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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 85, 86, 1036, 1037, 1039, 1042, 1048, 1054, 1065, 1066, 1068

DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Parts 523 and 535

[EPA-HQ-OAR-2012-0102; NHTSA-2012-0152]

RIN 2060-AR48; 2127-AL31

Heavy-Duty Engine and Vehicle, and Nonroad Technical Amendments

AGENCIES: Environmental Protection Agency (EPA) and National Highway Traffic 

Safety Administration (NHTSA), Department of Transportation.

ACTION: Direct final rule (EPA); Final rule (NHTSA).

SUMMARY: EPA and NHTSA, on behalf of the Department of Transportation, are 

each adopting corrections to provisions in our respective Medium- and Heavy-Duty 

Greenhouse Gas Emissions and Fuel Efficiency final rule issued on September 15, 2011

(76 FR 57106). These amendments eliminate duplicative reporting requirements, reduce 

inadvertent minor differences between the EPA and NHTSA programs regarding such 

matters as voluntary early model year compliance, better align testing procedures to 

market realities, and reduce unnecessary testing burdens. This action also separately 

amends several regulations exclusive to EPA by: (1) adjusting the provisions of the 

replacement engine exemption, (2) expanding EPA’s discretion to allow greater 

flexibility under the Transition Program for Equipment Manufacturers related to the Tier 

4 standards for nonroad diesel engines, (3) specifying multiple versions of the applicable 
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SAE standard for demonstrating that fuel lines for nonroad spark-ignition engines above 

19 kilowatts meet permeation requirements, and (4) allowing for the use of the ethanolbased test fuel specified by the California Air Resources Board for nonroad sparkignition engines at or below 19 kilowatts. Some of the individual EPA-only provisions of 

this action may have minor impacts on the costs and emission reductions of the 

underlying regulatory programs amended in this action, though in most cases these are 

simple technical amendments. For those provisions that may have a minor impact on the 

costs or benefits of the amended regulatory program, any potential impacts would be 

small and we have not attempted to quantify the potential changes. None of the 

provisions included in this rulemaking will increase the stringency of fuel efficiency or 

emission standards. 

DATES: These rules are effective on [insert date 60 days after publication in the 

FEDERAL REGISTER] without further notice, unless EPA or NHTSA receives 

adverse comment. If we receive relevant adverse comment on distinct elements of this 

rule by [insert date 30 days after publication in the FEDERAL REGISTER], we will 

publish a timely withdrawal in the Federal Register indicating which provisions we are 

withdrawing. The provisions that are not withdrawn will become effective on [insert 

date 60 days after publication in the FEDERAL REGISTER], notwithstanding 

adverse comment on any other provision.

The incorporation by reference of certain publications listed in this regulation is approved 

by the Director of the Federal Register as of [Insert date 60 days after publication in the

Federal Register].

Comment [A1]: 4/24/2013 – Suggest adding the 

caveat that it may change the costs and benefits of 

the rule. In particular, the engine replacement 

provisions will have associated costs and benefits 

although they have not been quantified.

4/26/2013 EPA RESPONSE: See edits in text.
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ADDRESSES: Submit your comments, identified by Docket ID No. NHTSA-2012-

0152 and/or EPA-HQ-OAR-2012-0102, by one of the following methods:

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

Email: a-and-r-docket@epa.gov

Fax: NHTSA: (202) 493-2251; EPA: (202) 566-9744

Mail: 

NHTSA: Docket Management Facility, M-30, U.S. Department of Transportation, West

Building, Ground Floor, Rm. W12-140, 1200 New Jersey Avenue, SE, Washington, DC 

20590.

EPA: Air and Radiation Docket and Information Center, Environmental Protection 

Agency, Air Docket, Mail-code 28221T, 1200 Pennsylvania Ave., NW, Washington, DC 

20460. 

1. Hand Delivery: 

NHTSA: West Building, Ground Floor, Rm. W12-140, 1200 New Jersey Avenue, SE, 

Washington, DC 20590, between 9 a.m. and 5 p.m. Eastern Time, Monday through 

Friday, except Federal Holidays.

2. EPA: EPA Docket Center (EPA/DC), EPA West, Room 3334, 1301 Constitution 

Ave., NW, Washington, DC, Attention Docket ID No. EPA-HQ- OAR-2012-0102. 

Such deliveries are only accepted during the Docket’s normal hours of operation, and 

special arrangements should be made for deliveries of boxed information.
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Instructions: Direct your comments to Docket ID No. NHTSA-2012-0152 and/or EPAHQ-OAR-2012-0102. See the SUPPLEMENTARY INFORMATION section on 

“Public Participation” for additional instructions on submitting written comments.

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., information 

claimed as Confidential Business Information (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 following 

locations:

NHTSA: Docket Management Facility, M-30, U.S. Department of Transportation, West 

Building, Ground Floor, Rm. W12-140, 1200 New Jersey Avenue, SE, Washington, DC 

20590. The Docket Management Facility is open between 9 a.m. and 5 p.m. Eastern 

Time, Monday through Friday, except Federal holidays.

EPA: EPA Docket 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: Lily Smith, Office of Chief Counsel, 

National Highway Traffic Safety Administration, 1200 New Jersey Avenue, SE, 

Washington, DC 20590; telephone: (202) 366-2992. Angela Cullen, Environmental 
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Protection Agency, Office of Transportation and Air Quality, Assessment and Standards 

Division, 2000 Traverwood Drive, Ann Arbor, Michigan 48105; telephone number: 734-

214-4419; email address: cullen.angela@epa.gov.

I. SUPPLEMENTARY INFORMATION

A. Why are EPA and NHTSA publishing a direct final rule?

The agencies have found that prior notice and comment is unnecessary for this 

action because it consists of minor amendments made for the following types of reasons: 

to eliminate duplicative reporting requirements, reduce inadvertent minor differences 

between the EPA and NHTSA programs regarding such matters as voluntary early model 

year compliance, better align testing procedures to market realities, reduce unnecessary 

testing burdens, and correct clear technical errors. As these amendments are not expected 

to be controversial or to result in adverse comment, the agencies believe that this action 

falls under the “good cause” exception to the Administrative Procedure Act requirement 

for prior notice and comment.1

If no adverse comments are received by within thirty days of publication, this rule

will become effective as stated in the DATES section. In that case, approximately 30 

days before the effective date, the agencies will publish a document in the Federal 

 

1

See 5 U.S.C. 553(b). The “good cause” exception provides that the requirement for prior notice and 

comment on a proposed action does not apply “when the agency for good cause finds (and incorporates the 

finding and a brief statement of reasons therefore in the rules issued) that notice and public procedure 

thereon are impracticable, unnecessary, or contrary to the public interest.”
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Register stating that no adverse comments were received and confirming that this rule

will become effective as scheduled. The agencies would not consider frivolous or 

irrelevant comments to be adverse. The agencies would also not consider a comment 

recommending additional actions or changes to be adverse, unless the comment also 

states why the final rule would be ineffective without the additional action or change.

If adverse comments are received to any part of this rule, that part will be 

withdrawn by publishing a timely notice in the Federal Register indicating which 

provisions are being withdrawn. The provisions that are not withdrawn will become 

effective on the date set out above, notwithstanding adverse comment on any other 

provision. 

If either or both agencies receive adverse comment to this rule, they will rely 

upon the agency-specific processes as follows, after the provision is withdrawn. If an 

adverse comment applies to a NHTSA provision of this rule, NHTSA will issue a notice 

of proposed rulemaking (NPRM) and provide another opportunity to comment. If EPA 

receives an adverse comment or a request for public hearing on a distinct EPA provision 

of this rulemaking, the related NPRM2published in the “Proposed Rules” section of 

today’s Federal Register will serve as the proposed rule to adopt the EPA provisions. If a 

public hearing is held on any provision that affects both agencies’ regulations, both 

 

2 This document contains EPA revisions for heavy-duty engines and vehicles and the EPA provisions for 

replacement engines.
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agencies will participate. EPA does not plan to institute a second comment period on 

this action. Any parties interested in commenting on EPA technical amendments must do 

so at this time. EPA would address all public comments in a subsequent final rule. 

We request that commenters identify in their comments any portions of the action 

with which they agree and support as written, in addition to any comments regarding 

provisions with which they disagree. In this way, the agencies will be able to adopt those 

elements of this action that are fully supported and most needed today while properly 

considering and addressing any adverse comments through a “notice and comment” 

rulemaking. For further information about commenting on this rule, see the 

ADDRESSES section of this document.

B. Does This Action Apply to Me?

This action affects companies that manufacture, sell, or import into the United 

States new heavy-duty engines and new Class 2b through 8 vehicles, including 

combination tractors, school and transit buses, vocational vehicles such as utility service 

trucks, as well as 3⁄4-ton and 1-ton pickup trucks and vans. The heavy-duty category 

incorporates all motor vehicles with a gross vehicle weight rating of 8,500 pounds or 

greater, and the engines that power them, except for medium-duty passenger vehicles 

already covered by the greenhouse gas emissions standards and corporate average fuel 

economy standards issued for light-duty model year 2012-2016 vehicles (75 FR at 25324, 

May 7, 2010). 

This action also affects nonroad engine manufacturers.

Regulated categories and entities include the following: 
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Category NAICS CodeaExamples of Potentially Affected 

Entities

Industry 336111 Motor Vehicle Manufacturers, Engine 

336112 and Truck Manufacturers

333618

336120

Industry 541514 Commercial Importers of Vehicles and 

811112 Vehicle Components

811198

Industry 336111 Alternative Fuel Vehicle Converters

336112

422720

454312

541514

541690

811198

336510

Industry 811310 Engine Repair, Remanufacture, and 

Maintenance

Note:

a

 North American Industry Classification System (NAICS)

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

regarding entities likely covered by these rules. This table lists the types of entities that 

the agencies are aware may be regulated by this action. Other types of entities not listed 

in the table could also be regulated. To determine whether your activities are regulated 

by this action, you should carefully examine the applicability criteria in the referenced 

regulations. You may direct questions regarding the applicability of this action to the 

persons listed in the preceding FOR FURTHER INFORMATION CONTACT section.

C. What Should I Consider as I Prepare My Comments?

Comments that are submitted for consideration by one agency should be 

identified as such, and comments that are submitted for consideration by both agencies 
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should be identified as such. Absent such identification, each agency will exercise its 

best judgment to determine whether a comment is submitted on its respective part of 

these rules. 

Further instructions for submitting comments to either the EPA or NHTSA docket 

are described below. 

NHTSA: Your comments must be written and in English. To ensure that your 

comments are correctly filed in the Docket, please include the Docket ID No. NHTSA2012-0152 in your comments. By regulation, your comments must not be more than 15 

pages long.3 NHTSA established this limit to encourage you to write your primary 

comments in a concise fashion. However, you may attach necessary additional 

documents to your comments. There is no limit on the length of the attachments. If you 

are submitting comments electronically as a PDF (Adobe) file, we ask that the documents 

submitted be scanned using the Optical Character Recognition (OCR) process, thus 

allowing the agencies to search and copy certain portions of your submissions.4 Please 

note that pursuant to the Data Quality Act, in order for the substantive data to be relied 

upon and used by the agencies, it must meet the information quality standards set forth in 

the Office of Management and Budget (OMB) and Department of Transportation (DOT) 

Data Quality Act guidelines. Accordingly, we encourage you to consult the guidelines in 

preparing your comments. OMB’s guidelines may be accessed at 

 

3

See 49 CFR § 553.21

4 Optical character recognition (OCR) is the process of converting an image of text, such as a scanned 

paper document or electronic fax file, into computer-editable text.
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http://www.whitehouse.gov/omb/fedreg/reproducible.html. DOT’s guidelines may be 

accessed at http://regs.dot.gov.

EPA: Direct your comments to Docket ID No. EPA-HQ-OAR-2012-0102. 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. 
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(1) Tips for Preparing Your Comments 

When submitting comments, remember to:

Identify the rulemaking by docket number and other identifying information (subject 

heading, Federal Register date and page number).

Follow directions - The agencies 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 in the 

DATES section above.
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(2) How Can I Be Sure That My Comments Were Received?

NHTSA: If you submit your comments by mail and wish Docket Management to notify 

you upon its receipt of your comments, enclose a self-addressed, stamped postcard in the 

envelope containing your comments. Upon receiving your comments, Docket 

Management will return the postcard by mail.

(3) How Do I Submit Confidential Business Information?

Any confidential business information (CBI) submitted to one of the agencies will 

also be available to the other agency.5 However, as with all public comments, any CBI 

only needs to be submitted to either one of the agencies’ dockets and it will be available 

to the other. Following are specific instructions for submitting CBI to either agency.

NHTSA: If you wish to submit any information under a claim of confidentiality, you 

should submit three copies of your complete submission, including the information you 

claim to be CBI, to the Chief Counsel, NHTSA, at the address given above under FOR 

FURTHER INFORMATION CONTACT, according the process outlined in 49 CFR 

part 512. When you send a comment containing CBI, you should include a cover letter 

setting forth the information specified in our CBI regulation. In addition, you should 

submit a copy from which you have deleted the claimed CBI to the Docket by one of the 

methods set forth above.

 

5

This statement constitutes notice to commenters pursuant to 40 CFR 2.209(c) that EPA will share 

confidential business information received with NHTSA unless commenters expressly specify that they 

wish to submit their CBI only to EPA and not to both agencies.
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EPA: Do not submit CBI to EPA through www.regulations.gov or e-mail. Clearly mark 

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

(4) Will the Agencies Consider Late Comments?

NHTSA and EPA will consider all comments received before the close of 

business on the comment closing date indicated above under DATES. To the extent 

practicable, we will also consider comments received after that date. If interested persons 

believe that any new information the agency places in the docket affects their comments, 

they may submit comments after the closing date concerning how the agency should 

consider that information for the final rules. However, the agencies’ ability to consider 

any such late comments in this rulemaking will be limited due to the time frame for 

issuing the final rules.

If a comment is received too late for us to practicably consider in developing the

final rules, we will consider that comment as an informal suggestion for future 

rulemaking action.
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(5) How Can I Read the Comments Submitted by Other People?

You may read the materials placed in the dockets for this document (e.g., the 

comments submitted in response to this document by other interested persons) at any 

time by going to http://www.regulations.gov. Follow the online instructions for accessing 

the dockets. You may also read the materials at the NHTSA Docket Management Facility 

or the EPA Docket Center by going to the street addresses given above under 

ADDRESSES.

II. Technical Amendments to the Heavy-Duty Engine and Vehicle Greenhouse Gas 

and Fuel Efficiency Standards Rules

EPA and NHTSA developed the first-ever program to reduce greenhouse gas 

(GHG) emissions and fuel consumption in the heavy-duty (HD) highway vehicle sector. 

The rulemaking was developed as a single, national program with both EPA and NHTSA 

promulgating complementary standards that allow manufacturers to build one set of 

vehicles to comply with both agencies’ regulations. This broad heavy-duty sector –

ranging from large pickups to sleeper-cab tractors – together represent the second largest 

contributor to oil consumption and GHG emissions from the mobile source sector, after 

light-duty passenger cars and trucks. The final rule was published in the Federal Register 

on September 15, 2011 (76 FR 57106). 

A. Background of the HD GHG and Fuel Efficiency Standards and Amendments

EPA’s GHG standards and NHTSA’s fuel consumption standards apply to 

manufacturers of the following types of heavy-duty vehicles and their engines:
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Heavy-duty Pickup Trucks and Vans

Combination Tractors

Vocational Vehicles

The rules include separate standards for the engines that power combination 

tractors and vocational vehicles. Certain parts of the program are exclusive to EPA’s

GHG standards. These include EPA’s final hydrofluorocarbon standards to control 

leakage from air conditioning systems in combination tractors and in pickup trucks and 

vans. Also exclusive to the EPA rules are standards for nitrous oxide (N2O) and methane 

(CH4) emissions standards that apply to all heavy-duty engines and to pickup trucks and

vans.

EPA’s final greenhouse gas emission standards for heavy-duty vehicles under the 

Clean Air Act will begin with model year 2014. NHTSA’s final fuel consumption 

standards under the Energy Independence and Security Act of 2007 will be voluntary in 

model years 2014 and 2015, becoming mandatory with model year 2016 for most 

regulatory categories. Both agencies allow manufacturers to comply early in model year 

2013 and promote early compliance by providing incentives to do so. 

In the final rulemaking, EPA established all-new regulations in 40 CFR parts 

1036, 1037, and 1066. EPA also included changes to existing regulations in 40 CFR 

parts 85, 86, 1039, 1065, and 1068. Similarly, NHTSA modified its existing regulations 

in 49 CFR parts 523 and 534, and established an all-new regulation in 49 CFR part 535. 

After publication of the heavy-duty rule, EPA and NHTSA began an extensive 

outreach effort to aid in the rule’s implementation. EPA and NHTSA held public 
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workshops on November 3, 2011 and August 10, 2012. In the course of these efforts, the 

agencies received a series of comments on specific aspects of the rules and prepared 

question and answer responses.6 In some cases, it became clear that minor changes to the 

rules would better clarify the rule’s intent, or amend the rule to make it more effective. 

The amendments adopted in this rule are largely based on these implementation 

discussions. 

The revisions related to the heavy-duty GHG emissions and fuel efficiency 

regulations in this final rule generally affect the joint heavy-duty program. Therefore, the 

agencies are issuing this joint rule to maintain a single, harmonized program. However, 

some of these technical amendments are unique to the rules of one or the other agency. 

Thus, this section is further divided into three subsections. First is the set of amendments 

that directly affect both EPA’s and NHTSA’s regulations, which are discussed in Section 

II.B below. Next, the technical amendments exclusive to NHTSA’s regulations in 49 

CFR parts 523 and 535 are discussed in Section II.C. Finally, EPA’s unique amendments 

in 40 CFR parts 86, 1036, 1037, 1065, and 1066, are discussed in Section II.D. 

B. Joint Heavy-Duty GHG and Fuel Efficiency Technical Amendments

The following amendments correct minor, technical inconsistencies and add 

clarifications in the current regulatory text of both agencies. If adverse comment is 

received by either agency relative to any aspect of the joint technical amendments that 

 

6

See U.S. EPA website at http://www.epa.gov/otaq/climate/regs-heavy-duty.htm.
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directly affect both EPA’s and NHTSA’s regulations, then both agencies will withdraw 

that joint amendment. A comparison of the original and amended regulatory text is 

provided in a memorandum to the dockets for this rulemaking.7

(1) Hybrid Testing

40 CFR 1036.525, 40 CFR 1036.615, and 49 CFR 535.7(e)(1)(ii) specify 

requirements for testing hybrid engines and engines with Rankine cycle waste heat 

recovery. The regulatory text includes references for testing “post-transmission” and 

“pre-transmission” hybrid systems in these sections. In a pre-transmission hybrid system, 

the energy from both the engine and motor is input into the drive shaft prior to the 

transmission. In a post-transmission hybrid system, the engine energy is input into the 

drive shaft prior to the transmission, but the motor energy is input into the drive shaft 

after the transmission. Since post-transmission hybrid systems are incompatible with 

engine testing, the agencies have decided to remove the reference to post-transmissions 

systems in the hybrid engine test requirements in 40 CFR part 1036 and 49 CFR part 

535. 40 CFR 1037.525, 40 CFR 1037.550, 40 CFR 1037.615, and 49 CFR 535.7(e)(1)(i) 

include requirements for testing post-transmission hybrids using a vehicle test. The 

agencies anticipate that there will be no impact on manufacturers by the deletion of this 

 

7 Hicks, M. and A. Cullen. Memorandum to Dockets EPA-HQ-OAR-2012-0102 and NHTSA2012-0152. Heavy-Duty Engine and Vehicle Greenhouse Gas Emissions and Fuel Consumption 

Regulatory Changes. March 2013.
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text, since the vehicle test procedures set out in the regulation specify how to test posttransmission systems.

Specifically, 40 CFR 1037.525, 40 CFR 1037.550, 40 CFR 1037.615, and 49 

CFR 535.7(e)(1)(i) describe or reference the procedure to be used for testing hybrid 

systems with and without power take-off (PTO) devices on a vehicle test. Both pre- and 

post-transmission hybrid systems can use, and be tested with and without, PTO devices

on a whole vehicle test. The current rule text states that manufacturers can test posttransmission hybrid systems on a whole vehicle test procedure to quantify CO2 and fuel 

consumption improvements resulting with and without PTO equipment, but inadvertently 

excludes pre-transmission hybrid systems. Therefore, agencies are amending the 

language to allow these pre-transmission hybrid systems with and without PTO to be 

tested on the vehicle test procedures in 40 CFR 1037.525, 40 CFR 1037.550, and 49 CFR 

535.7(e)(1)(i). The agencies believe this is a non-controversial amendment that will 

allow the existing vehicle test procedure to appropriately apply to existing hybrid

systems.

(2) Advanced Technology Improvement Factor

40 CFR 1037.615 and 49 CFR 535.7(e)(1)(i) describe the procedure for 

measuring CO2 and fuel consumption improvements from vehicles with hybrid and other

advanced technologies (such as Rankine engines, electric vehicles and fuel cell vehicles), 
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in order to generate advanced technology credits.840 CFR 1037.615 specifies how 

manufacturers can measure the effectiveness of the advanced system by chassis-testing a 

vehicle equipped with the advanced system and an equivalent conventional vehicle using 

the test procedures in 40 CFR part 1037, subpart F. 

The effectiveness of the advanced system is calculated by measuring the CO2

output from chassis tests of the vehicle with the advanced system and an equivalent 

conventional vehicle, thereby obtaining the relative marginal improvement between the 

two vehicles (the “improvement factor”). The “benefit” associated with the advanced 

system is then calculated by multiplying the Greenhouse Gas Emissions Model (GEM) 

result for the vehicle with advanced technology by the dimensionless improvement 

factor. The benefit is then converted to advanced technology credits for the model year 

production volume of the vehicle subfamily with the advanced technology. 

The final rule specified the procedure for applying the improvement factor in 

simulating a chassis test with a post-transmission hybrid system for A to B testing (40 

CFR 1037.550) across multiple vehicle configurations having the same advanced 

technology. However, the regulations for developing the improvement factor using the 

chassis test procedures (40 CFR 1037.615 and 49 CFR 535.7(e)(1)(i)(A)(3)), did not 

allow the improvement factor to be applied to multiple vehicle configurations having the 

 

8 Advanced technology credits may be increased by a 1.5 multiplier and applied to any heavy-duty vehicle 

or engine subcategory with certain maximum limits applying. See 40 CFR 1036.740, 1037.740 and 49 

CFR 535.7(e) for description of advanced technology credit program. 
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same advanced technology . The agencies are, therefore, amending the regulatory text 

that describes the measurement of advanced technology improvement to include this 

optional specification as well (in effect, carrying over the specification from 40 CFR 

1037.550 to 40 CFR 1037.615 and 49 CFR 535.7(e)(1)(i)(A)(3)). The hybrid and 

advanced technology improvement factor can now be applied to multiple vehicle 

configurations using the same technology, as long as the value used for other 

configurations “represents the vehicle configuration with the smallest potential reduction 

in greenhouse gas emissions as a result of the hybrid capability” and is consistent with 

good engineering judgement. The agencies believe that no one will object to these 

changes.

The agencies are therefore revising 40 CFR 1037.615 and 49 CFR 535.7(e)(1)(i) 

to allow manufacturers, if they wish, to generate advanced technology credits from

multiple heavy-duty vehicle configurations within a vehicle family group by testing a 

single vehicle of that group, provided the vehicle tested has the smallest potential 

reduction in fuel consumption of the vehicles with advanced technology capability. The 

agencies anticipate that this change may reduce testing and reporting costs for 

manufacturers while still allowing flexibility in choosing to test additional configurations 

within the family group. By limiting the use of this testing option to vehicles with the 

smallest potential reduction in emissions (or fuel consumption), fuel efficiency gains and 

emission reductions will not be compromised. Therefore, the agencies do not expect this 

change to be controversial.
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(3) Optional Certification for Up to Class 6 Spark-Ignition Engine Vehicles

Heavy-duty pickup trucks and vans are pickup trucks and vans with a gross 

vehicle weight rating between 8,501 pounds and 14,000 pounds (Class 2b through 3 

vehicles) manufactured as complete vehicles by a single or final stage manufacturer or 

manufactured as incomplete vehicles as designated by a manufacturer. Under the GHG 

rules and fuel efficiency rules, these vehicles are certified on a chassis dynamometer test, 

as opposed to the GEM simulation tool used to certify the vocational and tractor 

categories. NHTSA’s current regulations allow Classes 4 and 5 spark-ignition vehicles 

the option of certifying on a chassis dynamometer test and to comply with heavy-duty 

pickup truck and van standards instead of vocational standards, as those vehicles may 

have more similar characteristics to Class 2b-3 pickups or vans than they do with other 

vocational vehicles in their class.9 At the time of the final rule, NHTSA was unaware of 

any higher class spark ignition vehicles that would be similarly appropriate to test on a 

chassis dynamometer. EPA’s current regulations allow spark-ignition vehicles of all 

classes the option of certifying on a chassis dynamometer test and to the standards in 40 

CFR 1037.104.

10

This amendment will align the regulatory texts by closing the current gap in 

vehicle classes eligible for NHTSA’s and EPA’s optional certification provisions. The 

 

9

See 49 CFR 523.7.

10 See 40 CFR 1037.150(l).
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agencies are aware of several Class 4 and 5 vehicles that could benefit from the optional 

certification path but now have identified one spark-ignition Class 6 vehicle for which the 

chassis dynamometer test would be appropriate. This vehicle is available in complete 

and cab-complete configurations. NHTSA has performed an analysis that supports that 

allowing this testing option up to and including Class 6 vehicles will reduce testing 

burden without resulting in a credit windfall or otherwise affecting the stringency of the 

standards.11 As the agencies are not aware of any spark-ignition vehicles above Class 6, 

we believe it is appropriate to limit this option to Classes 6 and below. Therefore, the 

agencies anticipate that this alignment will be non-controversial.

