Environmental Protection Agency 

40 CFR Chapter I 

For the reasons set forth in the preamble, the Environmental Protection Agency proposes 

to amendis amending 40 CFR chapter I of the Code of Federal Regulations as follows: 

PART 85-- CONTROL OF AIR POLLUTION FROM MOBILE SOURCES 

1. The authority citation for part 85 continues to read as follows: 

Authority: 42 U.S.C. 7401-7671q.

Subpart F—[Amended] 

2. Section 85.525 is revised to read as follows: 

§ 85.525 Applicable standards. 

To qualify for an exemption from the tampering prohibition, vehicles/engines that have 

been converted to operate on a different fuel must meet emission standards and related 

requirements as follows: 

(a) The modified vehicle/engine must meet the requirements that applied for the OEM 

vehicle/engine, or the most stringent OEM vehicle/engine standards in any allowable 

grouping. Fleet average standards do not apply unless clean alternative fuel conversions 

are specifically listed as subject to the standards. 

(1) If the vehicle/engine was certified with a Family Emission Limit for NOx, 

NOx+HC, or particulate matter, as noted on the vehicle/engine emission control 

information label, the modified vehicle/engine may not exceed this Family Emission 

Limit. 

(2) Compliance with greenhouse gas emission standards is demonstrated as follows: 

(i)(i) Subject to the following exceptions and special provisions, compliance with 

light-duty vehicle greenhouse gas emission standards is demonstrated by 

complying with the N2O and CH4 standards and provisions set forth in 40 CFR 

86.1818–12(f)(1) and the in-use CO2 exhaust emission standard set forth in 40 

CFR 86.1818–12(d) as determined by the OEM for the subconfiguration that is

identical to the fuel conversion emission data vehicle (EDV). 

(A) If the OEM complied with the light-duty greenhouse gas standards using 

the fleet averaging option for nitrous oxide (N2O) and methane (CH4),, as 

allowed under 40 CFR 86.1818–12(f)(2), the calculations of the carbonrelated exhaust emissions require the input of grams/mile values for N2O and 

CH4. Compliance with N2O and CH4 exhaust emission standards may be 

optionally demonstrated by following the same procedures set forth in 40 CFR 

86.1818–12(f)(2), except that the carbon-related exhaust emission value 

determined for the fuel conversion EDV must comply with the in-use CO2

exhaust emission standard set forth in 40 CFR 86.1818–12(d) and determined 

by the OEM for the subconfiguration that is identical to the fuel conversion 

EDV., and you are not required to demonstrate compliance with the 

standalone CH4 and N2O standards. 
(B) If the OEM complied with alternate standards for N2O and/or CH4, as 

allowed under 40 CFR 86.1818–12(f)(3), you may demonstrate compliance 

with the same alternate standards.

(C) If the OEM complied with the nitrous oxide (N2O) and methane (CH4) 

standards and provisions set forth in 40 CFR 86.1818–12(f)(1) or 40 CFR 

86.1818–12(f)(3), and the fuel conversion CO2 measured value is lower than 

the in-use CO2 exhaust emission standard, you also have the option to 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.

(ii) Compliance with heavy-duty engine greenhouse gas emission standards is 

demonstrated by complying with the CO2, N2O, and CH4 standards (or FELs, as 

applicable) and provisions set forth in 40 CFR 1036.108 for the engine family that 

is represented by the fuel conversion emission data engine (EDE). If the fuel 

conversion CO2 measured value is lower than the CO2 standard (or FEL, as 

applicable), you have the option to convert the difference between the CO2

standard (or FEL, as applicable) and the fuel conversion CO2 measured value into 

GHG equivalents of CH4 and/or N2O, using 298 g/hp-hr CO2 to represent 1 g/hphr N2O and 25 g/hp-hr CO2 to represent 1 g/hp-hr 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 (or 

FEL, as applicable).

(3) Conversion systems for engines that would have qualified for chassis certification 

at the time of OEM certification may use those procedures, even if the OEM did not. 

Conversion manufacturers choosing this option must designate test groups using the 

appropriate criteria as described in this subpart and meet all vehicle chassis 

certification requirements set forth in 40 CFR part 86, subpart S. 

(b) [Reserved] 

Subpart P—[Amended] 

3. Section 85.1511 is revised to read as follows: 

§ 85.1511 Exemptions and exclusions. 

(a) Individuals, as well as certificate holders, shall be eligible for importing vehicles into 

the United States under the provisions of this section, unless otherwise specified. 

(b) Notwithstanding any other requirements of this subpart, a motor vehicle or motor 

vehicle engine entitled to a temporary exemption under this paragraph (b) may be 

conditionally admitted into the United States if prior written approval for such 

conditional admission is obtained from the Administrator. Conditional admission shall be 

under bond. A written request for approval from the Administrator shall contain the 

identification required in § 85.1504(a)(1) (except for § 85.1504(a)(1)(v)) and information 

that indicates that the importer is entitled to the exemption. Noncompliance with 
provisions of this section may result in the forfeiture of the total amount of the bond or 

exportation of the vehicle or engine. The following temporary exemptions are permitted 

by this paragraph (b): 

(1) Exemption for repairs or alterations. Vehicles and engines may qualify for a 

temporary exemption under the provisions of 40 CFR 1068.325(a). Such vehicles or 

engines may not be registered or licensed in the United States for use on public roads 

and highways. 

(2) Testing exemption. Vehicles and engines may qualify for a temporary exemption 

under the provisions of 40 CFR 1068.325(b). Test vehicles or engines may be 

operated on and registered for use on public roads or highways provided that the 

operation is an integral part of the test. 

(3) Precertification exemption. Prototype vehicles for use in applying to EPA for 

certification may be imported by independent commercial importers subject to 

applicable provisions of 40 CFR 85.1706 and the following requirements: 

(i) No more than one prototype vehicle for each engine family for which an 

independent commercial importer is seeking certification shall be imported by 

each independent commercial importer. 

(ii) Unless a certificate of conformity is issued for the prototype vehicle, the total 

amount of the bond shall be forfeited or the vehicle must be exported within 180 

days from the date of entry. 

(4) Display exemptions. Vehicles and engines may qualify for a temporary exemption 

under the provisions of 40 CFR 1068.325(c). Display vehicles or engines may not be 

registered or licensed for use or operated on public roads or highways in the United 

States, unless an applicable certificate of conformity has been received. 

(c) Notwithstanding any other requirements of this subpart, a motor vehicle or motor 

vehicle engine may be finally admitted into the United States under this paragraph (c) if 

prior written approval for such final admission is obtained from the Administrator. 

Conditional admission of these vehicles is not permitted for the purpose of obtaining 

written approval from the Administrator. A request for approval shall contain the 

identification information required in § 85.1504(a)(1) (except for § 85.1504(a)(1)(v)) and 

information that indicates that the importer is entitled to the exemption or exclusion. The 

following exemptions or exclusions are permitted by this paragraph (c): 

(1) National security exemption. Vehicles may be imported under the national 

security exemption found at 40 CFR 1068.315(a). Only persons who are 

manufacturers may import a vehicle under a national security exemption. 

(2) Hardship exemption. The Administrator may exempt on a case-by-case basis 

certain motor vehicles from Federal emission requirements to accommodate 

unforeseen cases of extreme hardship or extraordinary circumstances. Some examples 

are as follows: 

(i) Handicapped individuals who need a special vehicle unavailable in a certified 

configuration; 

(ii) Individuals who purchase a vehicle in a foreign country where resale is 

prohibited upon the departure of such an individual; 

(iii) Individuals emigrating from a foreign country to the U.S. in circumstances of 

severe hardship. 
(d) Foreign diplomatic and military personnel may import nonconforming vehicles 

without bond. At the time of admission, the importer shall submit to the Administrator 

the written report required in § 85.1504(a)(1) (except for information required by 

§ 85.1504(a)(1)(v)). Such vehicles may not be sold in the United States. 

(e) Racing vehicles may be imported by any person provided the vehicles meet one or 

more of the exclusion criteria specified in § 85.1703. Racing vehicles may not be 

registered or licensed for use on or operated on public roads and highways in the United 

States. 

(f) The following exclusions and exemptions apply based on date of original 

manufacture: 

(1) Notwithstanding any other requirements of this subpart, the following motor 

vehicles or motor vehicle engines are excluded from the requirements of the Act in 

accordance with section 216(3) of the Act and may be imported by any person:

(i) Gasoline-fueled light-duty vehicles and light-duty trucks originally 

manufactured prior to January 1, 1968. 

(ii) Diesel-fueled light-duty vehicles originally manufactured prior to January 1, 

1975. 

(iii) Diesel-fueled light-duty trucks originally manufactured prior to January 1, 

1976. 

(iv) Motorcycles originally manufactured prior to January 1, 1978. 

(v) Gasoline-fueled and diesel-fueled heavy-duty engines originally manufactured 

prior to January 1, 1970. 

(2) Notwithstanding any other requirements of this subpart, a motor vehicle or motor 

vehicle engine not subject to an exclusion under paragraph (f)(1) of this section but 

greater than twenty OP years old is entitled to an exemption from the requirements of 

the Act, provided that it is imported into the United States by a certificate holder. At 

the time of admission, the certificate holder shall submit to the Administrator the 

written report required in § 85.1504(a)(1) (except for information required by 

§ 85.1504(a)(1)(v)). 

(g) Applications for exemptions and exclusions provided for in paragraphs (b) and (c) of 

this section shall be mailed to the Designated Compliance Officer (see 40 CFR 1068.30). 

(h) Vehicles conditionally or finally admitted under this section must still comply with all 

applicable requirements, if any, of the Energy Tax Act of 1978, the Energy Policy and 

Conservation Act and any other Federal or state requirements. 

Subpart R—[Amended] 

4. Section 85.1701 is revised to read as follows: 

§ 85.1701 General applicability. 

(a) The provisions of this subpart regarding exemptions are applicable to new and in-use 

motor vehicles and motor vehicle engines, except as specified in this paragraph (a). 

(1) Beginning January 1, 2014 the exemption importation provisions of 40 CFR part 

1068, subpart C, apply for heavy-duty motor vehiclevehicles and engines, except that

the competition exemption of 40 CFR 1068.235 and the hardship exemption 

provisions of 40 CFR 1068.245, 1068.250, and 1068.255 do not apply for motor 

vehicle engines. 
(2) Prior to January 1, 2014, the provisions of §§85.1706, 85.1707, 85.1708, and 

85.1709 apply for heavy-duty motor vehicle engines. 

(b) The provisions of this subpart regarding exclusion are applicable after the effective 

date of these regulations. 

(c) References in this subpart to engine families and emission control systems shall be 

deemed to apply to durability groups and test groups as applicable for manufacturers 

certifying new light-duty vehicles, light-duty trucks, and Otto-cycle complete heavy-duty 

vehicles under the provisions of 40 CFR part 86, subpart S. 

(d) In a given model year, manufacturers of motor vehicles and motor vehicle engines 

may ask us to approve the use of administrative or compliance procedures specified in 40 

CFR part 1068 instead of the comparable procedures that apply for vehicles or engines 

certified under this part or 40 CFR part 85 or 86. 

Subpart T—[Amended]

5. Section 85.1901 is revised to read as follows: 

§ 85.1901 Applicability. 

Except as specified in this section, the requirements of this subpart shall be applicable to 

all 1972 and later model year vehicles and engines. The requirement to report emissionrelated defects affecting a given class or category of vehicles or engines shall remain 

applicable for five years from the end of the model year in which such vehicles or 

engines were manufactured. Manufacturers of heavy-duty motor vehicle engines may 

comply with the defect reporting requirements of 40 CFR 1068.501 instead of the 

requirements of this subpart. 

PART 86--CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY 

VEHICLES AND ENGINES 

6. The authority citation for part 86 continues to read as follows: 

Authority: 42 U.S.C. 7401-7671q. 

7. Section 86.1 is amended by adding paragraphs (b)(2)(xli) and (b)(2)(xlii) and 

removing and reserving paragraph (b)(4)(i)(A) to read as follows:

§ 86.1 Reference materials.

* * * * *

(b) * * *

(2) * * *

(xli) SAE J1711, Recommended Practice for Measuring the Exhaust Emissions and Fuel 

Economy of Hybrid-Electric Vehicles, Including Plug-In Hybrid Vehicles, June 2010, 

IBR approved for § 86.1811-04(n). 

(xlii) SAE J1634, Electric Vehicle Energy Consumption and Range Test Procedure, 

Cancelled October 2002, IBR approved for § 86.1811-04(n). 

* * * * *

(4) * * *

(i) * * *

(A) [Reserved] 
* * * * *

Subpart A – [Amended] 

7.8.Section 86.007-23010-18 is amended by adding paragraph (oparagraphs (j)(1)(ii)(E) 

and (q) to read as follows: 

§ 86.007-23 Required data.

* * * * *

(o) The provisions of this paragraph (o) apply for certification testing starting with the 

2014 model year and apply for HC, CO, NOx, PM, and CO2. 

(1) For heavy-duty engines tested over the transient engine test cycle, manufacturers must 

report these emissions separately for cold-start testing and hot-start testing. 

(2) For heavy-duty engines tested over the SET cycle, manufacturers must g/hp-hr 

emission results for each steady-state test mode for each pollutant except PM. Where we 

require you to measure SET emissions using a ramped modal cycle, compliance with the 

duty cycle emission standards is based on the ramped modal results and not the individual 

modal results. We may waive this requirement where you provide equivalent data from 

other testing. 

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

14,000 pounds GVWR.

* * * * *

(j) * * *

(1) * * *

(ii) * * *

(E) For hybrid engine families with projected U.S.-directed production volume of less 

than 5,000 engines, the manufacturers are only required to test one engine-hybrid 

combination per family. 

* * * * *

(q) Optional phase-in for hybrid vehicles. This paragraph (q) applies for model year 

2013 - 2015 engines when used with hybrid powertrain systems. It also applies for model 

year 2016 engines used with hybrid powertrain systems that were offered for sale prior to 

January 1, 2013, as specified in paragraph (q)(4) of this section. Manufacturers choosing 

to use the provisions of this paragraph (q) must submit an annual pre-compliance report 

to EPA for model years 2013 and later, as specified in paragraph (q)(5) of this section. 

Note that all hybrid powertrain systems must be fully compliant with the OBD 

requirements of this section no later than model year 2017.

(1) If an engine-hybrid system has been certified by the California Air Resources Board 

with respect to its OBD requirements and it effectively meets the full OBD requirements 

of this section, all equivalent systems must meet those same requirements and may not be 

certified under this paragraph (q). For purposes of this paragraph (q)(1), an enginehybrid system is considered to be equivalent to the certified system if it uses the same 

basic design (e.g. displacement) for the engine and primary hybrid components (see 

paragraph (q)(4) of this section). Equivalent systems may have minor hardware or 

calibration differences.
(2) As of 2013, if an engine-hybrid system has not been certified to meet the full OBD 

requirements of this section, it must comply with the following requirements: 

(i) The engine in its installed configuration must meet the EMD and EMD+ 

requirements in 13 CCR §1971.1(d)(7.1.4) of the California Code of Regulations. 

For purposes of this paragraph (q), a given EMD requirement is deemed to be met 

if the engine’s OBD system addresses the same function. This allowance does not 

apply for OBD monitors or diagnostics that have been modified under paragraph 

(q)(2)(ii) of this section.

(ii) The engine-hybrid system must maintain existing OBD capability for engines 

where the same or equivalent engine has been OBD certified. An equivalent 

engine is one produced by the same engine manufacturer with the same 

fundamental design, but that may have hardware or calibration differences that do 

not impact OBD functionality, such as slightly different displacement, rated 

power, or fuel system. (Note that engines with the same fundamental design will 

be presumed to be equivalent unless the manufacturer demonstrates that the 

differences effectively preclude applying equivalent OBD systems.) Though the 

OBD capability must be maintained, it does not have to meet detection thresholds 

(as described in Tables 1 and 2 of this section) and in-use performance frequency 

requirements (as described in paragraph (d) of this section). A manufacturer may 

modify detection thresholds to prevent false detection, and must indicate all 

deviations from the originally certified package with engineering justification in 

the certification documentation. 

(iii) This paragraph (q)(2)(iii) applies for derivatives of hybrid powertrain system 

designs that were offered for sale prior to January 1, 2013. Until these systems 

achieve full OBD certification, they must at a minimum maintain all faultdetection and diagnostic capability included on similar systems offered for sale 

prior to 2013. Manufacturers choosing to use the provisions of this paragraph 

(q)(2) must keep copies of the service manuals (and similar documents) for these 

previous model years to show the technical description of the system’s fault 

detection and diagnostic capabilities.

(iv) You must submit an annual pre-compliance report to EPA for model years 

2013 and later, as specified in paragraph (q)(5) of this section.

(3) Engine-hybrid systems may be certified to the requirements of paragraph (q)(2) of 

this section by the engine manufacturer, the hybrid system manufacturer, or the vehicle 

manufacturer. If engine manufacturers certify the engine hybrid system, they must 

provide detailed installation instructions. Where the engine manufacturer does not 

specifically certify its engines for use in hybrid vehicles under this paragraph (q), the 

hybrid system manufacturer and vehicle manufacturer must install the engine to conform 

to the requirements of this section (i.e., full OBD) or recertify under paragraph (q)(2) of 

this section.

(4) The provisions of this paragraph (q) apply for model year 2016 engines where you 

demonstrate that the hybrid powertrain system used is a derivative of a design that was 

offered for sale prior to January 1, 2013. In this case, you may ask us to consider the 

original system and the later system to be the same model for purposes of this paragraph 

(q), unless the systems are fundamentally different. In determining whether such systems 
are derivative or fundamentally different, we will consider factors such as the similarity 

of the following:

(i) Transmissions.

(ii) Hybrid machines (where “hybrid machine” means any system that is the part 

of a hybrid vehicle system that captures energy from and returns energy to the 

powertrain).

(iii) Hybrid architecture (such as parallel or series).

(iv) Motor/generator size, controller/CPU (memory or inputs/outputs), control 

algorithm, and batteries. This paragraph (q)(4)(iv) applies only if all of these are 

modified simultaneously.

(5) Manufacturers choosing to use the provisions of this paragraph (q) must submit an 

annual pre-compliance report to EPA for model years 2013 and later. Engine 

manufacturers must submit this report with their engine certification information. Hybrid 

manufacturers that are not certifying the engine-hybrid system must submit their report 

by June 1 of the model year, or at the time of certification if they choose to certify. 

Include the following in the report:

(i) A description of the manufacturer’s product plans and of the engine-hybrid 

systems being certified. 

(ii) A description of activities undertaken and progress made by the manufacturer 

towards achieving full OBD certification, including monitoring, diagnostics, and 

standardization.

 (iii) For model year 2016 engines, a description of your basis for applying the

provision of this paragraph (q) to the engines.

9. A new § 86.012-2 is added to subpart A to read as follows:

§ 86.012-2 Definitions. 

The definitions of §86.010–2 continue to apply to model year 2010 and later model year 

vehicles. The definitions listed in this section apply beginning with model year 2012.

Urban bus means a passenger-carrying vehicle with a load capacity of fifteen or more 

passengers and intended primarily for intracity operation, i.e., within the confines of a 

city or greater metropolitan area. Urban bus operation is characterized by short rides and 

frequent stops. To facilitate this type of operation, more than one set of quick-operating 

entrance and exit doors would normally be installed. Since fares are usually paid in cash 

or tokens, rather than purchased in advance in the form of tickets, urban buses would 

normally have equipment installed for collection of fares. Urban buses are also typically 

characterized by the absence of equipment and facilities for long distance travel, e.g., rest 

rooms, large luggage compartments, and facilities for stowing carry-on luggage. 

8.10. A new § 86.016-1 is added to subpart A to read as follows: 

§ 86.016-1 General applicability. 

(a) Applicability. The provisions of this subpart generally apply to 2005 and later model 

year new Otto-cycle heavy-duty engines used in incomplete vehicles and vehicles above 

14,000 pounds GVWR and 2005 and later model year new diesel-cycle heavy-duty 

engines. In cases where a provision applies only to a certain vehicle group based on its 

model year, vehicle class, motor fuel, engine type, or other distinguishing characteristics, 
the limited applicability is cited in the appropriate section or paragraph. The provisions of 

this subpart continue to generally apply to 2000 and earlier model year new Otto-cycle 

and diesel-cycle light-duty vehicles, 2000 and earlier model year new Otto-cycle and 

diesel-cycle light-duty trucks, and 2004 and earlier model year new Otto-cycle complete 

heavy-duty vehicles at or below 14,000 pounds GVWR. Provisions generally applicable 

to 2001 and later model year new Otto-cycle and diesel-cycle light-duty vehicles, 2001 

and later model year new Otto-cycle and diesel-cycle light-duty trucks, and 2005 and 

later model year Otto-cycle complete heavy-duty vehicles at or below 14,000 pounds 

GVWR are located in subpart S of this part. 

(b) Optional applicability. A manufacturer may request to certify any incomplete Ottocycle heavy-duty vehicle of 14,000 pounds Gross Vehicle Weight Rating or less in 

accordance with the provisions for Otto-cycle complete heavy-duty vehicles located in 

subpart S of this part. Heavy-duty engine or heavy-duty vehicle provisions of this subpart 

A do not apply to such a vehicle. 

(c) Otto-cycle heavy-duty engines and vehicles. The following requirements apply to 

Otto-cycle heavy-duty engines and vehicles: 

(1) Exhaust emission standards according to the provisions of § 86.008-10 or 

§ 86.1816, as applicable. 

(2) On-board diagnostics requirements according to the provisions of § 86.007–17 or

§ 86.1806, as applicable. 

(3) Evaporative emission standards as follows: 

(i) Evaporative emission standards for complete vehicles according to the

provisions of §§ 86.1810 and 86.1816. 

(ii) For 2013 and earlier model years, evaporative emission standards for

incomplete vehicles according to the provisions of § 86.008-10, or §§ 86.1810 

and 86.1816, as applicable. 

(iii) For 2014 and later model years, evaporative emission standards for 

incomplete vehicles according to the provisions of §§ 86.1810 and 86.1816, or 40 

CFR part 1037, as applicable. 

(4) Refueling emission requirements for Otto-cycle complete vehicles according to 

the provisions of §§ 86.1810 and 86.1816. 

 (d) Non-petroleum fueled vehicles. The standards and requirements of this part apply to 

model year 2016 and later non-petroleum fueled motor vehicles as follows: 

(1) The standards and requirements of this part apply as specified for vehicles fueled 

with methanol, natural gas, and LPG. 

(2) The standards and requirements of subpart S of this part apply as specified for 

light-duty vehicles and light-duty trucks. 

(3) The standards and requirements of this part applicable to methanol-fueled heavyduty vehicles and engines (including flexible fuel vehicles and engines) apply to 

heavy-duty vehicles and engines fueled with any oxygenated fuel (including flexible 

fuel vehicles and engines). Most significantly, this means that the hydrocarbon 

standards apply as NMHCE and the vehicles and engines must be tested using the 

applicable oxygenated fuel according to the test procedures in 40 CFR part 1065 

applicable for oxygenated fuels. For purposes of this paragraph (d), oxygenated fuel 

means any fuel containing at least 50 volume percent oxygenated compounds. For 

example, a fuel mixture of 85 gallons of ethanol and 15 gallons of gasoline is an 
oxygenated fuel, while a fuel mixture of 15 gallons of ethanol and 85 gallons of

gasoline is not an oxygenated fuel. 

(4) The standards and requirements of subpart S of this part applicable to heavy-duty 

vehicles under 14,000 pounds GVWR apply to all heavy-duty vehicles powered 

solely by electricity, including plug-in electric vehicles and solar-powered vehicles. 

Use good engineering judgment to apply these requirements to these vehicles, 

including applying these provisions to vehicles over 14,000 pounds GVWR. Electric 

heavy-duty vehicles may not generate NOx or PM emission credits. Heavy-duty 

vehicles powered solely by electricity are deemed to have zero emissions of regulated 

pollutants. 

(5) The standards and requirements of this part applicable to diesel-fueled heavy-duty 

vehicles and engines apply to all other heavy-duty vehicles and engines not otherwise 

addressed in this paragraph (d). 

(6) See 40 CFR parts 1036 and 1037 for requirements related to greenhouse gas 

emissions. 

(7) Manufacturers may voluntarily certify to the standards of paragraphs (d)(3) 

through (5) of this section before model year 2016. Note that other provisions in this 

part require compliance with the standards described in paragraphs (d)(1) and (2) of 

this section for model years before 2016. 

(e) Small volume manufacturers. Special certification procedures are available for any 

manufacturer whose projected combined U.S. sales of light-duty vehicles, light-duty 

trucks, heavy-duty vehicles, and heavy-duty engines in its product line (including all 

vehicles and 

engines imported under the provisions of 40 CFR 85.1505 and 85.1509 of this chapter) 

are fewer than 10,000 units for the model year in which the manufacturer seeks 

certification. To certify its product line under these optional procedures, the smallvolume manufacturer must first obtain the Administrator's approval. The manufacturer 

must meet the eligibility criteria specified in § 86.098-14(b) before the Administrator's 

approval will be granted. The small-volume manufacturer's certification procedures are 

described in § 86.098-14. 

(f) Optional procedures for determining exhaust opacity. (1) The provisions of subpart I 

of this part apply to tests which are performed by the Administrator, and optionally, 

by the manufacturer. 

(2) Measurement procedures, other than those described in subpart I of this part, may 

be used by the manufacturer provided the manufacturer satisfies the requirements of 

§ 86.007-23(f). 

(3) When a manufacturer chooses to use an alternative measurement procedure, it has 

the responsibility to determine whether the results obtained by the procedure will 

correlate with the results which would be obtained from the measurement procedure 

in subpart I of this part. Consequently, the Administrator will not routinely approve or 

disapprove any alternative opacity measurement procedure or any associated 

correlation data which the manufacturer elects to use to satisfy the data requirements 

for subpart I of this part. 

(4) If a confirmatory test is performed and the results indicate there is a systematic 

problem suggesting that the data generated under an optional alternative measurement 

procedure do not adequately correlate with data obtained in accordance with the 
procedures described in subpart I of this part, EPA may require that all certificates of 

conformity not already issued be based on data obtained from procedures described in 

subpart I of this part. 

 

11. Section 86.090-2 is amended by revising the definition of “primary intended service 

class” to read as follows:

§ 86.090-2 Definitions.

* * * * *

Primary intended service class has the meaning given in 40 CFR 1036.140.

* * * * * 

Subpart B – [Amended] 

9.12. Section 86.144-94 is amended by adding paragraphs (b)(11) and (c)(10) to read as 

follows: 

§ 86.144-94 Calculations; exhaust emissions. 

* * * * * 

(b) * * * 

(11) Nitrous Oxide Mass: Vmix x DensityN2O x (N2Oconc/1,000,000) 

(c) * * * 

(10)(i) N2Omass=Nitrous oxide emissions, in grams per test phase. 

(ii) DensityN2O=Density of nitrous oxide is 51.81 g/ft3

 (1.83 kg/m3), at 68 °F (20 °C) and 

760 mm Hg (101.3kPa) pressure. 

(iii)(A) N2Oconc=Nitrous oxide concentration of the dilute exhaust sample corrected for

background, in ppm. 

(B) N2Oconc=N2Oe-N2Od(1-(1/DF)). 

Where: 

N2Oe=Nitrous oxide concentration of the dilute exhaust sample as measured, in ppm. 

N2Od= Nitrous oxide concentration of the dilution air as measured, in ppm. 

* * * * * 

Subpart F – [Amended] 

10.13. Section 86.544-90 is amended by adding paragraphs (b)(8) and (c)(8) to read as 

follows: 

§ 86.544-90 Calculations; exhaust emissions. 

* * * * * 

(b) * * * 

(8) Nitrous Oxide Mass: Vmix x DensityN2O x (N2Oconc/1,000,000) 

(c) * * * 

(8)(i) N2Omass=Nitrous oxide emissions, in grams per test phase. 

(ii) DensityN2O=Density of nitrous oxide is 51.81 g/ft3 (1.83 kg/m3), at 68 °F (20 °C) and 

760 mm Hg (101.3kPa) pressure. 

(iii)(A) N2Oconc=Nitrous oxide concentration of the dilute exhaust sample corrected for

background, in ppm. 

(B) N2Oconc=N2Oe-N2Od(1-(1/DF)). 
Where: 

N2Oe=Nitrous oxide concentration of the dilute exhaust sample as measured, in ppm. 

N2Od= Nitrous oxide concentration of the dilution air as measured, in ppm. 

* * * * * 

Subpart N – [Amended] 

11.14. Section 86.1305-2010 is amended by revising paragraph (b) to read as follows: 

§ 86.1305-2010 Introduction; structure of subpart. 

* * * * * 

(b) Use the applicable equipment and procedures for spark-ignition or compressionignition engines in 40 CFR part 1065 to determine whether engines meet the duty-cycle 

emission standards in subpart A of this part. Measure the emissions of all regulated 

pollutants as specified in 40 CFR part 1065. Use the duty cycles and procedures specified 

in §§86.1333–2010, 86.1360–2007, and 86.1362–2010. Adjust emission results from 

engines using aftertreatment technology with infrequent regeneration events as described 

in §86.004–28. 

* * * * * 

Subpart S – [Amended]

§ 86.1806-01—[Amended]

15. Section 86.1362-20101806-01 is amended by addingremoving and reserving

paragraph (fb)(8)(ii).

§ 86.1806-05—[Amended]

16. Section 86.1806-05 is amended by removing and reserving paragraph (b)(8)(ii).

12.17. Section 86.1811-04 is amended by revising paragraph (n) to read as follows: 

§ 86.1362-2010 Steady-state testing with a ramped-modal cycle1811-04 Emission 

standards for light-duty vehicles, light-duty trucks and medium-duty passenger 

vehicles. 

* * * * * 

(f) Starting in the 2014 model year, use continuous sampling to determine separate 

emission rates at each test mode during the test run for each pollutant except PM, as 

described in 40 CFR 1036.501. n) Hybrid electric vehicle (HEV) and Zero Emission 

Vehicle (ZEV) requirements. For FTP and SFTP exhaust emissions, manufacturers must 

measure emissions from all HEVs and ZEVs according to the procedures specified in 

SAE J1711 and SAE J1634, respectively (incorporated by reference in § 86.1).

Subpart S – [Amended]

* * * * *

13.18. Section 86.1818-12 is amended by revising paragraph (f) to read as follows: 

§ 86.1818-12 Greenhouse gas emission standards for light-duty vehicles, light-duty 

trucks, and medium-duty passenger vehicles. 
* * * * *

* * * * *

(f) Nitrous oxide (N2O) and methane (CH4) exhaust emission standards for passenger 

automobiles and light trucks. Each manufacturer's fleet of combined passenger 

automobile and light trucks must comply with N2O and CH4 standards using either the 

provisions of paragraph (f)(1), (f)(2), or (f)(3) of this section. TheExcept with prior EPA 

approval, a manufacturer may not use the provisions of both paragraphs (f)(1) and (f)(2) 

of this section in a model year. For example, a manufacturer may not use the provisions 

of paragraph (f)(1) of this section for their passenger automobile fleet and the provisions 

of paragraph (f)(2) for their light truck fleet in the same model year. The manufacturer 

may use the provisions of both paragraphs (f)(1) and (f)(3) of this section in a model 

year. For example, a manufacturer may meet the N2O standard in paragraph (f)(1)(i) of 

this section and an alternative CH4 standard determined under paragraph (f)(3) of this 

section. Use of the provisions in paragraph (f)(3) is limited to the 2012 through 2016 

model years. 

(1) Standards applicable to each test group. (i) Exhaust emissions of nitrous oxide (N2O) 

shall not exceed 0.010 grams per mile at full useful life, as measured according to the 

Federal Test Procedure (FTP) described in subpart B of this part. Manufacturers may 

optionally determine an alternative N2O standard under paragraph (f)(3) of this section. 

(ii) Exhaust emissions of methane (CH4) shall not exceed 0.030 grams per mile at full 

useful life, as measured according to the Federal Test Procedure (FTP) described in 

subpart B of this part. Manufacturers may optionally determine an alternative CH4

standard under paragraph (f)(3) of this section. 

(2) Include N2O and CH4 in fleet averaging program. Manufacturers may elect to not 

meet the emission standards in paragraph (f)(1) of this section. Manufacturers making 

this election shall include N2O and CH4 emissions in the determination of their fleet 

average carbon-related exhaust emissions, as calculated in subpart F of part 600 of this 

chapter. Manufacturers using this option must include both N2O and CH4 full useful life 

values in the fleet average calculations for passenger automobiles and light trucks. Use of 

this option will account for N2O and CH4 emissions within the carbon-related exhaust 

emission value determined for each model type according to the provisions of part 600 of 

this chapter. This option requires the determination of full useful life emission values for 

both the Federal Test Procedure and the Highway Fuel Economy Test. Manufacturers 

selecting this option are not required to demonstrate compliance with the standards in 

paragraph (f)(1) of this section. 

(3) Optional use of alternative N2O and/or CH4 standards. Manufacturers may select an 

alternative standard applicable to a test group, for either N2O, CH4, or both. For example, 

a manufacturer may choose to meet the N2O standard in paragraph (f)(1)(i) of this section 

and an alternative CH4 standard in lieu of the standard in paragraph (f)(1)(ii) of this 

section. The alternative standard for each pollutant must be greater than the applicable 

exhaust emission standard specified in paragraph (f)(1) of this section. Alternative N2O 

and CH4 standards apply to emissions measured according to the Federal Test Procedure 

(FTP) described in Subpart B of this part for the full useful life, and become the 

applicable certification and in-use emission standard(s) for the test group. Manufacturers 
using an alternative standard for N2O and/or CH4 must calculate emission debits 

according to the provisions of paragraph (f)(4) of this section for each test 

group/alternative standard combination. Debits must be included in the calculation of 

total credits or debits generated in a model year as required under § 86.1865-12(k)(5). 

For flexible fuel vehicles (or other vehicles certified for multiple fuels) you must meet 

these alternative standards when tested on any applicable test fuel type. 

(4) CO2-equivalent debits. CO2-equivalent debits for test groups using an alternative N2O

andN2Oand/or CH4standardCH4 standard as determined under paragraph (f)(3) of this 

section shall be calculated according to the following equation and rounded to the nearest 

megagram: 

Debits = [GWP x (Production) x (AltStd – Std) x VLM] / 1,000,000 

Where: 

Debits = N2O or CH4 CO2-equivalent debits for a test group using an alternative N2O or 

CH4 standard; 

GWP = 25 if calculating CH4 debits and 298 if calculating N2O debits; 

Production = The number of vehicles of that test group domestically produced plus those 

imported as defined in §600.511–80 of this chapter; 

AltStd = The alternative standard (N2O or CH4) selected by the manufacturer under 

paragraph (f)(3) of this section; 

Std = The exhaust emission standard for N2O or CH4 specified in paragraph (f)(1) of this 

section; and 

VLM = 195,264 for passenger automobiles and 225,865 for light trucks. 

19. Section 86.1823-08 is amended by revising paragraphs (m)(1)(i), (m)(2), (m)(3), and 

(m)(4) to read as follows:

§ 86.1823-08 Durability demonstration procedures for exhaust emissions.

* * * * *

(m) * * *

(1) * * *

(i) Unless otherwise specified under paragraph (m)(1)(ii) of this section, manufacturers 

may use a multiplicative CO2 deterioration factor of one or an additive deterioration 

factor of zero to determine full useful life emissions for the FTP and HFET tests.

* * * * *

(2) N2O and CH4. (i) For manufacturers complying with the FTP emission standards for

N2O and CH4 specified in §86.1818–12(f)(1) or determined under §86.1818–12 (f)(3), 

FTP-based deterioration factors for N2O and CH4 shall be determined according to the 

provisions of paragraphs (a) through (l) of this section.

(ii) For manufacturers complying with the fleet averaging option for N2O and CH4 as 

allowed under §86.1818–12(f)(2), deterioration factors based on FTP testing shall be

determined and may be used to determine full useful life emissions for the FTP and 

HFET tests. The manufacturer may at its option determine separate deterioration factors 

for the FTP and HFET test cycles, in which case each FTP test performed on the 

durability data vehicle selected under §86.1822–01 of this part must also be accompanied 

by an HFET test.
(iii) For the 2012 through 2014 model years only, manufacturers may use alternative 

deterioration factors. For N2O, the alternative deterioration factor to be used to adjust 

FTP and HFET emissions is the deterioration factor determined for NOx emissions 

according to the provisions of this section. For CH4, the alternative deterioration factor to 

be used to adjust FTP and HFET emissions is the deterioration factor determined for 

NMOG or NMHC emissions according to the provisions of this section.

(3) Other carbon-related exhaust emissions. FTP-based deterioration factors shall be 

determined for carbon-related exhaust emissions (CREE), hydrocarbons, and CO 

according to the provisions of paragraphs (a) through (l) of this section. The FTP-based 

deterioration factor shall be used to determine full useful life emissions for both the FTP 

(city) and HFET (highway) test cycles. The manufacturer may at its option determine 

separate deterioration factors for the FTP and HFET test cycles, in which case each FTP 

test performed on the durability data vehicle selected under §86.1822 of this part must 

also be accompanied by an HFET test. In lieu of determining emission-specific 

deterioration factors for the specific hydrocarbons of CH3OH (methanol), HCHO 

(formaldehyde), C2H5OH (ethanol), and C2H4O (acetaldehyde) as may be required for 

some alternative fuel vehicles, manufacturers may use the additive or multiplicative 

deterioration factor determined for (or derived from, using good engineering judgment) 

NMOG or NMHC emissions according to the provisions of this section.

(4) Air Conditioning leakage and efficiency or other emission credit requirements to 

comply with exhaust CO2 standards. Manufactures will attest to the durability of 

components and systems used to meet the CO2 standards. Manufacturers may submit 

engineering data to provide durability demonstration. Deterioration factors do not apply 

to emission-related components and systems used to generate air conditioning leakage 

and/or efficiency credits. 

20. Section 86.1844-01 is amended by revising paragraph (d)(15) to read as follows:

§ 86.1844-01 Information requirements: Application for certification and submittal 

of information upon request.

* * * * *

(d) * * *

(15)(i) For HEVs and EVs, describe the recharging procedures and methods for 

determining battery performance, such as state of charge and charging capacity.

(ii) For vehicles with fuel-fired heaters, include the information specified in this 

paragraph (d)(15)(ii). Describe the control system logic of the fuel-fired heater, 

including an evaluation of the conditions under which it can be operated and an

evaluation of the possible operational modes and conditions under which evaporative 

emissions can exist. Use good engineering judgment to establish an estimated 

exhaust emission rate from the fuel-fired heater in grams per mile. Describe the 

testing used to establish the exhaust emission rate.

* * * * *

14.21. Section 86.1863-07 is revised to read as follows: 

§ 86.1863-07 Chassis certification for diesel vehicles. 

(a) A manufacturer may optionally certify heavy-duty diesel vehicles 14,000 pounds 

GVWR or less to the standards specified in § 86.1816. Such vehicles must meet all the 
requirements of this subpart S that are applicable to Otto-cycle vehicles, except for 

evaporative, refueling, and OBD requirements where the diesel-specific OBD 

requirements would apply. 

(b) For OBD, diesel vehicles optionally certified under this section are subject to the 

OBD requirements of § 86.1806. 

(c) Diesel vehicles certified under this section may be tested using the test fuels, sampling 

systems, or analytical systems specified for diesel engines in subpart N of this part or in 

40 CFR part 1065. 

(d) Diesel vehicles optionally certified under this section to the standards of this subpart 

may not be included in any averaging, banking, or trading program for criteria emissions 

under this part. 

(e) The provisions of § 86.004–40 apply to the engines in vehicles certified under this 

section. 

(f) Diesel vehicles may be certified under this section to the standards applicable to 

model year 2008 in earlier model years. 

(g) Diesel vehicles optionally certified under this section in model years 2007, 2008, or 

2009 shall be included in phase-in calculations specified in § 86.007–11(g). 

(h) Diesel vehicles subject to the standards of 40 CFR 1037.104 are subject to the 

provisions of this subpart as specified in 40 CFR 1037.104.(.

(i) Non-petroleum fueled complete vehicles subject to the standards and requirements of 

this part under §86.016-01(d)(5) are subject to the provisions of this section applicable to 

diesel-fueled heavy-duty vehicles. 

15.22. Section 86.1865-12 is amended by adding paragraphs (k)(5)(iv), and by revising 

paragraphs (k)(5), (l)(1)(i)(F), and (l)(2)(i) to read as follows: 

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

* * * * * 

(k) * * * 

(5) Total credits or debits generated in a model year, maintained and reported separately

for passenger automobiles and light trucks, shall be the sum of the credits or debits 

calculated in paragraph (k)(4) of this section and any of the following credits or debits, if 

applicable:

(i) Air conditioning leakage credits earned according to the provisions of §86.1866–

12(b);

(ii) Air conditioning efficiency credits earned according to the provisions of §86.1866–

12(c);

(iii) Off-cycle technology credits earned according to the provisions of §86.1866–12(d);

(5) * * * 

(iv) N2O and/or CH4 CO2-equivalent debits accumulated according to the provisions of § 

86.1818-12(f)(4). 

* * * * * 
(l) * * * 

(1) * * * 

(i) * * * 

(F) Carbon-related exhaust emission standard, N2O emission standard, and CH4 emission 

standard to which the passenger car or light truck is certified. 

* * * * * 

(2) * * * 

(i) Each manufacturer must submit an annual report. The annual report must contain for 

each applicable CO2 standard, the calculated fleet average CO2 value, all values required 

to calculate the CO2 emissions value, the number of credits generated or debits incurred, 

all the values required to calculate the credits or debits, and the resulting balance of 

credits or debits. For each applicable alternative N2O and/or CH4 standard selected under 

the provisions of § 86.1818-12(f)(3), the report must contain the N2O and/or CH4 CO2-

equivalent debits calculated according to § 86.1818-12(f)(4) for each test group and all 

values required to calculate the number of debits incurred. 

* * * * * 

PART 600— FUEL ECONOMY AND GREENHOUSE GAS EXHAUST 

EMISSIONS OF MOTOR VEHICLES 

23. The authority citation for part 600 continues to read as follows:

Authority: 49 U.S.C. 32901—23919q, Pub. L. 109–58.

Subpart A—[Amended]

24. Section 600.011 is amended by revising paragraph (c)(3) to read as follows:

§ 600.011 Incorporation by reference.

* * * * *

(c) * * *

(3) SAE J1711, Recommended Practice for Measuring the Exhaust Emissions and Fuel 

Economy of Hybrid-Electric Vehicles, Including Plug-In Hybrid Vehicles, June 2010, 

IBR approved for §§ 600.114-12(c) and (f), 600.116–12(b), and 600.311-12(d), (j), and 

(k).

* * * * *

Subpart B—[Amended]

25. Section 600.114-12 is amended by revising paragraphs (c), (e)(2)(ii), and (f) to read 

as follows:

§ 600.114-12 Vehicle-specific 5-cycle fuel economy and carbon-related exhaust 

emission calculations.

* * * * *

(c) Fuel economy calculations for hybrid electric vehicles. Test hybrid electric vehicles 

as described in SAE J1711 (incorporated by reference in § 600.011). For FTP testing, this 

generally involves emission sampling over four phases (bags) of the UDDS (cold-start, 
transient, warm-start, transient); however, these four phases may be combined into two 

phases (phases 1 + 2 and phases 3 + 4). Calculations for these sampling methods follow:

* * * * *

(e) * * *

(2) * * *

(ii) Determine the 5-cycle highway carbon-related exhaust emissions according to the 

following formula: 

(Start CREE RunningCREE) HighwayCREE

0.905

+

=

Where: 

(( ) )

60

.0 005515 A .1 13637 StartCREE StartCREE 33.0× + × 75 = ×

( ) 75 75 CREE 75 Start CREE = 3.6 × Bag 1CREE − Bag 3

[( ) ( )]

[ .0 377 .0 133 ( ) ( ) ( ) .0 00540 A .0 1357 US06 CREE ]

Running CREE .1 007 79.0 US06 Highway CREE 0.21 HFET CREE

× × × + ×

= × × + × +

* * * * *

(f) CO2 and carbon-related exhaust emissions calculations for hybrid electric vehicles.

Test hybrid electric vehicles as described in SAE J1711 (incorporated by reference in 

§ 600.011). For FTP testing, this generally involves emission sampling over four phases 

(bags) of the UDDS (cold-start, transient, warm-start, transient); however, these four 

phases may be combined into two phases (phases 1 + 2 and phases 3 + 4). Calculations 

for these sampling methods follow:

* * * * *

26. Section 600.115-11 is amended by revising the introductory text to read as follows:

§ 600.115-11 Criteria for determining the fuel economy label calculation method.

This section provides the criteria to determine if the derived 5-cycle method for 

determining fuel economy label values, as specified in § 600.210–08(a)(2) or (b)(2) or § 

600.210–12(a)(2) or (b)(2), as applicable, may be used to determine label values. 

Separate criteria apply to city and highway fuel economy for each test group. The 

provisions of this section are optional. If this option is not chosen, or if the criteria 

provided in this section are not met, fuel economy label values must be determined 

according to the vehicle-specific 5-cycle method specified in § 600.210–08(a)(1) or 

(b)(1) or § 600.210–12(a)(1) or (b)(1), as applicable. However, dedicated alternative-fuel 

vehicles, dual fuel vehicles when operating on the alternative fuel, plug-in hybrid electric 

vehicles while operating in charge-depleting mode, MDPVs, and vehicles imported by 

Independent Commercial Importers may use the derived 5-cycle method for determining 

fuel economy label values whether or not the criteria provided in this section are met. 

Manufacturers may alternatively account for this effect by multiplying 2-cycle fuel 

economy values by 0.7 and dividing 2-cycle CO2 emission values by 0.7.

* * * * *

27. Section 600.116-12 is amended by adding paragraph (a)(6) and revising the equation 
for UFi

 in paragraph (b)(4) to read as follows:

§ 600.116-12 Special procedures related to electric vehicles and plug-in hybrid 

electric vehicles.

(a) * * *

(6) All label values related to fuel economy, energy consumption, and range must be 

based on 5-cycle testing or on values adjusted to be equivalent to 5-cycle results.

(b) * * *

(4) * * *

1

1 1

1 exp

j

k n

i

i j i

j i

d

UF C UF

ND −

= =

       

= −    − ×      −

           

∑ ∑

* * * * *

Subpart C—[Amended]

28. Section 600.210-12 is amended by revising paragraph (d)(3)(ii) to read as follows:

§ 600.210-12 Calculation of fuel economy and CO2 emission values for labeling.

* * * * *

(d) * * *

(3) * * *

(ii) Multiply 2-cycle fuel economy values by 0.7 and divide 2-cycle CO2 emission values 

by 0.7. 

* * * * *

Subpart D—[Amended]

29. Section 600.302-12 is amended by revising paragraph (e)(4) to read as follows:

§ 600.302-12 Fuel economy label—general provisions.

(e) * * *

(4) Insert a slider bar in the right portion of the field to characterize the vehicle’s level of 

emission control for ozone-related air pollutants relative to that of all vehicles. Position a 

box with a downward-pointing wedge above the slider bar positioned to show where that 

vehicle's emission rating falls relative to the total range. Include the vehicle’s emission 

rating (as described in § 600.311) inside the box. Include the number 1 in the border at 

the left end of the slider bar; include the number 10 in the border at the right end of the 

slider bar and add the term “Best” below the slider bar, directly under the number. EPA 

will periodically calculate and publish updated range values as described in § 600.311. 

Add color to the slider bar such that it is blue at the left end of the range, white at the 

right end of the range, and shaded continuously across the range.

* * * * *

PART 1033— CONTROL OF EMISSIONS FROM LOCOMOTIVES

30. The authority citation for part 1033 continues to read as follows: 

Authority: 42 U.S.C. 7401-7671q.

Subpart G—[Amended]
31. Section 1033.625 is amended by revising paragraph (a)(2) to read as follows:

§ 1033.625 Special certification provisions for non-locomotive-specific engines.

* * * * *

(a) * * * 

(2) The engines were certified to PM, NOx, and hydrocarbon standards that are 

numerically lower than the applicable locomotive standards of this part.

* * * * *

16.32. A new part 1036 is added to subchapter U to read as follows: 

PART 1036--CONTROL OF EMISSIONS FROM NEW AND IN-USE HEAVYDUTY HIGHWAY ENGINES 

Subpart A—Overview and Applicability 

Sec. 

1036.1 Does this part apply for my engines? 

1036.2 Who is responsible for compliance? 

1036.5 Which engines are excluded from this part’s requirements? 

1036.10 How is this part organized? 

1036.15 Do any other regulation parts apply to me? 

1036.30 Submission of information. 

Subpart B—Emission Standards and Related Requirements 

1036.100 Overview of exhaust emission standards. 

1036.108 Greenhouse gas emission standards. 

1036.115 Other requirements. 

1036.130 Installation instructions for vehicle manufacturers. 

1036.135 Labeling. 

1036.140 Primary intended service class. 

1036.150 Interim provisions. 

Subpart C—Certifying Engine Families 

1036.205 What must I include in my application? 

1036.210 May I get Preliminary approval before I complete my application?certification.

1036.225 Amending my application for certification. 

1036.230 Selecting engine families. 

1036.235 Testing requirements for certification. 

1036.241 Demonstrating compliance with greenhouse gas pollutant standards. 

1036.250 Reporting and recordkeeping for certification. 

1036.255 What decisions may EPA make regarding my certificate of conformity? 

Subpart D—[Reserved] 
Subpart E—In-use Testing 

1036.401 In-use testing. 

Subpart F—Test Procedures 

1036.501 How do I run a valid emission test? 

1036.525 Hybrid engines. 

1036.530 Calculating greenhouse gas emission rates. 

Subpart G—Special Compliance Provisions 

1036.601 What compliance provisions apply to these engines? 

1036.610 Innovative technology credits and adjustments for reducing greenhouse gas 

emissions. 

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

1036.620 Alternate CO2 standards based on model year 2011 compression ignition 

engines. 

Subpart H—Averaging, Banking, and Trading for Certification 

1036.701 General provisions. 

1036.705 Generating and calculating emission credits. 

1036.710 Averaging and using emission credits. 

1036.715 Banking emission credits. 

1036.720 Trading emission credits. 

1036.725 What must I include in my application for certification? 

1036.730 ABT reports. 

1036.735 Recordkeeping. 

1036.740 Restrictions for using emission credits. 

1036.745 End-of-year CO2 credit deficits. 

1036.750 What can happen if I do not comply with the provisions of this subpart? 

1036.755 Information provided to the Department of Transportation. 

Subpart I—Definitions and Other Reference Information 

1036.801 Definitions. 

1036.805 Symbols, acronyms, and abbreviations. 

1036.810 Incorporation by reference. 

1036.815 What provisions apply to confidential information? 

1036.820 Requesting a hearing. 

1036.825 Reporting and recordkeeping requirements. 

Authority: 42 U.S.C. 7401 - 7671q. 

Subpart A—Overview and Applicability 
§ 1036.1 Does this part apply for my engines? 

(a) Except as specified in § 1036.5, the provisions of this part apply to all new 2014 

model year and later heavy-duty engines. This includes engines fueled by conventional 

and alternative fuels.

(b) This part does not apply with respect to exhaust emission standards for HC, CO, NOx, 

or PM except that the provisions of §1036.601 apply. 

§ 1036.2 Who is responsible for compliance? 

The regulations in this part 1036 contain provisions that affect both engine manufacturers 

and others. However, the requirements of this part are generally addressed to the engine 

manufacturer. The term "you" generally means the engine manufacturer, especially for 

issues related to certification. 

§ 1036.5 Which engines are excluded from this part’s requirements? 

(a) The provisions of this part do not apply to engines used in medium-duty passenger 

vehicles that are subject to regulation under 40 CFR part 86, subpart S, except as 

specified in 40 CFR part 86, subpart S. and §1036.108(a)(4). For example, this exclusion 

applies for engines used in vehicles certified to the standards of 40 CFR 1037.104. 

(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 parts 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. 

(c) The provisions of this part do not apply to aircraft or aircraft engines. Standards 

apply separately to certain aircraft engines, as described in 40 CFR part 87. 

(d) The provisions of this part do not apply to engines that are not internal combustion 

engines. For example, the provisions of this part do not apply to fuel cells.

(e) The provisions of this part do not apply to engines used in heavy-duty vehicles that 

are subject to light-duty greenhouse gas standards under 40 CFR part 86, subpart S, 

except as specified in 40 CFR part 86, subpart S and §1036.108(a)(4).

§ 1036.10 How is this part organized? 

This part 1036 is divided into the following subparts: 

(a) Subpart A of this part defines the applicability of this part 1036 and gives an overview 

of regulatory requirements. 

(b) Subpart B of this part describes the emission standards and other requirements that 

must be met to certify engines under this part. Note that § 1036.150 describes certain 

interim requirements and compliance provisions that apply only for a limited time. 

(c) Subpart C of this part describes how to apply for a certificate of conformity. 

(d) [Reserved] 

(e) Subpart E of this part describes provisions for testing in-use engines. 

(f) Subpart F of this part describes how to test your engines (including references to other 

parts of the Code of Federal Regulations). 

(g) Subpart G of this part describes requirements, prohibitions, and other provisions that 
apply to engine manufacturers, vehicle manufacturers, owners, operators, rebuilders, and 

all others. 

(h) Subpart H of this part describes how you may generate and use emission credits to 

certify your engines. 

(i) [Reserved] 

(j) Subpart J of this part contains definitions and other reference information. 

§ 1036.15 Do any other regulation parts apply to me? 

(a) Part 86 of this chapter describes additional requirements that apply to engines that are 

subject to this part 1036. This part extensively references portions of 40 CFR part 86. 

For example, the regulations of part 86 specify emission standards and certification 

procedures related to criteria pollutants. 

(b) Part 1037 of this chapter describes requirements for controlling evaporative emissions 

and greenhouse gas emissions from heavy-duty vehicles, whether or not they use engines 

certified under this part. It also includes standards and requirements that apply instead of 

the standards and requirements of this part in some cases. 

(c) Part 1065 of this chapter describes procedures and equipment specifications for 

testing engines to measure exhaust emissions. Subpart F of this part 1036 describes how 

to apply the provisions of part 1065 of this chapter to determine whether engines meet the 

exhaust emission standards in this part. 

(d) Certain provisions of part 1068 of this chapter apply as specified in § 1036.601 to 

everyone, including anyone who manufactures, imports, installs, owns, operates, or 

rebuilds any of the engines subject to this part 1036, or vehicles containing these engines. 

Part 1068 of this chapter describes general provisions, including that apply broadly, but 

do not necessarily apply for all engines or all persons. The issues addressed by these 

provisions include these seven areas: 

 (1) Prohibited acts and penalties for engine manufacturers, vehicle manufacturers, and 

others. 

 (2) Rebuilding and other aftermarket changes. 

 (3) Exclusions and exemptions for certain engines. 

 (4) Importing engines. 

 (5) Selective enforcement audits of your production. 

 (6) Recall. 

 (7) Procedures for hearings. 

(e) Other parts of this chapter apply if referenced in this part. 

§ 1036.30 Submission of information. 

Send all reports and requests for approval to the Designated Compliance Officer (see 

§ 1036.801). See § 1036.825 for additional reporting and recordkeeping provisions. 

Subpart B—Emission Standards and Related Requirements 

§ 1036.100 Overview of exhaust emission standards. 

Engines used in vehicles certified to the applicable chassis standards for greenhouse gas 

pollutants described in 40 CFR 1037.104 are not subject to the standards specified in this 

part. All other engines subject to this part must meet the greenhouse gas standards in 
§ 1036.108 in addition to the criteria pollutant standards of 40 CFR part 86. 

 

§ 1036.108 Greenhouse gas emission standards. 

This section contains standards and other regulations applicable to the emission of the air 

pollutant defined as the aggregate group of six greenhouse gases: carbon dioxide, nitrous 

oxide, methane, hydrofluorocarbons, perflurocarbons, and sulfur hexafluoride. This 

section describes the applicable CO2, N2O, and CH4 standards for engines. Except as 

specified in paragraph (a)(4) of this section, these standards do not apply for engines used 

in vehicles subject to (or voluntarily certified to) the CO2, N2O, and CH4 standards for 

vehicles specified in 40 CFR 1037.104. 

(a) Emission standards. Emission standards apply for engines measured using the test 

procedures specified in subpart F of this part as follows: 

(1) CO2 emission standards apply as specified in this paragraph (a)(1). For 

mediumThe applicable test cycle for measuring CO2 emissions differs depending on 

the engine family’s primary intended service class and heavy heavy-duty the extent to 

which the engines certified as will be (or were designed to be) used in tractors. For 

medium and heavy heavy-duty engines certified as tractor engines, measure CO2

emissions using only the steady-state duty cycle specified in 40 CFR 86.1362-2010

(referred to as the SET cycle). This is intended for engines designed to be used 

primarily in tractors and other line-haul applications. Note that the use of some SETcertified tractor engines in vocational applications does not affect your certification 

obligation under this paragraph; see other provisions of this part and 40 CFR part

1037 for limits on using engines certified to only one cycle. For medium and heavy 

heavy-duty engines certified as both tractors and vocationalenginesvocational 

engines, measure CO2 emissions using the steady-state duty cycle and the transient 

duty cycle (commonlysometimes referred to as the FTP engine cycle)), both of which 

are specified in 40 CFR part 86, subpart N. Note This is intended for engines that 

theare designed for use ofin both tractor engines inand vocational applications does 

not affect your certification obligation under this paragraph. For all other engines,

(including all spark-ignition engines), measure CO2 emissions using only the transient 

duty cycle specified in 40 CFR part 86, subpart N. 

(i) The CO2 standard for model year 2016 and later spark-ignition engines is 627 

g/hp-hr. 

