you use a thermal chiller upstream of 

an NO2-to-NO converter or in a sampling system without an NO2-to-NO converter, the 

chiller must meet the NO2 loss-performance check specified in §1065.376. Monitor the 

dewpoint, Tdew, and absolute pressure, ptotal, downstream of a thermal chiller. You may

use continuously recorded values of Tdew and ptotal in the amount of water calculations 

specified in §1065.645. If it is valid to assume the degree of saturation in the thermal 

chiller, you may calculate Tdew based on the known chiller performance and continuous 

monitoring of chiller temperature, Tchiller. If it is valid to assume a constant temperature 

offset between Tchiller and Tdew, due to a known and fixed amount of sample reheat 

between the chiller outlet and the temperature measurement location, you may factor in 

this assumed temperature offset value into emission calculations. If we ask for it, you 

must show by engineering analysis or by data the validity of any assumptions allowed by

this paragraph (e)(2)(ii). For our testing we may use average temperature and pressure

values over the test interval or a nominal pressure value that we estimate as the dryer’s 

average pressure expected during testing as constant values in the calculations specified 

in §1065.645. For your testing you may use the maximum temperature and minimum 

pressure values observed during a test interval or duty cycle or the high alarm 

temperature setpoint and the low alarm pressure setpoint as constant values in the amount 

of water calculations specified in §1065.645. For your testing you may also use a 

nominal ptotal, which you may estimate as the dryer’s lowest absolute pressure expected 

during testing.

(3) 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.
Page 728 of 903

* * * * *

185. 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 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 fourstroke 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.

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 
Page 729 of 903

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]

186. Section 1065.201 is amended by revising paragraphs (b), (d), (e), and (h) to read 

as follows:

§1065.201 Overview and general provisions.

* * * * *

(b) Instrument types. You may use any of the specified instruments as described in this 

subpart to perform emission tests. If you want to use one of these instruments in a way 

that is not specified in this subpart, or if you want to use a different instrument, you must 

first get us to approve your alternate procedure under §1065.10. Where we specify more 

than one instrument for a particular measurement, we may identify which instrument 

serves as the reference for comparing with an alternate procedure. You may generally 

use instruments with compensation algorithms that are functions of other gaseous 

measurements and the 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.

187. Section 1065.202 is revised to read as follows:

§1065.202 Data updating, recording, and control.
Page 730 of 903

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 data acquisition and control systems that can record at the specified minimum 

frequencies, as follows:

Table 1 of §1065.202–Data recording and control minimum frequencies

Applicable 

Test Protocol 

Section

Measured Values

Minimum 

Command and 

Control 

Frequency

Minimum 

Recording 

Frequency

§1065.510 Speed and torque during an engine step-map 1 Hz 1 mean value 

per step

§1065.510 Speed and torque during an engine sweep-map 5 Hz 1 Hz means

§1065.514

§1065.530

Transient duty cycle reference and feedback speeds 

and torques 5 Hz 1 Hz means

§1065.514

§1065.530

Steady-state and ramped-modal duty cycle reference 

and feedback speeds and torques 1 Hz 1 Hz

§1065.520

§1065.530

§1065.550

Continuous concentrations of raw or dilute analyzers N/A 1 Hz

§1065.520

§1065.530

§1065.550

Batch concentrations of raw or dilute analyzers N/A 1 mean value 

per test interval

§1065.530

§1065.545

Diluted exhaust flow rate from a CVS with a heat 

exchanger upstream of the flow measurement N/A 1 Hz

§1065.530

§1065.545

Diluted exhaust flow rate from a CVS without a heat 

exchanger upstream of the flow measurement N/A 1 Hz means

§1065.530

§1065.545 Intake-air or raw-exhaust flow rate N/A 1 Hz means

§1065.530

§1065.545 Dilution air if actively controlled 5 Hz 1 Hz means

§1065.530

§1065.545 Sample flow from a CVS that has a heat exchanger 1 Hz 1 Hz

§1065.530

§1065.545

Sample flow from a CVS does not have a heat 

exchanger 5 Hz 1 Hz means

188. Section 1065.205 is amended by revising the introductory text to read as follows:

§1065.205 Performance specifications for measurement instruments.

Your test system as a whole must meet all the calibrations, verifications, and testvalidation criteria specified outside 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.

* * * * *

189. 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:
Page 731 of 903

(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.

* * * * *

190. Section 1065.230 is amended by revising paragraph (d) to read as follows:

§1065.230 Raw exhaust flow meter.

* * * * *

(d) Exhaust cooling. You may cool raw exhaust upstream of a raw-exhaust flow meter, 

as long as you observe all the following provisions: 

(1) Do not sample PM downstream of the cooling.

(2) If cooling causes exhaust temperatures above 202 °C to decrease to below 180 °C, do 

not sample NMHC downstream of the cooling for compression-ignition engines, twostroke spark-ignition engines, or four-stroke spark-ignition engines at or below 19 kW.

(3) The cooling must not cause aqueous condensation.

191. Section 1065.240 is amended by revising paragraph (d) to read as follows:

§1065.240 Dilution air and diluted exhaust flow meters.

* * * * *

(d) Exhaust cooling. You may cool diluted exhaust upstream of a dilute-exhaust flow 

meter, as long as you observe all the following provisions: 

(1) Do not sample PM downstream of the cooling.

(2) If cooling causes exhaust temperatures above 202 °C to decrease to below 180 °C, do 

not sample NMHC downstream of the cooling for compression-ignition engines, twostroke spark-ignition engines, or four-stroke spark-ignition engines at or below 19 kW.

(3) The cooling must not cause aqueous condensationas described in §1065.140(c)(6).

192. 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 732 of 903

HYDROCARBON MEASUREMENTS

193. 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).

194. 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.

195. A new §1065.269 is added to subpart C to read as follows:

§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
Page 733 of 903

196. 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.

* * * * *

197. 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.

* * * * *

198. 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 highresolution narrow band mid-infrared analyzers.

(4) Photoacoustic analyzer. Use an optical wheel configuration that gives analytical 

priority to measurement of the least stable components in the sample. Select a sample 

integration time of at least 5 seconds. Take into account sample chamber and sample line 

volumes when determining flush times for your instrument.

(5) Gas chromatograph analyzer. You may use a gas chromatograph with an electroncapture detector (GC-ECD) to measure N2O concentrations of diluted exhaust for batch 

sampling.

(i)You may use a packed or porous layer open tubular (PLOT) column phase of suitable 

polarity and length to achieve adequate resolution of the N2O peak for analysis. 

Examples of acceptable columns are a PLOT column consisting of bonded polystyrenedivinylbenzene or a Porapack Q packed column. Take the column temperature profile 

and carrier gas selection into consideration when setting up your method to achieve 

adequate N2O peak resolution.
Page 734 of 903

(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

199. 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

200. 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

201. 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]

202. 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.
Page 735 of 903

Repeatability: Not required, but recommended for initial 

installation.

Noise: Not required, but recommended for initial installation.

§1065.307: Linearity verification

Speed: Upon initial installation, within 370 days before testing 

and after major maintenance.

Torque: Upon initial installation, within 370 days before testing 

and after major maintenance.

Electrical power, current, and voltage: Upon initial installation, 

within 370 days before testing and after major maintenance.2

Fuel flow rate: Upon initial installation, within 370 days before 

testing, and after major maintenance.

Intake-air, dilution air, diluted exhaust, and batch sampler flow 

rates: Upon initial installation, within 370 days before testing and 

after major maintenance, unless flow is verified by propane check 

or by carbon or oxygen balance.

Raw exhaust flow rate: Upon initial installation, within 185 days 

before testing and after major maintenance, unless flow is verified 

by propane check or by carbon or oxygen balance.

Gas dividers: Upon initial installation, within 370 days before 

testing, and after major maintenance.

Gas analyzers (unless otherwise noted): Upon initial installation, 

within 35 days before testing and after major maintenance.

FTIR and photoacoustic analyzers: Upon initial installation, 

within 370 days before testing and after major maintenance.

GC-ECD: Upon initial installation and after major maintenance.

PM balance: Upon initial installation, within 370 days before 

testing and after major maintenance.

Pressure, temperature, and dewpoint: Upon initial installation, 

within 370 days before testing and after major maintenance.

§1065.308: Continuous gas analyzer system 

response and updating-recording verification—

for gas analyzers not continuously compensated 

for other gas species

Upon initial installation or after system modification that would 

affect response.

§1065.309: Continuous gas analyzer systemresponse and updating-recording verification—

for gas analyzers continuously compensated for 

other gas species

Upon initial installation or after system modification that would 

affect response.

§1065.310: Torque Upon initial installation and after major maintenance.

§1065.315: Pressure, temperature, dewpoint Upon initial installation and after major maintenance.

§1065.320: Fuel flow Upon initial installation and after major maintenance.

§1065.325: Intake flow Upon initial installation and after major maintenance.

§1065.330: Exhaust flow Upon initial installation and after major maintenance.

§1065.340: Diluted exhaust flow (CVS) Upon initial installation and after major maintenance.

§1065.341: CVS and batch sampler verification3 Upon initial installation, within 35 days before testing, and after 

major maintenance.

§1065.342 Sample dryer verification

For thermal chillers: upon installation and after major 

maintenance.

For osmotic membranes; upon installation, within 35 days of 

testing, and after major maintenance.

§1065.345: Vacuum leak

For laboratory testing: upon initial installation of the sampling 

system, within 8 hours before the start of the first test interval of 

each duty-cycle sequence, and after maintenance such as pre-filter 

changes.

For field testing: after each installation of the sampling system on 

the vehicle, prior to the start of the field test, and after 

maintenance such as pre-filter changes.

§1065.350: CO2 NDIR H2O interference Upon initial installation and after major maintenance.

§1065.355: CO NDIR CO2 and H2O interference Upon initial installation and after major maintenance.

§1065.360: FID calibration

THC FID optimization, and THC FID 

verification

Calibrate all FID analyzers: upon initial installation and after 

major maintenance.

Optimize and determine CH4response for THC FID analyzers:
Page 736 of 903

upon initial installation and after major maintenance.

Verify CH4response for THC FID analyzers: upon initial 

installation, within 185 days before testing, and after major 

maintenance.

§1065.362: Raw exhaust FID O2interference

For all FID analyzers: upon initial installation, and after major 

maintenance.

For THC FID analyzers: upon initial installation, after major 

maintenance, and after FID optimization according to §1065.360.

§1065.365: Nonmethane cutter penetration Upon initial installation, within 185 days before testing, and after 

major maintenance.

§1065.369: H2O, CO, and CO2interference 

verification for ethanol photoacoustic analyzers Upon initial installation and after major maintenance.

§1065.370: CLD CO2 and H2O quench Upon initial installation and after major maintenance.

§1065.372: NDUV HC and H2O interference Upon initial installation and after major maintenance.

§1065.375: N2O analyzer interference Upon initial installation and after major maintenance.

§1065.376: Chiller NO2 penetration Upon initial installation and after major maintenance.

§1065.378: NO2-to-NO converter conversion Upon initial installation, within 35 days before testing, and after 

major maintenance.

§1065.390: PM balance and weighing

Independent verification: upon initial installation, within 370 days 

before testing, and after major maintenance.

Zero, span, and reference sample verifications: within 12 hours of 

weighing, and after major maintenance.

§1065.395: Inertial PM balance and weighing

Independent verification: upon initial installation, within 370 days 

before testing, and after major maintenance.

Other verifications: upon initial installation and after major 

maintenance.

1

Perform calibrations and verifications more frequently than we specify, according to measurement system 

manufacturer instructions and good engineering judgment.

2

Perform linearity verification either for electrical power or for current and voltage.

3The CVS verification described in §1065.341 is not required for systems that agree within ±2 % based on a chemical 

balance of carbon or oxygen of the intake air, fuel, and diluted exhaust.

203. 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.

* * * * *

204. 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 737 of 903

(b) Performance requirements. If a measurement system does not meet the applicable 

linearity criteria referenced in Table 1 of this section, correct the deficiency by recalibrating, servicing, or replacing components as needed. Repeat the linearity

verification after correcting the deficiency to ensure that the measurement system meets 

the linearity criteria. Before you may use a measurement system that does not meet 

linearity criteria, you must demonstrate to us that the deficiency does not adversely affect 

your ability to demonstrate compliance with the applicable standards.

(c) Procedure. Use the following linearity verification protocol, or use good engineering 

judgment to develop a different protocol that satisfies the intent of this section, as 

described in paragraph (a) of this section:

(1) In this paragraph (c), the letter “y” denotes a generic measured quantity, the 

superscript over-bar denotes an arithmetic mean (such as y ), and the subscript “ref” 

denotes the known or reference quantity being measured.

(2) Use good engineering judgment to operate a measurement system at normal operating 

conditions. This may include any specified adjustment or periodic calibration of the 

measurement system.

(3) If applicable, zero the instrument as you would before an emission test by introducing 

a zero signal. Depending on the instrument, this may be a zero-concentration gas, a 

reference signal, a set of reference thermodynamic conditions, or some combination of 

these. For gas analyzers, use a zero gas that meets the specifications of §1065.750 and 

introduce it directly at the analyzer port.

(4) If applicable, span the instrument as you would before an emission test by introducing 

a span signal. Depending on the instrument, this may be a span-concentration gas, a 

reference signal, a set of reference thermodynamic conditions, or some combination of 

these. For gas analyzers, use a span gas that meets the specifications of §1065.750 and 

introduce it directly at the analyzer port.

(5) If applicable, after spanning the instrument, check zero with the same signal you used 

in paragraph (c)(3) of this section. Based on the zero reading, use good engineering 

judgment to determine whether or not to rezero and or re-span the instrument before 

continuing.

(6) For all measured quantities, use the instrument manufacturer’s recommendations and 

good engineering judgment to select reference values, yrefi, that cover a range of values 

that you expect would prevent extrapolation beyond these values during emission testing. 

We recommend selecting a zero reference signal as one of the reference values for the 

linearity verification. For pressure, temperature, dewpoint, power, current, voltage, 

photoacoustic analyzers, and GC-ECD linearity verifications, we recommend at least 

three reference values. For all other linearity verifications select at least ten reference 

values.