The agencies are therefore allowing manufacturers of complete or cab-complete 

vehicles up to and including Class 6 vehicles that have spark-ignition engines the option 

of certifying using the chassis dynamometer test procedures and to the standards of 40 

CFR 1037.104. The agencies are revising the requirements in 40 CFR 1037.104, 40 CFR 

1037.150, 49 CFR 523.7, and 49 CFR 535.5(a)(6) to reflect this alignment of provisions. 

(4) Reporting for Heavy-Duty Pickup Truck and Van Manufacturers

For model years 2013 and later, heavy-duty pickup truck and van (PUV) (i.e., 

Class 2b-3) manufacturers complying with NHTSA's voluntary and mandatory standards 

are required to submit two different reports after the end of the model year (49 

CFR 535.8(d) and (e)). Manufacturers must submit an end-of-the-year-report (EOY 

 

11 NHTSA. Memorandum to Docket NHTSA-2012-0152. November 2012. 
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report), including both GHG emissions and fuel consumption information, within 90 days 

after the end of the given model year and no later than April 1 of the next calendar year. 

Manufacturers must also submit a final report within 270 days after the end of the given 

model year and no later than October 1 of the next calendar year. Both EOY and final 

reports contain the same information, and are used by the agencies to review a 

manufacturer’s final compliance data and to identify which manufacturers have a credit 

surplus or deficit for the given model year. Thus, NHTSA’s final rule regulatory text 

requires that both a final and an EOY report be submitted from all heavy-duty PUV 

manufacturers. EPA requires one final report from the heavy-duty PUV manufacturers, 

specified in 40 CFR 86.1865-12(l)(2). This final report must be submitted no later than 

May 1 of the calendar year following the given model year.

The final rule preamble discussed the agencies’ intent to streamline final reports 

submitted to the agencies, consolidating the multiple and separate reports as proposed in 

the NPRM (see 76 FR 57262). However, the agencies believed, and still believe that 

requiring two reports from manufacturers that have not previously been subject to fuel 

efficiency regulations will assist in assessing manufacturer compliance and will assist in 

the identification of any potential issues. That reasoning does not apply to PUV 

manufacturers, who are already regulated under the light-duty CAFE program and have 

well-established reporting systems. Further, for this joint national program, the agencies 

intended that PUV manufacturers would send single combined reports to satisfy the 

compliance needs of both agencies. The additional report presently required by the 

NHTSA regulation is inconsistent with this goal. 
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NHTSA is therefore combining the EOY and final reporting requirements for 

heavy-duty pickup truck and van manufacturers in 49 CFR 535.8(d) and (e). In parallel 

with the existing EPA regulations, those manufacturers will now only be required to 

submit a single final report. To supplement the existing reference to the provisions 

outlining this requirement, EPA and NHTSA are also adding another more specific 

reference in the regulations to clarify the alignment of the submission date for these 

reports with that of EOY reports from other heavy-duty vehicle and engine manufacturers

(90 days after the end of the given model year and no later than April 1 of the next 

calendar year). This amendment will harmonize reporting requirements between the two 

agencies and reduce the compliance burden for manufacturers, without affecting the 

overall content reported, or the agencies’ ability to effectively assess compliance. As 

such, the agencies do not expect that it will be controversial.

(5) Configuration and Subconfiguration Definitions

The existing EPA and NHTSA regulations contain definitions for “configuration” 

and “subconfiguration,” which define how to group vehicles by similar characteristics 

within a test group when conducting testing to determine CO2 emissions and fuel 

consumption rates for heavy-duty pickup trucks and vans. In each agency’s regulations, 

“configuration” means a subclassification within a test group that is based on engine 

code, transmission type and gear ratios, final drive ratio and other parameters that EPA

designates. Likewise, “subconfiguration” means a unique combination within a vehicle 

configuration of equivalent test weight, road-load horsepower, and any other operational 
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characteristics or parameters that EPA determines may significantly affect CO2 emissions 

within a vehicle configuration. 

The agencies believe the current definitions could be specified further according 

to established principles to prevent any ambiguity for manufacturers in conducting testing 

for heavy-duty pickup trucks and vans. The terms “transmission type” and “engine code” 

can be further defined in the definition for “configuration,” to reflect common industry 

understanding of the terms. In addition, the term “equivalent test weight” could be 

further defined in the definition for “subconfiguration” to carryover the existing 

definition included in 40 CFR 1037.104(d)(11). Therefore, the agencies are adding these 

further details to clarify these terms in 40 CFR 1037.104(d)(12) and 49 CFR 535.4. As 

both additions provide clarity to existing concepts, and do not introduce new meanings to 

the terms, the agencies believe they are non-controversial. 

(6) Vocational Tractor Vehicle Families

In the final rule, the regulatory text in 40 CFR 1037.230 related to vocational 

tractor families is unintentionally ambiguous, and is inconsistent with, the preamble and 

other regulatory text. In the vocational tractor provisions of 40 CFR 1037.630(b)(2), 

EPA requires that tractors “reclassified under this provision must be certified as a 

separate vehicle family. However, they remain part of the vocational regulatory 

subcategory and averaging set that applies to their weight class.” Although 40 CFR 

1037.630(b)(2) requires two vocational tractor families dependent on the GVWR of the 

vehicle, the text in 40 CFR 1037.230(a)(1) implies only a single vocational tractor family 

default. This inconsistency is the result of an oversight when provisions were added 
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allowing tractors to certify as vocational vehicles, and it is inconsistent with the way 

vehicle families are treated throughout the program, where they are split by weight class

(76 FR at 57240, September 15, 2011). Therefore, EPA is revising 40 CFR 

1037.230(a)(1) to be consistent with 40 CFR 1037.630(b)(2) by splitting the vocational 

vehicles families into two groups, those above 33,000 pounds GVWR and those above

26,000 pounds GVWR and at or below 33,000 pounds GVWR.

NHTSA is adding the same distinction in 49 CFR 535.5(c) to clarify how fuel 

consumption credits are generated and apply to averaging sets for these vehicles. As 

these clarifications align with the existing treatment of all vehicle families and the 

premise of the division of vehicle families, the agencies believe they are noncontroversial.

C. NHTSA Regulatory Action on HD Fuel Efficiency Technical Amendments

NHTSA seeks to correct technical errors, clarify requirements, and incorporate 

requirements that were inadvertently omitted in 49 CFR part 535 in order to align with 

EPA’s current regulatory text. As the following changes merely parallel existing EPA 

requirements that were more consistent with the intent of the final rule and will not result 

in additional requirements for manufacturers or in a change in the stringency of the 

standards, they are not anticipated to be controversial or to result in adverse comment. 
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A side-by-side comparison of the original and amended regulatory text is 

provided in a memorandum to the dockets for this rulemaking.12

(1) Secondary Manufacturers

Both fuel consumption and greenhouse gas emission standards apply to the 

manufacturer holding the EPA certificate of conformity. In the EPA regulatory text (40 

CFR 1037.620(a) and (b)), a primary manufacturer has the option to transfer an 

uncertified incomplete tractor or vocational vehicle to a secondary manufacturer to be 

completed and sold in the United States so long as that secondary manufacturer has

substantial control over the final design and completes assembly of the emission controls 

(ensuring that the engine and vehicle will conform to regulations in their final 

configurations). By agreement with the primary manufacturer, the secondary 

manufacturer may finish the assembly of the emission control systems of a partially 

complete vehicle and perform vehicle testing. In that case, the second stage manufacturer 

would apply for the vehicle’s EPA certificate of conformity. 

The current NHTSA regulations do not specify the process by which a secondary 

stage manufacturer may become an EPA certificate holder, and thus subject to both 

greenhouse gas emissions and fuel consumption standards. Thus, if someone unfamiliar 

with the EPA process were to read the NHTSA regulations alone, it would not be clear 

 

12 Hicks, M. and A. Cullen. Memorandum to Dockets EPA-HQ-OAR-2012-0102 and NHTSA2012-0152. Heavy-Duty Engine and Vehicle Greenhouse Gas Emissions and Fuel Consumption 

Regulatory Changes. March 2013.
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how a secondary stage manufacturer could become subject to fuel consumption 

standards. Therefore, NHTSA is modifying its provisions in 49 CFR 535.3(b) and (c) to 

more clearly include secondary stage manufacturers meeting the EPA requirements in 40 

CFR 1037.620 as subject to the fuel consumption standards. NHTSA is also modifying 

its provisions in 49 CFR 535.7(a) to clarify that either the primary or secondary 

manufacturer can generate fuel consumption credits for over-compliance and may use 

one or more of the program flexibilities in gaining credits.

These clarifications will align NHTSA’s regulations with EPA’s. As the 

clarifications simplify the path a reader must take to understand how an entity becomes 

subject to the fuel consumption standards, and do not actually change the application of 

the standards, NHTSA does not expect this to be controversial.

(2) Credit Holders

In the preamble to the final rule, the agencies stated that the NHTSA and EPA

flexibility provisions (“ABT” programs)13 are essentially identical in structure and 

function (see 76 FR 57127). The agencies also stated that they intended to allow a 

manufacturer to offset any credit shortfalls within an averaging set, by using ‘‘banked’’ 

or ‘‘traded’’ credits received from another manufacturer. The EPA regulations (40 CFR 

1036.701(e) and (h)) allow manufacturers to trade emissions credits generated from 

engines or vehicles to any purchaser other than manufacturers so long as those parties 

 

13 NHTSA and EPA flexibilities include: Averaging, banking, and trading (ABT) provisions; early credits; 

advanced technology credits (including hybrid powertrains); and innovative technology credit provisions.
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retire the credits. Likewise, trading is defined as “the exchange of emission credits 

between manufacturers, or the transfer of credits to another party to retire them” (40 CFR 

1036.720(a) and 1037.720(a)). The current NHTSA regulations are silent on how parties 

other than manufacturers can acquire and trade credits.

NHTSA believes that the existing EPA ABT provisions help to maximize the 

benefits of the standards achieved during this critical initial phase of the program by 

providing the means for manufacturers to take full advantage of the program flexibility to 

trade earned credits, while providing a path for this flexibility to result in continued gains 

in fuel efficiency. In addition, NHTSA did not envision differences between the EPA 

and NHTSA ABT programs. Therefore, NHTSA is adding requirements to 49 CFR part 

535 that parallel EPA’s treatment of non-manufacturers in the ABT program. NHTSA is 

adding a definition in 49 CFR 535.4 for “credit holder” and adding requirements in 49 

CFR 535.7 to clarify the limitations for non-manufacturers to obtain and trade fuel 

consumption credits. These additions will complement the EPA requirements in 40 CFR 

1036.701(h), 1036.720(a), 1037.701(e), and 1037.720(a), and we do not expect anyone to 

object to this provision.

(3) Voluntary Compliance

Manufacturers can voluntarily comply early with both the NHTSA and EPA 

standards for model year (MY) 2013, and with the NHTSA standards through MY 2015

(EPA’s standards are mandatory beginning in MY 2014). For MYs 2013 and 2014, EPA 

provides additional flexibilities and specifications in 40 CFR 1037.150 to incentivize 

early compliance. NHTSA inadvertently omitted parallel provisions for its early 
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compliance program. As described in the final rule preamble, manufacturers entering the 

early compliance program for NHTSA must do so “exactly as implemented” under 

EPA’s early compliance program (see 76 FR 57245). The purpose of the NHTSA early 

compliance provisions is to provide incentives for near-term fuel efficiency gains by 

allowing manufacturers to comply with both programs simultaneously in MYs 2013 and 

2014.

EPA provisions in 40 CFR 1037.150(a)(2) limit the number of EPA credits a 

manufacturer can generate for heavy-duty pickup trucks and vans produced after MY

2013 begins. EPA specifies that for any test groups used to certify these vehicles 

produced after the start of the model year, a manufacturer may only generate credits for 

those vehicles that are produced after the last test groups has received an approved 

certificate by EPA. Therefore, for example, if a manufacturer produces three test groups 

in an averaging set and it receives certificates for those test groups on January 4, 2013, 

March 15, 2013, and April 24, 2013, it may not generate credits for its MY 2013 

production for any of the vehicles that are produced before April 24, 2013. The same 

limitation is provided for production tractors and vocational vehicles (40 CFR 

1037.150(a)(1)). NHTSA is proposing to incorporate these provisions into its voluntary 

compliance sections (49 CFR 535.5(a)(4), (b)(2) and (c)(2)) in order to ensure 

harmonization between the two programs. Otherwise, manufacturers could gain credits 

under the NHTSA program that would be excluded by the EPA program.

For MY 2013, EPA provisions allow manufacturers to certify their U.S.-directed 

production tractors and vocational vehicles within each regulatory subcategory separately
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(instead of certifying all the vehicles within a regulatory category) as an incentive for 

early introduction (40 CFR 1037.150(a)(1)). For example, a manufacturer could certify

only its medium heavy-duty vocational vehicles in MY 2013 and then certify all of its 

three vocational vehicle subcategories starting in MY 2014. NHTSA provided parallel 

provisions in 49 CFR 535.5(b)(2) and (c)(2), but the current regulatory text would require 

manufacturers to comply with all the vehicles within each regulatory category. Thus, in 

this example, the vocational vehicle manufacturer would have to certify all of its U.S.-

directed production vehicles in MY 2013 for NHTSA whereas it would only have to 

certify its medium heavy-duty vocational vehicles for EPA. The mismatch in certified 

vehicles under the EPA and NHTSA programs for MY 2013 could cause manufacturers 

to opt to comply with the EPA standards early, but to not opt into the NHTSA program or 

could disadvantage a manufacturer under the NHTSA program compared to the EPA 

program. NHTSA is therefore correcting 49 CFR 535.5(b)(2) and (c)(2) to include the

same provisions for regulatory sub-category compliance for MY 2013 as EPA.

The definition of a model year in the final rule allows manufacturers to include 

vehicles in a given model year that are manufactured after January 1 of the previous 

calendar year for which the model year is named through December 31 of the 

corresponding year (see 40 CFR 1037.801 and 49 CFR 535.4). However, compliance 

with EPA standards for model year 2014 is optional for vehicles manufactured prior to 

January 1, 2014 (40 CFR 1037.150(g)). Thus, a manufacturer may choose to certify only 

vehicles produced from January 1, 2014 through December 31, 2014 and exclude model 

year 2014 vehicles produced between January 1, 2013 and December 31, 2013. 
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NHTSA’s requirements for the voluntary MY 2014 do not allow manufacturers this same 

flexibility. Instead, manufacturers choosing to comply with the NHTSA program in MY

2014 must certify vehicles produced over the entire standard model year period. NHTSA 

intended that provisions for voluntary early compliance with its program align with the 

EPA program. NHTSA believes that the MY 2014 EPA provisions are appropriate for 

that model year, the first mandatory year under the EPA program, particularly because 

they would lead to the least confusion among manufacturers. Aligning NHTSA’s 

program provisions with EPA’s will encourage manufactures to voluntarily opt in to the 

NHTSA program and enable manufacturers to generate similar credit balances in both 

programs, as intended. Therefore, NHTSA is modifying 49 CFR 535.5(a)(4), (b)(2) and 

(c)(2) to incorporate those provisions. As manufacturers typically lock their production 

plans anywhere from 18 to 24 months in advance of the production model year, they may 

not be able to bring early MY 2014 production vehicles into compliance with the NHTSA 

program absent this change.

As these corrections will align the NHTSA early compliance program to the 

specifications provided in the EPA program, and thus also align the NHTSA program 

with the intent of harmonization expressed in the preamble, NHTSA does not expect 

these corrections to be controversial.

(4) Reporting

The final rule preamble specifies that a manufacturer not participating in the ABT 

program is required to provide an end-of-the-year (EOY) report after each model year.

The EPA regulations (40 CFR 1036.250 and 1037.250) require this report to be submitted 
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within 90 days after the calendar year ends. The NHTSA regulations require two reports 

for non-ABT participating manufacturers, an EOY report containing preliminary final 

estimates and a final report containing the final data. For this joint national program, the 

agencies developed their reporting requirements with the intent for manufacturers to send 

single combined reports to satisfy the compliance requirements of both agencies. The 

differences in the agencies’ reporting requirements do not support this goal. Further, 

requiring non-ABT manufacturers to submit two reports would create unnecessary 

burden, as a single report would enable NHTSA to assess compliance for non-ABT 

manufacturers. Therefore, NHTSA is restructuring its reporting provisions (49 CFR 

535.8(d) and (e)) to align with EPA’s by clarifying that non-ABT participating 

manufacturers are only required to provide one report with final data 90 days after the 

model year. 

For vehicle and engine manufacturers participating in the ABT program, EPA 

and NHTSA require EOY reports to be submitted with preliminary final estimates of 

compliance information 90 days after the model year ends. NHTSA is adding a 

clarification in 49 CFR 535.8(d) to specify that these EOY reports for participating 

manufacturers must contain preliminary data and for non-participating manufacturers 

must contain finalized data. Likewise, as discussed in Section II.B.4, clarifications will 

also be added for heavy-duty pickup truck and van manufacturers specifying that the 

EOY reports must contain finalized data. 

NHTSA is also clarifying requirements for submitting information on exempted 

vehicles for both participating and non-participating manufacturers. In the final rule, 
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NHTSA regulations require manufacturers to provide a plan describing the vehicles 

exempted as off-road vehicles in the EOY and final reports. EPA regulations require the 

plan be submitted only in the EOY report with finalized data. NHTSA is modifying its 

regulations to align with the EPA provisions and will require information on exempted 

vehicles to be submitted only with the EOY report with finalized data. This single 

reporting will provide NHTSA with the information needed to assess compliance. 

As these clarifications are consistent with the agencies’ intent as expressed in the 

final rule preamble (to consolidate duplicative reporting requirements), and the change 

will reduce reporting burdens without sacrificing necessary compliance data, NHTSA 

does not believe that this alignment with be controversial. 

(5) Vocational Tractor Compliance

The final rule allows tractors meeting the definition of vocational tractors in 49 

CFR 523.2 to comply with requirements for heavy-duty vocational vehicles. However, if 

a manufacturer is found not to have applied this allowance in good faith in its application 

for certification, it may not use this compliance path (it must comply instead with the 

tractor standards). EPA provides the complete requirements for vocational tractors in 40 

CFR 1037.630. However, the NHTSA regulations mistakenly reference EPA’s 

vocational tractor provisions as 40 CFR 1037.610 (the regulation for “vehicles with 

innovative technologies”) instead of 40 CFR 1037.630. Therefore, NHTSA is correcting 

the reference specified in 49 CFR 535.5(c)(5).
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(6) Fuel Consumption Calculations and Credit Equations

NHTSA is making a minor technical revision to address rounding inconsistencies

when converting CO2 values to equivalent fuel consumption values in the Greenhouse 

Gas Emissions Model (GEM) simulation tool. The GEM is programmed to use 

manufacturer-provided vehicle specifications to derive the CO2 emissions (in grams CO2

per ton-mile) and fuel consumption performance (in gallons per 1000 ton-miles) of 

vehicles. Both the CO2 emissions and fuel consumption values are calculated and 

rounded to eight decimal places and then round once again in accordance with each 

agency’s regulations. For NHTSA, the equivalent fuel consumption value derived by the

GEM must be rounded to the nearest 0.1 gallons per 1000 ton-mile (49 CFR 535.6(b)(3)). 

For EPA, the CO2 emissions value must be rounded to the nearest 1 gram of CO2 per tonmile (40 CFR 1037.701). The rounding can cause differences in equivalency between the 

performance results in the EPA and NHTSA programs. For compliance, vehicles are 

grouped into subfamilies based upon the GEM-derived CO2 emissions value for the EPA 

program and the GEM-derived fuel consumption value for the NHTSA program. 

Rounding can cause differences in how vehicles are grouped in the EPA and NHTSA 

programs, creating compliance accounting differences that the agencies did not intend. 

The agencies intended that the same vehicles would be grouped in each subfamily for the 

EPA program and the NHTSA program. To address the rounding inconsistencies, 

NHTSA is amending 49 CFR 535.6(b)(3) to clarify that equivalent fuel consumption 

values in the GEM must be derived from the CO2 value rounded to the nearest whole 

number and expressed to the nearest 0.1 gallons per 1000 ton-mile. This change will 
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ensure the same vehicles will be grouped into a single subfamily for compliance under 

both programs. Hence, the agencies are releasing a revised version of GEM, GEM 

v2.0.1, with this rulemaking which incorporates this change in conversion methodology. 

There is also a typographical error in the equations that are used to determine fuel 

consumption credits in the NHTSA regulations (49 CFR 535.7). In the existing 

equations, fuel consumption credits for heavy-duty vehicles and engines are calculated by 

multiplying by a factor of 102for heavy-duty pickup trucks and vans and for engines, and 

by a factor of 103for vocational vehicles and tractors. However, the correct factors for 

multiplication should be 10-2for heavy-duty pickup trucks and vans and for engines and 

10-3 for vocational vehicle and tractors. These factors ensure the proper conversion and 

alignment between EPA and NHTSA calculated credits. Therefore, NHTSA is amending 

its fuel consumption credit equations in 49 CFR 535.7(b)(9), (c)(11) and (d)(11) to reflect 

the correct factors for multiplication and does not anticipate any objections to this. 

(7) Definitions for Incomplete and Complete Heavy-Duty Pickup Trucks and 

Vans

In the final rule, EPA included separate definitions to describe complete and 

incomplete vehicles in the vocational vehicle and tractor regulatory subcategories and for 

vehicles in the heavy-duty pickup truck and van subcategory. NHTSA included the same 

definitions for incomplete and complete vocational vehicle and tractors in its regulations 

but omitted the ones for pickup trucks and vans. Therefore, NHTSA is adding a 

reference to the EPA definitions for complete and incomplete pickup trucks and vans in 

49 CFR part 523. NHTSA believes these changes are non-controversial as they will 
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simply help to clarify characteristics in the construction of complete and incomplete 

heavy-duty pickup trucks and vans already existing in EPA’s regulations. 

(8) Off-road Exclusion Petitioning Process

EPA and NHTSA requirements specify that heavy-duty off-road vehicles meeting 

the criteria in 40 CFR 1037.631 and 49 CFR 535.3(g) are exempted without request from 

vehicle standards, and manufacturers with off-road vehicles not meeting the enumerated 

criteria may petition for exemption by describing how and why their vehicles should 

qualify for exclusion (49 CFR 535.8(h)(6)(ii)). While this voluntary process is already 

described in this provision, NHTSA believes that manufacturers would benefit from 

additional language highlighting timing considerations should they plan to rely upon such 

a petition. While a manufacturer may submit a petition at any time, NHTSA 

recommends that they be submitted early enough in advance of the model year to ensure 

that a determination can be made by the agencies, and should the vehicles fail to be 

excluded, the manufacturer has sufficient time to submit and obtain approved certificates 

of conformity from EPA required prior to first commercial sale. Therefore, NHTSA is 

adding this recommendation to the existing provision for off-road exemptions in 49 CFR 

535.8(a). As this amendment merely highlights existing timing considerations, and does 

not change any aspect of the process or requirements, NHTSA believes it will be noncontroversial. 
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D. EPA Regulatory Action on HD GHG Amendments

EPA is amending 40 CFR parts 86, 1036, 1037, 1065, and 1066 to correct 

typographical errors, clarify test procedures and certification procedures, and correct the 

regulations to make them consistent with the intent expressed in the preamble to the final 

rules (see 76 FR 57106). If EPA receives adverse comment on a distinct EPA provision 

in this subsection, then EPA will publish a timely withdrawal in the Federal Register 

indicating which provisions EPA is withdrawing. The provisions that are not withdrawn 

will become effective on the date set out in the DATES section of this action. EPA would 

address all public comments in a subsequent final rule based on the EPA-proposed rule

accompanying this joint direct final rule. 

A comparison of the original and amended regulatory text is provided in a 

memorandum to the dockets for this rulemaking.14

(1) Regulatory Changes to 40 CFR Part 1036 

EPA is revising portions of the regulations in 40 CFR part 1036, as described 

below. 

EPA is revising §§ 1036.5, 1036.150, and 1036.615 to address typographical 

issues to correct regulatory citations within the regulations.

 

14 Hicks, M. and A. Cullen. Memorandum to Dockets EPA-HQ-OAR-2012-0102 and NHTSA2012-0152. Heavy-Duty Engine and Vehicle Greenhouse Gas Emissions and Fuel Consumption 

Regulatory Changes. March 2013.
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EPA is correcting § 1036.150(g)(2) and (g)(3) to change the assigned additive 

deterioration factor (DF) for nitrous oxide (N2O) and methane (CH4) emissions 

from 0.02 to 0.020 g/hp-hr to account for the appropriate number of significant 

digits.

EPA is amending § 1036.225 to clarify that the CO2 FEL is not required on the 

emission control information (ECI) label according to the provisions in §

1036.135.

EPA is clarifying that the CH4 and N2O emission standards apply to all testable 

configurations in § 1036.205.

EPA is adding a definition of “preliminary approval” to § 1036.801.

(2) Regulatory Changes to 40 CFR Part 1037 

EPA is also revising portions of the regulations in 40 CFR part 1037 to correct 

technical errors and provide additional clarity in the regulations. 

Heavy-Duty Pickup Truck and Van Regulations: EPA is amending several 

provisions in §§ 1037.15 and 1037.104 to specify which parts of 40 CFR part 86 

apply to these vehicles and to specifically reference portions of 40 CFR part 86 in 

40 CFR part 1037. EPA also is revising the language in § 1037.150(a)(2) to make 

it consistent with the preamble to the final rule which stipulates that the entire 

heavy-duty pickup truck and van fleet must be certified to qualify for early credits

(see 76 FR 57245). Also, EPA is clarifying how heavy-duty pickup truck and van 

subconfigurations are selected for testing in § 1037.104(d)(9)(i) through (iii). 
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EPA is also revising § 1037.104(g)(2)(ii), (g)(2)(iv), and (g)(5) to clarify the 

approach for estimating analytically derived CO2 emission rates (ADCs). 