(ii) The following CO2 standards apply for compression-ignition engines and all 

other engines (in g/hp-hr): 

Model Years Light 

HeavyDuty 

Medium HeavyDuty –

Vocational 

Heavy HeavyDuty –Vocational Medium HeavyDuty –Tractor Heavy HeavyDuty – Tractor 

2014-2016 600 600 567 502 475 

2017 and 

later 

576 576 555 487 460 

(2) The CH4 emission standard is 0.10 g/hp-hr when measured over the transient duty 

cycle specified in 40 CFR part 86, subpart N. This standard begins in model year 

2014 for compression ignition engines and in model year 2016 for spark-ignition 

engines. Note that this standard applies for all fuel types just as the other standards of 

this section do. 
(3) The N2O emission standard for all model year 2014 and later engines is 0.10 

g/hp-hr when measured over the transient duty cycle specified in 40 CFR part 86, 

subpart N. This standard begins in model year 2014 for compression ignition engines 

and in model year 2016 for spark-ignition engines. 

(4) This paragraph (a)(4) describes alternate emission standards for engines certified 

under 40 CFR 1037.150(m). The standards of paragraphs (a)(1) through (3) do not 

apply for these engines. The standards in this paragraph (a)(4) apply for emissions 

measured with the engine installed in a complete vehicle consistent with the 

provisions of 40 CFR 1037.150(m)(6). The CO2 standard for the engines equals the 

test result specified in 40 CFR 1037.150(m)(6) multiplied by 1.10 and rounded to the 

nearest 0.1 g/mile. The N2O and CH4 standards are both 0.05 g/mile (or any alternate 

standards that apply to the corresponding vehicle test group). The only requirements 

of this part that apply to these engines are those in this paragraph (a)(4) and those in 

§§1036.115 through 1036.135.

(b) Family certification levels. You must specify a CO2 Family Certification Level 

(FCL) for each engine family. The FCL may not be less than the certified emission level 

for the engine family. The CO2 Family Emission Limit (FEL) for the engine family is 

equal to the FCL multiplied by 1.03. 

(c) Averaging, banking, and trading. You may generate or use emission credits under the 

averaging, banking, and trading (ABT) program described in subpart H of this part for 

demonstrating compliance with CO2 emission standards. Credits (positive and negative) 

are calculated from the difference between the FCL and the applicable emission standard. 

As described in §1036.705, you may use CO2 credits to certify your engine families to 

FELs for N2O and/or CH4, instead of the N2O/CH4 standards of this section that 

otherwise apply. Except as specified in § 1036.150 orand 1036.705, you may not 

generate or use credits for N2O or CH4 emissions. 

(d) Useful life. Your engines must meet the exhaust emission standards of this section 

overthroughout their full useful life, expressed in service miles or calendar years, 

whichever comes first. The useful life values applicable to the criteria pollutant standards 

of 40 CFR part 86 apply for the standards of this section. 

(e) Applicability for testing. The emission standards in this subpart apply as specified in 

this paragraph (e) to all duty-cycle testing (according to the applicable test cycles),) of 

testable configurations, including certification, selective enforcement audits, and in-use 

testing. The CO2 FCLs serve as the CO2 emission standards for the engine family with 

respect to certification and confirmatory testing instead of the standards specified in 

paragraph (a)(1) of this section. The FELs serve as the emission standards for the engine 

family with respect to all other testing. See §§1036.235 and 1036.241 to determine 

which engine configurations within the engine family are subject to testing.

(f) Multi-fuel engines. For dual-fuel, multi-fuel, and flexible-fuel engines, perform 

exhaust testing on each fuel type (for example, gasoline and E85). 

(1) If we determine thatThis paragraph (f)(1) applies where you have 

demonstrateddemonstrate the relative amount of each fuel type that your engines 

consume in actual use,. Based on your demonstration, we will specify a weighting 

factor and allow you mayto submit the weighted average of your emission results. 

For example, if you certify an E85 flexible-fuel engine and we determine the engine 
will produce one-half of its work from E85 and one-half of its work from gasoline, 

you may average your E85 and gasoline emission results. 

(2) If you certify your engine family to N2O and/or CH4 FELs the FELs apply for 

testing on all fuelsfuel types for which your engine is designed, to the same extent as 

criteria emission standards apply.

§ 1036.115 Other requirements. 

(a) The warranty and maintenance requirements, adjustable parameter provisions, and 

defeat device prohibition of 40 CFR part 86 apply with respect to the standards of this 

part. 

(b) You must design and produce your engines to comply with evaporative emission 

standards as follows:

(1) For complete heavy-duty vehicles you produce, you must certify the vehicles to 

the emission standards specified in 40 CFR 1037.103.

(2) For incomplete heavy-duty vehicles and engines used in vehicles you do not 

produce, you do not need to certify your engines to evaporative emission standards or 

otherwise meet those standards. However, vehicle manufacturers certifying their 

vehicles with your engines may depend on you to produce your engines according to 

their specifications. Also, your engines must meet applicable exhaust emission 

standards in the installed configuration.

(b) [Reserved.]

§ 1036.130 Installation instructions for vehicle manufacturers. 

(a) If you sell an engine for someone else to install in a vehicle, give the engine installer 

instructions for installing it consistent with the requirements of this part. Include all 

information necessary to ensure that an engine will be installed in its certified 

configuration. 

(b) Make sure these instructions have the following information: 

 (1) Include the heading: “Emission-related installation instructions”. 

(2) State: “Failing to follow these instructions when installing a certified engine in a 

heavy-duty motor vehicle violates federal law, subject to fines or other penalties as 

described in the Clean Air Act.” 

(3) Provide all instructions needed to properly install the exhaust system and any 

other components. 

(4) Describe any necessary steps for installing any diagnostic system required under 

40 CFR part 86. 

(5) Describe how your certification is limited for any type of application. For 

example, if you certify heavy heavy-duty engines to the CO2 standards using only 

steady-state testing, you must make clear that the engine may be installed only in 

tractors. 

(6) Describe any other instructions to make sure the installed engine will operate 

according to design specifications in your application for certification. This may 

include, for example, instructions for installing aftertreatment devices when installing 

the engines. 

(7) State: “If you install the engine in a way that makes the engine’s emission control 

information label hard to read during normal engine maintenance, you must place a 
duplicate label on the vehicle, as described in 40 CFR 1068.105.” 

(c) You do not need installation instructions for engines that you install in your own 

vehicles. 

(d) Provide instructions in writing or in an equivalent format. For example, you may post 

instructions on a publicly available website for downloading or printing. If you do not 

provide the instructions in writing, explain in your application for certification how you 

will ensure that each installer is informed of the installation requirements. 

§ 1036.135 Labeling. 

Label your engines as described in 40 CFR 86.007-35(a)(3), with the following additional 

information: 

(a) State the FEL(s) to which the engines are certified under this part. If you certify your 

engines for use in both vocational and tractor applications, include the FEL for both the 

transient FTP cycle and the SET cycle.

(a) [Reserved.]

(b) Identify the emission control system. Use terms and abbreviations as described in 40 

CFR 1068.45 or other applicable conventions. 

(c) Identify any limitations on your certification. For example, if you certify heavy 

heavy-duty engines to the CO2 standards using only transient cycle testing, include the 

statement “VOCATIONAL VEHICLES ONLY”. 

(d) You may ask us to approve modified labeling requirements in this part 1036 if you 

show that it is necessary or appropriate. We will approve your request if your alternate 

label is consistent with the requirements of this part. We may also specify modified 

labeling requirement to be consistent with the intent of 40 CFR part 1037. 

§ 1036.140 Primary intended service class. 

You must identify a single primary intended service class for each compression-ignition 

engine family. Select the class that best describes vehicles for which you design and 

market the engine. The three primary intended service classes are: light heavy-duty, 

medium heavy-duty, and heavy heavy-duty. Note that provisions that apply based on 

primary intended service class often treat spark-ignition engines as if they were a separate 

service class. 

(a) Light heavy-duty engines are usually are not designed for rebuild and do not have 

cylinder liners. Vehicle body types in this group might include any heavy-duty vehicle 

built for a light-duty truck chassis, van trucks, multi-stop vans, motor homes and other 

recreational vehicles, and some straight trucks with a single rear axle. Typical 

applications would include personal transportation, light-load commercial delivery, 

passenger service, agriculture, and construction. The GVWR of these vehicles is 

normally below 19,500 pounds. 

(b) Medium heavy-duty engines may be designed for rebuild and may have cylinder 

liners. Vehicle body types in this group would typically include school buses, straight 

trucks with dual rear axles, city tractors, and a variety of special purpose vehicles such as 

small dump trucks, and refuse trucks. Typical applications would include commercial 

short haul and intra-city delivery and pickup. Engines in this group are normally used in 

vehicles whose GVWR ranges from 19,500 to 33,000 pounds. 

(c) Heavy heavy-duty engines are designed for multiple rebuilds and have cylinder liners. 
Vehicles in this group are normally tractors, trucks, and buses used in inter-city, longhaul applications. These vehicles normally exceed 33,000 pounds GVWR. 

§ 1036.150 Interim provisions.

The provisions in this section apply instead of other provisions in this part. 

(a) Early banking of greenhouse gas emissions. You may generate CO2 emission credits 

for engines you certify in model year 2013 (2015 for spark-ignition engines) to the 

standards of § 1036.108. To do so

(1)Except as specified in paragraph (a)(2) of this section, to generate early credits, 

you must certify your entire U.S.-directed production volume within that averaging 

set to these standards. If some engine families within an This means that you may not 

generate early credits while you produce engines in the averaging set that are certified 

after the start ofto the 2013 model year (2015 for spark-ignition engines), you may 

generate credits only for production that occurs after all your families are 

certifiedcriteria pollutant standards but not to the greenhouse gas standards. Calculate 

emission credits as described in subpart H of this part relative to the standard that 

would apply for model year 2014 (2016 for spark-ignition engines). 

(2) You may generate early credits for an individual compression-ignition engine

family where you demonstrate that you have improved a model year 2013 engine 

model’s CO2 emissions relative to its 2012 baseline level and certify it to an FCL 

below the applicable standard. Calculate emission credits as described in subpart H 

of this part relative to the lesser of the standard that would apply for model year 2014 

engines or the baseline engine’s CO2 emission rate. Use the smaller U.S.-directed 

production volume of the 2013 engine family or the 2012 baseline engine family. We 

will not allow you to generate emission credits under this paragraph (a)(2) unless we 

determine that your 2013 engine is the same engine as the 2012 baseline or that it 

replaces it.

(3) You may bank credits equal to the surplus credits you generate under this 

paragraph multiplied by 1.50. For example, if you have 10 Mg of surplus credits for 

model year 2013, you may bank 15 Mg of credits. Credit deficits for an averaging set 

prior to model year 2014 (2016 for spark-ignition engines) do not carry over to model 

year 2014 (2016 for spark-ignition engines). We recommend that you notify us of 

your intent to use this provision before submitting your applications. 

(b) Model year 2014 N2O standards. In model year 2014 and earlier, manufacturers may 

show compliance with the N2O standards using an engineering analysis. However, you 

may not certify to an N2O FEL different than the standard if you do not measure N2O 

emissions. This allowance also applies for later families certified using carryover CO2

data from model 2014 consistent with §1036.235(d).

(c) Engine cycle classification. Engines meeting the definition of spark-ignition, but 

regulated as diesel engines under 40 CFR part 86, must be certified to the requirements 

applicable to compression-ignition engines under this part. Such engines are deemed to 

be compression-ignition engines for purposes of this part. Similarly, engines meeting the 

definition of compression-ignition, but regulated as Otto-cycle under 40 CFR part 86 

must be certified to the requirements applicable to spark-ignition engines under this part. 

Such engines are deemed to be spark-ignition engines for purposes of this part.

(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 with 

the statement: “THIS ENGINE IS EXCLUDED UNDER 40 CFR 1037.150(c).” in order 

for this exclusion to be valid.

(e) Alternate phase-in standards. Where a manufacturer certifies all itof its model year 

2013 compression-ignition engines within a given primary intended service class to the 

applicable alternate standards of this paragraph (e), its compression-ignition engines 

within that primary intended service class are subject to the standards of this paragraph 

for model years 2013 through 2016. NoteThis means that once a manufacturer chooses 

to certify a primary intended service class to the standards of this paragraph (e), it is not 

allowed to opt out of these standards. Engines certified to these standards are not eligible 

for early credits under paragraph (a) of this section. 

Tractors LHD Engines MHD Engines HHD Engines 

Model Years 2013-

2015 

NA 512 g/hp-hr 485 g/hp-hr 

Model Years 2016 

and latera

NA 487 g/hp-hr 460 g/hp-hr 

Vocational LHD Engines MHD Engines HHD Engines 

Model Years 2013-

2015 

618 g/hp-hr 618 g/hp-hr 577 g/hp-hr 

Model Years 2016 

and later†

576 g/hp-hr 576 g/hp-hr 555 g/hp-hr 

(f) Alternate certification procedures. Manufacturers may ask us to modify the 

administrative requirements for certification for model years before 2015.

a Note: these alternate standards for 2016 and later are the same as the otherwise 

applicable standards for 2017 and later.

(f) Separate OBD families. This paragraph (f) applies where you separately certify 

engines for the purpose of applying OBD requirements (for engines used in vehicles 

under 14,000 pounds GVWR) from non-OBD engines that could be certified as a single 

engine family. You may treat the two engine families as a single engine family in certain 

respects for the purpose of this part, as specified in this paragraph (f).

(1) This paragraph applies only where the two families are identical in all respects 

except for the engine ratings offered and the inclusion of OBD.

(2) For purposes of this part and 40 CFR part 86, the two families remain two 

separate families except for the following:

(i) Specify the testable configurations of the non-OBD engine family as the 

testable configurations for the OBD family.

(ii) Submit the same CO2, N2O, and CH4 emission data for both engine families. 

(g) Assigned deterioration factors. You may use assigned deterioration factors (DFs) 

without performing your own durability emission tests or engineering analysis as 
described in this paragraph (g). 

(1) You may use an assigned additive DF of 0.0 g/hp-hr for CO2 emissions from 

engines that do not use advanced or innovative technologies. If we determine it to be 

consistent with good engineering judgment, we may allow you to use an assigned 

additive DF of 0.0 g/hp-hr for CO2 emissions from your engines with advanced or 

innovative technologies. 

(2) You may use an assigned additive DF of 0.02 g/hp-hr for N2O emissions from any 

engine. 

(3) You may use an assigned additive DF of 0.02 g/hp-hr for CH4 emissions from any 

engine. 

(h) Advanced technology credits. If you generate credits from engines certified for 

advanced technology you may multiply these credits by 1.5, except that you may not 

apply this multiplier and the early-credit multiplier of paragraph (a) of this section.(.

(i) CO2 credits for low N2O emissions. If you certify your model year 2014, 2015, or 

2016 engines to an N2O FEL less than 0.04, g/hp-hr (provided you measure N2O

emissions from your emission-data engines), you may generate additional CO2 credits 

under this paragraph (i). Calculate the additional CO2 credits from the following 

equation instead of the equation in §1036.705: 

CO2 Credits (Mg) = (0.04 – FELN2O) · (CF) · (Volume) · (UL) · (10-6) · (298) 

Subpart C—Certifying Engine Families 

§ 1036.205 What must I include in my application? 

Submit an application for certification as described in 40 CFR 86.007-21, with the 

following additional information: 

(a) Describe the engine family’s specifications and other basic parameters of the engine’s 

design and emission controls with respect to compliance with the requirements of this 

part. Describe in detail all system components for controlling greenhouse gas emissions, 

including all auxiliary emission control devices (AECDs) and all fuel-system components 

you will install on any production or test engine. Identify the part number of each 

component you describe. For this paragraph (a), treat as separate AECDs any devices 

that modulate or activate differently from each other. 

(b) Describe any test equipment and procedures that you used if you performed any tests 

that did not also involve measurement of criteria pollutants. Describe any special or 

alternate test procedures you used (see 40 CFR 1065.10(c)). 

(c) Include the emission-related installation instructions you will provide if someone else 

installs your engines in their vehicles (see § 1036.130). 

(d) Describe the label information specified in § 1036.135. We may require you to 

include a copy of the label.

(e) Identify the FCLs with which you are certifying engines in the engine family. 

Identify configurations within the family that have emission rates at or below the FCL. 

TheThe actual U.S.-directed production volume of these configurations that have 

emission rates at or below the FCL must be at least 10one 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).

(f) Identify the engine family’s deterioration factors and describe how you developed 

them (see § 1036.241). Present any test data you used for this. 

(g) Present emission data to show that you meet emission standards, as follows: 

(1) Present exhaust emission data for CO2, CH4, and N2O on an emission-data engine 

to show that your engines meet the applicable emission standards we specify in 

§ 1036.108. Show emission figures before and after applying deterioration factors for 

each engine. In addition to the composite results, show individual measurements for 

cold-start testing and hot-start testing over the transient test cycle. 

(2) Note that §§§ 1036.235 allows you to submit an application in certain cases 

without new emission data. 

(h) State whether your certification is limited for certain engines. For example, if you 

certify heavy heavy-duty engines to the CO2 standards using only transient testing, the 

engines may be installed only in vocational vehicles. 

(i) Unconditionally certify that all the engines in the engine family comply with the 

requirements of this part, other referenced parts of the CFR, and the Clean Air Act. Note 

that § 1036.235 specifies which engines to test to show that engines in the entire family 

comply with the requirements of this part. 

(j) Include the information required by other subparts of this part. For example, include 

the information required by § 1036.725 if you participate in the ABT program. 

(k(k) Include the warranty statement and maintenance instructions if we request them. 

(l) Include other applicable information, such as information specified in this part or 40 

CFR part 1068 related to requests for exemptions. 

(lm) For imported engines or equipment, identify the following: 

(1) Describe your normal practice for importing engines. For example, this may 

include identifying the names and addresses of any agents you have authorized to 

import your engines. Engines imported by nonauthorized agents are not covered by 

your certificate. 

(2) The location of a test facility in the United States where you can test your engines 

if we select them for testing under a selective enforcement audit, as specified in 40 

CFR part 1068, subpart E. 

§ 1036.210 May I get Preliminary approval before I complete my 

application?certification.

If you send us information before you finish the application, we may review it and make 

any appropriate determinations, especially for questions related to engine family 

definitions, auxiliary emission control devices, adjustable parameters, deterioration 

factors, testing for service accumulation, and maintenance. Decisions made under this 

section are considered to be preliminary approval, subject to final review and approval. 

We will generally not reverse a decision where we have given you preliminary approval, 

unless we find new information supporting a different decision. If you request

preliminary approval related to the upcoming model year or the model year after that, we 
will make best-efforts to make the appropriate determinations as soon as practicable. We 

will generally not provide preliminary approval related to a future model year more than 

two years ahead of time. 

§ 1036.225 Amending my application for certification. 

Before we issue you a certificate of conformity, you may amend your application to 

include new or modified engine configurations, subject to the provisions of this section. 

After we have issued your certificate of conformity, but before the end of the model year, 

you may send us an amended application requesting that we include new or modified 

engine configurations within the scope of the certificate, subject to the provisions of this 

section. You must amend your application if any changes occur with respect to any 

information that is included or should be included in your application. 

(a) You must amend your application before you take any of the following actions: 

(1) Add an engine configuration to an engine family. In this case, the engine 

configuration added must be consistent with other engine configurations in the engine 

family with respect to the criteria listed in § 1036.230. 

(2) Change an engine configuration already included in an engine family in a way that 

may affect emissions, or change any of the components you described in your 

application for certification. This includes production and design changes that may

affect emissions any time during the engine's lifetime. 

(3) Modify an FEL and FCL for an engine family as described in paragraph (f) of this 

section. 

(b) To amend your application for certification, send the relevant information to the 

Designated Compliance Officer. 

(1) Describe in detail the addition or change in the engine model or configuration you 

intend to make. 

(2) Include engineering evaluations or data showing that the amended engine family 

complies with all applicable requirements. You may do this by showing that the 

original emission-data engine is still appropriate for showing that the amended family 

complies with all applicable requirements. 

(3) If the original emission-data engine for the engine family is not appropriate to 

show compliance for the new or modified engine configuration, include new test data 

showing that the new or modified engine configuration meets the requirements of this 

part. 

(c) We may ask for more test data or engineering evaluations. You must give us these 

within 30 days after we request them. 

(d) For engine families already covered by a certificate of conformity, we will determine 

whether the existing certificate of conformity covers your newly added or modified 

engine. You may ask for a hearing if we deny your request (see § 1036.820). 

(e) For engine families already covered by a certificate of conformity, you may start 

producing the new or modified engine configuration anytime after you send us your 

amended application and before we make a decision under paragraph (d) of this section. 

However, if we determine that the affected engines do not meet applicable requirements, 

we will notify you to cease production of the engines and may require you to recall the 

engines at no expense to the owner. Choosing to produce engines under this paragraph 

(e) is deemed to be consent to recall all engines that we determine do not meet applicable 
emission standards or other requirements and to remedy the nonconformity at no expense 

to the owner. If you do not provide information required under paragraph (c) of this 

section within 30 days after we request it, you must stop producing the new or modified 

engines. 

(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: 

(1) You may ask to raise your FEL for your engine family at any time. In your 

request, you must show that you will still be able to meet the emission standards as 

specified in subparts B and H of this part. Use the appropriate FELs/FCLs with 

corresponding production volumes to calculate emission credits for the model year, as 

described in subpart H of this part. 

(2) You may ask to lower the FEL for your engine family only if you have test data 

from production engines showing that emissions are below the proposed lower FEL 

(or below the proposed FCL for CO2). The lower FEL/FCL applies only to engines 

you produce after we approve the new FEL/FCL. Use the appropriate FELs/FCLs 

with corresponding production volumes to calculate emission credits for the model 

year, as described in subpart H of this part. 

§ 1036.230 Selecting engine families. 

See 40 CFR 86.001-24 for instructions on how to divide your product line into families of 

engines that are expected to have similar emission characteristics throughout the useful 

life. You must certify your engines to the standards of § 1036.108 using the same engine 

families you use for criteria pollutants under 40 CFR part 86. The following provisions 

also apply: 

(a) Engines certified as hybrid engines or power packs may not be included in an engine 

family with engines with conventional powertrains. Note that this does not prevent you 

from including engines in a conventional family if they are used in hybrid vehicles, as 

long as you certify them conventionally. 

(b) If you certify engines in the family for use as both vocational and tractor engines, you 

must split your family into two separate subfamilies. Indicate in the application for 

certification that the engine family is to be split. 

(1) Calculate emission credits relative to the vocational engine standard for the 

number of engines sold into vocational applications and relative to the tractor engine 

standard for the number of engines sold into non-vocational tractor applications. You 

may assign the numbers and configurations of engines within the respective

subfamilies at any time before submitting the end-of-year report required by 

§ 1036.730. If the family participates in averaging, banking, or trading, you must

identify the type of vehicle in which each engine is installed; we may alternatively 

allow you to use statistical methods to determine this for a fraction of your engines. 

Keep records to document this determination. 
(2) If you restrict use of the test configuration for your split family to only tractors, or 

only vocational vehicles, you must identify a second testable configuration for the 

other type of vehicle (or an unrestricted configuration). Identify this configuration in 

your application for certification. The FCL for the engine family applies for this 

configuration as well as the primary test configuration. 

(c) If you certify in separate engine families engines that could have been certified in 

vocational and tractor engine subfamilies in the same engine family, count the two 

families as one family for purposes of determining your obligations with respect to the 

OBD requirements and in-use testing requirements of 40 CFR part 86. Indicate in the 

applications for certification that the two engine families are covered by this paragraph 

(c). 

(d) Engine configurations within an engine family must use equivalent greenhouse gas 

emission controls. Non-testedUnless we approve it, you may not produce nontested

configurations may not be decontented relative towithout the same emission control 

hardware included on the tested configuration in a way. We will only approve it if you 

demonstrate that increasesthe exclusion of the hardware does not increase greenhouse gas

emissions. 

§ 1036.235 Testing requirements for certification. 

This section describes the emission testing you must perform to show compliance with 

the greenhouse gas emission standards in § 1036.108. 

(a) Select a single emission-data engine from each engine family as specified in 40 CFR 

part 86. The standards of this part apply only with respect to emissions measured from 

this tested configuration and other configurations identified in §1036.205(e). Note that 

configurations identified in §1036.205(e) are considered to be “tested configurations” 

whether or not you actually tested them for certification. However, you must apply the 

same (or equivalent) emission controls to all other engine configurations in the engine 

family. 

(b) Test your emission-data engines using the procedures and equipment specified in 

subpart F of this part. In the case of dual-fuel and flexible-fuel engines, measure 

emissions when operating with each type of fuel for which you intend to certify the 

engine. Measure CO2 , CH4, and N2O emissions using the specified transient duty 

cycle,(s), including cold-start and hot-start testing as specified in 40 CFR part 86, subpart 

N. If you are certifying the engine for use only in tractors, you must measure CO2

emissions using the SET cycle. and measure CH4, and N2O emissions using the transient

cycle. If you are certifying the engine for use in vocational applications, you must 

measure CO2 , CH4, and N2O emissions using the specified transient duty cycle, including 

cold-start and hot-start testing as specified in 40 CFR part 86, subpart N. Engines 

certified for use in tractors may also be used in vocational vehicles; however, you may 

not knowingly circumvent the intent of this part (to reduce in-use emissions of CO2) by 

certifying engines designed for vocational vehicles (and rarely used in tractors) to the 

SET and not the transient cycle. For example, we would generally not allow you to 

certify all your engines to the SET without certifying any to the transient cycle. You 

may certify your engine family for both tractor and vocational use by submitting CO2

emission data from both SET and transient cycle testing and specifying FCLs for both.

(c) We may measure emissions from any of your emission-data engines. 
(1) We may decide to do the testing at your plant or any other facility. If we do this, 

you must deliver the engine to a test facility we designate. The engine you provide 

must include appropriate manifolds, aftertreatment devices, electronic control units, 

and other emission-related components not normally attached directly to the engine 

block. If we do the testing at your plant, you must schedule it as soon as possible and 

make available the instruments, personnel, and equipment we need. 

(2) If we measure emissions on your engine, the results of that testing become the 

official emission results for the engine at that test point.. Unless we later invalidate 

these data, we may decide not to consider your data at that test point in determining if 

your engine family meets applicable requirements. 

(3) Before we test one of your engines, we may set its adjustable parameters to any 

point within the physically adjustable ranges. 

(4) Before we test one of your engines, we may calibrate it within normal production 

tolerances for anything we do not consider an adjustable parameter. For example, 

this would apply for an engine parameter that is subject to production variability 

because it is adjustable during production, but is not considered an adjustable

parameter (as defined in § 1036.801) because it is permanently sealed. 

(d) You may ask to use carryover emission data from a previous model year instead of 

doing new tests, but only if all the following are true: 

(1) The engine family from the previous model year differs from the current engine 

family only with respect to model year or other characteristics unrelated to emissions. 

(2) The emission-data engine from the previous model year remains the appropriate 

emission-data engine under paragraph (b) of this section. 

(3) The data show that the emission-data engine would meet all the requirements that 

apply to the engine family covered by the application for certification. 

(e) We may require you to test a second engine of the same configuration in addition to 

the engine tested under paragraph (ba) of this section. 

(f) If you use an alternate test procedure under 40 CFR 1065.10 and later testing shows 

that such testing does not produce results that are equivalent to the procedures specified 

in subpart F of this part, we may reject data you generated using the alternate procedure. 

§ 1036.241 Demonstrating compliance with greenhouse gas pollutant standards. 

(a) For purposes of certification, your engine family is considered in compliance with the 

emission standards in § 1036.108 if all emission-data engines representing the tested 

configuration of that engine family have test results showing official emission results and 

deteriorated emission levels at or below the standards. Note that your FCLs are 

considered to be the applicable emission standards with which you must comply for 

certification. 

(b) Your engine family is deemed not to comply if any emission-data engine representing 

the tested configuration of that engine family has test results showing an official emission 

result or a deteriorated emission level for any pollutant that is above an applicable 

emission standard. (generally the FCL). Note that you may increase your FCL if any 

certification test results exceed your initial FCL. 

(c) Apply deterioration factors to the measured emission levels for each pollutant to show 

compliance with the applicable emission standards. Your deterioration factors must take 

into account any available data from in-use testing with similar engines. Apply 
deterioration factors as follows: 

(1) Additive deterioration factor for greenhouse gas emissions. Except as specified in 

paragraph (c)(2) of this section, use an additive deterioration factor for exhaust 

emissions. An additive deterioration factor is the difference between exhaust 

emissions at the end of the useful life and exhaust emissions at the low-hour test 

point. In these cases, adjust the official emission results for each tested engine at the 

selected test point by adding the factor to the measured emissions. If the factor is less 

than zero, use zero. Additive deterioration factors must be specified to one more 

decimal place than the applicable standard. 

(2) Multiplicative deterioration factor for greenhouse gas emissions. Use a 

multiplicative deterioration factor for a pollutant if good engineering judgment calls 

for the deterioration factor for that pollutant to be the ratio of exhaust emissions at the 

end of the useful life to exhaust emissions at the low-hour test point. Adjust the 

official emission results for each tested engine at the selected test point by 

multiplying the measured emissions by the deterioration factor. If the factor is less 

than one, use one. A multiplicative deterioration factor may not be appropriate in 

cases where testing variability is significantly greater than engine-to-engine 

variability. Multiplicative deterioration factors must be specified to one more 

significant figure than the applicable standard. 

(3) Sawtooth deterioration patterns. The deterioration factors described in paragraphs 

(c)(1) and (2) of this section assume that the highest useful life emissions occur either 

at the end of useful life or at the low-hour test point. The provisions of this paragraph 

(c)(3) apply where good engineering judgment indicates that the highest useful life 

emissions will occur between these two points. For example, emissions may increase 

with service accumulation until a certain maintenance step is performed, then return 

to the low-hour emission levels and begin increasing again. Such a pattern may occur 

with battery-based electric hybrid engines. Base deterioration factors for engines 

with such emission patterns on the difference between (or ratio of) the point at which 

the highest emissions occur and the low-hour test point. Note that this applies for 

maintenance-related deterioration only where we allow such critical emission-related 

maintenance. 

(d) Collect emission data using measurements to one more decimal place than the 

applicable standard. Apply the deterioration factor to the official emission result, as 

described in paragraph (c) of this section, then round the adjusted figure to the same 

number of decimal places as the emission standard. Compare the rounded emission 

levels to the emission standard for each emission-data engine. 

(e) If you identify more than one configuration in §1036.205(e), we may test (or require 

you to test) any of the identified configurations. We may also require you to provide an 

engineering analysis that demonstrates that untested configurations listed in §1036.205(e) 

comply with their FCL.

§ 1036.250 Reporting and recordkeeping for certification.

(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 engines you 

produced in each engine family during the model year (based on information available at 

the time of the report). Report the volumesproduction by serial number and engine 
configuration. Small manufacturers may omit this requirement. You may combine this 

report with reports required under subpart H of this part. 

(b) Organize and maintain the following records: 

(1) A copy of all applications and any summary information you send us. 

(2) Any of the information we specify in § 1036.205 that you were not required to

include in your application. 

(c) Keep routine data from emission tests required by this part (such as test cell 

temperatures and relative humidity readings) for one year after we issue the associated 

certificate of conformity. Keep all other information specified in this section for eight 

years after we issue your certificate. 

(d) Store these records in any format and on any media, as long as you can promptly send 

us organized, written records in English if we ask for them. You must keep these records 

readily available. We may review them at any time. 

§ 1036.255 What decisions may EPA make regarding my certificate of conformity?

(a) If we determine your application is complete and shows that the engine family meets 

all the requirements of this part and the Act, we will issue a certificate of conformity for 

your engine family for that model year. We may make the approval subject to additional 

conditions. 

(b) We may deny your application for certification if we determine that your engine 

family fails to comply with emission standards or other requirements of this part or the 

Clean Air Act. We will base our decision on all available information. If we deny your 

application, we will explain why in writing. 

(c) In addition, we may deny your application or suspend or revoke your certificate if you 

do any of the following: 

(1) Refuse to comply with any testing or reporting requirements. 

(2) Submit false or incomplete information (paragraph (e) of this section applies if 

this is fraudulent). This includes doing anything after submission of your application 

to render any of the submitted information false or incomplete. 

(3) Render inaccurate any test data. 

(4) Deny us from completing authorized activities despite our presenting a warrant or 

court order (see 40 CFR 1068.20). This includes a failure to provide reasonable 

assistance. However, you may ask us to reconsider our decision by showing that your 

failure under this paragraph (c)(4) did not involve engines related to the certificate or 

application in question to a degree that would justify our decision. 

(5) Produce engines for importation into the United States at a location where local 

law prohibits us from carrying out authorized activities. 

(6) Fail to supply requested information or amend your application to include all 

engines being produced. 

(7) Take any action that otherwise circumvents the intent of the Act or this part, with 

respect to your engine family. 

(d) We may void the certificate of conformity for an engine family if you fail to keep 

records, send reports, or give us information as required under this part or the Act. Note 

that these are also violations of §40 CFR 1068.101(a)(2). 

(e) We may void your certificate if we find that you intentionally submitted false or 

incomplete information. This includes rendering submitted information false or 
incomplete after submission. 

(f) If we deny your application or suspend, revoke, or void your certificate, you may ask 

for a hearing (see § 1036.820). 

Subpart D—[Reserved] 

Subpart E—In-use Testing 

§ 1036.401 In-use testing.

 We may perform in-use testing of any engine family subject to the standards of this part, 

consistent with the provisions of § 1036.235. Note that this provisions does not affect 

your obligation to test your in-use engines as described in 40 CFR part 86, subpart T. 

Subpart F—Test Procedures 

§ 1036.501 How do I run a valid emission test? 

(a) Use the equipment and procedures specified in 40 CFR 86.1305-2010 to determine 

whether engines meet the emission standards in § 1036.108. 

(b) You may use special or alternate procedures to the extent we allow them under 40 

CFR 1065.10. 

(c) This subpart is addressed to you as a manufacturer, but it applies equally to anyone 

who does testing for you, and to us when we perform testing to determine if your engines 

meet emission standards. 

(d) For engines that use aftertreatment technology with infrequent regeneration events, 

invalidate any test interval in which such a regeneration event occurs with respect to CO2, 

N2O, and CH4 measurements. 

(e) Test hybrid engines as described in 40 CFR part 1065 and § 1036.525. 

(f) For compression-ignition engines, use continuous sampling to determine separate 

emission rates at each test mode during the test run over the ramped-modal cycle for each 

pollutant except PM. Perform this emission sampling using good engineering judgment

by measuring emissions during the whole mode; do not measure emissions during the 

transitions between modes. Calculate emission results for each mode using the 

procedures of 40 CFR part 1065.

(f) [Reserved.] 

(g) If your engine requires special components for proper testing, you must provide any 

such components to us if we ask for them.

§ 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 

paragraph, features that recover energy between the engine and transmission are 

considered “related to engine motoring”. 

(b) If you produce a hybrid engine designed with power take-off capability and sell the 
engine coupled with a transmission, you may calculate a reduction in CO2 emissions 

resulting from the power take-off operation as described in 40 CFR 1037.525. Use good 

engineering judgment to use the vehicle-based procedures to quantify the CO2 reduction 

for your engines. 

(c) If your engine system requires special components for proper testing, you must 

provide any such components to us if we need to test your engine.

(c) The hardware that must be included in these tests is the engine, the hybrid electric 

motor, the rechargeable energy storage system (RESS) and the power electronics between 

the hybrid electric motor and the RESS. You may ask us to modify the provisions of this 

section to allow testing non-electric hybrid vehicles, consistent with good engineering 

judgment.

(d) Measure emissions using the same procedures that apply for testing non-hybrid 

engines under this part, except as specified otherwise in this part and/or 40 CFR part 

1065. The four If you test hybrid engines using the SET, deactivate the hybrid features 

unless we have specified otherwise. The five differences that apply under this section are 

related to engine mapping, engine shutdown during the test cycle, calculating work, 

limits on braking energy, and state of charge constraints.

(1) Map the engine as specified in 40 CFR 1065.510. This requires separate torque 

maps for the engine with and without the hybrid features active. For transient testing, 

denormalize the test cycle using the map generated with the hybrid feature active. 

For steady-state testing, denormalize the test cycle using the map generated with the 

hybrid feature inactive. 

(2) This paragraph applies if the engine will be configured in actual use such that the 

engine will automatically shutdown during idle operation, you may let the engine 

speed equal zero during the idle portions of the test cycle. 

(3)(i) Calculate brake energy fraction (xb)(3) Follow 1065.650(d) to calculate the 

work done over the cycle except as specified in this paragraph (d)(3). For the positive 

work over the cycle set negative power from hybrid to zero. For the negative work 

over the cycle set the positive power to zero and the set the non-hybrid power to zero. 

(4)(i) Calculate brake energy fraction, xb, as the integrated negative work over the 

cycle divided by the integrated positive work over the cycle according to equation 

1036.525-1. Calculate the brake energy limit for the engine (, xbl), according to 

equation 1036.525-2. If xb is less than xbl, continue to use the normal cycleweightedintegrated positive work for your emission calculations. If the xb is 

greater than xbl use equation 1036.525-3 to calculate the positive work done over 

the cycle. Use Wpos2Wcycle as the integrated positive work when calculating brakespecific emissions. To avoid the need to delete extra brake work from positive 

work you may set an instantaneous brake limittarget that will prevent xb from 

being larger than xbl. 

neg

b

pos

W

x

W

= Eq. 1036.525-1 

4

max 4.158 10 0.2247 bl x P −

= ⋅ ⋅ +

 

Eq. 1036.525-2 

W W W x W cycle pos neg bl pos = − − ⋅ ( )

 Eq. 1036.525-3 
(ii) The following definitions of terms apply for this paragraph (3).d)(4):

RPxb = the rated power ofbrake energy fraction.

Wneg = the engine in kWnegative work over the cycle.

Wpos = the positive work over the cycle. 

xbl = the brake energy fraction limit.

xbl = the brake energy fraction

(4Pmax = the maximum power of the engine with the hybrid system engaged (kW).

Wcycle = the work over the cycle when xb is greater than xbl.

(iii) Note that these calculations are specified with SI units (such as kW), 

consistent with 40 CFR part 1065. Emission results are converted to g/hp-hr at 

the end of the calculations.

(5) Correct for the net energy change of the energy storage feature according to the 

provisions of SAE J2711device as described in 40 CFR 1066.501. 

§ 1036.530 Calculating greenhouse gas emission rates.

This section describes how to calculate official emission results for CO2, CH4, and N2O. 

(a) Calculate brake-specific emission rates for each applicable duty cycle as specified in 

40 CFR 1065.650. Do not apply infrequent regeneration adjustment factors to your 

results. 

(b) Adjust CO2 emission rates calculated under paragraph (a) of this section for measured 

test fuel properties as specified in this paragraph (b) to obtain the official emission 

results. You are not required to apply this adjustment for fuels containing at least 75 

percent pure alcohol, such as E85. The purpose of this adjustment is to make official 

emission results independent of differences in test fuels within a fuel type. Use good 

engineering judgment to develop testing protocols and apply these provisions to 

minimize the impact of variations in test fuels. If you control test fuel properties so that

variations in the actual carbon-specific energy content are the same as or smaller than the 

repeatability of measuring carbon-specific energy content, you may use a constant value 

equal to the average carbon-specific energy content of your test fuel. and apply testing 

protocols to minimize the impact of variations in test fuels. If you use a constant value, 

you must update or verify the value at least once per year, or after changes in test fuel 

suppliers or specifications.

(1) For liquid fuels, determine the net energy content (Btu per pound of fuel) 

according to ASTM D4809 (or ASTM D240 (both incorporated by reference in 

§ 1036.810) and carbon weight fraction (dimensionless) of your test fuel according to 

ASTM D5291 (incorporated by reference in § 1036.810). (Note that we recommend 

using ASTM D4809.) For gaseous fuels, use good engineering judgment to determine 

the fuel’s net energy content and carbon weight fraction. (Note: Net energy content is 

also sometimes known as lower heating value.) Calculate the test fuel’s carbonspecific net energy content (Btu/lbC) by dividing the net energy content by the carbon 

fraction and rounding to the nearest Btu/lbC. , expressed to at least five significant 

figures. You may perform these calculations using SI units with the following 

conversion factors: one Btu equals 1055.06 Joules and one Btu/lb equals 0.0023260 

MJ/kg.
(2) If you control test fuel properties so that variations in the actual carbon-specific 

energy content are the same as or smaller than the repeatability of measuring carbonspecific energy content, you may use a constant value equal to the average carbonspecific energy content of your test fuel. Otherwise, use the measured value for the 

specific test fuel used for a given test. If you use a constant value, you must update or 

verify the value at least once per year, or after changes in test fuel suppliers or 

specifications.(2

(3) Calculate the adjustment factor for carbon-specific net energy content by dividing 

the carbon-specific net energy content of your test fuel by the reference level in the 

following table and rounding, expressed to at least five decimal places. Note that as 

used in this section, the unit lbC means pound of carbon and kgC means kilogram of 

carbon.

Fuel Type Reference carbon-specific net 

energy content (Btu/lbC) 

Reference carbon-specific net 

energy content (MJ/kgC)

Diesel fuel 21,200 49.3112

Gasoline 21,700 50.4742

Natural Gas 28,500 66.2910

LPG 24,300 56.5218

(34) Your official emission result equals your calculated brake-specific emission rate 

multiplied by the adjustment factor specified in paragraph (b)(2) of this section. For 

example, if the net energy content and carbon fraction of your diesel test fuel are 

18,400 Btu/lb and 0.870, the carbon-specific net energy content of the test fuel would 

be 21,149 Btu/lbC. The adjustment factor in the example above would be 0.99759 

(21,149/21,200). If your brake-specific CO2 emission rate was 630.0 g/hp-hr, your 

official emission result would be 628.5 g/hp-hr. 

Subpart G—Special Compliance Provisions 

§ 1036.601 What compliance provisions apply to these engines? 

(a) Engine and equipment manufacturers, as well as owners, operators, and rebuilders of 

engines subject to the requirements of this part, and all other persons, must observe the 

provisions of this part, the provisions of the Clean Air Act, and the following provisions 

of 40 CFR part 1068: 

(1) The exemption and importation provisions of 40 CFR part 1068, subparts C and 

D, apply for engines subject to this part 1036, except that the hardship exemption 

provisions of 40 CFR 1068.245, 1068.250, and 1068.255 do not apply for motor 

vehicle engines. 

(2) Manufacturers may comply with the defect reporting requirements of 40 CFR 

1068.501 instead of the defect reporting requirements of 40 CFR part 85. 

(b) Engines exempted from the applicable standards of 40 CFR part 86 are exempt from 

the standards of this part without request. 

§ 1036.610 Innovative technology credits and adjustments for reducing greenhouse 

gas emissions. 

Formatted Table

Inserted Cells
(a) You may ask us to apply the provisions of this section applies for CO2 emission 

reductions resulting from powertrain technologies that were not in common use with 

heavy-duty vehicles before model year 2010 that are not reflected in the specified test 

procedure. We may allow you to generatewill apply these provisions only for 

technologies that will result in a measurable, demonstrable, and verifiable real-world CO2

reduction. 

(b) The provisions of this section may be applied as either an improvement factor (used 

to adjust emission results) or as a separate credit, consistent with good engineering 

judgment. We recommend that you base your credit/adjustment on A to B testing of 

pairs of engines/vehicles differing only with respect to the technology in question. 

(1) Calculate improvement factors as the ratio of in-use emissions with the 

technology divided by the in-use emissions without the technology. Adjust the 

emission results by multiplying by the improvement factor. Use the improvementfactor approach where good engineering judgment indicates that the actual benefit 

will be proportional to emissions measured over the test procedures specified in this 

part. For example, the benefits from technologies that reduce engine operation would 

generally be proportional to the engine’s emission rate.

(2) Calculate separate credits based on the difference between the in-use emission rate 

(g/ton-mile) with the technology and the in-use emission rate without the technology. 

Multiply this difference by the number of engines, standard payload, and useful life. 

We may also allow you to calculate the credits based on g/hp-hr emission rates. Use 

the separate-credit approach where good engineering judgment indicates that the 

actual benefit will not be proportional to emissions measured over the test procedures 

specified in this part.

(3) We may require you to discount or otherwise adjust your improvement factor or 

credit to account for uncertainty or other relevant factors.

(c) Send your request to the Designated Compliance Officer. Include a detailed 

description of the technology and a recommended test plan. Also state whether you 

recommend applying these provisions using the improvement-factor method or the 

separate-credit method. We recommend that you do not begin collecting test data (for 

submission to EPA) before contacting us. For technologies for which the vehicle 

manufacturer could also claim credits (such as transmissions in certain circumstances), 

we may require you to include a letter from the vehicle manufacturer stating that it will 

not seek credits for the same technology.

(d) We may seek public comment on your request, consistent with the provisions of 40 

CFR 86.1866-12(d). )(3). However, we will generally not seek public comment on 

credits/adjustments based on A to B engine dynamometer testing, chassis testing, or inuse testing. 

§ 1036.615 Engines with Rankine cycle waste heat recovery and hybrid 

powertrains. 

This section specifies how to generate advanced technology-specific emission credits for 

hybrid powertrains that include energy storage systems and regenerative braking 

(including regenerative engine braking) and for engines that include Rankine-cycle (or 

other bottoming cycle) exhaust energy recovery systems. 

(a) Hybrid powertrains. This paragraph (a) applies for pre-transmission and post-
transmission hybrid powertrains. Measure

(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 effectiveness of vehicle wheels. These powertrains are tested using the hybrid 

systemengine 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 part 1037, using good engineering judgment1037.550. 

You need our approval before you begin testing. 

(b) Rankine engines. Test engines that include Rankine-cycle exhaust energy recovery 

systems according to the test procedures specified in subpart F of this part unless we 

approve alternate procedures. 

(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).§). Credits may not be generated under this 

section and 40 CFR 1037.615 for the same technology on the same vehicle.

(d) Innovative technologies. You may certify using both provisions of this section and 

the innovative technology provisions of §1036.610, provided you do not double count 

emission benefits.

§ 1036.620 Alternate CO2 standards based on model year 2011 compressionignition engines. 

For model years 2014 through 2016, you may certify your compression-ignition engines 

to the CO2 standards of this section instead of the CO2 standards in § 1036.108. 

However, you may not certify engines to these alternate standards if they are part of an 

averaging set in which you carry a balance of banked credits. You may submit 

applications for certifications before using up banked credits in the averaging set, but 

such certificates will not become effective until you have used up (or retired) your 

banked credits in the averaging set. For purposes of this section, you are deemed to carry 

credits in an averaging set if you carry credits from advanced technology that are allowed 

to be used in that averaging set. 

(a) The standards of this section are determined from the measured emission rate of the 

test engine of the applicable baseline 2011 engine family(ies) as described in paragraphs 

(b) and (c) of this section. Calculate the CO2 emission rate of the baseline test engine 

using the same equations used for showing compliance with the otherwise applicable 

standard. The alternate CO2 standard for light and medium heavy-duty FTPvocationalcertified (vocational) engines (certified for CO2 using the transient cycle) is equal to the 

baseline emission rate multiplied by 0.975. The alternate CO2 standard for SET-certified 

(tractor)-certified engines (certified for CO2 using the SET cycle) and all other heavy 

heavy-duty engines is equal to the baseline emission rate multiplied by 0.970. The in-use 

FEL for these engines is equal to the alternate standard multiplied by 1.03. 

(b) This paragraph (b) applies if you do not certify all your engine families in the 

averaging set to the alternate standards of this section. Identify separate baseline engine 
families for each engine family that you are certifying to the alternate standards of this 

section. For an engine family to be considered the baseline engine family, it must meet 

the following criteria: 

(1) It must have been certified to all applicable emission standards in model year 

2011. If it the baseline engine was certified to a NOx FEL above the standard and 

incorporated the same emission control technologies as the new engine family, you 

may adjust the baseline CO2 emission rate to be equivalent to an engine meeting the 

0.20 g/hp-hr NOx standard, (or your higher FEL as specified in this paragraph (b)(1)),

using certification results from model years 20009 through 2011, consistent with 

good engineering judgment. Use the following equation to relate NOx and CO2 

emission rates (g/hp-hr): CO2 = a•log(NOx)+b.

(i) Use the following equation to relate model year 2009-2011 NOx and CO2

emission rates (g/hp-hr): CO2 = a×log(NOx)+b. 

(ii) For model year 2014-2016 engines certified to NOx FELs above 0.20 g/hp-hr, 

correct the baseline CO2 emissions to the actual NOx FELs of the 2014-2016

engines. 

(iii) Calculate separate adjustments for transient and SET emissions.

(2) The baseline configuration tested for certification must have the same engine 

displacement as the engines in the engine family being certified to the alternate 

standards, and its rated power must be within 5five percent of the highest rated power 

in the engine family being certified to the alternate standards. 

(3) The model year 2011 U.S.-directed production volume of the configuration tested 

must be at least 10one percent of the total 2011 U.S.-directed production volume for 

the engine family. 

(4) The tested configuration must have cycle-weighted BSFC equivalent to or better 

than all other configurations in the engine family. 

(c) This paragraph (c) applies if you certify all your engine families in the averaging 

setprimary intended service class to the alternate standards of this section. For purposes 

of this section, you may combine light heavy-duty and medium heavy-duty engines into a 

single averaging set. Determine your baseline CO2 emission rate as the salesproductionweighted emission rate of the certified enginesengine families you produced in the 2011 

model year. If you produce engines for both tractors and vocational vehicles, treat FTPcertified and SET-certified engines them as separate averaging sets. Adjust the CO2

emission rates to be equivalent to an engine meeting the average NOx FEL of new 

engines (assuming engines certified to the 0.20 g/hp-hr NOx standard have a NOx FEL 

equal to 0.20 g/hp-hr), as described in paragraph (b)(1) of this section. 

(d) Include the following statement on the emission control information label: “THIS 

ENGINE WAS CERTIFIED TO AN ALTERNATE CO2 STANDARD UNDER 

§ 1036.620.” 

(e) You may not bank CO2 emission credits for any engine family in the same averaging 

set and model year in which you certify engines to the standards of this section. This 

means You may not bank any advanced technology credits in any averaging set for the

model year you certify under this section. (since such credits would be available for use 

in this averaging set). Note that the provisions of §1036.745 apply with respect tofor

deficits generated with respect to the standards of this section. 

(f) You need our approval before you may certify engines under this section, especially 
with respect to the numerical value of the alternate standards. We will not approve your 

request if we determine that you manipulated your engine families, or tested enginestest 

engine configurations to certify to less stringent standards, or that you otherwise have not 

acted in good faith. You must keep and provide to us any information we need to 

determine that your engine families meet the requirements of this section. Keep these 

records for at least five years after you stop producing engines certified under this 

section. 

Subpart H—Averaging, Banking, and Trading for Certification

§ 1036.701 General provisions.

(a) 1036.625 In-use compliance with family emission limits (FELs).

You may use averaging, banking,ask us to apply a higher in-use FEL for certain in-use 

engines, subject to the provisions of this section. Note that §1036.225 contains 

provisions related to changing FELs during a model year.

(a) Purpose. This section is intended to address circumstances in which it is in the public 

interest to apply a higher in-use FEL based on forfeiting an appropriate number of 

emission credits. 

(b) FELs. When applying higher in-use FELs to your engines, we would intend to 

accurately reflect the actual in-use performance of your engines, consistent with the 

specified testing provisions of this part.

(c) Equivalent families. We may apply the higher FELs to other families in other model 

years if they used equivalent emission controls.

(d) Credit forfeiture. Where we specify higher in-use FELs under this section, you must 

forfeit CO2 emission credits based on the difference between the in-use FEL and the 

otherwise applicable FEL. Calculate the amount of credits to be forfeited using the 

applicable equation in §1036.705, by substituting the otherwise applicable FEL for the 

standard and the in-use FEL for the otherwise applicable FEL.

(e) Requests. Submit your request to the Designated Compliance Officer. Include the 

following in your request:

(1) The engine family name and model year of the engines affected.

(2) A list of other engine families/model years that may be affected.

(3) The otherwise applicable FEL for the engine families along with your

recommendations for higher in-use FELs.

(4) Your source of credits for forfeiture. 

(f) Relation to recall. You may not request higher in-use FELs for any engine families 

for which we have made a determination of nonconformance and ordered a recall. You 

may, however, make such requests for engine families for which you are performing a 

voluntary emission recall.

(g) Approval. We may approve your request if we determine that you meet the 

requirements of this section and such approval is in the public interest. We may include 

appropriate conditions with our approval or we may approve your request with 

modifications.

Subpart H—Averaging, Banking, and Trading for Certification
§ 1036.701 General provisions.

trading (ABT)(a) You may average, bank, and trade (ABT) emission credits for purposes 

of certification as described in this subpart and in subpart B of this part to show 

compliance with the standards of § 1036.108. Participation in this emission credit 

program is voluntary. (Note: As described in subpart B of this part, you must assign an 

FCL to all engine families, whether or not they participate in the ABT provisions of this 

subpart.) 

(b) [Reserved] 

(c) The definitions of subpart I of this part apply to this subpart. The following 

definitions also apply: 

(1) Actual emission credits means emission credits you have generated that we have 

verified by reviewing your final report. 

(2) Averaging set means a set of engines in which emission credits may be 

exchanged. Credits generated by one engine may only be used by other engines in 

the same averaging set. See § 1036.740. 

(3) Broker means any entity that facilitates a trade of emission credits between a 

buyer and seller. 

(4) Buyer means the entity that receives emission credits as a result of a trade. 

(5) Reserved emission credits means emission credits you have generated that we 

have not yet verified by reviewing your final report. 

(6) Seller means the entity that provides emission credits during a trade. 

(7) Standard means the emission standard that applies under subpart B of this part for 

engines not participating in the ABT program of this subpart. 

(8) Trade means to exchange emission credits, either as a buyer or seller. 

(d) Emission credits may be exchanged only within an averaging set as specified in 

§ 1036.740. 

(e) You may not use emission credits generated under this subpart to offset any emissions 

that exceed an FCL or standard. This applies for all testing, including certification 

testing, in-use testing, selective enforcement audits, and other production-line testing. 

However, if emissions from an engine exceed an FCL or standard (for example, during a 

selective enforcement audit), you may use emission credits to recertify the engine family 

with a higher FCL that applies only to future production. 

(f) Emission credits may be used in the model year they are generated or in future model 

years. . Surplus emission credits may notbe banked for future model years. Surplus 

emission credits may sometimes be used for past model years, except as 

specifieddescribed in §1036.745. 

(g) You may increase or decrease an FCL during the model year by amending your 

application for certification under § 1036.225. The new FCL may apply only to engines 

you have not already introduced into commerce. Each engine’s emission control 

information label must include the applicable FELs.

(h) You may donate or selltrade 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 § 1036.725730. 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.
(i) See §1036.745740 for special credit provisions that apply for credits generated under 

§1036.615 or 40 CFR 1037.104(d)(7) or 1037.615.

(j) Unless the regulations explicitly allow it, you to have a negative credit balance for up 

to three consecutive model years with respect tomay not calculate credits more than once 

for any emission reduction. For example, if you generate CO2 emissions. emission 

credits for a hybrid engine under this part for a given vehicle, no one may generate CO2

emission credits for that same hybrid engine and vehicle under 40 CFR part 1037. 

However, credits could be generated for identical vehicles using engines that did not 

generate credits under this part.

§ 1036.705 Generating and calculating emission credits.

(a) The provisions of this section apply separately for calculating emission credits for 

each pollutant. 

(b) For each participating family, calculate positive or negative emission credits relative 

to the otherwise applicable emission standard based on the engine family’s FCL for 

greenhouse gases. If your engine family is certified to both the vocational and tractor 

engine standards, calculate credits separately for the vocational engines and the tractor 

engines (as specified in paragraph (b)(3) of this section). Calculate positive emission 

credits for a family that has an FCL below the standard. Calculate negative emission 

credits for a family that has an FCL above the standard. 

Sum your positive and negative credits for the model year before rounding. Round the 

sum of emission credits to the nearest megagram (Mg), using consistent units throughout 

the following equations: 

(1) For vocational engines: 

Emission credits (Mg) = (Std – FCL) · (CF) · (Volume) · (UL) · (10-6) 

Where: 

Std = the emission standard, in g/hp-hr, that applies under subpart B of this part 

for engines not participating in the ABT program of this subpart (the 

“otherwise applicable standard”). 

FCL = the Family Certification Level for the engine family, in g/hp-hr, measured 

over the transient duty cycle, rounded to the same number of decimal places 

as the emission standard. 

CF = a transient cycle conversion factor (hp-hr/mile), calculated by dividing the 

total (integrated) horsepower-hour over the duty cycle (average of vocational 

engine configurations weighted by their production volumes) by 6.3 miles for 

spark-ignition engines and 6.5 miles for compression-ignition engines. This 

represents the average work performed by vocational engines in the family

over the mileage represented by operation over the duty cycle. 

Volume = the number of vocational engines eligible to participate in the 

averaging, banking, and trading program within the given engine family 

during the model year, as described in paragraph (c) of this section. 

UL = the useful life for the given engine family, in miles.UL = the useful life for 

the given engine family, in miles.

(2) For tractor engines: 

Emission credits (Mg) = (Std – FCL) · (CF) · (Volume) · (UL) · (10-6) 

Where: 
Std = the emission standard, in g/hp-hr, that applies under subpart B of this part 

for engines not participating in the ABT program of this subpart (the 

“otherwise applicable standard”). 

FCL = the Family Certification Level for the engine family, in g/hp-hr, measured 

over the SET duty cycle rounded to the same number of decimal places as the 

emission standard. 

CF = thea transient cycle conversion factor (hp-hr/mile), calculated under 

paragraph (b)(1)by dividing the total (integrated) horsepower-hour over the 

duty cycle (average of tractor-engine configurations weighted by their 

production volumes) by 6.3 miles for spark-ignition engines and 6.5 miles for 

compression-ignition engines. This represents the average work performed by 

tractor engines in the family over the mileage represented by operation over 

the duty cycle. Note that this section. 

calculation requires you to use the transient cycle conversion factor even for 

engines certified to SET-based standards. Volume = the number of tractor 

engines eligible to participate in the averaging, banking, and trading program 

within the given engine family during the model year, as described in 

paragraph (c) of this section. 

UL = the useful life for the given engine family, in miles. 

(3)(3) For engine families certified to both the vocational and tractor engine 

standards, we may allow you to use statistical methods to estimate the total 

production volumes where a small fraction of the engines cannot be tracked precisely. 

