1

May 2, 2013

MEMORANDUM

SUBJECT: Heavy-Duty Engine and Vehicle Greenhouse Gas Emissions and Fuel Consumption Regulatory 

Changes

FROM: Maurice Hicks, NHTSA

Angela Cullen, EPA

TO: Docket No. EPA-HQ-OAR-2012-0102 and NHTSA-2012-0152

NHTSA and EPA are making several corrections and adjustments to the regulations related to greenhouse gas 

(GHG) emission standards and fuel efficiency requirements for heavy-duty engines and vehicles. This memo is 

intended to assist readers in understanding the specific changes we are making. While we intend for the 

regulatory provisions in this memo to be identical to those published in the Federal Register, readers should 

understand that this is an unofficial version. Only the regulations published in the Federal Register are 

considered official for the public record or for public comment.

The revisions described in this memo generally affect the joint heavy-duty program (76 FR 57106). However, 

some of these amendments are unique to the rules of one or the other agency. Thus, this memo is divided 

into three sections. First is the set of amendments that directly affect both EPA’s and NHTSA’s regulations, 

which are discussed in Section A below. Next, the amendments exclusive to NHTSA’s regulations in 49 CFR 

parts 523 and 535 are included in Section B. Finally, EPA’s unique amendments in 40 CFR parts 85, 86, 1036, 

1037, 1065, and 1066, are discussed in Section C. 

A. Joint Heavy-Duty GHG and Fuel Efficiency Amendments

The joint amendments to the EPA and NHTSA regulatory provisions, as described in the preamble Section II.B, 

are contained in Table 1 below. This table contains a comparison of the EPA revised regulatory text sections 

and the parallel NHTSA sections.
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Table 1: Joint EPA/NHTSA Technical Amendments

Reason for Change Revised EPA Regulation Text Revised NHTSA Regulation Text 

The hybrid engine test 

procedures in 40 CFR 

1036.525 and 49 CFR 

535.7(e)(1 )(ii) refer to 

instructions which are only 

applicable to engine 

testing, not vehicle or 

powertrain testing.

§ 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. See 

§1036.615(a)(2) for engine systems intended to 

include features that recover and store energy 

from braking unrelated to engine motoring 

operation. For purposes of this section, 

features that recover energy between the 

engine and transmission are considered 

“related to engine motoring”.

§ 535.7(e) Additional credit provisions. (1)

Advanced technology credits.

(ii) Heavy-duty engines. (A) This section specifies 

how to generate advanced technology-specific fuel 

consumption credits for hybrid powertrains that 

include energy storage systems and regenerative 

braking (including regenerative braking) 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) Pre-transmission Determine the equivalent fuel 

consumption for hybrid powertrains are those 

engine systems that include with features that 

recover and store energy during engine motoring

operation but not from the vehicle wheels. These 

powertrains are tested using the hybrid engine test 

procedures of 40 CFR part 1065 or using the posttransmission test procedures from the emissions 

rates derived in accordance with 40 CFR 1036.525. 

(2) Post-transmission hybrid powertrains are those 

powertrains that include features that recover and 

store energy from braking at the vehicle wheels. 

These powertrains are tested by simulating the 

chassis test procedure applicable for hybrid vehicles 

under 40 CFR 1037.550.

(32) Test 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 

according to the test procedures specified in 40 CFR 

part 1036, subpart F, unless EPA approves the

manufacturer’s alternate procedures from the 

emissions rates derived in accordance with 40 CFR 

1036.615. Hybrid pre-transmission powertrains are 

those 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.
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Reason for Change Revised EPA Regulation Text Revised NHTSA Regulation Text 

Clarify that the post 

transmission hybrid test 

procedures can only be 

used for vehicle GHG 

certification.

§1036.615 Engines with Rankine cycle waste 

heat recovery and hybrid powertrains.

a) Hybrid powertrains. The following provisions 

apply for pre-transmission and posttransmission 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. Pretransmission 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.

(1) Pre-transmission hybrid powertrains are 

those engine systems that include features that 

recover and store energy during engine 

motoring operation but not from the vehicle 

wheels. These powertrains are tested using the 

hybrid test procedures of 40 CFR part 1065 or 

using the post-transmission test procedures in 

40 CFR 1037.550.

(2) Post-transmission hybrid powertrains are 

those powertrains that include features that 

recover and store energy from braking but that 

cannot function as hybrids without the 

transmission. These powertrains must have a 

single output shaft to the final drive and are 

tested by simulating the chassis test procedure 

applicable for hybrid vehicles under 40 CFR 

1037.550. You need our approval before you 

begin testing.

Changes above to 49 CFR 535.7(e)(1)(ii) address 

the issue.
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Reason for Change Revised EPA Regulation Text Revised NHTSA Regulation Text 

Clarify that 40 CFR 

1037.525 is applicable to 

either pre- or posttransmission hybrid 

architectures tested in a 

powertrain cell or in a 

vehicle chassis cell.

§ 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 so 

that all the energy is produced with the engine. 

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. These procedures may be used for 

whole vehicles, or with a post-transmission 

hybrid system. When testing just the posttransmission hybrid system, yYou 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 electricbattery hybrids, consistent with good 

engineering judgment.

§ 535.7(e) Additional credit provisions. (1)

Advanced technology credits.

(i) Heavy-duty vehicles. (A) This section specifies 

how to generate advanced technology-specific 

fuel consumption credits for advanced 

technology system (hybrid vehicles with 

regenerative braking, vehicles equipped, vehicles 

with Rankine-cycle engines and fuel cell vehicles

(or other vehicle specific advanced 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.