Air Conditioning (A/C) Leakage Provisions: The MY2017-2025 Light-Duty 

GHG and Fuel Economy Rule separated 40 CFR 86.1866 into four sections for 

clarity. The A/C leakage section moved to 40 CFR 86.1867-12. Thus, EPA is 

amending § 1037.115 to reflect this change. In addition, EPA is revising § 

1037.115 because the procedure for determining the hydrofluorocarbon (HFC)

leakage rate for air conditioning systems with alternate refrigerants is already 

addressed in SAE J2727, which is incorporated by reference in 40 CFR 86.1, and 

therefore does not need to be included in § 1037.115.

Labeling clarification: EPA is clarifying in § 1037.135 that the emission control 

label for the vehicle only requires a statement regarding the size of the fuel tank 

for vehicles that contain an evaporative canister for controlling emissions.

Typographical fixes: EPA is addressing the typographical errors in § 1037.135 

relative to labeling, § 1037.501 related to the trailer specification, and § 1037.520 

which includes a weight reduction explanation.

EPA is clarifying that the general requirements for obtaining a certificate of 

conformity and EPA’s authority to perform confirmatory testing on vehicles, 

including the vehicles used to determine Falt-aero (see § 1037.201).

EPA is revising § 1037.550 to change the nomenclature used for the vehicle speed 

variable from S to v to be consistent with 40 CFR part 1065. EPA is also 

removing the torque control option for testing post-transmission hybrid systems 
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because it causes testing issues when the vehicle is shifting and braking. In 

addition, removing torque control mode from the dynamometer control options 

reduces lab-to-lab variability.

EPA is clarifying the regulatory text in § 1037.620(a)(3) to cover instances where 

the secondary manufacturer who would hold the vehicle GHG certificate may be a 

small business that is exempted from the GHG regulations. 

EPA is revising § 1037.660 related to the automatic engine shutdown (AES)

provisions. § 1037.660(c) currently allows manufacturers to obtain a discounted 

credit for installing AES systems that expire prior to the end of the vehicle’s life

based on the ratio of the set point relative to 1,259,000 miles.

15

 EPA is not 

revising that provision, except to change the regulatory provision numbering from 

§ 1037.660(c) to § 1037.660(c)(1). However, sSimilar to the reasons which 

supported the development of vehicle speed limiter flexibilities, an automatic 

engine shutdown system can be developed to alleviate other potential concerns 

that impede its adoption. For example, some amount of idling may be needed for 

truckers who experience significant ambient temperature excursions that would 

necessitate extended idling or for idle reduction technologies, such as auxiliary 

power units, that malfunction and necessitate extended idling. A remedy to these 

 

15 The basis for the lifetime mileage assumption for heavy-duty tractors is discussed in the 

Regulatory Impact Analysis for the Final Rule on page 2-69. Available in Docket # EPA-HQ-OAR-2010-

0162-3634
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concerns would be to design the AES such that it allows for a predetermined 

number of hours per year of idling. EPA is adding § 1037.660(c)(2) to 

appropriately quantify the CO2 emissions and fuel consumption of a partial AES 

system by discounting the AES input to GEM. EPA is using an assumption of

1,800 hours as the annual idling time in the calculation, which is consistent with 

the final rule (76 FR 57154). EPA used 1,800 hours as the annual idling time for 

sleeper cabs because it reasonably reflects the available range of idling time cited 

in several studies, as discussed in the preamble to the final rule and in the Final

Regulatory Impact Analysis (pages 2-67 and 2-68).16 The 1,800 hours of idling 

was used in the final rule to determine the credit of 5 grams of CO2 per ton-mile 

for the use of AES systems (page 2-68 of the Final Regulatory Impact Analysis).

EPA is adding a provision to § 1037.745. This new provision clarifies

manufacturers’ liability for offsetting debits (or deficit credits) after certifying 

with emissions above the standards for three years. We want to avoid claims that 

the statute of limitations starts to apply in the first year of using debits, since this

could significantly limit our ability to adequately enforce the requirement. We 

have generally adopted this approach in other rules that allow debits to be carried 

forward a given number of model years and are later offset with credits (40 CFR

 

16 Regulatory Impact Analysis: Final Rulemaking to Establish Greenhouse Gas Emissions 

Standards and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles. August 

2011. Available in Docket # EPA-HQ-OAR-2010-0162-3634.

Comment [A2]: 4/24/2013 – Suggest adding 

some form of the EPA Response to the following 

comment into the preamble text.

EPA RESPONSE 4/25/2013: See additional edits in 

yellow on the previous page.

Comment [A3]: Suggest discussing the reasoning 

for using 1,259,000 miles and 1,800 hours in any 12-

month period. 

EPA RESPONSE: 40 CFR 1037.660(c) in the 

existing regulations already allows the use of 

expiring AES systems, which discount the value of 

the credit by the ratio of the setpoint relative to 

1,290,000 miles. The basis for this is discussed in 

the RIA on page 2-69. We are not making any 

changes to that provision, other than to change the 

numbering from 1037.660(c) to 1037.660(c)(1).

Please see the edits in the text for the 1,800 hours of 

annual idling reference.
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86.1861-04(e), 86.1864-10(o), and 86.1865-12(k)).

EPA is adding a definition of “preliminary approval” to § 1037.801.

EPA is revising the “Regulatory Sub-category” definitions in § 1037.801 to 

match the definition of “Class” in 40 CFR 1037.801, be consistent with DOT’s 

Gross Vehicle Weight Rating Classes in Table II of 49 CFR 565.15, and

aggregate the heavy-duty pickup truck and van sub-category to match the 

definition in 49 CFR 535.4.

(3) 40 CFR Part 1037 Aerodynamic Assessment

A vehicle’s design impacts the amount of power that is required to move the 

vehicle down the road. Depending on the vehicle speed, two of the largest impacts on 

GHG emissions and fuel consumption are aerodynamics and tire rolling resistance. As 

part of the Heavy-Duty GHG and Fuel Efficiency rule, manufacturers are required to 

meet vehicle-based GHG emissions and fuel efficiency standards. Compliance with the 

vehicle standard for combination tractors is determined based on a vehicle simulation tool 

called the Greenhouse Gas Emissions Model (GEM). Various characteristics of the 

vehicle are measured and these measurements are used as inputs to the model. These 

characteristics relate to key technologies appropriate for this subcategory of truck—

including aerodynamic features, weight reductions, tire rolling resistance, the presence of 

idle-reducing technology, and vehicle speed limiters. See generally 76 FR 57135.

The aerodynamic drag of a vehicle is determined by the vehicle’s coefficient of 

drag (Cd), frontal area, air density and speed. As noted in the Heavy-Duty GHG and 
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Fuel Efficiency rule, quantifying truck aerodynamics as an input to the GEM presents 

technical challenges because of the proliferation of vehicle configurations, the lack of a 

clearly preferable standardized test method, and subtle variations in measured 

aerodynamic values among various test procedures. Id. at 76 FR 57148-57151. Class 7 

and 8 tractor aerodynamics are currently developed by manufacturers using a range of 

techniques, including wind tunnel testing, computational fluid dynamics, and constant 

speed tests. 

We developed a broad approach that allows manufacturers to use these multiple 

different test procedures to demonstrate aerodynamic performance of the tractor fleet 

given that no single test procedure is superior in all aspects to other approaches. 

Allowing manufacturers to use multiple test procedures and modeling coupled with good 

engineering judgment to determine aerodynamic performance is consistent with the 

current approach used in determining representative road load forces for light-duty 

vehicle testing (40 CFR 86.129-00(e)(1)). However, we also recognize the need for 

consistency and a level playing field in evaluating aerodynamic performance. 

The agencies developed a bin structure to group aerodynamic test results for the 

proposed rulemaking, and adjusted the method used to determine the bins in the final 

rule. The agencies, while working with industry, developed an approach for the final 

rulemaking which identified a reference aerodynamic test method and a procedure to 

align results from other aerodynamic test procedures with the reference method, an 

enhanced coastdown procedure. Manufacturers will be able to use any aerodynamic 
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evaluation method in demonstrating a vehicle’s aerodynamic performance as long as the 

method is aligned to the reference method. 

As discussed in the final rules, the agencies adopted aerodynamic technology bins 

which divide the wide spectrum of tractor aerodynamics into five bins (i.e., categories) 

for high roof tractors (see 76 FR 57149). The first high roof category, Bin I, is designed 

to represent tractor bodies that prioritize appearance or special duty capabilities over 

aerodynamics. These Bin I trucks incorporate few, if any, aerodynamic features and may 

have several features that detract from aerodynamics, such as bug deflectors, custom 

sunshades, B-pillar exhaust stacks, and others. The second high roof aerodynamics 

category is Bin II, which roughly represents the aerodynamic performance of the average 

new tractor sold today. The agencies developed this bin to incorporate conventional 

tractors that capitalize on a generally aerodynamic shape and avoid classic features which 

increase drag. High roof tractors within Bin III build on the basic aerodynamics of Bin II 

tractors with added components to reduce drag in the most significant areas on the 

tractor, such as integral roof fairings, side extending gap reducers, fuel tank fairings, and 

streamlined grill/hood/mirrors/bumpers, similar to SmartWay trucks today. The Bin IV 

aerodynamic category for high roof tractors builds upon the Bin III tractor body with 

additional aerodynamic treatments such as underbody airflow treatment, down exhaust, 

and lowered ride height, among other technologies. And finally, Bin V tractors 

incorporate advanced technologies that are currently in the prototype stage of 

development, such as advanced gap reduction, rearview cameras to replace mirrors, 

wheel system streamlining, and advanced body designs. 
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The agencies developed the aerodynamic drag area, CdA, bin values for the 

tractor categories based on coastdown testing conducted by EPA using the enhanced 

coastdown test procedures adopted for the final HD GHG and Fuel Efficiency 

rulemaking. EPA tested high roof sleeper cab combination tractors from each of the 

manufacturers in order to represent the aerodynamic performance that we would expect 

from a Bin III vehicle. The test results used for the HD GHG and Fuel Efficiency final 

rule are included in Table II-1 below.17

Table II-1: Tractor CdA Values used in HD GHG Final Rule

Truck Expected Bin Source CdA (m2)

Class 8 High Roof Sleeper Cab

B-3JM2-2H-TXCR Bin III EPA Test Program 6.4

B-3JM2-4N-TXCR Bin III-IV EPA Test Program 5.7

B-3JM2-2K-TXCR Bin III EPA Test Program 6.3

C-3JM2-1B-TXCR Bin III EPA Test Program 6.2

C-3JE2-1F-TXCR Bin II-III EPA Test Program 6.7

As part of EPA’s quality checks to the enhanced coastdown test program, EPA

supplied OEMs with the coastdown test data for their individual trucks. Through postrulemaking work with one OEM, EPA found an error in the data attributable to a testing 

contractor. The contractor had entered the same coastdown run twice into the dataset 

provided to EPA for one of the trucks tested (one of 20 repeat runs was entered twice). 

As a result the truck appeared to have a CdA value of 5.7, rather than its actual value of 

 

17 U.S. EPA and NHTSA. Final Rulemaking to Establish Greenhouse Gas Emissions Standards and Fuel 

Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles – Regulatory Impact Analysis. 

August 2011. Page 2-48.
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6.6. As such, the data that should have been used to establish the aerodynamic bins for 

the high roof sleeper cabs are listed in Table II-2.

Table II-2: Tractor CdA Values used in this DFR

Truck Expected Bin Source CdA (m2)

Class 8 High Roof Sleeper Cab

B-3JM2-2H-TXCR Bin III EPA Test Program 6.4

B-3JM2-4N-TXCR Bin III EPA Test Program 6.6

B-3JM2-2K-TXCR Bin III EPA Test Program 6.3

C-3JM2-1B-TXCR Bin III-IV EPA Test Program 6.2

C-3JE2-1F-TXCR Bin II-III EPA Test Program 6.7

Since the coastdown test is an input into the aerodynamic bins, EPA is correcting 

the CdA range for the affected bin levels. The adjustment to the ranges will allow Bin 

III, which represents a SmartWay truck, to still mean exactly what was intended in the 

HD GHG and Fuel Efficiency final rule. The Bins IV and V adjustments will require the 

same level of improvement we expected in the HD GHG and Fuel Efficiency final rule. 

This amendment is a correction, so will not change the standards or the costs or projected 

emissions reductions. The HD GHG and Fuel Efficiency rulemaking estimates of 

technology costs and the resulting aerodynamic efficiency improvements were made 

separately from the test procedure normalization reflected in the bin tables. Those cost 

and technical feasibility assessments set the absolute values of the steps in the table, 

where the testing results of the five tractors in Table II-2 set the range of Bin III against 

which the rest of the aerodynamic bins are defined. Since EPA is not changing either the 

technical descriptions of the bins or the estimates of the aerodynamic loss or benefits in 

moving between bins in the table, EPA is estimating no change in HD GHG and Fuel 
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Efficiency final rulemaking costs or benefits. EPA is also not changing the input into 

GEM related to each aerodynamic bin; therefore, this change has no impact on the GHG 

or on fuel consumption standards.

EPA is making the adjustments shown in Table II-3 to correct the technical error 

in the coastdown data used in the HD GHG and Fuel Efficiency final rule. Manufacturers 

will use these corrected aerodynamic bin levels in their end of year reports for all 2013 

MY and later tractors. 

Table II-3: Revised Table in § 1037.520(b)

High-Roof Sleeper Cabs

If your measured CDA 

(m2) is . . .

Then your Bin Level 

is...

Then your CD input is . . 

.

≥ 7.6 Bin I 0.75

6.8-7.5 Bin II 0.68

6.3-6.7 Bin III 0.60

5.6-6.2 Bin IV 0.52

≤5.5 Bin V 0.47

(4) Regulatory Changes to 40 CFR Parts 1065 and 1066

EPA is restoring text to § 1065.610(c)(3)(i) through (iii) which was inadvertently 

removed in the final rule adopting standards for Category 3 marine diesel engines (75 FR 

22896, April 30, 2010). This text was most recently published in the final rule adopting 

standards for locomotive engines and Category 1 and Category 2 marine diesel engines 

(73 FR 37325, June 30, 2008).

EPA is also revising portions of the regulations in 40 CFR part 1066 to clarify test 

procedures. Specifically, § 1066.310(b) is revised to clarify the coastdown process and 

simplify the anemometer calibration process.
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(5) Regulatory Changes to 40 CFR Part 85 

EPA is revising § 85.525 to separate the light-duty and heavy-duty fuel 

conversion regulations to provide clarity regarding the applicability of the fuel 

conversion regulations to heavy-duty pickup trucks and vans. 

(6) Regulatory Changes to 40 CFR Part 86 

EPA is also revising portions of the regulations in 40 CFR part 86. First, EPA is 

revising § 86.010-18(q) to provide a mechanism for engine manufacturers to identify 

engines which are only suitable for installation in hybrid applications due to the on-board 

diagnostics (OBD) calibration. Manufacturers who opt to produce a unique set of 

engines for hybrid applications will include a compliance statement on the ECI label that 

states “for use in hybrid applications only.”

Second, EPA is revising portions of § 86.1865-12 to clarify the provisions that 

specifically apply to the heavy-duty pickup trucks and vans subject to 40 CFR 1037.104. 

Third, EPA is removing §§ 86.007-23(n) and 86.1844-01(j), which describe how 

to report CO2, N2O, and CH4 emissions. There is no need or benefit for manufacturers to 

submit greenhouse gas emission data in the model years before emission standards apply 

for those pollutants. 

(7) Summary of Heavy-Duty GHG Amendments

EPA does not expect that these minor revisions to 40 CFR parts 85, 86, 1036, 

1037, 1065, and 1066 will have any adverse cost impact to the manufacturers. There are 

no testing costs associated with the revisions. There is no environmental impact 

associated with this regulatory action because this rulemaking does not change the heavy-
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duty engine and vehicle greenhouse gas emission standards that manufacturers have to 

meet; it simply makes some minor amendments to the regulations.

III. EPA Technical Amendments

A. Replacement Engines

In 1996, EPA adopted a provision allowing manufacturers in limited 

circumstances to produce new, exempt engines for replacing failed engines (61 FR 

58102, November 12, 1996). With this approach, manufacturers have been able to make 

new, exempt engines in cases where engines certified to current standards do not have the 

physical or performance characteristics needed to power the equipment with the old 

engine. Without this provision, some equipment owners would have been forced to 

prematurely scrap otherwise working equipment (sometimes worth millions of dollars), 

because no engine meeting current emission standards could be adapted for installation in 

the space occupied by the original engine.

EPA later added language to the replacement engine exemption to address the 

complications related to producing partially complete engines for replacement purposes, 

and to address the need to produce and sell replacement engines such that they would be 

available to operators with a critical need to avoid extended downtime in the case of 

engine failure (73 FR 59034, October 8, 2008). This expanded approach allowed 

manufacturers to sell a limited number of new, exempt replacement engines without 

taking the steps that would otherwise be required to document the need for the exemption 

and to arrange for the proper disposition of the old engine. Along with this expanded 

approach, EPA added circumvention language to describe the overall purpose of the 
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replacement engine exemption in an attempt to prevent manufacturers and operators from 

using exempted engines in ways that were unnecessary and/or detrimental to the 

environment. In particular, this text states that the provisions § 1068.240 are “intended to 

allow for replacement of engines that fail prematurely . . .” This language has been 

interpreted to mean that replacement engines may be used for no other purpose.

Since then, EPA has found that the circumvention language has had some 

unintended consequences. For example, California has adopted requirements for 

operators to reduce emissions from in-use equipment, which has led to a desire to install 

new replacement engines that are cleaner than the old engines. It is often the case that it 

is infeasible or impractical to install replacement engines certified to current standards, 

but suitable replacement engines designed to meet an intermediate level of emission 

standards are available. The circumvention language may prevent operators in 

California from achieving overall emission reductions that would result from upgrading 

their existing equipment with cleaner engines in this manner. It may also be the case that 

an engine will simply wear out, rather than experiencing premature failure, well before 

the equipment in which it is installed is at the end of its life. Under the current 

regulation, an operator under these circumstances would need to install a new engine 

certified to current standards, or find a used engine, to keep the equipment operating.

EPA continues to believe that new, exempt replacement engines should only be 

used in cases where a currently certified engine cannot practically be installed to power 

the old equipment. EPA believes the regulatory language without our description of 

intent to prevent circumvention serves this purpose without the unintended consequences 
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described above. EPA is therefore removing the circumvention provisions from the 

regulations in § 1068.240. EPA expects manufacturers and operators following the 

regulations to continue to use the exemption provisions appropriately and not for the 

purpose of circumventing the emission standards. EPA is adding language to explicitly 

limit this provision to equipment that has been in service 25 years or less (at the point of 

installation) so that manufacturers and operators do not use this provision to keep in 

operation older dirtier, equipment beyond the normal lifetime of the equipment, by 

continually using new engines to replace old engines. EPA has adopted this same 

restriction for stationary engines under 40 CFR 60.4210(i), except that the maximum 

equipment age is 15 years. EPA will continue to monitor compliance with the exemption 

provisions and will consider any appropriate changes to the regulation in the future to 

ensure that the exemption is properly used toward this purpose. This 25-year limit does 

not apply for marine diesel engines, since those engines are subject to separate 

replacement engine provisions.

The rule tracked option specified in § 1068.240(b) also includes an additional step 

to qualify for the replacement engine exemption for equipment not experiencing 

premature engine failure. In particular, manufacturers would need to make a 

determination that the replacement engine is designed with the greatest degree of 

emission control that is available for the particular application. For example, if the 

engine being replaced was built before the Tier 1 standards started to apply and engines 

of that size are currently subject to Tier 2 standards, the manufacturer would need to also 

consider whether it produces any Tier 1 or Tier 2 engines with the appropriate physical 
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and performance characteristics for replacing the old engine. If the manufacturer 

produces a Tier 1 engine with the appropriate physical and performance characteristics, 

engines emitting at levels above the Tier 1 standards do not qualify for an exemption. 

The requirement to use the cleanest available engine fits with the intent of facilitating 

voluntary incentive programs involving replacement engine upgrades toward the goal of 

reducing emissions from in-use equipment, but without imposing a requirement that 

would involve new technology development or impractical equipment design changes.

This provision has already been in place for marine diesel engines in § 1042.615. In the 

case of equipment experiencing premature engine failure, we will continue to apply the 

simpler requirement that the replacement engine must meet emission standards that are 

the same as or better than the standards that apply to the old engine. By adopting this 

provision in § 1068.240, it would apply automatically to marine diesel engines, so we are 

proposing to remove it from § 1042.615.

EPA is also adjusting the provisions related to the disposition of the old engine in 

§ 1068.240(b)(4). To be re-introduced into U.S. commerce, the old engine must either 

meet current emission standards or qualify for an exemption as if it were a new engine. 

The old engine could be re-used as a replacement engine for a different piece of 

equipment. Under this approach, an engine made from all new parts and an engine built 

with a used engine block and any mix of new or used additional parts would be treated 

the same way. For example, the recycled replacement engine would be subject to all the 

demonstrations and documentation requirements of § 1068.240(b), and it would count 

toward the allowance to produce a limited number of replacement engines under § 
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1068.240(c). For engines that are not re-introduced into U.S. commerce, manufacturers 

must destroy the old engine or confirm that it has been destroyed. These changes will 

further address the concern expressed in the circumvention language described above; in 

particular, EPA believes it is necessary to prevent the possibility of these old engines 

being installed in new equipment.

EPA is also adding some clarification to the regulations to address questions that 

have arisen, as well as making the following changes to this section:

Revising the labeling requirements to account for the possibility of using a new 

replacement engine to replace a previously exempted replacement engine § 

1068.240(b)(6). To the extent that the revised label statement differs from that 

specified by California ARB, we would expect to approve an adjusted statement that 

allows for a single, 50-state label under § 1068.201(c).

Adjusting the reporting deadline for untracked replacement engines under § 

1068.240(c). This change would allow manufacturers some time after the end of the 

calendar year to make the determinations and to take the required steps to fulfill the 

tracking requirements for replacement engines under § 1068.240(b). Any engines for 

which these steps and determinations are incomplete by the deadline for the report 

would need to be counted as untracked replacement engines. Further, to account for 

prevailing practices and typical timelines for replacement engines, we are moving 

back the deadline for this report from February 15 to March 31. 
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Revising § 1068.240(c)(1) to specify that manufacturers may base sales limits for the 

untracked option on total U.S. production of certified and exempted engines together

(including stationary engines).

Adding language to clarify that § 1068.240(e) applies only for engines produced 

under a current, valid certificate. An exemption under § 1068.240(b) or (c) would be 

required to produce an engine that is identical to one that is no longer certified, even 

if the engine was formerly certified to standards (or a Family Emission Limits) that 

are at least as stringent as the current standards.

Clarifying that the provisions in § 1068.240(d) related to partially complete engines 

also apply for “current-tier” replacement engines exempted under § 1068.240(e).

Adding a statement to § 1042.615 for marine diesel engines to clarify our predetermination that certified Tier 4 engines do not have the appropriate physical and 

performance characteristics for replacing older engines in marine vessels. This policy 

was established in our June 30, 2008 final rule (see 73 FR 37157). 

In addition, we are revising § 1068.1 to correct two errors regarding the applicability 

of part 1068. First, we are restoring highway motorcycles to the list of categories that are

not subject to part 1068. This was added, but then inadvertently removed, when we were 

completing two parallel rulemakings. Second, we are adding a reference to 40 CFR part 

85 to identify how part 1068 applies in certain circumstances for heavy-duty highway 
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engines. These changes are intended to clarify and reinforce existing requirements 

without modifying the underlying programs in any way.

B. Nonroad Diesel Engine Technical Hardship Program

EPA is amending the nonroad diesel engine technical hardship program to 

facilitate EPA granting exemptions to address certain hardship circumstances that were 

not considered when the original 2004 final rule was published. EPA adopted Tier 4 

standards for nonroad diesel engines under 40 CFR part 1039 in 2004 (69 FR 38958, June 

29, 2004). To meet these standards, engine manufacturers are pursuing development of 

advanced technologies, including new approaches for exhaust aftertreatment. Equipment 

manufacturers will need to modify their equipment designs to accommodate these new 

engine technologies and the corresponding changes to engine operating parameters (such 

as operating temperatures and heat rejection rates). To provide flexibility for equipment 

manufacturers in their efforts to respond to these engine design changes, the Tier 4 

standards included the Transition Program for Equipment Manufacturers. Flexibilities 

allowed under this program include delaying compliance with small-volume equipment 

models for several years or using allowances in the first year to manage the transition to 

the Tier 4 engines.

The Transition Program for Equipment Manufacturers is intended to allow 

nonroad equipment manufacturers wide discretion to manage their product development 

timeline. Equipment manufacturers may comply either based on a percent of their 

production (generally for high-volume manufacturers, as described in § 1039.625(b)(1)), 

or based on a maximum number of exempted pieces of equipment (generally for low-
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volume manufacturers, as described in § 1039.625(b)(2)). At the same time, the 

regulations include at § 1039.625(m) an acknowledgement that equipment manufacturers 

might face a wide range of circumstances, including cases where engine manufacturers 

might be late in providing compliant engines to nonintegrated equipment manufacturers 

such that the specified allowances are insufficient to avoid a disruption in the equipment 

manufacturer’s production schedule. The technical hardship provision at § 1039.625(m) 

allows EPA to make a judgment that an equipment manufacturer that buys engines from 

another company, through no fault of its own, needs additional allowances to manage the 

transition to Tier 4 products. The regulation specifies a maximum allowance of 150 

percent of a manufacturer’s annual production (relative to § 1039.625(b)(1)), or a total of 

1,100 allowances (relative to § 1039.625(b)(2)). The regulation also provides economic 

hardship provisions under § 1068.255; however, eligibility depends on manufacturers 

showing that their solvency is in jeopardy without relief. Economic hardship therefore 

serves as a flexibility provision of last resort.

As the compliance dates for the Tier 4 standards approach, equipment 

manufacturers have described several scenarios where the technical hardship provisions 

are too restrictive to address their circumstances. For example, engine manufacturers 

have in some cases delayed delivery of Tier 4 engines until six or even twelve months 

after the Tier 4 standards start to apply, which could force equipment manufacturers to 

use up all their allowances under § 1039.625(b) in the first year of the new standards. 