(4) You may not generate emission credits for tractor engines (i.e., engines not 

certified to the transient cycle for CO2) installed in vocational vehicles (including 

vocational tractors certified pursuant to 40 CFR 1037.630 or exempted pursuant to 40 

CFR 1037.631). We will waive this requirement where you demonstrate that less 

than five percent of the engines in your tractor family were installed in vocational 

vehicles. For example, if you know that 96 percent of your tractor engines were 

installed in non-vocational tractors, but cannot determine the vehicle type for the 

remaining four percent, you may generate credits for all the engines in the family. 

(c) As described in § 1036.730, compliance with the requirements of this subpart is 

determined at the end of the model year based on actual U.S.-directed production 

volumes. Keep appropriate records to document these production volumes. Do not 

include any of the following engines to calculate emission credits: 

(1) Engines(1) Engines that you do not certify to the CO2 standards of this part 

because they are permanently exempted under subpart G of this part or under 40 CFR 

part 1068. 

(2) Exported engines. 

(3) Engines not subject to the requirements of this part, such as those excluded under 

§ 1036.5. For example, do not include engines used in vehicles certified to the 

greenhouse gas standards of 40 CFR 1037.104. 

(4) [Reserved] 

(5) Any other engines if we indicate elsewhere in this part 1036 that they are not to be 

included in the calculations of this subpart. 

(d) You may use CO2 emission credits to show compliance with CH4 and/or N2O FELs 

instead of the otherwise applicable emission standards. To do this, calculate the CH4
and/or N2O emission credits needed (negative credits) using the equation in paragraph (b) 

of this section, using the FEL(s) you specify for your engines during certification. instead 

of the FCL. You must use 25 Mg of positive CO2 credits to offset 1 Mg of negative CH4

credits. You must use 298 Mg of positive CO2 credits to offset 1 Mg of negative N2O 

credits. 

§ 1036.710 Averaging and using emission credits..

(a) Averaging is the exchange of emission credits among your engine families. You may 

average emission credits only within the same averaging set. 

(b) You may certify one or more engine families to an FCL above the applicable 

standard, subject to any applicable FEL caps and other the provisions in subpart B of this 

part, if you show in your application for certification that your projected balance of all 

emission-credit transactions in that model year is greater than or equal to zero, or that a 

negative balance is allowed under § 1036.745. 

(c) If you certify an engine family to an FCL that exceeds the otherwise applicable 

standard, you must obtain enough emission credits to offset the engine family’s deficit by 

the due date for the final report required in § 1036.730. The emission credits used to 

address the deficit may come from your other engine families that generate emission 

credits in the same model year, (or from later model years as specified in § 1036.745),

from emission credits you have banked, or from emission credits you obtain through 

trading. 

§ 1036.715 Banking emission credits. 

(a) Banking is the retention of surplus emission credits by the manufacturer generating 

the emission credits for use in future model years for averaging or trading. 

(b) You may designate any emission credits you plan to bank in the reports you submit 

under § 1036.730 as reserved credits. During the model year and before the due date for 

the final report, you may designate your reserved emission credits for averaging or 

trading. 

(c) Reserved credits become actual emission credits when you submit your final report. 

However, we may revoke these emission credits if we are unable to verify them after 

reviewing your reports or auditing your records. 

(d) Banked credits retain the designation of the averaging set in which they were 

generated.

§ 1036.720 Trading emission credits. 

(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 may be used 

only withinremain subject to the averaging-set restrictions based on the averaging set in 

which they were generated, except as allowed under § 1036.745. 

(b) You may trade actual emission credits as described in this subpart. You may also 

trade reserved emission credits, but we may revoke these emission credits based on our 

review of your records or reports or those of the company with which you traded 

emission credits. You may trade banked credits within an averaging set to any certifying 

manufacturer. 
(c) If a negative emission credit balance results from a transaction, both the buyer and 

seller are liable, except in cases we deem to involve fraud. See § 1036.255(e) for cases 

involving fraud. We may void the certificates of all engine families participating in a 

trade that results in a manufacturer having a negative balance of emission credits. See 

§ 1036.745. 

§ 1036.725 What must I include in my application for certification? 

(a) You must declare in your application for certification your intent to use the provisions 

of this subpart for each engine family that will be certified using the ABT program. You 

must also declare the FELs/FCL you select for the engine family for each pollutant for 

which you are using the ABT program. Your FELs must comply with the specifications 

of subpart B of this part, including the FEL caps. FELs/FCL must be expressed to the 

same number of decimal places as the applicable standards. 

(b) Include the following in your application for certification: 

(1) A statement that, to the best of your belief, you will (or will not) have a negative 

balance of emission credits for any averaging set when all emission credits are 

calculated at the end of the year; or a statement that you will have a negative balance 

of emission credits for one or more averaging sets, but that it is allowed under 

§ 1037.745. 

(2) Detailed calculations of projected emission credits (positive or negative) based on 

projected U.S.-directed production volumes. We may require you to include similar 

calculations from your other engine families to demonstrate that you will be able to 

avoid negativeproject your net credit balances for the model year. If you project 

negative emission credits for a family, state the source of positive emission credits 

you expect to use to offset the negative emission credits. 

§ 1036.730 ABT reports. 

(a) If any of your engine 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. We may waive the 

requirement to send the end-of year report, conditioned upon you sending the final report 

on time. However, we will not waive this requirement where you have a deficit for that 

model year or an outstanding deficit for an earlier model year. 

(b) Your end-of-year and final reports must include the following information for each 

engine family participating in the ABT program: 

(1) Engine-family designation and averaging set. 

(2) The emission standards that would otherwise apply to the engine family. 

(3) The FCL for each pollutant. If you change the FCL after the start of production, 

identify the date that you started using the new FCL and/or give the engine 

identification number for the first engine covered by the new FCL. In this case, 

identify each applicable FCL and calculate the positive or negative emission credits 

as specified in § 1036.225. 

(4) The projected and actual U.S.-directed production volumes for the model year. If 

you changed an FCL during the model year, identify the actual production volume 

associated with each FCL. 

(5) The transient cycle conversion factor for each engine configuration as described in 
§ 1036.705. 

(6) Useful life. 

(7) Calculated positive or negative emission credits for the whole engine family. 

Identify any emission credits that you traded, as described in paragraph (d)(1) of this 

section. 

(c) Your end-of-year and final reports must include the following additional information: 

(1) Show that your net balance of emission credits from all your participating engine 

families in each averaging set in the applicable model year is not negative, except as 

allowed under § 1036.745. 

(2) State whether you will reserve any emission credits for banking.

(3) State that the report’s contents are accurate. 

(d) If you trade emission credits, you must send us a report within 90 days after the 

transaction, as follows: 

 (1) As the seller, you must include the following information in your report: 

(i) The corporate names of the buyer and any brokers. 

(ii) A copy of any contracts related to the trade. 

 (iii) The engine families that generated emission credits for the trade, including 

the number of emission credits from each family. 

(2) As the buyer, you must include the following information in your report: 

(i) The corporate names of the seller and any brokers. 

(ii) A copy of any contracts related to the trade. 

 (iii) How you intend to use the emission credits, including the number of emission 

credits you intend to apply to each engine family (if known). 

(e) Send your reports electronically to the Designated Compliance Officer using an 

approved information format. If you want to use a different format, send us a written 

request with justification for a waiver. 

(f) Correct errors in your end-of-year report or final report as follows: 

(1) You may correct any errors in your end-of-year report when you prepare the final 

report, as long as you send us the final report by the time it is due. 

(2) If you or we determine within 270 days after the end of the model year that errors 

mistakenly decreased your balance of emission credits, you may correct the errors 

and recalculate the balance of emission credits. You may not make these corrections 

for errors that are determined more than 270 days after the end of the model year. If 

you report a negative balance of emission credits, we may disallow corrections under 

this paragraph (f)(2). 

(3) If you or we determine anytime that errors mistakenly increased your balance of 

emission credits, you must correct the errors and recalculate the balance of emission 

credits. 

§ 1036.735 Recordkeeping.

(a) You must organize and maintain your records as described in this section. We may 

review your records at any time. 

(b) Keep the records required by this section for at least eight years after the due date for 

the end-of-year report. You may not use emission credits for any engines if you do not 

keep all the records required under this section. You must therefore keep these records to 

continue to bank valid credits. Store these records in any format and on any media, as 
long as you can promptly send us organized, written records in English if we ask for 

them. You must keep these records readily available. We may review them at any time. 

(c) Keep a copy of the reports we require in §§ 1036.725 and 1036.730. 

(d) Keep records of the engine identification number (usually the serial number) for each 

engine you produce that generates or uses emission credits under the ABT program. You 

may identify these numbers as a range. If you change the FEL after the start of 

production, identify the date you started using each FCL and the range of engine 

identification numbers associated with each FCL. You must also identify the purchaser 

and destination for each engine you produce to the extent this information is available. 

(e) We may require you to keep additional records or to send us relevant information not 

required by this section in accordance with the Clean Air Act. 

§ 1036.740 Restrictions for using emission credits.

The following restrictions apply for using emission credits: 

(a) Averaging sets. Except as specified in paragraph (c) of this section, emission credits 

may be exchanged only within thean following averaging sets There are four principal 

averaging sets for engines subject to this subpart: 

(1) Spark-ignition engines. 

(2) Compression-ignition light heavy-duty engines. 

(3) Compression-ignition medium heavy-duty engines. 

(4) Compression-ignition heavy heavy-duty engines. 

(b) Applying credits to prior year deficits. Where your credit balance for the previous 

year is negative, you may apply credits to that credit deficit only after meeting your credit 

obligations for the current year. 

(c) Credits from hybridshybrid engines and other advanced technologies. The averaging 

set restrictions of paragraph (a) of this section do not apply for credits generated under 

§1036.615 or 40 CFR 1037.610104(d)(7) or 1037.615 from hybrid engine power systems 

with regenerative braking, or from other advanced technologies. Such credits may also 

be used under 40 CFR part 1037, provided they are converted using good engineering 

judgment to be equivalent to credits calculated under that part. The maximum amount of 

credits you may bring into an averaging set is 40,000 Mg per model year..

(d) Credit life.(1)The maximum amount of credits you may bring into the following 

service class groups is 60,000 Mg per model year: 

(i) Spark-ignition engines, light heavy-duty compression-ignition engines, and 

light heavy-duty vehicles. This group comprises the averaging sets listed in 

paragraphs(a)(1) and (2) of this section and the averaging set listed in 40 CFR

1037.740(a)(1). 

(ii) Medium heavy-duty compression-ignition engines and medium heavy-duty 

vehicles. This group comprises the averaging sets listed in paragraph (a)(3) of 

this section and 40 CFR 1037.740(a)(2).

(iii) Heavy heavy-duty compression-ignition engines and heavy heavy-duty 

vehicles. This group comprises the averaging sets listed in paragraph (a)(4) of 

this section and 40 CFR 1037.740(a)(3).

(2) The limit specified in paragraph (c)(1) of this section does not limit the amount of 

advanced technology credits that can be used within a service class group if they were 

generated in that same service class group.(d) Credit life. Credits expire after five 
years. 

(e) Other restrictions. Other sections of this part specify additional restrictions for using 

emission credits under certain special provisions. 

§ 1036.745 End-of-year CO2 credit deficits. 

Except as allowed by this section, we may void the certificate of any engine family 

certified to an FCL above the applicable standard is void iffor which you do not have 

sufficient credits by the deadline for submitting the final report. 

(a) Your certificate for an engine family for which you do not have sufficient CO2 credits 

will not be void if you remedy the deficit with surplus credits within three model years. 

For example, if you have a credit deficit of 500 Mg for an engine family at the end of 

model year 2015, you must generate (or otherwise obtain) a surplus of at least 500 Mg in 

that same averaging set by the end of model year 2018. 

(b) You may not bank or trade away CO2 credits in the averaging set in any model year in 

which you have a deficit. 

(c) You may only apply only surplus credits to your deficit. You may not apply credits to 

a deficit from an earlier model year if the new credits arethey were generated in a model 

year infor which you have a net credit deficit at the endany of the year your engine 

families for that averaging set had an end-of-year credit deficit. 

(d) If you do not remedy the deficit with surplus credits within three model years, we 

may void your certificate is void for that engine family. We may void the certificate 

based on your end-of-year report. Note that voiding a certificate applies ab initio (i.e., 

retroactively).. Where the net deficit is less than the total amount of negative credits 

originally generated by the family, we will only void the certificate only with respect to 

enoughthe number of engines needed to reach the amount of the net deficit. For example, 

if the original engine family generated 500 Mg of negative credits, and the 

manufacturer’s net deficit after three years was 250 Mg, we would void the certificate 

with respect to half of the engines in the family. 

§ 1036.750 What can happen if I do not comply with the provisions of this subpart? 

(a) For each engine family participating in the ABT program, the certificate of 

conformity is conditioned upon full compliance with the provisions of this subpart during 

and after the model year. You are responsible to establish to our satisfaction that you 

fully comply with applicable requirements. We may void the certificate of conformity 

for an engine family if you fail to comply with any provisions of this subpart. 

(b) You may certify your engine family to an FCL above an applicable standard based on 

a projection that you will have enough emission credits to offset the deficit for the engine 

family. However, we may void the certificate of conformity See §1036.745 for 

provisions specifying what happens if you cannot show in your final report that you have 

enough actual emission credits to offset a deficit for any pollutant in an engine family. 

(c) We may void the certificate of conformity for an engine family if you fail to keep 

records, send reports, or give us information we request. Note that failing to keep 

records, send reports, or give us information we request is also a violation of 42 U.S.C. 

7522(a)(2). 

(d) You may ask for a hearing if we void your certificate under this section (see 

§ 1036.820). 
§ 1036.755 Information provided to the Department of Transportation. 

(a) We may require you to submit a pre-certification compliance report to us for the 

upcoming model year or the year after the upcoming model year.

(b) After receipt of each manufacturer’s final report as specified in § 1036.730 and 

completion of any verification testing required to validate the manufacturer’s submitted 

final data, we will issue a report to the Department of Transportation with CO2 emission 

information and will verify the accuracy of theeach manufacturer’s equivalent fuel 

consumption data that must be reportedrequired by NHTSA inunder 49 CFR 535.8. We 

will send a report to DOT for each engine manufacturer based on each regulatory 

category and subcategory, including sufficient information for NHTSA to determine fuel 

consumption and associated credit values. See 49 CFR 535.8 to determine if NHTSA 

deems submission of this information to EPA to also be a submission to NHTSA. 

Subpart I—Definitions and Other Reference Information 

§ 1036.801 Definitions. 

 The following definitions apply to this part. The definitions apply to all subparts 

unless we note otherwise. All undefined terms have the meaning the Act gives to them. 

The definitions follow: 

 Act means the Clean Air Act, as amended, 42 U.S.C. 7401 - 7671q. 

 Adjustable parameter has the meaning given in 40 CFR part 86. 

 Advanced technology means technology certified under §1036.615., 40 CFR 

1037.104(d)(7) or 1037.615.

Innovative technology means technology certified under §1036.610.

 Aftertreatment means relating to a catalytic converter, particulate filter, or any other 

system, component, or technology mounted downstream of the exhaust valve (or exhaust 

port) whose design function is to decrease emissions in the engine exhaust before it is 

exhausted to the environment. Exhaust-gas recirculation (EGR) and turbochargers are 

not aftertreatment. 

 Aircraft means any vehicle capable of sustained air travel above treetop heights. 

 Alcohol-fueled engine mean an engine that is designed to run using an alcohol fuel. 

For purposes of this definition, alcohol fuels do not include fuels with a nominal alcohol 

content below 25 percent by volume. 

 Auxiliary emission control device means any element of design that senses 

temperature, motive speed, engine RPM, transmission gear, or any other parameter for 

the purpose of activating, modulating, delaying, or deactivating the operation of any part 

of the emission control system. 

 Averaging set has the meaning given in § 1036.701740. 

 Calibration means the set of specifications and tolerances specific to a particular 

design, version, or application of a component or assembly capable of functionally 

describing its operation over its working range. 

 Carryover means relating to certification based on emission data generated from an 

earlier model year as described in § 1036.235(d). 

 Certification means relating to the process of obtaining a certificate of conformity for 

an engine family that complies with the emission standards and requirements in this part. 
 Certified emission level means the highest deteriorated emission level in an engine 

family for a given pollutant from either transient or steady-state testing. the applicable 

transient and/or steady-state testing, rounded to the same number of decimal places as the

applicable standard. Note that you may have two certified emission levels for CO2 if 

you certify a family for both vocational and tractor use.

 Complete vehicle means a vehicle meeting the definition of complete vehicle in 40 

CFR 1037.801 when it is first sold as a vehicle. For example, where a vehicle 

manufacturer sells an incomplete vehicle to a secondary manufacturer, the vehicle is not a 

complete vehicle under this part, even after its final assembly. 

 Compression-ignition means relating to a type of reciprocating, internal-combustion 

engine that is not a spark-ignition engine. 

 Crankcase emissions means airborne substances emitted to the atmosphere from any 

part of the engine crankcase’s ventilation or lubrication systems. The crankcase is the 

housing for the crankshaft and other related internal parts. 

 Criteria pollutants means emissions of NOx, HC, PM, and CO. Note that these 

pollutants are also sometimes described collectively as “non-greenhouse gas pollutants”, 

although they do not necessarily have negligible global warming potentials.

 Designated Compliance Officer means the Manager, Heavy-Duty and Nonroad 

Engine Group (6405-J), U.S. Environmental Protection Agency, 1200 Pennsylvania Ave., 

NW., Washington, DC 20460. 

 Designated Enforcement Officer means the Director, Air Enforcement Division 

(2242A), U.S. Environmental Protection Agency, 1200 Pennsylvania Ave., NW., 

Washington, DC 20460. 

 Deteriorated emission level means the emission level that results from applying the 

appropriate deterioration factor to the official emission result of the emission-data engine. 

Note that where no deterioration factor applies, references in this part to the deteriorated 

emission level mean the official emission result. 

 Deterioration factor means the relationship between emissions at the end of useful life 

(or point of highest emissions if it occurs before the end of useful life) and emissions at 

the low-hour/low-mileage test point, expressed in one of the following ways: 

(1) For multiplicative deterioration factors, the ratio of emissions at the end of useful life 

(or point of highest emissions) to emissions at the low-hour test point. 

(2) For additive deterioration factors, the difference between emissions at the end of 

useful life (or point of highest emissions) and emissions at the low-hour test point. 

 Dual-fuel means relating to an engine designed for operation on two different types of 

fuel but not on a continuous mixture of those fuels. 

 Emission control system means any device, system, or element of design that controls 

or reduces the emissions of regulated pollutants from an engine. 

 Emission-data engine means an engine that is tested for certification. This includes 

engines tested to establish deterioration factors. 

 Emission-related maintenance means maintenance that substantially affects emissions 

or is likely to substantially affect emission deterioration. 

 Engine configuration means a unique combination of engine hardware and calibration 

(related to the emission standards) within an engine family. Engines within a single 

engine configuration differ only with respect to normal production variability or factors 

unrelated to emissionscompliance with emission standards. 
 Engine family has the meaning given in § 1036.230. 

 Excluded means relating to engines that are not subject to some or all of the 

requirements of this part as follows: 

(1) An engine that has been determined to not to be a heavy-duty engine is excluded from 

this part. 

(2) Certain heavy-duty engines are excluded from the requirements of this part under 

§ 1036.5. 

(3) Specific regulatory provisions of this part may exclude a heavy-duty engine generally 

subject to this part from one or more specific standards or requirements of this part. 

 Exempted has the meaning given in 40 CFR 1068.30. 

 Exhaust-gas recirculation means a technology that reduces emissions by routing 

exhaust gases that had been exhausted from the combustion chamber(s) back into the 

engine to be mixed with incoming air before or during combustion. The use of valve 

timing to increase the amount of residual exhaust gas in the combustion chamber(s) that 

is mixed with incoming air before or during combustion is not considered exhaust-gas 

recirculation for the purposes of this part. 

 Family certification level (FCL) means a CO2 emission level declared by the 

manufacturer that is at or above emission test results for all emission-data engines. The 

FCL serves as the emission standard for the engine family with respect to certification 

testing if it is different than the otherwise applicable standard. The FCL must be 

expressed to the same number of decimal places as the emission standard it replaces. 

 Family emission limit (FEL) means an emission level declared by the manufacturer to 

serve in place of an otherwise applicable emission standard (other than CO2 standards) 

under the ABT program in subpart H of this part. The FEL must be expressed to the 

same number of decimal places as the emission standard it replaces. The FEL serves as 

the emission standard for the engine family with respect to all required testing except 

certification testing for CO2. The CO2 FEL is equal to the CO2 FCL multiplied by 

1.030003 and rounded to the same number of decimal places as the standard. (e.g., the 

nearest whole g/hp-hr for the 2016 CO2 standards). 

 Flexible-fuel means relating to an engine designed for operation on any mixture of 

two or more different types of fuels. 

 Fuel type means a general category of fuels such as diesel fuel, gasoline, or natural

gas. There can be multiple grades within a single fuel type, such as premium gasoline, 

regular gasoline, or gasoline with 10 percent ethanol. 

 Good engineering judgment has the meaning given in 40 CFR 1068.30. See 40 CFR 

1068.5 for the administrative process we use to evaluate good engineering judgment. 

 Greenhouse gas pollutants and greenhouse gases means compounds regulated under 

this part based primarily on their impact on the climate. This includes CO2, CH4, and 

N2O. 

 Gross vehicle weight rating (GVWR) means the value specified by the vehicle 

manufacturer as the maximum design loaded weight of a single vehicle, consistent with 

good engineering judgment. 

 Heavy-duty engine means any engine which the engine manufacturer could 

reasonably expect to be used for motive power in a heavy-duty vehicle. For purposes of 

this definition in this part, the term “engine” includes internal combustion engines and 

other devices that convert chemical fuel into motive power. For example, a fuel cell used 
in a heavy-duty vehicle is a heavy-duty engine.

 Heavy-duty vehicle means any motor vehicle above 8,500 pounds GVWR or that has 

a vehicle curb weight above 6,000 pounds or that has a basic vehicle frontal area greater 

than 45 square feet. Curb weight has the meaning given in 40 CFR 86.1803-01, 

consistent with the provisions of 40 CFR 1037.140. Basic vehicle frontal area has the 

meaning given in 40 CFR 86.1803-01. 

 Hybrid engine or hybrid powertrain means an engine or powertrain that includes 

energy storage features other than a conventional battery system or conventional 

flywheel. Supplemental electrical batteries and hydraulic accumulators are examples of 

hybrid energy storage systems. Note that certain provisions in this part treat hybrid 

engines and powertrains intended for vehicles that include regenerative braking different 

than those intended for vehicles that do not include regenerative braking. 

 Hydrocarbon (HC) means the hydrocarbon group on which the emission standards are 

based for each fuel type. For alcohol-fueled engines, HC means nonmethane 

hydrocarbon equivalent (NMHCE). For all other engines, HC means nonmethane 

hydrocarbon (NMHC). 

 Identification number means a unique specification (for example, a model 

number/serial number combination) that allows someone to distinguish a particular 

engine from other similar engines. 

 Incomplete vehicle means a vehicle meeting the definition of incomplete vehicle in 

40 CFR 1037.801 when it is first sold as a vehicle. 

 Innovative technology means technology certified under §1036.610.

 Liquefied petroleum gas (LPG) means a liquid hydrocarbon fuel that is stored under 

pressure and is composed primarily of nonmethane compounds that are gases at

atmospheric conditions. 

 Low-hour means relating to an engine that has stabilized emissions and represents the 

undeteriorated emission level. This would generally involve less than 125 hours of 

operation. 

 Manufacture means the physical and engineering process of designing, constructing, 

and/or assembling a heavy-duty engine or a heavy-duty vehicle. 

 Manufacturer has the meaning given in section 216(1) of the Act. In general, this 

term includes any person who manufactures an engine, vehicle, or piece of equipment for 

sale in the United States or otherwise introduces a new engine into commerce in the 

United States. This includes importers who import engines or vehicles for resale. 

Medium-duty passenger vehicle has the meaning given in 40 CFR 86.1803-01. 

Model year means the manufacturer’s annual new model production period, except as

restricted under this definition. It must include January 1 of the calendar year for which 

the model year is named, may not begin before January 2 of the previous calendar year, 

and it must end by December 31 of the named calendar year. Manufacturers may not 

adjust model years to circumvent or delay compliance with emission standards or to 

avoid the obligation to certify annually. 

 Motor vehicle has the meaning given in 40 CFR 85.1703. 

 Natural gas means a fuel whose primary constituent is methane. 

 New motor vehicle engine means a motor vehicle engine meeting the criteria of either 

paragraph (1) or (2) of this definition. 

(1) A motor vehicle engine for which the ultimate purchaser has never received the 
equitable or legal title is a new motor vehicle engine. This kind of engine might 

commonly be thought of as "brand new" although a new motor vehicle engine may 

include previously used parts. Under this definition, the engine is new from the time 

it is produced until the ultimate purchaser receives the title or places it into service, 

whichever comes first. 

(2) An imported motor vehicle engine is a new motor vehicle engine if it was 

originally built on or after January 1, 1970. 

 Noncompliant engine means an engine that was originally covered by a certificate of 

conformity, but is not in the certified configuration or otherwise does not comply with the 

conditions of the certificate. 

 Nonconforming engine means an engine not covered by a certificate of conformity 

that would otherwise be subject to emission standards. 

 Nonmethane hydrocarbons (NMHC) means the sum of all hydrocarbon species 

except methane, as measured according to 40 CFR part 1065. 

 Official emission result means the measured emission rate for an emission-data 

engine on a given duty cycle before the application of any deterioration factor, but after 

the applicability of any required regeneration adjustment factors. 

 Owners manual means a document or collection of documents prepared by the engine

or vehicle manufacturer for the owner or operator to describe appropriate engine 

maintenance, applicable warranties, and any other information related to operating or 

keeping the engine. The owners manual is typically provided to the ultimate purchaser at 

the time of sale. 

 Oxides of nitrogen has the meaning given in 40 CFR 1065.1001. 

 Percent has the meaning given in 40 CFR 1065.1001. Note that this means 

percentages identified in this part are assumed to be infinitely precise without regard to 

the number of significant figures. For example, one percent of 1,493 is 14.93. 

Petroleum means gasoline or diesel fuel or other fuels normally derived from crude 

oil. This does not include methane or LPG. 

 Placed into service means put into initial use for its intended purpose. 

Primary intended service class has the meaning given in § 1036.140. 

 Rated power has the meaning given in 40 CFR part 86. 

 Rechargeable Energy Storage System (RESS) means the component(s) of a hybrid 

engine or vehicle that store recovered energy for later use, such as the battery system in 

an electric hybrid vehicle.

 Revoke has the meaning given in 40 CFR 1068.30. 

 Round has the meaning given in 40 CFR 1065.1001. 

 Scheduled maintenance means adjusting, repairing, removing, disassembling, 

cleaning, or replacing components or systems periodically to keep a part or system from 

failing, malfunctioning, or wearing prematurely. It also may mean actions you expect are 

necessary to correct an overt indication of failure or malfunction for which periodic 

maintenance is not appropriate. 

 Small manufacturer means a manufacturer meeting the criteria specified in 13 CFR 

121.201. For manufacturers owned by a parent company, the production limit applies to 

the production of the parent company and all its subsidiaries and the employee limit 

appliesand revenue limits apply to the total number of employees and total revenue of the 

parent company and all its subsidiaries. 
 Spark-ignition means relating to a gasoline-fueled engine or any other type of engine 

with a spark plug (or other sparking device) and with operating characteristics 

significantly similar to the theoretical Otto combustion cycle. Spark-ignition engines 

usually use a throttle to regulate intake air flow to control power during normal operation. 

 Steady-state has the meaning given in 40 CFR 1065.1001. 

 Suspend has the meaning given in 40 CFR 1068.30. 

 Test engine means an engine in a test sample. 

 Test sample means the collection of engines selected from the population of an 

engine family for emission testing. This may include testing for certification, productionline testing, or in-use testing. 

 Tractor means a vehicle meeting the definition of “tractor” in 40 CFR 1037.801, but 

not classified as a “vocational tractor” under 40 CFR 1037.630, or relating to such a 

vehicle. 

 Tractor engine means an engine certified for use in tractors. Where an engine family 

is certified for use in both tractors and vocational vehicles, “tractor engine” means an 

engine that the engine manufacturer reasonably believes will be (or has been) installed in 

a tractor. Note that the provisions of this part may require a manufacturer to document 

how it determines that an engine is a tractor engine. 

 Ultimate purchaser means, with respect to any new engine or vehicle, the first person 

who in good faith purchases such new engine or vehicle for purposes other than resale. 

 United States has the meaning given in 40 CFR 1068.30. 

 Upcoming model year means for an engine family the model year after the one 

currently in production. 

 U.S.-directed production volume means the number of engine unitsengines, subject to 

the requirements of this part, produced by a manufacturer for which the manufacturer has 

a reasonable assurance that sale was or will be made to ultimate purchasers in the United 

States. This does not include engines certified to state emission standards that are 

different than the emission standards in this part. 

 Vehicle has the meaning given in 40 CFR 1037.801. 

 Vocational engine means an engine certified for use in vocational vehicles. Where an 

engine family is certified for use in both tractors and vocational vehicles, “vocational 

engine” means an engine that the engine manufacturer reasonably believes will be (or has 

been) installed in a vocational vehicle. Note that the provisions of this part may require a 

manufacturer to document how it determines that an engine is a vocational engine. 

 Vocational vehicle means a vehicle meeting the definition of “vocational” vehicle in 

40 CFR 1037.801. 

 Void has the meaning given in 40 CFR 1068.30. 

 We (us, our) means the Administrator of the Environmental Protection Agency and 

any authorized representatives. 

§ 1036.805 Symbols, acronyms, and abbreviations.

 The following symbols, acronyms, and abbreviations apply to this part: 

ABT averaging, banking, and trading.

AECD auxiliary emission control device. 

ASTM American Society for Testing and Materials. 

BTU British thermal units. 

CFR Code of Federal Regulations. 
CH4

 methane. 

CO carbon monoxide. 

CO2 carbon dioxide. 

DF deterioration factor.

DOT Department of Transportation. 

E85 gasoline blend including nominally 85 percent ethanol.

EPA Environmental Protection Agency. 

FCL Family Certification Level. 

FEL Family Emission Limit. 

g/hp-hr grams per brake horsepower-hour. 

GVWR gross vehicle weight rating. 

HC hydrocarbon. 

kg kilogram.

kgC kilogram carbon.

kW kilowatts.

lb pound.

lbC pound carbon.

LPG liquefied petroleum gas. 

Mg megagrams (106

 grams, or one metric ton). 

MJ megajoules.

N2O nitrous oxide. 

NARA National Archives and Records Administration. 

NHTSA National Highway Traffic Safety Administration. 

NMHC nonmethane hydrocarbons.

NOx oxides of nitrogen (NO and NO2). 

NTE not-to-exceed.

PM particulate matter. 

RESS rechargeable energy storage system.

RPM revolutions per minute. 

SET Supplemental Emission Test (see 40 CFR 86.1362-2010). 

THCU.S. total hydrocarbon.United States.

THCE total hydrocarbon equivalent.

U.S.C. United States Code. 

§ 1036.810 Incorporation by reference. 

(a) Certain material is incorporated by reference into this part with the approval of the 

Director of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51.(a) Certain 

material is incorporated by reference into this part with the approval of the Director of the 

Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. To enforce any edition other 

than that specified in this section, the Environmental Protection Agency must publish a 

notice of the change in the Federal Register and the material must be available to the 

public. All approved material is available for inspection at U.S. EPA, Air and Radiation 

Docket and Information Center, 1301 Constitution Ave., NW., Room B102, EPA West 

Building, Washington, DC 20460, (202) 202-1744, and is available from the sources 

listed below. It is also available for inspection at the National Archives and Records 

Administration (NARA). For information on the availability of this material at NARA, 

call 202–741–6030, or go to:

http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html

and is available from the sources listed below:.
(b) American Society for Testing and Materials, 100 Barr Harbor Drive, P.O. Box C700, 

West Conshohocken, PA, 19428-2959, (610) 832-9585, http://www.astm.org/.

(1) ASTM D4809-09a, xxx, IBRD 240–09 Standard Test Method for Heat of 

Combustion of Liquid Hydrocarbon Fuels by Bomb Calorimeter, approved July 1, 

2009, IBR approved for § 1036.530(b). 

(2) ASTM D4809-09a Standard Test Method for Heat of Combustion of Liquid 

Hydrocarbon Fuels by Bomb Calorimeter (Precision Method), approved September 1, 

2009, IBR approved for § 1036.530(b).

(3) ASTM D5291-02, xxx10 Standard Test Methods for Instrumental Determination 

of Carbon, Hydrogen, and Nitrogen in Petroleum Products and Lubricants, approved 

May 1, 2010, IBR approved for § 1036.530(b). 

§ 1036.815 What provisions apply to confidential information? 

The provisions of 40 CFR 1068.10 apply for information you consider confidential. 

§ 1036.820 Requesting a hearing. 

(a) You may request a hearing under certain circumstances, as described elsewhere in this 

part. To do this, you must file a written request, including a description of your objection 

and any supporting data, within 30 days after we make a decision. 

(b) For a hearing you request under the provisions of this part, we will approve your 

request if we find that your request raises a substantial factual issue. 

(c) If we agree to hold a hearing, we will use the procedures specified in 40 CFR part 

1068, subpart G. 

§ 1036.825 Reporting and recordkeeping requirements. 

(a) This part includes various requirements to submit and record data or other 

information. Unless we specify otherwise, store required records in any format and on 

any media and keep them readily available for eight years after you send an associated 

application for certification, or eight years after you generate the data if they do not 

support an application for certification. You may not rely on anyone else to meet

recordkeeping requirements on your behalf unless we specifically authorize it. We may 

review these records at any time. You must promptly send us organized, written records 

in English if we ask for them. We may require you to submit written records in an 

electronic format. 

(b) The regulations in § 1036.255, 40 CFR 1068.25, and 40 CFR 1068.101 describe your 

obligation to report truthful and complete information. This includes information not 

related to certification. Failing to properly report information and keep the records we 

specify violates 40 CFR 1068.101(a)(2), which may involve civil or criminal penalties. 

(c) Send all reports and requests for approval to the Designated Compliance Officer (see 

§ 1036.801). 

(d) Any written information we require you to send to or receive from another company 

is deemed to be a required record under this section. Such records are also deemed to be 

submissions to EPA. Keep these records for eight years unless the regulations specify a 

different period. We may require you to send us these records whether or not you are a 

certificate holder. 

(e) Under the Paperwork Reduction Act (44 U.S.C. 3501 et seq.), the Office of 
Management and Budget approves the reporting and recordkeeping specified in the 

applicable regulations. The following items illustrate the kind of reporting and 

recordkeeping we require for engines and equipment regulated under this part: 

(1) We specify the following requirements related to engine certification in this part 

1036: 

(i) In § 1036.135 we require engine manufacturers to keep certain records related 

to duplicate labels sent to equipment manufacturers. 

(ii) In subpart C of this part we identify a wide range of information required to 

certify engines. 

(iii) [Reserved]In subpart G of this part we identify several reporting and 

recordkeeping items for making demonstrations and getting approval related to 

various special compliance provisions. 

(iv) In § 1036.725, 1036.730, and 1036.735 we specify certain records related to 

averaging, banking, and trading. 

(2) We specify the following requirements related to testing in 40 CFR part 1066: 

(i) In 40 CFR 1066.2 we give an overview of principles for reporting 

information.(i) In 40 CFR 1066.2 we give an overview of principles for reporting 

information.

(ii) [Reserved] 

A new part 1037 is added to subchapter U to read as follows: 

PART 1037—CONTROL OF EMISSIONS FROM NEW HEAVY-DUTY MOTOR 

VEHICLES 

Subpart A—Overview and Applicability 

Sec. 

1037.1 Applicability 

1037.5 Excluded vehicles. 

1037.10 How is this part organized? 

1037.15 Do any other regulation parts apply to me? 

1037.30 Submission of information. 

Subpart B—Emission Standards and Related Requirements 

1037.101 Overview of emission standards for heavy-duty vehicles. 

1037.102 Exhaust emission standards for NOx, HC, PM, and CO. 

1037.103 Evaporative emission standards.

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

or below 14,000 pounds GVWR. 

1037.105 Exhaust emission standards for CO2, CH4, and N2O for vocational vehicles. 

1037.106 Exhaust emission standards for CO2, CH4, and N2O for tractors above 26,000 

pounds GVWR. 

1037.115 Other requirements. 

1037.120 Emission-related warranty requirements. 

1037.125 Maintenance instructions and allowable maintenance. 
1037.135 Labeling. 

1037.140 Curb weight and roof height. 

1037.141 Determining aerodynamic bins for tractors.

1037.150 Interim provisions. 

Subpart C—Certifying Vehicle families 

1037.201 General requirements for obtaining a certificate of conformity. 

1037.205 What must I include in my application? 

1037.210 Preliminary approval before certification. 

1037.220 Amending maintenance instructions. 

1037.225 Amending applications for certification. 

1037.230 Vehicle families, sub-families, and configurations. 

1037.241 Demonstrating compliance with exhaust emission standards for greenhouse

gas pollutants. 

1037.243 Demonstrating compliance with evaporative emission standards.

1037.250 Reporting and recordkeeping. 

1037.255 What decisions may EPA make regarding my certificate of conformity? 

Subpart D—[Reserved] 

Subpart E—In-use Testing 

1037.401 General provisions. 

Subpart F—Test and Modeling Procedures 

1037.501 General testing and modeling provisions. 

1037.510 Duty-cycle testing. 

1037.520 Modeling CO2 emissions to show compliance. 

1037.521 Aerodynamic measurements.

1037.525 Special procedures for testing hybrid vehicles with power take-off. 

1037.550 Special procedures for testing post-transmission hybrid systems. 

Subpart G—Special Compliance Provisions 

1037.601 What compliance provisions apply to these vehicles? 

1037.610 Hybrid vehicles and other advancedVehicles with innovative technologies. 

1037.611 Vehicles with innovative615 Hybrid vehicles and other advanced

technologies. 

1037.620 Shipment of incomplete vehicles to secondary vehicle manufacturers. 

1037.630 Special purpose tractors.

1037.631 Exemption for vocational vehicles intended for offroad use. 

1037.640 Variable vehicle speed limiters. 

1037.645 In-use compliance with family emission limits (FELs).

1037.650 Tire manufacturers.
1037.655 Post-useful life vehicle modifications.

1037.660 Automatic engine shutdown systems.

Subpart H—Averaging, Banking, and Trading for Certification 

1037.701 General provisions. 

1037.705 Generating and calculating emission credits. 

1037.710 Averaging. 

1037.715 Banking. 

1037.720 Trading. 

1037.725 What must I include in my application for certification? 

1037.730 ABT reports. 

1037.735 Recordkeeping. 

1037.740 What restrictions applyRestrictions for using emission credits?.

1037.745 End-of-year CO2 credit deficits. 

1037.750 What can happen if I do not comply with the provisions of this subpart? 

1037.755 Information provided to the Department of Transportation. 

Subpart I—Definitions and Other Reference Information 

1037.801 Definitions. 

1037.805 Symbols, acronyms, and abbreviations. 

1037.810 Incorporation by reference. 

1037.815 What provisions apply to confidential information? 

1037.820 Requesting a hearing. 

1037.825 Reporting and recordkeeping requirements. 

Appendix I to part 1037 — Heavy-duty Transient Chassis Test Cycle 

Appendix II to part 1037 — Power Take-Off Test Cycle 

Appendix III to part 1037 —Emission Control Identifiers

Authority: 42 U.S.C. 7401 - 7671q. 

Subpart A—Overview and Applicability 

§ 1037.1 Applicability 

This part contains standards and other regulations applicable to the emission of the air 

pollutant defined as the aggregate group of six greenhouse gases: carbon dioxide, nitrous

oxide, methane, hydrofluorocarbons, perflurocarbons, and sulfur hexafluoride. The 

regulations in this part 1037 apply for all new heavy-duty vehicles, except as provided in 

§1037.5. This includes electric vehicles and vehicles fueled by conventional and 

alternative fuels. 

§ 1037.5 Excluded vehicles. 

Except for the definitions specified in §1037.801, this part does not apply to the

following vehicles: 
(a) Vehicles not meeting the definition of “motor vehicle”.

(b) Vehicles excluded from the definition of “heavy-duty vehicle” in §1037.801 because 

of vehicle weight or, weight rating, and frontal area (such as light-duty vehicles and lightduty trucks). 

(bc) Medium-duty passenger vehicles. 

(cd) Vehicles produced in model years before 2014, unless they are certified under 

§ 1037.150. 

(d) Vehicles not meeting the definition of “motor vehicle”. e) Vehicles subject to the 

light-duty greenhouse gas standards of 40 CFR part 86. See 40 CFR 86.1818 for 

greenhouse gas standards that apply for these vehicles. An example of such a vehicle 

would be a vehicle meeting the definition of “heavy-duty vehicle” in §1037.801 and 40 

CFR 86.1803, but also meeting the definition of “light truck” in 40 CFR 86.1818-

12(b)(2).

§ 1037.10 How is this part organized? 

This part 1037 is divided into subparts as described in this section. Note that only 

subparts A, B, and I of this part apply for vehicles subject to the standards of § 1037.104, 

as described in that section. 

(a) Subpart A of this part defines the applicability of part 1037 and gives an overview of 

regulatory requirements. 

(b) Subpart B of this part describes the emission standards and other requirements that 

must be met to certify vehicles under this part. Note that § 1037.150 discusses certain 

interim requirements and compliance provisions that apply only for a limited time. 

(c) Subpart C of this part describes how to apply for a certificate of conformity for 

vehicles subject to the standards of § 1037.105 or § 1037.106. 

(d) [Reserved] 

(e) [Reserved]

(e) Subpart E of this part addresses testing of in-use vehicles.

(f) Subpart F of this part describes how to test your vehicles and perform emission 

modeling (including references to other parts of the Code of Federal Regulations) for 

vehicles subject to the standards of § 1037.105 or § 1037.106. 

(g) Subpart G of this part and 40 CFR part 1068 describe requirements, prohibitions, and 

other provisions that apply to manufacturers, owners, operators, rebuilders, and all others. 

See §Section 1037.601 for a specification ofdescribes how 40 CFR part 1068 applies for 

heavy-duty vehicles. 

(h) Subpart H of this part describes how you may generate and use emission credits to 

certify your vehicles for vehiclesthat are subject to the standards of § 1037.105 or 

§ 1037.106. 

(i) Subpart I of this part contains definitions and other reference information. 

§ 1037.15 Do any other regulation parts apply to me? 

(a) Parts 1065 and 1066 of this chapter describe procedures and equipment specifications 

for testing engines and vehicles to measure exhaust emissions. Subpart F of this part 

1037 describes how to apply the provisions of part 1065 and part 1066 of this chapter to 

determine whether vehicles meet the exhaust emission standards in this part. 

(b) As described in § 1037.601, certain requirements and prohibitions of part 1068 of this 
chapter apply to everyone, including anyone who manufactures, imports, installs, owns, 

operates, or rebuilds any of the vehicles subject to this part 1037. Part 1068 of this 

chapter describes general provisions, including that apply broadly, but do not necessarily 

apply for all vehicles or all persons. The issues addressed by these provisions include

these seven areas: 

 (1) Prohibited acts and penalties for manufacturers and others. 

 (2) Rebuilding and other aftermarket changes. 

 (3) Exclusions and exemptions for certain vehicles. 

(4) Importing vehicles. 

 (5) Selective enforcement audits of your production. 

 (6) Recall. 

 (7) Procedures for hearings. 

(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 of part 86, applies for 

vehicles subject to § 1037.104. 

(d) Other parts of this chapter apply if referenced in this part. 

§ 1037.30 Submission of information. 

Send all reports and requests for approval to the Designated Compliance Officer (see 

§ 1037.801). See § 1037.825 for additional reporting and recordkeeping provisions. 

Subpart B—Emission Standards and Related Requirements 

§ 1037.101 Overview of emission standards for heavy-duty vehicles. 

(a) This part specifies emission standards for certain vehicles and for certain pollutants. 

It also summarizes other standards that apply under 40 CFR part 86. This part contains 

standards and other regulations applicable to the emission of the air pollutant defined as 

the aggregate group of six greenhouse gases: carbon dioxide, nitrous oxide, methane, 

hydrofluorocarbons, perflurocarbons, and sulfur hexafluoride. 

(b) The regulated emissions are addressed in threefour groups: 

(1) Exhaust emissions of NOx, HC, PM, and CO. These pollutants are sometimes

described collectively as “criteria pollutants” because they are either criteria 

pollutants under the Clean Air Act or precursors to the criteria pollutant ozone. These 

pollutants are also sometimes described collectively as “non-greenhouse gas 

pollutants”, although they do not necessarily have negligible global warming 

potentials. As described in § 1037.102, standards for these pollutants are provided in 

40 CFR part 86. 

(2) Exhaust emissions of CO2, CH4, and N2O. These pollutants are described 

collectively in this part as “greenhouse gas pollutants” because they are regulated 

primarily based on their impact on the climate. These standards are provided in 

§§ 1037.104 through 1037.106. 

(3(3) Hydrofluorocarbons. These pollutants are also “greenhouse gas pollutants” but 

are treated separately from exhaust greenhouse gas pollutants listed in paragraph 

(b)(2) of this section. These standards are provided in § 1037.115.

(4) Fuel evaporative emissions. These requirements are described in § 1037.10340 

CFR part 86. 
(c) The regulated heavy-duty vehicles are addressed in different groups as follows: 

(1) For criteria pollutants, vehicles are regulated based on gross vehicle weight rating 

(GVWR), whether they are considered “spark-ignition” or “compression-ignition,” 

and whether they are first sold as complete or incomplete vehicles. These groupings 

apply as described in 40 CFR part 86. 

(2) For greenhouse gas pollutants, vehicles are regulated in the following groups: 

(i) Complete and certain incomplete vehicles at or below 14,000 pounds GVWR 

(see § 1037.104 for further specification). Certain provisions of 40 CFR part 86 

apply for these vehicles; see § 1037.104(ih) for a list of provisions in this part 

1037 that also apply for these vehicles. These provisions may also be optionally 

applied to certain other vehicles, as described in §1037.104. 

(ii) Tractors above 26,000 pounds GVWR. 

(iii) All other vehicles subject to standards under this part. These other vehicles 

are referred to as “vocational” vehicles. 

(3) For evaporative emissions, vehicles are regulated based on the type of fuel they 

use. Vehicles fueled with volatile liquid fuels and gaseous fuels are subject to 

evaporative emission standards, while other vehicles are not.

§ 1037.102 Exhaust emission standards for NOx, HC, PM, and CO. 

See 40 CFR part 86 for the exhaust emission standards for NOx, HC, PM, and CO that 

apply for heavy-duty vehicles. 

§ 1037.103 Evaporative emission standards.

New vehicles that run on volatile liquid fuel (such as gasoline or ethanol) or gaseous fuel 

(such as natural gas or LPG) must meet evaporative emission standards as specified in 

this section. The standards specified in paragraphs (a) and (b) of this section apply over a 

useful life period of 10 years or 110,000 miles, whichever comes first. Note that this 

section and § 1037.243 allow you to certify without testing in certain circumstances. 

Evaporative emission standards do not apply for diesel-fueled vehicles. Note that 

vehicles subject to the evaporative emission requirements of this part are not subject to 

the evaporative emission requirements of 40 CFR part 86.

(a) Diurnal and hot soak emissions. Evaporative hydrocarbon emissions may not exceed 

the following standards when measured using the test procedures specified in § 1037.501:

(1) The sum of diurnal and hot soak measurements from the full three-day diurnal test 

sequence described in 40 CFR 86.1230-96 may not exceed 1.4 g for vehicles with 

GVWR at or below 14,000 pounds, and may not exceed 1.9 g for vehicles with 

GVWR above 14,000 pounds. 

(2) The sum of diurnal and hot soak measurements from the two-day diurnal test 

sequence described in 40 CFR 86.1230-96 may not exceed 1.75 g for vehicles with 

GVWR at or below 14,000 pounds, and may not exceed 2.3 g for vehicles with 

GVWR above 14,000 pounds. The standards in this paragraph (a)(2) do not apply for 

vehicles that run on natural gas or LPG.

(b) Running loss. Running losses may not exceed 0.05 g/mile when measured using the 

test procedures specified in § 1037.501. The running loss standard does not apply for 

vehicles that run on natural gas or LPG.

(c) Fuel spitback. Fuel spitback emissions from vehicles with GVWR at or below 14,000 
pounds may not exceed 1.0 g when measured using the test procedures specified in 

§ 1037.501. This standard does not apply for vehicles with GVWR above 14,000 pounds 

or any vehicles that run on natural gas or LPG. The fuel spitback standard applies only to 

newly assembled vehicles. 

(d) Refueling emissions. Complete vehicles with GVWR at or below 10,000 pounds must 

meet refueling emission standards as specified in 40 CFR part 86, subpart S. This 

includes the refueling receptacle requirements in 40 CFR 86.1810-01(k)(3) for vehicles 

that run on natural gas. Incomplete heavy-duty vehicles are not subject to refueling 

emission standards.

(e) Compliance demonstration for vehicles with GVWR above 26,000 pounds. For 

vehicles with GVWR above 26,000 pounds, the standards described in paragraphs (a) and 

(b) of this section are based on an engineering analysis showing that the vehicle design 

adequately controls emissions. We would expect emission control components and 

systems to exhibit a comparable degree of control relative to vehicles that comply based 

on testing. For example, vehicles that comply under this paragraph (e) should rely on 

comparable material specifications to limit fuel permeation, and components should be 

sized and calibrated to correspond with the appropriate fuel capacities, fuel flow rates, 

and vehicle operating characteristics.

(f) Incomplete vehicles. If you sell incomplete vehicles, you must identify the maximum

fuel tank capacity for which you designed the vehicle’s evaporative emission control

system. 

(g) Auxiliary engines and separate fuel systems. The provisions of this paragraph (g) 

apply for vehicles with auxiliary engines. This includes any engines installed in the final 

vehicle configuration that contribute no motive power through the vehicle’s transmission. 

(1) Auxiliary engines and associated fuel-system components must be installed when 

testing complete vehicles. If the auxiliary engine draws fuel from a separate fuel 

tank, you must fill the extra fuel tank before the start of diurnal testing as described 

for the vehicle’s main fuel tank. Use good engineering judgment to ensure that any 

nonmetal portions of the fuel system related to the auxiliary engine have reached 

stabilized levels of permeation emissions. The auxiliary engine must not operate 

during the running loss test or any other portion of testing under this section.

(2) For testing with incomplete vehicles, you may omit installation of auxiliary 

engines and associated fuel-system components as long as those components installed 

in the final configuration are certified to meet the applicable emission standards for 

Small SI equipment described in 40 CFR 1054.112 or for Large SI engines in 40 CFR 

1048.105. (Note: We do not consider installation of aftermarket engines into nonnew motor vehicles to be tampering if the installer complies with the requirements of 

this paragraph (g)(2).) For any fuel-system components that you do not install, your 

installation instructions must describe this certification requirement. 

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

vehicles at or below 14,000 pounds GVWR. 

This section applies for heavy-duty vehicles at or below 14,000 pounds GVWR. See 

paragraphs (f) and (g)§1037.150 of this section for provisions excluding certain vehicles 

from this section, and allowing other vehicles to be certified under this section. 
(a) Fleet-average CO2 emission standards. Fleet-average CO2 emission standards apply 

for each manufacturer as follows: 

(1) First Calculate a work factor, WF, for each vehicle configurationsubconfiguration

(or group of subconfigurations allowed under paragraph (a)(4) of this section),

rounded to the nearest pound, using the following equation: 

WF = 0.75× (GVWR - Curb Weight + xwd) + 0.25 × (GCWR – GVWR) 

Where: 

xwd = 500 pounds if the vehicle has four-wheel drive or all-wheel drive; xwd = 0 

pounds for all other vehicles. 

(2) Using the appropriate work factor, calculate a target value for each vehicle 

subconfiguration (or submodel groups group of configurations we 

approvesubconfigurations allowed under paragraph (a)(4) of this section) you 

produce using one of the applicable equation of this paragraph (a)(2),following 

equations, rounding the target value to the nearest 0.1 g/mile.:

(i) For spark-ignition vehicles: CO2 Target (g/mile) = 0.0440 × WF + 339 

(ii) For compression-ignition vehicles and vehicles that operate without engines 

(such as electric vehicles and fuel cell vehicles): CO2 Target (g/mile) = 0.0416 × 

WF + 320 

(3) Calculate a production-weighted average of the target values and round it to the 

nearest 0.1 g/mile. This is your fleet-average standard. All vehicles subject to the 

standards of this section form a single averaging set. Use the following equation to 

calculate your fleet-average standard from the target value for each vehicle 

configuration or submodelsubconfiguration (Targeti) and U.S.-directed production 

volume of each vehicle configuration or submodelsubconfiguration for the given 

model year (Volumei): 

[ ]

[ ]

Target Volume

Fleet-Average Standard

Volume

i i

i

×

= ∑

∑

(4) You may group subconfigurations within a configuration together for purposes of 

calculating your fleet-average standard as follows:

(i) You may group together subconfigurations that have the same equivalent test 

weight (ETW), GVWR, and GCWR. Calculate your work factor and target value 

assuming a curb weight equal to two times ETW minus GVWR. 

(ii) You may group together other subconfigurations if you use the lowest target 

value calculated for any of the subconfigurations.

(b) Production and in-use CO2 standards. Each vehicle you produce that is subject to the 

standards of this section has an “in-use” CO2 standard that is calculated from your test 

result and that applies for SEA testingselective enforcement audits and in-use testing. 

TheThis in-use CO2 standard for each vehicle is equal to the applicable deteriorated 

emission level applicable for that vehicle multiplied by 1.10 and rounded to the nearest 

0.1 g/mile. 

(c) N2O and CH4 standards. Except as allowed under this paragraph (c), all vehicles 

subject to the standards of this section must comply with an N2O standard of 0.05 g/mile 

and a CH4 standard of 0.05 g/mile. You may specify CH4 and/or N2O FELs and 

usealternate standards using CO2 emission credits to show compliance with those FELs 

instead of these otherwise applicable emission standards for one or more test groups, 

consistent with the provisions of 40 CFR 86.1818. To do this, calculate the CH4 and/or 

Field Code Changed
N2O emission credits needed (negative credits) using the equation in this paragraph (c) 

based on the FEL(s) you specify for your vehicles during certification. You must adjust 

the calculated emissions by the relative global warming potential (RGWP): 

RGWPGWP): GWP equals 25 for CH4 and 298 for N2O. This means you must use 25 

Mg of positive CO2 credits to offset 1 Mg of negative CH4 credits and 298 Mg of positive 

CO2 credits to offset 1 Mg of negative N2O credits. Note that 40 CFR 86.1818-12(f)(2) 

does not apply for vehicles subject to the standards of this section. Calculate credits 

using the following equation: 

CO2 Credits Needed (Mg) = [(FEL - Std - FEL) × (U.S.-directed production volume) × 

(Useful Life)] × (RGWP) ÷ 1,000,000 

(d) Compliance provisions. Except as specified in this paragraph (d) or elsewhere in this 

section, the provisions of 40 CFR part 86, describing compliance with the greenhouse gas 

standards of 40 CFR part 86, subpart S of that part, apply with respect to the standards of 

paragraphs (a) through (c) of this section. 

(1) The CO2 standards of this section apply with respect to CO2 emissions instead of,

not with respect to carbon-related exhaust emissions (CREE). 

(2) Vehicles subject to the standards of this section are included in a single 

greenhouse gas averaging set separate from any averaging sets otherwise included in 

40 CFR part 86. 

(3) Special credit and incentive provisions related to flexible -fuel vehicles and air 

conditioning in 40 CFR part 86 do not apply for vehicles subject to the standards of 

this section. 

(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. 

(5) Apply an additive deterioration factor of zero to measured CO2 emissions unless 

good engineering judgment indicates that emissions are likely to deteriorate in actual 

use. Use good engineering judgment to develop separate deterioration factors for N2O 

and CH4. 

(6) Credits are calculated using the useful life value (in miles) in place of the “vehicle 

lifetime miles” specified in subpart S of 40 CFR part 86, subpart S. 

(7) Credits generated from hybrid vehicles with regenerative braking or from vehicles 

(§§1037.610 and 1037.611) with other advanced technologies may be used to show 

compliance with any standards of this part or 40 CFR part 1036, provided they are 

converted using good engineering judgment subject to be equivalent to the service 

class restrictions in §1037.740. Include these vehicles in a separate fleet-average 

calculation (and exclude them from your conventional fleet-average calculation). 

You must first apply these advanced technology vehicle credits calculated under that 

partto any deficits for other vehicles in the averaging set before applying them to 

other averaging sets. 

(8) The provisions of 40 CFR 86.1818 do not apply. 

(9) Calculate your fleet-average emission rate consistent with good engineering 

judgment and the provisions of 40 CFR 86.1865. The following additional provisions 

apply:

(i) Unless we approve a lower number, you must test at least ten 
subconfigurations. If you produce more than 100 subconfigurations in a given 

model year, you must test at least ten percent of your subconfigurations. For 

purposes of this paragraph (9)(i), count carryover tests, but do not include 

analytically derived CO2 emission rates, data substitutions, or other untested 

allowances. We may approve a lower number of tests for manufacturers that have 

limited product offerings, or low sales volumes. Note that good engineering 

judgment and other provisions of this part may require you to test more 

subconfigurations than these minimum values.

(ii) The provisions of paragraph (g) of this section specify how you may use 

analytically derived CO2 emission rates.

(iii) At least 90 percent of final production volume at the configuration level must 

be represented by test data (real, data substituted, or analytical).

(10) For dual fuel, multi-fuel, and flex-ible fuel vehicles, perform exhaust testing on 

each fuel type (for example, gasoline and E85). 

(i) For your fleet-average calculations, use a either the conventional-fueled CO2

emission rate or a weighted average of your emission results as specified in 40 

CFR part 86600.510–12(k) for light-duty trucks. 

(ii) If you certify to an FELalternate standard for N2O or CH4 emissions, you may 

not exceed the FELalternate standard when tested on either fuel. 