(7) Use the instrument manufacturer’s recommendations and good engineering judgment 

to select the order in which you will introduce the series of reference values. For 

example, you may select the reference values randomly to avoid correlation with 

previous measurements and to avoid hysteresis; you may select reference values in 

ascending or descending order to avoid long settling times of reference signals; or you 

may select values to ascend and then descend to incorporate the effects of any instrument 

hysteresis into the linearity verification.
Page 738 of 903

(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 NIST-traceable within 0.5 % uncertainty, if not 

specified elsewhere in this part 1065. Use the following recommended methods to 

generate reference values or use good engineering judgment to select a different 

reference:

(1) Speed. Run the engine or dynamometer at a series of steady-state speeds and use a 

strobe, photo tachometer, or laser tachometer to record reference speeds.

(2) Torque. Use a series of calibration weights and a calibration lever arm to simulate 

engine torque. You may instead use the engine or dynamometer itself to generate a 

nominal torque that is measured by a reference load cell or proving ring in series with the 

torque-measurement system. In this case, use the reference load cell measurement as the 

reference value. Refer to §1065.310 for a torque-calibration procedure similar to the 

linearity verification in this section.

(3) Electrical power, current, and voltage. You must perform linearity verification for 

either electrical power, 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 
Page 739 of 903

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, sample and record 

values of xrefi for 30 seconds and use the arithmetic mean of the values, ref x , as the 

reference value. Refer to §1065.602 for an example of calculating arithmetic mean.

(ii) Using good engineering judgment and the gas divider manufacturer’s 

recommendations, use one or more reference flow meters to measure the flow rates of the 

gas divider and verify the gas-division value.

(7) Continuous constituent concentration. For reference values, use a series of gas 

cylinders of known gas concentration or use a gas-division system that is known to be 

linear with a span gas. Gas cylinders, gas-division systems, and span gases that you use 

for reference values must meet the specifications of §1065.750.

(8) Temperature. You may perform the linearity verification for temperature 

measurement systems with thermocouples, RTDs, and thermistors by removing the 

sensor from the system and using a simulator in its place. Use a NIST-traceable 

simulator that is independently calibrated and, as appropriate, cold-junctioncompensated. The simulator uncertainty scaled to absolute temperature must be less than 
Page 740 of 903

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:

(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.
Page 741 of 903

(D) PM sample.

(E) Chiller sample, for gaseous sampling systems that use thermal chillers to dry samples

and use chiller temperature to calculate the dewpoint at the outlet of the chiller. For your 

testing, if you choose to use a high alarm temperature setpoint for the chiller temperature 

as a constant value in determining the amount of water removed from the emission 

sample, you may use good engineering judgment to verify the accuracy of the high alarm 

temperature setpoint instead of linearity verification on the chiller temperature. To verify

that the alarm trip point value is no less than 2.0 °C below the reference value at the trip 

point, we recommend that you input a reference simulated temperature signal below the 

alarm trip point and increase this signal until the high alarm trips.

(ii) Linearity verification is required for the following temperature measurements if these 

temperature measurements are specified by the engine manufacturer:

(A) Fuel inlet.

(B) Air outlet to the test cell’s charge air cooler air outlet, for engines tested with a 

laboratory heat exchanger that simulates an installed charge air cooler.

(C) Coolant inlet to the test cell’s charge air cooler, for engines tested with a laboratory

heat exchanger that simulates an installed charge air cooler.

(D) Oil in the sump/pan.

(E) Coolant before the thermostat, for liquid-cooled engines.

(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 742 of 903

Table 1 of §1065.307–Measurement systems that require linearity verification.

Measurement 

system Quantity Linearity criteria

| xmin(a1-1)+a0 | a1 SEE r

2

Speed fn

≤ 0.05 % ∙ 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 exhaust

flow rate1 n ≤ 1 % ∙ max n 0.98-1.02 ≤ 2 % ∙ max n ≥ 0.990

Batch sampler

flow rates1 n ≤ 1 % ∙ max n 0.98-1.02 ≤ 2 % ∙ max n ≥ 0.990

Gas dividers x/xspan

≤ 0.5 % ∙ 

xmax/xspan

0.98-1.02 ≤ 2 % ∙ 

xmax/xspan

≥ 0.990

Gas analyzers for 

laboratory testing x ≤ 0.5 % ∙ max x 0.99-1.01 ≤ 1 % ∙ max x ≥ 0.998

Gas analyzers for 

field testing x ≤ 1 % ∙ max x 0.99-1.01 ≤ 1 % ∙ max x ≥ 0.998

PM balance m ≤ 1 % ∙ mmax 0.99-1.01 ≤ 1 % ∙ mmax ≥ 0.998

Pressures p ≤ 1 % ∙ max p 0.99-1.01 ≤ 1 % ∙ max p ≥ 0.998

Dewpoint for 

intake air, PMstabilization and 

balance 

environments

Tdew

≤ 0.5 % ∙ 

Tdewmax

0.99-1.01

≤ 0.5 % 

∙ Tdewmax

≥ 0.998

Other dewpoint 

measurements Tdew ≤ 1 % ∙ Tdewmax 0.99-1.01 ≤ 1 % ∙ Tdewmax ≥ 0.998

Analog-to-digital 

conversion of 

temperature signals

T ≤ 1 % ∙ Tmax 0.99-1.01 ≤ 1 % ∙ Tmax ≥ 0.998

1

For flow meters that determine volumetric flow rate, Vstd , you may substitute Vstd  for n as the quantity and 

substitute Vstdmax  for max n .

205. 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 
Page 743 of 903

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 multi-gas span gases. You may use a gas blending or mixing 

device to blend span gases. A gas blending or mixing device is recommended when 

blending span gases diluted in N2 with span gases diluted in air. You may use a multi-gas 

span gas, such as NO-CO-CO2-C3H8-CH4, to verify multiple analyzers at the same time. 

If you use standard binary span gases, you must run separate response tests for each 

analyzer. In designing your experimental setup, avoid pressure pulsations due to 

stopping the flow through the gas-blending device. The change in gas concentration must 

be at least 20 % of the analyzer's range.

(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.

(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:
Page 744 of 903

(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.

206. 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
Page 745 of 903

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 NO2 span gas by passing it through a sealed 

humidification vessel that contains water. You must humidify NO2 span gas with another 

moist gas stream. We recommend humidifying your NO-CO-CO2-C3H8-CH4, balance N2

blended gas by flowing the gas mixture through a sealed vessel that humidifies the gas by 

bubbling it through distilled water and then mixing the gas with dry NO2 gas, balance 

purified air. If your system does not use a sample dryer to remove water from the sample 

gas, you must humidify your span gas to the highest sample H2O content that you 

estimate during emission sampling. If your system uses a sample dryer during testing, it 

must pass the sample dryer verification check in §1065.342, and you must humidify your 

span gas to an H2O content greater than or equal to the level determined in 

§1065.145(e)(2). If you are humidifying span gases without NO2, use good engineering 

judgment to ensure that the wall temperatures in the transfer lines, fittings, and valves 

from the humidifying system to the probe are above the dewpoint required for the target

H2O content. If you are humidifying span gases with NO2, use good engineering 

judgment to ensure that there is no condensation in the transfer lines, fittings, or valves 

from the point where humidified gas is mixed with NO2 span gas to the probe. We 

recommend that you design your setup so that the wall temperatures in the transfer lines, 

fittings, and valves from the humidifying system to the probe are at least 5 oC above the 

local sample gas dewpoint. Operate the measurement and sample handling system as you 

do for emission testing. Make no modifications to the sample handling system to reduce 

the risk of condensation. Flow humidified gas through the sampling system before this 

check to allow stabilization of the measurement system’s sampling handling system to 

occur, as it would for an emission test.

* * * * *

(g) Optional procedure. Follow the optional procedures in §1065.308(g), noting that you 

may use compensating gases mixed with ambient air for oxygen analyzers.

(h) Analyzers with H2O compensation sampling downstream of a sample dryer. You 

may omit humidifying the span gas as described in this paragraph (h). If an analyzer 

compensates only for H2O, you may apply the requirements of §1065.308 instead of the 
Page 746 of 903

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

207. Section 1065.310 is amended by revising paragraph (d) to read as follows:

§1065.310 Torque calibration.

* * * * *

(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 torquemeasuring range, spacing the force quantities about equally over the range. Oscillate or 

rotate the dynamometer during calibration to reduce frictional static hysteresis. In this 

case, the reference torque is determined by multiplying the force output from the 

reference meter (such as a strain gage, load transducer, or proving ring) by its effective 

lever-arm length, which you measure from the point where the force measurement is 

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.

208. 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.

* * * * *

209. 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 
Page 747 of 903

term CVS to mean PFD or batch sampler as appropriate. A propane check also serves as 

a batch-sampler verification to determine if there is a discrepancy in a batch sampling 

system that extracts a sample from a CVS, as described in paragraph (g) of this section. 

Using good engineering judgment and safe practices, this check may be performed using 

a gas other than propane, such as CO2 or CO. A failed propane check might indicate one 

or more problems that may require corrective action, as follows:

* * * * *

(d) If you performed the vacuum-side leak verification of the HC sampling system as 

described in paragraph (c)(8) of this section, you may use the HC contamination 

procedure in §1065.520(f) to verify HC contamination. Otherwise, zero, span, and verify

contamination of the HC sampling system, as follows:

* * * * *

(f) * * *

(3) Calculate total C3H8 mass based on your CVS and HC data as described in §1065.650 

(40 CFR 1066.610 for vehicle testing) and §1065.660, using the molar mass of C3H8, 

MC3H8, instead the effective molar mass of HC, MHC.

* * * * *

210. 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 

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, 
Page 748 of 903

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.

211. 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 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 
Page 749 of 903

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 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

212. 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
Page 750 of 903

downstream of a nonmethane cutter, you may calibrate that FID using CH4 calibration 

gases with the cutter. Regardless of the calibration gas composition, calibrate on a 

carbon number basis of one (C1). For example, if you use a C3H8 span gas of 

concentration 200 mol/mol, span the FID to respond with a value of 600 mol/mol. As 

another example, if you use a CH4 span gas with a concentration of 200 mol/mol, span 

the FID to respond with a value of 200 mol/mol.

* * * * *

(d) THC FID CH4 response factor determination. This procedure is only for FID 

analyzers that measure THC. Since FID analyzers generally have a different response to 

CH4 versus C3H8, determine each THC-FID analyzer’s CH4 response factor, RFCH4[THCFID], after FID optimization. Use the most recent RFCH4[THC-FID] measured according to 

this section in the calculations for HC determination described in §1065.660 to 

compensate for CH4 response. Determine RFCH4[THC-FID] as follows, noting that you do 

not determine RFCH4[THC-FID] for FIDs that are calibrated and spanned using CH4 with a 

nonmethane cutter:

(1) Select a C3H8 span gas concentration that you use to span your analyzers before 

emission testing. Use only span gases that meet the specifications of §1065.750. Record 

the C3H8 concentration of the gas.

(2) Select a CH4 span gas concentration that you use to span your analyzers before 

emission testing. Use only span gases that meet the specifications of §1065.750. Record 

the CH4 concentration of the gas.

(3) Start and operate the FID analyzer according to the manufacturer’s instructions.

(4) Confirm that the FID analyzer has been calibrated using C3H8. Calibrate on a carbon 

number basis of one (C1). For example, if you use a C3H8 span gas of concentration 200 

mol/mol, span the FID to respond with a value of 600 mol/mol.

(5) Zero the FID with a zero gas that you use for emission testing.

(6) Span the FID with the C3H8 span gas that you selected under paragraph (d)(1) of this 

section.

(7) Introduce at the sample port of the FID analyzer, the CH4 span gas that you selected 

under paragraph (d)(2) of this section.

(8) Allow time for the analyzer response to stabilize. Stabilization time may include time 

to purge the analyzer and to account for its response.

(9) While the analyzer measures the CH4 concentration, record 30 seconds of sampled 

data. Calculate the arithmetic mean of these values. 

(10) For analyzers with multiple ranges, you need to perform the procedure in this 

paragraph (d) only on a single range. 

(11) Divide the mean measured concentration by the recorded span concentration of the 

CH4 calibration gas. The result is the FID analyzer’s response factor for CH4, RFCH4[THCFID].

(e) THC FID CH4 response verification. This procedure is only for FID analyzers that 

measure THC. 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:
Page 751 of 903

* * * * *

(4) For analyzers with multiple ranges, you need to perform the procedure in this 

paragraph (e) only on a single range.

* * * * *

213. Section 1065.362 is amended by adding paragraph (d)(15) to read as follows:

§1065.362 Non-stoichiometric raw exhaust FID O2 interference verification.

* * * * *

(d) * * *

(15) For analyzers with multiple ranges, you need to perform the procedure in this 

paragraph (d) only on a single range. 

214. 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.

* * * * *

(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 
Page 752 of 903

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.

* * * * *

215. 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.

(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

216. 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 
Page 753 of 903

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.

* * * * *

217. Section 1065.375 is amended by revising paragraph (d) to read as follows:

§1065.375 Interference verification for N2O analyzers.

* * * * *

(d) Procedure. Perform the interference verification as follows:

(1) Start, operate, zero, and span the N2O analyzer as you would before an emission test. 

If the sample is passed through a dryer during emission testing, you may run this 

verification test with the dryer if it meets the requirements of §1065.342. Operate the 

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 
Page 754 of 903

the vessel pressure and temperature. Use good engineering judgment to estimate the H2O

content. For example, you may use previous direct measurements of H2O content to 

verify the vessel’s level of saturation.

(5) If a sample dryer is not used in this verification test, use good engineering judgment

to prevent condensation in the transfer lines, fittings, or valves from the point where xH2O

is measured to the analyzer. We recommend that you design your system so that the wall 

temperatures in the transfer lines, fittings, and valves from the point where xH2O is 

measured to the analyzer are at least 5 oC above the local sample gas dewpoint.

(6) Allow time for the analyzer response to stabilize. Stabilization time may include time 

to purge the transfer line and to account for analyzer response.