The maximum number of allowances under § 1039.625(m) would cover a good portion 
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of the second year of the Tier 4 standards, but we have heard how this too is inadequate 

to allow equipment manufacturers to respond to late deliveries of compliant engines. 

As another example where additional flexibility may be warranted, corporate 

acquisitions can cause equipment manufacturers to find themselves disadvantaged with 

respect to allowances because two companies have become a single company for 

purposes of regulatory compliance. Taken to an extreme, the combined company could 

exceed its allowances under § 1039.625(b) on the day of the merger because each of the 

separate companies may have used allowances that, taken together, exceed the specified 

thresholds for a single company. The combined company may apply for technical 

hardship under § 1039.625(m), but we have seen that this too can provide insufficient 

relief for equipment manufacturers trying to incorporate Tier 4 engines into their 

equipment.

In these cases, the maximum allowable relief under § 1039.625(m) is insufficient 

to allow equipment manufacturers to transition to meeting Tier 4 requirements without 

disrupting their ability to continue producing their equipment models. There have also 

been cases where a company would meet the criteria to qualify for consideration for 

technical hardship under § 1039.625(m) except that the regulation disallows technical 

hardship relief for all engines above 560 kW and provides only limited relief for engines 

above 37 kW. The regulation also provides only limited relief for companies that are not 

small businesses. In these cases, no additional relief is available under § 1039.625(m), 

which again leaves equipment manufacturers unable to continue producing their 

equipment models. We are amending the Transition Program for Equipment 
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Manufacturers in three ways to address these concerns. First, we are removing the 

qualifying criteria so that any equipment manufacturer may apply for technical hardship 

relief under § 1039.625(m) for any size engine, rather than limiting the technical hardship 

relief to small businesses and to engines within certain power categories. We believe it is 

more appropriate to rely on our discretion to evaluate each hardship application on its 

merits rather than automatically precluding hardship relief based on certain 

characteristics of the engine or the company. If hardship relief is not appropriate because 

of an engine’s power rating or a company’s size or financial standing, we will not 

approve the request. 

Second, we are removing the maximum number of allowances we can approve 

under § 1039.625(m), for both percent-of-production (currently 150 percent) and smallvolume allowances (currently 1,100 units), and we are removing the deadlines for 

exercising those additional allowances. We have learned that the specified restrictions on 

hardship allowances are in some cases too limiting to address the legitimate concerns 

raised by equipment manufacturers. Again, we believe it is most appropriate to resolve 

issues of extent of relief once an equipment manufacturer has demonstrated that relief is 

appropriate, rather than limiting it a priori. We will not approve a greater number of 

technical hardship allowances than is needed to meet the established objectives. Finally, 

for additional small-volume allowances under § 1039.625(b)(2) and (m)(4), we may 

waive the annual limits on the number of allowances instead of or in addition to granting 

additional hardship allowances. There may be times when manufacturers only need 
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approval to use up their regular allowances at a faster pace than the regulations currently 

allow.

An additional concern has come to our attention as it relates to marine engines. 

Vessel manufacturers may use certified land-based engines in marine vessels as long as 

the engines are not modified from their certified configuration (see § 1042.605). We 

adopted this provision with the understanding that, given the additional technological 

challenges of operating engines in a marine environment, marine standards are set to be 

no more stringent than land-based standards and are often set at a level somewhat less 

stringent than the standards that apply to the land-based engines. Vessel manufacturers 

have used these provisions extensively to access a wide range of engine models that are 

not available in a certified marine configuration. The part 1039 Tier 4 standards have 

made this more complicated. The Tier 4 standards for most sizes of land-based engines 

are much more stringent than the Tier 3 marine standards, which will continue to apply 

for many Category 1 engines. Engine distributors supplying product to vessel 

manufacturers have reported that several engine models will not be available to them in 

the transition period. In that way, vessel manufacturers are much like nonroad equipment 

manufacturers, except that the vessels are not actually required to use engines meeting the 

more stringent standards now or, for engines below 600 kW, in the foreseeable future. It 

would be a natural solution to use allowances under § 1039.625, but the regulations 

specifically require that vessel manufacturers may use only certified land-based engines 

under § 1042.605. There is a risk that this gap would significantly limit their ability to 

continue producing vessels in the near term. We are addressing this by revising 40 CFR 
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part 1042 to specifically allow vessel manufacturers to use allowances under § 1039.625 

for certain model year 2013 engines installed in marine vessels. This provision does not 

apply for engines at or below 19 kW, since the land-based and marine standards for those 

engines are very similar. This provision also does not apply for engines above 600 kW 

because the dynamic for designing and certifying those high-power engines allows for a 

greater expectation that they will be certified in a marine configuration. We expect no 

negative environmental impact because the engines will be meeting the nonroad Tier 3 

standards, which will continue to be at least as stringent as the standards that currently 

apply for marine engines. Since this is only a temporary measure, vessel manufacturers 

will either need to use Tier 4 land-based engines or find certified Tier 3 marine engines

starting with the 2014 model year. 

There are further minor changes to the regulations to clarify some of the detailed 

transition provisions for nonroad diesel engines, as follows:

Revising § 1039.104(g) to remove the limitations on the number of engines using the 

specified alternate FEL caps. Manufacturers have pointed out that this expanded 

flexibility would address the same concerns as described in this section for 

transitioning to the Tier 4 standards, but there would be no net environmental impact 

since manufacturers would need to produce low-emission engines that generate 

emission credits to offset the additional credits used by transition engines certified to 

with higher FELs. We are also revising the regulation to specify that the same 

Temporary Compliance Adjustment Factor is the same whether an engine is subject 

to NOx+NMHC standards or NOx-only standards. The revision also addresses Tier 3 
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carry-over engines that would need to certify to the alternate FEL caps after the Tier 4 

final standards take effect.

Adding text to § 1039.625(e) to clarify that exempted engines may meet standards 

that are more stringent than those specified in the regulation. This change is intended 

only to avoid the unintended consequence of disallowing a manufacturer from 

making an engine that was cleaner than it needed to be. Even though these engines 

are cleaner than they need to be under the replacement-engine exemption, it is still the 

case that these engines are being exempted from the standards that apply for certified 

engines; as such, it would be inappropriate for these engines to generate emission 

credits. 

Clarifying in § 1039.625(e) which alternate standards apply to exempted engines in 

cases where there is more than one set of standards in a given model year. For 

example, the appropriate standards for 19-56 kW engines are the Option 1 standards 

specified in § 1039.102, and the appropriate standards for bigger engines are the 

phase-out standards specified in § 1039.102.

Adjusting the provision for using interim Tier 4 engines under § 1039.625(a)(2) to 

require that manufacturers use engines that are identical to previously certified 

engines, rather than requiring that the exempt engines be certified for the new model 

year. This addresses an administrative complication related to certifying exempted 

engines, without changing the requirements that apply.

Comment [A4]: 4/24/2013 – Suggest including 

some form of the EPA Response to the preamble 

language.

4/26/13 EPA RESPONSE: See text edits highlighted

in yellow. 

Comment [A5]: Would a manufacturer generate 

credits for meeting more stringent standards?

EPA RESPONSE: The change is intended only to 

avoid the unintended consequence of disallowing a 

manufacturer from making an engine that was 

cleaner than it needed to be. Emission credits are 

generated and used only with certified engines. 

TPEM engines are not certified. 
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C. Large SI Fuel Line Permeation

EPA is amending the required version of the SAE procedure for testing large SI 

fuel line permeation. In 2002 we adopted evaporative emission standards for nonroad 

spark-ignition engines above 19 kW (Large SI engines) (67 FR 68242, November 8, 

2002). This rule included a requirement that engines meet a permeation control standard, 

that could be demonstrated by using fuel lines compliant with SAE J2260, the latest 

version of which had been completed in 1996 (see 40 CFR 1048.105). This SAE 

standard effectively established a level of permeation control that had been widely used 

with automotive products. In adopting this requirement, we expected manufacturers to 

find “off-the-shelf” automotive-grade products for the nonroad engines and equipment. 

In 2008, we revised this requirement by changing the regulation to reference the 

2004 version of SAE J2260, which had been finalized after the initial rulemaking (73 FR 

59034, October 8, 2008). As noted in our proposed rule, we understood the purpose and 

effect of the change in the SAE standard to be substantive with regard to the permeation 

measurement procedure, but not necessarily with regard to the stringency of the standard. 

The revised SAE protocol specifies a tighter numerical standard, but this corresponded to 

an offsetting change from a methanol-based test fuel to an ethanol-based test fuel. 

Switching to ethanol improves the representativeness of the procedure, and it is widely 

understood that ethanol permeates through fuel-system materials less aggressively than 

methanol. It is also clear the fuel change would have a non-uniform effect on different 

fuel-system materials, but our overall expectation was that fuel lines meeting the 1996 

version of the standard would also meet the 2004 version of the standard. Following the 
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proposed rule, we received no comments either supporting or contradicting our 

understanding that updating to the new standard would have no significant effect on the 

stringency or practicability of the standard. 

Since completing the 2008 rulemaking, we have received information indicating 

that the revision of the regulation to refer to the newer version of SAE J2260 was having 

a substantive effect on manufacturers’ ability to meet the standard. First, it seems that 

automotive manufacturers have moved beyond the SAE J2260 standard to develop their 

own proprietary methods of sourcing fuel lines from their suppliers. Since the 

evaporative emission standards for automotive products involve whole-vehicle 

measurements in an enclosure, manufacturers have the option to pursue different 

strategies of balancing emissions from fuel-line permeation with emissions from other 

sources. In effect, there is no longer a level of emission control or a type of fuel line that 

we can characterize simply as "automotive-grade". It is also the case that motor vehicle 

manufacturers buy fuel lines in large quantities of pre-formed parts, rather than buying 

large spools of fuel line that can be cut and formed for a particular application.

Second, it appears that fuel line suppliers have a very limited ability or 

willingness to supply fuel lines that they will describe as meeting the 2004 version of 

SAE J2260. It is not clear whether this is a result of a difference in stringency between 

the two versions of the standard, or merely that fuel-line suppliers have moved beyond 

the SAE standard to conform to separate specifications from individual automotive 

manufacturers. In any case, Large SI equipment is not manufactured in sufficient 

numbers to greatly influence the fuel line manufacturers’ activities, which has prevented 
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Large SI equipment manufacturers from being able to find and use fuel lines meeting the 

exact specification in the regulations.

We are addressing this by again revising the regulation, this time to specify that 

either the 1996 or 2004 version of SAE J2260 provides an acceptable level of control for 

producing compliant Large SI engines and equipment. We do not believe this will have a 

significant effect on the stringency of the standard. However, to the extent that this 

modifies the stringency of the existing fuel-line permeation standards at all, it only 

revises it back to the level of permeation control that we adopted originally in 2002. We 

note also that the regulations from the California Air Resources Board continue to rely on 

the 1996 version of SAE J2260. This change therefore allows for a unified national 

approach to fuel-line permeation standards.

D. Small SI Amendments 

Since the first emission standards for small spark-ignition (SI) engines (< 19kW), 

EPA and the California ARB have required the same basic exhaust emission test 

procedures and durability aging requirements. Both agencies have accepted exhaust 

emission test results on either agency’s test fuel for purposes of certification. This has 

traditionally meant that for small SI engines used in either handheld or non-handheld 

equipment, EPA would accept exhaust emission test results based on either its Indolene 

test fuel (specified at 40 CFR 1065.710) or on California test fuel (specified at section 

2262 in the California Code of Regulations (13 CCR 2262)). In 2008, when EPA 

promulgated the current small SI exhaust emission standards, the California test fuel, 

commonly referred to as California Phase 2 gasoline or CA RFG 2, was a seven pound 
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per square inch (psi) Reid Vapor Pressure (RVP) gasoline which had approximately 11 

percent methyl tertiary butyl ether (MTBE) as an oxygenate additive. This test fuel had 

been used in the California small off road emission (SORE) program since 1995. 

Our 2008 final rule (73 FR 59034, October 8, 2008) included provisions (see § 

1054.145(k)) indicating that EPA would not accept carryover exhaust emission 

certification data on CA RFG 2 after the 2012 model year. However, we left open the 

possibility of continuing to accept carryover exhaust emission test data on CA RFG 2 

subject to the provisions of 40 CFR 1065.10, 1065.12 and 1065.701, which would permit 

EPA to approve its continued use if it does not affect the manufacturers’ ability to show 

that the affected engines would comply with all applicable emission standards using the 

fuel specified by EPA in 40 CFR 1065.710. Manufacturers have recently provided 

emissions data meeting the regulatory requirements listed above and EPA has permitted 

the use of CA RFG 2 (California Phase 2 gasoline) for certification for the 2013 model 

year.

18

 

Recently, California adopted new requirements for their gasoline certification test 

fuel for nonroad engines. Over the period from 2013-2020, manufacturers must 

transition from CA RFG 2 to a gasoline certification test fuel that contains 10 percent 

ethanol (E10) and has a seven psi RVP (commonly referred to as California Phase 3 

 

18 See EPA Dear Manufacturer Letter CD-12-17(NRSSI), October 29, 2012. 
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gasoline or CA RFG 3). This new requirement aligns California test fuels with their 

current in-use gasoline. 

Considering this background and recent developments, EPA is making two 

changes to its current regulatory provisions. First, EPA believes it is appropriate to 

extend its current practice of accepting exhaust emission test results for small SI engines 

to include CA RFG 3. For the 2013-2019 model years (inclusive), EPA will accept 

exhaust emission certification data generated using CA RFG 3 test fuel. Harmonization 

with California on test procedures and test fuel requirements for small spark-ignition 

engines has significant value to the engine and equipment manufacturers and users of 

those products. It allows for development and certification of only one engine for a given 

model or application by the manufacturer and allows for greater model availability and 

lower overall cost due to 50-state production. In addition, E10, which is used in CA 

RFG 3, is common in gasoline sold across the U.S. today. Therefore, permitting the use 

of CA RFG 3 in emissions certification will allow test fuel to more closely match the inuse fuel used across the U.S. Accounting for the ethanol in the fuel is likely to enhance 

engine emissions in-use durability, because the presence of oxygen in the ethanol in the 

test fuel will need to be accommodated in the engine calibrations. This will reduce 

engine operating temperatures in-use relative to engines calibrated on a test fuel without 

oxygen. 

While EPA is accepting manufacturer use of CA RFG 3 for the purposes of 

testing, EPA is not prepared to accept use of CA RFG 3 as a fully permissible 
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replacement test fuel for Indolene. Test data indicate that NMHC+NOx exhaust 

emissions using CA RFG 3 will be comparable relative to results on Federal certification 

fuel. However, due to the presence of an oxygenate (approximately 3 percent) caused by 

the inclusion of E10 in CA RFG 3, tested CO emissions will be reduced when an engine 

is tested using CA RFG 3, compared to Indolene which includes no oxygenates (see 40 

CFR 1065.710). EPA’s official test fuel is Indolene and the level of the CO emission 

standards for small SI engines (see 40 CFR 1054.103 and 1054.105) is based on the use 

of that fuel. Therefore, EPA cannot fully accept test results using CA RFG 3 as showing 

compliance with EPA CO standards, because CO test emissions showing compliance 

using CA RFG 3 do not guarantee that an engine will be able to comply with EPA’s CO 

standard using Indolene. 

Therefore, EPA will retain the option to conduct any production line, 

confirmatory, and selective enforcement audit (SEA) testing on EPA test fuel as 

specified in 40 CFR 1065.710.19 However, as an option for the manufacturers, to bring 

some uniformity and certainty to the engine development and calibration, emissions 

testing, and emissions durability assessment processes, EPA will agree to use CA RFG 3 

test fuel for any production line, confirmatory, and SEA testing if a manufacturer(s) agree 

to meet a lower CO emission standard. These values, which substantially address the 

effect of oxygenate content on CO emission rates, are 549 g/kW-hr for Classes I and II 

 

19 EPA already requires a ten percent ethanol blend for evaporative emissions testing.
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(non handheld engines) and 536 g/kW-hr for Classes III-V (handheld engines). These 

values are the same as California’s current CO emission standards (based on the use of 

CA RFG 2); they are 10-33 percent lower (depending on Class) than EPA’s CO emission 

standards (see 40 CFR 1054.103 and 1054.105) because they account for oxygenate 

content in that fuel. This does not represent a change in stringency, as the engine 

designs and calibration will not change, but CO emissions will decrease due to the 

oxygenate content of the California test fuel. This option would be available for Class I 

and II marine generators at a CO emission standard of 4.5 g/kW-hr. This value was 

derived based on the ratio of the California CO emission standards to the Federal 

emission standards for other Class I and II marine generators. This option is available on 

a family-by-family basis for all Classes of small SI engines. We consider these CO 

emission standards to be interim values for purposes of this option only. EPA may revise 

the level of its CO emission standard in the future if we propose to change the Federal 

test fuel specifications. 

Second, EPA has decided to continue accepting exhaust emissions data on CA 

RFG 2 after the 2012 model year (see 40 CFR 1054.145(k)). Manufacturers have 

provided data for both handheld and nonhandheld engines showing equivalent exhaust 

emission levels between CA RFG 2 and the gasoline specified in 40 CFR 1065.710 

(Indolene). Furthermore, the move to CA RFG 3 sets in motion a process to eliminate 

CA RFG 2 certifications in the future as would have been required under 40 CFR 

1054.145(k). Thus, to help enable an orderly and cost effective transition, EPA believes 
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it is appropriate for us to continue to accept exhaust emission test data using CA RFG 2 

for certification through the 2019 model year. We will expect engine families certified 

using CA RFG 2 carryover exhaust emission data to meet emissions standards on both 

CA RFG 2 and EPA certification test fuel as specified in 40 CFR 1065.710 for any 

production line, SEA, or confirmatory testing. 

Both of these actions apply for certification for model years 2013 to 2019, 

inclusive. EPA expects to revisit these provisions before 2020 to determine if they 

should be extended or otherwise modified. The primary EPA program using Indolene 

test fuel and meeting the current EPA emission standards remains in place for Federal 

certification for 2013 and beyond unless and until these provisions are otherwise 

modified.

We are also taking the opportunity to revise the regulatory provision in § 

1054.145(c) describing requirements related to altitude kits for handheld engines. We 

adopted those specifications based on the expectation that the Phase 3 exhaust standards 

were unchanged from the Phase 2 exhaust standards. As such, the emission standards do 

not apply at altitudes for which the manufacturer would need to rely on an altitude kit. 

The regulation should therefore be revised to no longer refer to the manufacturer relying 

on an altitude kit “to meet emission standards.” This change in the regulations is not 

intended to change current requirements, but rather simply clarifies the proper 

relationship of the altitude kit to the certified configuration.
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IV. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review 

Under Executive Order 12866 (58 FR 51735, October 4, 1993), this action is a 

"significant regulatory action” because it raises issues that may have a potential effect on 

actions taken or planned by another agency. Accordingly, EPA and NHTSA 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.

EPA’s direct final rule and NHTSA’s final rule merely clarifies and corrects

existing regulatory language. The agencies do not believe there will be costs associated 

with this rule because the costs in this program were previously accounted for under the 

existing rules (69 FR 38958, June 29, 2004; 73 FR 59034, October 8, 2008; and 76 FR 

57106, September 15, 2011). This rule is not anticipated to create additional burdens to 

the existing requirements. As such, a regulatory impact evaluation or analysis is 

unnecessary. The agencies also do not expect this rule to have substantial Congressional 

or public interest.

B. Paperwork Reduction Act

This action does not impose an information collection burden under the 

provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. Burden is defined at 5 

CFR 1320.3(b). The information collection requirements to ensure compliance with the 

provisions in these rules were covered under ICR (2394.02).

Comment [A6]: 4/24/2013 – Would like to see 

the draft ICR supporting statement describing the 

changes in reporting/recordkeeping requirements. 

4/26/13 RESPONSE: We conducted another review

of the rule to confirm the conclusion that these

amendments do not require modifications to an 

existing ICR, nor do they require a new ICR to cover 

new burdens.

Comment [A7]: Please provide the draft ICRs 

associated with the changes in the current rule.

Will EPA and NHTSA include the hourly and cost 

burden reductions that they expect the rule to 

impose? These estimates should be consistent with 

the revisions to the Information Collection Request 

that will be submitted to OMB for review under the 

PRA.

RESPONSE: This rule would be consistent with the 

burdens estimated in the existing ICR for the HD 

GHG and Fuel Efficiency Rule (ICR Tracking 

Number 2394.02), as the current rule unintentionally 

created higher burdens than was anticipated in the 

existing ICR. Thus, the existing ICR will not be 

revised. 
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The Office of Management and Budget (OMB) has previously approved the 

information collection requirements contained in the existing heavy-duty greenhouse gas 

emissions regulations under the provisions of the Paperwork Reduction Act, 44 U.S.C. 

3501 et seq. and has assigned OMB Control Number 2060–0678. The OMB control 

numbers for EPA’s regulations in title 40 of the Code of Federal Regulations are listed in 

40 CFR part 9.

C. Regulatory Flexibility Act

The Regulatory Flexibility Act (RFA) as amended by the Small Business 

Regulatory Enforcement Fairness Act of 1996 (Pub. L. 104–121, 110 Stat. 857), 

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 this rule on small entities, small entity is 

defined as: (1) a small business as defined by Small Business Administration regulations 

at 13 CFR 121.201; (2) a small governmental jurisdiction that is a government of a city, 

county, town, school district or special district with a population of less than 50,000; and 

(3) a small organization that is any not-for-profit enterprise which is independently 

owned and operated and is not dominant in its field.

After considering the economic impacts of these rules on small entities, we

concluded that this action will not have a significant economic impact on a substantial 
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number of small entities. 

This direct final rule merely corrects and clarifies regulatory provisions. In 

particular, as already adopted in the heavy-duty vehicle GHG and fuel efficiency rules, 

EPA and NHTSA are deferring standards for manufacturers meeting the Small Business 

Administration’s definition of small business as described in 13 CFR 121.201. 

There are no costs and therefore no regulatory burden associated with this rule. 

We have therefore concluded that this rule will not increase regulatory burden for 

affected small entities.

D. National Environmental Policy Act

NHTSA has analyzed this final rule pursuant to the National Environmental 

Policy Act. This rule corrects technical inconsistencies and adds minor clarifications to 

the regulatory text of the heavy-duty fuel efficiency program, finalized by rule in August 

2011. NHTSA analyzed the environmental impacts of that rule in a Final Environmental 

Impact Statement (EIS), issued in July 2011. The final rule we are issuing today is not 

anticipated to affect the stringency of the standards finalized in the August 2011 rule or to 

have environmental impacts other than those identified and analyzed in the Final EIS.

Accordingly, today’s rule will not have any significant impact on the quality of the 

human environment. Because no substantial changes have been made to the heavy-duty 

fuel-efficiency program that are relevant to environmental concerns, and in the absence 

of significant new circumstances or information relevant to environmental concerns and 
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bearing on this action, NHTSA has concluded that no further action is required under the 

National Environmental Policy Act. 

E. Unfunded Mandates Reform Act

This action contains no Federal mandates under the provisions of Title II of the 

Unfunded Mandates Reform Act of 1995 (UMRA), 2 U.S.C. 1531-1538 for State, local, 

or tribal governments or the private sector. The action imposes no enforceable duty on 

any State, local or tribal governments or the private sector. Therefore, this action is not 

subject to the requirements of sections 202 or 205 of the UMRA.

This action is also not subject to the requirements of section 203 of UMRA 

because it contains no regulatory requirements that might significantly or uniquely affect 

small governments. 

F. Executive Order 13132: Federalism

This action does not have federalism implications. It will not have substantial 

direct effects on the States, on the relationship between the national government and the 

States, or on the distribution of power and responsibilities among the various levels of 

government, as specified in Executive Order 13132. This direct final rule merely corrects

and clarifies regulatory provisions. Thus, Executive Order 13132 does not apply to this 

action. 

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

Governments

This action does not have tribal implications, as specified in Executive Order 
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13175 (65 FR 67249, November 9, 2000). This direct final rule merely corrects and 

clarifies regulatory provisions. Tribal governments would be affected only to the extent 

they purchase and use regulated vehicles. Thus, Executive Order 13175 does not apply to 

this action.

H. Executive Order 13045: Protection of Children from Environmental Health and 

Safety Risks

This action is not subject to Executive Order 13045 (62 FR 19885, April 23, 

1997) because it is not economically significant as defined in Executive Order 12866, and 

because EPA and NHTSA do not believe the environmental health or safety risks 

addressed by this action present a disproportionate risk to children. This direct final rule 

merely corrects and clarifies regulatory provisions. 

I. Executive Order 13211: Actions that Significantly Affect Energy Supply, 

Distribution, or Use

This action is not subject to Executive Order 13211 (66 FR 28355, May 22, 

2001), because it is not likely to have a significant adverse effect on the supply, 

distribution, or use of energy. This direct final rule merely corrects and clarifies 

regulatory provisions. 

J. National Technology Transfer Advancement Act

Section 12(d) of the National Technology Transfer and Advancement Act of 1995 

(“NTTAA”), Public Law No. 104-113, 12(d) (15 U.S.C. 272 note) directs EPA to use 
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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 agencies to provide Congress, through OMB, explanations when 

the Agency decides not to use available and applicable voluntary consensus standards. 

This action slightly expands the use of voluntary consensus standards by adding a 

reference standard under 40 CFR 1048.105. Other amendments in this direct final rule do 

not involve application of new technical standards. However, the underlying regulations 

in many cases rely on voluntary consensus standards. For example, EPA and NHTSA 

included several voluntary consensus standards in the development of the Greenhouse 

Gas Emissions Standards and Fuel Efficiency Standards for Medium- and Heavy-Duty 

Engines and Vehicles (76 FR 57106, September 15, 2011).