(1011) Test your vehicles with a an equivalent test weight equal tobased on its

Adjusted Loaded Vehicle Weight (i.e., ALVW). Determine equivalent test weight 

from the numerical average ofALVW as specified in 40 CFR 86.129, except that you

may round values to the nearest 500 pound increment for ALVW above 14,000 

pounds).

(12) The following definitions apply for 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. Note that this differs from the definition in 40 

CFR 86.1803 because it excludes inertia weight class as a criterion.

(ii) Subconfiguration means a unique combination within a vehicle curb weight 

and GVWR), 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.

(iii) The terms “complete vehicle” and “incomplete vehicle” have the meanings 

given for “complete heavy-duty vehicle” and “incomplete heavy-duty vehicle” in 

40 CFR 86.1803.

(13) This paragraph (d)(13) applies for CO2 reductions resulting from technologies 

that were not in common use before 2010 that are not reflected in the specified test 

procedures. We may allow you to generate emission credits consistent with the 

provisions of 40 CFR 86.1866-12(d). You do not need to provide justification for not 

using the 5-cycle methodology option.

(14) You must submit pre-model year reports before you submit your applications for 

certification for a given model year. Unless we specify otherwise, include the 

information specified for pre-model year reports in 49 CFR 535.8.

(e) Useful life. Your vehicles must meet the exhaust emission standards of this section 
throughout their full useful life, expressed in service miles or calendar years, whichever 

comes first. The useful life values for the standards of this section are those that apply 

for criteria pollutants under 40 CFR part 86. 

(f) Incomplete vehicle exclusion. Exclusion of vehicles not certified as complete 

vehicles. The standards of this section apply for each vehicle that is chassis-certified 

with respect to criteria pollutants. The standards of this section do not apply for other 

vehicles, except as allowed under paragraph (g) of this section.40 CFR part 86, subpart S. 

The standards of this section do not apply for other vehicles, except as noted in 

§1037.150. Note that vehicles excluded under this paragraph (f) are not considered to be 

“subject to the standards of this section.” The vehicle standards and requirements of 

§ 1037.105 apply for the excluded vehicles. The GHG standards of 40 CFR part 1036 

also apply for engines used in these excluded vehicles. If you are not the engine 

manufacturer, you must notify the engine manufacturers that theirits engines are subject 

to 40 CFR part 1036 because you intend to use their engines in your excluded vehicles. 

(g) Optional certification under this section. You may certify any vehicle at or below 

19,500 pounds GVWR to the standards of this section.

(1) You may certify complete and/or incomplete Class 4 and/or Class 5 vehicles to the 

standards of this section.

 

(2) You may apply the provisions of this section to incomplete vehicles in the same 

manner as they apply to complete vehicles, except as specified in this paragraph(g)(2). 

Calculate the target value based on the same work factor value that applies for the most 

similar complete vehicle you certify. Test these incomplete vehicles using the same test 

weight and other dynamometer settings that apply for the complete vehicle from which 

you used the work factor value. For certification, you may submit the test data from that 

similar vehicle instead of performing the test on the -incomplete vehicle. 

(g) Analytically derived CO2 emission rates (ADCs). This paragraph (g) describes an 

allowance to use estimated (i.e., analytically derived) CO2 emission rates based on 

baseline test data instead of measured emission rates for calculating fleet-average 

emissions. Note that these ADCs are similar to ADFEs used for light-duty vehicles. 

Note also that F terms used in this paragraph (g) represent coefficients from the following 

road load equation:

  	

		
  0  1 · 
  2 · 


(1) Except as specified in paragraph (g)(2) of this section, use the following equation 

to calculate the ADC of a new vehicle from road load force coefficients (F0, F1, F2), 

axle ratio, and test weight :

  2  2.18 · ∆0  37.4 · ∆1  2257 · ∆2  189 · ∆)  0.0222

· ∆*+,

Where:

ADC = Analytically derived combined city/highway CO2 emission rate (g/mile) for a 

new vehicle.

CO2base= Combined city/highway CO2 emission rate (g/mile) of a baseline vehicle.

∆F0 = F0 of the new vehicle – F0 of the baseline vehicle.

∆F1 = F1 of the new vehicle – F1 of the baseline vehicle.
∆F2 = F2 of the new vehicle – F2 of the baseline vehicle.

∆AR = Axle ratio of the new vehicle – axle ratio of the baseline vehicle.

∆ETW = ETW of the new vehicle – ETW of the baseline vehicle.

(2) The purpose of this section is to accurately estimate CO2 emission rates. You 

must apply the provisions of this section consistent with good engineering judgment. 

For example, do not use the equation in paragraph (g)(1) of this section where good 

engineering judgment indicates that it will not accurately estimate emissions. You 

may ask us to approve alternate equations that allow you to estimate emissions more 

accurately.

(3) You may select, without our prior approval, baseline test data that 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) Where necessary to minimize the CO2 adjustment, you may supplement 

the pool with tests associated with worst-case engine or transmission codes 

and carryover or carry-across engine families. If you do, all the data that 

qualify for inclusion using the elected worst-case substitution (or carryover or 

carry-across) must be included in the pool as supplemental data (i.e., 

individual test vehicles may not be selected for inclusion). You must also 

include the supplemental data in all subsequent pools, where applicable.

(iv) Tests previously used during the subject model year as baseline tests in 

ten other ADC subconfigurations must be eliminated from the pool. (v) Select 

the tested subconfiguration with the smallest absolute difference between the 

ADC and the test CO2 emission rate for combined emissions. Use this as the 

baseline test for the target ADC subconfiguration.

(4) You may ask us to allow you 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. The downward adjustment 

of ADC from the baseline is limited to ADC values 20 percent below the baseline 

emission rate (i.e., baseline emission rate × 0.80). The upward adjustment is not 

limited.

(6) You may not submit an ADC if an actual test has been run on the target

subconfiguration during the certification process or on a development vehicle that is

eligible to be declared as an emission-data vehicle.

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

submission may be represented by ADCs.

(8) You must retain for five years the pool of tests, the vehicle description and tests 

chosen as the baseline and the basis for its selection, the target ADC 

subconfiguration, and the calculated emission rates. We may ask to see these records 

at any time. 
(9) We may perform or order a confirmatory test of any subconfiguration covered by 

an ADC.

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

paragraph (g), we may rescind the use of ADC data, require generation of actual test 

data, and require recalculation of your fleet-average emission rate. 

(h) Applicability of part 1037 provisions. Except as specified in this section, the 

requirements of this part do not apply to vehicles certified to the standards of this section. 

The following provisions are the only provisions of this part that apply to vehicles 

certified under this section: 

(1) The provisions of this section. 

(2) The evaporative emission standards in § 1037.103.[Reserved]

(3) The air conditioning standards in § 1037.115. 

(4) The interim provisions of § 1037.150(a), (b), (c), (e) - (i), (l), and (e)-(hm). 

(5) The definitions of § 1037.801, to the extent such terms are used in this 

partrelative to vehicles subject to standards under this section. 

§ 1037.105 Exhaust emission standards for CO2, CH4, and N2O for vocational 

vehicles. 

(a) The standards of this section apply for the following vehicles: 

(1) Vehicles above 14,000 pounds GVWR butand at or below 26,000 pounds GVWR, 

but not certified to the vehicle standards §1037.104. 

(2) Vehicles above 26,000 pounds GVWR that are not tractors. 

(3) Vocational tractors.

(4) Vehicles at or below 14,000 pounds GVWR that are excluded from the standards 

in § 1037.104 under § 1037.104 (f) or use engines certified under §1037.150(m). 

(b) The CO2 standards of this section are given in Table 1 to this section. The provisions 

of § 1037.241 specify how to comply with these standards. 

Table 1 to § 1037.105—CO2 Standards for Vocational Vehicles 

GVWR 

(pounds) 

CO2 Standard (g/ton-mile) 

for 

Model Years 2014-2016 

CO2 Standard (g/ton-mile) 

for 

Model Year 2017 and later 

GVWR < 19,500 387388 373 

19,500 < GVWR < 33,000 234 225 

33,000 < GVWR 226 222 

(c) No CH4 or N2O standards apply under this section. See 40 CFR part 1036 for CH4 or 

N2O standards that apply to engines used in these vehicles. 

(d) You may generate or use emission credits under the ABT program, as described in 

subpart H of this part. This requires that you specify a Family Emission Limit (FEL) for 

each pollutant you include in the ABT programCO2 for each vehicle subfamily. The FEL 

may not be less than the result of emission modeling from § 1037.520. These FELs serve 

as the emission standards for the vehicle subfamily instead of the standards specified in 

paragraph (b) of this section. 

(e) TheYour vehicles must meet the exhaust emission standards of this section throughout 

their full useful life values for the , expressed in service miles or calendar years, 

whichever comes first. The following useful life values apply for the standards of this 
section: 

(1) 110,000 miles or 10 years, whichever comes first, for vehicles at or below 19,500 

pounds GVWR is 110.

(2) 185,000 miles or 10 years, whichever occurscomes first. The useful life values for 

the standards of this section, for vehicles above 19,500 pounds GVWR butand at or 

below 33,000 pounds GVWR is 185,000 miles or 10 years, whichever occurs first. 

The useful life value for the standards of this section for vehicles over 33,000 pounds 

GVWR is.

(3) 435,000 miles or 10 years, whichever occurs first. comes first, for vehicles above 

33,000 pounds GVWR.

(f) See § 1037.630631 for provisions that exempt certain vehicles used in offroadoff-road

operation from the standards of this section. 

(g) You may optionally certify a vocational vehicle to the standards and useful life 

applicable to a higher vehicle service class (such as medium heavy-duty instead of light 

heavy-duty), provided you do not generate credits with the vehicle. If you include 

smaller vehicles in a credit-generating subfamily (with an FEL below the standard), 

exclude its production volume from the credit calculation. 

§ 1037.106 Exhaust emission standards for CO2, CH4, and N2O for tractors above 

26,000 pounds GVWR. 

(a) The following CO2 standards CO2standards of this section apply for tractors above 

26,000 pounds GVWR:. Note that the standards of this section do not apply for vehicles 

classified as “vocational tractors” under §1037.630, 

(b) The CO2 standards for tractors above 26,000 pounds GVWR are given in Table 1 to 

this section. The provisions of § 1037.241 specify how to comply with these standards.

Table 1 to § 1037.106—CO2 Standards for Tractors above 26,000 Pounds GVWR 

GVWR 

(pounds) 

Sub-category CO2 Standard 

(g/ton-mile) for 

Model Years 

2014-2016 

CO2 Standard 

(g/ton-mile) for 

Model Year 

2017 and later 

26,000 < GVWR < 33,000

Low-Roof 

(all cab styles) 

107 104 

Mid-Roof 

(all cab styles) 

119 115 

High-Roof 

(all cab styles) 

122124 118120

GVWR > 33,000 

Low-Roof Day Cab 81 7980

Low-Roof Sleeper Cab 68 66 

Mid-Roof Day Cab 88 86 

Mid-Roof Sleeper Cab 7576 73 

High-Roof Day Cab 9092 8889

High-Roof Sleeper Cab 7375 7172

(bc) No CH4 or N2O standards apply under this section. See 40 CFR part 1036 for CH4

or N2O standards that apply to engines used in these vehicles. 

(cd) You may generate or use emission credits under the ABT program, as described in 
subpart H of this part. This requires that you specify a Family Emission Limit (FEL) for 

each pollutant you include in the ABT program for each vehicle subfamily. The FEL 

may not be less than the result of emission modeling from § 1037.520. These FELs serve 

as the emission standards for the specific vehicle subfamily instead of the standards 

specified in paragraph (a) of this section. 

(d) The useful life value for(e) Your vehicles must meet the exhaust emission standards 

of this section for vehicles at or below 33,000 pounds GVWR is 185,000throughout their 

full useful life, expressed in service miles or 10calendar years, whichever occurscomes

first. The following useful life valuevalues apply for the standards of this section: 

(1) 185,000 miles or 10 years, whichever comes first, for vehicles overat or below

33,000 pounds GVWR is.

(2) 435,000 miles or 10 years, whichever occurscomes first.

(e) See § 1037.630, for provisions that exempt certain vehicles use in offroad 

operation from the above 33,000 pounds GVWR.

(f) You may optionally certify a tractor to the standards and useful life applicable to a 

higher vehicle service class (such as heavy heavy-duty instead of this section.medium 

heavy-duty), provided you do not generate credits with the vehicle. If you include smaller 

vehicles in a credit-generating subfamily (with an FEL below the standard), exclude its 

production volume from the credit calculation. 

§ 1037.115 Other requirements. 

Vehicles required to meet the emission standards of this part must meet the following 

additional requirements, except as noted elsewhere in this part: 

(a) Adjustable parameters. Vehicles that have adjustable parameters must meet all the 

requirements of this part for any adjustment in the physically adjustable range. We may 

require that you set adjustable parameters to any specification within the adjustable range 

during any testing. See 40 CFR part 86 for information related to determining whether or 

not an operating parameter is considered adjustable. You must ensure safe vehicle 

operation throughout the physically adjustable range of each adjustable parameter, 

including consideration of production tolerances. Note that adjustable roof fairings are 

deemed to not to be adjustable parameters. 

(b) Prohibited controls. You may not design your vehicles with emission control devices, 

systems, or elements of design that cause or contribute to an unreasonable risk to public 

health, welfare, or safety while operating. For example, this would apply if the vehicle 

emits a noxious or toxic substance it would otherwise not emit that contributes to such an 

unreasonable risk. 

(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 86.166-12. 

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. 
(1) For purpose of this requirement, “refrigerant capacity” is the total mass of 

refrigerant recommended by the vehicle manufacturer as representing a full charge. 

Where full charge is specified as a pressure, use good engineering judgment to 

convert the pressure and system volume to a mass. 

(2) 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 86.1866-12. 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. 

(3) If your total refrigerant capacity is less than 734 grams, your leakage rate may 

exceed 1.50 percent, as long as the total leakage rate does not exceed 11.0 g/yr. If 

your system uses a refrigerant other than HFC–134a, you may adjust your leakage 

rate as specified in paragraph (c)(2) of this section.

 

§ 1037.120 Emission-related warranty requirements. 

(a) General requirements. You must warrant to the ultimate purchaser and each 

subsequent purchaser that the new vehicle, including all parts of its emission control 

system, meets two conditions: 

(1) It is designed, built, and equipped so it conforms at the time of sale to the ultimate 

purchaser with the requirements of this part. 

(2) It is free from defects in materials and workmanship that may keep it from 

meeting these requirementscause the vehicle to fail to conform to the requirements of 

this part during the applicable warranty period. 

(b) Warranty period. (1) Your emission-related warranty must be valid for at least: 

(i) 5 years or 50,000 miles for spark-ignition vehicles and light heavy-duty 

vehicles. 

(ii) 5 years or 100,000 miles for medium and heavy heavy-duty vehicles. 

. 

(iii) 2 years or 24,000 miles for tires.

(2) You may offer an emission-related warranty more generous than we require. The 

emission-related warranty for the vehicle may not be shorter than any basic 

mechanical warranty you provide with orto that owner without charge for the vehicle. 

Similarly, the emission-related warranty for any component may not be shorter than 

any warranty you provide to that owner with or without charge for that component. 

This means that your warranty for a given vehicle may not treat emission-related and 

nonemission-related defects differently for any component. The warranty period 

begins when the vehicle is placed into service. 

(c) Components covered. The emission-related warranty covers vehicle speed limiters, 

idle shutdown systems, fairings, and hybrid system components, to the extent such

emission-related components are included in the certified emission controls. The 

emission-related warranty covers tires and all components whose failure would increase a 

vehicle's evaporative emissions (for vehicles subject to evaporative emission standards). 

The emission-related warranty covers these components even if another company 

produces the component. Your emission-related warranty does not need to cover 
components whose failure would not increase a vehicle's emissions of any regulated 

pollutant. 

(d) Limited applicability. You may deny warranty claims under this section if the 

operator caused the problem through improper maintenance or use, as described in 40 

CFR 1068.115. 

(e) Owners manual. Describe in the owners manual the emission-related warranty 

provisions from this section that apply to the vehicle. 

§ 1037.125 Maintenance instructions and allowable maintenance. 

Give the ultimate purchaser of each new vehicle written instructions for properly 

maintaining and using the vehicle, including the emission control system. The 

maintenance instructions also apply to service accumulation on any of your emission-data 

vehicles. See paragraph (i) of this section for requirements related to tire replacement. 

(a) Critical emission-related maintenance. Critical emission-related maintenance 

includes any adjustment, cleaning, repair, or replacement of critical emission-related 

components. This may also include additional emission-related maintenance that you 

determine is critical if we approve it in advance. You may schedule critical emissionrelated maintenance on these components if you demonstrate that the maintenance is 

reasonably likely to be done at the recommended intervals on in-use vehicles. We will 

accept scheduled maintenance as reasonably likely to occur if you satisfy any of the 

following conditions: 

(1) You present data showing that, if a lack of maintenance increases emissions, it 

also unacceptably degrades the vehicle’s performance. 

(2) You present survey data showing that at least 80 percent of vehicles in the field 

get the maintenance you specify at the recommended intervals. 

(3) You provide the maintenance free of charge and clearly say so in your 

maintenance instructions. 

(4) You otherwise show us that the maintenance is reasonably likely to be done at the 

recommended intervals. 

 (b) Recommended additional maintenance. You may recommend any additional amount 

of maintenance on the components listed in paragraph (a) of this section, as long as you 

state clearly that these maintenance steps are not necessary to keep the emission-related 

warranty valid. If operators do the maintenance specified in paragraph (a) of this section, 

but not the recommended additional maintenance, this does not allow you to disqualify 

those vehicles from in-use testing or deny a warranty claim. Do not take these 

maintenance steps during service accumulation on your emission-data vehicles. 

(c) Special maintenance. You may specify more frequent maintenance to address 

problems related to special situations, such as atypical vehicle operation. You must 

clearly state that this additional maintenance is associated with the special situation you 

are addressing. We may disapprove your maintenance instructions if we determine that 

you have specified special maintenance steps to address vehicle operation that is not 

atypical, or that the maintenance is unlikely to occur in use. If we determine that certain 

maintenance items do not qualify as special maintenance under this paragraph (c), you 

may identify this as recommended additional maintenance under paragraph (b) of this 

section. 

(d) Noncritical emission-related maintenance. Subject to the provisions of this paragraph 
(d), you may schedule any amount of emission-related inspection or maintenance that is 

not covered by paragraph (a) of this section (that is, maintenance that is neither explicitly 

identified as critical emission-related maintenance, nor that we approve as critical 

emission-related maintenance). Noncritical emission-related maintenance generally 

includes maintenance on the components we specify in 40 CFR part 1068, Appendix I, 

that is not covered in paragraph (a) of this section. You must state in the owners manual 

that these steps are not necessary to keep the emission-related warranty valid. If 

operators fail to do this maintenance, this does not allow you to disqualify those vehicles 

from in-use testing or deny a warranty claim. Do not take these inspection or 

maintenance steps during service accumulation on your emission-data vehicles. 

(e) Maintenance that is not emission-related. For maintenance unrelated to emission 

controls, you may schedule any amount of inspection or maintenance. You may also take 

these inspection or maintenance steps during service accumulation on your emission-data 

vehicles, as long as they are reasonable and technologically necessary. This might 

include adding engine oil, changing air, fuel, or oil filters, servicing engine-cooling 

systems, and adjusting idle speed, governor, engine bolt torque, valve lash, or injector 

lash. You may perform this nonemission-related maintenance on emission-data vehicles 

at the least frequent intervals that you recommend to the ultimate purchaser (but not the 

intervals recommended for severe service). 

(f) Source of parts and repairs. State clearly on the first page of your written maintenance 

instructions that a repair shop or person of the owner's choosing may maintain, replace, 

or repair emission control devices and systems. Your instructions may not require 

components or service identified by brand, trade, or corporate name. Also, do not 

directly or indirectly condition your warranty on a requirement that the vehicle be 

serviced by your franchised dealers or any other service establishments with which you 

have a commercial relationship. You may disregard the requirements in this paragraph 

(f) if you do one of two things: 

(1) Provide a component or service without charge under the purchase agreement. 

(2) Get us to waive this prohibition in the public’s interest by convincing us the 

vehicle will work properly only with the identified component or service. 

(g) [Reserved] 

(h) Owners manual. Explain the owner’s responsibility for proper maintenance in the 

owners manual. 

(i) Tire maintenance and replacement. Include instructions that will enable the owner to 

replace tires so that the vehicle conforms to the original certified vehicle configuration. 

§ 1037.135 Labeling. 

(a) Assign each vehicle a unique identification number and permanently affix, engrave, or 

stamp it on the vehicle in a legible way. For example, The vehicle identification number 

(VIN) serves this purpose. 

(b) At the time of manufacture, affix a permanent and legible label identifying each 

vehicle. The label must be– 

(1) Attached in one piece so it is not removable without being destroyed or defaced. 

(2) Secured to a part of the vehicle needed for normal operation and not normally 

requiring replacement. 

(3) Durable and readable for the vehicle’s entire life. 
(4) Written in English. 

(c) The label must— 

(1) Include the heading "VEHICLE EMISSION CONTROL INFORMATION". 

(2) Include your full corporate name and trademark. You may identify another 

company and use its trademark instead of yours if you comply with the branding 

provisions of 40 CFR 1068.45. 

(3) Include EPA’s standardized designation for the vehicle family (and subfamily, 

where applicable)..

(4) State the regulatory sub-category that determines the applicable emission 

standards for the vehicle family (see definition in § 1037.801). 

(5) State the date of manufacture [DAY (optional), MONTH, and YEAR]. You may 

omit this from the label if you keep a record ofstamp, engrave, or otherwise 

permanently identify it elsewhere on the vehicle-manufacture dates and provide it to 

us upon requestengine, in which case you must also describe in your application for 

certification where you will identify the date on the engine. 

 (6) Identify the emission control system. Use terms and abbreviations as described 

in 40 CFR 1068.45Appendix III to this part or other applicable conventions. 

(7) Identify any requirements for fuel and lubricants that do not involve fuel-sulfur 

levels. 

(8) State: "THIS VEHICLE COMPLIES WITH U.S. EPA REGULATIONS FOR 

[MODEL YEAR] HEAVY-DUTY VEHICLES." 

(9) Include the following statement, 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. 

(d) You may add information to the emission control information label to identify other 

emission standards that the vehicle meets or does not meet (such as European standards). 

You may also add other information to ensure that the vehicle will be properly 

maintained and used. However, if you provide additional information on the label, you 

may not omit any required information on the basis that a label containing all of the 

required information will not fit on the vehicle

(e) You may ask us to approve modified labeling requirements in this part 1037 if you 

show that it is necessary or appropriate. We will approve your request if your alternate 

label is consistent with the requirements of this part. 

§ 1037.140 Curb weight and roof height. 

(a) Where applicable, a vehicle’s curb weight and roof height are determined from 

nominal design specifications, as provided in this section. Round the weight to the 

nearest pound and height to the nearest inch. Base roof height on fully inflated tires 

having a static loaded radius equal to the arithmetic mean of the largest and smallest 

static loaded radius of tires you offer. or a standard tire we approve.

(b) The nominal design specifications must be within the range of the actual weights and 

roof heights of production vehicles considering normal production variability. If after 

production begins it is determined that your nominal design specifications do not 

represent production vehicles, we may require you to amend your application for 

certification under § 1037.225. 
(c) If your vehicle is equipped with an adjustable roof fairing, measure the roof height 

with the fairing in its lowest setting. 

§ 1037.150 Interim provisions. 

The provisions in this section apply instead of other provisions in this part. 

(a) Incentives for early introduction. The provisions of this paragraph (a) apply with 

respect to vehicles produced in model years before 2014 Manufacturers may voluntarily 

certify in model year 2013 (or earlier model years for electric vehicles) to the greenhouse 

gas standards of this part. 

(1) This paragraph (a)(1) applies for regulatory sub-categories subject to to the standards 

of §1037.105 or 1037.106. Except as specified in paragraph (a)(23) 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 subcategory to these standards. Except as specified in paragraph(a)(4) of this section, if 

some vehicle families within a regulatory sub-category are certified after the start of the 

model year, you may generate credits only for production that occurs after all families are 

certified. For example, if you produce three vehicle families in an averaging set and you 

receive your certificates for those families on January 4, 2013, March 15, 2013, and April 

24, 2013, you may not generate credits for model year 2013 production in any of the 

families that occurs before April 24, 2013. Calculate credits relative to the standard that 

would apply in model year 2014 using the equations in subpart H of this part. You may 

bank credits equal to the surplus credits you generate under this paragraph (a) multiplied 

by 1.50. For example, if you have 1.0 Mg of surplus credits for model year 2013, you 

may bank 1.5 Mg of credits. Credit deficits for an averaging set prior to model year 2014 

do not carry over to model year 2014. 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 of your intent to use this provision before submitting your applications.

(2) This paragraph (a)(1) applies for regulatory sub-categories subject to to the 

standards of §1037.104. 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. 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 groupsare certified. 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 of your intent to use this 

provision before submitting your applications. 

(2) This paragraph (a)(2) applies for regulatory sub-categories subject to the standards 

of §1037.104. 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. 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. 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 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 of your intent to use this provision before 

submitting your applications.

(3) You may generate emission credits for the number of additional SmartWay 

designated tractors (relative to your 2012 production).), provided you do not generate 

credits for those vehicles under paragraph (a)(1) of this section. Calculate credits for 

each regulatory sub-category relative to the standard that would apply in model year 

2014 using the equations in subpart H of this part. Use a production volume equal to 

the number of verifieddesignated model year 2013 SmartWay tractors minus the 

number of verifieddesignated model year 2012 SmartWay tractors. You may bank 

credits equal to the surplus credits you generate under this paragraph multiplied by 

1.50. Your 2012 and 2013 model years must be equivalent in length. 

(4) This paragraph (a)(4) applies where you do not receive your final certificate in a 

regulatory sub-category within 30 days of submitting your final application for that 

sub-category. Calculate your credits for all production that occurs 30 days or more 

after you submit your final application for the sub-category. 

(b) Phase-in provisions. Each manufacturer must choose one of the following options for 

phasing in the standards of § 1037.104: 

(1) To implement the phase-in under this paragraph (b)(1), the standards in 

§ 1037.104 apply as specified for model year 2018, with compliance for those 

vehicles in model years 2014 through 2017 based on the CO2 target values specified 

in the following table: 

Table 1 to § 1037.150 

Model Year and Engine Cycle Alternate CO2 Target (g/mile) 

2014 Spark-Ignition [0.0482 × (WF)] + 371 

2015 Spark-Ignition [0.0479 × (WF)] + 369 

2016 Spark-Ignition [0.0469 × (WF)] + 362 

2017 Spark-Ignition [0.0460 × (WF)] + 354

2014 Compression-Ignition [0.0478 × (WF)] + 368 

2015 Compression-Ignition [0.0474 × (WF)] + 366 

2016 Compression-Ignition [0.0460 × (WF)] + 354 

2017 Compression-Ignition [0.0445 × (WF)] + 343 

 

(2) To implement the phase in under this paragraph (b)(2), the standards in 

§ 1037.104 apply as specified for model year 2019, with compliance for those 

vehicles in model years 2014 through 2018 based on the CO2 target values specified 

in the following table: 
Table 2 to § 1037.150 

Model Year and Engine Cycle Alternate CO2 Target (g/mile) 

2014 Spark-Ignition [0.0482 × (WF)] + 371 

2015 Spark-Ignition [0.0479 × (WF)] + 369 

2016-2018 Spark-Ignition [0.0456 × (WF)] + 352 

2014 Compression-Ignition [0.0478 × (WF)] + 368 

2015 Compression-Ignition [0.0474 × (WF)] + 366 

2016-2018 Compression-Ignition [0.0440 × (WF)] + 339 

(c) Provisions for small manufacturers. Manufacturers meeting the small business 

criteria specified in 13 CFR 121.201 for “Heavy Duty Truck Manufacturing” are not 

subject to the greenhouse gas standards of §§ 1037.104 through 1037.106, as specified in 

this paragraph (c). Qualifying manufacturers must notify the Designated Compliance 

Officer each model year before introducing these excluded vehicles into U.S. commerce. 

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 with the 

following statement: “THIS VEHICLE IS EXCLUDED UNDER 40 CFR 1037.150(c).”

in order for this exclusion to be valid.).”.

(d) Air conditioning leakage for vocational vehicles. The air conditioning leakage 

standard of § 1037.115 does not apply for vocational vehicles. 

(e) Model year 2014 N2O standards. In model year 2014 and earlier, manufacturers may

show compliance with the N2O standards using an engineering analysis. However, This 

allowance also applies for later test groups families carried over from model 2014

consistent with the provisions of 40 CFR 86.1839. You may not certify to an N2O FEL 

different than the standard without measuring N2O emissions. 

(f) Electric vehicles. All electric vehicles are deemed to have zero emissions of CO2, 

CH4, and N2O. No emission testing is required for such electric vehicles. 

(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. You must label model year 2014 vehicles 

excluded under this paragraph (g) with the following statement: “THIS VEHICLE IS 

EXCLUDED UNDER 40 CFR 1037.150(g).” 

(h) Alternate certification procedures. Manufacturers may ask us to modify the 

administrative requirements for certification for model years before 2015.

(i) (h) Off-road vehicle exemption. In unusual circumstances, vehicle manufacturers may 

ask us to exempt vehicles under §1037.631 based on other criteria that are equivalent to 

those specified in §1037.631(a). For example, we would normally not grant relief in 

cases where the vehicle manufacturer had credits or other compliant tires were available.

(i) Credit multiplier for advanced technology. If you generate credits from vehicles 

certified for advancewith advanced technology, you may multiply these credits by 1.50, 

except that you may not apply this multiplier andin addition to the early-credit multiplier 

of paragraph (a) of this section. 

(j) Limited prohibition related to early model year engines. The prohibition in §1037.601 

against introducing into U.S. commerce a vehicle containing an engine not certified to the 

standards of this part does not apply for vehicles using model year 2014 or 2015 spark-
ignition engines, or any model year 2013 or earlier engines.

(k) Verifying drag areas from in-use vehicles. We may measure the drag area of your 

vehicles after they have been placed into service. Your vehicle conforms to the 

regulations of this part with respect to aerodynamic performance if we measure its drag 

area to be at or below the maximum drag area allowed for the bin to which that 

configuration was certified. To account for measurement variability, your vehicle is also 

deemed to conform to the regulations of this part with respect to aerodynamic 

performance if we measure its drag area to at or below the maximum drag area allowed 

for the bin above the bin to which you certified (for example, Bin II if you certified the 

vehicle to Bin III), unless we determine that you knowingly produced the vehicle to have 

a higher drag area than is allowed for the bin to which it was certified. 

(l) Optional certification under §1037.104. You may certify certain complete or cabcomplete vehicles to the standards of §1037.104. All vehicles optionally certified under 

this paragraph (l) are deemed to be subject to the standards of §1037.104. Note that 

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 does not allow you to chassis-certify these vehicles with respect to criteria 

emissions.

(1) You may certify complete or cab-complete spark-ignition vehicles to the 

standards of §1037.104. 

(2) You may apply the provisions of §1037.104 to cab-complete vehicles based on a 

complete sister vehicle. In unusual circumstances, you may ask us to apply these 

provisions to Class 2b or 3 incomplete vehicles that do not meet the definition of cabcomplete. Except as specified in paragraph (l)(3) of this section, for purposes of 

§1037.104, a complete sister vehicle is a complete vehicle of the same vehicle 

configuration (as defined in §1037.104) as the cab-complete vehicle. Calculate the 

target value under §1037.104(a) based on the same work factor value that applies for 

the complete sister vehicle. Test these cab-complete vehicles using the same 

equivalent test weight and other dynamometer settings that apply for the complete 

vehicle from which you used the work factor value. For certification, you may 

submit the test data from that complete sister vehicle instead of performing the test on 

the cab-complete vehicle. You are not required to produce the complete sister vehicle 

for sale to use the provisions of this paragraph (l)(2). This means the complete sister 

vehicle may be a carryover vehicle from a prior model year or a vehicle created solely 

for the purpose of testing.

(3) You may use as complete sister vehicle a complete vehicle that is not of the same 

vehicle configuration as the cab-complete vehicle as specified in this paragraph (l)(3). 

This allowance applies where the complete vehicle is not of the same vehicle 

configuration as the cab-complete vehicle only because of factors unrelated to 

coastdown performance. If your complete sister vehicle is covered by this paragraph 

(l)(3), you may not submit the test data from that complete sister vehicle and must 

perform the test on the cab-complete vehicle.

(m) Loose engine sales. This paragraph (m) applies for spark-ignition engines identical 

to engines used in vehicles certified to the standards of §1037.104, where you sell such 

engines as loose engines or as engines installed in incomplete vehicles that are not cabcomplete vehicles. For purposes of this paragraph (m), engines would not be considered 
to be identical if they used different engine hardware. You may include such engines in a 

test group certified to the standards of §1037.104, subject to the following provisions:

(1) Engines certified under this paragraph (m) are deemed to be certified to the 

standards of 40 CFR 1036.108 as specified in 40 CFR 1036.108(a)(4).

(2) The U.S.-directed production volume of engines you sell as loose engines or 

installed in incomplete heavy-duty vehicles that are not cab-complete vehicles in any 

given model year may not exceed ten percent of the total U.S-directed production 

volume of engines of that design that you produce for heavy-duty applications for that 

model year, including engines you produce for complete vehicles, cab-complete 

vehicles, and other incomplete vehicles. The total number of engines you may 

certify under this paragraph (m), of all engine designs, may not exceed 15,000 in any 

model year. Engines produced in excess of either of these limits are not covered by 

your certificate. For example, if you produce 80,000 complete model year 2017 Class 

2b pickup trucks with a certain engine and 10,000 incomplete model year 2017 Class 

3 vehicles with that same engine, and you do not apply the provisions of this 

paragraph (m) to any other engine designs, you may produce up to 10,000 engines of 

that design for sale as loose engines under this paragraph (m). If you produced 

11,000 engines of that design for sale as loose engines, the last 1,000 of them that you 

produced in that model year 2017 would be considered uncertified. 

(3) This paragraph (m) does not apply for engines certified to the standards of 40 

CFR 1036.108(a)(1).

(4) Label the engines as specified in 40 CFR 1036.135 including the following 

compliance statement: “THIS ENGINE WAS CERTIFIED TO THE ALTERNATE 

GREENHOUSE GAS EMISSION STANDARDS OF 40 CFR 1036.108(a)(4).” List 

the test group name instead of an engine family name.

(5) Vehicles using engines certified under this paragraph (m) are subject to the 

emission standards of §1037.105.

(6) For certification purposes, your engines are deemed to have a CO2 target value 

and test result equal to the CO2 target value and test result for the complete vehicle in 

the applicable test group with the highest equivalent test weight, except as specified 

in paragraph (m)(6)(ii) of this section. Use these values to calculate your target value, 

fleet-average emission rate, and in-use emission standard. Where there are multiple 

complete vehicles with the same highest equivalent test weight, select the CO2 target 

value and test result as specified in paragraphs (m)(6)(i) and (ii) of this section:

(i) If one or more of the CO2 test results exceed the applicable target value, use 

the CO2 target value and test result of the vehicle that exceeds its target value by 

the greatest amount.

(ii) If none of the CO2 test results exceed the applicable target value, select the 

highest target value and set the test result equal to it. This means that you may 

not generate emission credits from vehicles certified under this paragraph (m).

(7) State in your applications for certification that your test group and engine family 

will include engines certified under this paragraph (m). This applies for your 

greenhouse gas vehicle test group and your criteria pollutant engine family. List in 

each application the name of the corresponding test group/engine family.

Subpart C—Certifying Vehicle families 
§ 1037.201 General requirements for obtaining a certificate of conformity. 

(a) You must send us a separate application for a certificate of conformity for each 

vehicle family. A certificate of conformity is valid from the indicated effective date until 

December 31the end of the model year for which it is issued, which may not extend 

beyond December 31 of that year. You must renew your certification annually for any 

vehicles you continue to produce. 

(b) The application must contain all the information required by this part and must not 

include false or incomplete statements or information (see § 1037.255). 

(c) We may ask you to include less information than we specify in this subpart, as long as 

you maintain all the information required by § 1037.250. 

(d) You must use good engineering judgment for all decisions related to your application 

(see 40 CFR 1068.5). 

(e) An authorized representative of your company must approve and sign the application. 

(f) See § 1037.255 for provisions describing how we will process your application. 

(g)(g) We may perform confirmatory testing on your vehicles; for example, we may test 

vehicles to verify drag areas or other GEM inputs. 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. 

 

§ 1037.205 What must I include in my application? 

This section specifies the information that must be in your application, unless we ask you 

to include less information under § 1037.201(c). We may require you to provide 

additional information to evaluate your application. Note that references to testing and 

emission-data vehicles refer to testing vehicles to measure aerodynamic drag, assess 

hybrid vehicle performance, and/or measure evaporative emissions. 

(a) Describe the vehicle family’s specifications and other basic parameters of the 

vehicle’s design and emission controls. List the fuel type on which your vehicles are 

designed to operate (for example, ultra low-sulfur diesel fuel). List each distinguishable 

vehicle configuration in the vehicle family.

(b) Explain how the emission control system operates. As applicable, describe in detail 

all system components for controlling greenhouse gas and evaporative emissions, 

including all auxiliary emission control devices (AECDs) and all fuel-system components 

you will install on any production vehicle. Identify the part number of each component 

you describe. For this paragraph (b), treat as separate AECDs any devices that modulate 

or activate differently from each other.

(c) [Reserved] 

(c) For vehicles subject to air conditioning standards, include:

(1) The refrigerant leakage rates (leak scores).

(2) The refrigerant capacity of the air conditioning systems.

(3) The corporate name of the final installer of the air conditioning system.

(d) Describe any vehicles you selected for testing and the reasons for selecting them. 

(e) Describe any test equipment and procedures that you used, including any special or 

alternate test procedures you used (see § 1037.501). 
(f) Describe how you operated any emission-data vehicle before testing, including the 

duty cycle and the number of vehicle operating miles used to stabilize emission levels. 

Explain why you selected the method of service accumulation. Describe any scheduled 

maintenance you did. 

(g) List the specifications of any test fuel to show that it falls within the required ranges 

we specify in 40 CFR part 1065. 

(h) Identify the vehicle family’s useful life. 

(i) Include the maintenance instructions and warranty statement you will give to the 

ultimate purchaser of each new vehicle (see §§§ 1037.120 and 1037.125). 

(j) Describe your emission control information label (see § 1037.135). 

(k) Identify the emission standards or FELs to which you are certifying vehicles in the 

vehicle family. For families containing multiple subfamilies, this means that you must 

identify multiple CO2 FELs. For example, you may identify the FELs for each 

subfamily. highest and lowest FELs to which any of your subfamilies will be certified 

and also list all possible FELs in between (which will be in 1 g/ton-mile increments).

(l) Where applicable, identify the vehicle family’s deterioration factors and describe how 

you developed them. Present any emission test data you used for this. (see 

§1037.241(c).))).

(m) Where applicable, state that you operated your emission-data vehicles as described in 

the application (including the test procedures, test parameters, and test fuels) to show you 

meet the requirements of this part. 

(n) Present evaporative test data to show your vehicles meet the evaporative emission 

standards we specify in subpart B of this part, if applicable. Report all valid test results,

from emission-data vehicles and indicate whether there are test results from invalid tests 

or from any other tests of the emission-data vehicle, whether or not they were conducted 

according to the test procedures of subpart F of this part. We may require you to report 

suchthese additional test results. We may ask you to send other information to confirm 

that your tests were valid under the requirements of this part and 40 CFR part 86. 

(o) Report modeling results for ten configurations. Include modeling inputs and detailed 

descriptions of how they were derived. Unless we specify otherwise, include the 

configuration with the highest modeling result, the lowest modeling result, and the 

configurations with the highest projected sales. 

(p) Describe all adjustable operating parameters (see § 1037.115(a)),), including 

production tolerances. You do not need to include parameters that do not affect 

emissions covered by your application. Include the following in your description of each 

parameter: 

(1) The nominal or recommended setting. 

(2) The intended physically adjustable range. 

(3) The limits or stops used to establish adjustable ranges. 

(4) Information showing why the limits, stops, or other means of inhibiting 

adjustment are effective in preventing adjustment of parameters on in-use vehicles to 

settings outside your intended physically adjustable ranges. 

(q) [Reserved] 

(r) Unconditionally certify that all the vehicles in the vehicle family comply with the 

requirements of this part, other referenced parts of the CFR, and the Clean Air Act. 

(s) Include good-faith estimates of U.S.-directed production volumes. Include a 
justification for the estimated production volumes if they are substantially different than 

actual production volumes in earlier years for similar vehicle models by subfamily. We 

may require you to describe the basis of your estimates. 

(t) Include the information required by other subparts of this part. For example, include 

the information required by § 1037.725 if you participate in the ABT program. 

(u) Include other applicable information, such as information specified in this part or 40 

CFR part 1068 related to requests for exemptions. 

(v) Name an agent for service located in the United States. Service on this agent 

constitutes service on you or any of your officers or employees for any action by EPA or 

otherwise by the United States related to the requirements of this part. 

§ 1037.210 Preliminary approval before certification. 

If you send us information before you finish the application, we may review it and make 

any appropriate determinations. Decisions made under this section are considered to be 

preliminary approval, subject to final review and approval. We will generally not reverse 

a decision where we have given you preliminary approval, unless we find new 

information supporting a different decision. If you request preliminary approval related to 

the upcoming model year or the model year after that, we will make best-efforts to make 

the appropriate determinations as soon as practicable. We will generally not provide 

preliminary approval related to a future model year more than two years ahead of time. 

§ 1037.220 Amending maintenance instructions. 

You may amend your emission-related maintenance instructions after you submit your 

application for certification as long as the amended instructions remain consistent with 

the provisions of § 1037.125. You must send the Designated Compliance Officer a 

written request to amend your application for certification for a vehicle family if you 

want to change the emission-related maintenance instructions in a way that could affect 

emissions. In your request, describe the proposed changes to the maintenance 

instructions. If operators follow the original maintenance instructions rather than the 

newly specified maintenance, this does not allow you to disqualify those vehicles from 

in-use testing or deny a warranty claim. 

(a) If you are decreasing or eliminating any specified maintenance, you may distribute the 

new maintenance instructions to your customers 30 days after we receive your request, 

unless we disapprove your request. This would generally include replacing one 

maintenance step with another. We may approve a shorter time or waive this 

requirement. 

(b) If your requested change would not decrease the specified maintenance, you may 

distribute the new maintenance instructions anytime after you send your request. For 

example, this paragraph (b) would cover adding instructions to increase the frequency of 

filter changes for vehicles in severe-duty applications. 

(c) You need not request approval if you are making only minor corrections (such as 

correcting typographical mistakes), clarifying your maintenance instructions, or changing 

instructions for maintenance unrelated to emission control. We may ask you to send us 

copies of maintenance instructions revised under this paragraph (c). 

§ 1037.225 Amending applications for certification. 
Before we issue you a certificate of conformity, you may amend your application to 

include new or modified vehicle configurations, subject to the provisions of this section. 

After we have issued your certificate of conformity, you may send us an amended 

application requesting that we include new or modified vehicle configurations within the 

scope of the certificate, subject to the provisions of this section. You must amend your 

application if any changes occur with respect to any information that is included or 

should be included in your application. 

(a) You must amend your application before you take any of the following actions: 

(1) Add a vehicle configuration to a vehicle family. In this case, the vehicle 

configuration added must be consistent with other vehicle configurations in the 

vehicle family with respect to the criteria listed in § 1037.230. 

(2) Change a vehicle configuration already included in a vehicle family in a way that 

may affect emissions, or change any of the components you described in your 

application for certification. This includes production and design changes that may 

affect emissions any time during the vehicle's lifetime. 

(3) Modify an FEL for a vehicle family as described in paragraph (f) of this section. 

(b) To amend your application for certification, send the relevant information to the 

Designated Compliance Officer. 

(1) Describe in detail the addition or change in the vehicle model or configuration you 

intend to make. 

(2) Include engineering evaluations or data showing that the amended vehicle family 

complies with all applicable requirements. You may do this by showing that the 

original emission-data vehicle is still appropriate for showing that the amended 

family complies with all applicable requirements. 

(3) If the original emission-data vehicle or emission modeling for the vehicle family 

is not appropriate to show compliance for the new or modified vehicle configuration, 

include new test data or emission modeling showing that the new or modified vehicle 

configuration meets the requirements of this part. 

(c) We may ask for more test data or engineering evaluations. You must give us these 

within 30 days after we request them. 

(d) For vehicle families already covered by a certificate of conformity, we will determine 

whether the existing certificate of conformity covers your newly added or modified 

vehicle. You may ask for a hearing if we deny your request (see § 1037.820). 

(e) For vehicle families already covered by a certificate of conformity, you may start 

producing the new or modified vehicle configuration anytime after you send us your 

amended application and before we make a decision under paragraph (d) of this section. 

However, if we determine that the affected vehicles do not meet applicable requirements, 

we will notify you to cease production of the vehicles and may require you to recall the 

vehicles at no expense to the owner. Choosing to produce vehicles under this paragraph 

(e) is deemed to be consent to recall all vehicles that we determine do not meet applicable 

emission standards or other requirements and to remedy the nonconformity at no expense 

to the owner. If you do not provide information required under paragraph (c) of this 

section within 30 days after we request it, you must stop producing the new or modified 

vehicles. 

(f) You may ask us to approve a change to your FEL in certain cases after the start of 

production. The changed FEL may not apply to vehicles 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 vehicles produced after the change. You may ask us to approve 

a change to your FEL in the following cases: 

(1) You may ask to raise your FEL for your vehicle subfamily at any time. In your 

request, you must show that you will still be able to meet the emission standards as 

specified in subparts B and H of this part. Use the appropriate FELs with 

corresponding production volumes to calculate emission credits for the model year, as 

described in subpart H of this part. 

(2) Where testing applies, you may ask to lower the FEL for your vehicle subfamily 

only if you have test data from production vehicles showing that emissions are below 

the proposed lower FEL. Otherwise, you may ask to lower your FEL for your vehicle 

subfamily at any time. The lower FEL applies only to vehicles you produce after we 

approve the new FEL. Use the appropriate FELs with corresponding production 

volumes to calculate emission credits for the model year, as described in subpart H of 

this part. 

(3) You may ask to add an FEL for your vehicle family at any time. 

§ 1037.230 Vehicle families, sub-families, and configurations. 

(a) For purposes of certifying your vehicles to greenhouse gas standards, divide your 

product line into families of vehicles as specified in this section. . Your vehicle family is 

limited to a single model year. Group vehicles in the same vehicle family if they are the 

same in all the following aspects: 

(1) The regulatory sub-category (or equivalent in the case of vocational tractors), as 

follows: 

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

(ii) Vocational vehicles (other than vocational tractors) above 19,500 pounds 

GVWR butand at or below 33,000 pounds GVWR. 

(iii) Vocational vehicles (other than vocational tractors) above 33,000 pounds 

GVWR. 

(iv) Low-roof day cab tractors above 26,000 pounds GVWR butand at or below 

33,000 pounds GVWR 

(v) Mid-roof day cab tractors above 26,000 pounds GVWR butand at or below 

33,000 pounds GVWR. 

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

pounds GVWR. 

(vii) Low-roof day cab tractors above 33,000 pounds GVWR. 

(viii) Low-roof sleeper cab tractors above 33,000 pounds GVWR. 

(ix) Mid-roof day cab tractors above 33,000 pounds GVWR. 

(x) Mid-roof sleeper cab tractors above 33,000 pounds GVWR. 

(xi) High-roof day cab tractors above 33,000 pounds GVWR. 

(xii) High-roof sleeper cab tractors above 33,000 pounds GVWR. 

(xiii) Vocational tractors. 

(2) Vehicle technology as follows: 

(i) Group together vehicles that do not contain advanced or innovative 

technologies. 
(ii) Group together vehicles that contain the same advanced/innovative 

technologies. 

(b) If the vehicles in your family are being certified to more than one FEL, subdivide 

your greenhouse gas vehicle families into subfamilies that include vehicles with identical 

FELs. Note that you may add subfamilies at any time during the model year. 

(c) Group vehicles into configurations consistent with the definition of “vehicle 

configuration” in §1037.801. Note that vehicles with hardware or software differences 

that are related to measured or modeled emissions are considered to be different vehicle 

configurations even if they have the same GEM inputs and FEL. Note also, that you are 

not required to separately identify all configurations for certification See paragraph (g) 

of this section for provisions allowing you to group certain hardware differences into the 

same configuration. Note that you are not required to identify all possible configurations 

for certification; also, you are required to include in your end-of year report only those 

configurations you produced.

(d) For a vehicle model that straddles a roof-height, cab type, or GVWR division, you 

may include all the vehicles in the same vehicle family if you certify the vehicle family to 

the more stringent standards. For roof height, this means you must certify to the taller 

roof standards. For cab-type and GVWR, this means you must certify to the numerically 

lower standards. 

(e) Divide your vehicles that are subject to evaporative emission standards into groups of 

vehicles with similar physical features expected to affect evaporative emissions. Group 

vehicles in the same evaporative emission family if they are the same in all the following 

aspects, unless we approve a better way of grouping vehicles into families that have 

similar emission control characteristics:

(1) Method of vapor storage, including the number of vapor storage devices, the 

working material, and the total working capacity of vapor storage (as determined 

under 40 CFR 86.1232-96(h)(1)(iv)). You may consider the working capacity to be 

the same if the values differ by 20 grams or less.

(2) Method of purging stored vapors.

(3) Material for liquid fuel hose.

(e) [Reserved.]

(f) You may divide your families into more families than is specified in this section. 

(g) You may ask us to allow you to group into the same configuration vehicles that have 

very small body hardware differences that do not significantly affect drag areas. Note 

that this allowance does not apply for substantial differences, even if the vehicles have

the same measured drag areas. 

§ 1037.241 Demonstrating compliance with exhaust emission standards for 

greenhouse gas pollutants. 

(a) For purposes of certification, your vehicle family is considered in compliance with the 

emission standards in § 1037.105 or § 1037.106 if all vehicle configurations in that 

family have modeled CO2 emission rates (as specified in subpart F of this part) at or 

below the applicable standards. See 40 CFR part 86, subpart S, for showing compliance 

with the standards of § 1037.104. Note that your FELs are considered to be the 

applicable emission standards with which you must comply if you participate in the ABT 

program in subpart H of this part. 
(b) Your vehicle family is deemed not to comply if any vehicle configuration in that 

family has a modeled CO2 emission rate that is above its FEL. 

(c) We may require you to provide an engineering analysis showing that the performance 

of your emission controls will not deteriorate during the useful life with proper 

maintenance. If we determine that your emission controls are likely to deteriorate during 

the useful life, we may require you to develop and apply deterioration factors (DFs) 

consistent with good engineering judgment. For example, you may need to apply a 

DFdeterioration factor to address deterioration of battery performance for a hybrid-an 

electric hybrid vehicle. Where the highest useful life emissions occur between the end of 

useful life and at the low-hour test point, base deterioration factors for the vehicles on the 

difference between (or ratio of) the point at which the highest emissions occur and the 

low-hour test point. 

§ 1037.243 Demonstrating compliance with evaporative emission standards.

(a) For purposes of certification, your evaporative emission family is considered in 

compliance with the evaporative emission standards in subpart B of this part if you do 

either of the following:

(1) You have valid test results showing emission levels at or below the standards in 

§ 1037.103.

(2) For vehicles above 26,000 pounds GVWR, you prepare an engineering analysis 

showing that your vehicles in the family will comply with applicable standards 

throughout the useful life.

(b) Your evaporative emission family is deemed not to comply if any vehicle 

representing the family has valid test results showing emission levels above any of the 

standards in § 1037.103, with or without deterioration factors. For vehicles above 26,000 

pounds GVWR, your evaporative emission family is deemed not to comply if your 

engineering analysis is not adequate to show that all the vehicles in the family will 

comply with applicable emission standards throughout the useful life.

(c) To compare emission levels with emission standards, apply deterioration factors to 

the measured emission levels. Establish an additive deterioration factor for the vehicle 

family, as described in 40 CFR 86.007-23(b).

(1) For vehicles at or below 26,000 pounds GVWR, establish the deterioration factor 

based on testing before and after service accumulation. Collect emission data using 

measurements to one more decimal place than the applicable standard. Use good 

engineering judgment to perform service accumulation in a way that incorporates the 

effects of ambient conditions and engine and vehicle operation to ensure that 

emission measurements represent actual degradation of emission controls from in-use 

vehicles over the useful life. 

(2) For vehicles above 26,000 pounds GVWR, establish the deterioration factor based 

on an engineering analysis that takes into account the expected aging from in-use 

vehicles. Your analysis must take into account your testing to establish deterioration 

factors under paragraph (c)(1) of this section.

(d) You may ask us to approve deterioration factors for a vehicle family based on 

emission measurements from similar highway vehicles if you have already given us these 

data for certifying the other vehicles in the same or earlier model years. Use good 

engineering judgment to decide whether the two vehicles are similar. We will approve 
your request if you show us that the emission measurements from other vehicles 

reasonably represent in-use deterioration for the vehicle family for which you have not 

yet determined deterioration factors.

(e) Apply the deterioration factor to the official emission result, as described in 

paragraph (c) of this section, then round the adjusted figure to the same number of 

decimal places as the emission standard. Compare the rounded emission levels to the 

emission standard for each emission-data vehicle. 

§ 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 transmission, axle ratio, and engine in addition to 

subfamily identifiersidentifier. Report uncertified vehicles sold to secondary vehicle 

manufacturers. Small manufacturers may omit the reporting requirements of this 

requirement.paragraph (a). 

(b) Organize and maintain the following records: 

(1) A copy of all applications and any summary information you send us. 

(2) Any of the information we specify in § 1037.205 that you were not required to 

include in your application. 

(3) A detailed history of each emission-data vehicle, if applicable. 

(4) Production figures for each vehicle family divided by assembly plant. 

(5) Keep a list of vehicle identification numbers for all the vehicles you produce 

under each certificate of conformity. 

(c) Keep routine data from routine emission tests required by this part (such as test cell 

temperatures and relative humidity readings) for one year after we issue the associated 

certificate of conformity. Keep all other information specified in this section for eight 

years after we issue your certificate. 

(d) Store these records in any format and on any media, as long as you can promptly send 

us organized, written records in English if we ask for them. You must keep these records 

readily available. We may review them at any time. 

§ 1037.255 What decisions may EPA make regarding my certificate of conformity? 

(a) If we determine your application is complete and shows that the vehicle family meets 

all the requirements of this part and the Act, we will issue a certificate of conformity for 

your vehicle family for that model year. We may make the approval subject to additional 

conditions. 

(b) We may deny your application for certification if we determine that your vehicle 

family fails to comply with emission standards or other requirements of this part or the 

Clean Air Act. We will base our decision on all available information. If we deny your 

application, we will explain why in writing. 

(c) In addition, we may deny your application or suspend or revoke your certificate if you 

do any of the following: 

(1) Refuse to comply with any testing or reporting requirements. 

(2) Submit false or incomplete information (paragraph (e) of this section applies if 
this is fraudulent). This includes doing anything after submission of your application 

to render any of the submitted information false or incomplete. 

(3) Render any test data inaccurate. 

(4) Deny us from completing authorized activities despite our presenting a warrant or 

court order (see 40 CFR 1068.20). This includes a failure to provide reasonable 

assistance. 

(5) Produce vehicles for importation into the United States at a location where local 

law prohibits us from carrying out authorized activities. 

 (6) Fail to supply requested information or amend your application to include all 

vehicles being produced. 

(7) Take any action that otherwise circumvents the intent of the Act or this part, with 

respect to your engine family. 

(d) We may void the certificate of conformity for a vehicle family if you fail to keep 

records, send reports, or give us information as required under this part or the Act. Note 

that these are also violations of §40 CFR 1068.101(a)(2). 

(e) We may void your certificate if we find that you intentionally submitted false or 

incomplete information. This includes rendering submitted information false or 

incomplete after submission. 

(f) If we deny your application or suspend, revoke, or void your certificate, you may ask 

for a hearing (see § 1037.820). 

Subpart D—[Reserved] 

Subpart E—In-use Testing 

§ 1037.401 General provisions. 

We may perform in-use testing of any vehicle subject to the standards of this part. For 

example, we may test vehicles to verify drag areas or other GEM inputs.

Subpart F—Test and Modeling Procedures 

§ 1037.501 General testing and modeling provisions. 

This subpart specifies how to perform emission testing and emission modeling required 

elsewhere in this part. 

(a) Use the equipment and procedures specified in 40 CFR part 86, subpart M, to 

determine whether vehicles meet the diurnal, running loss, hot soak, and spitback 

standards specified in § 1037.103. For certification vehicles only, you may ask us to 

approve subtraction of nonfuel emissions (such as from off-gassing plastic components) 

from your measured test results. In your request, describe the sources of nonfuel 

emissions and estimate the decay rate. Quantify the nonfuel emissions based on separate 

testing.

(a) [Reserved] 

(b) Where exhaust emission testing is required, use the equipment and procedures in 40 

CFR part 1066 to determine whether your vehicles meet the duty-cycle emission 

standards in subpart B of this part. Measure the emissions of all the exhaust constituents 

subject to emission standards as specified in 40 CFR part 1066. Use the applicable duty 
cycles specified in § 1037.510. 

(c) [Reserved] 

(d) Use the applicable fuels specified 40 CFR part 1065 to perform valid tests. 

(1) For service accumulation, use the test fuel or any commercially available fuel that 

is representative of the fuel that in-use vehicles will use. 

(2) For diesel-fueled vehicles, use the appropriate diesel fuel specified for emission 

testing. Unless we specify otherwise, the appropriate diesel test fuel is the ultra lowsulfur diesel fuel. 

(3) For gasoline-fueled vehicles, use the gasoline specified for “General Testing”. 

(e) You may use special or alternate procedures to the extent we allow them underas 

specified in 40 CFR 1065.10. 

(f) This subpart is addressed to you as a manufacturer, but it applies equally to anyone 

who does testing for you, and to us when we perform testing to determine if your vehicles 

meet emission standards. 