Clarify that 40 CFR 

1037.550 is applicable to 

either pre- or posttransmission hybrid 

architectures tested in a 

powertrain cell.

§ 1037.550 Special procedures for testing posttransmission hybrid systems. 

This section describes the procedure for 

simulating a chassis test with a pretransmission 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.

Change addressed above in 535.7(e)(i)(1)
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Reason for Change Revised EPA Regulation Text Revised NHTSA Regulation Text 

Apply the language from 

40 CFR 1037.550 to 40 CFR 

1037.615 which allows the 

application of an 

improvement factor or test 

result from a vehicle 

configuration with the 

smallest potential 

reduction in GHG 

emissions as a result of the 

hybrid system to be 

applied to multiple vehicle 

configurations.

§ 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 nonhybrid 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 

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. 

(3) (4) Use the equations of §1037.705 to 

convert the g/ton-mile benefit to emissions 

credits (in Mg). Use the g/ton-mile benefit in 

place of the (Std-FEL) term.

§ 535.7(e) Additional credit provisions. (1)

Advanced technology credits.

(i) Heavy-duty vehicles.

(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.

(4)(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.
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Reason for Change Revised EPA Regulation Text Revised NHTSA Regulation Text 

Clarify that the optional 

certification of certain 

vehicles to the standards 

of 40 CFR 1037.104 and 49 

CFR 535.5(a) are optionally 

extended to spark ignition 

complete and cabcomplete vehicles with a 

GVWR over 14,000 pounds 

and below 26,001 pounds 

(Class 4 through Class 6 

vehicles). 

§ 1037.150 Interim provisions.

(l) Optional certification under §1037.104. You 

may certify certain complete or cab-complete 

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 paragraph (l) does not allow 

you to chassis-certify these vehicles with 

respect to criteria pollutantsemissions.

(1) You may certify any complete or cabcomplete 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.

§ 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 incomplete cab-complete 

or complete vehicles having a GVWR over 14,000 

pounds and below 26,001 pounds equipped with 

a spark ignition engine as heavy-duty pickup 

trucks or vans or designate any spark ignition (or 

gasoline) engines certified and sold as a loose 

engines manufactured for use in a heavy-duty 

pickup trucks or vans. See references in 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.

§ 535.5(a) Heavy-duty pickup trucks and vans.

(6) Optional certification under this section. A

manufacturers 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

complete or cab-complete Class 2b

through 5 vehicles weighing at or below

19,500 pounds GVWR and any

incomplete vehicles approved by EPA for inclusion 

under this paragraph to the requirements

same testing and standards 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.

The agencies are clarifying 

how reporting 

requirements apply to 

heavy-duty pickup truck 

and van manufacturers 

and to simplify the 

§1037.104 Exhaust emission standards for CO2, 

CH4, and N2O for heavy-duty vehicles at or 

below 14,000 pounds.

(d)(15): You must submit a final report within 

90 days after the end of the model year. 

Unless we specify otherwise, include 

§ 535.8 (d) End-of-the-Year-Report. Heavy-duty 

vehicle and engine both manufacturers 

participating and not-participating in the ABT 

program are required to submit end-of-the-year 

(EOY) reports in accordance with 40 CFR 

1036.730 and 1037.730. an end-of-the-year (EOY) 
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Reason for Change Revised EPA Regulation Text Revised NHTSA Regulation Text 

reporting by eliminating 

the final report and 

requiring a single annual 

report due 90 days after 

the model year. The 

requirements for the 

annual report were 

included in 40 CFR 

86.1865-12(l) in the 

original regulations. 

NHTSA is modifying its 

regulation to harmonize

with EPA provisions.

applicable information identified in 40 CFR 

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.

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.

(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. 

(vi) A plan 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 final plan 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.

(viii) A final list of each unique subconfiguration 

included in a manufacturers fleet of heavy-duty

pickup trucks and vans describing the

designations, 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 final fuel consumption fleet average 

standard derived from the unique vehicle 
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Reason for Change Revised EPA Regulation Text Revised NHTSA Regulation Text 

configurations. This provision applies only to 

manufacturers producing heavy-duty pickup 

trucks and vans.

(x) The preliminary final subconfiguration and test 

group production volumes. This provision applies 

only to manufacturers producing heavy-duty 

pickup trucks and vans.

(xi) The preliminary final fuel consumption test 

group results and fleet average performance. This 

provision applies only to manufacturers producing 

heavy-duty pickup trucks and vans.

The existing definitions for 

“configuration” and 

“subconfiguration,” 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. 

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. 

§ 1037.104 Exhaust emission standards for CO2, 

CH4, and N2O for heavy-duty vehicles at or 

below 14,000 pounds GVWR.

(d) (12) The following definitions apply for the 

purposes of this section:

(i) 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 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 

the drive system of the vehicle (e.g., frontwheel drive, rear-wheel drive, or four-wheel 

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 definition 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.

§ 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 four-wheel drive). Engine code means 

the combination of both “engine code” and 

“basic engine” as defined in the provisions of 40 

CFR 600.002. 

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 standards, equivalent test weight 

(ETW) is based on the ALVW of the vehicle as 

outlined in paragraph 40 CFR 1037.104(d)(11).
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Reason for Change Revised EPA Regulation Text Revised NHTSA Regulation Text 

Clarify that the vocational 

tractors should be certified 

as part of the vocational 

regulatory subcategory 

that applies to their weight 

class as stated in 40 CFR

1037.630(b)(2).