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

Minority Populations and Low-Income Populations

Executive Order 12898 (59 FR 7629, February 16, 1994) establishes federal 

executive policy on environmental justice. Its main provision directs federal agencies, to 

the greatest extent practicable and permitted by law, to make environmental justice part 

of their mission by identifying and addressing, as appropriate, disproportionately high 

and adverse human health or environmental effects of their programs, policies, and 

activities on minority populations and low-income populations in the United States. 
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EPA and NHTSA have determined that this rule will not have disproportionately 

high and adverse human health or environmental effects on minority or low-income 

populations because it merely corrects provisions for manufacturers to use to demonstrate 

compliance of heavy-duty engines and vehicles. 

L. Congressional Review Act

The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the Small 

Business Regulatory Enforcement Fairness Act of 1996, generally provides that before a 

rule may take effect, the agency promulgating the rule must submit a rule report, which 

includes a copy of the rule, to each House of the Congress and to the Comptroller 

General of the United States. EPA and NHTSA will submit reports containing this rule 

and other required information to the U.S. Senate, the U.S. House of Representatives, and 

the Comptroller General of the United States prior to publication of the rule in the 

Federal Register. A Major rule cannot take effect until 60 days after it is published in the 

Federal Register. This action is not a “major rule” as defined by 5 U.S.C. 804(2). This 

rule will be effective on [Insert date 60 days from date of publication in the Federal 

Register].

M. Executive Order 12988 (Civil Justice Reform)

This final rule meets applicable standards in sections 3(a) and 3(b)(2) of 

Executive Order 12988, Civil Justice Reform, to minimize litigation, eliminate 

ambiguity, and reduce burden.
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V. Statutory Authority

A. EPA

Statutory authority for the vehicle controls is found in Clean Air Act section 

202(a) (which authorizes standards for emissions of pollutants from new motor vehicles 

which emissions cause or contribute to air pollution which may reasonably be anticipated 

to endanger public health or welfare), sections 202(d), 203-209, 216, and 301 (42 U.S.C. 

7521 (a), 7521 (d), 7522, 7523, 7524, 7525, 7541, 7542, 7543, 7550, and 7601).

B. NHTSA

Statutory authority for the fuel consumption standards is found in section 103 

(which authorizes a fuel efficiency improvement program, designed to achieve the 

maximum feasible improvement to be created for commercial medium- and heavy-duty 

on-highway vehicles and work trucks, to include appropriate test methods, measurement 

metrics, standards, and compliance and enforcement protocols that are appropriate, costeffective and technologically feasible) of the Energy Independence and Security Act of 

2007, 49 U.S.C. 32902(k).

List of Subjects

40 CFR Part 85

Confidential business information, Imports, Labeling, Motor vehicle pollution, Reporting 

and recordkeeping requirements, Research, Warranties.

40 CFR Part 86
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Administrative practice and procedure, Confidential business information, Labeling, 

Motor vehicle pollution, Reporting and recordkeeping requirements.

40 CFR Part 1036

Administrative practice and procedure, Air pollution control, Confidential business 

information, Environmental protection, Labeling, Motor vehicle pollution, Reporting and 

recordkeeping requirements, Warranties.

40 CFR Part 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 Part 1039

Environmental protection, Administrative practice and procedure, Air pollution control, 

Confidential business information, Imports, Labeling, Penalties, Reporting and 

recordkeeping requirements, Warranties.

40 CFR Part 1042

Environmental protection, Administrative practice and procedure, Air pollution control, 

Confidential business information, Imports, Labeling, Penalties, Vessels, Reporting and 

recordkeeping requirements, Warranties. 
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40 CFR Part 1048

Environmental protection, Administrative practice and procedure, Air pollution control, 

Confidential business information, Imports, Incorporation by reference, Labeling, 

Penalties, Reporting and recordkeeping requirements, Warranties.

40 CFR Part 1054

Environmental protection, Administrative practice and procedure, Air pollution control, 

Confidential business information, Imports, Labeling, Penalties, Reporting and 

recordkeeping requirements, Warranties.

40 CFR Part 1065 and 1066

Administrative practice and procedure, Air pollution control, Reporting and 

recordkeeping requirements, Research.

40 CFR Part 1068

Environmental protection, Administrative practice and procedure, Confidential business 

information, Imports, Motor vehicle pollution, Penalties, Reporting and recordkeeping 

requirements, Warranties.

49 CFR Parts 523 and 535

Fuel economy.
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For the reasons set forth in the preamble, the Environmental Protection Agency is

amending title 40, chapter I of the Code of Federal Regulations as follows: 

PART 85—CONTROL OF AIR POLLUTION FROM MOBILE SOURCES

1. The authority citation for part 85 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart F—[Amended]

2. Section 85.525 is amended by revising paragraph (a)(2)(i) introductory text and 

adding paragraph (a)(2)(iii) to read as follows:

§ 85.525 Applicable standards.

* * * * *

(a) * * *

(2) * * *

(i) Subject to the following exceptions and special provisions, compliance with light-duty 

vehicle greenhouse gas emission standards is demonstrated by complying with the N2O

and CH4 standards and provisions set forth in 40 CFR 86.1818–12(f)(1) and the in-use 

CO2 exhaust emission standard set forth in 40 CFR 86.1818–12(d) as determined by the 

OEM for the subconfiguration that is identical to the fuel conversion emission data 

vehicle (EDV):

* * * * *

(iii) Subject to the following exceptions and special provisions, compliance with 

greenhouse gas emission standards for heavy-duty vehicles subject to 40 CFR 1037.104
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is demonstrated by complying with the N2O and CH4 standards and provisions set forth in 

40 CFR 1037.104 and the in-use CO2 exhaust emission standard set forth in 40 CFR 

1037.104(b) as determined by the OEM for the subconfiguration that is identical to the 

fuel conversion emission data vehicle (EDV):

(A) If the OEM complied with alternate standards for N2O and/or CH4, as allowed under 

40 CFR 1037.104(c) you may demonstrate compliance with the same alternate standards.

(B) If you are unable to meet either the N2O or CH4 standards and your fuel conversion 

CO2 measured value is lower than the in-use CO2 exhaust emission standard, you may 

also convert the difference between the in-use CO2 exhaust emission standard and the 

fuel conversion CO2 measured value into GHG equivalents of CH4 and/or N2O, using 298 

g CO2 to represent 1 g N2O, and 25 g CO2 to represent 1 g CH4. You may then subtract 

the applicable converted values from the fuel conversion measured values of CH4 and/ or 

N2O to demonstrate compliance with the CH4 and/or N2O standards.

(C) You may alternatively comply with the greenhouse gas emission requirements by 

comparing emissions from the vehicle before and after the fuel conversion. This 

comparison must be based on FTP test result from the emission data vehicle (EDV) 

representing the pre-conversion test group. The sum of CO2, CH4, and N2O shall be 

calculated for pre- and post-conversion FTP test results, where CH4 and N2O are 

weighted by their global warming potentials of 25 and 298, respectively. The postconversion sum of these emissions must be lower than the pre-conversion greenhouse gas 

emission result. Calculate CO2 emissions as specified in 40 CFR 600.113. If we waive 
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N2O measurement requirements based on a statement of compliance, disregard N2O for 

all measurements and calculations under this paragraph (a)(2)(iii)(C).

* * * * *

PART 86 – CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY 

VEHICLES AND ENGINES

3. The authority citation for part 86 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart A—[Amended]

§ 86.007-23---[Amended]

4. Section 86.007-23 is amended by removing paragraph (n).

5. Section 86.010-18 is amended by adding paragraph (q)(6) to read as follows:

§ 86.010-18 On-board Diagnostics for engines used in applications greater than 

14,000 pounds GVWR.

* * * * *

(q) * * *

(6) Manufacturers that modify the engine's diagnostic system from the approved 

configuration to be compatible with a hybrid powertrain system under this paragraph (q)

must add the following compliance statement to the ECI label: "for use in hybrid 

applications only".
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Subpart S—[Amended]

§ 86.1844-01---[Amended]

6. Section 86.1844-01 is amended by removing paragraph (j).

7. Section 86.1865-12 is amended by revising paragraphs (a)(1) introductory text, 

(a)(1)(ii), (j)(4)(i), (k)(4) introductory text, (k)(8)(iv)(A), (l)(1)(i) introductory text, 

(l)(1)(ii) introductory text, and (l)(3) to read as follows:

§ 86.1865-12 How to comply with the fleet average CO2 standards.

(a) * * *

(1) Unless otherwise exempted under the provisions of § 86.1801-12(j) or (k), CO2 fleet 

average exhaust emission standards of this subpart apply to:

* * * * *

(ii) Heavy-duty vehicles subject to standards under 40 CFR 1037.104. 

* * * * *

(j) * * *

(4) * * *

(i) Manufacturers must report in their annual reports to the Agency that they met the 

relevant corporate average standard by showing that their production-weighted average 

CO2 emission levels of passenger automobiles, light trucks, and heavy-duty vehicles, as 

applicable, are at or below the applicable fleet average standards; or
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* * * * *

(k) * * *

(4) Credits are earned on the last day of the model year. Manufacturers must calculate, 

for a given model year and separately for passenger automobiles, light trucks, and heavyduty vehicles (as specified in 40 CFR 1037.104), the number of credits or debits it has 

generated according to the following equation rounded to the nearest megagram:

* * * * *

(8) * * *

(iv) * * *

(A) If a manufacturer ceases production of passenger automobiles, light trucks, or heavyduty vehicles subject to the standards of 40 CFR 1037.104, the manufacturer continues to 

be responsible for offsetting any debits outstanding within the required time period. Any 

failure to offset the debits will be considered a violation of paragraph (k)(8)(i) of this 

section and may subject the manufacturer to an enforcement action for sale of vehicles 

not covered by a certificate, pursuant to paragraphs (k)(8)(ii) and (iii) of this section.

* * * * *

(l) * * *

(1) * * *

(i) Manufacturers producing any light-duty vehicles, light-duty trucks, or medium-duty 

passenger vehicles subject to the provisions in this subpart or any heavy-duty vehicles 

subject to the standards of 40 CFR 1037.104 must establish, maintain, and retain all the 

following information in adequately organized records for each model year: 
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* * * * *

(ii) Manufacturers producing any passenger automobiles or light trucks subject to the 

provisions in this subpart and vehicles subject to the standards of 40 CFR 1037.104 must 

establish, maintain, and retain all the following information in adequately organized 

records for each passenger automobile or light truck subject to this subpart:

* * * * *

(3) Notice of opportunity for hearing. Any voiding of the certificate under paragraph 

(l)(1)(vi) of this section will be made only after EPA has offered the affected 

manufacturer an opportunity for a hearing conducted in accordance with § 86.614 and, if 

a manufacturer requests such a hearing, will be made only after an initial decision by the 

Presiding Officer.

PART 1036--CONTROL OF EMISSIONS FROM NEW AND IN-USE HEAVYDUTY HIGHWAY ENGINES

8. The authority citation for part 1036 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart A—[Amended]

9. Section 1036.5 is amended by revising paragraph (b) to read as follows:

§ 1036.5 Which engines are excluded from this part’s requirements?

* * * * *
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(b) Engines installed in heavy-duty vehicles that do not provide motive power are 

nonroad engines. The provisions of this part therefore do not apply to these engines. See 

40 CFR part 1039, 1048, or 1054 for other requirements that apply for these auxiliary 

engines. See 40 CFR part 1037 for requirements that may apply for vehicles using these 

engines.

* * * * *

Subpart B—[Amended]

10. Section 1036.150 is amended by revising paragraphs (d), (g)(2), and (g)(3) to read as 

follows:

§ 1036.150 Interim provisions.

* * * * *

(d) Small manufacturers. Manufacturers meeting the small business criteria specified for 

“Gasoline Engine and Engine Parts Manufacturing” or “Other Engine Equipment 

Manufacturers” in 13 CFR 121.201 are not subject to the greenhouse gas emission 

standards in § 1036.108. Qualifying manufacturers must notify the Designated 

Compliance Officer before importing or introducing into U.S. commerce excluded 

engines. This notification must include a description of the manufacturer’s qualification 

as a small business under 13 CFR 121.201. You must label your excluded engines with 

the statement: “THIS ENGINE IS EXCLUDED UNDER 40 CFR 1036.150(d).” 

* * * * *
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(g) * * *

(2) You may use an assigned additive DF of 0.020 g/hp-hr for N2O emissions from 

any engine. 

(3) You may use an assigned additive DF of 0.020 g/hp-hr for CH4 emissions from 

any engine.

* * * * *

Subpart C—[Amended]

11. Section 1036.205 is amended by revising paragraph (e) to read as follows:

§ 1036.205 What must I include in my application?

* * * * *

(e) Identify the CO2 FCLs with which you are certifying engines in the engine family; 

also identify any FELs that apply for CH4 and N2O. The actual U.S.-directed production 

volume of configurations that have CO2 emission rates at or below the FCL and CH4 and 

N2O emission rates at or below the applicable standards or FELs must be at least one 

percent of your actual (not projected) U.S.-directed production volume for the engine 

family. Identify configurations within the family that have emission rates at or below the 

FCL and meet the one percent requirement. For example, if your U.S.-directed 

production volume for the engine family is 10,583 and the U.S.-directed production 

volume for the tested rating is 75 engines, then you can comply with this provision by 

setting your FCL so that one more rating with a U.S.-directed production volume of at 
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least 31 engines meets the FCL. Where applicable, also identify other testable 

configurations required under § 1036.230(b)(2).

* * * * *

12. Section 1036.225 is amended by revising paragraph (f) introductory text to read as 

follows:

§ 1036.225 Amending my application for certification.

* * * * *

(f) You may ask us to approve a change to your FEL in certain cases after the start of 

production, but before the end of the model year. If you change an FEL for CO2, your 

FCL for CO2 is automatically set to your new FEL divided by 1.03. The changed FEL

may not apply to engines you have already introduced into U.S. commerce, except as 

described in this paragraph (f). You may ask us to approve a change to your FEL in the 

following cases:

* * * * *

Subpart F—[Amended]

13. Section 1036.525 is amended by revising paragraph (a) to read as follows:

§ 1036.525 Hybrid engines. 

(a) If your engine system includes features that recover and store energy during engine 

motoring operation test the engine as described in paragraph (d) of this section. For 
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purposes of this section, features that recover energy between the engine and 

transmission are considered related to engine motoring.

* * * * *

Subpart G—[Amended]

14. Section 1036.615 is amended by revising paragraphs (a) and (c) to read as follows:

§ 1036.615 Engines with Rankine cycle waste heat recovery and hybrid powertrains.

* * * * *

(a) Pre-transmission hybrid powertrains. Test pre-transmission hybrid powertrains with 

the hybrid engine test procedures of 40 CFR part 1065 or with the post-transmission test 

procedures in 40 CFR 1037.550. Pre-transmission hybrid powertrains are those engine 

systems that include features to recover and store energy during engine motoring 

operation but not from the vehicle’s wheels.

* * * * *

(c) Calculating credits. Calculate credits as specified in subpart H of this part. Credits 

generated from engines and powertrains certified under this section may be used in other 

averaging sets as described in § 1036.740(c).

* * * * *

Subpart I—[Amended]

15. Section 1036.801 is amended by adding a definition for “Preliminary approval” in 
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alphabetical order to read as follows:

§ 1036.801 Definitions.

* * * * *

Preliminary approval means approval granted by an authorized EPA representative prior 

to submission of an application for certification, consistent with the provisions of § 

1036.210.

* * * * *

PART 1037—CONTROL OF EMISSIONS FROM NEW HEAVY-DUTY MOTOR 

VEHICLES 

16. The authority citation for part 1037 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart A—[Amended]

17. Section 1037.15 is amended by revising paragraph (c) to read as follows:

§ 1037.15 Do any other regulation parts apply to me?

* * * * *

(c) Part 86 of this chapter applies for certain vehicles as specified in this part. For 

example, the test procedures and most of part 86, subpart S, apply for vehicles subject to 

§ 1037.104; including the following paragraphs of 40 CFR 86.1865-12 apply: (a), (h)(1), 
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(h)(3), (j)(1), (j)(4), (k)(1) through (4), (k)(7)(ii), (k)(8), (k)(9), (l)(1), (l)(2)(i), (l)(2)(ii), 

(l)(2)(vi) through (viii), and (l)(3).

* * * * *

Subpart B—[Amended]

18. Section 1037.104 is amended by revising paragraphs (a)(2) introductory text, (d)(2), 

(d)(4), (d)(6), (d)(9), (d)(12), (d)(13), and (g) and adding paragraph (d)(15) 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.

* * * * *

(a) * * *

(2) Using the appropriate work factor, calculate a target value for each vehicle 

subconfiguration (or group of subconfigurations allowed under paragraph (a)(4) of this 

section) you produce using one of the following equations, or the phase-in provisions in §

1037.150(b), rounding to the nearest 0.1 g/ mile:

* * * * *

(d) * * *

(2) The following general credit provisions apply:

(i) Credits you generate under this section may be used only to offset credit deficits under 

this section. You may bank credits for use in a future model year in which your average 
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CO2 level exceeds the standard. You may trade credits to another manufacturer 

according to 40 CFR 86.1865-12(k)(8). Before you bank or trade credits, you must apply 

any available credits to offset a deficit if the deadline to offset that credit deficit has not 

yet passed. 

(ii) Vehicles subject to the standards of this section are included in a single greenhouse 

gas averaging set separate from any averaging set otherwise included in 40 CFR part 86. 

(iii) Banked CO2 credits keep their full value for five model years after the year in which 

they were generated. Unused credits expire at the end of this fifth model year.

* * * * *

(4) The CO2, N2O, and CH4 standards apply for a weighted average of the city (55%) and 

highway (45%) test cycle results. Note that this differs from the way the criteria pollutant 

standards apply for heavy-duty vehicles.

* * *

(6) Credits are calculated using the useful life value (in miles) in place of “vehicle 

lifetime miles” specified in 40 CFR part 86, subpart S. Calculate a total credit or debit

balance in a model year by adding credits and debits from 40 CFR 86.1865-12(k)(4),

subtracting any CO2-equivalent debits for N2O or CH4 calculated according to 

§1037.104(c), and adding any of the following credits:

(i) Advanced technology credits according to paragraph (d)(7) of this section and § 

1037.150(i).

(ii) Innovative technology credits according to paragraph (d)(13) of this section.

(iii) Early credits according to § 1037.150(a)(2).
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* * * * *

(9) Calculate your fleet-average emission rate consistent with good engineering 

judgment and the provisions of 40 CFR 86.1865. The following additional provisions 

apply:

(i) Unless we approve a lower number, you must test at least ten subconfigurations. 

If you produce more than 100 subconfigurations in a given model year, you must test 

at least 25 subconfigurations or ten percent of your subconfigurations (whichever is 

less). For purposes of this paragraph (d)(9)(i), count carryover tests, but do not 

include analytically derived CO2 emission rates, data substitutions, or other untested 

allowances. We may approve a lower number of tests for manufacturers that have 

limited product offerings or low sales volumes. Note that good engineering judgment 

and other provisions of this part may require you to test more subconfigurations than 

these minimum values.

(ii) The provisions of paragraph (g) of this section specify how you may use 

analytically derived CO2 emission rates.

(iii) All final production volume at the subconfiguration level must be represented by 

test data (real, data substituted, or analytical).

(iv) Perform fleet-average CO2 calculations as described in 40 CFR 86.1865 and 40 

CFR part 600, with the following exceptions:

(A) Use CO2 emissions values for all test results, intermediate calculations, and 

fleet average calculations instead of the carbon-related exhaust emission (CREE) 

values specified in 40 CFR parts 86 and 600.
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(B) Perform intermediate CO2 calculations for subconfigurations within each 

configuration using the subconfiguration and configuration definitions in 

paragraph (d)(12) of this section.

(C) Perform intermediate CO2 calculations for configurations within each test 

group and transmission type (instead of configurations within each base level and 

base levels within each model type). Use the configuration definition in 

paragraph (d)(12)(i) of this section.

(D) Do not perform intermediate CO2 calculations for each base level or for each 

model type. Base level and model type CO2 calculations are not applicable to 

heavy-duty vehicles subject to standards in this section. 

(E) Determine fleet average CO2 emissions for heavy-duty vehicles subject to 

standards in this section as described in 40 CFR 600.510-12(j), except that the 

calculations must be performed on the basis of test group and transmission type 

(instead of the model-type basis specified in the light-duty vehicle regulations), 

and the calculations for dual fuel, multi-fuel, and flexible fuel vehicles must be 

consistent with the provisions of paragraph (d)(10)(i) of this section.

* * * * *

(12) The following definitions apply for the purposes of this section:

(i) Configuration means a subclassification within a test group based on engine code, 

transmission type and gear ratios, final drive ratio, and other parameters we designate. 

Transmission type means the basic type of the transmission (e.g., automatic, manual, 

automated manual, semi-automatic, or continuously variable) and does not include 
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the drive system of the vehicle (e.g., front-wheel drive, rear-wheel drive, or fourwheel drive). Engine code means the combination of both “engine code” and “basic 

engine” as defined in 40 CFR 600.002. Note that this definition differs from the one 

in 40 CFR 86.1803. 

(ii) Subconfiguration means a unique combination within a vehicle configuration (as 

defined in this paragraph (d)(12)) of equivalent test weight, road-load horsepower, 

and any other operational characteristics or parameters that we determine may 

significantly affect CO2 emissions within a vehicle configuration. Note that for 

vehicles subject to standards of this section, equivalent test weight (ETW) is based on 

the ALVW of the vehicle as outlined in paragraph (d)(11) of this section.

(iii) The terms “complete vehicle” and “incomplete vehicle” have the meanings given 

for “complete heavy-duty vehicle” and “incomplete heavy-duty vehicle”, 

respectively, in 40 CFR 86.1803.

(13) This paragraph (d)(13) applies for CO2 reductions resulting from technologies that 

were not in common use before 2010 that are not reflected in the specified test 

procedures. We may allow you to generate emission credits consistent with the 

provisions of 40 CFR 86.1869-12(c) and (d). You do not need to provide justification for 

not using the 5-cycle methodology.

* * * * *

(15) You must submit a final report within 90 days after the end of the model year. 

Unless we specify otherwise, include applicable information identified in 40 CFR 
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86.1865-12(l), 40 CFR 600.512, and 49 CFR 535.8(e). The final report must include at 

least the following information:

(i) Model year.

(ii) Applicable fleet-average CO2 standard.

(iii) Calculated fleet-average CO2 value and all the values required to calculate the 

CO2 value.

(iv) Number of credits or debits incurred and all values required to calculate those 

values.

(v) Resulting balance of credits or debits.

(vi) N2O emissions.

(vii) CH4 emissions.

(viii) HFC leakage score.

* * * * *

(g) Analytically derived CO2 emission rates (ADCs). This paragraph (g) describes an 

allowance to use estimated (i.e., analytically derived) CO2 emission rates based on baseline 

test data instead of measured emission rates for calculating fleet-average emissions. Note that 

these ADCs are similar to ADFEs used for light-duty vehicles. Note also that F terms used in 

this paragraph (g) represent coefficients from the following road load equation:

(1) Except as specified in paragraph (g)(2) of this section, use the following equation to 

calculate the ADC of a new vehicle from road load force coefficients (F0, F1, F2), axle ratio, 

and test weight :
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Where: 

ADC = Analytically derived combined city/highway CO2 emission rate (g/mile) for a new 

vehicle. 

CO2base= Combined city/highway CO2 emission rate (g/mile) of a baseline vehicle. 

ΔF0 = F0 of the new vehicle – F0 of the baseline vehicle.

ΔF1 = F1 of the new vehicle – F1 of the baseline vehicle. 

ΔF2 = F2 of the new vehicle – F2 of the baseline vehicle. 

ΔAR = Axle ratio of the new vehicle – axle ratio of the baseline vehicle. 

ΔETW = ETW of the new vehicle – ETW of the baseline vehicle.

(2) The purpose of this section is to accurately estimate CO2 emission rates.

(i) You must apply the provisions of this section consistent with good engineering 

judgment. For example, do not use the equation in paragraph (g)(1) of this section 

where good engineering judgment indicates that it will not accurately estimate 

emissions. You may ask us to approve alternate equations that allow you to estimate 

emissions more accurately. 

(ii) The analytically derived CO2 equation in paragraph (g)(1) of this section may be 

periodically updated through publication of an EPA guidance document to more 

accurately characterize CO2 emission levels’ for example, changes may be 

appropriate based on new test data, future technology changes, or to changes in future 

CO2 emission levels. Any EPA guidance document will determine the model year 
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that the updated equation takes effect. We will issue guidance no later than eight 

months before the effective model year. For example, for 2014 models, the model 

year may start January 2, 2013, so guidance would be issued by May 1, 2012 for 

model year 2014. 

(3) You may select, without our advance approval, baseline test data if they meet all the 

following criteria: 

(i) Vehicles considered for the baseline test must comply with all applicable emission 

standards in the model year associated with the ADC. 

(ii) You must include in the pool of tests considered for baseline selection all official 

tests of the same or equivalent basic engine, transmission class, engine code, 

transmission code, engine horsepower, dynamometer drive wheels, and compression 

ratio as the ADC subconfiguration. Do not include tests in which emissions exceed 

any applicable standard.

(iii) Where necessary to minimize the CO2 adjustment, you may supplement the pool 

with tests associated with worst-case engine or transmission codes and carryover or 

carry-across engine families. If you do, all the data that qualify for inclusion using the 

elected worst-case substitution (or carryover or carry-across) must be included in the 

pool as supplemental data (i.e., individual test vehicles may not be selected for 

inclusion). You must also include the supplemental data in all subsequent pools, 

where applicable. 
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(iv) Except with our advance approval, tests previously used during the subject model 

year as baseline tests in 20 other ADC subconfigurations must be eliminated from the 

pool. 

(v) Select the tested subconfiguration with the smallest absolute difference between 

the ADC and the test CO2 emission rate for combined emissions. Use this as the 

baseline test for the target ADC subconfiguration. 

(4) You may ask us to allow you to use baseline test data not fully meeting the provisions 

of paragraph (g)(3) of this section. 

(5) Calculate the ADC rounded to the nearest 0.1 g/mile. Except with our advance

approval, the downward adjustment of ADC from the baseline is limited to ADC values 

20 percent below the baseline emission rate. The upward adjustment is not limited. 