(g) Apply the specification of this paragraph (g) whenever we specify use of standard 

trailers. Unless otherwise specified, a tolerance of ±2 inches applies for all nominal 

trailer dimensions. Manufacturers may test with longer trailers. For coastdown testing,

load trailers as necessary to reach test weight.(

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

(i) It is aan unloaded two-axle dry van box trailer with dimensions of 53.0 feet 

long, by 102 inches wide, byand 162 inches high (measured from the ground with 

the trailer level). 

(ii) It has a king pin located with its center 36±0.5 inches from the front of the 

trailer and a minimized trailer gap (maximum ofno greater than 45 inches). 

(iii) It has a smooth surface with nominally flush rivets and does not include any 

aerodynamic features such as side fairings, boat tails, or gap reducers. It may 

have a scuff band protrudingof no more than 0.13 inches in thickness. 

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

gear. The centerline of the rear-most axle must be 144146 inches from the rear of 

the trailer. 

(2) The standard trailer for mid-roof tractors is aan empty two-axle tanker trailer with 

dimensions of 40.0 42±1 feet long by 124140 inches high, and having . 

(i) It has a 40±1 feet long cylindrical tank with a 72000±7 gallon tank capacity. , 

smooth surface, and rounded ends. 

(ii) The standard tanker trailer does not include any aerodynamic features such as 

side fairings, but does include a centered 20 inch manhole, side-centered ladder, 

and lengthwise walkway. It includes dual 24.5 inch wheels. 

(3) The standard trailer for low-roof tractors is aan unloaded two-axle flat bed trailer 

with dimensions of 48.0 53±1 feet long and 102 inches wide. 

(i) The deck height is 60.0±0.5 inches in the front and 55.0±0.5 inches in the rear.

The standard trailer does not include any aerodynamic features such as side 

fairings. It includes a payload of dense material (such as steel plate). For 

aerodynamic modeling, use an amount equivalent

(ii) It includes an air suspension and dual 22.5 inch wheels on tandem axles 

spread up to a standard payload of 25,000 pounds for Class 7 and 38,000 pounds 

for Class 8.122 inches apart between axle centerlines, measured along the length 
of the trailer. 

§ 1037.510 Duty-cycle exhaust testing. 

This section applies where exhaust emission testing is required, such as when applying 

the provisions of § 1037.610615. Note that for most vehicles, testing under this section is 

not required. 

(a) Where applicable, measure emissions by testing the vehicle on a chassis dynamometer 

with the applicable test cycles. Each test cycle consists of a series of speed commands 

over time: variable speeds for the transient test and constant speeds for the cruise tests. 

None of these cycles include vehicle starting or warmup; each test cycle begins with a 

running, warmed-up vehicle. Start sampling emissions at the start of each cycle. The 

transient cycle is specified in Appendix I to this part. For the 55 mph and 65 mph cruise 

cycles are, sample emissions for 300 second cycles with constant vehicle speeds of 55.0 

mph and 65.0 mph, respectively. The tolerance around these speed setpoints is ±1.0 mph. 

(b) Calculate the official emission result from the following weighting factorsequation: 

55 55 65 65

55 65

1

( )

transient transient

transient

g w m w m w m Emissions

ton mile payload tons D D D

    ⋅ ⋅ ⋅   = ⋅ + +     −  

Where: 

payload = the standard payload, in tons, as specified in §1037.705.

w = weighting factor for the appropriate test cycle, as described in paragraph (c) of this 

section.

m = grams of CO2 emitted over the appropriate test cycle.

D = miles driven over the appropriate test cycle.

(c) Apply weighting factors specific to each type of vehicle and for each duty cycle as 

described in the following table:

Table 1 to § 1037.510—Weighting Factors for Duty Cycles 

Transient 55 mph Cruise 65 mph Cruise 

Vocational 42% 21% 37% 

Vocational 

HybridsHybrid 

Vehicles

75% 9% 16% 

Day Cabs 19% 17% 64% 

Sleeper Cabs 5% 9% 86% 

(cd) For transient testing, compare actual second-by-second vehicle speed with the speed 

specified in the test cycle and ensure any differences are consistent with the criteria as 

specified in 40 CFR part 1066. If the speeds do not conform to these criteria, the test is 

not valid and must be repeated. 

(de) Run test cycles as specified in 40 CFR part 86. For cruise cycle testing of vehicles 

equipped with cruise control, use the vehicle’s cruise control to control the vehicle speed. 

For vehicles equipped with adjustable VSLs, test the vehicle with the VSL at its highest 

setting.

Formatted Table

Deleted Cells
(ef) Test the vehicle using its adjusted loaded vehicle weight, unless we determine this 

would be unrepresentative of in-use operation (as specified in 40 CFR 1065.10(c)(1)).).

(g) For hybrid vehicles, correct for the net energy change of the energy storage device as 

described in 40 CFR 1066.501.

§ 1037.520 Modeling CO2 emissions to show compliance. 

This section describes how to use the GEM computer modelsimulation 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 model. 

(a) General modeling provisions. To run the GEM model, enter all applicable inputs as 

specified by the model. All seven of the following inputs apply for sleeper cab tractors, 

while some do not apply for other regulatory subcategories: 

(1) Regulatory subcategory (such as “Class 8 Combination – Sleeper Cab – High 

Roof”). 

(2) Coefficient of aerodynamic drag, as described in paragraph (b) of this section. 

Leave this field blank for vocational vehicles. 

(3) Steer tire rolling resistance, as described in paragraph (c) of this section. 

(4) Drive tire rolling resistance, as described in paragraph (c) of this section. 

(5) Vehicle speed limit, as described in paragraph (d) of this section. Leave this field 

blank for vocational vehicles. 

(6) Vehicle weight reduction, as described in paragraph (e) of this section. Leave this 

field blank for vocational vehicles. 

(7) Extended idle reduction credit, as described in paragraph (f) of this section. Leave 

this field blank for vehicles other than Class 8 sleeper cabs. 

(b) Coefficient of aerodynamic drag and drag area. Determine the appropriate drag area 

as follows: 

(1) Use the recommended method or an alternate method to establish a value for the 

vehicle’s dragarea, drag area, expressed in m2 and rounded to two decimal places. 

Assume a standard trailer for high roof tractors and no trailer for other vehicles. as 

follows:

(i) Recommended method. Perform coastdown testing as described in this 

paragraph (b)(1)(i) Where we allow you to establishgroup multiple 

configurations together, measure the drag coefficient. Usearea of the 

proceduresworst-case configuration. Measure drag areas specified in 40 CFR part 

1066, subpart C, with a standard trailer. 

(A) Calculate the drag area (CDA) in m2, from the following equation:

-./ 

.

12

Where:

CD = drag coefficient.

A = frontal area of vehicle, in m2.

D = a coefficient derived from the coastdown procedures in 40 CFR part 

1066, as described in paragraph (b)(1)(i)(B) of this section.
ρ = standard air density. Use ρ =1.167 kg/m3

. 

(B) Determine the value of D analytically from the data collected during 

coastdown testing as specified in 40 CFR 1066.310, based on one of the 

following equations:

2 2 2

e m r r

dS M A DS ES Y

dt

− = + + 

or 

2

e m r

dS M A DS

dt

− = +

(ii) Alternate methods. You may determine a drag coefficient using an alternate 

method, consistent with good engineering judgment, based on wind tunnel

testing, computational fluid dynamic modeling, or constant-speed road load 

testing as described in §1037.521. 

(2) Determine the bin categorylevel for your vehicle based on the drag area from 

paragraph (b)(1) of this section as shown in the following tables: 
High-Roof Day Cabs 

Bin Level If your measured CDA (m2) 

is . . . 

Then your CD input is . . . 

Bin I ≥ 7.98.0 0.7879

Bin II 67.1-7.9-7.8 0.7072

Bin III 5.9-6.82-7.0 0.6263

Bin IV 5.4-5.86-6.1 0.5456

Bin V ≤ 5.35 0.5051

High-Roof Sleeper Cabs 

Bin Level If your measured CDA (m2) 

is . . . 

Then your CD input is . . . 

Bin I ≥ 7.56 0.7475

Bin II 6.7-7.5-7.4 0.6668

Bin III 5.58-6.46 0.5860

Bin IV 5.02-5.47 0.5052

Bin V ≤ 4.95.1 0.4647

Low-Roof Day and Sleeper Cabs 

Bin Level If your measured CDA (m2) 

is . . . 

Then your CD input is . . . 

Bin I ≥ 5.1 0.77 

Bin II ≤ 5.0 0.71 

Mid-Roof Day and Sleeper Cabs 

Bin Level If your measured CDA (m2) 

is . . . 

Then your CD input is . . . 

Bin I ≥ 5.6.5 0.87 

Bin II ≤ 6.45.5 0.82 

(3) For low- and mid-roof tractors, you may determine your drag area bin based on 

the drag area bin of an equivalent high-roof tractor. If the high-roof tractor is in Bin 

1I or Bin 2II, then you may assume your equivalent low- and mid-roof tractors are in 

Bin 1I. If the high-roof tractor is in Bin 3III, Bin 4IV, or Bin 5V, then you may 

assume your equivalent low- and mid-roof tractors are in Bin 2II. 

(c) Steer and drive tire rolling resistance. You must have a tire rolling resistance level 

(TRRL) for each tire configuration. For purposes of this section, you may consider tires 

with the same SKU number to be the same configuration.

(1) Measure tire rolling resistance in kg per metric ton as specified in ISO test method 

28580 (incorporated by reference in § 1037.810). ), except as specified in this 

paragraph (c). Use good engineering judgment to ensure that your test results are not 

biased low. You may ask us to identify a reference test laboratory to which you may 

correlate your test results. Prior to beginning the test procedure in Section 7 of ISO 

28580 for a new bias-ply tire, perform a break-in procedure by running the tire at the 

specified test speed, load, and pressure for 60±2 minutes.

(2) For each tire design (including size),tested, measure rolling resistance of at least 

three different tires of that specific design and size. Perform the test at least three 

timesonce for each tire (for a total of at least nine tests per tire design).. Use the 
arithmetic mean of these results. as your test result. You may use this value as your 

GEM input or select a higher TRRL. You must test at least one tire size for each tire 

model, and may use engineering analysis to determine the rolling resistance of other 

tire sizes of that model. Note that for tire sizes that you do not test, we will treat your 

analytically derived rolling resistances the same as test results, and we may perform 

our own testing to verify your values. We may require you to test a small sub-sample 

of untested tire sizes that we select.

(3) If you obtain your test results from the tire manufacturer or another third party, 

you must obtain a signed statement from them verifying the tests were conducted 

according to the requirements of this part. Such statements are deemed to be 

submissions to EPA.

(4) For tires marketed as light truck tires (and that is, tires having tire codes that begin 

with “LT”),have load ranges C, D, or E, use as the GEM input an adjusted rolling 

resistance equal toTRRL at or above the measured rolling resistance multiplied by 

0.87. 

(d) Vehicle speed limit. If the vehicles will be equipped with a vehicle speed limiter, 

input the maximum vehicle speed to which the vehicle will be limited (in miles per hour

rounded to the nearest 0.1 mile per hour) as specified in §1037.640. Otherwise leave this 

field blank. Use good engineering judgment to ensure the limiter is tamper resistant. We 

may require you to obtain preliminary approval for your designs. 

(e) Vehicle weight reduction. For purposes of this paragraph (e), high-strength steel is

steel with tensile strength at or above 270 MPa. 

(1) Vehicle weight reduction inputs for wheels are specified relative to dual-wide tires 

with conventional steel wheels. For purposes of this paragraph (e)(1), a light-weight 

aluminum wheel is one that weighs at least 21 lb less than a comparable conventional 

steel wheel, and a high-strength steel wheel is one that weighs at least 8 lb less than a 

comparable conventional steel wheel.. The inputs are listed in Table 4 to this section. 

For example, a tractor with aluminum steer wheels and eight (4×2) dual-wide 

aluminum drive wheels would have an input of 210 lb (2×21 + 8×21). 

Table 4 to § 1037.520—Wheel-Related Weight Reductions 

Weight Reduction Technology Weight Reduction 

(lb per tire or wheel) 

Single-Wide Drive Tire with . . . Steel Wheel 84 

Aluminum Wheel 139 

Light-Weight Aluminum Wheel 147 

Steer Tire or Dual-wide Drive 

Tire with . . . 

High-Strength Steel Wheel 8 

Aluminum Wheel 21 

Light-Weight Aluminum Wheel 30 

(2) Vehicle weight reduction inputs for components other than wheels are specified 

relative to mild steel components. The inputs are listed in Table 5 to this section. as 

specified in the following table: 
Table 5 to § 1037.520—Nonwheel-Related Weight Reductions 

Weight Reduction Technologies Aluminum Weight 

Reduction (lb.))

High-Strength Steel 

Weight Reduction (lb.))

Door 20 6 

Roof 60 18 

Cab rear wall 49 16 

Cab floor 56 18 

Hood Support Structure System 15 3 

Fairing Support Structure System 35 6 

Instrument Panel Support Structure 5 1 

Brake Drums – Drive (4) 140 11 

Brake Drums – Non Drive (2) 60 8 

Frame Rails 440 87 

Crossmember - Cab 15 5 

Crossmember – Suspension 25 6 

Crossmember – Non Suspension (3) 15 5 

Fifth Wheel 100 25 

Radiator Support 20 6 

Fan Shroud 10 2

Fuel Tank Support Structure 40 12 

Steps 35 6 

Bumper 33 10 

Shackles 10 3 

Front Axle 60 15 

Suspension Brackets, Hangers 100 30 

Transmission Case 50 12 

Clutch Housing 40 10 

Drive Axle Hubs (8) 160 4 

Non Drive Front Hubs (2) 40 5 

Driveshaft 20 5 

Transmission/Clutch Shift Levers 20 4 

(3) You may ask to apply the innovative technology provisions of §1037.610 for 

weight reductions not covered by this paragraph (e).

(f) Extended idle reduction credit. If your tractor is equipped with idle reduction 

technology meeting the requirements of §1037.660 that will automatically shut off the 

main engine after 300 seconds or less, use 5.0 g/ton-mile as the input (or a lesser value 

specified in §1037.660).Otherwise leave this field blank. 

§1037.521 Aerodynamic measurements. 

This section describes how to measuredetermine the aerodynamic drag area (CDA) of 

your vehicle using an alternative method correlated to the coastdown procedure in 40 

CFR part 10651066 or an alternative method correlated to it. 

(a) General. The primary method for measuring the aerodynamic drag area of vehicles is 

specified in §0137.520paragraph (b) and 40 CFR 1065.210.of this section. You may 

determine athe drag coefficientarea using an alternate method, consistent with the 
provisions of this section and good engineering judgment, based on wind tunnel testing, 

computational fluid dynamic modeling, or constant-speed road load testing. (See 40 CFR 

1068.5 for provisions describing how we may evaluate your engineering judgment.) 

(1). All drag areas measured using an alternative method (CDAalt) must be adjusted to be 

equivalent to the corresponding drag areas that would have been measured using the 

coastdown procedure specified under this part.as follows: 

(1) Unless good engineering judgment requires otherwise, assume that coastdown 

drag areas are proportional to drag areas measured using alternative methods. This 

means you may apply a single constant adjustment factor (Falt-aero) for a given 

alternate drag area method using the following equation: 

CDA = CDAalt × Falt-aero

(i) Unless good engineering judgment requires otherwise, assume that coastdown 

drag areas are proportional to drag areas measured using alternative methods. 

This means you may use a single constant adjustment factor (Falt-aero) for a given 

alternate drag area method.

(ii2) Determine the adjustment factorFalt-aero by performing coastdown testing and 

applying your alternate method on the same vehicle. Unless we approve another 

vehicle, the vehicle must be a Class 8, high-roof, sleeper cab with a full aerodynamics 

package, pulling a standards trailer. Where you have more than one model meeting 

these criteria, use the model with the highest projected sales. If you do not have such 

a model, you may use ayour most comparable model. with prior approval. If good 

engineering judgment allows the use of a single, constant value of Falt-aero, calculate it 

from this coastdown drag area (CDAcoast) divided by alternative drag area (CDAalt):

(iii Falt-aero = CDAcoast ÷ CDAalt

(3) Calculate you adjustment factorFalt-aero to at least three decimal places. For 

example, if your coastdown testing results in a drag area of 6.430, but your wind 

tunnel method results in a drag area of 6.200, your adjustment factorFalt-aero would be 

1.037. 

(b) Approval.(b) Recommended method. Perform coastdown testing as described in 40 

CFR part 1066, subpart D, subject to the following additional provisions:

(1) The specifications of this paragraph (b)(1) apply when measuring drag areas for 

tractors. Test high-roof tractors with a standard box trailer. Test low- and mid-roof 

tractors without a trailer (sometimes referred to as in a “bobtail configuration”). You 

may test low- and mid-roof tractors with a trailer to evaluate innovative technologies.

(2) The specifications of this paragraph (b)(2) apply for tractors and standard trailers. 

Use tires mounted on steel rims in a dual configuration (except for steer tires). The 

tires must–

(i) Be SmartWay-Verified tires or have a rolling resistance below 5.1 kg/ton.

(ii) Have accumulated at least 2,175 miles of prior use but have no less than 50

percent of their original tread depth (as specified for truck cabs in SAE J1263).

(iii) Not be retreads or have any apparent signs of chunking or uneven wear.

(iv) Be size 295/75R22.5 or 275/80R22.5.

(3) Calculate the drag area (CDA) in m2 from the coastdown procedure specified in 40 

CFR part 1066.
(c) Approval. You must obtain preliminary approval before using any methods other 

than coastdown testing to determine drag coefficients. Send the Designated Compliance 

Officer your request.Send your request for approval to the Designated Compliance 

Officer. Keep records of the information specified in this paragraph (c). Unless we 

specify otherwise, include this information with your request. You must provide any 

information we require to evaluate whether you are apply the provisions of this section 

consistent with good engineering judgment. 

(1) Includinge all of the following for your coastdown results: 

(i) The name, location, and description of your test facilities. Include the 

following in your description:

(A), including background/history.

(B), equipment and capability.

(C), and track and facility elevation, along with the grade and size/length of the 

track. 

(ii) Test conditions for each test result, including date and time, wind speed and 

direction, ambient temperature and humidity, vehicle speed, driving distance, 

manufacturer name, test vehicle/model type, model year, applicable model engine 

family, tire type and rolling resistance, test weight of tractor-trailer (as tested),

and driver name(s) and/or IDidentifier(s). 

(iii) Average Cddrag area result as calculated in §1037.520(b) from at least ten 

valid tests, standard deviation, calculated error40 CFR 1066, subpart D) and error 

bands, and total number of tests, all of the individual run results (including 

number of voided or invalid tests.runs). 

(2) Including allIdentify the name and location of the followingtest facilities for your 

wind tunnel method (if applicable):). Also include the following things to describe 

the test facility:

 (i) The name, location, and description of your test facilities. Include the 

following in your description:

(A) Background/history. 

(Bii) The layout (with diagram), type, and, construction (structural and material) 

of the wind tunnel.

(Ciii) Wind tunnel design details: corner turning vane type and material, air 

settling, mesh screen specification, air straightening method, tunnel volume, 

surface area, average duct area, and circuit length. 

(Div) Wind tunnel flow quality: temperature control and uniformity, airflow 

quality, minimum airflow velocity, flow uniformity, angularity and stability, static 

pressure variation, turbulence intensity, airflow acceleration and deceleration 

times, test duration flow quality, and overall airflow quality achievement. 

(Ev) Test/working section information: test section type (e.g., open, closed, 

adaptive wall) and shape (e.g., circular, square, oval), length, contraction ratio, 

maximum air velocity, maximum dynamic pressure, nozzle width and height, 

plenum dimensions and net volume, maximum allowed model scale, maximum 

model height above road, strut movement rate (if applicable), model support, 

primary boundary layer slot, boundary layer elimination method, and photos and 

diagrams of the test section. 
(Fvi) Fan section description: fan type, diameter, power, maximum rotational 

speed, maximum top speed, support type, mechanical drive, and sectional total 

weight.

(Gvii) Data acquisition and control (where applicable): acquisition type, motor 

control, tunnel control, model balance, model pressure measurement, wheel drag 

balances, wing/body panel balances, and model exhaust simulation.

(Hviii) Moving ground plane or rolling road (if applicable): construction and 

material, yaw table and range, moving ground length and width, belt type, 

maximum belt speed, belt suction mechanism, platen instrumentation, 

temperature control, and steering. 

(Iix) Facility correction factors and purpose. 

(c3) Include all of the following for your computational fluid dynamics (CFD) 

method (if applicable):

(i) Official name/title of the software product.

(ii) Date and version number for the software product.

(iii) Manufacturer/company name, address, phone number and web address for 

software product.

(iv) Identify if the software code is Navier-Stokes or Lattice-Boltzmann based.

(4) Include all of the following for any other method (if applicable):

(i) Official name/title of the procedure(s).

(ii) Description of the procedure.

(iii) Cited sources for any standardized procedures that the method is based on.

(iv) Modifications/deviations from the standardized procedures for the method 

and rational for modifications/deviations.

(v) Data comparing this requested procedure to the coastdown reference 

procedure.

(vi) Information above from the other methods as applicable to this method (e.g., 

source location/address, background/history).

(d) Wind tunnel methods. (1) You may measure drag areas consistent with the modified 

SAE procedures described in the paragraph (d) using any wind tunnel recognized by the 

Subsonic Aerodynamic Testing Association, consistent with . If your wind tunnel is not 

capable of testing in accordance with these modified SAE procedures, you may ask us to 

approve your alternate test procedures if you demonstrate that your procedures produce 

equivalent data. For purposes of this paragraph (d), data are equivalent if they are the 

same or better with respect to repeatability and unbiased correlation with coastdown 

testing. Note that, for wind tunnels not capable of these modified SAE procedures, good 

engineering judgment and the following modified SAE procedures:

(1) may require you to base your alternate method adjustment factor on more than one 

vehicle. You may not develop your correction factor until we have approved your 

alternate method. The applicable SAE procedures are SAE J1252, “SAE WIND 

TUNNEL TEST PROCEDURE FOR TRUCKS AND BUSES” (July 1981) except 

that article 5.2 that specifies a minimum Reynolds number of 0.7 x 106 is not 

included and is superseded, for the purposes of this rulemaking, by a minimum 

Reynolds number of 1.0 x 106 and,SAE J1594, and SAE J2071(incorporated by 

reference in §1037.810). The following modifications apply for SAE J1252: 
(i) The minimum Reynold's number (Remin) is 1.0 x 106

 instead of the value 

specified in section 5.2 of the SAE procedure. Your model frontal area at zero 

yaw angle may exceed the recommended 5 percent of the active test section area, 

provided it does not exceed 25 percent.

(ii) For full-scale wind tunnel testing, use good engineering judgment to select a 

test article (tractor and trailer) that is a reasonable representation of the test article 

used for the reference method testing. For example, where your wind tunnel is 

not long enough to test the tractor with a standard 53 foot trailer, it may be 

appropriate to use shorter box trailer. In such a case, the correlation developed 

using the shorter trailer would only be valid for testing with the shorter trailer.

(iii) For reduced-scale wind tunnel testing, a one-eighth (1/8th) or larger scale 

model of a heavy-duty tractor and trailer must be used, and the model must be of 

sufficient design to simulate airflow through the radiator inlet grill and across an 

engine geometry representative of those commonly used in your test vehicle. 

(2) J1594, “VEHICLE AERODYNAMICS TERMINOLOGY” (December 1994).

(3) J2071, “AERODYNAMIC TESTING OF ROAD VEHICLES - OPEN 

THROAT WIND TUNNEL ADJUSTMENT” (June 1994).

For wind tunnel testing, we are finalizing that manufacturersYou must perform wind 

tunnel testing and the coastdown procedure, according the requirements final in this 

notice, on the same tractor model and provide the results for both methods. Conduct

the wind tunnel tests should be conducted at a zero yaw angle and, if so equipped, 

utilizing the moving/rolling floor (i.e., the moving/rolling floor should be on during 

the test, as opposed to static) for comparison to the coastdown procedure, which 

corrects to a zero yaw angle for the oncoming wind. 

(de) Computational fluid dynamics (CFD). You may measuredetermine drag areas using 

a CFD method, consistent with good engineering judgment and the requirements of this 

paragraph. You must use (e) using commercially -available CFD software code with a 

turbulence model and Navier-Stokes formula solver, where applicable. Conduct the 

analysis assuming zero yaw angle, and ambient conditions consistent with coastdown 

procedures. For simulating a wind tunnel test, the analysis should accurately model 

thatthe particular wind tunnel and assume a wind tunnel blockage ratio consistent with 

SAE J1252 or(incorporated by reference in §1037.810) or one that matches the selected 

wind tunnel, whichever is lower. For simulation of open road conditions similar to that 

experienced during coastdown test procedures, the CFD analysis should assume a 

blockage ratio of less thanat or equalbelow 0.2%. percent. 

(1) For Navier-Stokes basedTake the following steps for CFD code, with a NavierStokes formula solver:

(i) Perform an unstructured, time-accurate, analysis withusing a mesh grid size 

with total surface elementsvolume element count of between one hundred and 

twenty million and one hundred and fiftyat least 50 million cells using hexagonal 

of hexahedral and/or polyhedral mesh cell shapes, a cell size of shape, surface 

elements representing the geometry consisting of no less than or equal to 1 mm on 

the vehicle surface6 million elements, and a surrounding volume element size in 

millimeters extending to the outer boundary of the volume as described by the 

equation; integer of 2 to the power of n where n equals the distance away from 

the vehicle surface (e.g., the cell size at 0.1mm (n) away from the surface would 
be 1mm [2 to the power of 0.1mm equals 1.07; the integer of 1.07 equals 1]).nearwall cell size corresponding to a y+ value of less than 300, with the smallest cell 

sizes applied to local regions of the tractor and trailer in areas of high flow 

gradients and smaller geometry features. 

(ii) Perform the analysis with a k-epsilon (k-ε) or a shear stress transport k-omega 

(SST k-ω) turbulence model and mesh deformation enabled (if applicable) with 

boundary layer resolution of +/- ±95%. (2) percent. Once result convergence is 

achieved, demonstrate the convergence by supplying multiple, successive 

convergence values for the analysis. The turbulence model may use k-epsilon (kε), shear stress transport k-omega (SST k-ω), or other commercially accepted 

methods.

(2) For Lattice-Boltzman based CFD code, perform an unstructured, time-accurate 

analysis withusing a mesh grid size with total surface elements of between one 

hundred and twenty million and one hundred and fifty at least 50 million cells using 

cubic volume elements and triangulear and/or quadrilateral surface elements, with a 

near wall cell size of lessno greater than or equal to 16 mm on local regions of the 

vehicle surface,tractor and a surrounding volume element size measuredtrailer in 

millimeters and extending to the outer boundaryareas of the volume as described by 

the equation: integer of 2 to the power of n where n equals the distance awayhigh 

flow gradients and smaller geometry features, with cell sizes in other areas of the 

mesh grid starting at twelve millimeters and increasing in size from this value as the 

distance from the tractor-trailer model increases. 

(3) All CFD analysis should be conducted using the following conditions: 

(i) A tractor-trailer combination using the manufacturer’s tractor and the standard 

trailer, as applicable.

(ii) An environment with a blockage ratio at or below 0.2 percent to simulate open 

road conditions, a zero degree yaw angle between the oncoming wind and the 

tractor-trailer combination.

(iii) Ambient conditions consistent with the coastdown test procedures specified 

in this part.

(iv) Open grill with representative back pressures based on data from the vehicle 

surface (e.g., the cell size at 0.1mm (n) away from the surface would be 1mm 

since 2 to the power of 0.1mm equals 1.07tractor model,

(v) Turbulence model and the integermesh deformation enabled (if applicable). 

(vi) Tires and ground plane in motion consistent with and simulating a vehicle 

moving in the forward direction of travel.

(vii) The smallest cell size should be applied to local regions on the tractor and 

trailer in areas of high flow gradients and smaller geometry features (e.g., the apillar, mirror, visor, grille and accessories, trailer leading and trailing edges, rear 

bogey, tires, and tractor-trailer gap).

(viii) Simulate a speed of 1.07 equals 1).55 mph.

(4) You may ask us to allow you to perform CFD analysis using parameters and 

criteria other than those specified in this paragraph (e), consistent with good 

engineering judgment, if you can demonstrate that the specified conditions are not 

feasible (e.g., insufficient computing power to conduct such analysis, inordinate 

length of time to conduct analysis, equivalent flow characteristics with more feasible 
criteria/parameters) or improved criteria may yield better results (e.g., different mesh 

cell shape and size). To support this request, we may require that you supply data 

demonstrating that your selected parameters/criteria will provide a sufficient level of 

detail to yield an accurate analysis, including comparison of key characteristics 

between your criteria/parameters and the criteria specified in paragraphs (e)(1) and 

(2) of this section (e.g., pressure profiles, drag build-up, and/or turbulent/laminar flow 

at key points on the front of the tractor and/or over the length of the tractor-trailer 

combination).

(f) Yaw sweep corrections. You may optionally apply this paragraph (f) for vehicles with 

aerodynamic features that are more effective at reducing wind-averaged drag than is 

predicted by zero-yaw drag. You may correct your zero-yaw drag area as follows if the 

ratio of the zero-yaw drag area divided by yaw sweep drag area for your vehicle is greater

than 0.8065 (which represents the ratio expected for a typical aerodynamic Class 8 highroof sleeper cab tractor):

(1) Determine the zero-yaw drag area and the yaw sweep drag area for your vehicle 

using the same alternate method as specified in this subpart. Measure drag area for 

0°, -6°, and +6°. Use the arithmetic mean of the -6° and +6° drag areas as the ±6°

drag area.

(2) Calculate your yaw sweep correction factor (CFys) using the following equation:

-345 

67° .9:; /9<: = >. ?>7@

A<9B C:D .9:; /9<:

(3) Calculate your corrected drag area for determining the aerodynamic bin by 

multiplying the measured zero-yaw drag area by CFys. The correction factor may be 

applied to drag areas measured using other procedures. For example, we would apply 

CFys to drag areas measured using the recommended coastdown method. If you use 

an alternative method, you would also need to apply an alternative correction (Falt-aero) 

and calculate the final drag area using the following equation:

 CDA = Falt-aero · CFys · (CDA)zero-alt

(4) You may ask us to apply CFys to similar vehicles incorporating the same design 

features.

(5) As an alternative, you may choose to calculate the wind-averaged drag area 

according to SAE J1252 (incorporated by reference in §1037.810) and substitute this 

value into the equation in paragraph (f)(2) of this section for the ±6° yaw-averaged 

drag area.

§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. 

You may ask us to modify the provisions of this section to allow testing non-electric 

hybrid vehicles The procedures are written to test the PTO 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 whole vehicles or with a posttransmission hybrid system. When testing just the post-transmission hybrid system, you 
must include all hardware for the PTO system. You may ask us to modify the provisions 

of this section to allow testing hybrid vehicles other than electric-battery hybrids, 

consistent with good engineering judgment. 

(a) Select two vehicles for testing as follows: 

(1) Select a vehicle with a hybrid powertrain to represent the vehicle family. If your 

vehicle family includes more than one vehicle model, use good engineering judgment 

to select the vehicle type with the maximum number of PTO circuits that has the 

smallest potential reduction in greenhouse gas emissions. 

(2) Select an equivalent conventional vehicle as specified in §1037.610615. 

(b) Measure PTO emissions from the fully warmed-up conventional vehicle as follows: 

(1) Start the engine.

((1) Without adding any additional restrictions, instrument the vehicle with pressure 

transducers at the outlet of the hydraulic pump for each circuit.

(2) Operate the vehicle PTO system with no load for at least 15 seconds. Measure the 

pressure and record the average value over the last 10 seconds (pmin). Apply 

maximum operator demand to the PTO system until the pressure relief valve opens 

and pressure stabilizes; measure the pressue and record the average value over the last 

10 seconds (pmax). 

(3) Denormalize the PTO duty cycle(s) specified in Appendix II of this part. If there 

is only one PTO circuit, use duty using the following equation: 

( ) refi i max min min p NP p p p = ⋅ − + 

Where:

prefi = the reference pressure at each point i in the PTO cycle #1; if there are.

NPi= the normalized pressure at each point i in the PTO cycle.

pmax= the maximum pressure measured in paragraph (b)(2) of this section.

pmin= the minimum pressure measured in paragraph (b)(2) of this section.

(4) If the PTO system has two PTO circuits, userepeat paragraph (b)(2) and (3) of this 

section for the second PTO circuit.

(5) Install a system to control pressures in the PTO system during the cycle.

(6) Start the engine.

(7) Operate the vehicle over one or both specifiedof the denormalized PTO duty 

cycles, as applicable. Collect CO2 emissions during operation over the specifiedeach

duty cycle(s)..

(38) Use the provisions of 40 CFR part 1066 to collect and measure emissions. 

Calculate emission rates in grams per test without rounding. 

(49) For each test, validate the pressure in each circuit with the pressure specified 

from the cycle according to §40 CFR 1065.514 and using the table below. If test does 

not. Measured pressures must meet the requirementsspecifications in Table 1 of 

§1037.525 the test is void and needs to be repeated.the following table for a valid test:
Table 1 of §1037.525 – Default Statistical criteria for validating duty cycles 

Parameter Pressure

Slope, a1 0.830950 < a1 < 1.030

Absolute value of intercept, |a0| < 2.0 % of maximum mapped pressure

Standard error of estimate, SEE < 10 % of maximum mapped pressure

Coefficient of determination, r

2

> 0.850970

(510) Continue testing over the three vehicle drive cycles, as otherwise required by 

this part. 

(611) Calculate combined cycle-weighted emissions of the four cycles as specified in 

paragraph (d) of this section. 

(c) Measure PTO emissions from the fully warmed-up hybrid vehicle as follows: 

(1(1) Perform the steps in paragraphs (b)(1) through (5) of this section.

(2) Prepare the vehicle for testing by operating it as needed to stabilize the battery at a 

full state of charge. For battery electric hybridshybrid vehicles, we recommend 

running back-to-back PTO tests until engine operation is initiated to charge the 

battery. The battery should be fully charged once engine operation stops, provided

that. The ignition is left should remain in the “on”.” position. 

(3) Turn “off”the vehicle and PTO system off while the sampling system is being 

prepared. 

(24) Turn the vehicle “and PTO system on” such that the PTO system is functional, 

whether it draws power from the engine or a battery. 

(35) Operate the vehicle over the PTO cycle(s) without turning the vehicle “off”,,

until the engine turns “on”. Once engine is “on”, stop the PTO cycle, but continue to 

leave the vehicle and PTO system “on” until the engine turns off againstarts and then

shuts down. The test cycle is completed once the engine turns off.shuts down. 

Measure emissions as described in paragraphs (b)(2) and (3) of this section. Use 

good engineering judgment to minimize the variability in testing between the two 

types of vehicles. 

(46) Refer to paragraph (d)(4b)(9) of this section for cycle validation.(5.

(7) Continue testing over the three vehicle drive cycles, as otherwise required by this 

part. 

(68) Calculate combined cycle-weighted emissions of the four cycles as specified in 

paragraph (d) of this section. 

(d) Calculate combined cycle-weighted emissions of the four cycles for vocational 

vehicles as follows: 

(1) Calculate the g/ton-mile emission rate for the driving portion of the test 

as:specified in §1037.510.

*


 E

F

GHIJKLM N 

O

PQMHRGHI

= E

S.TUKV

.WX KLM 



S.SYKZ

X.UW KLM 



S.O[K\

U.XO KLM N Eq. 1037.525-1

 

Where:
payload = the standard payload, in tons, as specified in §1037.705.

m1 = grams of CO2 emitted over the transient test cycle.

m2 = grams of CO2 emitted over the 55 mph cruise test cycle.

m3 = grams of CO2 emitted over the 65 mph cruise test cycle.

(2) Calculate the g/hr emission rate for the PTO portion of the test by dividing the 

total mass emitted over the cycle (grams) by the time of the test (hours). For a testing 

where fractions of a cycle arewere run (for example, where an engine completes three 

cycles are completed and reaches the halfway point of a fourth PTO cycle is reached

before the engine turns on to recharge the systemstarts and shuts down again), use the 

following procedures to calculate the time of the test.: 

(i) Add up the time run for all complete tests.

(ii) For fractions of a test, use the following equation to calculate the time.:

( )

( )

circuit_1,i circuit_2,i

1

cycle

circuit_1,i circuit_2,i

1

N

i

test N

i

NP NP t

t t

NP NP t

=

=

⋅ ⋅∆

= ⋅

⋅ ⋅∆

∑

∑

Eq. §1037.525-2

( )

( )

fraction

cycle

circuit_1 circuit_2

1

2_circuits cycle

circuit_1 circuit_2

1

n t

n

n t

n

NP NP t

t t

NP NP t

=

=

=

=

⋅ ⋅∆

= ⋅

⋅ ⋅∆

∑

∑

Eq. §1037.525-3

Where: 

t1_circuitttest = time of the incomplete test with only one PTO circuit. 

t2_circuit = time of the incomplete test with two PTO circuits.

tcycle = time of a complete cycle.

i = the number of each measurement interval.

N = the total number of measurement intervals.

NPcircuit_1 = Normalized pressure command from circuit 1 of the PTO cycle. 

NPcircuit_2 = Normalized pressure command from circuit 2 of the PTO cycle. Let 

NPcircuit_2=1 if there is only one circuit.
tcycle = time of a complete cycle.

(iii) Sum the time from complete cycles (paragraph (d)(2)(i) of this section) and 

from partial cycles (paragraph (d)(2)(ii) of this section). 

(3) Convert the g/hr PTO result to an equivalent g/mi value based on the assumed 

fraction of engine operating time during which the PTO is operating (28%) percent)

and an assumed average vehicle speed while driving (27.1 mph). The conversion 

factor is: Factor = (0.280)/(1.000-0.280)/(27.1 mph) = 0.0144 hr/mi. Multiply the 

g/hr emission rate by 0.0144 hr/mi. 

(4) Divide the g/mi PTO emission rate by the standard payload and add this value to 

the g/ton-mile emission rate for the driving portion of the test. 

(e) Follow the provisions of §1037.610615 to calculate improvement factors and benefits 

for advanced technologies. 

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

This section describes the procedure for simulating a chassis test with a post-transmission 

hybrid system for A to B testing. The hardware that must be included in these tests is the 

engine, the transmission, the hybrid electric motor, the power electronics between the 

hybrid electric motor and the RESS, and the RESS. You may ask us to modify the 

provisions of this section to allow testing non-electric hybrid vehicles, consistent with 

good engineering judgment. 

(a) SetupSet up the engine according to §40 CFR 1065.110 to account for work inputs 

and outputs and accessory work.

(b) Use the equations of this paragraph (b) to define the torque and speed setpoints at the 

output shaft of the transmission

(i) Calculate total road load force using §1066.210 (d)(4) 

(ii) Torque at transmission output shaft is defined as follows

ds

d

r FR T

k

⋅

= Eq. §1037.550-1
(iii) Rotational speed at the transmission output shaft is defined as follows

d

ds 2

S k

n

π r

⋅

=

⋅ ⋅

Eq. §1037.550-2

Where:

nds = rotational speed of drive shaft.

Tds = torque at the drive shaft.

r = radius of loaded tire.

FR = total road load force to be applied at the surface of the roll.

kd = final drive ratio.

S = linear speed of the test cycle.

(c) Follow the vehicle cycle as defined in §1037.510. Collect CO2 emissions during 

operationwhile operating the system over the test cycles specified duty cycle(s).in 

§1037.510.

(d) Use the provisions of 40 CFR part 1066 to (c) Collect and measure emissions as 

described in 40 CFR part 1066. Calculate emission rates in grams per ton-mile without 

rounding.

(e) Send brake signal when throttle position is equal to zero and vehicle speed is greater 

than vehicle speed Determine values for A, B, C, and M for the vehicle being simulated 

as specified in 40 CFR part 1066. If you will apply an improvement factor or test cycle. 

The brake signal should be turned “off” when the torque measured at the transmission 

output shaft is less than the torque defined by equation 1 of this section, Tds. To prevent 

brake signal from dithering use good engineering judgment to set a delay before changing 

the brake state.results to multiple vehicle configurations, use values of A, B, C, M, kd, and 

r that represent the vehicle configuration with the smallest potential reduction in 

greenhouse gas emissions as a result of the hybrid capability. 

(f(d) Calculate the transmission output shaft’s angular speed target for the driver model, 

fnref,driver, from the linear speed associated with the vehicle cycle using the following 

equation:

, d

nrefi,driver 2

i cycle S k

f

π r

⋅

=

⋅ ⋅

Where:

Scyclei = vehicle speed of the test cycle for each point i.

kd = final drive ratio (the angular speed of the transmission output shaft divided by the 

angular speed of the drive axle), as declared by the manufacturer.

r = radius of the loaded tires, as declared by the manufacturer.

(e) Use either speed control or torque control to program the dynamometer to follow the 

test cycle, as follows: 

(1) Speed control. Program dynamometers using speed control as described in this 

paragraph (e)(1). We recommend speed control for automated manual transmissions 

or other designs where there is a power interrupt during shifts. Calculate the 

transmission output shaft’s angular speed target for the dynamometer, fnref,dyno, from 

the measured linear speed at the dynamometer rolls using the following equation:
i,ref d

nrefi,dyno 2

S k

f

π r

⋅

=

⋅ ⋅

Where:

( ( ))

2 i i-1

i,ref meas,i i i i,ref-1

t t S FR A B S C S S

M

−

= − + ⋅ + ⋅ +

t = elapsed time in the driving schedule as measured by the dynamometer, in seconds. 

Let ti-1 = 0.

d i

meas,i

k T FR

r

⋅

=

n,i

i

d

2 r f

S

k

⋅ ⋅ ⋅ π

=

Where:

Ti = instantaneous measured torque at the transmission output shaft.

 

fn,i = instantaneous measured angular speed of the transmission output shaft.

(2) Torque control. Program dynamometers using torque control as described in this 

paragraph (e)(2). 

(i) Calculate the transmission output shaft’s torque target, Trefi, using the 

following equation:

i

ref,i

d

r FR T

k

⋅

=

Where:

FRi = total road load force at the surface of the roll, calculated using the equation 

in 40 CFR 1066.210(d)(4), as specified in paragraph (e)(2)(ii) of this section.

(ii) Calculate the total road load force based on instantaneous speed values, Si, 

calculated from the equation in paragraph (e)(1) of this section.

(3) For each test, validate the measured transmission output shaft’s speed or torque 

with the torque defined by Eq. 1 of this sectioncorresponding reference values

according to §40 CFR 1065.514(e) and using the table 1 of this section. ). You may 

delete the points when the vehicle is braking or stopped. Perform the validation 

based on speed and torque values at the transmission output shaft. For steady-state 

tests (55 mph and 65 mph cruise), apply cycle-validation criteria by treating the 

sampling periods from the two tests as a continuous sampling period. Perform this 

validation based on the following parameters for either speed-control or torquecontrol, as applicable:

Table 1 of §1037.550 – Default Statistical criteria for validating duty cycles 

Parameter Speed Control Torque Control

Slope, a1 0.950 < a1 < 1.030 0.830950 < a1 < 1.030 

Absolute value of intercept, 

|a0| 

< 2.0 % of maximum test 

speed

< 2.0 % of maximum 

torque 

Formatted Table

Inserted Cells
Standard error of estimate, 

SEE 

< 5 % of maximum test 

speed < 10 % of maximum torque

Coefficient of 

determination, r

2

 

> 0.970 > 0.850 

 (f) Send a brake signal when throttle position is equal to zero and vehicle speed is greater 

than the reference vehicle speed from the test cycle. The brake signal should be turned 

off when the torque measured at the transmission output shaft is less than the reference 

torque. Set a delay before changing the brake state using good engineering judgment to 

prevent the brake signal from dithering.

(g) The driver model should attemptbe designed to follow the cycle as closely as possible 

and must meet the requirements of §40 CFR 1066.330430 (e).) for transient testing and 

§1037.510 for steady-state testing.

(h) Validate overall driver accuracy according to §1066.330 (n).

(i) Follow J2711 to correct emissions for NEC.

(h) Correct for the net energy change of the energy storage device as described in 40 CFR 

1066.501.

(i) Follow the provisions of §1037.510 to weight the cycle results and §1037.615 to 

calculate improvement factors and benefits for advanced technologies.

Subpart G—Special Compliance Provisions 

§ 1037.601 What compliance provisions apply to these vehicles? 

(a) Engine and vehicle manufacturers, as well as owners and operators of vehicles subject 

to the requirements of this part, and all other persons, must observe the provisions of this 

part, the provisions of the Clean Air Act, and the following provisions of 40 CFR part 

1068: 

(1) The exemption and importation provisions of 40 CFR part 1068, subparts C and 

D, apply for vehicles subject to this part 1037, except that the hardship exemption 

provisions of 40 CFR 1068.245, 1068.250, and 1068.255 do not apply for motor 

vehicles. 

(2) Manufacturers may comply with the defect reporting requirements of 40 CFR 

1068.501 instead of the defect reporting requirements of 40 CFR part 85. 

(b) Vehicles exempted from the applicable standards of 40 CFR part 86 are exempt from 

the standards of this part without request. Similarly, vehicles are exempt without request 

if the installed engine is exempted from the applicable standards in 40 CFR part 86. 

(c) The prohibitions of 40 CFR 86.1854-12 apply for vehicles subject to the requirements 

of this part. The actions prohibited under this provision include the introduction into U.S. 

commerce of a complete or incomplete vehicle subject to the standards of this part where 

the vehicle is not covered by a valid certificate of conformity or exemption. 

(d) Except as specifically allowed by this part, it is a violation of section 203(a)(1) of the 

Clean Air Act (42 U.S.C. 7522(a)(1)) to introduce into U.S. commerce a tractor 

containing an engine not certified for use in tractors; or to introduce into U.S. commerce 

a vocational vehicle containing a light heavy-duty or medium heavy-duty engine not 
certified for use in vocational vehicles. This prohibition generally applies especially to 

the vehicle manufacturer. 

(e) A vehicle manufacturer that completes assembly of a vehicle at two or more facilities

may ask to use as the date of manufacture for that vehicle the date on which 

manufacturing is completed at the place of main assembly, consistent with provisions of 

49 CFR 567.4. Note that such staged assembly is subject to the provisions of 40 CFR 

1068.260(c). Include your request in your application for certification, along with a 

summary of your staged-assembly process. You may ask to apply this allowance to some 

or all of the vehicles in your vehicle family. Our approval is effective when we grant 

your certificate. We will not approve your request if we determine that you intend to use 

this allowance to circumvent the intent of this part. 

 

§ 1037.610 Vehicles with innovative technologies.

(a) You may ask us to apply the provisions of this section for CO2 emission reductions 

resulting from vehicle technologies that were not in common use with heavy-duty 

vehicles before model year 2010 that are not reflected in the GEM simulation tool. These 

provisions may be applied for CO2 emission reductions reflected using the specified test 

procedures, provided they are not reflected in the GEM. We will apply these provisions 

only for technologies that will result in measurable, demonstrable, and verifiable realworld CO2 emission reductions. 

(b) The provisions of this section may be applied as either an improvement factor or as a 

separate credit, consistent with good engineering judgment. We recommend that you 

base your credit/adjustment on A to B testing of pairs of vehicles differing only with 

respect to the technology in question. 

(1) Calculate improvement factors as the ratio of in-use emissions with the 

technology divided by the in-use emissions without the technology. Use the 

improvement-factor approach where good engineering judgment indicates that the 

actual benefit will be proportional to emissions measured over the test procedures 

specified in this part. 

(2) Calculate separate credits (g/ton-mile) based on the difference between the in-use 

emission rate with the technology and the in-use emission rate without the 

technology. Multiply this difference by the number of vehicles, standard payload, 

and useful life. Use the separate-credit approach where good engineering judgment 

indicates that the actual benefit will be not be proportional to emissions measured 

over the test procedures specified in this part.

(3) We may require you to discount or otherwise adjust your improvement factor or 

credit to account for uncertainty or other relevant factors.

(c) You may perform A to B testing by measuring emissions from the vehicles during 

chassis testing or from in-use on-road testing. We recommend that you perform on-road 

testing according to SAE J1321 Joint TMC/SAE Fuel Consumption Test Procedure Type 

II Reaffirmed 1986-10 or SAE J1526 Joint TMC/SAE Fuel Consumption In-Service Test 

Procedure Type III Issued 1987-06 (see §1037.810 for information availability of SAE 

standards), subject to the following provisions:

(1) The minimum route distance is 100 miles. 

(2) The route selected must be representative in terms of grade. We will take into 

account published and relevant research in determining whether the grade is 
representative. 

(3) The vehicle speed over the route must be representative of the drive-cycle 

weighting adopted for each regulatory subcategory. For example, if the route selected 

for an evaluation of a combination tractor with a sleeper cab contains only interstate 

driving, the improvement factor would apply only to 86 percent of the weighted 

result. 

(4) The ambient air temperature must be between 5 and 35°C, unless the technology 

requires other temperatures for demonstration. 

(5) We may allow you to use a Portable Emissions Measurement System (PEMS) 

device for measuring CO2 emissions during the on-road testing.

(d) Send your request to the Designated Compliance Officer. Include a detailed 

description of the technology and a recommended test plan. Also state whether you 

recommend applying these provisions using the improvement-factor method or the 

separate-credit method. We recommend that you do not begin collecting test data (for 

submission to EPA) before contacting us. For technologies for which the engine 

manufacturer could also claim credits (such as transmissions in certain circumstances), 

we may require you to include a letter from the engine manufacturer stating that it will 

not seek credits for the same technology.

(e) We may seek public comment on your request, consistent with the provisions of 40 

CFR 86.1866. However, we will generally not seek public comment on credits or 

adjustments based on A to B chassis testing performed according to the duty-cycle testing 

requirements of this part or in-use testing performed according to paragraph (c) of this 

section.

§ 1037.615 Hybrid vehicles and other advanced technologies. 

(a) This section applies for hybrid vehicles with regenerative braking, vehicles equipped 

with Rankine-cycle engines, electric vehicles, and fuel cell vehicles. You may not 

generate credits for engine features for which the engines generate credits under 40 CFR 

part 1036. 

(b) Generate advanced technology emission credits for hybrid vehicles that include 

regenerative braking (or the equivalent) and energy storage systems, fuel cell vehicles,

and vehicles equipped with Rankine-cycle engines as follows: 

(1) Measure the effectiveness of the hybridadvanced system by chassis testing a 

vehicle equipped with the hybridadvanced system and an equivalent conventional 

vehicle. 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, intended (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 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 hybridadvanced vehicle is considered Vehicle B. We may specify 

an alternate cycle if your vehicle includes a power take-off. 

(2) Calculate an improvement factor and g/ton-mile benefit using the following 

equations and parameters: 
(i) Improvement Factor = [(Emission Rate A) – (Emission Rate B)]/(Emission 

Rate A) 

(ii) g/ton-mile benefit = Improvement Factor × (ModelingGEM Result B) 

(iii) Emission Rates A and B are the g/ton-mile CO2 emission rates of the 

conventional and hybridadvanced vehicles, respectively, as measured under the 

test procedures specified in this section. ModelingGEM Result B is the g/tonmile CO2 emission rate resulting from emission modeling of the hybridadvanced

vehicle as specified in § 1037.520.

(3) Use the equations of § 1037.705 to convert the g/ton-mile benefit to emission 

credits (in Mg). Use the g/ton-mile benefit in place of the (Std-FEL) term. 

(c) See § 1037.525 for special testing provisions related to hybrid vehicles equipped with 

power take-off units. 

(d) You may use an engineering analysis to calculate an improvement factor for fuel cell 

vehicles based on measured emissions from the fuel cell vehicle. 

(e) For electric vehicles, calculate CO2 credits using an FEL of 0 g/ton-mile. 

(f)(f) As specified in subpart H of this part, credits generated under this section may be 

used under this part 1037 outside of the averaging set in which they were generated, or 

you may convert the credits into engine-based credits for useused under 40 CFR part 

1036, consistent with good engineering judgment.. 

§ 1037.611 Vehicles with (g) You may certify using both provisions of this section and 

the innovative technologies.

This section applies for CO2 reductions resulting from technologies that weretechnology 

provisions of §1037.610, provided you do not in common use before 2010 that are not 

reflected in the specified test procedures and double count emission models. We may 

allow you to generate emission credits consistent with the provisions of 40 CFR 86.1866-

12(d). benefits.

§ 1037.620 Shipment of incomplete vehicles to secondary vehicle manufacturers. 

This section specifies how manufacturers may introduce partially complete vehicles into 

U.S. commerce. 

(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: 

(1) Tractors. Manufacturers may introduce partially complete tractors into U.S. 

commerce if they are covered by a certificate of conformity for tractors and will be in 

their certified tractor configuration before they reach the ultimate purchasers. For 

example, this would apply for sleepers initially shipped without the sleeper 

compartments attached. Note that delegated assembly provisions may apply (see 40 

CFR 1068.260261). 

(2) Vocational vehicles. Manufacturers may introduce partially complete vocational 

vehicles into U.S. commerce if they are covered by a certificate of conformity for 

vocational vehicles and will be in their certified vocational configuration before they 

reach the ultimate purchasers. Note that delegated assembly provisions may apply 

(see 40 CFR 1068.260261). 
(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. 

(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. 

(1) A secondary manufacturer may finish assembly of partially complete vehicles in 

the following cases: 

(i) It obtains a vehicle that is not fully assembled with the intent to manufacture a 

complete vehicle in a certified configuration. 

(ii) It obtains a vehicle with the intent to modify it to a certified configuration 

before it reaches the ultimate purchaser. For example, this may apply for 

converting a gasoline-fueled vehicle to operate on natural gas under the terms of a 

valid certificate. 

(2) Manufacturers may introduce partially complete vehicles into U.S. commerce as 

described in this sectionparagraph (b) if they have a written request for such vehicles 

from a secondary vehicle manufacturer that will finish the vehicle assembly and has 

certified the vehicle. (or the vehicle has been exempted or excluded from the 

requirements of this part). . The written request must include a statement that the 

secondary manufacturer has a certificate of conformity (or exemption/exclusion) for 

the vehicle and identify a valid vehicle family name associated with each vehicle 

model ordered (or the basis for an exemption/exclusion). The original vehicle 

manufacturer must apply a removable label meeting the requirements of 40 CFR 

1068.45 that identifies the corporate name of the original manufacturer and states that 

the vehicle is exempt under the provisions of § 1037.620. The name of the certifying 

manufacturer must also be on the label or, alternatively, on the bill of lading that 

accompanies the vehicles during shipment. The original manufacturer may not apply 

a permanent emission control information label identifying the vehicle's eventual 

status as a certified vehicle. 

(3) If you are the secondary manufacturer thatand you will hold the certificate (that is, 

the secondary manufacturer), you must include the following information in your

application for certification: 

(i) Identify the original manufacturer of the partially complete vehicle or of the 

complete vehicle you will modify. 

(ii) Describe briefly how and where final assembly will be completed. Specify 

how you have the ability to ensure that the vehicles will conform to the 

regulations in their final configuration. (Note: This section prohibits using the 

provisions of this sectionparagraph (b) unless you have substantial control over 

the design and assembly of emission controls.) 

(iii) State unconditionally that you will not distribute the vehicles without 

conforming to all applicable regulations. 
(4) If you are a secondary manufacturer and you are already a certificate holder for 

other families, you may receive shipment of partially complete vehicles after you 

apply for a certificate of conformity but before the certificate's effective date. This 

exemption allows the original manufacturer to ship vehicles after you have applied 

for a certificate of conformity. Manufacturers may introduce partially complete 

vehicles into U.S. commerce as described in this paragraph (b)(4) if they have a 

written request for such vehicles from a secondary manufacturer stating that the 

application for certification has been submitted (instead of the information we specify 

in paragraph (b)(2) of this section). We may set additional conditions under this 

paragraph (b)(4) to prevent circumvention of regulatory requirements. 

(5) The provisions of this section also apply for shipping partially complete vehicles 

if the vehicle is covered by a valid exemption and there is no valid vehicle family 

name that could be used to represent the vehicle model. Unless we approve otherwise 

in advance, you may do this only when shipping vehicles to secondary manufacturers 

that are certificate holders. In this case, the secondary manufacturer must identify the 

regulatory citation providing the applicable exemption instead of a valid vehicle

family name when ordering vehicles from the original manufacturer.

(6(5) Both original and secondary manufacturers must keep the records described in 

this section for at least five years, including the written request for exempted vehicles 

and the bill of lading for each shipment (if applicable). The written request is deemed 

to be a submission to EPA. 

(76) These provisions are intended only to allow yousecondary manufacturers to 

obtain or transport vehicles in the specific circumstances identified in this section so 

any exemption under this section expires when the vehicle reaches the point of final 

assembly identified in paragraph (b)(3)(ii) of this section.

(87) For purposes of this section, an allowance to introduce partially complete 

vehicles into U.S. commerce includes a conditional allowance to sell, introduce, or 

deliver such vehicles into commerce in the United States or import them into the 

United States. It does not include a general allowance to offer such vehicles for sale 

because this exemption is intended to apply only for cases in which the certificate 

holder already has an arrangement to purchase the vehicles from the original 

manufacturer. This exemption does not allow the original manufacturer to 

subsequently offer the vehicles for sale to a different manufacturer who will hold the 

certificate unless that second manufacturer has also complied with the requirements 

of this part. The exemption does not apply for any individual vehicles that are not 

labeled as specified in this section or which are shipped to someone who is not a 

certificate holder. 

(98) We may suspend, revoke, or void an exemption under this section, as follows: 

(i) We may suspend or revoke your exemption if you fail to meet the requirements 

of this section. We may suspend or revoke youran exemption forrelated to a 

specific secondary manufacturer if that manufacturer sells vehicles that are in not 

in a certified configuration in violation of the regulations. We may disallow this 

exemption for future shipments to the affected secondary manufacturer or set 

additional conditions to ensure that vehicles will be assembled in the certified 

configuration. 
(ii) We may void youran exemption for all the affected vehicles if you 

intentionally submit false or incomplete information or fail to keep and provide to 

EPA the records required by this section. 

(iii) The exemption is void for a vehicle that is shipped to a company that is not a 

certificate holder or for a vehicle that is shipped to a secondary manufacturer that 

is not in compliance with the requirements of this section. 

(iv) The secondary manufacturer may be liable for penalties for causing a 

prohibited act where the exemption is voided due to actions on the part of the 

secondary manufacturer. 