(7) While the analyzer measures the sample’s concentration, record its output for 30 

seconds. Calculate the arithmetic mean of this data. When performed with all the gases 

simultaneously, this is the combined interference.

(8) The analyzer meets the interference verification if the result of paragraph (d)(7) of 

this section meets the tolerance in paragraph (c) of this section.

(9) You may also run interference procedures separately for individual interference gases. 

If the interference gas levels used are higher than the maximum levels expected during 

testing, you may scale down each observed interference value (the arithmetic mean of 30 

second data described in paragraph (d)(7) of this section) by multiplying the observed 

interference by the ratio of the maximum expected concentration value to the actual value 

used during this procedure. You may run separate interference concentrations of H2O 

(down to 0.025 mol/mol H2O content) that are lower than the maximum levels expected 

during testing, but you must scale up the observed H2O interference by multiplying the 

observed interference by the ratio of the maximum expected H2O concentration value to 

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.

218. 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.
Page 755 of 903

(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.

(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]

219. 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 in-use configuration, consistent with good 

engineering judgment. For example, §§1065.122 and 1065.125 allow the use of test cell 

components to represent engine cooling and intake air systems.

* * * * *

(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 enginerelated component 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.
Page 756 of 903

(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]

220. 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:

* * * * *

221. 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 
Page 757 of 903

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.

(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.

222. 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 steadystate testing following transient testing, we may consider the previous test cycle as 
Page 758 of 903

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).

(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.

223. 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 
Page 759 of 903

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:

(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.

(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.

224. Section 1065.526 is amended by revising paragraphs (c)(3) and (d)(1) to read as 

follows:
Page 760 of 903

§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.

* * * * *

225. 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. 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 hotstart 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 hotstabilized 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 
Page 761 of 903

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 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.

* * * * *

226. Section 1065.545 is revised to read as follows:
Page 762 of 903

§1065.545 Verification of proportional flow control for batch sampling.

For any proportional batch sample such as a bag or PM filter, demonstrate that 

proportional sampling was maintained using one of the following, noting that you may

omit up to 5 % of the total number of data points as outliers:

(a) For any pair of flow rates, use recorded sample and total flow rates, where total flow 

rate means the raw exhaust flow rate for raw exhaust sampling and the dilute exhaust 

flow rate for CVS sampling, or their 1 Hz means with the statistical calculations in 

§1065.602. Determine the standard error of the estimate, SEE, of the sample flow rate 

versus the total flow rate. For each test interval, demonstrate that SEE was less than or 

equal to 3.5 % of the mean sample flow rate.

(b) For any pair of flow rates, use recorded sample and total flow rates, where total flow 

rate means the raw exhaust flow rate for raw exhaust sampling and the dilute exhaust 

flow rate for CVS sampling, or their 1 Hz means to demonstrate that each flow rate was 

constant within ±2.5 % of its respective mean or target flow rate. You may use the 

following options instead of recording the respective flow rate of each type of meter:

(1) Critical-flow venturi option. For critical-flow venturis, you may use recorded venturiinlet conditions or their 1 Hz means. Demonstrate that the flow density at the venturi 

inlet was constant within ±2.5 % of the mean or target density over each test interval. 

For a CVS critical-flow venturi, you may demonstrate this by showing that the absolute 

temperature at the venturi inlet was constant within ±4 % of the mean or target absolute 

temperature over each test interval. 

(2) Positive-displacement pump option. You may use recorded pump-inlet conditions or 

their 1 Hz means. Demonstrate that the flow density at the pump inlet was constant 

within ±2.5 % of the mean or target density over each test interval. For a CVS pump, 

you may demonstrate this by showing that the absolute temperature at the pump inlet was 

constant within ±2 % of the mean or target absolute temperature over each test interval.

(c) Using good engineering judgment, demonstrate with an engineering analysis that the 

proportional-flow control system inherently ensures proportional sampling under all 

circumstances expected during testing. For example, you might use CFVs for both 

sample flow and total dilute exhaust (CVS) flow and demonstrate that they always have 

the same inlet pressures and temperatures and that they always operate under critical-flow 

conditions.

227. 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):

* * * * *

228. Section 1065.550 is revised to read as follows:

§1065.550 Gas analyzer range verification and drift verification.
Page 763 of 903

(a) Range verification. If an analyzer operated above 100 % of its range at any time 

during the test, perform the following steps:

(1) For batch sampling, re-analyze the sample using the lowest analyzer range that results 

in a maximum instrument response below 100 %. Report the result from the lowest range 

from which the analyzer operates below 100 % of its range.

(2) For continuous sampling, repeat the entire test using the next higher analyzer range. 

If the analyzer again operates above 100 % of its range, repeat the test using the next 

higher range. Continue to repeat the test until the analyzer always operates at less than 

100 % of its range.

(b) Drift verification. Gas analyzer drift verification is required for all gaseous exhaust 

constituents for which an emission standard applies. It is also required for CO2 even if 

there is no CO2 emission standard. It is not required for other gaseous exhaust 

constituents for which only a reporting requirement applies (such as CH4 and N2O).

(1) Verify drift using one of the following methods:

(i) For regulated exhaust constituents determined from the mass of a single component, 

perform drift verification based on the regulated constituent. For example, when NOx

mass is determined with a dry sample measured with a CLD and the removed water is 

corrected based on measured CO2, CO, THC, and NOx concentrations, you must verify 

the calculated NOx value.

(ii) For regulated exhaust constituents determined from the masses of multiple 

subcomponents, perform the drift verification based on either the regulated constituent or 

all the mass subcomponents. For example, when NOx is measured with separate NO and 

NO2 analyzers, you must verify either the NOx value or both the NO and NO2 values.

(iii) For regulated exhaust constituents determined from the concentrations of multiple 

gaseous emission subcomponents prior to performing mass calculations, perform drift 

verification on the regulated constituent. You may not verify the concentration 

subcomponents (e.g., THC and CH4 for NMHC) separately. For example, for NMHC 

measurements, perform drift verification on NMHC; do not verify THC and CH4

separately.

(2) Drift verification requires two sets of emission calculations. For each set of 

calculations, include all the constituents in the drift verification. Calculate one set using 

the data before drift correction and calculate the other set after correcting all the data for 

drift according to §1065.672. Note that for purposes of drift verification, you must leave 

unaltered any negative emission results over a given test interval (i.e., do not set them to 

zero). These unaltered results are used when verifying either test interval results or 

composite brake-specific emissions over the entire duty cycle for drift. For each 

constituent to be verified, both sets of calculations must include the following:

(i) Calculated mass (or mass rate) emission values over each test interval.

(ii) If you are verifying each test interval based on brake-specific values, calculate brakespecific emission values over each test interval.

(iii) If you are verifying over the entire duty cycle, calculate composite brake-specific 

emission values.

(3) The duty cycle is verified for drift if you satisfy the following criteria:

(i) For each regulated gaseous exhaust constituent, you must satisfy one of the following:

(A) For each test interval of the duty cycle, the difference between the uncorrected and 

the corrected brake-specific emission values of the regulated constituent must be within 
Page 764 of 903

±4 % of the uncorrected value or the applicable emissions standard, whichever is greater. 

Alternatively, the difference between the uncorrected and the corrected emission mass (or 

mass rate) values of the regulated constituent must be within 4 % of the uncorrected 

value or the composite work (or power) multiplied by the applicable emissions standard, 

whichever is greater. For purposes of verifying each test interval, you may use either the 

reference or actual composite work (or power).

(B) For each test interval of the duty cycle and for each mass subcomponent of the 

regulated constituent, the difference between the uncorrected and the corrected brakespecific emission values must be within ±4 % of the uncorrected value. Alternatively, the 

difference between the uncorrected and the corrected emissions mass (or mass rate) 

values must be within ±4 % of the uncorrected value.

(C) For the entire duty cycle, the difference between the uncorrected and the corrected 

composite brake-specific emission values of the regulated constituent must be within ±4 

% of the uncorrected value or applicable emission standard, whichever is greater.

(D) For the entire duty cycle and for each subcomponent of the regulated constituent, the 

difference between the uncorrected and the corrected composite brake-specific emission 

values must be within ±4 % of the uncorrected value.

(ii) Where no emission standard applies for CO2, you must satisfy one of the following:

(A) For each test interval of the duty cycle, the difference between the uncorrected and 

the corrected brake-specific CO2 values must be within ±4 % of the uncorrected value; or 

the difference between the uncorrected and the corrected CO2 mass (or mass rate) values 

must be within ±4 % of the uncorrected value.

(B) For the entire duty cycle, the difference between the uncorrected and the corrected 

composite brake-specific CO2 values must be within ±4 % of the uncorrected value.

(4) If the test is not verified for drift as described in paragraph (b)(1) of this section, you 

may consider the test results for the duty cycle to be valid only if, using good engineering 

judgment, the observed drift does not affect your ability to demonstrate compliance with 

the applicable emission standards. For example, if the drift-corrected value is less than 

the standard by at least two times the absolute difference between the uncorrected and 

corrected values, you may consider the data to be verified for demonstrating compliance 

with the applicable standard.

Subpart G—[Amended]

229. 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.

* * * * *

230. Section 1065.630 is revised to read as follows:
Page 765 of 903

§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

231. Section 1065.640 is amended by revising paragraphs (a), (b), and (e) to read as 

follows:

§1065.640 Flow meter calibration calculations.

* * * * *

(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:
Page 766 of 903

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

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

 





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
Page 767 of 903

s

1 100.103 98.290

20.085 100.103

K



 

Ks = 0.006700 s/r

(3) Perform a least-squares regression of PDP volume pumped per revolution, Vrev, versus 

PDP slip correction factor, Ks, by calculating slope, a1, and intercept, a0, as described in 

§1065.602.

(4) Repeat the procedure in paragraphs (b)(1) through (3) of this section for every speed 

that you run your PDP.

(5) The following example illustrates these calculations:

Table 1 of §1065.640–

Example of PDP calibration data

nPDP f

(r/min)

a1 

(m3/min)

a0 

(m3/r)

755.0 50.43 0.056

987.6 49.86 -0.013

1254.5 48.54 0.028

1401.3 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. 

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.
Page 768 of 903

(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.

232. 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:

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
Page 769 of 903

98575 0.06383 12.58

8.314472 323.5

n



 





n&= 29.428 mol/s

* * * * *

(c) CFV molar flow rate. Some CFV flow meters consist of a single venturi and some 

consist of multiple venturis, where different combinations of venturis are used to meter 

different flow rates. If you use multiple venturis and you calibrated each venturi 

independently to determine a separate discharge coefficient, Cd (or calibration coefficient,

Kv), for each venturi, calculate the individual molar flow rates through each venturi and 

sum all their flow rates to determine n . If you use multiple venturis and you calibrated 

each combination of venturis, calculate n using the sum of the active venturi throat areas 

as At, the square root of the sum of the squares of the active venturi throat diameters as dt, 

and the ratio of the venturi throat to inlet diameters as the ratio of the square root of the 

sum of the active venturi throat diameters (dt) to the diameter of the common entrance to 

all 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 §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:
Page 770 of 903

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

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

233. 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.
Page 771 of 903

(a) Vapor pressure of water. Calculate the vapor pressure of water for a given saturation 

temperature condition, Tsat, as follows, or use good engineering judgment to use a 

different relationship of the vapor pressure of water to a given saturation temperature 

condition:

(1) For humidity measurements made at ambient temperatures from (0 to 100) °C, or for 

humidity measurements made over super-cooled water at ambient temperatures from (–

50 to 0) °C, use the following equation:

sat

sat

8.2969 1

sat 4 273.16

10 H2O 10

sat

273.16 4.76955 1

3

273.16 log ( ) 10.79574 1 5.02800 log 1.50475 10 1 10

273.16

0.42873 10 10 1 0.2138602

T

T

T

p

T

 

   

  

 

   

  

     

                     

 

      

 

Eq. 1065.645-1

Where:

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 772 of 903

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

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

234. 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 
Page 773 of 903

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.

* * * * *

235. 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.
Page 774 of 903

KH2Ogas = water-gas reaction equilibrium coefficient. You may use 3.5 or calculate your 

own value using good engineering judgment.

xH2Oexhdry = amount of H2O in exhaust per dry mole of dry exhaust.

xprod/intdry = amount of dry stoichiometric products per dry mole of intake air.

xdil/exhdry = amount of dilution gas and/or excess air per mole of dry exhaust.

xint/exhdry = amount of intake air required to produce actual combustion products per mole 

of dry (raw or diluted) exhaust.

xraw/exhdry = amount of undiluted exhaust, without excess air, per mole of dry (raw or 

diluted) exhaust.

xO2int = amount of intake air O2 per mole of intake air.

xCO2intdry = amount of intake air CO2 per mole of dry intake air. You may use xCO2intdry = 

375 μmol/mol, but we recommend measuring the actual concentration in the intake air.

xH2Ointdry = amount of intake air H2O per mole of dry intake air.

xCO2int = amount of intake air CO2 per mole of intake air.

xCO2dil = amount of dilution gas CO2 per mole of dilution gas.

xCO2dildry = amount of dilution gas CO2 per mole of dry dilution gas. If you use air as 

diluent, you may use xCO2dildry = 375 μmol/mol, but we recommend measuring the actual 

concentration in the intake air.

xH2Odildry = amount of dilution gas H2O per mole of dry dilution gas.

xH2Odil = amount of dilution gas H2O per mole of dilution gas.

x[emission]meas = amount of measured emission in the sample at the respective gas analyzer.

x[emission]dry = amount of emission per dry mole of dry sample.

xH2O[emission]meas = amount of H2O in sample at emission-detection location. Measure or 

estimate these values according to §1065.145(e)(2).

xH2Oint = amount of H2O in the intake air, based on a humidity measurement of intake air.

 = atomic hydrogen-to-carbon ratio of the mixture of fuel(s) being combusted, weighted 

by molar consumption.

 = atomic oxygen-to-carbon ratio of the mixture of fuel(s) being combusted, weighted 

by molar consumption.

 = atomic sulfur-to-carbon ratio of the mixture of fuel(s) being combusted, weighted by 

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 775 of 903

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 776 of 903

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

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.
Page 777 of 903

wN = nitrogen mass fraction of fuel.