(6) You may not submit an ADC if an actual test has been run on the target 

subconfiguration during the certification process or on a development vehicle that is 

eligible to be declared as an emission-data vehicle.

(7) [Reserved]

(8) Keep the following records for at least five years, and show them to us if we ask to see 

them:

(i) The pool of tests.

(ii) The vehicle description and tests chosen as the baseline and the basis for the selection.

(iii) The target ADC subconfiguration.

(iv) The calculated emission rates. 
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(9) We may perform or order a confirmatory test of any subconfiguration covered by an 

ADC. 

(10) Where we determine that you did not fully comply with the provisions of this paragraph 

(g), we may require that you comply based on actual test data and that you recalculate your 

fleet-average emission rate.

* * * * *

19. Section 1037.115 is amended by revising paragraph (c) introductory text and 

removing and reserving paragraph (c)(2) to read as follows:

§ 1037.115 Other requirements. 

* * * * *

(c) Air conditioning leakage. Loss of refrigerant from your air conditioning systems 

may not exceed 1.50 percent per year, except as allowed by paragraph (c)(3) of this 

section. Calculate the total leakage rate in g/year as specified in 40 CFR 86.1867-12(a). 

Calculate the percent leakage rate as: [total leakage rate (g/yr)] ÷ [total refrigerant 

capacity (g)] × 100. Round your leakage rate to the nearest one-hundredth of a percent. 

See § 1037.150 for vocational vehicles.

* * * * *

20. Section 1037.135 is amended by revising paragraphs (c)(5) and (c)(9) to read as 

follows:

§ 1037.135 Labeling
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* * * * *

(c) * * *

(5) State the date of manufacture [DAY (optional), MONTH, and YEAR]. You may omit 

this from the label if you stamp, engrave, or otherwise permanently identify it elsewhere 

on the vehicle, in which case you must also describe in your application for certification 

where you will identify the date on the vehicle.

* * * *

(9) Include the following statement for vehicles with an evaporative canister for 

controlling diurnal emissions: “THIS VEHICLE IS DESIGNED TO COMPLY WITH 

EVAPORATIVE EMISSION STANDARDS WITH UP TO x GALLONS OF FUEL 

TANK CAPACITY.” Complete this statement by identifying the maximum specified fuel 

tank capacity associated with your certification.

* * * * *

21. Section 1037.150 is amended by revising paragraphs (a)(2), (l) introductory text, and 

(l)(1) to read as follows:

§ 1037.150 Interim provisions.

* * * * *

(a) * * *

(2) This paragraph (a)(2) applies for regulatory sub-categories subject to the standards of 

§ 1037.104. To generate early credits under this paragraph (a)(2) for any vehicles other 
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than electric vehicles, you must certify your entire U.S.-directed fleet to these standards. 

If you calculate a separate fleet average for advanced-technology vehicles under §

1037.104(c)(7), you must certify your entire U.S.-directed production volume of both 

advanced and conventional vehicles within the fleet. Except as specified in paragraph

(a)(4) of this section, if some test groups are certified after the start of the model year, 

you may generate credits only for production that occurs after all test groups are certified. 

For example, if you produce three test groups in an averaging set and you receive your 

certificates for those test groups on January 4, 2013, March 15, 2013, and April 24, 2013, 

you may not generate credits for model year 2013 for vehicles from any of the test groups 

produced before April 24, 2013. Calculate credits relative to the standard that would 

apply in model year 2014 using the applicable equations in 40 CFR part 86 and your 

model year 2013 U.S.-directed production volumes. These credits may be used to show 

compliance with the standards of this part for 2014 and later model years. We 

recommend that you notify us of your intent to use this provision before submitting your 

applications.

* * * * *

(l) Optional certification under § 1037.104. You may certify certain complete or cabcomplete vehicles to the standards of § 1037.104. All vehicles optionally certified under 

this paragraph (l) are deemed to be subject to the standards of § 1037.104. Note that for 

vehicles above 14,000 pounds GVWR and at or below 26,000 pounds GVWR, 

certification under this paragraph (l) does not affect how you may or may not certify with 

respect to criteria pollutants. For example, certifying a Class 4 vehicle under this 
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paragraph (l) does not allow you to chassis-certify these vehicles with respect to criteria 

pollutants.

(1) You may certify any complete or cab-complete spark-ignition vehicles above 14,000 

pounds GVWR and at or below 26,000 pounds GVWR to the standards of § 1037.104

even though § 1037.104 specifies that you may certify vehicles to the standards of that 

section only if they are chassis-certified for criteria pollutants. 

* * * * *

Subpart C—[Amended]

22. Section 1037.201 is amended by revising paragraph (g) to read as follows:

§ 1037.201 General requirements for obtaining a certificate of conformity.

* * * * *

(g) We may perform confirmatory testing on your vehicles; for example, we may test 

vehicles to verify drag areas or other GEM inputs. This includes vehicles used to 

determine Falt-aero under § 1037.521. We may require you to deliver your test vehicles to 

a facility we designate for our testing. Alternatively, you may choose to deliver another 

vehicle that is identical in all material respects to the test vehicle. Where certification is 

based on testing components such as tires, we may require you to deliver test components 

to a facility we designate for our testing. 

23. Section 1037.230 is amended by revising paragraph (a)(1)(xiii) and adding paragraph 
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(a)(1)(xiv) to read as follows:

§ 1037.230 Vehicle families, sub-families, and configurations.

(a) * * *

(1) * * *

(xiii) Vocational tractors above 26,000 pounds GVWR and at or below 33,000 pounds 

GVWR. Note that vocational tractor provisions do not apply for vehicles at or below 

26,000 pounds GVWR. 

(xiv) Vocational tractors above 33,000 pounds GVWR.

* * * * *

Subpart F—[Amended]

24. Section 1037.501 is amended by revising paragraph (g)(1)(iv) to read as follows:

§ 1037.501 General testing and modeling provisions.

* * * * *

(g) * * *

(1) * * *

(iv) It includes dual 22.5 inch wheels, standard mudflaps, and standard landing gear. The 

centerline of the rear tandem axle must be 146 +/- 4 inches from the rear of the trailer.

* * * * *

25. Section 1037.520 is amended by revising the section heading, the introductory text, 
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Table 1 in paragraph (b)(2), and paragraph (e)(1) before the table to read as follows:

§ 1037.520 Modeling CO2 emissions to show compliance.

This section describes how to use the Greenhouse gas Emissions Model (GEM) 

simulation tool (incorporated by reference in § 1037.810) to show compliance with the 

CO2 standards of §§ 1037.105 and 1037.106. Use good engineering judgment when 

demonstrating compliance using the GEM.

* * * * *

(b) * * *

(2) * * *

Table 1 to § 1037.520—High-Roof Day and Sleeper Cabs

High-Roof Day Cabs

Bin Level If your measured CDA 

(m2) is . . . 

Then your CD input is . . .

Bin I ≥ 8.0 0.79

Bin II 7.1-7.9 0.72

Bin III 6.2-7.0 0.63

Bin IV 5.6-6.1 0.56

Bin V ≤ 5.5 0.51

High-Roof Sleeper Cabs

Bin Level If your measured CDA 

(m2) is . . .

Then your CD input is . . .

Bin I ≥ 7.6 0.75

Bin II 6.8-7.5 0.68

Bin III 6.3-6.7 0.60

Bin IV 5.6-6.2 0.52

Bin V ≤5.5 0.47

* * * * *

(e) * * *
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(1) Vehicle weight reduction inputs for wheels are specified relative to dual-wide tires 

with conventional steel wheels. For purposes of this paragraph (e)(1), a light-weight 

aluminum wheel is one that weighs at least 21 pounds less than a comparable 

conventional steel wheel. The inputs are listed in Table 3 to this section. For example, a 

tractor with aluminum steer wheels and eight (4x2) dual-wide aluminum drive wheels

would have an input of 210 pounds (2x21 + 8x21). 

* * * * *

26. Section 1037.525 is amended by revising the introductory text to read as follows:

§ 1037.525 Special procedures for testing hybrid vehicles with power take-off. 

This section describes the procedure for quantifying the reduction in greenhouse gas 

emissions as a result of running power take-off (PTO) devices with a hybrid powertrain. 

The procedures are written to test the PTO by ensuring that the engine produces all of the 

energy with no net change in stored energy. The full test for the hybrid vehicle is from a 

fully charged renewable energy storage system (RESS) to a depleted RESS and then back 

to a fully charged RESS. These procedures may be used for testing any hybrid 

architecture for which you are requesting a vehicle certificate using either chassis testing 

or powertrain testing. You must include all hardware for the PTO system. You may ask 

us to modify the provisions of this section to allow testing hybrid vehicles other than 

electric-battery hybrids, consistent with good engineering judgment.

* * * * *
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27. Section 1037.550 is amended by revising the section heading, the introductory text, 

and paragraphs (d) through (g) to read as follows:

§ 1037.550 Special procedures for testing hybrid systems. 

This section describes the procedure for simulating a chassis test with a pre-transmission 

or post-transmission hybrid system for A to B testing. These procedures may also be 

used to perform A to B testing with non-hybrid systems.

* * * * *

(d) Calculate the transmission output shaft’s angular speed target for the driver model, 

fnref,driver, from the linear speed associated with the vehicle cycle using the following 

equation:

d

nrefi,driver 2

cyclei v k

f

r

Where:

vcyclei = vehicle speed of the test cycle for each point, i, starting from i=1.

kd = final drive ratio (the angular speed of the transmission output shaft divided by the 

angular speed of the drive axle), as declared by the manufacturer.

r = radius of the loaded tires, as declared by the manufacturer.

(e) Use speed control with a loop rate of at least 100 Hz to program the dynamometer to 

follow the test cycle, as follows: 

(1) Calculate the transmission output shaft’s angular speed target for the 

dynamometer, fnref,dyno, from the measured linear speed at the dynamometer rolls 

using the following equation:
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refi d

nrefi,dyno 2

v k f

r

Where:

d i-1 2 i i-1

refi ref,i-1 ref,i-1 brake,i-1 ref,i-1

k T t t v A B v C v F v

r M

T = instantaneous measured torque at the transmission output shaft.

Fbrake = instantaneous brake force applied by the driver model to add force to slow 

down the vehicle.

t = elapsed time in the driving schedule as measured by the dynamometer, in seconds. 

(2) For each test, validate the measured transmission output shaft’s speed with the 

corresponding reference values according to 40 CFR 1065.514(e). You may delete 

points when the vehicle is stopped. Perform the validation based on speed values at 

the transmission output shaft. For steady-state tests (55 mph and 65 mph cruise), 

apply cycle-validation criteria by treating the sampling periods from the two tests as a 

continuous sampling period. Perform this validation based on the following 

parameters:

Table 1 of § 1037.550 – Statistical criteria for validating duty cycles

Parameter Speed Control

Slope, a1 0.950 < a1 < 1.030

Absolute value of intercept, |a0| < 2.0 % of maximum test speed

Standard error of estimate, SEE < 5 % of maximum test speed

Coefficient of determination, r

2

> 0.970
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(f) Send a brake signal when throttle position is equal to zero and vehicle speed is greater 

than the reference vehicle speed from the test cycle. Set a delay before changing the 

brake state to prevent the brake signal from dithering, consistent with good engineering 

judgment.

(g) The driver model should be designed to follow the cycle as closely as possible and 

must meet the requirements of § 1037.510 for steady-state testing and 40 CFR 

1066.430(e) for transient testing. The driver model should be designed so that the brake 

and throttle are not applied at the same time.

* * * * *

Subpart G—[Amended]

28. Section 1037.615 is amended by revising paragraph (b)(1), redesignating paragraph 

(b)(3) as (b)(4), and adding a new paragraph (b)(3) to read as follows:

§ 1037.615 Hybrid vehicles and other advanced technologies.

* * * * *

(b) * * *

(1) Measure the effectiveness of the advanced system by chassis testing a vehicle 

equipped with the advanced system and an equivalent conventional vehicle, or by testing 

the hybrid systems and the equivalent non-hybrid systems as described in § 1037.550. 

Test the vehicles as specified in subpart F of this part. For purposes of this paragraph (b), 

a conventional vehicle is considered to be equivalent if it has the same footprint (as 

defined in 40 CFR 86.1803), vehicle service class, aerodynamic drag, and other relevant 
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factors not directly related to the hybrid powertrain. If you use § 1037.525 to quantify the 

benefits of a hybrid system for PTO operation, the conventional vehicle must have the 

same number of PTO circuits and have equivalent PTO power. If you do not produce an 

equivalent vehicle, you may create and test a prototype equivalent vehicle. The 

conventional vehicle is considered Vehicle A and the advanced vehicle is considered 

Vehicle B. We may specify an alternate cycle if your vehicle includes a power take-off.

* * * * *

(3) If you apply an improvement factor to multiple vehicle configurations using the same 

advanced technology, use the vehicle configuration with the smallest potential reduction 

in greenhouse gas emissions resulting from the hybrid capability. 

* * * * *

29. Section 1037.620 is amended by revising paragraph (a)(3) to read as follows:

§ 1037.620 Shipment of incomplete vehicles to secondary vehicle manufacturers.

* * * * *

(a) * * *

(3) Uncertified vehicles that will be certified by secondary vehicle manufacturers.

Manufacturers may introduce into U.S. commerce partially complete vehicles for which 

they do not hold a certificate of conformity only as allowed by paragraph (b) of this 

section; however, the requirements of this section do not apply if vehicles produced by a 

secondary vehicle manufacturer are excluded from the standards of this part under §

1037.150(c).
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* * * * *

30. Section 1037.660 is amended by revising the introductory text and paragraph (c) to 

read as follows:

§ 1037.660 Automatic engine shutdown systems.

This section specifies requirements that apply for certified automatic engine shutdown 

(AES) systems modeled under § 1037.520. It does not apply for AES systems you do not 

model under § 1037.520.

* * * * *

(c) Adjustments to AES systems. (1) The AES system may include an expiration point 

(in miles) after which the AES system may be disabled. If your vehicle is equipped 

with an AES system that expires before 1,259,000 miles, adjust the model input as 

follows, rounded to the nearest 0.1 g/ton-mile: AES Input = 5 g CO2/ton-mile × 

(miles at expiration/1,259,000 miles)

(2) For AES systems designed to limit idling to a specific number of hours less than 

1,800 hours over any 12-month period, calculate an adjusted AES input using the 

following equation, rounded to the nearest 0.1 g/ton-mile: AES Input = 5 g CO2/tonmile × (1 - (maximum allowable number of idling hours per year/1,800 hours)). This 

is an annual allowance that starts when the vehicle is new and resets every 12 months 

after that. Manufacturers may propose an alternative method based on operating 

hours or miles instead of years. 
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* * * * *

Subpart H—[Amended]

31. Section 1037.745 is amended by revising the section heading and adding paragraph 

(d) to read as follows:

§ 1037.745 End-of-year CO2 credit deficits.

* * * * *

(d) For purposes of calculating the statute of limitations, the following actions are all 

considered to occur at the expiration of the deadline for offsetting debits as specified in 

paragraph (a) of this section:

(1) Failing to meet the requirements of paragraph (a) of this section.

(2) Failing to satisfy the conditions upon which a certificate was issued relative to 

offsetting debits.

(3) Selling, offering for sale, introducing or delivering into U.S. commerce, or 

importing vehicles that are found not to be covered by a certificate as a result of 

failing to offset debits.

Subpart I—[Amended]

32. Section 1037.801 is amended by adding a definition for “Preliminary approval” in 

alphabetical order and revising the definition for “Regulatory sub-category” to read as 
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follows:

§ 1037.801 Definitions.

* * * * *

Preliminary approval means approval granted by an authorized EPA representative prior 

to submission of an application for certification, consistent with the provisions of § 

1037.210.

* * * * *

Regulatory sub-category means one of the following groups:

(1) All vehicles subject to the standards of § 1037.104. Note that this category includes 

most gasoline-fueled and diesel-fueled heavy-duty pickup trucks and vans.

(2) [Reserved]

(3) Vocational vehicles at or below 19,500 pounds GVWR.

(4) Vocational vehicles above 19,500 pounds GVWR but at or below 33,000 pounds 

GVWR. 

(5) Vocational vehicles over 33,000 pounds GVWR. 

(6) Low-roof tractors above 26,000 pounds GVWR but at or below 33,000 pounds 

GVWR. 

(7) Mid-roof tractors above 26,000 pounds GVWR but at or below 33,000 pounds 

GVWR. 

(8) High-roof tractors above 26,000 pounds GVWR but at or below 33,000 pounds 

GVWR. 

(9) Low-roof day cab tractors above 33,000 pounds GVWR. 
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(10) Low-roof sleeper cab tractors above 33,000 pounds GVWR. 

(11) Mid-roof day cab tractors above 33,000 pounds GVWR. 

(12) Mid-roof sleeper cab tractors above 33,000 pounds GVWR.

(13) High-roof day cab tractors above 33,000 pounds GVWR. 

(14) High-roof sleeper cab tractors above 33,000 pounds GVWR. 

* * * * *

33. Section 1037.805 is amended by adding an entry for “AES” in alphabetical order to 

read as follows:

§ 1037.805 Symbols, acronyms, and abbreviations.

* * * * *

AES Automatic engine shutdown.

* * * * *

34. Section 1037.810 is amended by revising paragraph (c)(1) to read as follows:

§ 1037.810 Incorporation by reference.

* * * * *

(c) * * *

(1) Greenhouse gas Emissions Model (GEM) simulation tool, Version 2.0.1, September

2012; IBR approved for § 1037.520. The computer code for this model is available as 
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noted in paragraph (a) of this section. A working version of this software is also available 

for download at http://www.epa.gov/otaq/climate/gem.htm.

* * * * *

PART 1039--CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD 

COMPRESSION-IGNITION ENGINES

35. The authority citation for part 1039 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart B—[Amended]

36. Section 1039.104 is amended by revising paragraph (g) to read as follows:

§ 1039.104 Are there interim provisions that apply only for a limited time?

* * * * *

(g) Alternate FEL caps. You may certify engines to the FEL caps in Table 1 of this 

section instead of the otherwise applicable FEL caps in § 1039.101(d)(1), § 1039.102(e), 

or § 1039.102(g)(2) for the indicated model years, subject to the following provisions:

(1) [Reserved] 

(2) If your engine is not certified to transient emission standards under the provisions 

of § 1039.102(a)(1)(iii), you must adjust your FEL upward by a temporary 

compliance adjustment factor (TCAF) before calculating your negative emission 

credits under § 1039.705, as follows:

(i) The temporary compliance adjustment factor for NOx and for NOx+NMHC is 

1.1.
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(ii) The temporary compliance adjustment factor for PM is 1.5.

(iii) The adjusted FEL (FELadj) for calculating emission credits is determined 

from the steady-state FEL (FELss) using the following equation:

FELadj= (FELss) × (TCAF)

(iv) The unadjusted FEL (FELss) applies for all purposes other than credit 

calculation.

(3) These alternate FEL caps may not be used for phase-in engines.

(4) Do not apply TCAFs to gaseous emissions for phase-out engines that you certify 

to the same numerical standards (and FELs if the engines are certified using ABT) for 

gaseous pollutants as you certified under the Tier 3 requirements of 40 CFR part 89.

Table 1 of § 1039.104—Alternate FEL Caps

Maximum engine 

power

PM FEL 

cap, g/kWhr

Model years for the 

alternate PM FEL cap

NOx FEL cap, 

g/kW-hr 1

Model years for the 

alternate NOx FEL cap

19 ≤ kW < 56 0.30 2012–2015 2

56 ≤ kW < 130 30.30 2012–2015 3.8 2012–2015 4

130 ≤ kW ≤ 560 0.20 2011–2014 3.8 2011–2014 5

kW > 560 60.10 2015–2018 3.5 2015–2018

1The FEL cap for engines demonstrating compliance with a NOx+NMHC standard is equal to the 

previously applicable NOx+NMHC standard specified in 40 CFR 89.112 (generally the Tier 3 standards).

2

For manufacturers certifying engines under Option #1 of Table 3 of § 1039.102, these alternate FEL caps 

apply to all 19–56 kW engines for model years from 2013 through 2016 instead of the years indicated in 

this table. For manufacturers certifying engines under Option #2 of Table 3 of § 1039.102, these alternate 

FEL caps do not apply to 19–37 kW engines except in model years 2013 to 2015.

3

For engines below 75 kW, the FEL caps are 0.40 g/kW-hr for PM emissions and 4.4 g/kW-hr for NOx

emissions.

4

For manufacturers certifying engines in this power category using a percentage phase-in/phase-out 

approach instead of the alternate NOx standards of § 1039.102(e)(1), the alternate NOx FEL cap in the 

table applies only in the 2014–2015 model years if certifying under § 1039.102(d)(1), and only in the 2015 

model year if certifying under § 1039.102(d)(2).

5

For manufacturers certifying engines in this power category using the percentage phase-in/phase-out 

approach instead of the alternate NOx standard of § 1039.102(e)(2), the alternate NOx FEL cap in the table 

applies only for the 2014 model year.

6

For engines above 560 kW, the provision for alternate NOx FEL caps is limited to generator-set engines. 
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(5) You may certify engines under this paragraph (g) in any model year provided for 

in Table 1 of this section without regard to whether or not the engine family's FEL is 

at or below the otherwise applicable FEL cap. For example, a 200 kW engine 

certified to the NOx+ NMHC standard of § 1039.102(e)(3) with an FEL equal to the 

FEL cap of 2.8 g/kW-hr may nevertheless be certified under this paragraph (g).

(6) For engines you produce under this paragraph (g) after the Tier 4 final standards 

take effect, you may certify based on a NOx+NMHC FEL as described in Table 1 of 

this section. Calculate emission credits for these engines relative to the applicable 

NOx standard in § 1039.101 or § 1039.102, plus 0.1 g/kW-hr.

* * * * *

Subpart G—[Amended]

37. Section 1039.625 is amended by revising paragraphs (e), (j), and (m) to read as 

follows:

§ 1039.625 What requirements apply under the program for equipmentmanufacturer flexibility?

* * * * *

(e) Standards. If you produce equipment with exempted engines under this section, the 

engines must meet emission standards specified in this paragraph (e), or more stringent 

standards. Note that we consider engines to be meeting emission standards even if they 

are certified with a family emission limit that is higher than the emission standard that 

would otherwise apply. 
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(1) If you are using the provisions of paragraph (d)(4) of this section, engines must 

meet the applicable Tier 1 or Tier 2 emission standards described in 40 CFR 89.112.

(2) If you are using the provisions of paragraph (a)(2) of this section, engines must be 

identical in all material respects to engines certified under this part 1039 as follows:

Engines in the following 

power category...

Must meet all standards and 

requirements that applied in the 

following model year...

(i) 19 < kW < 56 2008 (Option 1, where applicable)

(ii) 56 < kW < 130 2012 (Phase-out)

(iii) 130 < kW < 560 2011 (Phase-out)

(iv) kW > 560 2011

(3) In all other cases, engines at or above 56 kW and at or below 560 kW must meet 

the appropriate Tier 3 standards described in 40 CFR 89.112. Engines below 56 kW 

and engines above 560 kW must meet the appropriate Tier 2 standards described in 

40 CFR 89.112.

* * * * *

(j) Provisions for engine manufacturers. As an engine manufacturer, you may produce 

exempted engines as needed under this section. You do not have to request this 

exemption for your engines, but you must have written assurance from equipment 

manufacturers that they need a certain number of exempted engines under this section. 

Send us an annual report of the engines you produce under this section, as described in 

§ 1039.250(a). Exempt engines must meet the emission standards in paragraph (e) of this 

section and you must meet all the requirements of 40 CFR 1068.265, except that engines 

produced under the provisions of paragraph (a)(2) of this section must be identical in all 
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material respects to engines previously certified under this part 1039. If you show under 

40 CFR 1068.265(c) that the engines are identical in all material respects to engines that 

you have previously certified to one or more FELs above the standards specified in 

paragraph (e) of this section, you must supply sufficient credits for these engines. 

Calculate these credits under subpart H of this part using the previously certified FELs 

and the alternate standards. You must meet the labeling requirements in 40 CFR 89.110 

or § 1039.135, as applicable, with the following exceptions:

* * * * *

(m) Additional exemptions for technical or engineering hardship. You may request 

additional engine allowances under paragraph (b) of this section; however, you may use 

these extra allowances only for those equipment models for which you, or an affiliated 

company, do not also produce the engine. Additional allowances under this paragraph 

(m) must be used within the specified seven-year period. After considering the 

circumstances, we may permit you to introduce into U.S. commerce equipment with such 

engines that do not comply with Tier 4 emission standards, as follows:

(1) We may approve additional exemptions if extreme and unusual circumstances that 

are clearly outside your control and that could not have been avoided with reasonable 

discretion have resulted in technical or engineering problems that prevent you from 

meeting the requirements of this part. You must show that you exercised prudent 

planning and have taken all reasonable steps to minimize the scope of your request 

for additional allowances.
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(2) To apply for exemptions under this paragraph (m), send the Designated 

Compliance Officer a written request as soon as possible before you are in violation. 

In your request, include the following information:

(i) Describe your process for designing equipment.

(ii) Describe how you normally work cooperatively or concurrently with your 

engine supplier to design products.

(iii) Describe the engineering or technical problems causing you to request the 

exemption and explain why you have not been able to solve them. Describe the 

extreme and unusual circumstances that led to these problems and explain how 

they were unavoidable.

(iv) Describe any information or products you received from your engine supplier 

related to equipment design—such as written specifications, performance data, or 

prototype engines—and when you received it.

(v) Compare the design processes of the equipment model for which you need 

additional exemptions and that for other models for which you do not need 

additional exemptions. Explain the technical differences that justify your request.

(vi) Describe your efforts to find and use other compliant engines, or otherwise 

explain why none is available.

(vii) Describe the steps you have taken to minimize the scope of your request.

(viii) Include other relevant information. You must give us other relevant 

information if we ask for it.
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(ix) Estimate the increased percent of production you need for each equipment 

model covered by your request, as described in paragraph (m)(3) of this section. 

Estimate the increased number of allowances you need for each equipment model 

covered by your request, as described in paragraph (m)(4) of this section.