§ 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 than 26,000

pounds GVWR.

(xiv) Vocational tractors above 33,000 pounds 

GVWR.

§ 535.5(c) Truck tractors.

(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 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.

B. NHTSA-Only Fuel Efficiency Technical Amendments

The unique amendments for the NHTSA program, as described in Section II.C of the preamble to the rule, are 

contained in Table 2. This table contains a comparison of the existing EPA and the revised NHTSA regulatory 

text sections.

Table 2: NHTSA-Only Technical Amendments

Reason for Change Existing EPA Regulation Text Revised NHTSA Regulation Text

NHTSA to clarify that 

second stage 

manufacturers can be 

certificate holders and 

ultimately credit 

holders as per 40 CFR 

1037.620. "Shipment 

of Incomplete 

Vehicles." This 

requirement covers 

§ 1037.620 Shipment of incomplete vehicles to 

secondary vehicle manufacturers.

(a) The provisions of this section allow 

manufacturers to ship partially complete vehicles 

to secondary vehicle manufacturers or otherwise 

introduce them into U.S. commerce in the 

following circumstances:

(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 

§ 535.3(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. 

§ 535.3(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 
10

Reason for Change Existing EPA Regulation Text Revised NHTSA Regulation Text

uncertified vehicles 

that will be certified 

by second stage 

manufacturers.

paragraph (b) of this section.

(b) The provisions of this paragraph (b) generally 

apply where the secondary vehicle manufacturer 

has substantial control over the design and 

assembly of emission controls. In determining 

whether a manufacturer has substantial control 

over the design and assembly of emission 

controls, we would consider the degree to which 

the secondary manufacturer would be able to 

ensure that the engine and vehicle will conform 

to the regulations in their final configurations.

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.

§ 535.7(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 (hereafter reference as the 

NHTSA ABT program). 

NHTSA is adding a 

definition in 49 CFR 

535.4 for “credit 

holder” and adding 

requirements in 49 

CFR part 535.7 to 

clarify the limitations 

for nonmanufacturers to 

obtain and trade fuel 

consumption credits. 

These additions are 

made to parallel the 

EPA requirements in 

40 CFR 1036.701(h), 

1036.720(a), 

1037.701(e), and 

1037.720(a).

§ 1036.701 General provisions.

(h) You may trade emission credits generated 

from any number of your engines to the engine 

purchasers or other parties to retire the credits. 

Identify any such credits in the reports described 

in § 1036.730. Engines must comply with the 

applicable FELs even if you donate or sell the 

corresponding emission credits under this 

paragraph (h). Those credits may no longer be 

used by anyone to demonstrate compliance with 

any EPA emission standards.

§ 1037.701 General provisions.

(e) You may trade emission credits generated 

from any number of your vehicles to the vehicle 

purchasers or other parties to retire the credits. 

Identify any such credits in the reports described 

in § 1037.730. Vehicles must comply with the 

applicable FELs even if you donate or sell the 

corresponding emission credits under this 

paragraph (e). Those credits may no longer be 

used by anyone to demonstrate compliance with 

any EPA emission standards.

§ 535.4 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 non-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). 
11

Reason for Change Existing EPA Regulation Text Revised NHTSA Regulation Text

Same issue as above §§ 1036.720 and 1037.720 Trading.

(a) Trading is the exchange of emission credits 

between manufacturers, or the transfer of 

credits to another party to retire them. You may 

use traded emission credits for averaging, 

banking, or further trading transactions. Traded 

emission credits remain subject to the averagingset restrictions based on the averaging set in 

which they were generated.

§ 535.7(a)(3) Trading. Trading is a transaction that 

moves FCC between manufacturers for averaging, 

banking, or further trading transactions. A 

manufacturer may use traded FCC 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 they were generated. Entities other than 

manufacturers may only obtain traded FCC for the 

purpose of retiring them. 

NHTSA is adding 

interim provisions for 

heavy-duty pickup 

trucks and vans for 

model years prior to 

2015 from EPA’s 

requirements in 40 

CFR 1037.150 that 

were inadvertently 

omitted in the final 

rule.

§ 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 than 

electric vehicles, you must certify your entire 

U.S.-directed production volume within the 

regulatory sub-category to these standards. 

Except as specified in paragraph (a)(4) of this 

section, if some vehicle families within a 

regulatory subcategory are certified after the 

start of the model year, you may generate 

credits only for production that occurs after all 

families are certified.

(g) Compliance date. Compliance with the 

standards of this part is optional prior to January 

1, 2014. This means that if your 2014 model year 

begins before January 1, 2014, you may certify 

for a partial model year that begins on January 1, 

2014 and ends on the day your model year 

would normally end...

§ 535.5(a) Heavy-duty pickup trucks and vans.

(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) in 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). 

(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).
12

Reason for Change Existing EPA Regulation Text Revised NHTSA Regulation Text

NHTSA is adding 

interim provisions for 

Class 2b-8 vocational 

vehicles for model 

years prior to 2015 

from EPA’s 

requirements in 40 

CFR 1037.150 that 

were inadvertently 

omitted in the final 

rule.

§1037.150 Interim provisions.

(a)(1) This paragraph (a)(1) applies for regulatory 

sub-categories subject to the standards of § 

1037.105 or § 1037.106.

Except as specified in paragraph (a)(3) of this 

section, to generate early credits under this 

paragraph for any vehicles other than electric 

vehicles, you must certify your entire U.S.-

directed production volume within the 

regulatory sub-category to these standards... 