Example:

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

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 steadystate testing. See §1065.915(d)(5)(iv) for application to field testing.

(1) Crankcase flow rate. If engines are not subject to crankcase controls under the 

standard-setting part, you may calculate raw exhaust flow based on int n or mfuel  using one 

of the following:

(i) You may measure flow rate through the crankcase vent and subtract it from the 

calculated exhaust flow.
Page 778 of 903

(ii) You may estimate flow rate through the crankcase vent by engineering analysis as 

long as the uncertainty in your calculation does not adversely affect your ability to show 

that your engines comply with applicable emission standards.

(iii) You may assume your crankcase vent flow rate is zero.

(2) Intake air molar flow rate calculation. Calculate exh n based on int n using the following 

equation:

 

 

int

exh

int/exhdry raw/exhdry

H2Oexhdry

1

1

n

n

x x

x



  

  



 





Eq. 1065.655-24

Where:

exh n = raw exhaust molar flow rate from which you measured emissions.

int n = intake air molar flow rate including humidity in intake air.

Example:

int n = 3.780 mol/s

xint/exhdry = 0.69021 mol/mol

xraw/exhdry = 1.10764 mol/mol

xH20exhdry = 107.64 mmol/mol = 0.10764 mol/mol

 

 

exh

3.780

0.69021 1.10764

1

1 0.10764

n 

  

  

  



exh n = 6.066 mol/s

(3) Fuel mass flow rate calculation. This calculation may be used only for steady-state 

laboratory testing. See §1065.915(d)(5)(iv) for application to field testing. Calculate 

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

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
Page 779 of 903

 

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

236. 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 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.

* * * * *

237. 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 
Page 780 of 903

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

Where:

xTHCE = The sum of the C1-equivalent concentrations of non-oxygenated hydrocarbons, 

alcohols, and aldehydes.

xNOTHC = The sum of the C1-equivalent concentrations of NOTHC.

xOHCi = The C1-equivalent concentration of oxygenated species i in diluted exhaust, not 

corrected for initial contamination.

xOHCi-init = The C1-equivalent concentration of the initial system contamination (optional) 

of oxygenated species i, dry-to-wet corrected. 

xTHC[THC-FID]cor = The C1-equivalent response to NOTHC and all OHC in diluted exhaust, 

HC contamination and dry-to-wet corrected, as measured by the THC-FID.

RFOHCi[THC-FID] = The response factor of the FID to species i relative to propane on a C1-

equivalent basis.

C

#

= the mean number of carbon atoms in the particular compound.

Mdexh = The molar mass of diluted exhaust as determine in §1065.340.

mdexhOHCi = The mass of oxygenated species i in dilute exhaust.

MOHCi = The C1-equivalent molecular weight of oxygenated species i.

mdexh = The mass of diluted exhaust

ndexhOHCi = The number of moles of oxygenated species i in total diluted exhaust flow.

ndexh = The total diluted exhaust flow.

(b) If we require you to determine nonmethane hydrocarbon equivalent (NMHCE), use 

the following equation:

xNMHCE = xTHCE – RFCH4[THC-FID]  xCH4

Eq. 1065.665-4

Where:

xNMHCE = The sum of the C1-equivalent concentrations of nonoxygenated nonmethane 

hydrocarbon (NONMHC), alcohols, and aldehydes.

RFCH4[THC-FID] = response factor of THC-FID to CH4.

xCH4 = concentration of CH4, HC contamination (optional) and dry-to-wet corrected, as 

measured by the gas chromatograph FID.

(c) The following example shows how to determine NMHCE emissions based on ethanol 

(C2H5OH), methanol (CH3OH), acetaldehyde (C2H4O), and formaldehyde (HCHO) as 
Page 781 of 903

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

238. Section 1065.695 is amended by revising paragraph (c)(4)(i) and adding 

paragraph (c)(6)(x) to read as follows:

§1065.695 Data requirements.

* * * * *

(c) * * *

(4) * * *

(i) Linearity verification.

* * * * *

(6) * * *

(x) Number and type of preconditioning cycles.

* * * * *

Subpart H—[Amended]

239. 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 
Page 782 of 903

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:

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.

240. Section 1065.703 is amended by revising Table 1 to read as follows:

§1065.703 Distillate diesel fuel.

* * * * *
Page 783 of 903

Table 1 of §1065.703–Test fuel specifications for distillate diesel fuel

Property Unit Ultra Low

Sulfur

Low

Sulfur

High

Sulfur

Reference

Procedure1

Cetane Number — 40 - 50 40 - 50 40 - 50 ASTM D613

Distillation range:

Initial boiling point

10 pct. point 

50 pct. point

90 pct. point 

Endpoint

°C

171 - 204

204 - 238

243 - 282

293 - 332

321 - 366

171 - 204

204 - 238

243 - 282

293 - 332

321 - 366

171 - 204

204 - 238

243 - 282

293 - 332

321 - 366

ASTM D86

Gravity °API 32 - 37 32 - 37 32 - 37 ASTM D4052

Total sulfur, ultra low sulfur mg/kg 7 – 15 See 40 CFR 80.580

Total sulfur, low and high sulfur mg/kg 300 - 500 800 - 2500 ASTM D2622or 

alternates as allowed 

under 40 CFR 

80.580

Aromatics, min. (Remainder shall be 

paraffins, naphthenes, and olefins)

g/kg 100 100 100 ASTM D5186

Flashpoint, min. °C 54 54 54 ASTM D93

Kinematic Viscosity cSt 2.0 - 3.2 2.0 - 3.2 2.0 - 3.2 ASTM D445

1ASTM procedures are incorporated by reference in §1065.1010. See §1065.701(d) for other allowed 

procedures.

241. Section 1065.710 is revised to read as follows:

§1065.710 Gasoline.

(a) This section specifies test fuel properties for gasoline with ethanol (low-level blend 

only) and for gasoline without ethanol. Note that the “fuel type” for the fuels specified in 

paragraphs (b) and (c) of this section is considered to be gasoline. In contrast, fuels with 

higher ethanol concentrations, such as fuel containing 82 percent ethanol, are considered 

to be ethanol fuels rather than gasoline. We specify some test fuel parameters that apply

uniquely for low-temperature testing and for testing at altitudes above 1,219 m. For all 

other testing,, use the test fuel parameters specified for general testing. Unless the 

standard-setting part specifies otherwise, use the fuel specified in paragraph (c) of this 

section for general testing. 

(b) The following specifications apply for a blended gasoline test fuel that has nominally

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 Reference 

Procedure1
Page 784 of 903

General 

Testing

LowTemperature 

Testing

High Altitude 

Testing

Antiknock Index 

(R+M)/2 - 87.0 - 88.42 87.0 Minimum

ASTM D2699 and 

D2700

Sensitivity (R-M) - 7.5 Minimum ASTM D2699 and 

D2700

Dry Vapor Pressure 

Equivalent (DVPE)

3 kPa (psi) 60.0-63.4 

(8.7-9.2)

77.2-81.4

(11.2-11.8)

52.4-55.2 

(7.6-8.0) ASTM D5191

Distillation

10% evaporated °C (°F) 49-60(120-140)

43-54 

(110-130)

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 milliliter 2.0 Maximum

Total Aromatic 

Hydrocarbons volume % 19.5-24.5

ASTM D5769

C6 Aromatics 

(benzene) volume % 0.6-0.8

C7 Aromatics 

(toluene) volume % 4.4-5.5

C8 Aromatics volume % 5.5-6.9

C9 Aromatics volume % 5.0-6.2

C10+ Aromatics volume % 4.0-5.0

Olefins4 mass % 4.5-11.5 ASTM D6550

Ethanol blended5volume % 14.6-15.0

See paragraph 

(b)(3) of this 

section.

Ethanol 

confirmatory

6,7 volume % 14.3-15.3 ASTM D5599

Total Content of 

Oxygenates Other 

than Ethanol7

volume % 0.1 Maximum ASTM D5599

Sulfur mg/kg 8.0-11.0 ASTM D2622, 

D5453 or D7039

Lead g/liter 0.0026 Maximum ASTM D3237

Phosphorus g/liter 0.0013 Maximum ASTM D3231

Copper Corrosion - No. 1 Maximum ASTM D130

Solvent-Washed Gum 

Content

mg/100 

milliliter 3.0 Maximum ASTM D381

Oxidation Stability minute 1000 Minimum ASTM D525

1ASTM procedures are incorporated by reference in §1065.1010. See §1065.701(d) for other allowed

procedures.

2Octane specifications apply only for testing related to exhaust emissions. For engines or vehicles that require 

the use of premium fuel, as described in paragraph (d) of this section, the adjusted specification for antiknock 

index is a minimum value of 91.0; no maximum value applies. All other specifications apply for this highoctane 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.
Page 785 of 903

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

Property Unit SPECIFICATION Reference 

Procedure1 General Testing Low-Temperature Testing

Distillation 

Range:

Evaporated 

initial boiling 

point

10% 

evaporated

50% 

evaporated

90% 

evaporated

Evaporated 

final boiling 

point

°C

24 - 35 2

49 - 57

93 - 110

149 - 163

Maximum, 213

24 - 36

37 - 48

82 - 101

158 - 174

Maximum, 212

ASTM D86

Hydrocarbon 

composition:

Olefins

Aromatics

Saturates

volume % Maximum, 0.10

Maximum, 0.35

Remainder

Maximum, 0.175

Maximum, 0.304

Remainder

ASTM D1319

Lead g/liter Maximum, 0.013 Maximum, 0.013 ASTM D3237

Phosphorous g/liter Maximum, 0.0013 Maximum, 0.005 ASTM D3231

Total sulfur mg/kg Maximum, 80 Maximum, 80 ASTM D2622

Dry vapor 

pressure 

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 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.
Page 786 of 903

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.

242. Section 1065.715 is amended by revising paragraph (a) to read as follows:

§1065.715 Natural gas.

(a) Except as specified in paragraph (b) of this section, natural gas for testing must meet 

the specifications in the following table:

Table 1 of §1065.715–Test fuel specifications for natural gas

Property Value1

Methane, CH4 Minimum, 0.87 mol/mol

Ethane, C2H6 Maximum, 0.055 mol/mol

Propane, C3H8 Maximum, 0.012 mol/mol

Butane, C4H10 Maximum, 0.0035 mol/mol

Pentane, C5H12 Maximum, 0.0013 mol/mol

C6 and higher Maximum, 0.001 mol/mol

Oxygen Maximum, 0.001 mol/mol

Inert gases (sum of CO2 and N2) Maximum, 0.051 mol/mol

1 Demonstrate compliance with fuel specifications based on the reference 

procedures in ASTM D1945 (incorporated by reference in §1065.1010), or on 

other measurement procedures using good engineering judgment. See 

§1065.701(d) for other allowed procedures.

* * * * *

243. Section 1065.720 is amended by revising paragraph (a) to read as follows:

§1065.720 Liquefied petroleum gas.

(a) Except as specified in paragraph (b) of this section, liquefied petroleum gas for testing 

must meet the specifications in the following table:

Table 1 of §1065.720–Test fuel specifications for liquefied petroleum gas

Property Value Reference Procedure1

Propane, C3H8 Minimum, 0.85 m3/m3 ASTM D2163

Vapor pressure at 38 °C Maximum, 1400 kPa ASTM D1267or 25982

Volatility residue (evaporated temperature, 35 °C) Maximum, -38 °C ASTM D1837

Butanes Maximum, 0.05 m3/m3 ASTM D2163

Butenes Maximum, 0.02 m3/m3 ASTM D2163

Pentenes and heavier Maximum, 0.005 m3/m3 ASTM D2163

Propene Maximum, 0.1 m3/m3 ASTM D2163

Residual matter (residue on 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.

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.
Page 787 of 903

* * * * *

244. 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.

245. 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) * * *

(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.
Page 788 of 903

(2) Use the following gases with a FID analyzer:

(i) FID fuel. Use FID fuel with a stated H2 concentration of (0.39 to 0.41) mol/mol, 

balance He or N2, and a stated total hydrocarbon concentration of 0.05 mol/mol or less. 

For GC-FIDs that measure methane (CH4) using a FID fuel that is balance N2, perform 

the CH4 measurement as described in SAE J1151 (incorporated by reference in 

§1065.1010).

(ii) FID burner air. Use FID burner air that meets the specifications of purified air in 

paragraph (a)(1) of this section. For field testing, you may use ambient air.

(iii) FID zero gas. Zero flame-ionization detectors with purified gas that meets the 

specifications in paragraph (a)(1) of this section, except that the purified gas O2

concentration may be any value. Note that FID zero balance gases may be any

combination of purified air and purified nitrogen. We recommend FID analyzer zero 

gases that contain approximately the expected flow-weighted mean concentration of O2

in the exhaust sample during testing.

(iv) FID propane span gas. Span and calibrate THC FID with span concentrations of 

propane, C3H8. Calibrate on a carbon number basis of one (C1). For example, if you use 

a C3H8 span gas of concentration 200 mol/mol, span a FID to respond with a value of 

600 mol/mol. Note that FID span balance gases may be any combination of purified air 

and purified nitrogen. We recommend FID analyzer span gases that contain 

approximately the flow-weighted mean concentration of O2 expected during testing. If 

the expected O2 concentration in the exhaust sample is zero, we recommend using a 

balance gas of purified nitrogen.

(v) FID CH4 span gas. If you always span and calibrate a CH4 FID with a nonmethane 

cutter, then span and calibrate the FID with span concentrations of CH4. Calibrate on a 

carbon number basis of one (C1). For example, if you use a CH4 span gas of 

concentration 200 mol/mol, span a FID to respond with a value of 200 mol/mol. Note 

that FID span balance gases may be any combination of purified air and purified 

nitrogen. We recommend FID analyzer span gases that contain approximately the 

expected flow-weighted mean concentration of O2 in the exhaust sample during testing. 

If the expected O2 concentration in the exhaust sample is zero, we recommend using a 

balance gas of purified nitrogen.

(3) Use the following gas mixtures, with gases traceable within ±1 % of the NISTaccepted value or other gas standards we approve:

(i) CH4, balance purified air and/or N2 (as applicable).