(3) We may approve your request to increase the allowances under paragraph (b)(1) 

of this section, subject to the following limitations:

(i) You must use up the allowances under paragraph (b)(1) of this section before 

using any additional allowance under this paragraph (m).

(ii) You may use these allowances only for the specific equipment models 

covered by your request.

(4) We may approve your request to increase the small-volume allowances under 

paragraph (b)(2) of this section, subject to the following limitations:

(i) You are eligible for additional allowances under this paragraph (m)(4) only if 

you do not use the provisions of paragraph (m)(3) of this section to obtain 

additional allowances within a given power category.

(ii) We may approve additional allowances in the form of waiving the annual 

limits specified in paragraph (b)(2) of this section instead of or in addition to 

increasing the total number of allowances under this paragraph (m)(4).

(iii) If we increase the total number of allowances, you may use these allowances 

only for the specific equipment models covered by your request.
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PART 1042--CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE 

COMPRESSION-IGNITION ENGINES AND VESSELS

38. The authority citation for part 1042 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart B—[Amended]

39. Section 1042.145 is amended by adding paragraph (j) to read as follows:

§ 1042.145 Interim provisions.

* * * * *

(j) Vessel manufacturers and marine equipment manufacturers may apply the provisions 

of § 1042.605 to land-based engines with maximum engine power at or above 19 kW and 

below 600 kW produced under the allowances provided in 40 CFR 1039.625 for model 

year 2013 marine engines. All the provisions of § 1042.605 apply as if those engines 

were certified to emission standards under 40 CFR part 1039. Similarly, engine 

manufacturers, vessel manufacturers, and marine equipment manufacturers must comply 

with all the provisions of 40 CFR 1039.625 as if those engines were installed in landbased equipment.

Subpart G—[Amended]

40. Section 1042.615 is amended as follows:

a.Bby revising the introductory text and paragraphs (a) introductory text and (a)(1).

b.By redesignating paragraphs (b) through (d) as paragraphs (c) through (e).
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a.c.By adding a new paragraph (b). and removing paragraph (a)(2)(v) to read as follows:

§ 1042.615 Replacement engine exemption.

For Category 1 and Category 2 replacement engines, the provisions of 40 CFR 1068.240 

apply except as described in this section. In unusual circumstances, you may ask us to 

allow you to apply these provisions for a new Category 3 engine.

(a) This paragraph (a) applies instead of the provisions of 40 CFR 1068.240(b)(2). The 

prohibitions in 40 CFR 1068.101(a)(1) do not apply to a new replacement engine if all 

the following conditions are met:

(1) You use good engineering judgment to determine that no engine certified to the 

current requirements of this part is produced by any manufacturer with the appropriate 

physical or performance characteristics to repower the vessel. We have determined that 

engines certified to Tier 4 standards do not have the appropriate physical or performance 

characteristics to replace uncertified engines or engines certified to emission standards 

that are less stringent than the Tier 4 standards.

* * * * *

(b) The 25-year limit specified in 40 CFR 1068.240(a) does not apply for engines subject 

to this part 1042. You may accordingly omit the statement on the permanent labels 

specified in 40 CFR 1068.240 describing this limitation.

(a)

* * * * *

(2) * * *
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(v) [Reserved]

* * * * *

PART 1048— CONTROL OF EMISSIONS FROM NEW, LARGE NONROAD 

SPARK-IGNITION ENGINES

40.41. The authority citation for part 1048 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart B—[Amended]

41.42. Section 1048.105 is amended by revising paragraph (a) to read as follows:

§ 1048.105 What evaporative emission standards and requirements apply? 

* * * * *

(a) Fuel line permeation. For nonmetallic fuel lines, you must specify and use products 

that meet the Category 1 specifications for permeation in the November 1996 or 

November 2004 versions of SAE J2260 (both incorporated by reference in § 1048.810). 

* * * * *

Subpart I—[Amended]

42.43. Section 1048.810 is revised to read as follows:

§ 1048.810 What materials does this part 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 
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edition other than that specified in this section, the Environmental Protection Agency 

must publish a notice of the change in the Federal Register and the material must be 

available to the public. All approved material is available for inspection at U.S. EPA, Air 

and Radiation Docket and Information Center, 1301 Constitution Ave., NW., Room 

B102, EPA West Building, Washington, DC 20460, (202) 202–1744, and is available 

from the sources listed below. It is also available for inspection at the National Archives 

and Records Administration (NARA). For information on the availability of this material 

at NARA, call 202–741–6030, or go to 

http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html

.

(b) Society of Automotive Engineers, 400 Commonwealth Dr., Warrendale, PA 15096–

0001, (877) 606–7323 (U.S. and Canada) or (724) 776–4970 (outside the U.S. and 

Canada), http://www.sae.org. 

(1) SAE J2260, Nonmetallic Fuel System Tubing with One or More Layers, 

November 2004; IBR approved for § 1048.105(a).

(2) SAE J2260, Nonmetallic Fuel System Tubing with One or More Layers, 

November 1996; IBR approved for § 1048.105(a).

(c) International Organization for Standardization, Case Postale 56, CH–1211 Geneva 20, 

Switzerland, (41) 22749 0111, http://www.iso.org, or central@iso.org. 

(1) ISO 9141-2 Road vehicles—Diagnostic systems— Part 2: CARB requirements for 

interchange of digital information, February 1994; IBR approved for § 1048.110(g).

(2) ISO 14230-4 Road vehicles—Diagnostic systems—Keyword Protocol 2000—
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Part 4: Requirements for emission-related systems, June 2000; IBR approved for § 

1048.110(g).

PART 1054—CONTROL OF EMISSIONS FROM NEW, SMALL NONROAD 

SPARK-IGNITION ENGINES AND EQUIPMENT

43.44. The authority citation for part 1054 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart B—[Amended]

44.45. Section 1054.145 is amended by revising paragraphs (c)(3) and (n) to read as 

follows:

§ 1054.145 Are there interim provisions that apply only for a limited time?

* * * * *

(c) * * *

(3) Engines subject to Phase 3 emission standards must meet the standards at or above 

barometric pressures of 96.0 kPa in the standard configuration and are not required to 

meet emission standards at lower barometric pressures. This is intended to allow testing 

under most weather conditions at all altitudes up to 1,100 feet above sea level. In your 

application for certification, identify the altitude above which you rely on an altitude kit 

and describe your plan for making information and parts available such that you would 

reasonably expect that altitude kits would be widely used at all such altitudes.
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* * * * *

(n) California test fuel. Through model year 2019, you may perform testing with a fuel 

meeting the requirements for certifying the engine in California instead of the fuel 

specified in § 1054.501(b)(2), as follows:

(1) You may certify individual engine families using data from testing conducted with 

California Phase 2 test fuel. Any EPA testing with such an engine family may use 

either this same certification fuel or the test fuel specified in § 1054.501.

(2) Starting in model year 2013, you may certify individual engine families using data 

from testing conducted with California Phase 3 test fuel. Any EPA testing with such 

an engine family may use either this same certification fuel or the test fuel specified 

in § 1054.501, unless you certify to the more stringent CO standards specified in this 

paragraph (n)(2). If you meet these alternate CO standards, we will also use 

California Phase 3 test fuel for any testing we perform with engines from that engine 

family. The following alternate CO standards apply instead of the CO standards 

specified in § 1054.103 or § 1054.105:

Table 1 to § 1054.145—Alternate CO Standards for 

Testing with California Phase 3 Test Fuel (g/kW-hr)

Engine type Alternate CO standard

Class I 549

Class II 549

Class III 536

Class IV 536

Class V 536

Marine generators 4.5

* * * * *
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Subpart F—[Amended]

45.46. Section 1054.501 is amended by revising paragraph (b)(2) to read as follows:

§ 1054.501 How do I run a valid emission test?

* * * * *

(b) * * *

(2) Use the appropriate fuels and lubricants specified in 40 CFR part 1065, subpart H, for 

all the testing we require in this part. Except as specified in paragraph (d) of this section, 

use gasoline specified for general testing. For service accumulation, use the test fuel or 

any commercially available fuel that is representative of the fuel that in-use engines will 

use. Note that § 1054.145(n) allows for testing with gasoline test fuels specified by the 

California Air Resources Board for any individual engine family through model year 

2019. 

* * * * *

PART 1065—Engine-Testing Procedures

46.47. The authority citation for part 1065 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart C—[Amended]

47.48. Section 1065.275 is amended by revising the section heading to read as follows:

§ 1065.275 N2O measurement devices.
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* * * * *

Subpart G—[Amended]

48.49. Section 1065.610 is amended by revising paragraph (c)(3) to read as follows:

§ 1065.610 Duty cycle generation.

* * * * *

(c) * * *

(3) Intermediate speed. If your normalized duty cycle specifies a speed as “intermediate 

speed,” use your torque-versus-speed curve to determine the speed at which maximum 

torque occurs. This is peak torque speed. If maximum torque occurs in a flat region of the 

torque-versus-speed curve, your peak torque speed is the midpoint between the lowest 

and highest speeds at which the trace reaches the flat region. For purposes of this 

paragraph (c)(3), a flat region is one in which measured torque values are within 2% of 

the maximum recorded value. Identify your reference intermediate speed as one of the 

following values:

(i) Peak torque speed if it is between (60 and 75) % of maximum test speed.

(ii) 60 % of maximum test speed if peak torque speed is less than 60 % of maximum 

test speed.

(iii) 75 % of maximum test speed if peak torque speed is greater than 75 % of 

maximum test speed.

* * * * *
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PART 1066—Vehicle-Testing Procedures

49.50. The authority citation for part 1066 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart D—[Amended]

50.51. Section 1066.310 is amended by revising the section heading, the introductory 

text, and paragraphs (b)(2), (b)(3) introductory text, (b)(3)(i), and (b)(6) through 

(b)(8) and removing and reserving paragraph (b)(3)(ii) to read as follows:

§ 1066.310 Coastdown procedures for vehicles with GVWR above 14,000 lbs.

This section describes coastdown procedures that are unique to heavy-duty vehicles with 

GVWR above 14,000 lbs. 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 Greenhouse gas Emissions Model (GEM) simulation tool under 

40 CFR part 1037.

* * * * *

(b) * * *

(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. Data collection must occur through a minimum speed at or below 15 mph. 
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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) [Reserved]

* * * * *

(6) All valid coastdown run times in each direction must be within 2.0 standard

deviations of the mean of the valid coastdown run times (from 70 mph down to 15 mph) 

in that direction. Eliminate runs outside this range. After eliminating these runs you 

must have at least eight valid runs in each direction. You may use coastdown run times 

that do not meet these standard deviation requirements if we approve it in advance. In 

your request, describe why the vehicle is not able to meet the specified standard deviation 

requirements and propose an alternative set of requirements.

(7) Analyze data for chassis and post-transmission powerpack testing or for use in the 

GEM simulation tool as follows:
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(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) For the GEM simulation tool, 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 vehicle 

mass for each tire making road contact. This accounts for the rotational inertia of the 

wheels and tires.

(C) Calculate the road-load force for each measurement interval, Fi, using the following 

equation:

i i 1

i e

v v F M

t

Eq. 1066.310-1

Where:

Me = the vehicle’s effective mass, expressed to the nearest 0.1 kg. 

v = vehicle speed at the beginning and end of the measurement interval. Let v0 = 0 m/s.

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:
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Eq. 1066.310-2

Where:

g = gravitational acceleration = 9.81 m/s2.

Δh = change in height or altitude over the measurement interval, in m. Assume Δh = 0 if 

you are not correcting for grade. 

Δs = distance the vehicle travels down the road during the measurement interval, in m.

Am = the calculated value of the y-intercept based on the curve-fit.

(E) Calculate drag area, CDA, in m2using the following equation:

adj

D

2 D

C A

Eq. 1066.310-3

Where:

ρ = air density at reference conditions = 1.17 kg/m3.

adj

B

98.21

293

T D D

P

Eq. 1066.310-4

T

= average ambient temperature during testing, in K.

PB

= 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 

2

i e m i

h

F M g A D v

s
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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

PART 1068--GENERAL COMPLIANCE PROVISIONS FOR HIGHWAY, 

STATIONARY, AND NONROAD PROGRAMS

51.52. The authority citation for part 1068 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart A—[Amended]

52.53. Section § 1068.1 is amended by revising paragraph (b) to read as follows:

§ 1068.1 Does this part apply to me?

* * * * *

(b) This part does not apply to any of the following engine or vehicle categories:

(1) Light-duty motor vehicles (see 40 CFR part 86).

(2) Highway motorcycles (see 40 CFR part 86).

(3) Heavy-duty motor vehicles and motor vehicle engines, except as specified in 40 CFR 

parts 85 and 86.

(4) Aircraft engines, except as specified in 40 CFR part 87.
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(5) Land-based nonroad compression-ignition engines we regulate under 40 CFR part 89.

(6) Small nonroad spark-ignition engines we regulate under 40 CFR part 90.

(7) Marine spark-ignition engines we regulate under 40 CFR part 91.

(8) Locomotive engines we regulate under 40 CFR part 92.

(9) Marine compression-ignition engines we regulate under 40 CFR parts 89 or 94.

* * * * *

Subpart C—[Amended]

53.54. Section § 1068.240 is revised to read as follows:

§ 1068.240 What are the provisions for exempting new replacement engines?

The prohibitions in § 1068.101(a)(1) do not apply to a new engine if it is exempt under 

this section as a replacement engine. For purposes of this section, a replacement engine 

is a new engine that is used to replace an engine that has already been placed into service 

(whether the previous engine is replaced in whole or in part with a new engine). 

(a) General provisions. You are eligible for the exemption for new replacement engines 

only if you are a certificate holder. Note that this exemption does not apply for 

locomotives (40 CFR 1033.601) and that unique provisions apply to marine compressionignition engines (40 CFR 1042.615). 

(1) Paragraphs (b), (c), and (d) of this section describe different approaches for 

exempting new replacement engines where the engines are specially built to 

correspond to an engine model from an earlier model year that was subject to less 
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stringent standards than those that apply for current production (or is no longer 

covered by a certificate of conformity). 

(2) Paragraph (e) of this section describes a simpler approach for exempting partially 

complete new replacement engines that are built under a certificate of conformity that 

is valid for producing engines for the current model year. 

(3) For all the different approaches described in paragraphs (b) through (e) of this 

section, the exemption applies only for equipment that is 25 years old or less at the 

time of installation. 

(b) Previous-tier replacement engines with tracking. You may produce any number of

new engines to replace an engine already placed into service in a piece of equipment, as 

follows: 

(1) The engine being replaced must have been either not originally subject to 

emission standards or originally subject to less stringent emission standards than 

those that apply to a new engine meeting current standards. The provisions of this 

paragraph (b) also apply for engines that were originally certified to the same 

standards that apply for the current model year if you no longer have a certificate of 

conformity to continue producing that engine configuration.

(2) The following requirements and conditions apply for engines exempted under this 

paragraph (b):

(i) You must determine that you do not produce an engine certified to meet current 

requirements that has the appropriate physical or performance characteristics to 

repower the equipment. If the engine being replaced was made by a different 
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company, you must make this determination also for engines produced by this other 

company.

(ii) In the case of premature engine failure, if the old engine was subject to emission 

standards, you must make the new replacement engine in a configuration identical in 

all material respects to the old engine and meet the requirements of § 1068.265. You 

may alternatively make the new replacement engine in a configuration identical in all 

material respects to another certified engine of the same or later model year as long as 

the engine is not certified with a family emission limit higher than that of the old 

engine.

(iii) For cases not involving premature engine failure, you (3) You must make a 

separate determination for your own product line addressing every tier of emission 

standards that is more stringent than the emission standards for the engine being 

replaced. For example, if the engine being replaced was built before the Tier 1 

standards started to apply and engines of that size are currently subject to Tier 3 

standards, you must also consider whether any Tier 1 or Tier 2 engines that you 

produce have the appropriate physical and performance characteristics for replacing 

the old engine; if you produce a Tier 2 engine with the appropriate physical and 

performance characteristics, you must use it as the replacement engine. 

(iv) You must keep records to document your basis for making the determinations 

paragraphs (b)(2)(i) and (iii) of this sectionin paragraph (b)(2) of this section and in 

this paragraph (b)(3).
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(43) The old engine block may be reintroduced into U.S. commerce as part of an 

engine that meets either the current standards for new engines, the provisions for new 

replacement engines in this section, or another valid exemption. Otherwise, you must 

destroy the old engine block or confirm that it has been destroyed.

(45) If the old engine was subject to emission standards, the replacement engine must 

meet the appropriate emission standards as specified in § 1068.265. This generally 

means you must make the new replacement engine in a previously certified 

configuration.

(56) Except as specified in paragraph (d) of this section, you must add a permanent 

label, consistent with § 1068.45, with your corporate name and trademark and the 

following additional information:

(i) Add the following statement if the new engine may only be used to replace an 

engine that was not subject to any emission standards under this chapter:

THIS REPLACEMENT ENGINE IS EXEMPT UNDER 40 CFR 1068.240. 

SELLING OR INSTALLING THIS ENGINE FOR ANY PURPOSE OTHER 

THAN TO REPLACE AN UNREGULATED ENGINE MAY BE A 

VIOLATION OF FEDERAL LAW SUBJECT TO CIVIL PENALTY. THIS 

ENGINE MAY NOT BE INSTALLED IN EQUIPMENT THAT IS MORE 

THAN 25 YEARS OLD AT THE TIME OF INSTALLATION.

(ii) Add the following statement if the new engine may replace an engine that was 

subject to emission standards:
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THIS ENGINE COMPLIES WITH U.S. EPA EMISSION REQUIREMENTS 

FOR [Identify the appropriate emission standards (by model year, tier, or 

emission levels) for the replaced engine] ENGINES UNDER 40 CFR 1068.240.

SELLING OR INSTALLING THIS ENGINE FOR ANY PURPOSE OTHER 

THAN TO REPLACE A [Identify the appropriate emission standards for the 

replaced engine, by model year(s), tier(s), or emission levels)] ENGINE MAY BE 

A VIOLATION OF FEDERAL LAW SUBJECT TO CIVIL PENALTY. THIS 

ENGINE MAY NOT BE INSTALLED IN EQUIPMENT THAT IS MORE 

THAN 25 YEARS OLD AT THE TIME OF INSTALLATION.

(76) Engines exempt under this paragraph (b) may not be introduced into U.S. 

commerce before you make the determinations under paragraph (b)(2) and (3) of this 

section, except as specified in this paragraph (b)(76). We may waive this restriction 

for engines excluded under paragraph (c)(5) of this section that you ship to a 

distributor. Where we waive this restriction, you must take steps to ensure that the 

engine is installed consistent with the requirements of this paragraph (b). For 

example, at a minimum you must report to us annually whether engines we allowed 

you to ship to a distributor under this paragraph (b)(76) have been placed into service 

or remain in inventory. After an engine is placed into service, your report must 

describe how the engine was installed consistent with the requirements of this 

paragraph (b). Send these reports to the Designated Compliance Officer by the 

deadlines we specify.
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(c) Previous-tier replacement engines without tracking. You may produce a limited 

number of new replacement engines that are not from a currently certified engine family 

under the provisions of this paragraph (c). If you produce new engines under this 

paragraph (c) to replace engines subject to emission standards, the new replacement 

engine must be in a configuration identical in all material respects to the old engine and 

meet the requirements of § 1068.265. You may make the new replacement engine in a 

configuration identical in all material respects to another certified engine of the same or 

later model year as long as the engine is not certified with a family emission limit higher 

than that of the old engine. The provisions of this paragraph (c) also apply for engines 

that were originally certified to the same standards that apply for the current model year 

if you no longer have a certificate of conformity to continue producing that engine 

configuration. This would apply, for example, for engine configurations that were 

certified in an earlier model year but are no longer covered by a certificate of conformity. 

You must comply with the requirements of paragraph (b) of this section for any number 

of replacement engines you produce in excess of what we allow under this paragraph (c). 

Engines produced under this paragraph (c) may be redesignated as engines subject to 

paragraph (b) of this section, as long as you meet all the requirements and conditions of 

paragraph (b) of this section before the deadline for the report specified in paragraph 

(c)(3) of this section. The following provisions apply to engines exempted under this 

paragraph (c):

(1) You may produce a limited number of replacement engines under this paragraph 

(c) representing 0.5 percent of your annual production volumes for each category and 
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subcategory of engines identified in Table 1 to this section (1.0 percent through 

2013). Calculate this number by multiplying your annual U.S.-directed production 

volume by 0.005 (or 0.01 through 2013) and rounding to the nearest whole number. 

Determine the appropriate production volume by identifying the highest total annual 

U.S.-directed production volume of engines from the previous three model years for 

all your certified engines from each category or subcategory identified in Table 1 to 

this section, as applicable. In unusual circumstances, you may ask us to base your 

production limits on U.S.-directed production volume for a model year more than 

three years prior. You may include stationary engines and exempted engines as part 

of your U.S.-directed production volume. Include U.S.-directed engines produced by 

any parent or subsidiary companies and those from any other companies you license 

to produce engines for you. 

(2) Count every exempted new replacement engine from your total U.S.-directed 

production volume that you produce in a given calendar year under this paragraph (c), 

including partially complete engines, except for the following:

(i) Engines built to specifications for an earlier model year under paragraph (b) of 

this section.

(ii) Partially complete engines exempted under paragraph (e) of this section.

(3) Send the Designated Compliance Officer a report by March 31 of the year 

following any year in which you produced exempted replacement engines under this 

paragraph (c). In your report include the total number of replacement engines you 

produce under this paragraph (c) for each category or subcategory, as appropriate, and 
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the corresponding total production volumes determined under paragraph (c)(1) of this 

section. If you send us a report under this paragraph (c)(3), you must also include the 

total number of replacement engines you produced under paragraphs (b), (d), and (e) 

of this section. You may include this information in production reports required 

under the standard-setting part.

(4) Add a permanent label as specified in paragraph (b)(65) of this section. For 

partially complete engines, you may alternatively add a permanent or removable label 

as specified in paragraph (d) of this section.

(5) You may not use the provisions of this paragraph (c) for any engines in the 

following engine categories or subcategories:

(i) Land-based nonroad compression-ignition engines we regulate under 40 CFR 

part 1039 with a per-cylinder displacement at or above 7.0 liters.

(ii) Marine compression-ignition engines we regulate under 40 CFR part 1042 

with a per-cylinder displacement at or above 7.0 liters.

(iii) Locomotive engines we regulate under 40 CFR part 1033.

(d) Partially complete engines. The following requirements apply if you ship a partially 

complete replacement engine under this section:

(1) Provide instructions specifying how to complete the engine assembly such that the 

resulting engine conforms to the applicable certificate of conformity or the 

specifications of § 1068.265. Where a partially complete engine can be built into 

multiple different configurations, you must be able to identify all the engine models 

and model years for which the partially complete engine may properly be used for 
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replacement purposes. Your instructions must make clear how the final assembler 

can determine which configurations are appropriate for the engine they receive. 

(2) You must label the engine as follows:

(i) If you have a reasonable basis to believe that the fully assembled engine will 

include the original emission control information label, you may add a removable 

label to the engine with your corporate name and trademark and the statement: 

"This replacement engine is exempt under 40 CFR 1068.240." This would 

generally apply if all the engine models that are compatible with the replacement 

engine were covered by a certificate of conformity and they were labeled in a 

position on the engine or equipment that is not included as part of the partially 

complete engine being shipped for replacement purposes. Removable labels must 

meet the requirements specified in § 1068.45.

(ii) If you do not qualify for using a removable label in paragraph (d)(1) of this 

section, you must add a permanent label in a readily visible location, though it 

may be obscured after installation in a piece of equipment. Include on the

permanent label your corporate name and trademark, the engine's part number (or 

other identifying information), and the statement: "THIS REPLACEMENT 

ENGINE IS EXEMPT UNDER 40 CFR 1068.240; IT MAY NOT BE 

INSTALLED IN EQUIPMENT THAT IS MORE THAN 25 YEARS OLD AT 

THE TIME OF INSTALLATION." If there is not enough space for this 

statement, you may alternatively add: "REPLACEMENT" or "SERVICE 

ENGINE". For purposes of this paragraph (d)(2), engine part numbers 
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permanently stamped or engraved on the engine are considered to be included on 

the label.

(e) Partially complete current-tier replacement engines. The provisions of paragraph (d) 

of this section apply for partially complete engines you produce from a current line of 

certified engines or vehicles. This applies for engine-based and equipment-based 

standards as follows:

(1) Where engine-based standards apply, you may introduce into U.S. commerce 

short blocks or other partially complete engines from a currently certified engine 

family as replacement components for in-use equipment powered by engines you 

originally produced. You must be able to identify all the engine models and model 

years for which the partially complete engine may properly be used for replacement 

purposes. 

(2) Where equipment-based standards apply, you may introduce into U.S. commerce 

engines that are identical to engines covered by a current certificate of conformity by 

demonstrating compliance with currently applicable standards where the engines will 

be installed as replacement engines. These engines might be fully assembled, but we 

would consider them to be partially complete engines because they are not yet 

installed in the equipment. 

(f) Emission credits. Replacement engines exempted under this section may not generate 

or use emission credits under the standard-setting part nor be part of any associated credit 

calculations.
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Table 1 to § 1068.240— Engine categories and subcategories for new 

replacement engines exempted without tracking 

Engine category Standard-setting part1 Engine subcategories

Highway CI 40 CFR part 86

disp. < 0.6 L/cyl

0.6 < disp. < 1.2 L/cyl

disp. > 1.2 L/cyl

Nonroad CI, Stationary CI, and 

Marine CI

40 CFR part 1039, or

40 CFR part 1042

disp. < 0.6 L/cyl

0.6 < disp. < 1.2 L/cyl

1.2 < disp. < 2.5 L/cyl

2.5 < disp. < 7.0 L/cyl

Marine SI 40 CFR part 1045 outboard

personal watercraft

Large SI, Stationary SI, and Marine 

SI (sterndrive/ inboard only)

40 CFR part 1048 or

40 CFR part 1045

all engines

Recreational vehicles 40 CFR part 1051

off-highway motorcycle

all-terrain vehicle

snowmobile

Small SI and Stationary SI 40 CFR part 1054

handheld

Class I

Class II

1

Include an engine as being subject to the identified standard-setting part if it will eventually be subject 

to emission standards under that part. For example, if you certify marine compression-ignition engines 

under part 94, count those as if they were already subject to part 1042.