Except as specified in paragraph (a)(4) of this 

section, if some vehicle families within a 

regulatory subcategory are certified after the 

start of the model year, you may generate 

credits only for production that occurs after all 

families are certified.

(g) Compliance date. Compliance with the 

standards of this part is optional prior to January 

1, 2014. This means that if your 2014 model year 

begins before January 1, 2014, you may certify 

for a partial model year that begins on January 1, 

2014 and ends on the day your model year 

would normally end...

§ 535.5(b). Heavy-duty vocational vehicles.

(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 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). 
13

Reason for Change Existing EPA Regulation Text Revised NHTSA Regulation Text

NHTSA is adding 

interim provisions for 

tractors for model 

years prior to 2015 

from EPA’s 

requirements in 40 

CFR 1037.150 that 

were inadvertently 

omitted in the final 

rule.

§1037.150 Interim provisions.

(a)(1) This paragraph (a)(1) applies for regulatory 

sub-categories subject to the standards of § 

1037.105 or § 1037.106.

Except as specified in paragraph (a)(3) of this 

section, to generate early credits under this 

paragraph for any vehicles other than electric 

vehicles, you must certify your entire U.S.-

directed production volume within the 

regulatory sub-category to these standards... 

Except as specified in paragraph (a)(4) of this 

section, if some vehicle families within a

regulatory subcategory are certified after the 

start of the model year, you may generate 

credits only for production that occurs after all 

families are certified.

(g) Compliance date. Compliance with the 

standards of this part is optional prior to January 

1, 2014. This means that if your 2014 model year 

begins before January 1, 2014, you may certify 

for a partial model year that begins on January 1, 

2014 and ends on the day your model year 

would normally end...

§ 535.5 (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 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). 
14

Reason for Change Existing EPA Regulation Text Revised NHTSA Regulation Text

NHTSA needs to clarify 

that manufacturers 

not participating and 

participating in the 

ABT program must 

submit EOY reports 90 

days after the model 

year. 

§ 1037.250 Reporting and recordkeeping. 

(a) Within 90 days after the end of the model 

year, send the Designated Compliance Officer a 

report including the total U.S.-directed 

production volume of vehicles you produced in 

each vehicle family during the model year (based 

on information available at the time of the 

report). Report by vehicle identification number 

and vehicle configuration and identify the 

subfamily identifier. Report uncertified vehicles 

sold to secondary vehicle manufacturers. Small 

manufacturers may omit the reporting 

requirements of this paragraph (a).

§ 1037.730 ABT reports. 

(a) If any of your vehicle families are certified 

using the ABT provisions of this subpart, you 

must send an end-of-year report within 90 days 

after the end of the model year and a final report 

within 270 days after the end of the model year.

§ 535.8(d) End-of-the-Year-Report. Heavy-duty 

vehicle and engine manufacturers participating and 

not-participating in the ABT program are required to 

submit year end reports; an end-of-the-year (EOY) 

reports 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.
15

Reason for Change Existing EPA Regulation Text Revised NHTSA Regulation Text

NHTSA needs to clarify 

that EOY reports 

contain preliminary 

final estimates for 

manufacturers 

participating in the 

EPA ABT program and 

finalized data for nonparticipating 

manufacturers as well 

as for Class 2b-3 

manufacturers.

(76 FR 57262 ) The EOY report is used by the 

agencies to review a manufacturer’s preliminary 

final estimates and to identify manufacturers 

that might have a credit deficit for the given 

model year.

§535.8(d) End-of-the-year-report.

(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 must include preliminary 

final estimates. EOY reports for manufacturers not 

participating in the ABT and for heavy-duty pickup 

truck and van manufacturers must include finalized 

data.

(vii) A final summary 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.

(viii) A final list of each unique subconfiguration 

included in a manufacturers fleet of heavy-duty 

pickup trucks and vans describing the designations,

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 final 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 preliminary final subconfiguration and test 

group production volumes. This provision applies 

only to manufacturers producing heavy-duty pickup 

trucks and vans.

(xi) The preliminary final fuel consumption test group 

results and fleet average performance. This provision 

applies only to manufacturers producing heavy-duty 

pickup trucks and vans.
16

Reason for Change Existing EPA Regulation Text Revised NHTSA Regulation Text

NHTSA needs to clarify 

that manufacturers 

participating in the 

ABT program must 

submit final reports 

270 days after the 

model year. 

§ 1037.730 ABT reports. 

(a) If any of your vehicle families are certified 

using the ABT provisions of this subpart, you 

must send an end-of-year report within 90 days 

after the end of the model year and a final report 

within 270 days after the end of the model year.

§535.8(e) Final reports. Both Manufacturers 

participating and not 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 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.

(vi) A final plan describing the vocational vehicles and 

vocational tractors that were exempted as heavy-duty 

off-road vehicles.

(vii) 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.

(viii) A final list of each unique subconfiguration 

included in a manufacturers fleet of heavy-duty pickup 

trucks and vans describing the designations, 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 final 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 final subconfiguration and test group production 

volumes. This provision applies only to manufacturers 

producing heavy-duty pickup trucks and vans.

(xi) The final fuel consumption test group results and 

fleet average performance. This provision applies only 

to manufacturers producing heavy-duty pickup trucks 

and vans.

(xvii) 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.
17

Reason for Change Existing EPA Regulation Text Revised NHTSA Regulation Text

NHTSA needs to clarify 

when petitions for HD 

off-road vehicles 

should be submitted 

to review.

None § 535.8 (a) General requirements.