(d) Provide instructions along with partially complete vehicles including all information 

necessary to ensure that an engine will be installed in its certified configuration. 

§1037.630 Special purpose tractors. 

(a) PurposeGeneral 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.

(1) This allowance is intended only for vehicles that do not typically operate at 

highway speeds, or would otherwise not benefit from efficiency improvements 

designed for line-haul tractors. This allowance is limited to the following vehicle and 

application types: 

(i) Low-roof tractors intended for intra-city pickup and delivery, such as those 

that deliver bottled beverages to retail stores. 

(ii) Tractors intended for offroadoff-road operation (including mixed service 

operation), such as those with reinforced frames and increased ground clearance. 

(iii) Tractors with a GCWR over 120,000 pounds. 

(2) Where we determine that a manufacturer is not applying this allowance in good 

faith, we may require thatthe manufacturer to obtain preliminary approval before

using this allowance. 

(b) Requirements. The following requirements apply forwith respect to tractors 

reclassified under this section and the manufacturer of the vehicle: 

(1) The vehicle must fully conform fully to all requirements applicable to vocational 

vehicles under this part. 

(2) Vehicles reclassified under this section must be included incertified as a separate 

vehicle family. However, they remain part of the vocational regulatory sub-category 

and averaging set that applies for their weight class.

(3) You must include the following additional statement on the vehicle’s emission 

control information label under §1037.135: “THIS VEHICLE WAS CERTIFIED AS 

A VOCATIONAL TRACTOR UNDER 40 CFR 1037.630.”. 

(4) You must keep records for three years to document your basis for believing the 

vehicles will be used as vocational tractorsdescribed in paragraph (a)(1) of this 

section. Include in your application for certification a brief description of your basis. 

(c) Production limit. No manufacturer may produce more than 21,000 vehicles under this 

section in any consectutive three model year period. This means you may not exceed 

6,000 in a given model year if the combined total for the previous two years was 15,000. 

The production limit applies with respect to all Class 7 and Class 8 tractors certified or 
exempted as vocational tractors. Note: that in most cases, the provisions of paragraph (a) 

of this section will limit the allowable number of vehicles allowed to be produced to a 

number lower than the production limit of this paragraph (c). 

(d) Offroad exemption. All of the provisions of this section apply for tractors exempted 

under §1037.631, except as follows:

(d) Off-road exemption. All the provisions of this section apply for vocational tractors 

exempted under §1037.631, except as follows:

(1) The vehicles are required to comply with the requirements of §1037.631 instead 

of the requirements that would otherwise apply to vocational vehicles. Vehicles 

complying with the requirements of §1037.631 and using an engine certified to the 

standards of 40 CFR part 1036 are deemed to fully conform to all requirements 

applicable to vocational vehicles. under this part. 

(2) The vehicles must be labeled as specified under §1037.631 instead of as specified 

in paragraph (b)(3) of this section. 

§ 1037.631 Exemption for vocational vehicles intended for offroadoff-road use. 

This section provides an exemption from the greenhouse gas standards of this part for 

certain vocational vehicles intended to be used extensively in offroadoff-road

environments such as forests, oil fields, and construction sites. This sexempction does 

not exempt the engine used in the vehicle from the standards of 40 CFR part 86 or part 

1036. Note that you may not include these exempted vehicles in any credit calculations 

under this part. 

(a) Criteria.Qualifying criteria. Vocational vehicles intended for offroadoff-road use that 

meeting either the criteria of paragraph (a)(1) or (2) of this section are produced with 

exempt without request, subject to the provisions of this section. 

(1) Vehicles are exempt if the tires thatinstalled on the vehicle have a maximum 

speed rating at or below 55 mph. 

(2) Vehicles are exempt if they were primarily designed to perform work off-road 

(such as in oil fields, forests, or construction sites), and they meet at least one of the 

criteria of paragraph (a)(2)(i) of this section and at least one of the criteria of 

paragraph (a)(2)(ii) of this section. 

(i) The vehicle must have affixed components designed to work in an off-road 

environment (i.e., hazardous material equipment or off-road drill equipment) or 

be designed to operate at low speeds such that it is unsuitable for normal highway 

operation.

(ii) The vehicle must meet one of the following criteria:

(A) Have an axle that has a gross axle weight rating (GAWR) of 29,000 

pounds.

(B) Have a speed attainable in 2 miles of not more than 33 mph. 

(C) Have a speed attainable in 2 miles of not more than 45 mph, an unloaded 

vehicle weight that is not less than 95 percent of its gross vehicle weight 

rating (GVWR), and no capacity to carry occupants other than the driver and 

operating crew.

(b) Tractors. The provisions of this section may be applied to apply for tractors only if 

each tractor qualifies as a vocational tractor under §1037.630. 

(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. 

(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.(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. 

(d) Labeling. (3) You must include the following additional statement on the vehicle’s 

emission control information label under §1037.135: “THIS VEHICLE WAS 

EXEMPTED UNDER 40 CFR 1037.631.”. 

§1037.640 Variable vehicle speed limiters. This section specifies provisions that apply 

for vehicle speed limiters (VSLs) that you model under §1037.520. This does not apply 

for VSLs that you do not model under §1037.520. 

(a) General. The regulations of this part do not constrain how you may design VSLs for 

your vehicles. For example, you may design your VSL to have a single fixed speed limit 

or a soft-top speed limit. You may also design your VSL to expire after accumulation of 

a predetermined number of miles. However, designs with soft tops or expiration features 

are subject to proration provisions under this section that do not apply to fixed VSLs that 

do not expire. 

(b) Definitions. The following definitions apply for purposes of this section.:

(1) Default speed limit means the speed limit that normally applies for the vehicle,

except as follows: 

(i) The default speed limit for adjustable VSLs must represent the speed limit that 

applies when the VSL is adjusted to its highest setting under paragraph (c) of this 

section.(i) The default speed limit for adjustable VSLs must represent the speed 

limit that applies when the VSL is adjusted to its highest setting under paragraph 

(c) of this section.

(ii) For VSLs with soft tops, the default speed does not include speeds possible 

only during soft-top operation. 

(iii) For expiring VSLs, the default does not include speeds that are possible only 

after the expiration. 

(2) Soft-top speed limit means the highest speed limit that applies during soft-top 

operation.
(3) Maximum soft-top duration means the maximum amount of time that a vehicle 

could operate above the default speed limit.(2) Soft-top speed limit means the highest 

speed limit that applies during soft-top operation.

(3) Maximum soft-top duration means the maximum amount of time that a vehicle 

could operate above the default speed limit. 

(4) Certified VSL means a VSL configuration that applies when a vehicle is new and 

until it expires. 

(5) Expiration point means the mileage at which a vehicle’s certified VSL expires (or 

the point at which the tamper protections expire). 

(6) Effective speed limit has the meaning given in paragraph (d) of this section. 

(c) Adjustments. 

(6) Effective speed limit has the meaning given in paragraph (d) of this section. 

(c) Adjustments. You may design your VSL to be adjustable,; however, this may affect 

the value you use in the GEM model. 

(1) Except as specified in paragraph (c)(2) of this section, any adjustments that can be 

made to the engine, vehicle, or their controls that change the VSL’s actual speed limit 

of the VSL are considered to be adjustable operating parameters. Compliance is 

based on the vehicle being adjusted to have itsthe highest speed limit within this 

range. 

(2) The following adjustments are not adjustable parameters:

(i) Adjustments made only to account for changing tire size or final drive ratio.

(ii) Adjustments protected by encrypted controls or passwords.

(iii) Adjustments possible only after the VSL’s expiration point.

(d) Effective speed limit. (2) The following adjustments are not adjustable 

parameters:

(i) Adjustments made only to account for changing tire size or final drive ratio.

(ii) Adjustments protected by encrypted controls or passwords.

(iii) Adjustments possible only after the VSL’s expiration point.

(d) Effective speed limit. (1) For VSLs without soft tops or expiration points that expire 

before 1,259,000 miles, the effective speed limit is the highest speed limit that results 

by adjusting the VSL or other vehicle parameters consistent with the provisions of 

paragraph (c) of this section. 

(2) For VSLs with soft tops and/or expiration points, the effective speed limit is 

calculated as specified in this paragraph (d)(2)), which is based on 10 hours of 

operation per day. (i) (394 miles per day for day cabs and 551 miles per day for 

sleeper cabs). Note that this calculation assumes that a fraction of this operation is 

speed-limited (3.9 hours and 252 miles for day cabs, and 7.3 hours and 474 miles for 

sleeper cabs). Use the following equation to calculate yourthe effective speed limit (,

rounded to the nearest 0.1 mph)::

Effective speed = ExF * [STF* STSL + (1-STF) * DSL] + (1-ExF)*65 mph 

Where: 

(i) ExF = expiration point miles/1,259,000 miles 

(ii) STF = maximum number of allowable soft top operation hours per day / 3.9 hours 

for day cabs (or maximum miles per day / 252)
(iii) STF = maximum number of allowable soft top operation hours per day / 7.3 

hours for sleeper cabs (or maximum miles per day / 474)

(iv) STSL = the soft top speed limit 

DSL = the default speed limit(v) DSL = the default speed limit

1037.645 In-use compliance with family emission limits (FELs). 

You may ask us to apply a higher in-use FEL for certain in-use vehicles, subject to the 

provisions of this section. Note that §1037.225 contains provisions related to changing 

FELs during a model year. 

(a) Purpose.(a) Purpose. This section is intended to address circumstances in which it is 

in the public interest to apply a higher in-use FEL based on forfeiture offorfeiting an 

appropriate number of emission credits. 

(b) FELs. We may apply higher in-use FELs to your vehicles as follows: 

(1) Where your vehicle family includes more than one sub-family with different 

FELs, we may apply a higher FEL within the family than was applied to the 

vehicle’s configuration in your final ABT report. For example, if your vehicle 

family included three sub-families with FELs of 200 g/ton-mile, 210 g/ton-mile, 

and 220 g/ton-mile, we may apply a 220 g/ton-mile in-use FEL to vehicles that 

were originally designated as part of the 200 g/ton-mile or 210 g/ton-mile subfamilies. 

(2) Without regard to the number of sub-families in your certified vehicle family, 

we may specify new sub-families with higher FELs than were included in your 

final ABT report. We may apply these higher FELs as in-use FELs for your 

vehicles. For example, if your vehicle family included three sub-families with 

FELs of 200 g/ton-mile, 210 g/ton-mile, and 220 g/ton-mile, we may specify a 

new 230 g/ton-mile sub-family. 

(3) In specifying sub-families and in-use FELs, we would intend to accurately 

reflect the actual in-use performance of your vehicles, consistent with the 

specified testing and modeling provisions of this part. 

(c) Equivalent families. We may apply the higher FELs to other families in other model 

years if they used equivalent emission controls. 

(d) Credit forfeiture. Where we specify higher in-use FELs under this section, you must 

forfeit CO2 emission credits based on the difference between the in-use FEL and the 

otherwise applicable FEL. Calculate the amount of credits to be forfeited using the 

applicable equation in §1037.705, by substituting the otherwise applicable FEL for the 

standard and the in-use FEL for the otherwise applicable FEL. 

(de) Requests. Submit your request to the Designated Compliance Officer. Include the 

following in your request: 

(1) The vehicle family name, model year, and name/description of the 

configuration(s) affected. 

(2) A list of other vehicle families/configurations/model years that may be 

affected. 

(3) The otherwise applicable FEL for each configuration along with your 

recommendations for higher in-use FELs. 

(4) Your source of credits for forfeiture. 
(ef) Relation to recall. You may not request higher in-use FELs for any vehicle families 

for which we have made a determination of nonconformance and ordered a recall. You 

may, however, make such requests for vehicle families for which you are performing a 

voluntary emission recall. 

(fg) Approval. EPAWe may approve your request if we determine that you meet the 

requirements of this section and such approval is in the public interest. We may include 

appropriate conditions with our approval or approvedwe may approve your request with 

modifications. 

§1037.650 Tire manufacturers. 

This section describes how the requirements of this part apply with respect to tire 

manufacturers that choose to provide test data or emission warranties for purposes of this 

part. 

(a) Testing. You are responsible as follows for test tires and emission test results that you 

provide to vehicle manufacturers for the purpose of the manufacturer submitting them to 

EPA for certification under this part.: 

(1) Such test results are deemed under §1037.825 to be submissions to EPA. This 

means that you may be subject to criminal penalties under 18 U.S.C. 1001 if you 

knowingly submit false test results to the manufacturer. 

(2) You may not cause a vehicle manufacturer to violate the regulations by rendering 

inaccurate emission test results you provide (or emission test results from testing of 

test tires you provide) to the vehicle manufacturer. 

(3) Your provision of test tires and emission test results to vehicle manufacturers for 

the purpose of certifying under this part is deemed to be an agreement to provide tires 

to EPA for confirmatory testing under §1037.201. 

(b) Warranty. You may contractually agree to process emission warranty claims on 

behalf of the manufacturer certifying the vehicle with respect to tires you produce. 

(1) Your fulfillment of the warranty requirements of this part is deemed to fulfill the 

vehicle manufacturer’s warranty obligations under this part with respect to tires you 

warrant. 

(2) You may not cause a vehicle manufacturer to violate the regulations by failing to 

fulfill the emission warranty requirements that you contractually agreed to fulfill. 

§1037.655 Post-useful life vehicle modifications. 

This section specifies vehicle modifications that may occur after a vehicle reaches the 

end of its regulatory useful life. It does not apply with respect to modifications that occur 

within the useful life period. It also does not apply with respect to engine modifications 

or recalibrations. Note that many such modifications to the vehicle during the useful life 

and to the engine at any time are presumed to violate 42 U.S.C 7522(a)(3)(A). 

(a) General. Except as allowed by this section, it is prohibited for any person to remove 

or render inoperative any emission control device installed to comply with the 

requirements of this part 1037. 

(b) Allowable modifications. You may modify a vehicle for the purpose of reducing 

emissions, provided you have a reasonable technical basis for knowing that such 

modification will not increase emissions of any other pollutant. Reasonable technical 

basis has the meaning given in 40 CFR 1068.30. This generally requires you to have 
information that would lead an engineer or other person familiar with engine and vehicle 

design and function to reasonably believe that the modifications will not increase 

emissions of any regulated pollutant. 

(c) Examples of allowable modifications. The following are examples of allowable 

modifications: 

(1) It is generally allowable to remove tractor roof fairings after the end of the 

vehicle’s useful life if the vehicle will no longer be used primarily to pull box 

trailers. 

(2) Other fairings may be removed after the end of the vehicle’s useful life if the 

vehicle will no longer be used significantly on highways with vehicle speed of 55 

miles per hour or higher. 

(d) Examples of prohibited modifications. The following are examples of modifications 

that are not allowable: 

(1) No person may disable a vehicle speed limiter prior to its expiration point. 

(2) No person may remove aerodynamic fairings from tractors that are used 

primarily to pull box trailers on highways. 

§1037.660 Automatic engine shutdown systems. 

This section specifies requirements that apply for certified automatic engine shutdown 

systems (AES) that are modeled under §1037.520. ThisIt does not apply for AES 

systems that you do not model under §1037.520. 

(a) Minimum requirements. Your AES system must meet all of the requirements of this 

paragraph (a) to be modeled under §1037.520. The system must shut down the engine 

within 300 seconds when all of the following conditions are met: 

(1) The transmission is set in neutral with the parking brake engaged (or the 

transmission is set to park if so equipped). 

(2) The operator has not reset the system timer within the 300 seconds by 

changing the position of the accelerator, brake, or clutch pedal; or by some other 

mechanism we approve. 

(3) None of the override conditions of paragraph (b) of this section are met. 

(b) Override conditions. The system may delay shutting the engine down while any of 

the conditions of this paragraph (b) apply. Engines equipped with auto restart may restart 

during override conditions. Note that these conditions allow the system to delay 

shutdown or restart, but do not allow it to reset the timer. The system may delay 

shutdown—

(1) The system may delay shutdown(1) While an exhaust emission control device 

is regenerating,. The period considered to be regeneration for purposes of this 

allowance must be consistent with good engineering judgment and may differ in 

length from the period considered to be regeneration for other purposes. For 

example, in some cases it may be appropriate to include a cool down period for 

this purpose but not for infrequent regeneration adjustment factors. 

(2) The system may delay shutdown(2) If necessary while servicing the vehicle, 

provided the deactivation of the AES system is accomplished using a diagnostic 

scan tool. The system must be automatically reactivated when the engine is 

shutdown for more than 60 minutes. 
(3) The system may delay shutdown isIf the vehicle’s main battery state-ofcharge is not sufficient to allow the main engine to be restarted. 

(4) The system may delay shutdown(4) If the external ambient temperature 

reaches a level below which or above which the cabin temperature cannot be 

maintained within reasonable heat or cold exposure threshold limit values for the 

health and safety of the operator (not merely comfort). 

(5) The system may delay shutdown(5) If the vehicle’s engine coolant 

temperature is too low according to the manufacturer's engine protection 

guidance. This may also apply for fuel or oil temperatures. This allows the 

engine to continue operating until it reaches a predefined temperature at which the 

shutdown sequence of paragraph (a) of this section would resume. 

(6) The system may delay shutdown while the vehicle's main engine is operating 

in power take-off (PTO) mode. For purposes of this paragraph (b)(6), an engine 

is considered to be in PTO mode when a switch or setting designating power takeoffPTO mode shall beis enabled on vehicles with this utility. Switching the engine 

off power take-off mode shall enable the shutdown sequence of paragraph (a) to 

resume.. 

(c) Expiration of AES systems. 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: 

Input = 5 g CO2/ton-mile *× (miles at expiration / 1,259,000 miles) 

(d) Adjustable parameters. Provisions that apply generally with respect to adjustable 

parameters also apply to the AES system operating parameters, except the following are 

not considered to be adjustable parameters: 

(1) Accelerator, brake, and clutch pedals are not considered to be adjustable 

parameters, with respect to resetting the idle timer. Parameters associated with other

timer reset mechanisms we approve are also not adjustable parameters. 

(2) Bypass parameters allowed for vehicle service under paragraph (b)(2) are not 

adjustable parametersof this section. 

(3) Parameters that are adjustable only after the expiration point are not considered to 

be adjustable parameters under this part. 

Subpart H—Averaging, Banking, and Trading for Certification 

§ 1037.701 General provisions. 

(a) You may average, bank, and trade (ABT) emission credits for purposes of 

certification as described in this subpart and in subpart B of this part to show compliance 

with the standards of §§ 1037.105 and 1037.106. Participation in this program is 

voluntary. 

(b) Section 1037.740 restricts the use of emission credits to certain averaging sets.

(c(b) The definitions of Subpart I of this part apply to this subpart. The following 

definitions also apply: 

(1) Actual emission credits means emission credits you have generated that we have 

verified by reviewing your final report. 

(2) Averaging set means a set of vehicles in which emission credits may be 
exchanged. Credits generated by one vehicle may only be used by other vehicles in 

the same averaging set. Note that an averaging set may comprise more than one 

regulatory subcategory. See § 1037.740. 

(3) Broker means any entity that facilitates a trade of emission credits between a 

buyer and seller. 

(4) Buyer means the entity that receives emission credits as a result of a trade. 

(5) Reserved emission credits means emission credits you have generated that we 

have not yet verified by reviewing your final report. 

(6) Seller means `the entity that provides emission credits during a trade. 

(7) Standard means the emission standard that applies under subpart B of this part for 

vehicles not participating in the ABT program of this subpart. 

(8) Trade means to exchange emission credits, either as a buyer or seller. 

(c) Emission credits may be exchanged only within an averaging set as specified in 

§ 1037.740.

(d) You may not use emission credits generated under this subpart to offset any emissions 

that exceed an FEL or standard, except as allowed by §1037.645. 

(e) [Reserved]

(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.

(f) Emission credits may be used in the model year they are generated. Surplus emission 

credits may be used for past model years or banked for future model years. Surplus 

emission credits may sometimes be used for past model years, as described in §1037.745. 

(g) You may increase or decrease an FEL during the model year by amending your 

application for certification under § 1037.225. The new FEL may apply only to vehicles 

you have not already introduced into commerce. 

(h) See §1037.740 for special credit provisions that apply for credits generated under 

§1037.104(d)(7), §1037.615 or 40 CFR 1036.615.

(i) Unless the regulations explicitly allow it, you may not calculate credits more than 

once for any emission reduction. For example, if you generate CO2 emission credits for a 

given hybrid vehicle under this part, no one may generate CO2 emission credits for the 

hybrid engine under 40 CFR part 1036. However, credits could be generated for identical 

engine used in vehicles that did not generate credits under this part.

§ 1037.705 Generating and calculating emission credits.

(a) The provisions of this section apply separately for calculating emission credits byfor 

each pollutant. 

(a) [Reserved]

(b) For each participating family or subfamily, calculate positive or negative emission 

credits relative to the otherwise applicable emission standard. Calculate positive 

emission credits for a family or subfamily that has an FEL below the standard. Calculate 

negative emission credits for a family or subfamily that has an FEL above the standard. 

Sum your positive and negative credits for the model year before rounding. Round the 
sum of emission credits to the nearest megagram (Mg), using consistent units throughout 

the following equations: 

(1) For vocational vehicles: 

Emission credits (Mg) = (Std-FEL) × (Payload Tons) × (Volume) × (UL) × (10-6) 

Where: 

Std = the emission standard associated with the specific tractor regulatory 

subcategory (g/ton-mile). 

FEL = the family emission limit for the vehicle subfamily (g/ton-mile). 

Payload tons = the prescribed payload for each class in tons (2.85 tons for light 

heavy-duty vehicles, 5.6 tons for medium heavy-duty vehicles, and 7.5 tons for heavy 

heavy-duty vehicles). 

Volume = (projected or actual) U.S. .-directed production volume of the vehicle 

subfamily subject to. For example, if you produce three configurations with the FTP

standardssame FEL, the subfamily production volume would be the sum of the 

production volumes for these three configurations. 

UL = useful life of the vehicle (110,000 miles for light heavy-duty vehicles, 185,000 

miles for medium heavy-duty vehicles, and 435,000 miles for heavy heavy-duty 

vehicles). 

(2) For tractors: 

Emission credits (Mg) = (Std-FEL) × (Payload tons) × (Volume) × (UL) × (10-6) 

Where: 

Std = the emission standard associated with the specific tractor regulatory 

subcategory (g/ton-mile). 

FEL = the family emission limit for the vehicle subfamily (g/ton-mile). 

Payload tons = the prescribed payload for each class in tons (12.5 tons for Class 7 and 

19 tons for Class 8). 

Volume = (projected or actual) U.S. .-directed production volume of the vehicle 

subfamily subject to the SET standards. 

UL = useful life of the tractor (435,000 miles for Class 8 and 185,000 miles for Class 

7). 

(c) As described in § 1037.730, compliance with the requirements of this subpart is 

determined at the end of the model year based on actual values for U.S.-directed 

production volumes. See § 1037.745 for provisions allowing you Keep appropriate 

records to continuedocument these production in cases where you have (or expect to 

have) a negative credit balance at the end of the yearvolumes. Do not include any of the 

following vehicles to calculate emission credits: 

(1) Vehicles that you do not certify to the CO2 standards of this part because they are 

permanently exempted under subpart G of this part or under 40 CFR part 1068. 

(2) Exported vehicles. 

(3) Vehicles not subject to the requirements of this part, such as those excluded under 

§ 1037.5. 

(4) Any other vehicles, where we indicate elsewhere in this part 1037 that they are not 
to be included in the calculations of this subpart. 

§ 1037.710 Averaging. 

(a) Averaging is the exchange of emission credits among your vehicle families. You may 

average emission credits only within the same averaging set. 

(b) You may certify one or more vehicle families (or subfamilies) to an FEL above the 

applicable standard, subject to any applicable FEL caps and other provisions in subpart B 

of this part, if you show in your application for certification that your projected balance 

of all emission-credit transactions in that model year is greater than or equal to zero (or 

that a negative balance is otherwise allowed by this part).under § 1037.745. 

(c) If you certify a vehicle family to an FEL that exceeds the otherwise applicable 

standard, you must obtain enough emission credits to offset the vehicle family’s deficit 

by the applicable due date: the due date for the final report required in § 1037.730. The 

emission credits used to address the deficit may come from your other vehicle families 

that generate emission credits in the same model year (or from later model years as 

specified in § 1037.745), from emission credits you have banked, or from emission 

credits you obtain through trading. 

§ 1037.715 Banking. 

(a) Banking is the retention of surplus emission credits by the manufacturer generating 

the emission credits for use in future model years for averaging or trading. 

(b) You may designate any emission credits you plan to bank in the reports you submit 

under § 1037.730 as reserved credits. During the model year and before the due date for 

the final report, you may designate your reserved emission credits for averaging or 

trading. 

(c) Reserved credits become actual emission credits when you submit your final report. 

However, we may revoke these emission credits if we are unable to verify them after 

reviewing your reports or auditing your records. 

(d) Banked credits retain the designation of the averaging set in which they were 

generated.

§ 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 may be used 

only withinremain subject to the averaging-set restrictions based on the averaging set in 

which they were generated. 

(b) You may trade actual emission credits as described in this subpart. You may also 

trade reserved emission credits, but we may revoke these emission credits based on our 

review of your records or reports or those of the company with which you traded 

emission credits. You may trade banked credits within an averaging set to any certifying 

manufacturer. 

(c) If a negative emission credit balance results from a transaction, both the buyer and 

seller are liable, except in cases we deem to involve fraud. See § 1037.255(e) for cases 

involving fraud. We may void the certificates of all vehicle families participating in a 

trade that results in a manufacturer having a negative balance of emission credits. See 
§ 1037.745. 

§ 1037.725 What must I include in my application for certification? 

(a) You must declare in your application for certification your intent to use the provisions 

of this subpart for each vehicle family that will be certified using the ABT program. You 

must also declare the FELs you select for the vehicle family or subfamily for each 

pollutant for which you are using the ABT program. Your FELs must comply with the 

specifications of subpart B of this part, including the FEL caps. FELs must be expressed 

to the same number of decimal places as the applicable standards. 

(b) Include the following in your application for certification: 

(1) A statement that, to the best of your belief, you will not have a negative balance of 

emission credits for any averaging set when all emission credits are calculated at the 

end of the year; or a statement that you will have a negative balance of emission 

credits for one or more averaging sets but that it is allowed under § 1037.745. 

(2) Detailed Calculations of projected emission credits (positive or negative) based on 

projected U.S.-directed production volumes. We may require you to include similar 

calculations from your other vehicle families to project your net credit balances for 

the model year. If you project negative emission credits for a family or subfamily, 

state the source of positive emission credits you expect to use to offset the negative 

emission credits. 

§ 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. We may waive the 

requirement to send the end-of year report, conditioned upon you sending the final report 

on time. We will not waive this requirement where you have a deficit for that model year 

or an outstanding deficit for a prior model year.

(b) Your end-of-year and final reports must include the following information for each 

vehicle family participating in the ABT program: 

(1) Vehicle-family and subfamily designations. 

(2) The regulatory subcategory and emission standards that would otherwise apply to 

the vehicle family. 

(3) The FEL for each pollutant. If you change the FEL after the start of production, 

identify the date that you started using the new FEL and/or give the vehicle 

identification number for the first vehicle covered by the new FEL. In this case, 

identify each applicable FEL and calculate the positive or negative emission credits as 

specified in § 1037.225. 

(4) The projected and actual U.S.-directed production volumes for the model year. If 

you changed an FEL during the model year, identify the actual production volume 

associated with each FEL. 

(5) Useful life. 

(6) Calculated positive or negative emission credits for the whole vehicle family. 

Identify any emission credits that you traded, as described in paragraph (d)(1) of this 

section. 

(7) If you have a negative credit balance for the averaging set in the given model 
year, specify whether the vehicle family (or certain subfamilies with the vehicle 

family) have a credit deficit for the year. Consider for example, a manufacturer with 

three vehicle families (“A”, “B”, and “C”) in a given averaging set. If family A 

generates enough credits to offset the negative credits of family B but not enough to 

also offset the negative credits of family C (and the manufacturer has no banked 

credits in the averaging set), the manufacturer may designate families A and B as 

having no deficit for the model year, provided it designates family C as having a 

deficit for the model year. 

(c) Your end-of-year and final reports must include the following additional information: 

(1) Show that your net balance of emission credits from all your participating vehicle 

families in each averaging set in the applicable model year is not negative (or is 

negative but, except as allowed under § 1037.745)..

(2) State whether you will reserve any emission credits for banking. 

(3) State that the report’s contents are accurate. 

(d) If you trade emission credits, you must send us a report within 90 days after the 

transaction, as follows: 

 (1) As the seller, you must include the following information in your report: 

(i) The corporate names of the buyer and any brokers. 

(ii) A copy of any contracts related to the trade. 

 (iii) The vehicle families that generated emission credits for the trade, including 

the number of emission credits from each family. 

(2) As the buyer, you must include the following information in your report: 

(i) The corporate names of the seller and any brokers. 

(ii) A copy of any contracts related to the trade. 

 (iii) How you intend to use the emission credits, including the number of emission 

credits you intend to apply to each vehicle family (if known). 

(e) Send your reports electronically to the Designated Compliance Officer using an 

approved information format. If you want to use a different format, send us a written 

request with justification for a waiver. 

(f) Correct errors in your end-of-year report or final report as follows: 

(1) You may correct any errors in your end-of-year report when you prepare the final 

report, as long as you send us the final report by the time it is due. 

(2) If you or we determine within 270 days after the end of the model year that errors 

mistakenly decreased your balance of emission credits, you may correct the errors 

and recalculate the balance of emission credits. You may not make these corrections 

for errors that are determined more than 270 days after the end of the model year. If 

you report a negative balance of emission credits, we may disallow corrections under 

this paragraph (f)(2). 

(3) If you or we determine anytime that errors mistakenly increased your balance of 

emission credits, you must correct the errors and recalculate the balance of emission 

credits. 

§ 1037.735 Recordkeeping.

(a) You must organize and maintain your records as described in this section. We may 

review your records at any time. 

(b) Keep the records required by this section for at least eight years after the due date for 
the end-of-year report. You may not use emission credits for any vehicles if you do not 

keep all the records required under this section. You must therefore keep these records to 

continue to bank valid credits. Store these records in any format and on any media, as 

long as you can promptly send us organized, written records in English if we ask for 

them. You must keep these records readily available. We may review them at any time. 

(c) Keep a copy of the reports we require in §§ 1037.725 and 1037.730. 

(d) Keep records of the vehicle identification number for each vehicle you produce that 

generates or uses emission credits under the ABT program. You may identify these 

numbers as a range. If you change the FEL after the start of production, identify the date 

you started using each FEL and the range of vehicle identification numbers associated 

with each FEL. You must also identify the purchaser and destination for each vehicle 

you produce to the extent this information is available. 

(e) We may require you to keep additional records or to send us relevant information not 

required by this section in accordance with the Clean Air Act. 

§ 1037.740 What restrictions applyRestrictions for using emission credits?.

The following restrictions apply for using emission credits: 

(a) Averaging sets. Except as specified in paragraph (b) of this section, emission credits 

may be exchanged only within an averaging set. There are three principal averaging sets 

for vehicles subject to this subpart. 

(1) Vehicles at or below 19,500 pounds GVWR that are subject to the standards of 

§1037.105. 

(2) Vvehicles above 19,500 pounds GVWR but at or below 33,000 pounds GVWR. 

(3) Vehicles over 33,000 pounds GVWR. 

(4) Note that other separate averaging sets also apply for emission credits not related 

to this subpart. For example, under § 1037.104, an additional averaging set 

comprises all vehicles subject to the standards of that section. Separate averaging sets 

also apply for engines under 40 CFR part 1036, including engines used in vehicles 

subject to this subpart. 

(b) Averaging between averaging sets. Credits generated from hybrid vehicles/engines

incorporating and other advanced technologies in a given. The averaging set may be 

used in other averaging sets under restrictions of paragraph (a) of this partsection do not 

apply for credits generated under §1037.104(d)(7), §1037.615 or 40 CFR part 1036.615 

from hybrid vehicles with regenerative braking, or from other advanced technologies. 

(1) The maximum amount of credits you may bring into an averaging set is 40the 

following service class groups is 60,000 Mg per model year.: 

(c) Applying credits to prior year deficits. Where your credit balance for the prior year is 

negative (i.e., there was a credit deficit) you may apply only credits that are surplus after 

meeting your current year credit obligations. 

(d) (i) Spark-ignition engines, light heavy-duty compression-ignition engines, and 

light heavy-duty vehicles. This group comprises the averaging set listed in 

paragraphs(a)(1) of this section and the averaging set listed in 40 CFR 

1036.740(a)(1) and (2).

(ii) Medium heavy-duty compression-ignition engines and medium heavy-duty 

vehicles. This group comprises the averaging sets listed in paragraph (a)(2) of this 

section and 40 CFR 1036.740(a)(3).
(iii) Heavy heavy-duty compression-ignition engines and heavy heavy-duty 

vehicles. This group comprises the averaging sets listed in paragraph (a)(3) of this 

section and 40 CFR 1036.740(a)(4).

(2) The limit specified in paragraph (b)(1) of this section does not limit the amount of 

advanced technology credits that can be used within a service class group if they were 

generated in that same service class group.

(c) Credit life. Credits expire after five years. 

(ed) Other restrictions. Other sections of this part specify additional restrictions for using 

emission credits under certain special provisions. 

§ 1037.745 End-of-year CO2 credit deficits. 

Except as allowed by this section, we may void the certificate of any vehicle family 

certified to an FEL above the applicable standard for which you do not have sufficient 

credits forby the model year when you submit your end-of-yeardeadline for submitting 

the final report is void. 

(a) Your certificate for a vehicle family for which you do not have sufficient CO2 credits 

will be not be void if you remedy the deficit with surplus credits within three model 

years. For example, if you have a credit deficit of 500 Mg for a vehicle family at the end 

of model year 2015, you must generate (or otherwise obtain) a surplus of at least 500 Mg 

in that same averaging set by the end of model year 2018. 

(b) You may apply only surplus credits to your deficit. You may not apply credits to a 

prior-year deficit from an earlier model year if they were generated in a model year for 

which any of your vehicle families for that averaging set had an end-of-year credit 

deficit. 

(c) If you do not remedy the deficit with surplus credits within three model years, we may

void your certificate is void for that vehicle family. Note that voiding a certificate applies 

ab initio (that is, retroactively).. Where the net deficit is less than the total amount of 

negative credits originally generated by the family, we will void the certificate only with 

respect to the number of vehicles needed to reach the amount of the net deficit. For 

example, if the original vehicle family generated 500 Mg of negative credits, and the 

manufacturer’s net deficit after three years was 250 Mg, we would void the certificate 

with respect to half of the vehicles in the family.

§ 1037.750 What can happen if I do not comply with the provisions of this subpart? 

(a) For each vehicle family participating in the ABT program, the certificate of 

conformity is conditionaled upon full compliance with the provisions of this subpart 

during and after the model year. You are responsible to establish to our satisfaction that 

you fully comply with applicable requirements. We may void the certificate of 

conformity for a vehicle family if you fail to comply with any provisions of this subpart. 

(b) You may certify your vehicle family or subfamily to an FEL above an applicable 

standard based on a projection that you will have enough emission credits to offset the 

deficit for the vehicle family. However, we may void the certificate of conformity See 

§1036.745 for provisions specifying what happens if you cannot show in your final report 

that you have enough actual emission credits to offset a deficit for any pollutant in a 

vehicle family and the deficit is not allowed under § 1037.745. 

(c) We may void the certificate of conformity for a vehicle family if you fail to keep 
records, send reports, or give us information we request. Note that failing to keep 

records, send reports, or give us information we request is also a violation of 42 U.S.C. 

7522(a)(2).

(d) You may ask for a hearing if we void your certificate under this section (see 

§ 1037.820). 

§ 1037.755 Information provided to the Department of Transportation. 

(a) We may require you to submit a pre-certification compliance report to us for the 

upcoming model year or the year after the upcoming model year.

(b) After receipt of each manufacturer’s final report as specified in § 1037.730 and 

completion of any verification testing required to validate the manufacturer’s submitted 

final data, we will issue a report to the Department of Transportation with CO2 emission 

information and will verify the accuracy of manufacturers’each manufacturer’s

equivalent fuel consumption data that is required to be reported by NHTSA inunder 49 

CFR 535.8. We will send a report to DOT for each vehicle manufacturer based on each 

regulatory category and subcategory, including sufficient information for NHTSA to 

determine fuel consumption and associated credit values. See 49 CFR 535.8 to determine 

if NHTSA deems submission of this information to EPA to also be a submission to 

NHTSA. 

Subpart I—Definitions and Other Reference Information 

§ 1037.801 Definitions. 

The following definitions apply to this part. The definitions apply to all subparts unless 

we note otherwise. All undefined terms have the meaning the Act gives to them. The 

definitions follow: 

 A to B testing means testing performed in pairs to allow comparison of vehicle A to 

vehicle B. 

 Act means the Clean Air Act, as amended, 42 U.S.C. 7401 - 7671q. 

 Adjustable parameter means any device, system, or element of design that someone 

can adjust (including those which are difficult to access) and that, if adjusted, may affect 

emissions or vehicle performance during emission testing or normal in-use 

operation.measured or modeled emissions (as applicable). You may ask us to exclude a 

parameter that is difficult to access if it cannot be adjusted to affect emissions without 

significantly degrading vehicle performance, or if you otherwise show us that it will not 

be adjusted in a way that affects emissions during in-use operation. 

 Adjusted Loaded Vehicle Weight means the numerical average of vehicle curb 

weight and GVWR. 

 Advanced technology means vehicle technology certified under §1037.611615, 

§1037.104(d)(7), or 40 CFR 1036.615. 

 Aftertreatment means relating to a catalytic converter, particulate filter, or any other 

system, component, or technology mounted downstream of the exhaust valve (or exhaust 

port) whose design function is to decrease emissions in the vehicle exhaust before it is 

exhausted to the environment. Exhaust-gas recirculation (EGR) and turbochargers are 

not aftertreatment. 

 Alcohol-fueled vehicle means a vehicle that is designed to run using an alcohol fuel. 
For purposes of this definition, alcohol fuels do not include fuels with a nominal alcohol 

content below 25 percent by volume. 

 Auxiliary emission control device means any element of design that senses 

temperature, motive speed, engine RPM, transmission gear, or any other parameter for 

the purpose of activating, modulating, delaying, or deactivating the operation of any part 

of the emission control system. 

 Averaging set has the meaning given in § 1037.701. 

B-pillar means the first vertical structure to the rear of the windshield or rear-most 

part of the driver’s seat, whichever is further to the rear. Note: the first vertical structure 

to the rear of the windshield is generally the structure of the body into which the driver’s 

door closes.

 Cab-complete vehicle means a vehicle that is first sold as an incomplete vehicle that 

substantially includes its cab. Vehicles known commercially as chassis-cabs, cabchassis, box-deletes, bed-deletes, cut-away vans are considered cab-complete vehicles. 

For purposes of this definition, a cab includes a steering column and passenger 

compartment. Note a vehicle lacking some components of the cab is a cab-complete 

vehicle if it substantially includes the cab. 

 Calibration means the set of specifications and tolerances specific to a particular 

design, version, or application of a component or assembly capable of functionally 

describing its operation over its working range. 

 Carbon-related exhaust emissions (CREE) has the meaning given in 40 CFR 600.002. 

Note that CREE represents the combined mass of carbon emitted as HC, CO, and CO2, 

expressed as having a molecular weight equal to that of CO2. 

 Carryover means relating to certification based on emission data generated from an 

earlier model year. 

 Certification means relating to the process of obtaining a certificate of conformity for 

a vehicle family that complies with the emission standards and requirements in this part. 

 Certified emission level means the highest deteriorated emission level in a vehicle 

family for a given pollutant from either transient or steady-state testing. 

 Class means relating to GVWR classes, as follows: 

(1) Class 2b means heavy-duty motor vehicles at or below 10,000 pounds GVWR. 

(2) Class 3 means heavy-duty motor vehicles above 10,000 pounds GVWR but at or 

below 14,000 pounds GVWR. 

(3) Class 4 means heavy-duty motor vehicles above 14,000 pounds GVWR but at or 

below 16,000 pounds GVWR. 

(4) Class 5 means heavy-duty motor vehicles above 16,000 pounds GVWR but at or 

below 19,500 pounds GVWR. 

(5) Class 6 means heavy-duty motor vehicles above 19,500 pounds GVWR but at or 

below 26,000 pounds GVWR. 

(6) Class 7 means heavy-duty motor vehicles above 26,000 pounds GVWR but at or 

below 33,000 pounds GVWR. 

(7) Class 8 means heavy-duty motor vehicles above 33,000 pounds GVWR. 

Complete vehicle has the meaning given in the definition of vehicle in this section. 

 Compression-ignition means relating to a type of reciprocating, internal-combustion 

engine that is not a spark-ignition engine. 

 Curb weight has the meaning given in 40 CFR 86.1803, consistent with the 
provisions of § 1037.140. 

 Date of manufacture means the date on which the certifying vehicle manufacturer 

completes its manufacturing operations, except as follows:

(1) Where the certificate holder is an engine manufacturer that does not manufacture the 

chassis, the date of manufacture of the vehicle is based on the date assembly of the 

vehicle is completed.

(2) We may approve an alternate date of manufacture based on the date on which the 

certifying (or primary) manufacturer completes assembly at the place of main assembly, 

consistent with the provisions of §1037.601 and 49 CFR 567.4.

 Day cab means a type of tractor cab that is not a sleeper cab. 

 Designated Compliance Officer means the Manager, Heavy-Duty and Nonroad 

Engine 

 Group (6405-J), U.S. Environmental Protection Agency, 1200 Pennsylvania Ave., NW., 

Washington, DC 20460. 

 Designated Enforcement Officer means the Director, Air Enforcement Division 

(2242A), U.S. Environmental Protection Agency, 1200 Pennsylvania Ave., NW., 

Washington, DC 20460. 

 Deteriorated emission level means the emission level that results from applying the 

appropriate deterioration factor to the official emission result of the emission-data 

vehicle. Note that where no deterioration factor applies, references in this part to the 

deteriorated emission level mean the official emission result. 

 Deterioration factor means the relationship between emissions at the end of useful life 

and emissions at the low-hour test point, expressed in one of the following ways: 

(1) For multiplicative deterioration factors, the ratio of emissions at the end of useful life 

to emissions at the low-hour test point. 

(2) For additive deterioration factors, the difference between emissions at the end of 

useful life and emissions at the low-hour test point. 

 Driver model means an automated controller that simulates a person driving a 

vehicle.

 Electric vehicle means a vehicle that does not include an engine, and is powered 

solely by an external source of electricity and/or solar power. Note that this does not 

include hybrid-electric hybrid or fuel-cell vehicles that use a chemical fuel such as 

gasoline, diesel fuel, or hydrogen. Electric vehicles may also be referred to as all-electric 

vehicles to distinguish them from hybrid-electric vehicles. 

 Emission control system means any device, system, or element of design that controls 

or reduces the emissions of regulated pollutants from a vehicle. 

 Emission-data vehicle means a vehicle that is tested for certification. This includes 

vehicle tested to establish deterioration factors. 

 Emission-related maintenance means maintenance that substantially affects emissions 

or is likely to substantially affect emission deterioration. 

 Excluded means relating to vehicles that are not subject to some or all of the 

requirements of this part as follows: 

(1) A vehicle that has been determined to not to be a motor vehicle is excluded from this 

part. 

(2) Certain vehicles are excluded from the requirements of this part under § 1037.5. 

(3) Specific regulatory provisions of this part may exclude a vehicle generally subject to 
this part from one or more specific standards or requirements of this part. 

 Exempted has the meaning given in 40 CFR 1068.30. 

 Family emission limit (FEL) means an emission level declared by the manufacturer to 

serve in place of an otherwise applicable emission standard under the ABT program in 

subpart H of this part. The family emission limit must be expressed to the same number 

of decimal places as the emission standard it replaces. Note that an FEL may apply as a 

“subfamily” emission limit. 

 Fuel system means all components involved in transporting, metering, and mixing the 

fuel from the fuel tank to the combustion chamber(s), including the fuel tank, fuel pump, 

fuel filters, fuel lines, carburetor or fuel-injection components, and all fuel-system vents. 

It also includes components for controlling evaporative emissions, such as fuel caps, 

purge valves, and carbon canisters. 

 Fuel type means a general category of fuels such as diesel fuel or natural gas. There 

can be multiple grades within a single fuel type, such as high-sulfur or low-sulfur diesel 

fuel. 

 Good engineering judgment has the meaning given in 40 CFR 1068.30. See 40 CFR 

1068.5 for the administrative process we use to evaluate good engineering judgment. 

 Gross vehicle weight rating (GVWR) means the value specified by the vehicle 

manufacturer as the maximum design loaded weight of a single vehicle, consistent with 

good engineering judgment. 

 Gross combination weight rating (GCWR) means the value specified by the vehicle 

manufacturer as the maximum weight of a loaded vehicle and trailer, consistent with 

good engineering judgment. For example, compliance with SAE J2807 is generally 

considered to be consistent with good engineering judgment, especially for Class 3 and 

smaller vehicles. 

Gross combined weight rating (GCWR) means the value specified by the vehicle 

manufacturer as the maximum weight of a loaded vehicle and trailer, consistent with 

good engineering judgment. For example, compliance with SAE J2807 is generally

considered to be consistent with good engineering judgment, especially for Class 3 and 

smaller vehicles.

 Heavy-duty engine means any engine used for (or for which the engine 

manufacturer could reasonably expect to be used for) motive power in a heavy-duty 

vehicle.

Heavy-duty engine means any engine used for (or for which the engine manufacturer 

could reasonably expect to be used for) motive power in a heavy-duty vehicle. Heavyduty vehicle means any motor vehicle above 8,500 pounds GVWR or that has a vehicle 

curb weight above 6,000 pounds or that has a basic vehicle frontal area greater than 45 

square feet. 

 Hybrid engine or hybrid powertrain means an engine or powertrain that includes 

energy storage features other than a conventional battery system or conventional 

flywheel. Supplemental electrical batteries and hydraulic accumulators are examples of 

hybrid energy storage systems Note that certain provisions in this part treat hybrid 

engines and powertrains intended for vehicles that include regenerative braking different 

than those intended for vehicles that do not include regenerative braking. 

 Hybrid vehicle means a vehicle that includes energy storage features (other than a 

conventional battery system or conventional flywheel) in addition to an internal 
combustion engine or other engine using consumable chemical fuel. Supplemental 

electrical batteries and hydraulic accumulators are examples of hybrid energy storage 

systems Note that certain provisions in this part treat hybrid vehicles that include 

regenerative braking different than those that do not include regenerative braking. 

 Hydrocarbon (HC) means the hydrocarbon group on which the emission standards are 

based for each fuel type. For alcohol-fueled vehicles, HC means nonmethane 

hydrocarbon equivalent (NMHCE) for exhaust emissions and total hydrocarbon 

equivalent (THCE) for evaporative emissions. For all other vehicles, HC means 

nonmethane hydrocarbon (NMHC) for exhaust emissions and total hydrocarbon (THC) 

for evaporative emissions. 

 Identification number means a unique specification (for example, a model

number/serial number combination) that allows someone to distinguish a particular 

vehicle from other similar vehicles. 

 Incomplete vehicle has the meaning given in the definition of vehicle in this section. 

 Innovative technology means technology certified under §1037.611610. 

 Light-duty truck means any motor vehicle rated at or below 8,500 pounds GVWR 

with a curb weight at or below 6,000 pounds and basic vehicle frontal area at or below 45 

square feet, which is: 

(1) Designed primarily for purposes of transportation of property or is a derivation of 

such a vehicle; or 

(2) Designed primarily for transportation of persons and has a capacity of more than 12 

persons; or 

(3) Available with special features enabling off-street or off-highway operation and use. 

 Light-duty vehicle means a passenger car or passenger car derivative capable of 

seating 12 or fewer passengers. 

 Low-mileage means relating to a vehicle with stabilized emissions and represents the 

undeteriorated emission level. This would generally involve approximately 4000 miles 

of operation. 

 Low rolling resistance tire means a tire on a vocational vehicle with a TRRL at or 

below of 7.7 kg/metric ton, a steer tire on a tractor with a TRRL at or below 7.7 kg/metric 

ton, or a drive tire on a tractor with a TRRL at or below 8.1 kg/metric ton.

 Manufacture means the physical and engineering process of designing, constructing, 

and/or assembling a vehicle. 

 Manufacturer has the meaning given in section 216(1) of the Act. In general, this 

term includes any person who manufactures a vehicle or vehicle for sale in the United 

States or otherwise introduces a new motor vehicle into commerce in the United States. 

This includes importers who import vehicles or vehicles for resale. 

 Medium-duty passenger vehicle (MDPV) has the meaning given in 40 CFR 86.1803.

 Model year means the manufacturer’s annual new model production period, except as 

restricted under this definition and 40 CFR part 85, subpart X. It must include January 1 

of the calendar year for which the model year is named, may not begin before January 2 

of the previous calendar year, and it must end by December 31 of the named calendar 

year. 

(1) The manufacturer who holds the certificate of conformity for the vehicle must 

assign the model year based on the date when its manufacturing operations are 

completed relative to its annual model year period. In unusual circumstances where 
completion of your assembly is delayed, we may allow you to assign a model year 

one year earlier, provided it does not affect which regulatory requirements will apply.

 (2) Unless a vehicle is being shipped to a secondary manufacturer that will hold the 

certificate of conformity, the model year must be assigned prior to introduction of the 

vehicle into U.S. commerce. The certifying manufacturer must redesignate the model 

year if it does not complete its manufacturing operations within the originally 

identified model year. A vehicle introduced into U.S. commerce without a model 

year is deemed to have a model year equal to the calendar year of its introduction into 

U.S. commerce unless the certifying manufacturer assigns a later date. 

 Motor vehicle has the meaning given in 40 CFR 85.1703. 

 New motor vehicle means a motor vehicle meeting the criteria of either paragraph (1) 

or (2) of this definition. New motor vehicles may be complete or incomplete. 

(1) A motor vehicle for which the ultimate purchaser has never received the equitable or 

legal title is a new motor vehicle. This kind of vehicle might commonly be thought of as 

"brand new" although a new motor vehicle may include previously used parts. Under 

this definition, the vehicle is new from the time it is produced until the ultimate purchaser 

receives the title or places it into service, whichever comes first. 

(2) An imported heavy-duty motor vehicle originally produced after the 1969 model year 

is a new motor vehicle. 

 Noncompliant vehicle means a vehicle that was originally covered by a certificate of 

conformity, but is not in the certified configuration or otherwise does not comply with the 

conditions of the certificate. 

 Nonconforming vehicle means a vehicle not covered by a certificate of conformity 

that would otherwise be subject to emission standards. 

 Nonmethane hydrocarbons (NMHC) means the sum of all hydrocarbon species 

except methane, as measured according to 40 CFR part 1065. 

 Official emission result means the measured emission rate for an emission-data 

vehicle on a given duty cycle before the application of any required deterioration factor, 

but after the applicability of regeneration adjustment factors. 

 Owners manual means a document or collection of documents prepared by the 

vehicle manufacturer for the owners or operators to describe appropriate vehicle 

maintenance, applicable warranties, and any other information related to operating or 

keeping the vehicle. The owners manual is typically provided to the ultimate purchaser 

at the time of sale. 

 Oxides of nitrogen has the meaning given in 40 CFR 1065.1001. 

 Particulate trap means a filtering device that is designed to physically trap all 

particulate matter above a certain size. 

 Percent has the meaning given in 40 CFR 1065.1001. Note that this means 

percentages identified in this part are assumed to be infinitely precise without regard to 

the number of significant figures. For example, one percent of 1,493 is 14.93.

 Placed into service means put into initial use for its intended purpose. 

 Power take-off (PTO) means a secondary engine shaft or other system on a vehicle(or 

equivalent) that provides substantial auxiliary power for purposes unrelated to vehicle 

propulsion or normal vehicle accessories such as air conditioning, power steering, and 

basic electrical accessories. A typical PTO uses a secondary shaft on the engine to 

transmit power to a hydraulic pump that powers auxiliary equipment, such as a boom on 
a bucket truck. You may ask us to consider other equivalent auxiliary power 

configurations (such as those with hybrid vehicles) as power take-off systems.

 Rechargeable Energy Storage System (RESS) means the component(s) of a hybrid 

engine or vehicle that store recovered energy for later use, such as the battery system in 

an electric hybrid vehicle. 

Regulatory sub-category means one of following groups: 

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

includes most gasoline-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 van. 

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

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

GVWR. 

(5) Vocational vehicles over 33,000 pounds GVWR. 

(6) Low and mid - -roof day cab tractors at or above 26,000 pounds GVWR but below 

33,000 pounds GVWR. 

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

GVWR. 

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

pounds GVWR. 

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

(10) Mid -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. 

(12) High roof day 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. 

 Relating to as used in this section means relating to something in a specific, direct 

manner. This expression is used in this section only to define terms as adjectives and not 

to broaden the meaning of the terms. 

 Revoke has the meaning given in 40 CFR 1068.30. 

 Roof height means the maximum height of a vehicle (rounded to the nearest inch), 

excluding narrow accessories such as exhaust pipes and antennas, but including any wide 

accessories such as roof fairings. Measure roof height of the vehicle configured to have 

its maximum height that will occur during actual use, with properly inflated tires and no 

driver, passengers, or cargo onboard. Roof height may also refer to the following 

categories: 

(1) Low-roof means relating to a vehicle with a roof height of 120 inches or less. 

(2) Mid-roof means relating to a vehicle with a roof height of 121 to 147 inches. 

(3) High-roof means relating to a vehicle with a roof height of 148 inches or more. 

 Round has the meaning given in 40 CFR 1065.1001. 

 Scheduled maintenance means adjusting, repairing, removing, disassembling, 

cleaning, or replacing components or systems periodically to keep a part or system from 

failing, malfunctioning, or wearing prematurely. It also may mean actions you expect are 

necessary to correct an overt indication of failure or malfunction for which periodic 
maintenance is not appropriate. 

 Sleeper cab means a type of tractor cab that has a compartment behind the driver’s 

seat intended to be used by the driver for sleeping. This includes cabs accessible from 

the driver’s compartment and those accessible from outside the vehicle. 

 Small manufacturer means a manufacturer meeting the criteria specified in 13 CFR 

121.201. For manufacturers owned by a parent company, the production limit applies to 

the production of the parent company and all its subsidiaries and the employee limit 

appliesand revenue limits apply to the total number of employees and total revenue of the 

parent company and all its subsidiaries. Spark-ignition means relating to a gasolinefueled engine or any other type of engine with a spark plug (or other sparking device) and 

with operating characteristics significantly similar to the theoretical Otto combustion 

cycle. Spark-ignition engines usually use a throttle to regulate intake air flow to control 

power during normal operation. 

 Standard payload means the vehicle payload assumed for each class in tons for 

modeling and calculating emission credits. There are three standard payloads:

(1) 2.85 tons for light heavy-duty vehicles.

(2) 5.6 tons for medium heavy-duty vehicles.

(3) 7.5 tons for heavy heavy-duty vehicles. 

 Standard trailer has the meaning given in § 1037.501. 

 Suspend has the meaning given in 40 CFR 1068.30. 

 Test sample means the collection of vehicles selected from the population of a vehicle 

family for emission testing. This may include testing for certification, production-line 

testing, or in-use testing. 

 Test vehicle means a vehicle in a test sample. 

 Test weight means the vehicle weight used or represented during testing. 

 Tire rolling resistance level (TRRL) means a value with units of kg/metric ton that 

represents that rolling resistance of a tire configuration. TRRLs are used as inputs to the 

GEM model under §1037.520. Note that a manufacturer may assign a value higher than 

the measured rolling resistance of a tire configuration. 

 Total hydrocarbon has the meaning given in 40 CFR 1065.1001. This generally 

means the combined mass of organic compounds measured by the specified procedure for 

measuring total hydrocarbon, expressed as a hydrocarbon with an atomic hydrogen-tocarbon ratio of 1.85:1. 

 Total hydrocarbon equivalent has the meaning given in 40 CFR 1065.1001. This 

generally means the sum of the carbon mass contributions of non-oxygenated 

hydrocarbons, alcohols and aldehydes, or other organic compounds that are measured 

separately as contained in a gas sample, expressed as exhaust hydrocarbon from 

petroleum-fueled vehicles. The atomic hydrogen-to-carbon ratio of the equivalent 

hydrocarbon is 1.85:1. 

 Tractor has the meaning given for “truck tractor” in 49 CFR 571.3. This includes 

most heavy-duty vehicles specifically designed for the primary purpose of pulling 

trailers, but does not include vehicles designed to carry other loads. For purposes of this 

definition “other loads” would not include loads carried in the cab, sleeper compartment, 

or toolboxes. Examples of vehicles that are similar to tractors but that are not tractors

under this part include dromedary tractors, automobile haulers, straight trucks with 

trailers hitches, and tow trucks. Note that the provisions of this part that apply for 
tractors do not apply for tractors that are classified as vocational tractors under 

§1037.630. 

 Ultimate purchaser means, with respect to any new vehicle, the first person who in 

good faith purchases such new vehicle for purposes other than resale. 

 United States has the meaning given in 40 CFR 1068.30. 

 Upcoming model year means for a vehicle family the model year after the one 

currently in production. 

 U.S.-directed production volume means the number of vehicle units, subject to the 

requirements of this part, produced by a manufacturer for which the manufacturer has a 

reasonable assurance that sale was or will be made to ultimate purchasers in the United 

States This does not include vehicles certified to state emission standards that are 

different than the emission standards in this part. 

 Useful life means the period during which a vehicle is required to comply with all 

applicable emission standards. 

 Vehicle means equipment intended for use on highways that meets the criteria of 

paragraph (1)(i) or (ii) of this definition, as follows: 

(1) The following equipment are vehicles: 

(i) A piece of equipment that is intended for self-propelled use on highways becomes 

a vehicle when it includes at least an engine, a transmission, and a frame. (Note: For 

purposes of this definition, any electrical, mechanical, and/or hydraulic devices 

attached to engines for the purpose of powering wheels are considered to be 

transmissions.) 

(ii) A piece of equipment that is intended for self-propelled use on highways becomes 

a vehicle when it includes a passenger compartment attached to a frame with axles. 