(ii) C2H6, balance purified air and/or N2 (as applicable).

(iii) C3H8, balance purified air and/or N2 (as applicable).

(iv) CO, balance purified N2.

(v) CO2, balance purified N2.

(vi) NO, balance purified N2.

(vii)) NO2, balance purified air.

(viii) O2, balance purified N2.

(ix) C3H8, CO, CO2, NO, balance purified N2.

(x) C3H8, CH4, CO, CO2, NO, balance purified N2.

(xi) N2O, balance purified air and/or N2 (as applicable).

* * * * *
Page 789 of 903

(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]

246. 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).

* * * * *

247. 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 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

* * * * *
Page 790 of 903

248. 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]

249. 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:

§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.

* * * * *

250. 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:

Symbol Quantity Unit Unit symbol Units in terms of SI 

base units

 atomic hydrogen to carbon ratio mole per mole mol/mol 1

A area square meter m

2 m2

A0intercept of least squares regression

A1 slope of least squares regression

 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

DR dilution ratio mole per mol mol/mol 1
Page 791 of 903



error between a quantity and its 

reference

e

brake-specific emission or fuel 

consumption gram per kilowatt hour g/(kW∙hr) g∙3.6-1

∙106∙m-2∙kg∙s2

F F-test statistic

f frequency hertz Hz s

-1

fn angular speed (shaft) revolutions per minute r/min 2∙π∙60-1∙m·m-1·s-1

 ratio of specific heats

(joule per kilogram 

kelvin) per (joule per 

kilogram kelvin) 

(J/(kg∙K))/(J/(kg∙K)) 1

K correction factor 1

Kv calibration coefficient m

4

∙s∙K0.5/kg m

4

∙s∙K0.5∙kg-1

l length meter m m

 viscosity, dynamic pascal second Pa∙s m

-1

∙kg∙s-1

M molar mass1gram per mole g/mol 10-3∙kg∙mol-1

m mass kilogram kg kg

m mass rate kilogram per second kg/s kg∙s-1

 viscosity, kinematic meter squared per 

second m

2

/s m

2

∙s-1

N total number in series

n amount of substance mole mol mol

n amount of substance rate mole per second mol/s mol∙s-1

P power kilowatt kW 103∙m2∙kg∙s-3

PF penetration fraction

p pressure pascal Pa m

-1

∙kg∙s-2

 mass density kilogram per cubic 

meter kg/m3

kg∙m-3

r ratio of pressures pascal per pascal Pa/Pa 1

R

2

coefficient of determination

Ra average surface roughness micrometer m 10-6 m

Re# Reynolds number

RF response factor

RH relative humidity

 non-biased standard deviation

S Sutherland constant kelvin K K

SEE standard estimate of error

T absolute temperature kelvin K K

T Celsius temperature degree Celsius °C K-273.15

T torque (moment of force) newton meter N∙m m

2

∙kg∙s-2

t time second s s

t time interval, period, 1/frequency second s s

V volume cubic meter m

3 m3

V

 volume rate cubic meter per second m

3

/s m

3

∙s-1

W work kilowatt hour kW∙hr 3.6∙10-6∙m2∙kg∙s-2

wc carbon mass fraction gram per gram g/g 1

x amount of substance mole 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. 

[NOTE TO EDITOR: The current CFR has incorrect rendering of nand mand V



. Please 

make sure the final published characters are properly displayed. Also, all the symbols in 

the first column should be in italic font (except the subscripts); this is also incorrect for 

the Greek letters in the current CFR.]
Page 792 of 903

* * * * * 

(f) * * *

(2) This part uses the following molar masses or effective molar masses of chemical 

species:

Symbol Quantity g/mol

(10-3·kg·mol-1)

Mair molar mass of dry air128.96559

MAr molar mass of argon 39.948

MC molar mass of carbon 12.0107

MCH3OH molar mass of methanol 32.04186

MC2H5OH molar mass of ethanol 46.06844

MC2H4O molar mass of acetaldehyde 44.05256

MC3H8 molar mass of propane 44.09562

MC3H7OH molar mass of propanol 60.09502

MCO molar mass of carbon monoxide 28.0101

MCH4 molar mass of methane 16.0425

MCO2 molar mass of carbon dioxide 44.0095

MH molar mass of atomic hydrogen 1.00794

MH2 molar mass of molecular hydrogen 2.01588

MH2O molar mass of water 18.01528

MHCHO molar mass of formaldehyde 30.02598

MHe molar mass of helium 4.002602

MN molar mass of atomic nitrogen 14.0067

MN2 molar mass of molecular nitrogen 28.0134

MNH3 molar mass of ammonia 17.03052

MNMHC effective C1 molar mass of nonmethane hydrocarbon213.875389

MNMHCE

effective C1 molar mass of nonmethane hydrocarbon 

equivalent2 13.875389

MNOx effective molar mass of oxides of nitrogen346.0055

MN2O molar mass of nitrous oxide 44.0128

MO molar mass of atomic oxygen 15.9994

MO2 molar mass of molecular oxygen 31.9988

MS molar mass of sulfur 32.065

MTHC effective C1 molar mass of total hydrocarbon213.875389

MTHCE effective C1 molar mass of total hydrocarbon equivalent213.875389

1

See paragraph (f)(1) of this section for the composition of dry air.

2The effective molar masses of THC, THCE, NMHC, and NMHCE are defined on a C1 basis and 

are based on an atomic hydrogen-to-carbon ratio, , of 1.85 (with β, γ, and δ equal to zero).

3The effective molar mass of NOx

is defined by the molar mass of nitrogen dioxide, NO2.

* * * * *

251. 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.
Page 793 of 903

(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.

(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.
Page 794 of 903

(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.

(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.

(2) SAE J1151, Methane Measurement Using Gas Chromatography, Revised September 

2011, IBR approved for §§1065.267 and 1065.750.

252. A new subpart L is added to read as follows:

Subpart L—Methods for Unregulated and Special Pollutants

Sec.
Page 795 of 903

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 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.
Page 796 of 903

(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.

(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.
Page 797 of 903

(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 

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.
Page 798 of 903

(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.

(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 pre-cleaned 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.

(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 
Page 799 of 903

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 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.
Page 800 of 903

(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 threeball 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, 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 
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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 KudernaDanish 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:

(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.
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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.

253. 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.

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.

1066.245 Response time verification.

1066.250 Base inertia verification.

1066.255 Parasitic loss verification.
Page 803 of 903

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.

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.
Page 804 of 903

1066.835 AC17 Air conditioning efficiency test procedure.

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. 

(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 standard-setting 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.
Page 805 of 903

(a) You are responsible for statements and information in your applications for 

certification, requests for approved procedures, selective enforcement audits, laboratory

audits, production-line test reports, or any other statements you make to us related to this 

part 1066. If you provide statements or information to someone for submission to EPA, 

you are responsible for these statements and information as if you had submitted them to 

EPA yourself.

(b) In the standard-setting part and in 40 CFR 1068.101, we describe your obligation to 

report truthful and complete information and the consequences of failing to meet this 

obligation. See also 18 U.S.C. 1001 and 42 U.S.C. 7413(c)(2). This obligation applies 

whether you submit this information directly to EPA or through someone else.

(c) We may void any certificates or approvals associated with a submission of 

information if we find that you intentionally submitted false, incomplete, or misleading 

information. For example, if we find that you intentionally submitted incomplete 

information to mislead EPA when requesting approval to use alternate test procedures, 

we may void the certificates for all engine families certified based on emission data 

collected using the alternate procedures. This would also apply if you ignore data from 

incomplete tests or from repeat tests with higher emission results.

(d) We may require an authorized representative of your company to approve and sign 

the submission, and to certify that all the information submitted is accurate and complete. 

This includes everyone who submits information, including manufacturers and others.

(e) See 40 CFR 1068.10 for provisions related to confidential information. Note however 

that under 40 CFR 2.301, emission data are generally not eligible for confidential 

treatment.

(f) Nothing in this part should be interpreted to limit our ability under Clean Air Act 

section 208 (42 U.S.C. 7542) to verify that vehicles conform to the regulations.

§1066.5 Overview of this part 1066 and its relationship to the standard-setting part.

(a) This part specifies procedures that can apply generally to testing various categories of 

vehicles. See the standard-setting part for directions in applying specific provisions in 

this part for a particular type of vehicle. Before using this part’s procedures, read the 

standard-setting part to answer at least the following questions:

(1) What drive schedules must I use for testing?

(2) Should I warm up the test vehicle before measuring emissions, or do I need to 

measure cold-start emissions during a warm-up segment of the duty cycle?

(3) Which exhaust constituents do I need to measure? Measure all exhaust constituents 

that are subject to emission standards, any other exhaust constituents needed for 

calculating emission rates, and any additional exhaust constituents as specified in the 

standard-setting part. See 40 CFR 1065.5 regarding requests to omit measurement of 

N2O and CH4 for vehicles, not subject to 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]
Page 806 of 903

(9) Are there any emission standards specified at particular operating conditions or 

ambient conditions?

(10) Do any unique requirements apply for durability testing?

(b) The testing specifications in the standard-setting part may differ from the 

specifications in this part. In cases where it is not possible to comply with both the 

standard-setting part and this part, you must comply with the specifications in the 

standard-setting part. The standard-setting part may also allow you to deviate from the 

procedures of this part for other reasons.

(c) The following table shows how this part divides testing specifications into subparts:

Table 1 of §1066.5—Description of Part 1066 subparts.

This subpart Describes these specifications or procedures

Subpart A Applicability and general provisions.

Subpart B Equipment for testing.

Subpart C Dynamometer specifications.

Subpart D Coastdowns for testing.

Subpart E How to prepare your vehicle and run an emission test.

Subpart F How to test hybrid vehicles.

Subpart G Test procedure calculations.

Subpart H Cold temperature testing.

Subpart I Exhaust emission test procedures for motor vehicles.

Subpart J Reserved.

Subpart K Definitions and reference material.

§1066.10 Other procedures.

(a) Your testing. The procedures in this part apply for all testing you do to show 

compliance with emission standards, with certain exceptions noted in this section. In 

some other sections in this part, we allow you to use other procedures (such as less 

precise or less accurate procedures) if they do not affect your ability to show that your 

vehicles comply with the applicable emission standards. This generally requires emission 

levels to be far enough below the applicable emission standards so that any errors caused 

by greater imprecision or inaccuracy do not affect your ability to state unconditionally

that the engines meet all applicable emission standards.

(b) Our testing. These procedures generally apply for testing that we do to determine if 

your vehicles comply with applicable emission standards. We may perform other testing 

as allowed by the Act.

(c) Exceptions. We may allow or require you to use procedures other than those 

specified in this part as described in 40 CFR 1065.10(c). All the test procedures noted as 

exceptions to the specified procedures are considered generically as "other procedures." 

Note that the terms "special procedures" and "alternate procedures" have specific 

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:
Page 807 of 903

(1) Total oxides of nitrogen, NOx.

(2) Hydrocarbons, HC, which may be expressed in the following ways:

(i) Total hydrocarbons, THC.

(ii) Nonmethane hydrocarbons, NMHC, which results from subtracting methane (CH4) 

from THC.

(iii) Total hydrocarbon-equivalent, THCE, which results from adjusting THC 

mathematically to be equivalent on a carbon-mass basis.

(iv) Nonmethane hydrocarbon-equivalent, NMHCE, which results from adjusting NMHC 

mathematically to be equivalent on a carbon-mass basis.

(v) Nonmethane organic gases, NMOG, which are calculated either from fully or partially

speciated measurement of hydrocarbons including oxygenates, or by adjusting measured 

NMHC values based on fuel oxygenate properties.

(3) Particulate 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 distance-based 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 (raw or dilute) flow from which it was 
Page 808 of 903

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 %.

(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.
Page 809 of 903

(f) Interpretation of ranges. Interpret a range as a tolerance unless we explicitly identify

it as an accuracy, repeatability, linearity, or noise specification. See 40 CFR 1065.1001 

for the definition of tolerance. In this part, we specify two types of ranges:

(1) Whenever we specify a range by a single value and corresponding limit values above 

and below that value (such as X ±Y), target the associated control point to that single 

value (X). Examples of this type of range include “±10 % of maximum pressure”, or 

“(30 ±10) kPa”. In these examples, you would target the maximum pressure or 30 kPa, 

respectively.

(2) Whenever we specify a range by the interval between two values, you may target any 

associated control point to any value within that range. An example of this type of range 

is “(40 to 50) kPa”.

(g) Scaling of specifications with respect to an applicable standard. Because this part 

1066 applies to a wide range of vehicles and emission standards, some of the 

specifications in this part are scaled with respect to a vehicle’s applicable standard or 

weight. This ensures that the specification will be adequate to determine compliance, but 

not overly burdensome by requiring unnecessarily high-precision equipment. Many of 

these specifications are given with respect to a “flow-weighted mean” that is expected at 

the standard or during testing. Flow-weighted mean is the mean of a quantity after it is 

weighted proportional to a corresponding flow rate. For example, if a gas concentration 

is measured continuously from the raw exhaust of an engine, its flow-weighted mean 

concentration is the sum of the products of each recorded concentration times its 

respective exhaust flow rate, divided by the sum of the recorded flow rates. As another 

example, the bag concentration from a CVS system is the same as the flow-weighted 

mean concentration, because the CVS system itself flow-weights the bag concentration.

§1066.25 Recordkeeping.

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 810 of 903

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.

(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 
Page 811 of 903

fan configuration is impractical for special vehicle designs, such as vehicles with rearmounted engines, or it does not provide adequate cooling to properly represent in-use 

operation, you may ask us to approve increasing 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.

(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.
Page 812 of 903

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 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 m3/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.
Page 813 of 903

(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:

(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 smoothwalled.) 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.
Page 814 of 903

(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:

(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 
Page 815 of 903

(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.

(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:

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.
Page 816 of 903

This section specifies criteria that your test system must meet for updating and recording 

data. It also specifies criteria for controlling the systems related to driver demand, the 

dynamometer, sampling equipment, and measurement instruments.