(4) Manufacturers submitting petitions for the offroad 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.

NHTSA needs to clarify 

that the plan for HD 

off-road vehicles must 

be submitted for 

participating and nonparticipating ABT 

manufacturers in the 

EOY reports 90 days 

after the model year 

ends.

§ 1037.631 Exemption for vocational vehicles 

intended for off-road use. 

(c) Recordkeeping and reporting. (1) You must 

keep records to document that your exempted 

vehicle configurations meet all applicable 

requirements of this section. Keep these records 

for at least eight years after you stop producing 

the exempted vehicle model. We may review 

these records at any time.

(2) You must also keep records of the individual 

exempted vehicles you produce, including the 

vehicle identification number and a description 

of the vehicle configuration.

(3) Within 90 days after the end of each model 

year, you must send to the Designated 

Compliance Officer a report with the following 

information:

(i) A description of each exempted vehicle 

configuration, including an explanation of why it 

qualifies for this exemption.

(ii) The number of vehicles exempted for each 

vehicle configuration.

§535.8(d) End-of-the-year-report.

(vi) A plan final summary as specified in paragraph 

(h)(6) describing the vocational vehicles and 

vocational tractors that were exempted as heavyduty off-road vehicles. This applies to manufacturers 

participating and not participating in the ABT 

program.
18

Reason for Change Existing EPA Regulation Text Revised NHTSA Regulation Text

NHTSA needs to 

correct a reference in 

49 CFR 535.5(c)(5) to 

EPA’s vocational 

tractor requirements 

in 40 CFR 1037.630.

§ 1037.630 Special purpose tractors.

(a) General provisions. This section allows a 

vehicle manufacturer to reclassify certain 

tractors as vocational tractors. Vocational 

tractors are treated as vocational vehicles and 

are exempt from the standards of § 1037.106. 

Note that references to ‘‘tractors’’ outside of this 

section mean non-vocational tractors.

§535.5(c) Applications for certificate of conformity.

(5) Tractors meeting the definition of vocational 

tractors in 49 CFR 523.2 must comply with 

requirements for heavy-duty vocational vehicles 

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 40 CFR 1037.610 1037.630, a 

manufacturer must comply with the tractor fuel 

consumption standards in paragraph (3) of this 

section. 

NHTSA needs to clarify 

how to convert EPA 

CO2 values to 

equivalent fuel 

consumption values to 

ensure 

standardization 

between the agencies 

when selecting vehicle 

families for vocational 

vehicles and tractors 

based upon subfamily 

FEL values. 

None §535.6(b) Heavy-duty vocational vehicles and 

tractors.

(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. 
19

Reason for Change Existing EPA Regulation Text Revised NHTSA Regulation Text

NHTSA needs to 

correct minor 

technical errors in its 

equations for 

calculating fuel 

consumption credits 

in 49 CFR 535.7 to 

make them equivalent 

to EPA’s GHG credits. 

§ 86.1865–12 How to comply with the fleet 

average CO2 standards.

(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 and light trucks, the number of 

credits or debits it has generated according to 

the following equation, rounded to the nearest 

megagram:

CO2 Credits or Debits (Mg) = [(CO2 Standard—

Manufacturer’s Production- Weighted Fleet 

Average CO2 Emissions) × (Total Number of 

Vehicles Produced) × (Vehicle Lifetime Miles)] ÷ 

1,000,000

Where:

CO2 Standard = the applicable standard for the 

model year as determined by § 86.1818–

12; Manufacturer’s Production-Weighted Fleet 

Average CO2 Emissions = average calculated 

according to paragraph (i) of this section; Total 

Number of Vehicles Produced = The number of 

vehicles domestically produced plus those 

imported as defined in § 600.511 of this chapter.

§ 1036.705 Generating and calculating emission 

credits.

(b)(1) and (2) 

For tractor (and vocational ) engines:

Emission credits (Mg) = (Std-FCL) ·(CF) · (Volume) 

· (UL) · (10-6)

§ 1037.705 Generating and calculating emission 

credits.

(b)(1) and (2) 

For vocational vehicles (and tractors):

Emission credits (Mg) = (Std-FEL) × (Payload 

Tons) × (Volume) × (UL) × (10-6)

Where:

Std = the emission standard associated with the 

specific vocational vehicle or tractor regulatory 

subcategory (g/ton-mile).

FEL = the family emission limit for the vehicle 

subfamily (g/ton-mile).

§535.7(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)

535.7(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)

FEL = family emissions limit for the vehicle family or 

subfamily (gal/1000 ton-mile). 

535.7(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)
20

C. EPA’s Heavy-Duty GHG Technical 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. 

EPA is revising portions of the regulations in 40 CFR part 1036 to correct technical errors, as discussed in 

Section II.D.1 of the preamble to the rule. Table 3 summarizes the changes to the heavy-duty engine 

regulations.

Table 3: EPA Regulatory Changes to 40 CFR Part 1036

Reason for Change Revised Regulation Text

40 CFR 1037.103 does not exist. § 1036.5 Which engines are excluded from this part’s requirements?

(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, such as the evaporative emission requirements of 40 

CFR 1037.103.

The regulatory text referenced the incorrect 

regulatory citation for the label.

§ 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 vehicles engines with the statement: “THIS ENGINE IS EXCLUDED UNDER 

1037.150(c) §1036.150(d).” 

The assigned DF should contain an additional 

significant figure.

§ 1036.150 Interim provisions. 

(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.
21

Reason for Change Revised Regulation Text

To clarify that CH4 and N2O emission 

standards apply to all testable 

configurations.