(2) Vehicles may be complete or incomplete vehicles as follows: 

(i) A complete vehicle is a functioning vehicle that has the primary load carrying 

device or container (or equivalent equipment) attached or a fully functional vehicle 

that is designed to pull a trailer. Examples of equivalent equipment would include 

fifth wheel trailer hitches, firefighting equipment, and utility booms. 

(ii) An incomplete vehicle is a vehicle that is not a complete vehicle when it is first 

sold as a vehicle and is not certified as a complete vehicle.. Incomplete vehicles may 

also be cab-complete vehicles. This may include vehicles sold to secondary vehicle 

manufacturers. Incomplete vehicles may also be cab-complete vehicles.

(iii) The primary use of the terms “complete vehicle” and “incomplete vehicle” are to 

distinguish whether a vehicle is complete when it is first sold as a vehicle.

(iv) You may ask us to allow you to certify a vehicle as incomplete if you 

manufacture the engines and sell the unassembled chassis components, as long as you 

do not produce and sell the body components necessary to complete the vehicle.

(3) Equipment such as trailers that are not self-propelled are not “vehicles” under this part 

1037, but may be considered part of a “motor vehicle”..

 Vehicle configuration means a unique combination of vehicle hardware and

calibration (related to measured or modeled emissions) within a vehicle family. Vehicles 

with hardware or software differences, but that have no hardware or software differences 

related to measured or modeled emissions may be included in the same vehicle 

configuration. Note that vehicles with hardware or software differences related to 

measured or modeled emissions are considered to be different configurations even if they 
have the same GEM inputs and FEL. Vehicles within a vehicle configuration differ only 

with respect to normal production variability or factors unrelated to measured or modeled 

emissions. 

 Vehicle family has the meaning given in § 1037.230. 

 Vehicle service class means a vehicle’s weight class as specified in this definition. 

Note that, while vehicle service class is similar to primary intended service class for 

engines, they are not necessarily the same. For example, a medium heavy-duty vehicle 

may include a light heavy-duty engine. Note also that while spark-ignition engines do 

not have a primary intended service class, vehicles using spark-ignition engines have a 

vehicle service class.

(1) Light heavy-duty vehicles are those vehicles with GVWR below 19,500 pounds. 

Vehicles In this class include heavy-duty pickup trucks and vans, motor homes and 

other recreational vehicles, and some straight trucks with a single rear axle. Typical 

applications would include personal transportation, light-load commercial delivery, 

passenger service, agriculture, and construction. 

(b2) Medium heavy-duty enginesvehicles are those vehicles with GVWR from 

19,500 to 33,000 pounds. Vehicles in this class include school buses, straight trucks 

with a single rear axle, city tractors, and a variety of special purpose vehicles such as 

small dump trucks, and refuse trucks. Typical applications would include commercial 

short haul and intra-city delivery and pickup. 

(c3) Heavy heavy-duty enginesvehicles are those vehicles with GVWR above 33,000 

pounds. Vehicles in this class include tractors, urban buses, and other heavy trucks. 

 Vehicle subfamily or subfamily means a subset of a vehicle family including vehicles 

subject to the same FEL(s). 

 Vocational means relating to a vehicle subject to the standards of § 1037.105 

(including vocational tractors). 

 Vocational tractor means a vehicle classified as a vocational tractor under §1037.630. 

 Void has the meaning given in 40 CFR 1068.30. 

 Volatile liquid fuel means any fuel other than diesel or biodiesel that is a liquid at 

atmospheric pressure and has a Reid Vapor Pressure higher than 2.0 pounds per square 

inch. 

 We (us, our) means the Administrator of the Environmental Protection Agency and 

any authorized representatives. 

§ 1037.805 Symbols, acronyms, and abbreviations. 

 The following symbols, acronyms, and abbreviations apply to this part: 

ABT Averaging, banking, and trading.

AECD auxiliary emission control device. 

CD drag coefficient.

CDA drag area.

CFD computational fluid dynamics.

CFR Code of Federal Regulations. 

CH4 methane. 

CO carbon monoxide. 

CO2 carbon dioxide. 

CREE carbon-related exhaust emissions. 

DF deterioration factor.

DOT Department of Transportation. 

EPA Environmental Protection Agency. 
ETW equivalent test weight.

FEL Family Emission Limit. 

g grams. 

GAWR gross axle weight rating.

GCWR gross combination weight rating.

GVWR gross vehicle weight rating.

GWP global-warming potential.

HC hydrocarbon. 

ISO International Organization for Standardization.

kg kilograms. 

m meter. 

mm millimeter

mph miles per hour. 

N2O nitrous oxide. 

NARA National Archives and Records Administration. 

NHTSA National Highway Transportation Safety Administration. 

NIST National Institute of Standards and Technology.

NMHC nonmethane hydrocarbons.

NMHCE nonmethane hydrocarbon equivalent.

NOx oxides of nitrogen (NO and NO2). 

NTE not-to-exceed.

PM particulate matter. 

RBMPTO resisting bending moment.power take-off.

RGWPRESS relative global-warming potential.rechargeable energy storage system.

RPM revolutions per minute. 

SAE Society of Automotive Engineers.

SEA Selective enforcement audit.

THC total hydrocarbon.

THCE total hydrocarbon equivalent.

TRUSKU transportation refrigerationStock-keeping unit. 

TRRL Tire rolling resistance level.

U.S.C. United States Code.

VINVSL vehicle identification numberspeed limiter. 

WF work factor. 

§ 1037.810 Incorporation by reference. 

(a) The documents referenced in this section have been Certain material is incorporated 

by reference ininto this part. The incorporation by reference was approved by with the 

approval of the Director of the Federal Register in accordance with under 5 U.S.C. 552(a) 

and 1 CFR part 51. Copies may be inspected at the U.S. Environmental Protection 

Agency, Office of Air and Radiation, 1200 Pennsylvania Ave., NW., Washington, DC 

20460, phone (202) 272–0167, or at the National Archives and Records Administration 

(NARA). For information on the availability of this material at NARA, call 202–741–

6030, or go to: 

http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html

and is available from the sources listed below:

(a) Certain material is incorporated by reference into this part with the approval of the 

Director of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. To enforce any 

edition other than that specified in this section, the Environmental Protection Agency 

must publish a notice of the change in the Federal Register and the material must be 

available to the public. All approved material is available for inspection at U.S. EPA, Air 

and Radiation Docket and Information Center, 1301 Constitution Ave., NW., Room 
B102, EPA West Building, Washington, DC 20460, (202) 202-1744, and is available 

from the sources listed below. It is also available for inspection at the National Archives 

and Records Administration (NARA). For information on the availability of this material 

at NARA, call 202–741–6030, or go to:

http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html

and is available from the sources listed below:.

(b) International Organization for Standardization, Case Postale 56, CH-1211 Geneva 

20, Switzerland, (41) 22749 0111, www.iso.org, or central@iso.org. 

(1) ISO /DIS–28580:2009 “INSERT TRR TITLE”;(E) “Passenger car, truck and bus 

tyres – Methods of measuring rolling resistance – Single point test and correlation of 

measurement results”, First Edition, July 1, 2009; IBR approved for § 1037.520(c). 

(2) [Reserved] 

(c) GEM ModelU.S. EPA has published the GEM computer model, Office of Air and 

Radiation, 2565 Plymouth Road, Ann Arbor, MI 48105, www.epa.gov/:

(1) GEM simulation tool, Version 2.0, [Insert signature date]; IBR approved for 

§ 1037.520. The computer code for this model is available as noted in paragraph (a) 

of this section. A working version of this software is also available for download at 

www.epa.gov. This IBR is approved for § 1037.520./otaq/climate/gemodel.htm. 

(2) [Reserved]

(d) SAE Material. The following material is available from the Society of Automotive 

Engineers. Copies of these materials may be obtained from Society of Automotive 

Engineers World Headquarters, 400 Commonwealth Dr., Warrendale, PA 15096–0001, 

phone (877) 606–7323 (U.S. and Canada) or (724) 776–4970 (outside the U.S. and 

Canada), or at http://www.sae.org. 

(1) SAE J1252, SAE Wind Tunnel Test Procedure for Trucks and Buses, Revised 

July 1981, IBR approved for § 1037.521(d), (e), and (f). 

(2) SAE J1594, Vehicle Aerodynamics Terminology, Revised July 2010, IBR 

approved for § 1037.521(d).

(3) SAE J2071, Aerodynamic Testing of Road Vehicles - Open Throat Wind Tunnel 

Adjustment, Revised June 1994, IBR approved for § 1037.521(d).

§ 1037.815 What provisions apply to confidential information??

The provisions of 40 CFR 1068.10 apply for information you consider confidential. 

§ 1037.820 Requesting a hearing..

(a) You may request a hearing under certain circumstances, as described elsewhere in this 

part. To do this, you must file a written request, including a description of your objection 

and any supporting data, within 30 days after we make a decision. 

(b) For a hearing you request under the provisions of this part, we will approve your 

request if we find that your request raises a substantial factual issue. 

(c) If we agree to hold a hearing, we will use the procedures specified in 40 CFR part 

1068, subpart G. 

§ 1037.825 Reporting and recordkeeping requirements. 

(a) This part includes various requirements to submit and record data or other 

information. Unless we specify otherwise, store required records in any format and on 
any media and keep them readily available for eight years after you send an associated 

application for certification, or eight years after you generate the data if they do not 

support an application for certification. You may not rely on anyone else to meet 

recordkeeping requirements on your behalf unless we specifically authorize it. We may 

review these records at any time. You must promptly send us organized, written records 

in English if we ask for them. We may require you to submit written records in an 

electronic format. 

(b) The regulations in § 1037.255, 40 CFR 1068.25, and 40 CFR 1068.101 describe your 

obligation to report truthful and complete information. This includes information not 

related to certification. Failing to properly report information and keep the records we 

specify violates 40 CFR 1068.101(a)(2), which may involve civil or criminal penalties. 

(c) Send all reports and requests for approval to the Designated Compliance Officer (see 

§ 1037.801). 

(d) Any written information we require you to send to or receive from another company 

is deemed to be a required record under this section. Such records are also deemed to be 

submissions to EPA. Keep these records for eight years unless the regulations specify a 

different period. We may require you to send us these records whether or not you are a 

certificate holder. 

(e) Under the Paperwork Reduction Act (44 U.S.C. 3501 et seq), the Office of 

Management and Budget approves the reporting and recordkeeping specified in the 

applicable regulations. The following items illustrate the kind of reporting and 

recordkeeping we require for vehicles regulated under this part: 

(1) We specify the following requirements related to vehicle certification in this part 

1037: 

(i) In subpart C of this part we identify a wide range of information required to 

certify vehicles. 

(ii) In subpart G of this part we identify several reporting and recordkeeping items 

for making demonstrations and getting approval related to various special 

compliance provisions. For example, equipment manufacturers must submit 

reports and keep records related to the flexibility provisions in § 1037.625.

(iii) In § 1037.725, 1037.730, and 1037.735 we specify certain records related to 

averaging, banking, and trading. 

(2) We specify the following requirements related to testing in 40 CFR part 1066: 

(i) In 40 CFR 1065.2 we give an overview of principles for reporting information. 

(ii) In 40 CFR 1065.10 and 1065.12 we specify information needs for establishing 

various changes to published test procedures. 

(iii) In 40 CFR 1065.25 we establish basic guidelines for storing test information. 

(iv) In 40 CFR 1065.695 we identify data that may be appropriate for collecting 

during testing of in-use vehicles using portable analyzers. 

Appendix I to part 1037 — Heavy-duty Transient Chassis Test Cycle 
Time Speed Speed 

sec. mph m/s 

1 0.00 0.00 

2 0.00 0.00 

3 0.00 0.00 

4 0.00 0.00 

5 0.00 0.00 

6 0.00 0.00 

7 0.41 0.18 

8 1.18 0.53 

9 2.26 1.01 

10 3.19 1.43 

11 3.97 1.77 

12 4.66 2.08 

13 5.32 2.38 

14 5.94 2.66 

15 6.48 2.90 

16 6.91 3.09 

17 7.28 3.25 

18 7.64 3.42 

19 8.02 3.59 

20 8.36 3.74 

21 8.60 3.84 

22 8.74 3.91 

23 8.82 3.94 

24 8.82 3.94 

25 8.76 3.92 

26 8.66 3.87 

27 8.58 3.84 

28 8.52 3.81 

29 8.46 3.78 

30 8.38 3.75 

31 8.31 3.71 

32 8.21 3.67 

33 8.11 3.63 

34 8.00 3.58 

35 7.94 3.55 

36 7.94 3.55 

37 7.80 3.49 

38 7.43 3.32 

39 6.79 3.04 

40 5.81 2.60 

41 4.65 2.08 

42 3.03 1.35 

43 1.88 0.84 

44 1.15 0.51 

45 1.14 0.51 

46 1.12 0.50 

47 1.11 0.50 

48 1.19 0.53 

49 1.57 0.70 

50 2.31 1.03 

51 3.37 1.51 

52 4.51 2.02 

53 5.56 2.49 

54 6.41 2.87 

55 7.09 3.17 

56 7.59 3.39 

57 7.99 3.57 

58 8.32 3.72 

59 8.64 3.86 

60 8.91 3.98 

61 9.13 4.08 

62 9.29 4.15 

63 9.40 4.20 

64 9.39 4.20 

65 9.20 4.11 

66 8.84 3.95 

67 8.35 3.73 

68 7.81 3.49 

69 7.22 3.23 

70 6.65 2.97 

71 6.13 2.74 

72 5.75 2.57 

73 5.61 2.51 

74 5.65 2.53 

75 5.80 2.59 

76 5.95 2.66 

77 6.09 2.72 

78 6.21 2.78 

79 6.31 2.82 

80 6.34 2.83 

81 6.47 2.89 

82 6.65 2.97 

83 6.88 3.08 

84 7.04 3.15 

85 7.05 3.15 

86 7.01 3.13 

87 6.90 3.08 

88 6.88 3.08 

89 6.89 3.08 

90 6.96 3.11 

91 7.04 3.15 

92 7.17 3.21 

93 7.29 3.26 

94 7.39 3.30 

95 7.48 3.34 

96 7.57 3.38 

97 7.61 3.40 

98 7.59 3.39 

99 7.53 3.37 

100 7.46 3.33 

101 7.40 3.31 

102 7.39 3.30 

103 7.38 3.30 

104 7.37 3.29 

105 7.37 3.29 

106 7.39 3.30 

107 7.42 3.32 

108 7.43 3.32 

109 7.40 3.31 

110 7.39 3.30 

111 7.42 3.32 

112 7.50 3.35 

113 7.57 3.38 

114 7.60 3.40 

115 7.60 3.40 

116 7.61 3.40 

117 7.64 3.42 

118 7.68 3.43 

119 7.74 3.46 

120 7.82 3.50 

121 7.90 3.53 

122 7.96 3.56 

123 7.99 3.57 

124 8.02 3.59 

125 8.01 3.58 

126 7.87 3.52 

127 7.59 3.39 

128 7.20 3.22 

129 6.52 2.91 

130 5.53 2.47 

131 4.36 1.95 

132 3.30 1.48 

133 2.50 1.12 

134 1.94 0.87 

135 1.56 0.70 

136 0.95 0.42 

137 0.42 0.19 

138 0.00 0.00 

Formatted Table
139 0.00 0.00 

140 0.00 0.00 

141 0.00 0.00 

142 0.00 0.00 

143 0.00 0.00 

144 0.00 0.00 

145 0.00 0.00 

146 0.00 0.00 

147 0.00 0.00 

148 0.00 0.00 

149 0.00 0.00 

150 0.00 0.00 

151 0.00 0.00 

152 0.00 0.00 

153 0.00 0.00 

154 0.00 0.00 

155 0.00 0.00 

156 0.00 0.00 

157 0.00 0.00 

158 0.00 0.00 

159 0.00 0.00 

160 0.00 0.00 

161 0.00 0.00 

162 0.00 0.00 

163 0.00 0.00 

164 0.00 0.00 

165 0.00 0.00 

166 0.00 0.00 

167 0.00 0.00 

168 0.00 0.00 

169 0.00 0.00 

170 0.00 0.00 

171 0.00 0.00 

172 1.11 0.50 

173 2.65 1.18 

174 4.45 1.99 

175 5.68 2.54 

176 6.75 3.02 

177 7.59 3.39 

178 7.75 3.46 

179 7.63 3.41 

180 7.67 3.43 

181 8.70 3.89 

182 10.20 4.56 

183 11.92 5.33 

184 12.84 5.74 

185 13.27 5.93 

186 13.38 5.98 

187 13.61 6.08 

188 14.15 6.33 

189 14.84 6.63 

190 16.49 7.37 

191 18.33 8.19 

192 20.36 9.10 

193 21.47 9.60 

194 22.35 9.99 

195 22.96 10.26 

196 23.46 10.49 

197 23.92 10.69 

198 24.42 10.92 

199 24.99 11.17 

200 25.91 11.58 

201 26.26 11.74 

202 26.38 11.79 

203 26.26 11.74 

204 26.49 11.84 

205 26.76 11.96 

206 27.07 12.10 

207 26.64 11.91 

208 25.99 11.62 

209 24.77 11.07 

210 24.04 10.75 

211 23.39 10.46 

212 22.73 10.16 

213 22.16 9.91 

214 21.66 9.68 

215 21.39 9.56 

216 21.43 9.58 

217 20.67 9.24 

218 17.98 8.04 

219 13.15 5.88 

220 7.71 3.45 

221 3.30 1.48 

222 0.88 0.39 

223 0.00 0.00 

224 0.00 0.00 

225 0.00 0.00 

226 0.00 0.00 

227 0.00 0.00 

228 0.00 0.00 

229 0.00 0.00 

230 0.00 0.00 

231 0.00 0.00 

232 0.00 0.00 

233 0.00 0.00 

234 0.00 0.00 

235 0.00 0.00 

236 0.00 0.00 

237 0.00 0.00 

238 0.00 0.00 

239 0.00 0.00 

240 0.00 0.00 

241 0.00 0.00 

242 0.00 0.00 

243 0.00 0.00 

244 0.00 0.00 

245 0.00 0.00 

246 0.00 0.00 

247 0.00 0.00 

248 0.00 0.00 

249 0.00 0.00 

250 0.00 0.00 

251 0.00 0.00 

252 0.00 0.00 

253 0.00 0.00 

254 0.00 0.00 

255 0.00 0.00 

256 0.00 0.00 

257 0.00 0.00 

258 0.00 0.00 

259 0.50 0.22 

260 1.57 0.70 

261 3.07 1.37 

262 4.57 2.04 

263 5.65 2.53 

264 6.95 3.11 

265 8.05 3.60 

266 9.13 4.08 

267 10.05 4.49 

268 11.62 5.19 

269 12.92 5.78 

270 13.84 6.19 

271 14.38 6.43 

272 15.64 6.99 

273 17.14 7.66 

274 18.21 8.14 

275 18.90 8.45 

276 19.44 8.69 

277 20.09 8.98 

278 21.89 9.79 

279 24.15 10.80 
280 26.26 11.74 

281 26.95 12.05 

282 27.03 12.08 

283 27.30 12.20 

284 28.10 12.56 

285 29.44 13.16 

286 30.78 13.76 

287 32.09 14.35 

288 33.24 14.86 

289 34.46 15.40 

290 35.42 15.83 

291 35.88 16.04 

292 36.03 16.11 

293 35.84 16.02 

294 35.65 15.94 

295 35.31 15.78 

296 35.19 15.73 

297 35.12 15.70 

298 35.12 15.70 

299 35.04 15.66 

300 35.08 15.68 

301 35.04 15.66 

302 35.34 15.80 

303 35.50 15.87 

304 35.77 15.99 

305 35.81 16.01 

306 35.92 16.06 

307 36.23 16.20 

308 36.42 16.28 

309 36.65 16.38 

310 36.26 16.21 

311 36.07 16.12 

312 35.84 16.02 

313 35.96 16.08 

314 36.00 16.09 

315 35.57 15.90 

316 35.00 15.65 

317 34.08 15.24 

318 33.39 14.93 

319 32.20 14.39 

320 30.32 13.55 

321 28.48 12.73 

322 26.95 12.05 

323 26.18 11.70 

324 25.38 11.35 

325 24.77 11.07 

326 23.46 10.49 

327 22.39 10.01 

328 20.97 9.37 

329 20.09 8.98 

330 18.90 8.45 

331 18.17 8.12 

332 16.48 7.37 

333 15.07 6.74 

334 12.23 5.47 

335 10.08 4.51 

336 7.71 3.45 

337 7.32 3.27 

338 8.63 3.86 

339 10.77 4.81 

340 12.65 5.66 

341 13.88 6.20 

342 15.03 6.72 

343 15.64 6.99 

344 16.99 7.60 

345 17.98 8.04 

346 19.13 8.55 

347 18.67 8.35 

348 18.25 8.16 

349 18.17 8.12 

350 18.40 8.23 

351 19.63 8.78 

352 20.32 9.08 

353 21.43 9.58 

354 21.47 9.60 

355 21.97 9.82 

356 22.27 9.96 

357 22.69 10.14 

358 23.15 10.35 

359 23.69 10.59 

360 23.96 10.71 

361 24.27 10.85 

362 24.34 10.88 

363 24.50 10.95 

364 24.42 10.92 

365 24.38 10.90 

366 24.31 10.87 

367 24.23 10.83 

368 24.69 11.04 

369 25.11 11.23 

370 25.53 11.41 

371 25.38 11.35 

372 24.58 10.99 

373 23.77 10.63 

374 23.54 10.52 

375 23.50 10.51 

376 24.15 10.80 

377 24.30 10.86 

378 24.15 10.80 

379 23.19 10.37 

380 22.50 10.06 

381 21.93 9.80 

382 21.85 9.77 

383 21.55 9.63 

384 21.89 9.79 

385 21.97 9.82 

386 21.97 9.82 

387 22.01 9.84 

388 21.85 9.77 

389 21.62 9.67 

390 21.62 9.67 

391 22.01 9.84 

392 22.81 10.20 

393 23.54 10.52 

394 24.38 10.90 

395 24.80 11.09 

396 24.61 11.00 

397 23.12 10.34 

398 21.62 9.67 

399 19.90 8.90 

400 18.86 8.43 

401 17.79 7.95 

402 17.25 7.71 

403 16.91 7.56 

404 16.75 7.49 

405 16.75 7.49 

406 16.87 7.54 

407 16.37 7.32 

408 16.37 7.32 

409 16.49 7.37 

410 17.21 7.69 

411 17.41 7.78 

412 17.37 7.77 

413 16.87 7.54 

414 16.72 7.47 

415 16.22 7.25 

416 15.76 7.05 

417 14.72 6.58 

418 13.69 6.12 

419 12.00 5.36 

420 10.43 4.66 
421 8.71 3.89 

422 7.44 3.33 

423 5.71 2.55 

424 4.22 1.89 

425 2.30 1.03 

426 1.00 0.45 

427 0.00 0.00 

428 0.61 0.27 

429 1.19 0.53 

430 1.61 0.72 

431 1.53 0.68 

432 2.34 1.05 

433 4.29 1.92 

434 7.25 3.24 

435 10.20 4.56 

436 12.46 5.57 

437 14.53 6.50 

438 16.22 7.25 

439 17.87 7.99 

440 19.74 8.82 

441 21.01 9.39 

442 22.23 9.94 

443 22.62 10.11 

444 23.61 10.55 

445 24.88 11.12 

446 26.15 11.69 

447 26.99 12.07 

448 27.56 12.32 

449 28.18 12.60 

450 28.94 12.94 

451 29.83 13.34 

452 30.78 13.76 

453 31.82 14.22 

454 32.78 14.65 

455 33.24 14.86 

456 33.47 14.96 

457 33.31 14.89 

458 33.08 14.79 

459 32.78 14.65 

460 32.39 14.48 

461 32.13 14.36 

462 31.82 14.22 

463 31.55 14.10 

464 31.25 13.97 

465 30.94 13.83 

466 30.71 13.73 

467 30.56 13.66 

468 30.79 13.76 

469 31.13 13.92 

470 31.55 14.10 

471 31.51 14.09 

472 31.47 14.07 

473 31.44 14.05 

474 31.51 14.09 

475 31.59 14.12 

476 31.67 14.16 

477 32.01 14.31 

478 32.63 14.59 

479 33.39 14.93 

480 34.31 15.34 

481 34.81 15.56 

482 34.20 15.29 

483 32.39 14.48 

484 30.29 13.54 

485 28.56 12.77 

486 26.45 11.82 

487 24.79 11.08 

488 23.12 10.34 

489 20.73 9.27 

490 18.33 8.19 

491 15.72 7.03 

492 13.11 5.86 

493 10.47 4.68 

494 7.82 3.50 

495 5.70 2.55 

496 3.57 1.60 

497 0.92 0.41 

498 0.00 0.00 

499 0.00 0.00 

500 0.00 0.00 

501 0.00 0.00 

502 0.00 0.00 

503 0.00 0.00 

504 0.00 0.00 

505 0.00 0.00 

506 0.00 0.00 

507 0.00 0.00 

508 0.00 0.00 

509 0.00 0.00 

510 0.00 0.00 

511 0.00 0.00 

512 0.00 0.00 

513 0.00 0.00 

514 0.00 0.00 

515 0.00 0.00 

516 0.00 0.00 

517 0.00 0.00 

518 0.00 0.00 

519 0.00 0.00 

520 0.00 0.00 

521 0.00 0.00 

522 0.50 0.22 

523 1.50 0.67 

524 3.00 1.34 

525 4.50 2.01 

526 5.80 2.59 

527 6.52 2.91 

528 6.75 3.02 

529 6.44 2.88 

530 6.17 2.76 

531 6.33 2.83 

532 6.71 3.00 

533 7.40 3.31 

534 7.67 3.43 

535 7.33 3.28 

536 6.71 3.00 

537 6.41 2.87 

538 6.60 2.95 

539 6.56 2.93 

540 5.94 2.66 

541 5.45 2.44 

542 5.87 2.62 

543 6.71 3.00 

544 7.56 3.38 

545 7.59 3.39 

546 7.63 3.41 

547 7.67 3.43 

548 7.67 3.43 

549 7.48 3.34 

550 7.29 3.26 

551 7.29 3.26 

552 7.40 3.31 

553 7.48 3.34 

554 7.52 3.36 

555 7.52 3.36 

556 7.48 3.34 

557 7.44 3.33 

558 7.28 3.25 

559 7.21 3.22 

560 7.09 3.17 

561 7.06 3.16 
562 7.29 3.26 

563 7.75 3.46 

564 8.55 3.82 

565 9.09 4.06 

566 10.04 4.49 

567 11.12 4.97 

568 12.46 5.57 

569 13.00 5.81 

570 14.26 6.37 

571 15.37 6.87 

572 17.02 7.61 

573 18.17 8.12 

574 19.21 8.59 

575 20.17 9.02 

576 20.66 9.24 

577 21.12 9.44 

578 21.43 9.58 

579 22.66 10.13 

580 23.92 10.69 

581 25.42 11.36 

582 25.53 11.41 

583 26.68 11.93 

584 28.14 12.58 

585 30.06 13.44 

586 30.94 13.83 

587 31.63 14.14 

588 32.36 14.47 

589 33.24 14.86 

590 33.66 15.05 

591 34.12 15.25 

592 35.92 16.06 

593 37.72 16.86 

594 39.26 17.55 

595 39.45 17.64 

596 39.83 17.81 

597 40.18 17.96 

598 40.48 18.10 

599 40.75 18.22 

600 41.02 18.34 

601 41.36 18.49 

602 41.79 18.68 

603 42.40 18.95 

604 42.82 19.14 

605 43.05 19.25 

606 43.09 19.26 

607 43.24 19.33 

608 43.59 19.49 

609 44.01 19.67 

610 44.35 19.83 

611 44.55 19.92 

612 44.82 20.04 

613 45.05 20.14 

614 45.31 20.26 

615 45.58 20.38 

616 46.00 20.56 

617 46.31 20.70 

618 46.54 20.81 

619 46.61 20.84 

620 46.92 20.98 

621 47.19 21.10 

622 47.46 21.22 

623 47.54 21.25 

624 47.54 21.25 

625 47.54 21.25 

626 47.50 21.23 

627 47.50 21.23 

628 47.50 21.23 

629 47.31 21.15 

630 47.04 21.03 

631 46.77 20.91 

632 45.54 20.36 

633 43.24 19.33 

634 41.52 18.56 

635 39.79 17.79 

636 38.07 17.02 

637 36.34 16.25 

638 34.04 15.22 

639 32.45 14.51 

640 30.86 13.80 

641 28.83 12.89 

642 26.45 11.82 

643 24.27 10.85 

644 22.04 9.85 

645 19.82 8.86 

646 17.04 7.62 

647 14.26 6.37 

648 11.52 5.15 

649 8.78 3.93 

650 7.17 3.21 

651 5.56 2.49 

652 3.72 1.66 

653 3.38 1.51 

654 3.11 1.39 

655 2.58 1.15 

656 1.66 0.74 

657 0.67 0.30 

658 0.00 0.00 

659 0.00 0.00 

660 0.00 0.00 

661 0.00 0.00 

662 0.00 0.00 

663 0.00 0.00 

664 0.00 0.00 

665 0.00 0.00 

666 0.00 0.00 

667 0.00 0.00 

668 0.00 0.00 
Appendix II to part 1037 — Power Take-Off Test Cycle 

Cycle 

Simulation 

Mode Start 

Time 

of 

Mode 

Normalized 

Pressure, Circuit 1 

(%) 

Normalized 

Pressure, Circuit 2 

(%) 

Utility 0 0 0.0 0.0 

Utility 1 33 80.5 0.0 

Utility 2 40 0.0 0.0 

Utility 3 145 83.5 0.0 

Utility 4 289 0.0 0.0 

Refuse 5 361 0.0 13.0 

Refuse 6 363 0.0 38.0 

Refuse 7 373 0.0 53.0 

Refuse 8 384 0.0 73.0 

Refuse 9 388 0.0 0.0 

Refuse 10 401 0.0 13.0 

Refuse 11 403 0.0 38.0 

Refuse 12 413 0.0 53.0 

Refuse 13 424 0.0 73.0 

Refuse 14 442 11.2 0.0 

Refuse 15 468 29.3 0.0 

Refuse 16 473 0.0 0.0 

Refuse 17 486 11.2 0.0 

Refuse 18 512 29.3 0.0 

Refuse 19 517 0.0 0.0 

Refuse 20 530 12.8 11.1 

Refuse 21 532 12.8 38.2 

Refuse 22 541 12.8 53.4 

Refuse 23 550 12.8 73.5 

Refuse 24 553 0.0 0.0 

Refuse 25 566 12.8 11.1 

Refuse 26 568 12.8 38.2 

Refuse 27 577 12.8 53.4 

Refuse 28 586 12.8 73.5 

Refuse 29 589 0.0 0.0 

Refuse 30 600 0.0 0.0 

 
PART 1068—GENERAL COMPLIANCE PROVISIONS FOR HIGHWAY, 

STATIONARY, AND NONROAD PROGRAMS

17. The authority citation for part 1068 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Appendix III to part 1037 —Emission Control Identifiers

This appendix identifies abbreviations for emission control information labels, as 

required under §1037.135.

Vehicle Speed Limiters

 -VSL – Vehicle speed limiter 

 -VSLS – “Soft-top” vehicle speed limiter

 -VSLE – Expiring vehicle speed limiter

 -VSLD – Vehicle speed limiter with both “soft-top” and expiration

Idle Reduction Technology 

 -IRT5 – Engine shutoff after 5 minutes or less of idling

-IRTE – Expiring engine shutoff

Tires

 -LRRA – Low rolling resistance tires (all)

 -LRRD – Low rolling resistance tires (drive)

 -LRRS – Low rolling resistance tires (steer)

Aerodynamic Components

 -ATS – Aerodynamic side skirt and/or fuel tank fairing

 -ARF – Aerodynamic roof fairing

 -ARFR – Adjustable height aerodynamic roof fairing

 -TGR – Gap reducing fairing (tractor to trailer gap)

Other Components

 -ADVH – Vehicle includes advanced hybrid technology components 

 -ADVO – Vehicle includes other advanced technology components (i.e., nonhybrid system)

 -INV – Vehicle includes innovative technology components

18.1. The heading of part 1068 is revised to read as set forth above.

Subpart A – [Amended]

19.1. Section 1068.1 is revised to read as follows:

§ 1068.1 Does this part apply to me?
(a) The provisions of this part apply to everyone with respect to the following engines 

and to equipment using the following engines (including owners, operators, parts 

manufacturers, and persons performing maintenance):

(1) Locomotives we regulate under 40 CFR part 1033.

(2) Heavy-duty motor vehicles and motor vehicle engines to the extent and in the 

manner specified in 40 CFR parts 85, 86, 1036 and 1037.

(3) Land-based nonroad compression-ignition engines we regulate under 40 CFR part 

1039.

(4) Stationary compression-ignition engines certified using the provisions of 40 CFR 

part 1039, as indicated in 40 CFR part 60, subpart IIII.

(5) Marine compression-ignition engines we regulate under 40 CFR part 1042.

(6) Marine spark-ignition engines we regulate under 40 CFR part 1045.

(7) Large nonroad spark-ignition engines we regulate under 40 CFR part 1048.

(8) Stationary spark-ignition engines certified using the provisions of 40 CFR parts 

1048 or 1054, as indicated in 40 CFR part 60, subpart JJJJ.

(9) Recreational engines and vehicles we regulate under 40 CFR part 1051 (such as 

snowmobiles and off-highway motorcycles).

(10) Small nonroad spark-ignition engines we regulate under 40 CFR part 1054.

(b) This part does not apply to any of the following engine or vehicle categories, except 

as specified in paragraph (d) of this section or as specified in other parts:

(1) Light-duty motor vehicles (see 40 CFR part 86).

(2) Highway motorcycles (see 40 CFR part 86).

(3) Aircraft engines (see 40 CFR part 87).

(4) Land-based nonroad compression-ignition engines we regulate under 40 CFR part 

89.

(5) Small nonroad spark-ignition engines we regulate under 40 CFR part 90.

(c) Paragraph (a) of this section identifies the parts of the CFR that define emission 

standards and other requirements for particular types of engines and equipment. This part 

1068 refers to each of these other parts generically as the “standard-setting part.” For 

example, 40 CFR part 1051 is always the standard-setting part for snowmobiles. Follow 

the provisions of the standard-setting part if they are different than any of the provisions 

in this part.

(d) Specific provisions in this part 1068 start to apply separate from the schedule for 

certifying engines to new emission standards, as follows:

(1) The provisions of §§ 1068.30 and 1068.310 apply for stationary spark-ignition 

engines built on or after January 1, 2004, and for stationary compression-ignition 

engines built on or after January 1, 2006.

(2) The provisions of §§ 1068.30 and 1068.235 apply for the types of 

engines/equipment listed in paragraph (a) of this section beginning January 1, 2004, if 

they are used solely for competition.

Subpart C – [Amended]Section 1068.210 is revised to read as follows:§1068.210 

What are the provisions for exempting test engines/equipment?

(a) We may exempt engines/equipment that you will use for research, investigations, 

studies, demonstrations, or training. Note that you are not required to get an exemption 
under this section for engines that are exempted under other provisions of this part, such 

as the manufacturer-owned exemption in §1068.215.

(b) Anyone may ask for a testing exemption. 

(c) If you are a certificate holder, you may request an exemption for engines/equipment 

you intend to include in test programs over a two-year period. 

(1) In your request, tell us the maximum number of engines/equipment involved and 

describe how you will make sure exempted engines/equipment are used only for this 

testing. For example, if the exemption will involve other companies using your 

engines/equipment, describe your plans to track individual units so you can properly 

report on their final disposition. 

(2) Give us the information described in paragraph (d) of this section if we ask for it.

(d) If you are not a certificate holder, do all the following things: 

(1) Show that the proposed test program has a valid purpose under paragraph (a) of 

this section.

(2) Show you need an exemption to achieve the purpose of the test program (time 

constraints may be a basis for needing an exemption, but the cost of certification 

alone is not).

(3) Estimate the duration of the proposed test program and the number of 

engines/equipment involved.

(4) Allow us to monitor the testing.

(5) Describe how you will ensure that you stay within this exemption’s purposes. 

Address at least the following things:

(i) The technical nature of the test.

(ii) The test site.

(iii) The duration and accumulated engine/equipment operation associated with 

the test.

(iv) Ownership and control of the engines/equipment involved in the test.

(v) The intended final disposition of the engines/equipment.

(vi) How you will identify, record, and make available the engine/equipment 

identification numbers.

(vii) The means or procedure for recording test results.

(e) If we approve your request for a testing exemption, we will send you a letter or a 

memorandum describing the basis and scope of the exemption. It will also include any 

necessary terms and conditions, which normally require you to do the following:

(1) Stay within the scope of the exemption.

(2) Create and maintain adequate records that we may inspect.

(3) Add a permanent label to all engines/equipment exempted under this section, 

consistent with §1068.45, with at least the following items: 

(i) The label heading "EMISSION CONTROL INFORMATION".

(ii) Your corporate name and trademark.

(iii) Engine displacement, family identification, and model year of the 

engine/equipment (as applicable), or whom to contact for further information.

(iv) One of these statements (as applicable):

(A) “THIS ENGINE IS EXEMPT UNDER 40 CFR 1068.210 OR 1068.215 

FROM EMISSION STANDARDS AND RELATED REQUIREMENTS.” 
(B) “THIS EQUIPMENT IS EXEMPT UNDER 40 CFR 1068.210 OR 

1068.215 FROM EMISSION STANDARDS AND RELATED 

REQUIREMENTS.”

(4) Tell us when the test program is finished.

(5) Tell us the final disposition of the engines/equipment.

(6) Send us a written confirmation that you meet the terms and conditions of this 

exemption.

20.1. Section 1068.235 is revised to read as follows:

§ 1068.235 What are the provisions for exempting engines/equipment used solely 

for competition?

(a) New engines/equipment you produce that are used solely for competition are 

generally excluded from emission standards. See the standard-setting parts for specific 

provisions where applicable.

(b) If you modify any nonroad engines/equipment after they have been placed into 

service in the United States so they will be used solely for competition, they are exempt 

without request. This exemption applies only to the prohibition in §1068.101(b)(1) and is 

valid only as long as the engine/equipment is used solely for competition. You may not 

use the provisions of this paragraph (b) to circumvent the requirements that apply to the 

sale of new competition engines under the standard-setting part.

(c) If you modify any nonroad engines/equipment under paragraph (b) of this section, you 

must destroy the original emission labels. If you loan, lease, sell, or give any of these 

engines/equipment to someone else, you must tell the new owner (or operator, if 

applicable) in writing that they may be used only for competition.

Subpart D – [Amended]

Section 1068.325 is revised to read as follows:§1068.325 What are the temporary 

exemptions for imported engines/equipment?

You may import engines/equipment under certain temporary exemptions, subject to the 

conditions in this section. We may ask U.S. Customs and Border Protection to require a 

specific bond amount to make sure you comply with the requirements of this subpart. 

You may not sell or lease one of these engines/equipment while it is in the United States 

except as specified in this section or §1068.201(i). You must eventually export the 

engine/equipment as we describe in this section unless it conforms to a certificate of 

conformity or it qualifies for one of the permanent exemptions in §1068.315. 

(a) Exemption for repairs or alterations. You may temporarily import nonconforming 

engines/equipment under bond solely for repair or alteration, subject to our advance 

approval as described in paragraph (j) of this section. You may operate the 

engine/equipment in the United States only as necessary to repair it, alter it, or ship it to 

or from the service location. Export the engine/equipment directly after servicing is

complete.

(b) Testing exemption. You may temporarily import nonconforming engines/equipment 

under bond for testing if you follow the requirements of §1068.210, subject to our 
advance approval as described in paragraph (j) of this section. You may operate the 

engines/equipment in the United States only as needed to perform tests. This exemption 

expires one year after you import the engine/equipment unless we approve an extension. 

The engine/equipment must be exported before the exemption expires. You may sell or 

lease the engines/equipment consistent with the provisions of §1068.210.

(c) Display exemption. You may temporarily import nonconforming engines/equipment 

under bond for display if you follow the requirements of§1068.220, subject to our 

advance approval as described in paragraph (j) of this section. This exemption expires 

one year after you import the engine/equipment, unless we approve your request for an 

extension. We may approve an extension of up to one more year for each request, but no 

more than three years total. The engine/equipment must be exported by the time the 

exemption expires or directly after the display concludes, whichever comes first. 

(d) Export exemption. You may temporarily import nonconforming engines/equipment 

to export them, as described in §1068.230. You may operate the engine/equipment in the 

United States only as needed to prepare it for export. Label the engine/equipment as 

described in §1068.230. You may sell or lease the engines/equipment for operation 

outside the United States consistent with the provisions of §1068.230.

(e) Diplomatic or military exemption. You may temporarily import nonconforming 

engines/equipment without bond if you represent a foreign government in a diplomatic or 

military capacity. In your request to the Designated Compliance Officer (see §1068.305), 

include either written confirmation from the U.S. State Department that you qualify for 

this exemption or a copy of your orders for military duty in the United States. We will 

rely on the State Department or your military orders to determine when your diplomatic 

or military status expires, at which time you must export your exempt engines/equipment.

(f) Delegated-assembly exemption. You may import a nonconforming engine for final 

assembly under the provisions of §1068.261. You may sell or lease the 

engines/equipment consistent with the provisions of §1068.261.

(g) Exemption for partially complete engines. You may import an engine if another 

company already has a certificate of conformity and will be modifying the engine to be in 

its final certified configuration or a final exempt configuration under the provisions of 

§1068.262. You may also import a partially complete engine by shipping it from one of 

your facilities to another under the provisions of §1068.260(c). If you are importing a 

used engine that becomes new as a result of importation, you must meet all the 

requirements that apply to original engine manufacturers under §1068.262. You may sell 

or lease the engines consistent with the provisions of §1068.262.

(h) [Reserved]

(i) [Reserved]

(j) Approvals. For the exemptions in this section requiring our approval, you must send a 

request to the Designated Compliance Officer before importing the engines/equipment. 

We will approve your request if you meet all the applicable requirements and conditions. 

If another section separately requires that you request approval for the exemption, you 

may combine the information requirements in a single request. Include the following 

information in your request:

(1) Identify the importer of the engine/equipment and the applicable postal address, email address, and telephone number.
(2) Identify the engine/equipment owner and the applicable postal address, e-mail 

address, and telephone number.

(3) Identify the engine/equipment by model number (or name), serial number, and 

original production year.

(4) Identify the specific regulatory provision under which you are seeking an 

exemption.

(5) Authorize EPA enforcement officers to conduct inspections or testing as allowed 

under the Clean Air Act.

(6) Include any additional information we specify for demonstrating that you qualify for 

the exemption.PART 1039— CONTROL OF EMISSIONS FROM NEW AND INUSE NONROAD COMPRESSION-IGNITION ENGINES 

21.33. The authority citation for part 1039 continues to read as follows: 

Authority: 42 U.S.C. 7401-7671q. 

Subpart F—[Amended] 

22.34. Section 1039.510 is amended by revising paragraph (b) before the equation to 

read as follows: 

§1039.510 Which duty cycles do I use for transient testing? 

* * * * * 

(b) The transient test sequence consists of an initial run through the transient duty cycle 

from a cold start, 20 minutes with no engine operation, then a final run through the same 

transient duty cycle. Calculate the official transient emission result from the following 

equation: 

* * * * * 

PART 1065—ENGINE-TESTING PROCEDURES 

23.35. The authority citation for part 1065 continues to read as follows: 

Authority: 42 U.S.C. 7401-7671q. 

Subpart A—[Amended] 

24.36. Section 1065.1 is amended by adding paragraph (h) to read as follows: 

§1065.1 Applicability. 

* * * * * 

(h) 40 CFR part 1066 describes how to measure emissions from vehicles that are subject 

to standards in g/mile or g/kilometer. Those vehicle testing provisions extensively 

reference portions of this part 1065. See 40 CFR part 1066 and the standard-setting part 

for additional information. 

25.37. Section 1065.15 is amended by revising paragraph (e) to read as follows: 

§1065.15 Overview of procedures for laboratory and field testing. 

* * * * * 
(e) The following figure illustrates the allowed measurement configurations described in 

this part 1065: 

 
Figure 1 of §1065.15—Default test procedures and other specified procedures. 

 

Power

Continuous Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake- specific Emissions for

Transient Duty Cycle Testing

Emissions Rate Total Work

Raw Gaseous 

Default procedures

Other specified procedures

Alternate procedure

approval required

Alternate procedure

approval required for PM

Power

Continuous Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake- specific Emissions for

Transient Duty Cycle Testing

Emissions Rate Total Work

Raw Gaseous 

Default procedures

Other specified procedures

Alternate procedure 

approval required for PM

Power

Continuous Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake- specific Emissions for

Transient Duty Cycle Testing

Emissions Rate Total Work

Raw Gaseous 

Default procedures

Other specified procedures

Alternate procedure

approval required

Alternate procedure

approval required for PM

Power

Continuous Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake- specific Emissions for

Transient Duty Cycle Testing

Emissions Rate Total Work

Raw Gaseous 

Default procedures

Other specified procedures

Alternate procedure 

approval required for PM

Power

Continuous

Raw Gaseous 

Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake-specific Emissions for

Steady-state Duty Cycle Testing

Emissions Rate Total Work

Default procedures

Other specified procedures

Alternate procedure

approval required

Power

Continuous

Raw Gaseous 

Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake-specific Emissions for

Steady-state Duty Cycle Testing

Emissions Rate Total Work

Default procedures

Other specified procedures

Power

Continuous

Raw Gaseous 

Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake-specific Emissions for

Steady-state Duty Cycle Testing

Emissions Rate Total Work

Default procedures

Other specified procedures

Alternate procedure

approval required

Power

Continuous

Raw Gaseous 

Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake-specific Emissions for

Steady-state Duty Cycle Testing

Emissions Rate Total Work

Default procedures

Other specified procedures

Power

Continuous Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake- specific Emissions for

Field Testing

Emissions Rate Total Work

Raw Gaseous 

Default procedures

Other specified procedures

Alternate procedure

approval required

Power

Continuous Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake- specific Emissions for

Field Testing

Emissions Rate Total Work

Raw Gaseous 

Default procedures

Other specified procedures

Power

Continuous Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake- specific Emissions for

Field Testing

Emissions Rate Total Work

Raw Gaseous 

Default procedures

Other specified procedures

Alternate procedure

approval required

Power

Continuous Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake- specific Emissions for

Field Testing

Emissions Rate Total Work

Raw Gaseous 

Default procedures

Other specified procedures
Power

Continuous Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake- specific Emissions for

Field Testing

Emissions Rate Total Work

Raw Gaseous 

Default procedures

Other specified procedures

Alternate procedure

approval required

Power

Continuous Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake- specific Emissions for

Field Testing

Emissions Rate Total Work

Raw Gaseous 

Default procedures

Other specified procedures

Power

Continuous Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake- specific Emissions for

Field Testing

Emissions Rate Total Work

Raw Gaseous 

Default procedures

Other specified procedures

Alternate procedure

approval required

Power

Continuous Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake- specific Emissions for

Field Testing

Emissions Rate Total Work

Raw Gaseous 

Default procedures

Other specified procedures

Power

Continuous

Raw Gaseous 

Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake-specific Emissions for

Steady-state Duty Cycle Testing

Emissions Rate Total Work

Default procedures

Other specified procedures

Alternate procedure

approval required

Power

Continuous

Raw Gaseous 

Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake-specific Emissions for

Steady-state Duty Cycle Testing

Emissions Rate Total Work

Default procedures

Other specified procedures

Power

Continuous

Raw Gaseous 

Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake-specific Emissions for

Steady-state Duty Cycle Testing

Emissions Rate Total Work

Default procedures

Other specified procedures

Alternate procedure

approval required

Power

Continuous

Raw Gaseous 

Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake-specific Emissions for

Steady-state Duty Cycle Testing

Emissions Rate Total Work

Default procedures

Other specified procedures

Power

Continuous Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake- specific Emissions for

Transient Duty Cycle Testing

Emissions Rate Total Work

Raw Gaseous 

Default procedures

Other specified procedures

Alternate procedure

approval required

Alternate procedure

approval required for PM

Power

Continuous Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake- specific Emissions for

Transient Duty Cycle Testing

Emissions Rate Total Work

Raw Gaseous 

Default procedures

Other specified procedures

Alternate procedure 

approval required for PM

Power

Continuous Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake- specific Emissions for

Transient Duty Cycle Testing

Emissions Rate Total Work

Raw Gaseous 

Default procedures

Other specified procedures

Alternate procedure

approval required

Alternate procedure

approval required for PM

Power

Continuous Fuel

& BSFC 

Torque

& Speed 

Total Emissions

Batch 

Constant

Dilution Ratio

Partial Flow 

Dilute 

Varying

Dilution Ratio

Full Flow 

Brake- specific Emissions for

Transient Duty Cycle Testing

Emissions Rate Total Work

Raw Gaseous 

Default procedures

Other specified procedures

Alternate procedure 

approval required for PM
38. Section 10391065.20 is amended by revising paragraphs (a) introductory text, (a)(1), 

and (e) to read as follows: 

§1065.20 Units of measure and overview of calculations. 

(a) System of units. The procedures in this part generally follow the International System 

of Units (SI), as detailed in NIST Special Publication 811, “Guide for the Use of the 

International System of Units (SI),” which we incorporate by reference in §1065.1010. 

This document is available on the Internet at 

http://physics.nist.gov/Pubs/SP811/contents.html. The following exceptions apply: 

(1) We designate angular speedrotational frequencyspeed, fn, of an engine’s crankshaft in 

revolutions per minute (revr/min), rather than the SI unit of reciprocal radians per 

seconds (1radsecond (rad/s). This is based on the commonplace use of revr/min in many 

engine dynamometer laboratories. Also, we use the symbol fn to identify rotational 

frequency in rev/min, rather than the SI convention of using n. This avoids confusion 

with our usage of the symbol n for a molar quantity.

* * * * *

(b) * * * 

(e) Rounding. You are required to round certain final values, such as final emission 

values. You may round intermediate values when transferring data as long as you 

maintain at least six significant digits (which requires more than six decimal places for 

values less than 0.1), or all significant digits if fewer than six digits are available. Unless 

the standard-setting part specifies otherwise, round only final values, do not round other 

intermediate values. Round values to the number of significant digits necessary to match 

the number of decimal places of the applicable standard or specification as described in 

this paragraph (e). For information not related to standards orNote that specifications, 

use good engineering judgment to record the appropriate number expressed as 

percentages have infinite precision (as described in paragraph (e)(7) of significant digits.

this section). Use the following rounding convention, which is consistent with ASTM 

E29 and NIST SP 811 and ASTM E29 (incorporated by reference in §1065.1010): 

(1) If the first (left-most) digit to be removed is less than five, remove all the appropriate 

digits without changing the digits that remain. For example, 3.141593 rounded to the 

second decimal place is 3.14. 

(2) If the first digit to be removed is greater than five, remove all the appropriate digits 

and increase the lowest-value remaining digit by one. For example, 3.141593 rounded to 

the fourth decimal place is 3.1416. 

(3) If the first digit to be removed is five with at least one additional non-zero digit 

following the five, remove all the appropriate digits and increase the lowest-value 

remaining digit by one. For example, 3.141593 rounded to the third decimal place is 

3.142. 

(4) If the first digit to be removed is five with no additional non-zero digits following the 

five, remove all the appropriate digits, then increase the lowest-value remaining digit by 

one if it is odd and leave it unchanged if it is even. For example, 1.75 and 1.750 rounded 

to the first decimal place are 1.8; while 1.85 and 1.850 rounded to the first decimal place 

are also 1.8. Note that this rounding procedure will always result in an even number for 

the lowest-value digit. 

(5) This paragraph (e)(5) applies if the regulation specifies rounding to somethingan 

increment other than decimal places or powers of ten (to the nearest 0.01, 0.1, 1, 10, 100, 
etc.). To round numbers for these special cases, divide the quantity by the specified 

rounding increment. Round the result to the nearest whole number as described in 

paragraphs (e)(1) through (4) of this section. Multiply the rounded number by the 

specified rounding increment. This value is the desired result. For example, to round 

0.90 to the nearest 0.2, divide 0.90 by 0.2 to get a result of 4.5, which rounds to 4. 

Multiplying 4 by 0.2 gives 0.8, which is the result of rounding 0.90 to the nearest 0.2. 

(6) The following tables further illustrate the rounding procedures specified in this 

paragraph (e): 

Quantity 

Rounding Increment 

10 1 0.1 0.01 

3.141593 0 3 3.1 3.14 

123,456.789 123,460 123,457 123,456.8 123,456.79 

5.500 10 6 5.5 5.50 

4.500 0 4 4.5 4.50 

Quantity 

Rounding Increment 

25 3 0.5 0.02 

229.267 225 228 229.5 229.26 

62.500 50 63 62.5 62.50 

87.500 100 87 87.5 87.50 

7.500 0 6 7.5 7.50 

(7)(i) ) This paragraph (e)(7) applies where we specify a parameterlimit or tolerance as 

some percentage of another value; divide (such as ±2 % of a maximum concentration). 

You may show compliance with such specifications either by applying the parameter 

bypercentage to the othertotal value; determine the final value to calculate an absolute 

limit, or by rounding converting the absolute value to a percentage by dividing it by the 

quotient as described in this paragraph (e) assuming total value. 

(i) Do not round either value (the specifiedabsolute limit or the calculated percentage has 

infinite precision,), except as specified in paragraph (e)(7)(ii) of this section. Compare 

the final value to the specification. For example, in the linearity verification, the upper 

limit on the SEE parameter is specified as a percentage of the maximum input value. 

Forassume we specify that an analyzer must have a repeatability of ±1 % of the 

maximum concentration or better, the maximum concentration is 1059 ppm, and you 

determine repeatability to be ±6.3 ppm. In this example, if both the SEE and maximum 

value have three significant figures, divide the SEE by the maximum value and round the 

result to three significant figures. Compare the rounded value to the specified percentage 

(expressed to the same number of decimal places as the rounded value, by adding 

zerosyou could calculate an absolute limit of ±10.59 ppm (1059 ppm × 0.01) or calculate 

that the 6.3 ppm repeatability is equivalent to the right of the percentage as necessary) to 

determine compliance with this specification.a repeatability of 0.5949008498584 %.

(ii) Prior to July 1, 2013, you may treat tolerances (and equivalent specifications) 

specified in percentages as having fixed rather than infinite precision. For example, 2 % 

would be equivalent to 1.51 % to 2.50 % and 2.0 % would be equivalent to 1.951 % to 

2.050 %. 
(8) You may use measurement devices that incorporate internal rounding, consistent with 

the provisions of this paragraph (e)(8). You may use devices that use any rounding 

convention if they report six or more digits. You may use devices that report fewer than 

six digits, consistent with good engineering judgment and the accuracy, repeatability, and

noise specifications of this part. Note that this provision does not necessarily require you 

to perform engineering analysis or keep records.

* * * * * 

Subpart B—[Amended] 

39. Section 1065.125 is amended by revising paragraph (e)(1) introductory text to read 

as follows: 

§1065.125 Engine intake air. 

* * * * * 

(e) * * * 

(1) Use a charge-air cooling system with a total intake-air capacity that represents 

production engines’ in-use installation. Design any laboratory charge-air cooling system 

to minimize accumulation of condensate. Drain any accumulated condensate. Before 

starting a duty cycle (or preconditioning for a duty cycle) and), completely close all 

drains except those drains representative of drainsthat would normally openbe closed

during in-use operation before starting a duty cycle.. Keep those drains closed during the 

emission test (this does not apply to drains normally open during in-use operation).. 

Maintain coolant conditions as follows: 

(i) * * *

* * * * *

40. Section 1065.140 is amended by revising paragraphs (c)(6)(ii)(C) and (D) to read as 

follows:

§1065.140 Dilution for gaseous and PM constituents.

* * * * *

(c) * * *

(6) * * *

(ii) * * *

(C) Identify the maximum potential mole fraction of dilute exhaust lost on a continuous 

basis during the entire test interval. This value must be less than or equal to 0.02. 

Calculate on a continuous basis the mole fraction of water that would be in equilibrium 

with liquid water at the measured minimum surface temperature. Subtract this mole 

fraction from the mole fraction of water that would be in the exhaust without 

condensation (either measured or from the chemical balance), and set any negative values 

to zero. This difference is the potential mole fraction of the dilute exhaust that would be 

lost due to water condensation on a continuous basis. 

(D) Integrate the product of the molar flow rate of the dilute exhaust and the potential 

mole fraction of dilute exhaust lost, and divide by the totalized dilute exhaust molar flow 

over the test interval. This is the potential mole fraction of the dilute exhaust that would 

be lost due to water condensation over the entire test interval. Note that this assumes no 

re-evaporation. This value must be less than or equal to 0.005.
* * * * * 

40.41.Section 1065.170 is amended by revising paragraph (c)(1)(vi) to read as follows: 

§1065.170 Batch sampling for gaseous and PM constituents. 

* * * * * 

(c) * * * 

(1) * * * 

(vi) Maintain a filter face velocity near 100 cm/s with less than 5% of the recorded flow 

values exceeding 100 cm/s, unless you expect either the net PM mass on the filter to 

exceed 400 μg, assuming a 38 mm diameter filter stain area. Measure face velocity as 

the volumetric flow rate of the sample at the pressure upstream of the filter and 

temperature of the filter face as measured in §1065.140(e), divided by the filter's exposed 

area. You may use the exhaust stack or CVS tunnel pressure for the upstream pressure if 

the pressure drop through the PM sampler up to the filter is less than 2 kPa. 

* * * * * 

41.42.Section 1065.190 is amended by revising Table 1 to read as follows: 

§1065.190 PM-stabilization and weighing environments for gravimetric analysis. 

* * * * * 

(d) * * * 

Table 1 of §1065.190—Dewpoint tolerance 

as a function of % PM change and % sulfuric acid PM

Expected sulfuric 

acid fraction of PM

±0.5 % PM 

mass change

±1.0 % PM 

mass change

±2.0 % PM 

mass change

5 % ±3.0 °C ±6.0 °C ±12 °C 

50 % ±0.303 °C ±0.606 °C ±1.2 °C

100 % ±0.15 °C ±0.303 °C ±0.606 °C 

* * * * * 

Subpart C—[Amended] 

42.43.Section 1065.205 is amended by revising Table 1 to read as follows: 

§1065.205 Performance specifications for measurement instruments. 