(a)(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

Applicable 

Section Measured Values

Minimum 

Command and 

Control 

Frequency

Minimum 

Recording 

Frequencya

§1066.310

§1066.320 Vehicle speed — 10 Hz

§1066.430 Continuous concentrations of raw or dilute 

analyzers — 1 Hz

§1066.430

§1066.501 Power analyzerb — 1 Hz

§1066.430 Bag concentrations of raw or dilute analyzers —

1 mean value 

per test interval

40 CFR 1065.545

§1066.430

Diluted exhaust flow rate from a CVS with a 

heat exchanger upstream of the flow

measurement

— 1 Hz

40 CFR 1065.545

§1066.430

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

§1066.430

Dilution air flow if actively controlled (for 

example, a partial-flow PM sampling system) 5 Hz 1 Hz means

40 CFR 1065.545

§1066.430

Sample flow from a CVS that has a heat 

exchanger 1 Hz 1 Hz

40 CFR 1065.545

§1066.430

Sample flow from a CVS that does not have a 

heat exchanger 5 Hz 1 Hz means

§1066.425 Ambient temperature — 1 Hz

§1066.425 Ambient humidity — 1 Hz

§1066.425 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 
Page 817 of 903

values at a rate of 1 Hz.

b

For power analyzers’ sampling frequency, follow SAE J1711 (incorporated by reference in §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 818 of 903

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 

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 
Page 819 of 903

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 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.
Page 820 of 903

(b) Scope and frequency. Perform this calibration while the flow meter is installed in its 

permanent position, except as allowed in paragraph (c) of this section. Perform this 

calibration after you change any part of the flow configuration upstream or downstream 

of the flow meter that may affect the flow-meter calibration. Perform this calibration 

upon initial CVS installation and whenever corrective action does not resolve a failure to 

meet the diluted exhaust flow verification (i.e., propane check) in 40 CFR 1065.341.

(c) Ex-situ CFV and SSV calibration. You may remove a CFV or SSV from its 

permanent position for calibration as long as the flow meter meets the requirements in 40 

CFR 1065.340(c).

(d) Reference flow meter. Calibrate each CVS flow meter using a reference flow meter 

such as a subsonic venturi flow meter, a long-radius ASME/NIST flow nozzle, a smooth 

approach orifice, a laminar flow element, 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 .

(iv) The mean static absolute pressure at the PDP outlet, out p .

(v) The mean PDP speed, nPDP f .
Page 821 of 903

(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 as follows:

(1) Configure your calibration system as shown in Figure 1 of this section.

(2) Verify that any leaks between the calibration flow meter and the SSV are less than 0.3 

% of the total flow at the highest restriction.

(3) Start the blower downstream of the SSV.

(4) While the SSV operates, maintain a constant temperature at the SSV inlet within ±2 

% of the mean absolute inlet temperature, Tin.

(5) Set the variable restrictor or variable-speed blower to a flow rate greater than the 

greatest flow rate expected during testing. You may not extrapolate flow rates beyond 

calibrated values, so we recommend that you make sure the Reynolds number, Re#, at the 

SSV throat at the greatest calibrated flow rate is greater than the maximum Re#expected 

during testing.

(6) Operate the SSV for at least 3 min to stabilize the system. Continue operating the 

SSV and record the mean of at least 30 seconds of sampled data of each of the following 

quantities:

(i) The mean flow rate of the reference flow meter,Qref



. This may include several 

measurements of different quantities for calculating Qref



, such as reference meter 

pressures and temperatures.

(ii) The mean temperature at the venturi inlet, Tin.

(iii) The mean static absolute pressure at the venturi inlet, in p.

(iv) Mean static differential pressure between the static pressure at the venturi inlet and 

the static pressure at the venturi throat, SSV p.

(7) Incrementally close the restrictor valve or decrease the blower speed to decrease the

flow rate.

(8) Repeat the steps in paragraphs (g)(6) and (7) of this section to record data at a 

minimum of ten flow rates.
Page 822 of 903

(9) Determine an equation to quantify Cd as a function of Re#by using the collected data 

and the equations in §1066.650(b). Section 1066.650 also includes statistical criteria for 

validating the Cd versus Re#equation.

(10) Verify the calibration by performing a CVS verification (i.e., propane check) as 

described in 40 CFR 1065.341 using the Cd versus Re#equation.

(11) Use the SSV only between the minimum and maximum calibrated flow rates. If you 

want to use the SSV at a higher or lower flow rate, you must recalibrate the SSV.

(12) Use the equations in §1066.652(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.

(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.
Page 823 of 903

(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.

(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
Page 824 of 903

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

§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

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 
Page 825 of 903

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 road-load forces corresponding to maximum road load conditions and maximum 

simulated inertia at the highest acceleration rate experienced during testing.

(d) Component requirements. The following specifications apply:

(1) The nominal roll diameter must be 120 cm or greater. The dynamometer must have 

an independent drive roll for each drive axle as tested under §1066.410(g), except that 

two drive axles may share a single drive roll. Use good engineering judgment to ensure 

that the dynamometer roll diameter is large enough to provide sufficient tire-roll contact 

area to avoid tire overheating and power losses from tire-roll slippage.

(2) Measure and record force and speed at 10 Hz or faster. You may convert measured 

values to 1-Hz, 2-Hz, or 5-Hz values before your calculations, using good engineering 

judgment.

(3) The load applied by the dynamometer simulates forces acting on the vehicle during 

normal driving according to the following equation:

2 i i-1

i i i

i i-1

v v FR A B v C v M

t t



    



Eq. 1066.210-1

Where:

FR = total road-load force to be applied at the surface of the roll. The total force is the 

sum of the individual tractive forces applied at each roll surface.

i = a counter to indicate a point in time over the driving schedule. For a dynamometer 

operating at 10-Hz intervals over a 600-second driving schedule, the maximum value of i

should be 6,000.

A = a vehicle-specific constant value representing the vehicle’s frictional load in lbf or 

newtons. See subpart D of this part.

B = a vehicle-specific coefficient representing load from drag and rolling resistance, 

which are a function of vehicle speed, in lbf/mph or N∙s/m. See subpart D of this part.

v = linear speed at the roll surfaces as measured by the dynamometer, in mph or m/s. Let 

vi-1 = 0 for i = 0.
Page 826 of 903

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.

(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 827 of 903

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 coastdown 

verification

Upon initial installation, within 7 days of testing, and after 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.
Page 828 of 903

(a) Scope and frequency. Perform linearity verification for dynamometer speed and 

torque at least as frequently as indicated in Table 1 of §1066.215. The intent of linearity

verification is to determine that the system responds accurately and proportionally over 

the measurement range of interest. Linearity verification generally consists of 

introducing a series of at least 10 reference values to a measurement system. The 

measurement system quantifies each reference value. The measured values are then 

collectively compared to the reference values by using a least-squares linear regression 

and the linearity criteria specified in Table 1 of this section.

(b) Performance requirements. If a measurement system does not meet the applicable 

linearity criteria in Table 1 of this section, correct the deficiency by re-calibrating, 

servicing, or replacing components as needed. Repeat the linearity verification after 

correcting the deficiency to ensure that the measurement system meets the linearity

criteria. Before you may use a measurement system that does not meet linearity criteria, 

you must demonstrate to us that the deficiency does not adversely affect your ability to 

demonstrate compliance with the applicable standards.

(c) Procedure. Use the following linearity verification protocol, or use good engineering 

judgment to develop a different protocol that satisfies the intent of this section, as 

described in paragraph (a) of this section:

(1) In this paragraph (c), the letter “y” denotes a generic measured quantity, the 

superscript over-bar denotes an arithmetic mean (such as y ), and the subscript “ref” 

denotes the known or reference quantity being measured.

(2) Operate the dynamometer system at the specified operating conditions. This may

include any specified adjustment or periodic calibration of the dynamometer system.

(3) Set dynamometer speed and torque to zero.

(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.
Page 829 of 903

(11) Repeat the steps in paragraphs (c)(8) though (10) of this section until you measure 

speeds and torques at each of the reference settings.

(12) Use the arithmetic means, 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, iy )), in the linear regression calculations. Table 1 

follows:

Table 1 of §1066.220–

Dynamometer measurement systems that require linearity verifications

Measurement 

system Quantity Linearity criteria

| ymin(a1-1)+a0 | a1 SEE r

2

Speed v <0.05 % ∙ max v0.98-1.02 <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 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 
Page 830 of 903

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. 

(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.
Page 831 of 903

(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.

(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:
Page 832 of 903

roll

act

f d

v

n

 



Eq. 1066.235-1

Where:

f = frequency of the dynamometer speed sensing device, accurate to at least four 

significant figures.

droll = nominal roll diameter, accurate to the nearest 1.0 mm, consistent with 

§1066.225(d).

n = the number of pulses per revolution from the dynamometer roll speed sensor.

Example:

f = 2.9231 Hz = 2.9231 s-1

droll = 904.40 mm = 0.90440 m

n = 1 pulse/rev

act

2.9231 0.90440

1

v

 



vact = 8.3053 m/s

(ii) Repeat the steps in paragraph (c)(1)(i) of this section for the maximum speed 

expected during testing and at least two additional evenly spaced speed points between 

the starting speed and the maximum speed point.

(iii) Compare the calculated roll speed, vact, to each corresponding speed set point, vref, to 

determine values for speed error at each set point, verror, using the following equation:

verror = vact - vref

Eq. 1066.235-2

Example:

vact = 8.3053 m/s

vref = 8.3000 m/s

verror = 8.3053 – 8.3000 = 0.0053 m/s

(2) Frequency method. Install a piece of tape in the shape of an arrowhead on the surface 

of the dynamometer roll near the outer edge. Put a reference mark on the deck plate in 

line with the tape. Install a stroboscope or photo tachometer on the deck plate and direct 

the flash toward the tape on the roll. The stroboscope or photo tachometer must be 

calibrated according to the instrument manufacturer’s instructions and be capable of 

measuring with enough accuracy to perform the procedure as specified in this paragraph 

(c)(2). Determine the speed error as follows:

(i) Set the dynamometer to speed control mode. Set the dynamometer speed to a speed 

value of approximately 4.5 m/s (10 mph). Tune the stroboscope or photo tachometer 

until the signal matches the dynamometer roll speed. Record the frequency. Determine 

the roll speed, yact, using Eq. 1066.235-1, using the stroboscope or photo tachometer’s 

frequency for f.

(ii) Repeat the steps in paragraph (c)(2)(i) of this section for the maximum speed 

expected during testing and at least two additional evenly spaced speed points between 

the starting speed and the maximum speed point.
Page 833 of 903

(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 roadload coefficients representing vehicles of the appropriate weight. Determine the 

dynamometer’s settling response time, ts, based on the point at which there are no 

measured results more than 10 % above or below the final equilibrium value, as 

illustrated in Figure 1 of this section. The observed settling response time must be less 

than 100 milliseconds for each inertia setting. 

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:
Page 834 of 903

(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.

(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

(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:
Page 835 of 903

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.

(a) Overview. Verify the dynamometer’s parasitic loss as described in this section, and 

correct as necessary. This procedure determines the dynamometer’s internal losses that it 

must overcome to simulate road load. Characterize these losses in a parasitic loss curve 

that the dynamometer uses to apply compensating forces to maintain the desired roadload force at the roll surface.

(b) Scope and frequency. Perform this verification upon initial installation, after major 

maintenance, and upon failure of a verification in either §1066.270 or §1066.280. 

(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 
Page 836 of 903

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.

(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
Page 837 of 903

vfinal = 10.0 mph = 14.7 ft/s

 

2 2

error

62.16 13.5 14.7

2 60.00

FC   



FCerror = –16.5 ft∙lbf/s = –0.031 hp

(5) The friction compensation error may not exceed ±0.15 hp for dynamometers capable 

of testing vehicles at or below 20,000 pounds GVWR, or ±0.6 hp for dynamometers not 

capable of testing vehicles at or below 20,000 pounds GVWR. 

§1066.265 Acceleration and deceleration verification.

(a) Overview. This section describes how to verify the dynamometer’s ability to achieve 

targeted acceleration and deceleration rates. Paragraph (c) of this section describes how 

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.

(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:
Page 838 of 903

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.

(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:
Page 839 of 903

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

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 

road-load coefficients as required for each test, using good engineering judgment to 

ensure that these values properly represent in-use operation. Use the following procedure 

if your dynamometer does not perform this verification with an automated process:

(1) Warm up the dynamometer as specified by the dynamometer manufacturer.

(2) With the dynamometer in coastdown mode, set the dynamometer inertia for the 

smallest vehicle weight that you expect to test and set A, B, and C road-load coefficients 

to values typical of those used during testing. Program the dynamometer to coast down 

over the dynamometer operational speed range (typically from a speed of 80 mph through 
Page 840 of 903

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

(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 %
Page 841 of 903

(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.

(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 
Page 842 of 903

dynamometer before continuing with emission testing. Diagnosis should include 

performing the verifications in §1066.255 and §1066.260.

§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.

(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:
Page 843 of 903

(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.

(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 
Page 844 of 903

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

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.
Page 845 of 903

adj

B

98.21

293

T

D D

p

   

          

Eq. 1066.310-4

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.

(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:
Page 846 of 903

(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.

(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:
Page 847 of 903

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.

(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 four-wheel drive includes other multiple drive axle configurations.) This may

involve testing four-wheel 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.
Page 848 of 903

This section describes how to test a conventionally configured vehicle (vehicles with 

transmission shifters, foot pedal accelerators, etc). You may ask us to modify these 

procedures for vehicles that do not have these control features. 

(a) Start the vehicle as follows:

(1) At the beginning of the test cycle, start the vehicle according to the procedure 

described in the owners manual. In the case of 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 hotstart test without repeating the cold-start test, as long as you bring the vehicle to a hotstart 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 849 of 903

(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.

(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 
Page 850 of 903

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.

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

FTP1and LA-92 50

HFET 50

SC03 100 ± 5

US06 50

1

FTP humidity requirement does not apply for cold (-7°C), 

intermediate (10 °C), and hot (35 °C) temperature testing.

(e) You may perform a final calibration of proportional-flow control systems, which may

include performing practice runs.