§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 total 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 total 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 least 31 engines 

meets the FCL. Where applicable, also identify other testable configurations 

required under §1036.230(b)(2).

40 CFR 1036.135 does not require that the 

FEL for CO2 be included on the ECI label. 

Thus, §1036.225 should not require this 

labeling requirement either.

§ 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). If we approve a changed FEL after the start 

of production, you must include the new FEL on the emission control information 

label for all engines produced after the change. You may ask us to approve a change 

to your FEL in the following cases:

Correct the regulation citation in to 40 CFR 

1036.740.

§1036.615 Engines with Rankine cycle waste heat recovery and hybrid powertrains.

(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(d) (c).

To add a definition of “preliminary 

approval.”

§ 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.

EPA is also revising portions of the regulations in 40 CFR part 1037 to correct technical errors. Table 4

summarizes the changes to the heavy-duty vehicle regulations that are discussed in the preamble Section 

II.D.2.

Table 4: EPA Regulatory Changes to 40 CFR Part 1037

Reason for Change Revised Regulation Text

Clarify the provisions of 40 CFR 86.1865-12 

which apply to vehicles subject to 40 CFR

1037.104.

§ 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, applyies for 

vehicles subject to §1037.104; including the following paragraphs of 86.1865-

12: (a), (h)(1), (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).
22

Reason for Change Revised Regulation Text

Clarify that the standards in 40 CFR

1037.104(a)(2) represent the final target 

values and that the phase-in provisions in 40 

CFR 1037.150(b) also apply.

§ 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:

Clarify the credit provisions for vehicles subject 

to 40 CFR 1037.104.

§ 1037.104 Exhaust emission standards for CO2, CH4, and N2O for heavy-duty 

vehicles at or below 14,000 pounds GVWR.

(d)(2) The following general credit provisions apply:

(i) Credits you generate under this section may be used only to offset deficits 

under this section. You may bank credits for use in a future model year in 

which your average 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. 

(2)(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.

The light-duty N2O and CH4 standards only 

apply to the city cycle. Deletion of this text will 

remove any question concerning the 

difference between the heavy-duty and lightduty programs.

§ 1037.104 Exhaust emission standards for CO2, CH4, and N2O for heavy-duty 

vehicles at or below 14,000 pounds GVWR.

(d)(4) The CO2, N2O, and CH4 standards apply for a weighted average of the city 

(55%) and highway (45%) test cycle results as specified for light-duty vehicles in 

40 CFR part 86, subpart S. Note that this differs from the way the criteria 

pollutant standards apply for heavy-duty vehicles.

Clarify the credit provisions for vehicles subject 

to 40 CFR 1037.104.

§ 1037.104 Exhaust emission standards for CO2, CH4, and N2O for heavy-duty 

vehicles at or below 14,000 pounds GVWR.

(d)(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).

Clarify the method of calculating the fleet 

average CO2 value for heavy-duty vehicles 

subject to the standards of 40 CFR 1037.104. 

This technical amendment aligns the process 

described in the preamble to the final rules (76 

FR 57258) with the regulations.

§ 1037.104 Exhaust emission standards for CO2, CH4, and N2O for heavy-duty 

vehicles at or below 14,000 pounds GVWR.

(d)(9)

(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), 
23

Reason for Change Revised Regulation Text

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) At least 90 percent of 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.

(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.

Update the reference to 40 CFR part 86 to 

reflect the regulation changes made in the 

2017-2025MY Light Duty Vehicle Greenhouse 

Gas Emissions and Fuel Economy Rule.

§ 1037.104 Exhaust emission standards for CO2, CH4, and N2O for heavy-duty 

vehicles at or below 14,000 pounds GVWR.

(d)(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 86.1866-12(d) 86.1869-12(c) and (d).

You do not need to provide justification for not using the 5-cycle methodology 

option.

Clarify the certification test procedure for 

heavy-duty pickup truck s and vans.

§ 1037.104 Exhaust emission standards for CO2, CH4, and N2O for heavy-duty 

vehicles at or below 14,000 pounds GVWR.

(g)(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 judgement. 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 
24

Reason for Change Revised Regulation Text

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 changes in future CO2 emission levels. Any EPA guidance 

document will determine the model year 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 is 

January 2, 2013, so guidance would be issued by May 1, 2012 for model year 

2014. 

(3) You may select, without our prior advance approval, baseline test data that 

if they meet all the following criteria:

(i) Vehicles considered for selection 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 which will be 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 standards.

(iii).....

(iv) Except with our advance approval, tests previously used during the subject 

model year as baseline tests in ten 20 other ADC subconfigurations must be 

eliminated from the pool. 

(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. 

(7) No more than 40 percent of the subconfigurations tested in your final CO2 

submission may be represented by ADCs. [Reserved]

(8) Keep the following records for at least five years, and show them to us if 

we ask to see them:

(i) You must retain for five years tThe pool of tests.,

(ii) The vehicle description and tests chosen as the baseline and the basis for its

the selection.,

(iii) The target ADC subconfiguration., and

(iv) The calculated emission rates. We may ask to see these records at any time.

(9) ....

(10) Where we determine that you did not fully comply with the provisions of 

this paragraph (g), we may rescind the use of ADC data , require that you 

comply based on generation of actual test data and that you recalculate

require recalculation of your fleet-average emission rate.
25

Reason for Change Revised Regulation Text

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.