PART 523—VEHICLE CLASSIFICATION

54.55. The authority citation for part 523 is amended to read as follows:

Authority: 49 U.S.C. 32901, delegation of authority at 49 CFR 1.95

55.56. Section 523.2 is amended by revising the following definitions:

* * * * *.

Complete vehicle means a vehicle, other than in Part 523.7, that requires no further 

manufacturing operations to perform its intended function and is a functioning vehicle 

that has the primary load carrying device or container (or equivalent equipment) attached 

or that is designed to pull a trailer. Examples of equivalent equipment would include fifth 
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wheel trailer hitches, firefighting equipment, and utility booms.

* * * * *.

Incomplete vehicle means a vehicle, other than in Part 523.7, which does not have the 

primary load carrying device or container attached when it is first sold as a vehicle or any 

vehicle that does not meet the definition of a complete vehicle. This may include vehicles 

sold to secondary vehicle manufacturers. Incomplete vehicles include cab-complete 

vehicles.

* * * * *.

56.57. Section 523.7 is amended by revising the following definition:

§ 523.7 Heavy-duty pickup trucks and vans.

Heavy-duty pickup trucks and vans are pickup trucks and vans with a gross vehicle 

weight rating between 8,501 pounds and 14,000 pounds (Class 2b through 3 vehicles) 

manufactured as complete vehicles by a single or final stage manufacturer or 

manufactured as incomplete vehicles as designated by a manufacturer. A manufacturer 

may also optionally designate as a heavy-duty pickup truck or van any cab-complete or 

complete vehicle having a GVWR over 14,000 pounds and below 26,001 pounds 

equipped with a spark ignition engine or any spark ignition engine certified and sold as a 

loose engine manufactured for use in a heavy-duty pickup truck or van. See references in 

49 CFR 535.5(a), 40 CFR 1037.104 and 40 CFR 1037.150. Complete and incomplete 

vehicles between 8,501 pounds and 14,000 pounds have the meaning for complete and 

incomplete heavy-duty vehicles given in 40 CFR 86.1803.

* * * * *.
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PART 535 MEDIUM- AND HEAVY-DUTY VEHICLE FUEL EFFICIENCY 

PROGRAM

57.58. The authority citation for part 535 is amended to read as follows:

Authority: 49 U.S.C 32901, delegation of authority at 49 CFR 1.95.

58.59. Revise § 535.3(b) and (c) to read as follows:

* * * * *.

§ 535.3 Applicability.

* * * * *.

(b) Complete vehicle manufacturers, for the purpose of this part, include primary and 

secondary stage manufacturers meeting the criteria in 1037.620 that produce heavy-duty 

pickup trucks and vans or truck tractors as complete vehicles and, that hold the EPA 

certificate of conformity. 

(c) Chassis manufacturers, for the purpose of this part, include primary and secondary 

stage manufacturers meeting the criteria in 1037.620 that produce incomplete vehicles 

constructed for use as heavy-duty pickup trucks or vans or heavy-duty vocational 

vehicles and that hold the EPA certificate of conformity. Some vocational vehicle 

manufacturers are both chassis and complete vehicle manufacturers. These manufacturers 

will be regulated as chassis manufacturers under this program.

* * * * *.

59.60. Revise § 535.4 by adding the following definition for credit holder and revising 

the definitions for configuration and subconfiguration:
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§ 535.4 Definitions.

* * * * *.

Configuration means a subclassification within a test group which is based on engine 

code, transmission type and gear ratios, final drive ratio and other parameters which EPA 

designates. Transmission type means the basic type of the transmission (e.g. automatic, 

manual, automated manual, semi-automatic, or continuously variable) and does not 

include the drive system of the vehicle (e.g. front-wheel drive, rear-wheel drive, and fourwheel drive). Engine code means the combination of both “engine code” and “basic 

engine” as defined in the provisions of 40 CFR 600.002. 

* * * * *.

Credit holder (or holder) means a legal person that has credits, either because they are the 

manufacturer who earned the credits by exceeding the applicable fuel consumption 

standard and are the certificate holder, or because they are a designated recipient who has 

received credits from another holder. Credit holders need not be manufacturers but credit 

holders that are not manufacturers may only purchase and hold credits for the purpose of 

retiring them as specified in 40 CFR 1036.701(h) and 1037.701(e). 

* * * * *.

Subconfiguration means a unique combination within a vehicle configuration of 

equivalent test weight, road-load horsepower, and any other operational characteristics or 

parameters that EPA determines may significantly affect CO2 emissions within a vehicle 

configuration. Note that for vehicles subject to heavy-duty pickup truck and van 
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standards, equivalent test weight (ETW) is based on the ALVW of the vehicle as outlined 

in paragraph 40 CFR 1037.104(d)(11).

* * * * *.

60.61. Revise § 535.5 by amending section 535.5(a)(4)(i) and adding sections 

535.5(a)(4)(v) and (vi) as follows:

§ 535.5 Standards.

(a) * * *

(4) Voluntary standards. (i) Manufacturers may choose voluntarily to comply early with 

fuel consumption standards for model years 2013 through 2015, as determined in 

paragraphs (a)(4)(iii) and (iv) of this section, for example, in order to begin accumulating 

credits through over-compliance with the applicable standard. A manufacturer choosing 

early compliance must comply with all the vehicles and engines it manufactures in each 

regulatory category for a given model year except as provided in paragraphs (v) and (vi).

* * * * *.

(v) For model year 2013, a manufacturer can choose to comply with the standards in 

535.5(a) and generate early credits under 535.7(b) by using the entire U.S.-directed 

production volume of vehicles other than electric vehicles as specified in 40 CFR 

1037.150. The model year 2014 standards in 535.5(a) apply for vehicles complying in 

model year 2013. If some test groups are certified by EPA after the start of the model 

year, the manufacturer may only generate credits under 535.7(b) for the production that 

occurs after all test groups are certified in accordance with 40 CFR 1037.150 (a)(2). 
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(vi) For model year 2014, a manufacturer producing model year 2014 vehicles before 

January 1, 2014, may optionally elect to comply with these standards for a partial model 

year that begins on January 1, 2014, and ends on the day the manufacturer's model year 

would normally end if it meets the provisions in 40 CFR 1037.150(g).

* * * * *

8. Revise § 535.5(a)(6) to read as follows:

 (6) Optional certification under this section. A manufacturer may optionally certify 

any spark ignition (or gasoline) cab-complete or complete vehicle weighing over 14,000 

pounds GVWR and below 26,001 pounds GVWR to the requirements under this 

paragraph (a) that applies to a comparable complete sister vehicle as determined in 

accordance with 40 CFR 1037.150(l). Calculate the target standard value under 

paragraph (a)(2) of this section based on the same work factor value that applies for the 

complete sister vehicle.

* * * * *

9. Revise § 535.5 by revising section 535.5(b)(2) (i) and adding sections 535.5(b)(2)(iii) 

and (iv) as follows:

(b) * * *

(2) Voluntary compliance. (i) For model years 2013 through 2015, a manufacturer may 

choose voluntarily to comply early with the fuel consumption standards provided in 

paragraph (b)(3) of this section. For example, a manufacturer may choose to comply 

early in order to begin accumulating credits through over-compliance with the applicable 

standards. A manufacturer choosing early compliance must comply with all the vehicles 
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and engines it manufacturers in each regulatory category for a given model year except as 

provided in paragraphs (iii) through (iv). 

* * * * *.

(iii) For model year 2013, a manufacturer can choose to comply with the standards in 

535.5(b) and generate early credits under 535.7(c) by using the entire U.S.-directed 

production volume within any of its regulatory sub-categories of vehicles other than 

electric vehicles as specified in 40 CFR 1037.150. The model year 2014 standards in 

535.5(b) apply for vehicles complying in model year 2013. If some vehicle families 

within a regulatory subcategory are certified by EPA after the start of the model year, 

manufacturers may generate credits under 535.7(c) only for production that occurs after 

all families are certified in accordance with 40 CFR 1037.150(a)(1).

(iv) For model year 2014, a manufacturer producing model year 2014 vehicles before 

January 1, 2014, may optionally elect to comply with these standards for a partial model 

year that begins on January 1, 2014, and ends on the day the manufacturer's model year 

would normally end if it meets the provisions in 40 CFR 1037.150(g). 

* * * * *

10. Revise § 535.5 by revising section 535.5(c)(2)(i) and adding sections 535.5(c)(2)(iii) 

and (iv) as follows:

(c) * * *

(2) Voluntary compliance. (i) For model years 2013 through 2015, a manufacturer may 

choose voluntarily to comply early with the fuel consumption standards provided in 

paragraph (c)(3) of this section. For example, a manufacturer may choose to comply 
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early in order to begin accumulating credits through over-compliance with the applicable 

standards. A manufacturer choosing early compliance must comply with all the vehicles 

and engines it manufacturers in each regulatory category for a given model year except as 

provided in paragraphs (iii) through (iv). 

* * * * *.

(iii) For model year 2013, a manufacturer can choose to comply with the standards in

535.5(c) and generate early credits under 535.7(c) by using the entire U.S.-directed 

production volume within any of its regulatory sub-categories of vehicles other than 

electric vehicles as specified in 40 CFR 1037.150. The model year 2014 standards in 

535.5(c) apply for vehicles complying in model year 2013. If some vehicle families 

within a regulatory subcategory are certified by EPA after the start of the model year, 

manufacturers may generate credits under 535.7(c) only for production that occurs after 

all families are certified in accordance with 40 CFR 1037.150(a)(1). 

(iv) For model year 2014, a manufacturer producing model year 2014 vehicles before 

January 1, 2014, may optionally elect to comply with these standards for a partial model 

year that begins on January 1, 2014, and ends on the day the manufacturer's model year 

would normally end if it meets the provisions in 40 CFR 1037.150(g). 

* * * * *

11. Revise § 535.5(c)(5) to read as follows:

(5) Vocational tractors. Tractors meeting the definition of vocational tractors in 49 CFR 

523.2 for purposes of certifying vehicles to fuel consumption standards, are divided into 

families of vehicles as specified in 1037.230(a)(1) and must comply with standards for 
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heavy-duty vocational vehicles and engines of the same weight class specified in 

paragraphs (b) and (d) of this section. Class 7 and Class 8 tractors certified or exempted 

as vocational tractors are limited in production to no more than 21,000 vehicles in any 

three consecutive model years. If a manufacturer is determined as not applying this 

allowance in good faith by the EPA in its applications for certification in accordance with 

40 CFR 1037.205 and 1037.630, a manufacturer must comply with the tractor fuel 

consumption standards in paragraph (c)(3) of this section. Vocational tractors generating 

credits can trade and transfer credits in the same averaging sets as tractors and vocational 

vehicles in the same weight class.

* * * * *.

12. Revise § 535.6(b)(3) to read as follows:

§ 535.6 Measurement and calculation procedures.

* * * * *.

(b) * * *

(3) From the GEM results, select the CO2 family emissions level (FEL) and equivalent 

fuel consumption values for vocational vehicle and tractor families in each regulatory 

subcategories for each model year. Equivalent fuel consumption FELs are derived in 

GEM from the CO2 FEL value rounded to the nearest whole number and are expressed to 

the nearest 0.1 gallons per 1000 ton-mile. For families containing multiple subfamilies, 

identify the FELs for each subfamily. 

* * * * *

13. Revise § 535.7(a) to read as follows:
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§ 535.7 Averaging, banking, and trading (ABT) program.

(a) Fuel consumption credits (FCC). At the end of each model year, primary and 

secondary manufacturers as specified in § 535.3 may earn credits for heavy-duty 

vehicles and engines exceeding the fuel consumption standards in § 535.5 or by using 

one or more of the flexibilities in this paragraph (a) to gain credits. Manufacturers may 

average, bank, and trade fuel consumption credits for purposes of complying with fuel 

consumption standards. The following criteria and restrictions apply to averaging, 

banking and trading FCC. 

(1) Averaging. Averaging is the exchange of FCC among a manufacturer’s engines or 

vehicle families or test groups within an averaging set. With the exception of FCC 

earned for advance technologies as further clarified below, a manufacturer may average 

FCC only within the same averaging set. The principle averaging sets are defined in § 

535.4.

(2) Banking. Banking is the retention of surplus FCC by the manufacturer generating the 

credits for use in future model years for averaging or trading. Banked FCC retain the 

designation from the averaging set and model year in which they were generated and 

expire after five model years.

(3) Trading. Trading is a transaction that moves FCC between manufacturers for 

averaging, banking, or further trading transactions. Traded FCC, other than advanced 

technology credits, may be used by a manufacturer only within the averaging set in which 
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they were generated. Entities other than manufacturers may only obtain traded FCC for 

the purpose of retiring them. 

* * * * *

14. Revise § 535.7 by amending section§ 535.7(b)(9), (c)(11)(i) and (d)(11)(i) to read as 

follows:

(b) * * *

(9) Calculate the value of credits generated in a model year for this regulatory 

subcategory or averaging set using the following equation:

Total MY Fleet FCC (gallons) = (Std -Act) × (Volume) × (UL) × (10-2)

Where:

Std = Fleet average fuel consumption standard (gal/100 mile).

Act = Fleet average actual fuel consumption value (gal/100 mile).

Volume = the total U.S.-directed production of vehicles in the regulatory subcategory.

UL = the useful life for the regulatory subcategory (120,000 miles).

* * * * *.

(c) * * *

(11) The value of credits generated in a model year is calculated as follows:

(i) Calculate the value of credits generated in a model year for each vehicle family or 

subfamily within an averaging set using the following equation:

Vehicle Family FCC (gallons) = (Std - FEL) × (Payload) × (Volume) × (UL) × (10-3)
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Where: 

Std = the standard for the respective vehicle family regulatory subcategory (gal/1000 

ton-mile). 

FEL = family emissions limit for the vehicle family or subfamily (gal/1000 ton-mile). 

Payload = the prescribed payload in tons for each regulatory subcategory as shown in 

the following table:

Regulatory subcategory Payload (Tons)

LHD Vocational Vehicles 2.85

MHD Vocational Vehicles 5.60

HHD Vocational Vehicles 7.5

Class 7 Tractor 12.50

Class 8 Tractor 19.00

Volume = the number of U.S. directed production volume of vehicles in the 

corresponding vehicle family.

UL = the useful life for the regulatory subcategory (miles) as shown in the 

following table:

Regulatory subcategory UL (miles)

LHD Vocational Vehicles 110,000

MHD Vocational Vehicles 185,000

HHD Vocational Vehicles 435,000

Class 7 Tractor 185,000

Class 8 Tractor 435,000

* * * * *.

(d) * * *

(11) The value of credits generated in a model year is calculated as follows:

(i) The value of credits generated in a model year for each engine family within a 

regulatory subcategory equals :

Engine Family FCC (gallons) = (Std - FCL) × (CF) × (Volume) × (UL) × (10-2)

Where: 
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Std = the standard for the respective engine regulatory subcategory (gal/100 bhp-hr). 

FCL = family certification level for the engine family (gal/100 bhp-hr).

CF= a transient cycle conversion factor in bhp-hr/mile which is the integrated total 

cycle brake horsepower-hour divided by the equivalent mileage of the applicable test 

cycle. For spark-ignition heavy-duty engines, the equivalent mileage is 6.3 miles. For 

compression-ignition heavy-duty engines, the equivalent mileage is 6.5 miles.

Volume = the number of engines in the corresponding engine family.

UL = the useful life of the given engine family (miles) as shown in the following 

table:

Regulatory Subcategory UL (miles)

Class 2b-5 Vocational Vehicles, Spark 

Ignited (SI), and Light Heavy-Duty Diesel 

Engines

110,000

Class 6-7 Vocational Vehicles and 

Medium Heavy-Duty Diesel Engines

185,000

Class 8 Vocational Vehicles and Heavy 

Heavy-Duty Diesel Engines

435,000

Regulatory Subcategory UL (miles)

Class 7 Tractors and Medium HeavyDuty Diesel Engines 185,000

Class 8 Tractors and Heavy Heavy-Duty 

Diesel Engines 

435,000

* * * * *

15. Revise § 535.7(e)(1)(i) and (ii) to read as follows:

(e) * * *

(1) * * *

(i) Heavy-duty vehicles. (A) This section specifies how to generate advanced 

technology-specific fuel consumption credits for hybrid vehicles, vehicles equipped with 

Rankine-cycle engines and fuel cell vehicles (or other vehicle specific advanced 
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technologies) for which the manufacturer is requesting a vehicle certificate from EPA. 

Calculate the advanced technology credits as follows:

(1) Determine the equivalent fuel consumption for hybrid systems with power take-off 

devices either from chassis or powertrain testing emissions rates derived in accordance 

with 40 CFR 1037.525. Determine the equivalent fuel consumption for hybrid systems 

with pre or post-transmissions and for vehicles with other non-hybrid advanced 

technology systems from chassis testing emissions rates derived in accordance with 40 

CFR 1037.550. Determine the equivalent fuel consumption in accordance with this 

paragraph unless EPA approves an alternative test procedure for the manufacturer. 

Measure the effectiveness of the advanced system by chassis testing a vehicle equipped 

with the advanced system and an equivalent conventional system in accordance with 40 

CFR 1037.525, 1037.550 and 1037.615.

(2) For purposes of this paragraph a conventional vehicle is considered to be equivalent if 

it has the same footprint, intended vehicle service class, aerodynamic drag, and other 

relevant factors not directly related to the advanced system powertrain. If there is no 

equivalent vehicle, the manufacturer may create and test a prototype equivalent vehicle. 

The conventional vehicle is considered Vehicle A, and the advanced technology vehicle 

is considered Vehicle B. 

(3) The benefit associated with the advanced system for fuel consumption is determined 

from the weighted fuel consumption results from the chassis tests of each vehicle using 

the following equation:
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Benefit (gallon/1000 ton mile) = Improvement Factor x GEM Fuel Consumption 

Result_B

Where:

Improvement Factor = (Fuel Consumption_A – Fuel Consumption_B)/(Fuel 

Consumption_A) 

Fuel Consumption Rates A and B are the gallons per 1000 ton-mile of the conventional 

and advanced vehicles, respectively as measured under the test procedures specified by 

EPA.

GEM Fuel Consumption Result B is the estimated gallons per 1000 ton-mile rate 

resulting from emission modeling of the advanced vehicle as specified in 40 CFR 

1037.520 and § 535.6(b).

(4) The manufacturer may apply the improvement factor to multiple vehicle 

configurations, if it uses the vehicle configuration with the smallest potential reduction in 

fuel consumption performance as a result of the hybrid capability.

(5) Calculate the benefit in credits using the equation in paragraph 535.7(c)(11) of this 

section and replacing the term (Std-FEL) with the benefit.

(B) For electric vehicles calculate the fuel consumption credits using an FEL of 0 

g/1000ton-mile.

* * * * *
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(ii) Heavy-duty engines. (A) This section specifies how to generate advanced 

technology-specific fuel consumption credits for hybrid engines and for engines that 

include Rankine-cycle (or other bottoming cycle) exhaust energy recovery systems for 

which the manufacturer is requesting an engine certificate from EPA. Calculate the 

advanced technology credits as follows: 

(1) Determine the equivalent fuel consumption for hybrid engine systems with features 

that recover and store energy during engine motoring operation from the emissions rates 

derived in accordance with 40 CFR 1036.525. 

(2) Determine the equivalent fuel consumption for hybrid pre-transmission powertrains 

that include energy storage systems and regenerative braking (including regenerative 

engine braking) and for engines that include Rankine-cycle exhaust energy recovery 

systems from the emissions rates derived in accordance with 40 CFR 1036.615. Hybrid 

pre-transmission powertrains are engine systems that include features that recover and 

store energy during engine motoring operation but not from the vehicle wheels. 

Determine the equivalent fuel consumption of hybrid engines in accordance with this 

paragraph unless EPA approves an alternative test procedure for the manufacturer.

* * * * *.

(B) Calculate credits as specified in paragraph (d) of this section. Credits generated from 

engines complying with this section may be used in other averaging sets as described in 

40 CFR 1036.740(d).

* * * * *

16. Revise § 535.8 by adding § 535.8 (a)(4) as follows:
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(a) * * * *

* * * * *

(4) Manufacturers submitting petitions for the off-road exemption in paragraph (h) should 

consider the timing to submit petitions early enough in advance of the model year to 

ensure that a determination can be made by the agencies and should a vehicle fail to be 

excluded, the manufacturer has sufficient time to submit and obtain approval from EPA 

for the certificate of conformity required in 40 CFR 1037.201 prior to first commercial 

sale of the vehicle.

* * * * *

17. Revise § 535.8 by amending § 535.8 (d) and (d)(2) to read as follows:

§ 535.8 Reporting requirements.

* * * * *

(d) End-of-the-Year-Report. Heavy-duty vehicle and engine manufacturers participating 

and not-participating in the ABT program are required to submit an end-of-the-year 

(EOY) report containing information for NHTSA as specified in paragraph (d)(2) and in 

accordance with 40 CFR 1036.250, 1036.730, 1037.104, 1037.250 and 1037.730. The 

EOY reports are used to review a manufacturer’s preliminary or final compliance 

information and to identify manufacturers that might have a credit deficit for the given 

model year. For model years 2013 and later, heavy-duty vehicle and engine 

manufacturers complying with NHTSA’s voluntary and mandatory standards must 

submit EOY reports through the EPA database including both GHG emissions and fuel 

consumption information for each given model year.
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* * * * *.

(2) Contents. Each EOY report must be submitted including the following fuel 

consumption information for each model year. EOY reports for manufacturers 

participating in the ABT program must include preliminary final estimates. EOY reports 

for manufacturers not participating in the ABT program and for heavy-duty pickup truck 

and van manufacturers must include finalized data. 

(i) Engine and vehicle family designations and averaging sets.

(ii) Engine and vehicle regulatory subcategory and fuel consumption standards including 

any alternative standards used.

(iii) Engine and vehicle family FCLs and FELs in terms of fuel consumption.

(iv) Production volumes for engines and vehicles.

(v) A credit plan (for manufacturers participating in the ABT program) identifying the 

manufacturers actual fuel consumption credit balances, credit flexibilities, credit trades 

and a credit deficit plan if needed demonstrating how it plans to resolve any credit 

deficits that might occur for a model year within a period of up to three model years after 

that deficit has occurred.

(vi) A final summary as specified in paragraph (h)(6) describing the vocational vehicles 

and vocational tractors that were exempted as heavy-duty off-road vehicles. This applies 

to manufacturers participating and not participating in the ABT program.

(vii) A summary describing any advanced or innovative technology engines or vehicles 

including alternative fueled vehicles that were produced for the model year identifying 

the approaches used to determinate compliance and the production volumes.
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(viii) A list of each unique subconfiguration included in a manufacturer’s fleet of heavyduty pickup trucks and vans identifying the attribute based-values (GVWR, GCWR, Curb 

Weight and drive configurations) and standards. This provision applies only to 

manufacturers producing heavy-duty pickup trucks and vans.

(ix) The fuel consumption fleet average standard derived from the unique vehicle 

configurations. This provision applies only to manufacturers producing heavy-duty 

pickup trucks and vans.

(x) The subconfiguration and test group production volumes. This provision applies only 

to manufacturers producing heavy-duty pickup trucks and vans.

(xi) The fuel consumption test group results and fleet average performance. This 

provision applies only to manufacturers producing heavy-duty pickup trucks and vans.

(xii) Under limited conditions, NHTSA may also ask a manufacturer to provide 

additional information directly to the Administrator if necessary to verify the fuel 

consumption requirements of this regulation.

* * * * *

18. Revise § 535.8 by amending § 535.8 (e) and (e)(2) as follows:

(e) Final reports. Manufacturers participating in the ABT program are required to submit 

year end final reports in accordance with 40 CFR 1036.730 and 1037.730 to NHTSA and 

EPA. Manufacturers of heavy-duty pickup trucks and vans are excluded from this 

requirement and are required to submit only one EOY report as specified in paragraph (d) 

of this section. The final reports are used to review a manufacturer’s final data and to 

identify manufacturers that might have a credit deficit for the given model year. For 
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model years 2013 and later, heavy-duty vehicle and engine manufacturers complying 

with NHTSA’s voluntary and mandatory standards must submit final reports through the 

EPA database including both GHG emissions and fuel consumption information for each 

given model year.

* * * * *

(2) Contents. Each final report must be submitted including the following fuel 

consumption information for each model year. 

(i) Final engine and vehicle family designations and averaging sets.

(ii) Final engine and vehicle fuel consumption standards including any alternative 

standards used.

(iii) Final engine and vehicle family FCLs and FELs in terms of fuel consumption.

(iv) Final production volumes for engines and vehicles.

(v) A final credit plan identifying the manufacturers actual fuel consumption credit 

balances, credit flexibilities, credit trades and a credit deficit plan if needed 

demonstrating how it plans to resolve any credit deficits that might occur for a model 

year within a period of up to three model years after that deficit has occurred 

(vi) A final plan describing any advanced or innovative technology engines or vehicles 

including alternative fueled vehicles that were produced for the model year identifying 

the approaches used to determinate compliance and the production volumes.

(vii) Under limited conditions, NHTSA may also ask a manufacturer to provide 

additional information directly to the Administrator if necessary to verify the fuel 

consumption requirements of this regulation.
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* * * * *
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Heavy-Duty Engine and Vehicle, and Nonroad Technical Amendments 

Dated: _______________________

_____________________________________________________

Ray LaHood, Secretary, Department of Transportation

Issued in Washington, DC on [March xx], 2013, under authority delegated in 49 CFR 

part 1.95
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Heavy-Duty Engine and Vehicle, and Nonroad Technical Amendments 

Dated: _______________________

_____________________________________________________

Bob Perciasepe, Acting Administrator, Environmental Protection Agency