(f) You may perform the following procedure to precondition sampling systems:

(1) Operate the vehicle over the test cycle.

(2) Operate any dilution systems at their expected flow rates. Prevent aqueous 

condensation in the dilution systems as described in 40 CFR 1065.140(c)(6), taking into 

account allowances given in §1066.110(b)(2)(iv). 

(3) Operate any PM sampling systems at their expected flow rates.

(4) Sample PM using any sample media. You may change sample media during 

preconditioning. You must discard preconditioning samples without weighing them.

(5) You may purge any gaseous sampling systems during preconditioning.

(6) You may conduct calibrations or verifications on any idle equipment or analyzers 

during preconditioning.

(g) Take the following steps before emission sampling begins:

(1) For batch sampling, connect clean storage media, such as evacuated bags or tareweighed filters.

(2) Start all measurement instruments according to the instrument manufacturer’s 

instructions and using good engineering judgment.

(3) Start dilution systems, sample pumps, and the data-collection system.

(4) Pre-heat or pre-cool heat exchangers in the sampling system to within their operating 

temperature tolerances for a test.
Page 851 of 903

(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.

(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 
Page 852 of 903

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.

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 853 of 903

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 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:

1.0 s

Time

S

p

e

e

d

Allowable 

Range

2.0 mph

2.0 mph

1.0 s
Page 854 of 903

(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. 

(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).

(j) For vehicles at or below 14,000 pounds GVWR, determine overall driver accuracy as 

follows:
Page 855 of 903

(1) Compare the following drive cycle metrics, based on measured vehicle speeds, to a 

reference value based on the target cycle that would have been generated by driving 

exactly to the target trace as described in SAE J2951 (incorporated by reference in 

§1066.1010).

(i) Determine the Energy Economy Rating as described in Section 5.4 of SAE J2951. 

(ii) Determine the Absolute Speed Change Rating as described in Section 6.1.2 of SAE 

J2951.

(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.

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.

Dj

D = the incremental target distance over an interval j, as described by Equation 13 of 

SAE J2951.

(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.

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 
Page 856 of 903

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.

(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.
Page 857 of 903

(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 

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 m3(from paragraph (f) of this section) 

ρNOx = 1913 g/m3

xNOx = 0.9721 ppm

c = 10-6

6

NOx m 170.878 1913 0.9721 10 0.3177 g 

    

(e) 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

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)
Page 858 of 903

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).

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 859 of 903

       

 

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 m3

Vct-PMstd = 0.925 m3

Vct-sdastd = 0.529 m3

Vcs-PMstd = 1.968 m3

Vcs-sdastd = 1.123 m3

Vht-PMstd = 1.122 m3

Vht-sdastd = 0.641 m3

Vhs-PMstd = 1.967 m3

Vhs-sdastd = 1.121 m3

mPMfil = 0.0000229 g

mPMbkgnd = 0.0000014 g

       

PM  

972.121 0.0000229 0.0000014

0.925 0.529 1.968 1.123 1.122 0.641 1.967 1.121

0.43 0.57

m

   

  

     



 

mPM = 0.00155 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
Page 860 of 903

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 m3

pin = 101.7 kPa

Tstd = 293.15 K

pstd = 101.325 kPa

Tin = 340.5 K

3

PMstd

1.071 101.7 293.15 0.925 m

101.325 340.5

V

 

 



(2) The following example provides a determination of Vmix based on CVS total flow and 

the removal of sample flow from one dilute exhaust gas analyzer and one PM sampling 

system that is utilizing secondary dilution. Note that your Vmix determination may vary

from Eq. 1066.610-6 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

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
Page 861 of 903

Vmix = 170.451 + 0.028 + 0.925 – 0.527 = 170.878 m3

(g) Total sample volume over a test interval. Calculate total flow, V[flow], for a CVS or 

exhaust gas sampler as follows: 

(1) Varying versus constant flow rates. The calculation methods depend on differentiating 

varying and constant flow, as follows:

(i) We consider the following to be examples of varying flows that require a continuous 

multiplication of concentration times volumetric flow rate: raw exhaust, exhaust diluted 

with a constant flow rate of dilution air, and CVS dilution with a CVS flow meter that 

does not have an upstream heat exchanger or electronic flow control.

(ii) We consider the following to be examples of constant exhaust flows: CVS diluted 

exhaust with a CVS flow meter that has an upstream heat exchanger, an electronic flow 

control, or both.

(2) Continuous sampling. For continuous sampling, you must frequently record a 

continuously updated flow signal. This recording requirement applies for both varying 

and constant flow rates.

(i) Varying flow rate. If you continuously sample from a varying exhaust flow rate, 

calculate V[flow] using the following equation:

[flow] i

i 1

N

V Q t



    

Eq. 1066.610-7

Where:

∆t = 1/frecord Eq. 1066.610-8

Example:

N = 505

QCVS1

 = 0.276 m3

/s

QCVS2

 = 0.294 m3

/s

frecord = 1 Hz

Using Eq. 1066.610-8,

t = 1/1 = 1 s

CVS CVS505 V Q   (0.276 0.294   ... ) 1



VCVS = 170.721 m3

(ii) Constant flow rate. If you continuously sample from a constant exhaust flow rate, use 

the same calculation described in paragraph (g)(2)(i) of this section or calculate the mean 

flow recorded over the test interval and treat the mean as a batch sample, as described in 

paragraph (g)(3)(ii) of this section. 

(3) Batch sampling. For batch sampling, calculate total flow by integrating a varying flow 

rate or by determining the mean of a constant flow rate, as follows:

(i) Varying flow rate. If you proportionally collect a batch sample from a varying 

exhaust flow rate, integrate the flow rate over the test interval to determine the total flow 

from which you extracted the proportional sample, as described in paragraph (g)(2)(i) of 

this section. 

(ii) Constant flow rate. If you batch sample from a constant exhaust flow rate, extract a 
Page 862 of 903

sample at a proportional or constant flow rate and calculate V[flow] from the flow from 

which you extract the sample by multiplying the mean flow rate by the time of the test 

interval using the following equation: 

V Q [flow]  t



Eq. 1066.610-9

Example:

QCVS

 = 0.338 m3

/s

t = 505 s 

CVS V   0.338 505

VCVS = 170.69 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:

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.

CO2 NMHC CH4 CO

1

1 3.76 1 ( )

2 4 2

DF

x x x x

  



   

                
Page 863 of 903

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:

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 m3

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.
Page 864 of 903

DF = dilution factor over the test interval.

Example:

N = 3

DF1 = 14.40

t1 = 505 s

DF2 = 24.48

t2 = 867 s

DF3 = 17.28

t3 = 505 s

w

505 867 505 18.82

111 505 867 505

14.40 24.48 17.28

DF         

                

§1066.630 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.

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, 
Page 865 of 903

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

 

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.

in p = mean static absolute pressure at the PDP inlet.

Tstd = standard temperature = 293.15 K.
Page 866 of 903

Example:

Qref

 = 0.1651 m

3

/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.

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
Page 867 of 903

20.9 0.809 0.028

23.4 0.788 -0.061

(6) For each speed at which you operate the PDP, use the appropriate regression equation 

from this paragraph (a) to calculate flow rate during emission testing as described in 

§1066.652.

(b) SSV calibration. The equations governing SSV flow assume one-dimensional 

isentropic inviscid flow of an ideal gas, except that the equations can account for 

compressible flow. Paragraph (b)(2)(iv) of this section describes other assumptions that 

may apply. If good engineering judgment dictates that you account for gas 

compressibility, you may either use an appropriate equation of state to determine values 

of Z as a function of measured pressure and temperature, or you may develop your own 

calibration equations based on good engineering judgment. Note that the equation for the 

flow coefficient, Cf, is based on the ideal gas assumption that the isentropic exponent, , 

is equal to the ratio of specific heats, Cp/Cv. If good engineering judgment dictates using 

a real gas isentropic exponent, you may either use an appropriate equation of state to 

determine values of  as a function of measured pressure and temperature, or you may

develop your own calibration equations based on good engineering judgment.

(1) Calculate volumetric flow rate, Q, as follows:

t in std

d f

std mix in

A R p T Q C C

p Z M R T

  

  

   



Eq. 1066.650-3

Where:

Cd = discharge coefficient, as determined in paragraph (b)(2)(i) of this section.

Cf = flow coefficient, as determined in paragraph (b)(2)(ii) of this section.

At = cross-sectional area at the venturi throat.

R = molar gas constant.

pin = static absolute pressure at the venturi inlet.

Tstd = standard temperature.

pstd = standard pressure.

Z = compressibility factor.

Mmix = molar mass of gas mixture.

Tin = absolute temperature at the venturi inlet.

(2) Perform the following steps to calibrate an SSV flow meter:

(i) Using the data collected in §1066.140, calculate Cd for each flow rate using the 

following equation:

std mix in

d ref

f t in std

p Z M R T

C Q

C A R p T

   

 

   



Eq. 1066.650-4

Where: 

Qref

 = measured volumetric flow rate from the reference flow meter.

(ii) Use the following equation to calculate Cf for each flow rate:
Page 868 of 903

 

   

1

2

1

2

f

4

2 1

1

r

C

r









 





 

  

 



  

 

Eq. 1066.650-5

Where:

 = isentropic exponent. For an ideal gas, this is the ratio of specific heats of the gas 

mixture, Cp/Cv.

r = pressure ratio, as determined in paragraph (b)(2)(iii) of this section.

 = ratio of venturi throat diameter to inlet diameter.

(iii) Calculate r using the following equation:

in

1

p

r

p



 

Eq. 1066.650-6

Where:

p = differential static pressure, calculated as venturi inlet pressure minus venturi throat 

pressure.

(iv) You may apply any of the following simplifying assumptions or develop other values 

as appropriate for your test configuration, consistent with good engineering judgment:

(A) For raw exhaust, diluted exhaust, and dilution air, you may assume that the gas 

mixture is incompressible and therefore behaves as an ideal gas (Z=1).

(B) For raw exhaust, you may assume =1.385.

(C) For diluted exhaust and dilution air, you may assume =1.399.

(D) For diluted exhaust and dilution air, you may assume Mmix is a function only of the 

amount of water in the dilution air or calibration air, xH2O, as follows:

  mix 2 M Mair 1 H2O H O H2O     x M  x

Eq. 1066.650-7

Where:

Mair = 28.964 g/mol

xH2O = amount of H2O in the dilution air, determined as described in 40 CFR 1065.645.

MH20 = 18.015 g/mol

Example:

xH2O = 0.0169 mol/mol

Mmix   28.964 1 0   .0169 18.0150.0169

Mmix = 28.7789 g/mol

(E) For diluted exhaust and dilution air, you may assume a constant molar mass of the 

mixture, Mmix, for all calibration and all testing if you control the amount of water in 

calibration air and in dilution air, as shown in the following table:

Table 2 of §1066.650–

Examples of dilution air and calibration air

dewpoints at which you may assume a constant Mmix.
Page 869 of 903

If calibration 

Tdew (C) is...

assume the following 

constant Mmix

(g/mol)...

for the following ranges of 

Tdew (C) during emission 

testsa

< 0 28.96559 < 18

0 28.89263 < 21

5 28.86148 < 22

10 28.81911 < 24

15 28.76224 < 26

20 28.68685 -8 to 28

25 28.58806 12 to 31

30 28.46005 23 to 34

aThe specified ranges are valid for all calibration and emission testing 

over the atmospheric pressure range (80.000 to 103.325) kPa.

(v) The following example illustrates the use of the governing equations to calculate Cd

of an SSV flow meter at one reference flow meter value:

Example:

Qref

 = 2.395 m3

/s

Z = 1

Mmix = 28.7789 g/mol = 0.0287789 kg/mol

R = 8.314472 J/(mol∙K) = 8.314472 (m2∙kg)/(s2∙mol∙K)

Tin = 298.15 K

At = 0.01824 m2

pin = 99.132 kPa = 99132 Pa = 99132 kg/(m∙s2)

 = 1.399

 = 0.8

p = 2.312 kPa

2.312 1 0.977

99.132

r   

 

   

1.399 1

1.399

2

1.399

1

2

f

4

2 1.399 0.977 1

1.399 1 0.8 0.977

C





    

  

  

 

Cf = 0.274

d

101.325 1 0.0287789 8.314472 298.15 2.395

0.274 0.01824 8.314472 99132 293.15

C

   

 

   

Cd = 1.695

(vi) Calculate the Reynolds number, Re#, for each reference volumetric flow rate, Qref



, 

using the throat diameter of the venturi, dt, and the uncorrected air density, . Because 

the dynamic viscosity, , is needed to compute Re#, you may use your own fluid 
Page 870 of 903

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#:

# ref

t

4 Q

Re =

d



 

 

 



Eq. 1066.650-8

Where, using the Sutherland three-coefficient viscosity model:

3

2

in 0

0

0 in

T T S

T T S

 

    

           

Eq. 1066.650-9

Where:

0 = Sutherland reference viscosity.

T0 = Sutherland reference temperature.

S = Sutherland constant.

Table 3 of §1065.640–

Sutherland three-coefficient viscosity model parameters

Gasa 0

T0 S

Temp 

range 

within ±2 

% errorb

Pressure 

limitb

kg /(m∙s) K K K kPa

Air 1.716∙10-5273 111 170 to 

1900 ≤ 1800

CO2 1.370∙10-5273 222 190 to 

1700 ≤ 3600

H2O 1.12∙10-5350 1064 360 to 

1500 ≤ 10000 

O2 1.919∙10-5273 139 190 to 

2000 ≤ 2500

N2 1.663∙10-5273 107 100 to 

1500 ≤ 1600

aUse tabulated parameters only for the pure gases, as listed. 

Do not combine parameters in calculations to calculate 

viscosities of gas mixtures.

b

The model results are valid only for ambient conditions in 

the specified ranges.