The procedure for determining the HFC 

leakage rate for air conditioning systems with 

alternate refrigerants is addressed in SAE 

J2727, which is incorporated by reference in 40 

CFR 86.1. 

§ 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 paragraphs

(c)(2) and (3) of this section. Calculate the total leakage rate in g/year as 

specified in 40 CFR 86.166 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.

(2) [Reserved]

If your system uses a refrigerant other than HFC–134a, adjust your leakage rate 

by multiplying it by the global warming potential of your refrigerant and dividing 

the product by 1430 (which is the global warming potential of HFC–134a). 

Apply this adjustment before comparing your leakage rate to the standard. 

Determine global warming potentials consistent with 40 CFR 86.1866. Note 

that global warming potentials represent the equivalent grams of CO2 that 

would have the same global warming impact (over 100 years) as one gram of 

the refrigerant.

Revise the regulation such that the date of 

manufacture for the vehicle is allowed to be 

identified on the vehicle, not the engine.

§ 1037.135 Labeling.

(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 engine vehicle, in which case you must also 

describe in your application for certification where you will identify the date on 

the engine vehicle.

Clarify that this labeling requirement only 

applies to vehicles with liquid fuel and which 

use a canister.

§ 1037.135 Labeling.

(c)(9) Include the following statement for vehicles with an evaporative canister

for controlling diurnal emissions if applicable: “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.

Adjust the language in § 1037.150 to be 

consistent to the preamble to the final rule (76 

FR at 57245) which stipulates that the entire 

heavy-duty pickup truck and van fleet must be 

certified to qualify for early credits.

§ 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 than electric vehicles, you must certify your entire U.S.-

directed production volume within the regulatory sub-category 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 

regulatory sub-category 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 production in any of the test 

groups that occurs 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 EPA us of your 

intent to use this provision before submitting your applications.
26

Reason for Change Revised Regulation Text

To clarify that this requirement applies to 

vehicles used to determine Falt-aero under 40 

CFR 1037.521.

§ 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.

Trailers do not exist in production today that 

meet the rear axle position specified in the 

regulations. The revised text corrects the 

language such that it represents the 

appropriate trailer dimension.

§ 1037.501 General testing and modeling provisions.

(g)(1) The standard trailer for high-roof tractors must meet the following 

criteria: 

(iv) It includes dual 22.5 inch wheels, standard mudflaps, and standard landing 

gear. The centerline of the rear-most tandem axle must be 146 +/- 4 inches 

from the rear of the trailer.

Fix typographical error. § 1037.520 Modeling CO2 emissions to show compliance.

This section describes how to use the GEM 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.

(e)(1) Vehicle weight reduction inputs for wheels are specified relative to dualwide tires with conventional steel wheels. For purposes of this paragraph (e)(1),

a light-weight aluminum wheel is one that weighs at least 21 lb pounds less 

than a comparable conventional steel wheel. The inputs are listed in Table 34

to this section. For example, a tractor with aluminum steel steer wheels and 

eight (4x2) dual-wide aluminum drive wheel would have an input of 210 lbs

pounds (2x21 =+ 8x21). 

Change the nomenclature of the vehicle speed 

variable from S to v to be consistent with 40 

CFR part 1065.

Remove the torque control option because it 

causes testing issues when the vehicle is 

shifting and braking. In addition, removing one 

of the two dynamometer control modes 

reduces lab-to-lab variability.

§ 1037.550 Special procedures for testing post-transmission hybrid systems.

Changes detailed in the regulations published in the Federal Register make 

modifications to (d), (e), and (f) related to the vehicle speed variable 

nomenclature and the removal of the torque control option for running the 

test.

Clarify the regulatory text for instances where 

the secondary manufacturer who would hold 

the vehicle GHG certificate, may be a small 

business that would be exempted from the 

GHG regulations.

§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).
27

Reason for Change Revised Regulation Text

Similar to the reasons which supported the 

development of vehicle speed limiter 

flexibilities, an automatic engine shutdown 

(AES) system can be developed to alleviate 

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 APUs, that 

malfunction and necessitate extended idling. 

A remedy to these concerns would be to 

design the AES such that it allows for a 

predetermined number of hours per year of 

idling. The addition to 40 CFR 1037.660 

appropriately quantifies the CO2 emissions and 

fuel consumption of a partial AES system 

through the discounting of the AES input to 

GEM. 

§ 1037.660 Automatic engine shutdown systems.

This section specifies requirements that apply for certified automatic engine 

shutdown (AES) systems (AES) that are modeled under §1037.520. It does not 

apply for AES systems you do not model under §1037.520.

(c) Expiration Adjustments of 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 expiring 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 using 

the following equation rounded to the nearest 0.1 g/ton-mile: 

AES Input = 5 g CO2/ton-mile × (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. 

This new provision clarifies manufacturers’ 

liability for offsetting debits (or deficit credits) 

after certifying with emissions above the 

standards for three years. We would 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 

which allow debits to be carried forward a 

given number of model years and are later 

offset with credits (40 CFR 86.1861-04(e), 

86.1864-1(o), and 86.1865-12(k)). 

§ 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.

To add a definition of “preliminary approval.” § 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.
28

Reason for Change Revised Regulation Text

Revise the regulatory text so that it matches 

the definition of “Class” in 40 CFR 1037.801 

and is consistent with DOT’s Gross Vehicle 

Weight Rating Classes in 49 CFR 565.15, Table 

II. Also, aggregate the heavy-duty pickup 

truck and van sub-category to match the 

definition in 49 CFR 535.4.

§ 1037.801 Definitions.

Regulatory Sub-category

(1) Spark-ignition 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) All other vehicles subject to the standards of §1037.104. Note that this 

category includes most diesel-fueled heavy-duty pickup trucks and vans.

[Reserved]

(3) Vocational vehicles at or below 19,500 pounds GVWR.

(4) Vocational vehicles at or above 19,500 pounds GVWR but at or below 33,000 

pounds GVWR. 

(5) Vocational vehicles over 33,000 pounds.

(6) Low-roof tractors at or above 26,000 pounds GVWR but at or below 33,000 

pounds GVWR. 

(7) Mid-roof tractors at or above 26,000 pounds GVWR but at or below 33,000 

pounds GVWR. 

(8) High-roof tractors at or above 26,000 pounds GVWR but at or below 33,000 

pounds GVWR. 

(9) Low-roof day cab tractors at or above 33,000 pounds GVWR. 

(10) Low-roof sleeper cab tractors at or above 33,000 pounds GVWR. 

(11) Mid-roof day cab tractors at or above 33,000 pounds GVWR.

(12) Mid-roof sleeper cab tractors at or above 33,000 pounds GVWR.

(13) High-roof day cab tractors at or above 33,000 pounds GVWR. 

(14) High-roof sleeper cab tractors at or above 33,000 pounds GVWR. 

EPA is also revising portions of the regulations in 40 CFR parts 1065 and 1066 to clarify test procedures, as 

discussed in Section II.D.4 of the preamble to the rule. Table 5 summarizes the changes to the regulations.

Table 5: EPA Regulatory Changes to 40 CFR Parts 1065 and 1066

Reason for Change Revised Regulation Text

Restore text to 40 CFR 

1065.610(c)(3)(i) through (iii) which 

was inadvertently removed in the C3 

Marine Final Rule (75 FR 22896, April 

30,2010).

§ 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.
29

Reason for Change Revised Regulation Text

Clarify the vehicle speed range for 

coastdown testing and the 

anemometer calibration procedure.

§ 1066.310 Coastdown procedures for heavy-duty vehicles.

(b) (2) You must reach a top speed of greater than 70 mph such thatdata colletion of the 

coastdown can start at or above 70 mph. 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. Data analysis for valid coastdown 

runs must include a maximum speed of 70 mph 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) Run the zero-wind and zero-angle calibration data collection. 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] (ii) The anemometer must have had its outputs recorded at a wind speed of 

0.0 mph within 24 hours before each coastdown test in which it is used.

(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 each direction. You may use coastdown run times that do not 

meet these standard deviation requirements if we approve it in advance. In your 

request, describe why the vehicle is not able to meet the specified standard deviation 

requirements and propose an alternative set of requirements.

(7) Analyze data for chassis and post-transmission powerpack testing or for use in the 

GEM simulation tool as follows:

(i) Follow the procedures specified in Section 10 of SAE J1263 or Section 11 of SAE J2263 

to calculate coefficients for chassis and post-transmission powerpack testing.

(ii) For the GEM simulation tool, determine drag area, CDA, as follows instead of using the 

procedure specified in Section 10 of SAE J1263:

As discussed in Section II.D.5 of the preamble to the rule, EPA is also revising portions of the regulations in 40 

CFR part 85 to clarify the applicable standards for fuel conversions. Table 6 summarizes the changes to the 

regulations.

Table 6: EPA Regulatory Changes to 40 CFR Part 85

Reason for Change Revised Regulation Text

Provide clarity regarding the 

applicability of the fuel conversion 

regulations to heavy-duty pickup 

trucks and vans.

§ 85.525 Applicable standards.

(a)(2) (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 is 

demonstrated by complying with the N2O and CH4 standards and provisions set forth in 
30

Reason for Change Revised Regulation Text

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 the Federal Test Procedure (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 post-conversion sum of these emissions must be lower than the preconversion greenhouse gas emission result. Calculate CO2 emissions as specified in 40 

CFR 600.113-12. If we waived N2O measurement requirements based on a statement of 

compliance from the OEM, disregard N2O for all measurements and calculations under 

this paragraph (a)(2)(iii)(C).

EPA is also revising portions of the regulations in 40 CFR part 86 to clarify test procedures and reporting 

requirements, as discussed in Section II.D.6 of the preamble to the rule. Table 7 summarizes the changes to 

the regulations.

Table 7: EPA Regulatory Changes to 40 CFR Part 86

Reason for Change Revised Regulation Text

Provide a mechanism for engine 

manufacturers to identify engines 

which are only suitable for 

installation in hybrid applications.

§ 86.010-18 On-board Diagnostics for engines used in applications greater than 14,000 

pounds GVWR.

(q) Optional phase-in for hybrid vehicles.

(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".

Clarify that portions of 40 CFR part 86 

apply to the heavy-duty pickup trucks 

and vans subject to 40 CFR 1037.104.

§ 86.1865-12 How to comply with the fleet average CO2 standards.

(a) Applicability

(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.
31

Reason for Change Revised Regulation Text

(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 emissions levels of passenger automobiles, light trucks, and heavy-duty vehicles, as 

applicable, are at or below the applicable fleet average standards; or

(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: 

(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 §86.614for light-duty vehicles 

or §86.1014-84 for light-duty trucks and, if a manufacturer requests such a hearing, will be 

made only after an initial decision by the Presiding Officer.

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. The reporting 

requirement should have been 

removed with the rule to adopt those 

standards.

Remove §§86.007-23(n) and 86.1844-01(j) which describe how to report CO2, N2O, and 

CH4 emissions.