Example:

0 = 1.716∙10-5kg/(m∙s)

T0 = 273 K
Page 871 of 903

S = 111 K

3

2

5 298.15 273 111 1.716 10

273. 298.15 111



     

            

 = 1.838∙10-5kg/(m∙s)

Tin = 298.15 K

dt = 152.4 mm = 0.1524 m

 = 1.1508 kg/m3

#

5

4 1.1508 2.395

3.14159 0.1524 1.838 10

Re = 

 

  

Re#= 1.2531∙106

(vii) Calculate ρ using the following equation:

in mix

in

p MW

R T









Eq. 1066.650-10

Example:

99132 0.0287789

8.314472 298.15









ρ = 1.1508 kg/m3

(viii) Create an equation for Cd as a function of Re#, using paired values of the two 

quantitites. The equation may involve any mathematical expression, including a 

polynomial or a power series. The following equation is an example of a commonly used 

mathematical expression for relating Cd and Re#:

6

d 0 1 #

10 C a a

Re

  

Eq. 1066.650-11

(ix) Perform a least-squares regression analysis to determine the best-fit coefficients for 

the equation and calculate the equation’s regression statistics, SEE and r

2

, according to 

§1065.602.

(x) If the equation meets the criteria of SEE ≤ (0.5 % · refmax n) and r

2

≥ 0.995, you may

use the equation to determine Cd for emission tests, as described in §1065.642.

(xi) If the equation does not meet the specified statistical criteria, you may use good 

engineering judgment to omit calibration data points; however, you must use at least 

seven calibration data points to demonstrate that you meet the criteria. For example, this 

may involve narrowing the range of flow rates for a better curve fit.

(xii) Take corrective action if the equation does not meet the specified statistical criteria 

even after omitting calibration data points. For example, select another mathematical 

expression for the Cd versus Re#equation, check for leaks, or repeat the calibration 

process. If you must repeat the calibration process, we recommend applying tighter 

tolerances to measurements and allowing more time for flows to stabilize.

(xiii) Once you have an equation that meets the specified statistical criteria, you may use 

the equation only for the corresponding range of flow rates.

(c) CFV calibration. Some CFV flow meters consist of a single venturi and some consist 
Page 872 of 903

of multiple venturis, where different combinations of venturis are used to meter different 

flow rates. For CFV flow meters that consist of multiple venturis, either calibrate each 

venturi independently to determine a separate calibration coefficient, Kv, for each venturi, 

or calibrate each combination of venturis as one venturi by determining Kv for the 

system.

(1) To determine Kv for a single venturi or a combination of venturis, perform the 

following steps:

(i) Calculate an individual Kv for each calibration set point for each restrictor position 

using the following equation:

refstd in

v

in

Q T

K =

p





Eq. 1066.650-12

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 

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.
Page 873 of 903

(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.

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 m3/r
Page 874 of 903

0.06383 293.15 98.575 12.58

323.5 101.3

Q

 

 





Q&= 0.7079 m3/s

(b) SSV volumetric flow rate. Calculate SSV volumetric flow rate during an emission 

test, Q, as follows: 

t in std

d f

std mix in

A R p T Q C C

p Z M R T

  

  

   



Eq. 1066.652-3

Where:

Cd = discharge coefficient, as determined based on the Cd versus Re#equation in 

§1066.650(b)(2)(viii).

Cf = flow coefficient, as determined in §1066.650 (b)(2)(ii).

At = venturi throat cross-sectional area.

R = molar gas constant.

pin = static absolute pressure at the venturi inlet.

Tstd = standard temperature.

pstd = standard pressure.

Z = compressibility factor.

Mmix = molar mass of gas mixture.

Tin = absolute temperature at the venturi inlet.

Example: 

Cd = 0.890

Cf = 0.274

At = 0.01824 m2

R = 8.314472 J/(mol∙K) = 8.314472 (m2∙kg)/(s2∙mol∙K)

pin = 98.496 kPa

Tstd = 293.15 K

pstd = 101.325 kPa

Z = 1

Mmix = 28.7789 g/mol = 0.0287789 kg/mol

Tin = 296.85 K

0.01824 8.314472 98.496 293.15 0.89 0.274

101.325 1 0.0287789 8.314472 296.85

Q

  

  

   



Q

= 1.252 m3/s

(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.
Page 875 of 903

(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.

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 m3/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.

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.
Page 876 of 903

(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

 

     

   

  

 

  

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 
Page 877 of 903

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.

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 

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:
Page 878 of 903

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.

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.
Page 879 of 903

(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.

(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 carboncontaining 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 880 of 903

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).

(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 
Page 881 of 903

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 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 standardsetting 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 
Page 882 of 903

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 hotstabilized portion for the hot-start test is generally measured during the cold-start test; 

however, in certain cases, the hot-start test may involve a second full UDDS following 

the 10-minute soak, rather than repeating only the first 505 seconds. See §§1066.820 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 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 non-integrated 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 
Page 883 of 903

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 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:
Page 884 of 903

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.

(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 weight

basis

Equivalent test 

weight

Inertia weight 

class

Up to 1062 1000 1000

1063 to 1187 1125 1000

1188 to 1312 1250 1250

1313 to 1437 1375 1250

1438 to 1562 1500 1500

1563 to 1687 1625 1500

1688 to 1812 1750 1750

1813 to 1937 1875 1750

1938 to 2062 2000 2000

2063 to 2187 2125 2000

2188 to 2312 2250 2250

2313 to 2437 2375 2250
Page 885 of 903

2438 to 2562 2500 2500

2563 to 2687 2625 2500

2688 to 2812 2750 2750

2813 to 2937 2875 2750

2938 to 3062 3000 3000

3063 to 3187 3125 3000

3188 to 3312 3250 3000

3313 to 3437 3375 3500

3438 to 3562 3500 3500

3563 to 3687 3625 3500

3688 to 3812 3750 3500

3813 to 3937 3875 4000

3938 to 4125 4000 4000

4126 to 4375 4250 4000

4376 to 4625 4500 4500

4626 to 4875 4750 4500

4876 to 5125 5000 5000

5126 to 5375 5250 5000

5376 to 5750 5500 5500

5751 to 6250 6000 6000

6251 to 6750 6500 6500

6751 to 7250 7000 7000

7251 to 7750 7500 7500

7751 to 8250 8000 8000

8251 to 8750 8500 8500

8751 to 9250 9000 9000

9251 to 9750 9500 9500

9751 to 10250 10000 10000

10251 to 10750 10500 10500

10751 to 11250 11000 11000

11251 to 11750 11500 11500

11751 to 12250 12000 12000

12251 to 12750 12500 12500

12751 to 13250 13000 13000

13251 to 13750 13500 13500

13751 to 14000 14000 14000

(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) 
Page 886 of 903

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.

§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.
Page 887 of 903

(5) You may collect PM on a single filter over the cold-start UDDS and the full hot-start 

UDDS. If you use this method, adjust your sampling system flow rate to weight the filter 

face velocity based on weighting targets of 0.75 for the cold-start UDDS and 1.0 for the 

hot-start UDDS.

(c) Gaseous sampling options. Collect gaseous samples using any of the following 

procedures:

(1) You may collect a single sample for a full UDDS (cold-start or hot-start).

(2) You may sample emissions separately for transient and stabilized portions of any 

UDDS.

(3) You may omit the stabilized portion of the hot-start test (bag 4) and use the stabilized 

portion of the cold-start test (bag 2) in its place.

(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 888 of 903

§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

   

             

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:
Page 889 of 903

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. 

(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 
Page 890 of 903

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).

(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:

(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. 
Page 891 of 903

(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 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
Page 892 of 903

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

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.
Page 893 of 903

(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.

§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 period; ensure that the windows are adequately closed where instrumentation 

and wiring pass through to the interior.
Page 894 of 903

(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. 

§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 
Page 895 of 903

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 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:
Page 896 of 903

   

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.

(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 897 of 903

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 the mass emissions from multiple test intervals. For example, the standardsetting part may specify a complete duty cycle as a cold-start test interval and a hot-start 

test interval. In cases where multiple test intervals occur over a duty cycle, the standardsetting part may specify additional calculations that weight and combine results to arrive 

at composite values for comparison against the applicable standards.

Test weight has the meaning given in §1066.810.

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.
Page 898 of 903

We (us, our) means the Administrator of the Environmental Protection Agency

and any authorized representatives.

§1066.1005 Symbols, abbreviations, acronyms, and units of measure.

The procedures in this part generally follow either the International System of Units (SI) 

or the United States customary units, as detailed in NIST Special Publication 811, which 

we incorporate by reference in §1066.1010. See 40 CFR 1065.20 for specific provisions 

related to these conventions. This section summarizes the way we use symbols, units of 

measure, and other abbreviations.

(a) Symbols for quantities. This part uses the following symbols and units of measure for 

various quantities:

Symbol Quantity Unit Unit symbol Unit in terms of SI 

base units

α atomic hydrogen to carbon ratio mole per mole mol/mol 1

a acceleration feet per second squared or 

meters per second squared ft/s2

or m/s2 m∙s-2

β atomic oxygen to carbon ratio mole per mole mol/mol 1

c conversion factor

Cd discharge coefficient

d diameter meters m m

DF dilution factor 1

e mass weighted emission result grams/mile g/mi

F force pound force or newton lbf or N kg∙s-2

f frequency hertz Hz s

-1

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

Re# 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

Δt time interval, period, 1/frequency second s s

U voltage volt V m

2

∙kg∙s-3∙A-1

v speed miles per hour or meters per 

second mph or m/s m∙s-1

VP 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:

Symbol Species

CH4 methane

CO carbon monoxide
Page 899 of 903

CO2 carbon dioxide

NMHC nonmethane hydrocarbon

NMHCE nonmethane hydrocarbon equivalent

NMOG nonmethane organic gas

NO nitric oxide

NO2 nitrogen dioxide

NOx oxides of nitrogen

N2O nitrous oxide

O2 molecular oxygen

OHC oxygenated hydrocarbon

PM particulate matter

THC total hydrocarbon

THCE total hydrocarbon equivalent

(c) Superscripts. This part uses the following superscripts to define a quantity:

Superscript Quantity

overbar (such as y ) arithmetic mean

(d) Subscripts. This part uses the following subscripts to define a quantity:

Subscript Quantity

abs absolute quantity

act actual or measured condition

actint actual or measured condition over the speed interval

atmos atmospheric

b base

c coastdown

comp composite

cor corrected

dexh dilute exhaust quantity

dil dilute

e effective

emission emission specie

error error

exh raw exhaust quantity

exp expected quantity

fil filter

final final

flow flow measurement device type

i an individual of a series

int intake

init initial quantity, typically before an emission test

max

the maximum (i.e. peak) value expected at the standard over a test 

interval; not the maximum of an instrument range

meas measured quantity

ref reference quantity

rev revolution

roll dynamometer roll

s settling

sat saturated condition

span span quantity

std standard conditions

test test quantity

uncor uncorrected quantity

w weighted

zero zero quantity
Page 900 of 903

(e) Other acronyms and abbreviations. This part uses the following additional 

abbreviations and acronyms: 

A/C air conditioning

ALVW adjusted loaded vehicle weight

CFR Code of Federal Regulations

CFV critical-flow venturi

CVS constant-volume sampler

EPA Environmental Protection Agency

ETW equivalent test weight

EV electric vehicle

FID flame-ionization detector

FTP Federal test procedure

GC gas chromatograph

GHG greenhouse gas (including CO2, N2O, and CH4)

GVWR gross vehicle weight rating

HEV hybrid electric vehicle

HFET highway fuel economy test

HLDT heavy light-duty truck

HPLC high pressure liquid chromatography

IBR incorporated by reference

MDPV medium-duty passenger vehicle

NIST National Institute for Standards and Technology

PDP positive-displacement pump

PHEV plug-in hybrid electric vehicle

PM particulate matter

RESS 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

UDDS urban dynamometer driving cycle

US06 aggressive driving schedule

U.S.C. United States Code

(f) This part uses the following densities of chemical species:

Symbol Quantity1,2 g/m3g/ft3

ρCH4 density of methane 666.905 18.8847

ρCH3OH density of methanol 1332.02 37.7185

ρC2H5OH C1-equivalent density of ethanol 957.559 27.1151

ρC2H4O C1-equivalent density of acetaldehyde 915.658 25.9285

ρC3H8 density of propane 611.035 17.3026

ρC3H7OH C1-equivalent density of propanol 832.74 23.5806

ρCO density of carbon monoxide 1164.41 32.9725

ρCO2 density of carbon dioxide 1829.53 51.8064

ρHC-gas effective density of hydrocarbon - gaseous fuel3(see 3) (see 3)

ρHCHO density of formaldehyde 1248.21 35.3455

ρHC-liq effective density of hydrocarbon - liquid fuel4576.816 16.3336

ρNMHC-gas effective density of nonmethane hydrocarbon - gaseous fuel3(see 3) (see 3)

ρNMHC-liq effective density of nonmethane hydrocarbon - liquid fuel4576.816 16.3336

ρNMHCE-gas effective density of nonmethane equivalent hydrocarbon -

gaseous fuel3 (see 3) (see 3)

ρNMHCE-liq effective density of nonmethane equivalent hydrocarbon -

liquid fuel4 576.816 16.3336
Page 901 of 903

ρNOx effective density of oxides of nitrogen51912.5 54.156

ρN2O density of nitrous oxide 1829.66 51.8103

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-to-carbon 

ratio, , of 1.85.

5The effective density of NOx

is defined by the molar mass of nitrogen dioxide, NO2.

(g) Constants. (1) This part uses the following constants for the composition of dry air:

Symbol Quantity mol/mol 

xArair amount of argon in dry air 0.00934

xCO2air amount of carbon dioxide in dry air 0.000375

xN2air amount of nitrogen in dry air 0.78084

xO2air amount of oxygen in dry air 0.209445

(2) This part uses the following molar masses or effective molar masses of chemical 

species:

Symbol Quantity g/mol

(10-3·kg·mol-1)

Mair molar mass of dry air128.96559

MH2O molar mass of water 18.01528

1

See paragraph (g)(1) of this section for the composition of dry air.

(h) Prefixes. This part uses the following prefixes to define a quantity:

Symbol Quantity Value

 micro 10-6

m milli 10-3

c centi 10-2

k kilo 103

M mega 106

§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. 
Page 902 of 903

(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 903 of 903

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

Fuel Standards

Page 1002 of 1002

(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