Your test system as a whole must meet all the applicable calibrations, verifications, and 

test-validation criteria specified in subparts D and F of this part or subpart J of this part 

for using PEMS and for performing field testing. We recommend that your instruments 

meet the specifications in Table 1 of this section for all ranges you use for testing. We 

also recommend that you keep any documentation you receive from instrument 

manufacturers showing that your instruments meet the specifications in Table 1 of this 

section. 
Table 1 of §1065.205–Recommended performance specifications for measurement instruments 

Measurement Instrument 

Measured 

quantity 

symbol 

Complete System 

Rise time (t10-90) and 

Fall time (t90-10)a

Recording 

update frequency Accuracyb Repeatabilityb Noiseb

Engine speed transducer fn 1 s 1 Hz means 2.0 % of pt. or 0.5 % of max. 1.0 % of pt. or 0.25 % of max. 0.05 % of max Engine torque transducer T 1 s 1 Hz means 2.0 % of pt. or 1.0 % of max. 1.0 % of pt. or 0.5 % of max 0.05 % of max. Electrical work (active-power meter) W 1 s 1 Hz means 2.0 % of pt. or 0.5 % of max. 1.0 % of pt. or 0.25 % of max. 0.05 % of max General pressure transducer (not a part of another instrument) p 5 s 1 Hz 2.0 % of pt. or 1.0 % of max. 1.0 % of pt. or 0.505 % of max. 0.1 % of max Atmospheric pressure meter used for PM-stabilization and balance environments 

patmos 50 s 5 times per hour 50 Pa 25 Pa 5 Pa 

General purpose atmospheric pressure meter patmos 50 s 5 times per hour 250 Pa 100Pa 50 Pa Temperature sensor for PMstabilization and balance environments 

T 50 s 0.1 Hz 0.25 K 0.1 K 0.1 K 

Other temperature sensor (not a part of another instrument) T 10 s 0.5 Hz 0.4 % of pt. K or 0.2 % of max. K 0.2 % of pt. K or 0.1 % of max. K 0.1 % of max Dewpoint sensor for intake air, PM-stabilization and balance environments 

Tdew 50 s 0.1 Hz 0.25 K 0.1 K 0.02 K 

Other dewpoint sensor Tdew 50 s 0.1 Hz 1 K 0.5 K 0.1 K Fuel flow meterc(Fuel totalizer) m

 5 s 

(N/A) 

1 Hz 

(N/A) 

2.0 % of pt. or 

1.5 % of max. 

1.0 % of pt. or 

0.75 % of max. 0.5 % of max. 

Total diluted exhaust meter (CVS) c(With heat exchanger before meter) n

 1 s 

(5 s) 

1 Hz means 

(1 Hz) 

2.0 % of pt. or 

1.5 % of max. 

1.0 % of pt. or 

0.75 % of max. 1.0 % of max. 

Dilution air, inlet air, exhaust, and sample flow metersc n

 1 s 1 Hz means of 5 Hz samples 2.5 % of pt. or 1.5 % of max. 1.25 % of pt. or 0.75 % of max. 1.0 % of max. 

Continuous gas analyzer x 5 s 1 Hz 2.0 % of pt. or 2.0 % of meas. 1.0 % of pt. or 1.0 % of meas. 1.0 % of max. Batch gas analyzer x N/A N/A 2.0 % of pt. or 2.0 % of meas. 1.0 % of pt. or 1.0 % of meas. 1.0 % of max. Gravimetric PM balance mPM N/A N/A See §1065.790 0.5 μg N/A Inertial PM balance mPM 5 s 1 Hz 2.0 % of pt. or 2.0 % of meas. 1.0 % of pt. or 1.0 % of meas. 0.2 % of max. a The performance specifications identified in the table apply separately for rise time and fall time. b Accuracy, repeatability, and noise are all determined with the same collected data, as described in §1065.305, and based on absolute values. “pt.” refers to the overall flowweighted mean value expected at the standard; “max.” refers to the peak value expected at the standard over any test interval, not the maximum of the instrument’s range; “meas” 

refers to the actual flow-weighted mean measured over any test interval. 

c The procedure for accuracy, repeatability and noise measurement described in §1065.305 may be modified for flow meters to allow noise to be measured at the lowest calibrated 

value instead of zero flow rate.
44. Section 1065.220 is amended by revising paragraph (a) and adding a new paragraph 

(a)(1)(iii) to read as follows: 

§1065.220 Fuel flow meter. 

* * * * * 

(a) Application. You may use fuel flow in combination with a chemical balance of 

carbon (or oxygen) between the fuel, inlet air, and raw exhaust to calculate raw exhaust 

flow as described in §1065.650655(e), as follows: 

(1) * * * 

(i) * * * 

(ii) * * * 

(iii) For calculating the dilution air flow for background correction as described in 

§1065.667. 

* * * * * 

45. Section 1065.225 is amended by revising paragraph (a) and adding new paragraphs 

(a)(1)(iii) and (a)(1)(iv) to read as follows: 

§1065.225 Intake-air flow meter. 

* * * * * 

(a) Application. You may use an intake-air flow meter in combination with a chemical 

balance of carbon (or oxygen) between the fuel, inlet air, and raw exhaust to calculate 

raw exhaust flow as described in §1065.650655(e) and (f), as follows: 

(1) * * * 

(i) * * * 

(ii) * * * 

(iii) For validating minimum dilution ratio for PM batch sampling as described in 

§1065.546. 

(iv) For calculating the dilution air flow for background correction as described in 

§1065.667. 

* * * * * 

46. Section 1065.250 is amended by revising paragraphthe introductory heading and 

paragraphs (a) and (b) to read as follows: 

§1065.250 Nondispersive infra-redinfrared analyzer. 

* * * * *

(a) Application. Use a nondispersive infrared (NDIR) analyzer to measure CO and CO2

concentrations in raw or diluted exhaust for either batch or continuous sampling.

(b) Component requirements. We recommend that you use an NDIR analyzer that meets 

the specifications in Table 1 of §1065.205. Note that your NDIR-based system must 

meet the calibration and verifications in §1065.350 and §1065.355 and it must also meet 

the linearity verification in §1065.307. You may use an NDIR analyzer that has 

compensation algorithms that are functions of other gaseous measurements and the 

engine’s known or assumed fuel properties. The target value for any compensation 

algorithm is 0.0 % (that is, no bias high and no bias low), regardless of the 

uncompensated signal’s bias. 

* * * * * 
47. Section 1065.260 is amended by revising paragraphs (a), (b), (c), and (e) and adding 

paragraph (f) to read as follows: 

§1065.260 Flame-ionization detector. 

* * * * * 

(a) Application. Use a flame-ionization detector (FID) analyzer to measure hydrocarbon 

concentrations in raw or diluted exhaust for either batch or continuous sampling. 

Determine hydrocarbon concentrations on a carbon number basis of one, C1. For 

measuring THC or THCE you must use a FID analyzer. For measuring CH4 you must 

meet the requirements of paragraph (f) of this section.Determine methane and 

nonmethane hydrocarbon values as described in paragraph (e) of this section. See 

subpart I of this part for special provisions that apply to measuring hydrocarbons when 

testing with oxygenated fuels. 

(b) Component requirements. We recommend that you use a FID analyzer that meets the 

specifications in Table 1 of §1065.205. Note that your FID-based system for measuring 

THC, THCE, or CH4 must meet all of the verifications for hydrocarbon measurement in 

subpart D of this part, and it must also meet the linearity verification in §1065.307. You 

may use a FID analyzer that has compensation algorithms that are functions of other 

gaseous measurements and the engine’s known or assumed fuel properties. The target 

value for any compensation algorithm is 0.0 % (that is, no bias high and no bias low), 

regardless of the uncompensated signal’s bias. 

(c) Heated FID analyzers. For measuring THC or THCE from compression-ignition 

engines, two-stroke spark-ignition engines, and four-stroke spark-ignition engines below 

19 kW, you must use heated FID analyzers that maintain all surfaces that are exposed to 

emissions at a temperature of (191 ±11) °C. 

(d) * * * 

(e) NMHC. For demonstrating compliance with NMHC standards, you may either 

measure THC and CH4 and determine NMHC as described in §1065.660(b)(2) or (3)), or 

you may measure THC and determine NMHC as described in §1065.660(b)(1).Methane. 

FID analyzers measure total hydrocarbons (THC).To determine nonmethane 

hydrocarbons (NMHC), quantify methane, CH4, either with a nonmethane cutter and a 

FID analyzer as described in §1065.265, or with a gas chromatograph as described in 

§1065.267. Instead of measuring methane, you may assume that 2 % of measured total 

hydrocarbons is methane, as described in §1065.650(c)(1)(vi). For a FID analyzer used 

to determine NMHC, determine its response factor to CH4, RFCH4, as described in 

§1065.360. Note that NMHC-related calculations are described in §1065.660. 

(f) CH4. For reporting CH4 or for demonstrating compliance towith CH4 standards or 

reporting requirements, you may use a FID analyzer with a nonmethane cutter as 

described in §1065.265 or you may use a GC-FID as described in §1065.267. Determine 

CH4 as described in §1065.660(c). 

48. Section 1065.265 is amended by revising paragraph (b) to read as follows: 

§1065.265 Nonmethane cutter. 

* * * * * 

 (b) System performance. Determine nonmethane-cutter performance as described in 

§1065.365 and use the results to calculate CH4 or NMHC emissions in §1065.660. 
* * * * * 

49. Section 1065.267 is amended by revising paragraphs (a) and (b) to read as follows: 

§1065.267 Gas chromatograph with a flame ionization detector. 

* * * * * 

(a) Application. You may use a gas chromatograph with a flame ionization detector (GCFID)to measure CH4 concentrations of diluted exhaust for batch sampling. While you 

may also use a nonmethane cutter to measure CH4, as described in §1065.265, use a 

reference procedure based on a gas chromatograph for comparison with any proposed 

alternate measurement procedure under §1065.10. 

(b) Component requirements. We recommend that you use a GC-FID gas chromatograph

that meets the specifications in Table 1 of §1065.205, and it must also meet the linearity 

verification in §1065.307. 

50. Section 1065.267 is amended by revising paragraphs (a) and (b) to read as follows: 

§1065.270 Chemiluminescent detector. 

* * * * * 

(b) Component requirements. We recommend that you use a CLD that meets the 

specifications in Table 1 of §1065.205. Note that your CLD-based system must meet the 

quench verification in §1065.370 and it must also meet the linearity verification in 

§1065.307. You may use a heated or unheated CLD, and you may use a CLD that 

operates at atmospheric pressure or under a vacuum. You may use a CLD that has 

compensation algorithms that are functions of other gaseous measurements and the 

engine’s known or assumed fuel properties. The target value for any compensation 

algorithm is 0.0 % (that is, no bias high and no bias low), regardless of the 

uncompensated signal’s bias. 

* * * * * 

51. Section 1065.272 is amended by revising paragraph (b) to read as follows: 

§1065.272 N2O measurement devices. 

* * * * * 

(b) Component requirements. We recommend that you use an NDUV analyzer that 

meets the specifications in Table 1 of §1065.205. Note that your NDUV-based system 

must meet the verifications in §1065.372 and it must also meet the linearity verification 

in §1065.307. You may use a NDUV analyzer that has compensation algorithms that are 

functions of other gaseous measurements and the engine’s known or assumed fuel 

properties. The target value for any compensation algorithm is 0.0 % (that is, no bias high 

and no bias low), regardless of the uncompensated signal’s bias. 

* * * * * 

52. Section 1065.275 is amended by revising paragraphs (b)(1), (b)(2), (b)(3), (b)(4), 

and (c) and adding a new paragraphs (b)(5) and (b)(6) to read as follows: 

§1065.275 N2O measurement devices. 

* * * * * 

(b) * * * 
(1) Nondispersive infra-redinfrared (NDIR) analyzer. You may use an NDIR analyzer 

that has compensation algorithms that are functions of other gaseous measurements and 

the engine’s known or assumed fuel properties. The target value for any compensation 

algorithm is 0.0 % (that is, no bias high and no bias low), regardless of the 

uncompensated signal’s bias. 

(2) Fourier transform infra-redinfrared (FTIR) analyzer. You may use an FTIR analyzer 

that has compensation algorithms that are functions of other gaseous measurements and 

the engine’s known or assumed fuel properties. The target value for any compensation 

algorithm is 0.0 % (that is, no bias high and no bias low), regardless of the 

uncompensated signal’s bias. Use appropriate analytical procedures for interpretation of 

infrared spectra. For example, EPA Test Method 320 is considered a valid method for 

spectral interpretation (see http://www.epa.gov/ttn/emc/methods/method320.html). 

(3) Pulsed-mode high-resolution narrow band mid-IR (PMHRNBIR) analyzer. You may 

use a PMHRNBIR analyzer (commonly known as a Quantum Cascade Laser infrared 

analyzer). You may use a laser infrared analyzer that has compensation algorithms that 

are functions of other gaseous measurements and the engine’s known or assumed fuel 

properties. The target value for any compensation algorithm is 0 % (that is, no bias high 

and no bias low), regardless of the uncompensated signal’s bias.

(4) Modulated continuous wave high-resolution narrow band mid-IR (MCWHRNBIR) 

analyzer. You may use a MCWHRNBIR analyzer (commonly known as a Quantum 

Cascade Laser Infrared analyzer) that has compensation algorithms that are functions of 

other gaseous measurements and the engine’s known or assumed fuel properties. The 

target value for any compensation algorithm is 0 % (that is, no bias high and no bias 

low), regardless of the uncompensated signal’s bias. Examples of laser infrared analyzers 

are pulsed-mode high-resolution narrow band mid-infrared analyzers, and modulated 

continuous wave high-resolution narrow band mid-infrared analyzers.

(354) Photoacoustic analyzer. You may use a photoacoustic analyzer that has 

compensation algorithms that are functions of other gaseous measurements. The target 

value for any compensation algorithm is 0.0 % (that is, no bias high and no bias low), 

regardless of the uncompensated signal’s bias. Use an optical wheel configuration that 

gives analytical priority to measurement of the least stable components in the sample. 

Select a sample integration time of at least 5 seconds. Take into account sample chamber 

and sample line volumes when determining flush times for your instrument. 

(465) Gas chromatograph analyzer. You may use a gas chromatograph with an electroncapture detector (GC-ECD) to measure N2O concentrations of diluted exhaust for batch 

sampling. 

(i)You may use a packed or porous layer open tubular (PLOT) column phase of suitable 

polarity and length to achieve adequate resolution of the N2O peak for analysis. 

Examples of acceptable columns are a PLOT column consisting of bonded polystyrenedivinylbenzene or a Porapack Q packed column. Take the column temperature profile 

and carrier gas selection into consideration when setting up your method to achieve 

adequate N2O peak resolution. 

(ii) Use good engineering judgment to zero your instrument and correct for drift. You do 

not need to follow the specific procedures in §1065.530 and §1065.550(b) that would 

otherwise apply. For example, you may perform a span gas measurement before and 

after sample analysis without zeroing. U and use the average area counts of the pre-span 
and post-span measurements to generate a response factor (area counts/span gas 

concentration), which you then multiply by the area counts from your sample to generate 

the sample concentration. 

(c) Interference verificationvalidation. Perform interference verification validation for 

NDIR, FTIR, PMHRNBIR, MCWHRNBIRlaser infrared analyzers, and photoacoustic 

analyzers using the procedures of §1065.375. Interference verification validation is not 

required for GC-ECD. Certain interference gases can positively interfere with NDIR, 

FTIR, and photoacoustic analyzers by causing a response similar to N2O. When running 

the interference verification for these analyzers, use interference gases as follows: 

(1) The interference gases for NDIR analyzers are CO, CO2, H2O, CH4, and SO2. Note 

that interference species, with the exception of H2O, are dependent on the N2O infrared 

absorption band chosen by the instrument manufacturer and should be determined 

independently for each analyzer. For each analyzer determine the N2O infrared 

absorption band. For each N2O infrared absorption band, use good engineering judgment 

to determine which interference gases to use in the verification. 

(2) Use good engineering judgment to determine interference gases for FTIR, 

PMHRNBIR, and MCWHRNBIRlaser infrared analyzers. Note that interference species, 

with the exception of H2O, are dependent on the N2O infrared absorption band chosen by 

the instrument manufacturer and should be determined dently for each analyzer.. For 

each analyzer determine the N2O infrared absorption band. For each N2O infrared 

absorption band, use good engineering judgment to determine interference gases to use in 

the verification. 

(3) The interference gases for photoacoustic analyzers are CO, CO2, and H2O. 

 * * * * * 

53. Section 1065.280 is amended by revising paragraph (b) to read as follows: 

§1065.280 Paramagnetic and magnetopneumatic O2 detection analyzers. 

* * * * * 

(b) Component requirements. We recommend that you use a PMD or MPD analyzer that 

meets the specifications in Table 1 of §1065.205. Note that it must meet the linearity 

verification in §1065.307. You may use a PMD or MPD that has compensation 

algorithms that are functions of other gaseous measurements and the engine’s known or 

assumed fuel properties. The target value for any compensation algorithm is 0.0 % (that 

is, no bias high and no bias low), regardless of the uncompensated signal’s bias. 

* * * * * 

54. Section 1065.284 is amended by revising paragraph (b) to read as follows: 

§1065.284 Zirconia (ZrO2) analyzer. 

* * * * * 

(b) Component requirements. We recommend that you use a ZrO2 analyzer that meets 

the specifications in Table 1 of §1065.205. Note that your ZrO2-based system must meet 

the linearity verification in §1065.307. You may use a Zirconia analyzer that has 

compensation algorithms that are functions of other gaseous measurements and the 

engine’s known or assumed fuel properties. The target value for any compensation 

algorithm is 0.0 % (that is, no bias high and no bias low), regardless of the 

uncompensated signal’s bias. 
* * * * *

26.

* * * * *

55. Section 1065.290 is amended by revising paragraph (b) to read as follows: 

§1065.295 PM inertial balance for field-testing analysis. 

* * * * * 

(b) Component requirements. We recommend that you use a balance that meets the 

specifications in Table 1 of §1065.205. Note that your balance-based system must meet 

the linearity verification in §1065.307. If the balance uses an internal calibration process 

for routine spanning and linearity verifications, the process must be NIST-traceable. You 

may use an inertial PM balance that has compensation algorithms that are functions of 

other gaseous measurements and the engine’s known or assumed fuel properties. The 

target value for any compensation algorithm is 0.0 % (that is, no bias high and no bias 

low), regardless of the uncompensated signal’s bias. 

* * * * * 

Subpart D—[Amended] 

56. Section 1065.303 is amended by revising Table 1 of 1065.303 to read as follows: 

§1065.303 Summary of required calibration and verifications. 

The following table summarizes the required and recommended calibrations and 

verifications described in this subpart and indicates when these have to be performed: 

Table 1 of §1065.303–Summary of required calibration and verifications. 

Type of calibration or verification Minimum frequencya

§1065.305: Accuracy, repeatability and noise 

Accuracy: Not required, but recommended for initial installation. 

Repeatability: Not required, but recommended for initial installation. 

Noise: Not required, but recommended for initial installation. 

§1065.307: Linearity verification 

Speed: Upon initial installation, within 370 days before testing and 

after major maintenance. 

Torque: Upon initial installation, within 370 days before testing and 

after major maintenance. 

Electrical power: Upon initial installation, within 370 days before 

testing and after major maintenance. 

Fuel flow rate: Upon initial installation, within 370 days before 

testing, and after major maintenance. 

Intake-air, dilution air, diluted exhaust, and batch samplerClean gas 

and diluted exhaust sampler flow rates: Upon initial installation, 

within 370 days before testing and after major maintenance, unless 

flow is verified by propane check or by carbon or oxygen balance. 

Raw exhaust flow rate: Upon initial installation, within 185 days 

before testing and after major maintenance, unless flow is verified by 

propane check or by carbon or oxygen balance. 

Gas dividers: Upon initial installation, within 370 days before testing, 

and after major maintenance. 

Gas analyzers (unless otherwise noted): Upon initial installation, 

within 35 days before testing and after major maintenance.

FTIR and photoacoustic analyzers: Upon initial installation, within 

370 days before testing and after major maintenance. 

GC-ECD: Upon initial installation and after major maintenance. 

PM balance: Upon initial installation, within 370 days before testing 

and after major maintenance. 

Pressure, temperature, and dewpoint: Upon initial installation, within 
370 days before testing and after major maintenance.

§1065.308: Continuous gas analyzer system 

response and updating-recording 

verification—for gas analyzers not 

continuously compensated for other gas 

species 

Upon initial installation or after system modification that would affect 

response. 

§1065.309: Continuous gas analyzer systemresponse and updating-recording 

verification—for gas analyzers continuously 

compensated for other gas species

Upon initial installation or after system modification that would affect 

response. 

§1065.310: Torque Upon initial installation and after major maintenance. 

§1065.315: Pressure, temperature, dewpoint Upon initial installation and after major maintenance. 

§1065.320: Fuel flow Upon initial installation and after major maintenance.

§1065.325: Intake flow Upon initial installation and after major maintenance. 

§1065.330: Exhaust flow Upon initial installation and after major maintenance. 

§1065.340: Diluted exhaust flow (CVS) Upon initial installation and after major maintenance. 

§1065.341: CVS and batch sampler 

verificationb 

Upon initial installation, within 35 days before testing, and after 

major maintenance.

§1065.342 Sample dryer verification 

For thermal chillers: upon installation and after major maintenance. 

For osmotic membranes; upon installation, within 35 days of testing, 

and after major maintenance. 

§1065.345: Vacuum leak 

For laboratory testing: upon initial installation of the sampling 

system, within 8 hours before the start of the first test interval of each 

duty-cycle sequence, and after maintenance such as pre-filter 

changes. 

For field testing: after each installation of the sampling system on the 

vehicle, prior to the start of the field test, and after maintenance such 

as pre-filter changes. 

§1065.350: CO2 NDIR H2O interference Upon initial installation and after major maintenance. 

§1065.355: CO NDIR CO2 and H2O 

interference Upon initial installation and after major maintenance. 

§1065.360: FID calibration 

THC FID optimization, and THC FID 

verification. 

Calibrate all FID analyzers: upon initial installation and after major 

maintenance. 

Optimize and determine CH4 response for THC FID analyzers: 

upon initial installation and after major maintenance. 

Verify CH4

 response for THC FID analyzers: upon initial installation,

within 185 days before testing, and after major maintenance. 

§1065.362: Raw exhaust FID O2 interference 

For all FID analyzers: upon initial installation, and after major 

maintenance. 

For THC FID analyzers: upon initial installation, after major 

maintenance, and after FID optimization according to §1065.360. 

§1065.365: Nonmethane cutter penetration Upon initial installation, within 185 days before testing, and after 

major maintenance. 

§1065.370: CLD CO2 and H2O quench Upon initial installation and after major maintenance. 

§1065.372: NDUV HC and H2O interference Upon initial installation and after major maintenance.

§1065.375: N2O analyzer interference Upon initial installation and after major maintenance. 

§1065.376: Chiller NO2 penetration Upon initial installation and after major maintenance. 

§1065.378: NO2-to-NO converter conversion Upon initial installation, within 35 days before testing, and after 

major maintenance. 

§1065.390: PM balance and weighing 

Independent verification: upon initial installation, within 370 days 

before testing, and after major maintenance. 

Zero, span, and reference sample verifications: within 12 hours of 

weighing, and after major maintenance. 

§1065.395: Inertial PM balance and weighing 

Independent verification: upon initial installation, within 370 days 

before testing, and after major maintenance. 

Other verifications: upon initial installation and after major 

maintenance.

a

Perform calibrations and verifications more frequently, according to measurement system manufacturer instructions 

and good engineering judgment. 

bThe CVS verification described in §1065.341 is not required for systems that agree within ±2 % based on a chemical 

balance of carbon or oxygen of the intake air, fuel, and diluted exhaust. 
* * * * *

27.

* * * * *

57. Section 1065.307 is amended by revising paragraph (a) and Table 1 of 1065.307 to 

read as follows: 

§1065.307 Linearity verification. 

(a) Scope and frequency. Perform a linearity verification on each measurement system 

listed in Table 1 of this section at least as frequently as indicated in Table 1 of 

§1065.303the table303, consistent with measurement system manufacturer 

recommendations and good engineering judgment. Note that this linearity verification 

may replace requirements we previously referred to as “calibrations”. The intent of a 

linearity verification is to determine that a measurement system responds proportionally 

over the measurement range of interest. A linearity verification generally consists of 

introducing a series of at least 10 reference values to a measurement system. The 

measurement system quantifies each reference value. The measured values are then 

collectively compared to the reference values by using a least squares linear regression 

and the linearity criteria specified in Table 1 of this section. 

(b) * * * 
Table 1 of §1065.307–Measurement systems that require linearity verifications. 

Measurement 

system Quantity Linearity criteria 

|| xmin(a1-1)+a0 | a1 SEE r

2

Speed fn

≤ 0.05 % · nmax f 0.98-1.02 ≤ 2 % · nmax f ≥ 0.990 

Torque T ≤ 1 % · Tmax 0.98-1.02 ≤ 2 % · Tmax ≥ 0.990 

Electrical power P ≤ 1 % · Pmax 0.98-1.02 ≤ 2 % · Pmax ≥ 0.990 

Fuel flow rate m ≤ 1 % · mmax  0.98-1.02 ≤ 2 % · mmax  ≥ 0.990 

Intake-air 

flow rate n ≤ 1 % · max n 0.98-1.02 ≤ 2 % · max n ≥ 0.990 

Dilution air 

flow rate n ≤ 1 % · max n 0.98-1.02 ≤ 2 % · max n ≥ 0.990 

Diluted exhaust 

flow rate n ≤ 1 % · nmax  0.98-1.02 ≤ 2 % · nmax  ≥ 0.990 

Raw exhaust 

flow rate n ≤ 1 % · nmax  0.98-1.02 ≤ 2 % · nmax  ≥ 0.990 

Batch sampler 

flow rates n ≤ 1 % · nmax  0.98-1.02 ≤ 2 % · nmax  ≥ 0.990 

Gas dividers x/xspan ≤ 0.5 % · xmax/xspan 0.98-1.02 ≤ 2 % · xmax/xspan ≥ 0.990 

Gas analyzers for 

laboratory testing x ≤ 0.5 % · max x 0.99-1.01 ≤ 1 % · max x ≥ 0.998 

Gas analyzers for 

field testing x ≤ 1 % · max x 0.99-1.01 ≤ 1 % · max x ≥ 0.998 

PM balance m ≤ 1 % · mmax 0.99-1.01 ≤ 1 % · mmax ≥ 0.998 

Pressures p ≤ 1 % · max p 0.99-1.01 ≤ 1 % · max p ≥ 0.998 

Dewpoint for 

intake air, PMstabilization and 

balance 

environments 

Tdew ≤ 0.5 % · Tdewmax 0.99-1.01 ≤ 0.5 % · Tdewmax ≥ 0.998 

Other dewpoint 

measurements Tdew ≤ 1 % · Tdewmax 0.99-1.01 ≤ 1 % · Tdewmax ≥ 0.998 

Analog-to-digital 

conversion of 

temperature 

signals 

T ≤ 1 % · Tmax 0.99-1.01 ≤ 1 % · Tmax ≥ 0.998 

58. Section 1065.340 is amended by revising paragraphs (b), (c), (d), (e), (f), (g) and (h) 

and adding paragraph (i) to read as follows:

§1065.340 Diluted exhaust flow (CVS) calibration. 

* * * * * 

(b) Scope and frequency. Perform this calibration while the flow meter is installed in its 

permanent position, except as allowed in paragraph (c) of this section. Perform this 

calibration after you change any part of the flow configuration upstream or downstream 

of the flow meter that may affect the flow-meter calibration. Perform this calibration 

upon initial CVS installation and whenever corrective action does not resolve a failure to 

meet the diluted exhaust flow verification (i.e., propane check) in §1065.341. 

(c) Ex-situ CFV and SSV calibration. You may remove a CFV or SSV from its 

permanent position for calibration provided thatas long as it meets the following 

requirements when installed in the CVS: 

(1) Upon installation of the CFV(s) or SSV into the CVS, use good engineering judgment

to verify that you have not introduced any leaks between the CVS inlet and the venturi. 
(2) After ex-situ venturi calibration, you must verify all venturi flow combinations for 

CFVs or at minimum of 10 flow points for an SSV using the propane check as described 

in §1065.341. Your propane check result for each venturi flow point may not exceed the 

tolerance in §1065.341(f)(5). 

(3) To validateverify your ex-situ calibration for a CVS with more than a single CFV, 

perform the following check to verify that there are no flow meter entrance effects that 

can contribute adversely to the CVS flow determination. This does not apply for a CVS 

that contains only a single CFVprevent you from passing this verification. 

(i) Use a constant flow device like a CFO kit to deliver a constant flow of propane to the 

dilution tunnel. 

(ii) Measure hydrocarbon concentrations at a minimum of 10 flowsseparate flow rates for 

an SSV flow meter, or at all possible flow combinations for a CFV flow meter, while 

keeping the flow of propane constant. We recommend thatselecting CVS flows be 

selectedflow rates in a random order. 

(iii) Measure the concentration of dilution air hydrocarbon background in the dilution air 

at the start ofbeginning and upon completionend of this test. Subtract the average 

background concentration from each concentration measurement at each flow point 

before performing the regression analysis in paragraph (c)(3)(iv) of this section. 

(iv) Perform a power regression ofusing all the paired values of flow pointsrate and 

corrected concentration data pairs to obtain a relationship in the form of y = a · x

m

x

b

. Use 

concentration as the independent variable and flow rate as the dependent variable. 

Calculate the residual of For each flow data point with respect to the power regression 

best, calculate the difference between the measured flow rate and the value represented 

by the curve fit line. All residuals. The difference at each point must be less than ±1 % of 

the corresponding observed flowappropriate regression value. The value of mb must be 

within the range ofbetween –1.005 toand –0.995. 

(v) If your results do not meet these limits set in paragraph (iv) of this section, take 

corrective action to determine if venturi entrance effects caused by the piping 

configuration upstream of the venturi are the reason for the discrepancy. Other possible 

sources of error are described in consistent with §1065.341(a). 

(dcd) Reference flow meter. Calibrate a CVS flow meter using a reference flow meter 

such as a subsonic venturi flow meter, a long-radius ASME/NIST flow nozzle, a smooth 

approach orifice, a laminar flow element, a set of critical flow venturis, or an ultrasonic 

flow meter. Use a reference flow meter that reports quantities that are NIST-traceable 

within ±1 % uncertainty. Use this reference flow meter’s response to flow as the 

reference value for CVS flow-meter calibration. 

(ede) Configuration. Do not use an upstream screen or other restriction that could affect 

the flow ahead of the reference flow meter, unless the flow meter has been calibrated 

with such a restriction. 

(fef) PDP calibration. Calibrate a positive-displacement pump (PDP) to determine a 

flow-versus-PDP speed equation that accounts for flow leakage across sealing surfaces in 

the PDP as a function of PDP inlet pressure. Determine unique equation coefficients for 

each speed at which you operate the PDP. Calibrate a PDP flow meter as follows: 

(1) Connect the system as shown in Figure 1 of this section. 
(2) Leaks between the calibration flow meter and the PDP must be less than 0.3 % of the 

total flow at the lowest calibrated flow point; for example, at the highest restriction and 

lowest PDP-speed point. 

(3) While the PDP operates, maintain a constant temperature at the PDP inlet within ±2 

% of the mean absolute inlet temperature, Tin . 

(4) Set the PDP speed to the first speed point at which you intend to calibrate. 

(5) Set the variable restrictor to its wide-open position. 

(6) Operate the PDP for at least 3 min to stabilize the system. Continue operating the 

PDP and record the mean values of at least 30 seconds of sampled data of each of the 

following quantities: 

(i) The mean flow rate of the reference flow meter, ref n . This may include several 

measurements of different quantities, such as reference meter pressures and temperatures, 

for calculating ref n . 

(ii) The mean temperature at the PDP inlet, Tin . 

(iii) The mean static absolute pressure at the PDP inlet, in p . 

(iv) The mean static absolute pressure at the PDP outlet, out p . 

(v) The mean PDP speed, nPDP f . 

(7) Incrementally close the restrictor valve to decrease the absolute pressure at the inlet to 

the PDP, in p . 

(8) Repeat the steps in paragraphs (e)(6) and (7) of this section to record data at a 

minimum of six restrictor positions ranging from the wide open restrictor position to the 

minimum expected pressure at the PDP inlet. 

(9) Calibrate the PDP by using the collected data and the equations in §1065.640. 

(10) Repeat the steps in paragraphs (e)(6) through (9) of this section for each speed at 

which you operate the PDP. 

(11) Use the equations in §1065.642 to determine the PDP flow equation for emission 

testing. 

(12) Verify the calibration by performing a CVS verification (i.e., propane check) as 

described in §1065.341. 

(13) Do not use the PDP below the lowest inlet pressure tested during calibration. 

(gfg) CFV calibration. Calibrate a critical-flow venturi (CFV) to verify its discharge 

coefficient, Cd, at the lowest expected static differential pressure between the CFV inlet 

and outlet. Calibrate a CFV flow meter as follows:

(1) Connect the system as shown in Figure 1 of this section. 

(2) Verify that any leaks between the calibration flow meter and the CFV are less than 

0.3 % of the total flow at the highest restriction.

(233) Start the blower downstream of the CFV. 

(344) While the CFV operates, maintain a constant temperature at the CFV inlet within 

±2 % of the mean absolute inlet temperature, Tin .(4) Leaks between the calibration flow 

meter and the CFV must be less than 0.3 % of the total flow at the highest restriction..

(5) Set the variable restrictor to its wide-open position. Instead of a variable restrictor, 

you may alternately vary the pressure downstream of the CFV by varying blower speed 
or by introducing a controlled leak. Note that some blowers have limitations on 

nonloaded conditions. 

(6) Operate the CFV for at least 3 min to stabilize the system. Continue operating the 

CFV and record the mean values of at least 30 seconds of sampled data of each of the 

following quantities: 

(i) The mean flow rate of the reference flow meter, ref n . This may include several 

measurements of different quantities, such as reference meter pressures and temperatures, 

for calculating ref n . 

(ii) The mean dewpoint of the calibration air, Tdew . See §1065.640 for permissible 

assumptions during emission measurements. 

(iii) The mean temperature at the venturi inlet, Tin . 

(iv) The mean static absolute pressure at the venturi inlet, in p .

(v) The mean static differential pressure between the CFV inlet and the CFV outlet, 

CFV ∆p . 

(7) Incrementally close the restrictor valve or decrease the downstream pressure to 

decrease the differential pressure across the CFV, CFV ∆p . 

(8) Repeat the steps in paragraphs (f)(6) and (7) of this section to record mean data at a 

minimum of ten restrictor positions, such that you test the fullest practical range of CFV ∆p

expected during testing. We do not require that you remove calibration components or 

CVS components to calibrate at the lowest possible restrictions. 

(9) Determine Cd and the lowest allowable pressure ratio, r, according to §1065.640. 

(10) Use Cd to determine CFV flow during an emission test. Do not use the CFV below 

the lowest allowed r, as determined in §1065.640. 

(11) Verify the calibration by performing a CVS verification (i.e., propane check) as 

described in §1065.341. 

(12) If your CVS is configured to operate more than one CFV at a time in parallel, 

calibrate your CVS by one of the following: 

(i) Calibrate every combination of CFVs according to this section and §1065.640. Refer 

to §1065.642 for instructions on calculating flow rates for this option. 

(ii) Calibrate each CFV according to this section and §1065.640. Refer to §1065.642 for 

instructions on calculating flow rates for this option. 

(ghh) SSV calibration. Calibrate a subsonic venturi (SSV) to determine its calibration 

coefficient, Cd, for the expected range of inlet pressures. Calibrate an SSV flow meter as 

follows: 

(1) Connect the system as shown in Figure 1 of this section. 

(2) Verify that any leaks between the calibration flow meter and the SSV are less than 0.3 

% of the total flow at the highest restriction. 

(233) Start the blower downstream of the SSV.(3) Leaks between the calibration flow 

meter and the SSV must be less than 0.3 % of the total flow at the highest restriction. 

(4) While the SSV operates, maintain a constant temperature at the SSV inlet within ±2 

% of the mean absolute inlet temperature, Tin . 

(5) Set the variable restrictor or variable-speed blower to a flow rate greater than the 

greatest flow rate expected during testing. You may not extrapolate flow rates beyond 
calibrated values, so we recommend that you make sure the Reynolds number, Re#

, at the 

SSV throat at the greatest calibrated flow rate is greater than the maximum Re# expected 

during testing. 

(6) Operate the SSV for at least 3 min to stabilize the system. Continue operating the 

SSV and record the mean of at least 30 seconds of sampled data of each of the following 

quantities: 

(i) The mean flow rate of the reference flow meter ref n . This may include several 

measurements of different quantities, such as reference meter pressures and temperatures, 

for calculating ref n . 

(ii) Optionally, the mean dewpoint of the calibration air, Tdew . See §1065.640 for 

permissible assumptions. 

(iii) The mean temperature at the venturi inlet, Tin . 

(iv) The mean static absolute pressure at the venturi inlet, in p . 

(v) Static differential pressure between the static pressure at the venturi inlet and the 

static pressure at the venturi throat, SSV ∆p . 

(7) Incrementally close the restrictor valve or decrease the blower speed to decrease the 

flow rate. 

(8) Repeat the steps in paragraphs (g)(6) and (7) of this section to record data at a 

minimum of ten flow rates. 

(9) Determine a functional form of Cd versus Re#by using the collected data and the 

equations in §1065.640. 

(10) Verify the calibration by performing a CVS verification (i.e., propane check) as 

described in §1065.341 using the new Cd versus Re#equation. 

(11) Use the SSV only between the minimum and maximum calibrated flow rates. 

(12) Use the equations in §1065.642 to determine SSV flow during a test. 

(hii) Ultrasonic flow meter calibration. [Reserved] 

* * * * * 

59. Section 1065.341 is amended by revising paragraphs (a)(5)), (a)(6), and (f)(5) and 

adding paragraph (a)(7) to read as follows: 

§1065.341 CVS and batch sampler verification (propane check). 

* * * * * 

(a) * * * 

(5) Change in CVS calibration. Perform an in-situa calibration of the CVS flow meter as 

described in §1065.340. 

(6) Flow meter entrance effects. Inspect the CVS tunnel to determine whether the 

entrance effects from the piping configuration upstream of the flow meter adversely 

affect the flow measurement.

(7) Other problems with the CVS or sampling verification hardware or software. Inspect 

the CVS system, CVS verification hardware, and software for discrepancies.

* * * * * 

(f) * * * 
(5) Subtract the reference C3H8 mass from the calculated mass. If this difference is 

within ±2.0 % of the reference mass, the CVS passes this verification. If not, take 

corrective action as described in paragraph (a) of this section. 

* * * * * 

60. Section 1065.350 is amended by revising paragraph (d)(7) to read as follows: 

§1065.350 H2O interference verification for CO2 NDIR analyzers. 

* * * * * 

(d) * * * 

(7) While the analyzer measures the sample’s concentration, record 30 seconds of 

sampled data. Calculate the arithmetic mean of this data. The analyzer meets the 

interference verification if this value is within (0.0 ±0.4) mmol/mol. 

* * * * * 

61. Section 1065.360 is amended by revising paragraph (e) to read as follows: 

§1065.360 FID optimization and verification. 

* * * * * 

(e) THC FID methane (CH4) response verification. This procedure is only for FID 

analyzers that measure THC. If the value of RFCH4[THC-FID] from paragraph (d) of this 

section is within ±5.0 % of its most recent previously determined value, the THC FID 

passes the methane response verification. For example, if the most recent previous value 

for RFCH4[THC-FID] was 1.05 and it changed by ±0.05 to become 1.10 or it changed by -

0.05 to become 1.00, either case would be acceptable because ±4.8 % is less than ±5.0 %. 

Verify RFCH4[THC-FID] as follows: 

* * * * * 

62. Section 1065.370 is amended by revising paragraph (g)(1) to read as follows: 

§1065.370 CLD CO2 and H2O quench verification. 

* * * * * 

(g) * * * 

(1) You may omit this verification if you can show by engineering analysis that for your 

NOx sampling system and your emission calculation procedures, the combined CO2 and 

H2O interference for your NOx CLD analyzer always affects your brake-specific NOx

emission results within no more than ±1.0 % of the applicable NOx standard. If you 

certify to a combined emission standard (such as a NOx + NMHC standard), scale your 

NOx results to the combined standard based on the measured results (after incorporating 

deterioration factors, if applicable). For example, if your final NOx + NMHC value is 

half of the emission standard, double the NOx result to estimate the level of NOx

emissions corresponding to the applicable standard.

* * * * * 

63. Section 1065.372 is amended by revising paragraph (e)(1) to read as follows: 

§1065.372 NDUV analyzer HC and H2O interference verification. 

* * * * * 

(e) * * * 
(1) You may omit this verification if you can show by engineering analysis that for your 

NOx sampling system and your emission calculation procedures, the combined HC and 

H2O interference for your NOx NDUV analyzer always affects your brake-specific NOx

emission results by less than 0.5 % of the applicable NOx standard. 

* * * * * 

64. Section 1065.378 is amended by revising paragraph (d)(3)(iv) to read as follows: 

§1065.378 NO2-to-NO converter conversion verification. 

* * * * * 

(d) * * * 

(3) * * * 

(iv) Switch the ozonator on and adjust the ozone generation rate so the NO measured by 

the analyzer is 20 percent of xNOref or a value which would simulate the maximum 

concentration of NO2 expected during testing, while maintaining at least 10 percent 

unreacted NO. This ensures that the ozonator is generating NO2 at the maximum 

concentration expected during testing. Record the concentration of NO by calculating the 

mean of 30 seconds of sampled data from the analyzer and record this value as xNOmeas.

* * * * * 

Subpart F—[Amended] 

65. Section 1065.510 is amended by revising paragraphs (a) introductory text, (b)(5)(i), 

(b)(6), (c)(2), (c)(4), (d)(5), (f)(3)(i)), (f)(5), and (f)(5g) and adding paragraphs

(b)(7) and ), (f()(3)(iii), and (h) to read as follows: 

§1065.510 Engine mapping. 

(a) Applicability, scope, and frequency. An engine map is a data set that consists of a 

series of paired data points that represent the maximum brake torque versus engine speed, 

measured at the engine's primary output shaft. Map your engine if the standard-setting 

part requires engine mapping to generate a duty cycle for your engine configuration. Map 

your engine while it is connected to a dynamometer or other device that can absorb work 

output from the engine's primary output shaft according to §1065.110. To establish speed 

and torque values for mapping, we generally recommend that you stabilize an engine for 

at least 15 seconds at each setpoint and record the mean feedback speed and torque of the 

last (4 to 6) seconds. Configure any auxiliary work inputs and outputs such as hybrid, 

turbo-compounding, or thermoelectric systems to represent their in-use configurations, 

and use the same configuration for emission testing. See Figure 1 of §1065.210. This may 

involve configuring initial states of charge and rates and times of auxiliary-work inputs 

and outputs. We recommend that you contact the Designated Compliance Officer before 

testing to determine how you should configure any auxiliary-work inputs and outputs. 

Use the most recent engine map to transform a normalized duty cycle from the standardsetting part to a reference duty cycle specific to your engine. Normalized duty cycles are 

specified in the standard-setting part. You may update an engine map at any time by 

repeating the engine-mapping procedure. You must map or re-map an engine before a test 

if any of the following apply:

* * * * * 

(b) * * * 
(6) For engines with a high speed governor, determine warm high-idle speed by one of 

the following methods. You may skip the determination of high-idle speed in this 

paragraph (b)(6) for engines subject to reference duty cycles where all the specified 

normalized reference speeds are 100 % or less and for engines where you are generating 

a transient test cycle as specified in 40 CFR parts 86 and 1048.5) * * *

(i) Use a manufacturer declared warm high-idle speed. You may only use this option (i) 

For any engine subject only to steady-state duty cycles, you may perform an engine map 

by using discrete speeds. Select at least 20 evenly spaced setpoints from 95% of warm 

idle speed to the highest speed above maximum power at which 50% of maximum power 

occurs. We refer to this 50% speed as the check point speed as described in paragraph 

(b)(5)(iii) of this section. At each setpoint, stabilize speed and allow torque to stabilize. 

Record the mean speed and torque at each setpoint. Use linear interpolation to determine 

intermediate speeds and torques. Use this series of speeds and torques to generate the 

power map as described in paragraph (e) of this section.

* * * * *

(6) Use one of the following methods to determine warm high-idle speed for engines with 

a high-speed governor if they are subject to transient testing with a duty cycle that 

includes reference speed values above 100 %:

(i) You may use a manufacturer-declared warm high-idle speed if the engine is 

electronically governed. For engines designed with an electronica high-speed governor 

that shuts off torque output at a manufacturer-specified speed and reactivates at anothera

lower manufacturer-specified speed (e.g.such as engines usingthat use ignition cut-off), 

take the manufacturer declared warm high-idle speed as for governing), declare the 

middle of thisthe specified speed range as the warm high-idle speed. 

(ii) Measure the warm high-idle speed using the following procedure.:

(A) Set operator demand to maximum and use the dynamometer to target azero torque of 

zero on the engine’s primary output shaft. We recommend that you allow the engine to 

stabilize for at least 15 seconds and record the mean feedback speed and torque of the last 

(4 to 6) seconds. If the mean feedback torque is within ±1 % of Tmax mapped, you may use 

this mean feedback speed as the measured warm high-idle speed and you may skip the 

step in paragraph (b)(6)(ii)(B) of this section. If the engine is unstable you must use this 

the observed mean feedback speed at that point as the measured warm high-idle speed.

(B) If the engine is unstable as a result of in-use production components (such as engines 

that use ignition cut-off for governing, as opposed to unstable dynamometer operation), 

you must use the mean feedback speed from paragraph (b)(6)(ii)(A) of this section as the 

measured warm high-idle speed and you may skip the step in paragraph (b)(6)(ii)(B) of 

this section. The unstable engine operation must be due to in-use production components 

(e.g. an ignition cut-off high-speed governor system) and not an engine is considered 

unstable dynamometer torque control loop. The engine is deemed unstable whenif any of 

the 1 Hz mean speed feedback values exceedare not within ±2 % of the calculated mean 

feedback speed as specified in this paragraph. For engines that are unstable,. We 

recommend that you recorddetermine the mean as the value representing the midpoint 

between the observed maximum and minimum recorded feedback speed and torque over 

a positive integer number of oscillations. You may also take the average of the minimum 

and maximum 1 Hz mean speed feedback values observed over at least one full 

oscillation as the mean feedback speed.. 
(BC) If you use ayour dynamometer that is not capable of achieving a mean feedback 

torque within ±1 % of Tmax mapped (e.g. an absorbing-only dynamometer), you must,

operate the engine at a second point with operator demand set to maximum andwith the 

dynamometer set to target a torque that is equal to the recorded mean feedback torque on 

the previous point plus 20 % of Tmax mapped. We recommend that you allow the engine to 

stabilize for at least 15 seconds and record the mean feedback speed and torque of the last 

(4 to 6) seconds. Use these two data points Use this data point and the data point from 

paragraph (b)(6)(ii)(A) of this section to extrapolate the engine speed where torque is 

equal to zero. 

(CD) You may use a manufacturer-declared Tmax instead of the measured Tmax mapped. If 

you have a manufacturer declared Tmaxdo this, or if you are able to determine mean 

feedback speed as described in paragraphs (b)(6)(ii)(A) and (B) of this section, you may 

measure the warm high-idle speed prior tobefore running the speed sweep specified in 

paragraph (b)(5) of this section. You may also measure the warm high-idle speed prior 

to running the speed sweep in paragraph (b)(5) if you can meet the requirements in 

paragraph (b)(6)(ii)(A) of this section.

(677) For engines with a low-speed governor, if a nonzero idle torque is representative of 

in-use operation, operate the engine at warm idle with the manufacturer-declared idle 

torque. Set the operator demand to minimum, use the dynamometer to target the declared 

idle torque, and allow the engine to govern the speed. Measure this speed and use it as 

the warm idle speed for cycle generation in §1065.512. We recommend recording at 

least 30 values of speed and using the mean of those values. If you identify multiple 

warm idle torques under paragraph (f)(4)(i) of this section, measure the warm idle speed 

at each torque. You may map the idle governor at multiple load levels and use this map 

to determine the measured warm idle speed at the declared idle torque(s). 

(c) * * * 

(2) Map the amount of negative torque required to motor the engine by repeating 

paragraph (b) of this section with minimum operator demand. You may start the negative 

torque map at either the minimum or maximum speed infrom paragraph (b) of this 

section. 

* * * * *

(4) For engines with an electric hybrid system, you may create a negative torque map that 

would include the full negative torque of the electric hybrid system, so operator demand 

will be at a minimum when the reference duty cycle specifies negative torque values. 

(d) * * * 

(5) Perform one of the following: 

(i) For any constant-speed engines subject only to steady-state duty cycles (i.e. discretemode or ramped-modal),testing, you may perform an engine map by using a series of

discrete torques. Select at least (5)five evenly spaced torque setpoints from no-load to 80 

% of the manufacturer-declared test torque or to a torque derived from manufactureryour

published maximum power level if the declared test torque is not knownunavailable. 

Starting at the 80 % torque point, select setpoints in 2.5 % intervals, stopping at the 

endpoint torque as defined below. You may map your engine to higher torques. At each 

setpoint, stabilize torque and allow speed to stabilize. Record the mean feedback speed 

and torque at each setpoint. We recommend that you stabilize an engine for at least 15 

seconds at each setpoint and record the mean feedback speed and torque for the last (4 to 
6) seconds. From this series of mean feedback speed and torque values, use linear 

interpolation to determine intermediate values. Use this series of mean feedback speeds 

and torques to generate the power map as described in paragraph (e) of this section. The 

end point torque is defined as the first torque. The endpoint torque is defined as the first 

discrete mapped torque value greater than the torque at maximum observed power where 

the engine outputs 90 % of the maximum observed power; or the torque when engine 

stall has been determined using good engineering judgment (i.e. sudden deceleration of 

engine speed while adding torque).

(ii) For any constant-speed engine, you may perform an engine map by using a 

continuous sweep of torque by continuing to Record record at 1 Hz the mean of feedback 

speed and torque at 1 Hz or more frequently. Use the dynamometer to increase torque at 

a constant rate. Increase the reference torque at a constant rate from no-load to the end 

point torque as defined in paragraph (d)(5)(i) of this section. You may map your engine 

to higher torques. Unless the standard-setting part specifies otherwise, target a torque 

sweep rate equal to the manufacturer declared test torque, or a torque derived from 

manufacturer published power level if the declared test torque is not known, divided by 

180 scomplete the map such that it takes (2 to 4) min to sweep from no-load governed 

speed to the speed below maximum mapped power at which the engine develops 90 % of 

maximum mapped power. You may map your engine to lower speeds. You may 

continue mapping at higher torque setpoints. At each setpoint, allow torque and speed to 

stabilize. Record the mean feedback speed and torque at each setpoint. Stop recording 

after you complete the sweep. Verify that the average torque sweep rate over the entire 

map is within ±7 % of the target torque sweep rate. From this series of mean feedback 

speed and torque values, use linear interpolation to determine intermediate values. Use 

this series of mean feedback speeds and torques to generate the power map as described 

in paragraph (e) of this section. 

(ii) For any constant-speed engine, you may perform an engine map with a continuous 

torque sweep by continuing to record the mean feedback speed and torque at 1 Hz or 

more frequently. Use the dynamometer to increase torque. Increase the reference torque 

at a constant rate from no-load to the endpoint torque as defined in paragraph (d)(5)(i) of 

this section. You may continue mapping at higher torque setpoints. Unless the standardsetting part specifies otherwise, target a torque sweep rate equal to the manufacturerdeclared test torque (or a torque derived from your published power level if the declared 

test torque is not known) divided by 180 s. Stop recording after you complete the sweep. 

Verify that the average torque sweep rate over the entire map is within ±7 % of the target 

torque sweep rate. Use linear interpolation to determine intermediate values from this 

series of mean feedback speed and torque values. Use this series of mean feedback 

speeds and torques to generate the power map as described in paragraph (e) of this 

section.

(iii) For electric power generation applications in which the design requirements will 

limit normal engine operation is limited to a specific speed range, map the engine with 

two points as follows.described in this paragraph (d)(5)(iii). After stabilizing at the noload governed speed in §1065.510(d)(4), record the mean feedback speed and torque. 

We recommend that you record the mean feedback speed and torque for the last (4 to 6) 

seconds. Continue to operate the engine with the governor or simulated governor 

controlling engine speed using operator demand, and control the dynamometer to target a 
speed of 97.5 % of the recorded mean no-load governed speed. If the in-use performance 

class of the electric power generation application is known, you may use those values in 

place of 97.5 % (e.g.., for ISO 8528-5 G3 Performance Class, the steady-state frequency 

band is less than or equal to 0.5 %, so use 99.75 % instead of 97.5 %). StabilizeAllow

speed and allow torque to stabilize. Record the mean feedback speed and torque. Record 

the target speed. We recommend that you stabilize for at least 15 seconds and record the 

mean feedback speed and torque for the last (4 to 6) seconds. The absolute value of the 

speed error (the mean feedback speed minus the target speed) must be no greater than 20 

% of the difference between the recorded mean no-load governed speed and the target 

speed. From this series of two mean feedback speed and torque values, use linear 

interpolation to determine intermediate values. Use this series of two mean feedback 

speeds and torques to generate a power map as described in paragraph (e) of this section. 

Note that the measured maximum test torque determined in §1065.610(b)(1), will be the 

mean feedback torque recorded on the second point. 

* * * * *

(f) * * * 

(3) * * * 

(i) You may use a declared value for maximum test speed for variable-speed engines if it 

is within (97.5 to 102.5) % of the corresponding measured value. You may use a higher 

declared speed if the length of the “vector” at the declared speed is within 2.0 % of the 

length of the “vector” at the measured value. The term vector refers to the square root of 

the sum of normalized engine speed squared and the normalized full-load power (at that 

speed) squared, consistent with the calculations in §1065.610. 

(ii) * * * 

(iii) For electronically governed engines, you may use a declared warm high-idle speed 

for calculating the alternate maximum test speed as specified in §1065.610. 

(4) * * * 

(5) Optional declared torques. (i) For variable-speed engines you may declare a

maximum torque over the engine operating range. You may use the declared value for 

measuring warm high-idle speed as specified in §1065.510. 

(ii) For constant-speed engines you may declare a maximum test torque. You may use 

the declared value for cycle generation if it is within (95 to 100) % of the measured value. 

* * * * *

(g) Mapping variable-speed engines with an electric hybrid system. Map variable-speed 

engines that include electric hybrid systems as described in this paragraph (g). You may 

ask to apply these provisions to other types of hybrid engines, consistent with good 

engineering judgment. However, do not use this procedure for engines used in hybrid 

vehicles where the hybrid system is certified as part of the vehicle rather than the engine. 

Follow the steps for mapping a variable-speed engine as given in paragraph (b)(5) of this 

section except as noted in this paragraph (g). You must generate one engine map with 

the hybrid system inactive as described in paragraph (g)(1) of this section, and a separate 

map with the hybrid system active as described in paragraph (g)(2) of this section. See 

the standard-setting part to determine how to use these maps. The map with the system 

inactive is typically used to generate steady-state duty cycles, but may also be used to 

generate transient cycles, such as those that do not involve engine motoring. This hybrid-
inactive map is also used for generating the hybrid-active map. The hybrid-active map is 

typically used to generate transient duty cycles that involve engine motoring. 

(1) Prepare the engine for mapping by either deactivating the hybrid system or by 

operating the engine as specified in paragraph (b)(4) of this section and remaining at this 

condition until the rechargeable energy storage system (RESS) is depleted. Once the 

hybrid has been disabled or the RESS is depleted, perform an engine map as specified in 

paragraph (b)(5) of this section. If the RESS was depleted instead of deactivated, ensure 

that instantaneous power from the RESS remains less than 2 % of the instantaneous 

measured power from the engine (or engine-hybrid system) at all engine speeds. 

(2) The purpose of the mapping procedure in this paragraph (g) is to determine the 

maximum torque available at each speed, such as what might occur during transient 

operation with a fully charged RESS. Use one of the following methods to generate a 

hybrid-active map:

(i) Perform an engine map by using a series of continuous sweeps to cover the engine’s 

full range of operating speeds. Prepare the engine for hybrid-active mapping by fully 

charging the RESS. Perform the sweep as specified in paragraph (b)(5)(ii) of this section, 

but stop the sweep to charge the RESS when the power measured from the RESS drops 

below the expected maximum power from the RESS by more than 2 % of total system 

power (including engine and RESS power). Unless good engineering judgment indicates 

otherwise, assume that the expected maximum power from the RESS is equal to the 

measured RESS power at the start of the sweep segment. For example, if the 3-second 

rolling average of total engine-RESS power is 200 kW and the power from the RESS at 

the beginning of the sweep segment is 50 kW, once the power from the RESS reaches 46 

kW, stop the sweep to charge the RESS. Note that this assumption is not valid where the 

hybrid motor is torque-limited. Calculate total system power as a 3-second rolling 

average of instantaneous total system power. After each charging event, stabilize the 

engine for 15 seconds at the speed at which you ended the previous segment with 

operator demand set to maximum before continuing the sweep from that speed. Repeat 

the cycle of charging, mapping, and recharging until you have completed the engine map. 

You may shut down the system or include other operation between segments to be 

consistent with the intent of this paragraph (g)(2)(i). For example, for systems in which 

continuous charging and discharging can overheat batteries to an extent that affects 

performance, you may operate the engine at zero power from the RESS for enough time 

after the system is recharged to allow the batteries to cool. Use good engineering 

judgment to smooth the torque curve to eliminate discontinuities between map intervals.

(ii) Perform an engine map by using discrete speeds. Select map setpoints at intervals 

defined by the ranges of engine speed being mapped. From 95 % of warm idle speed to 

90 % of the expected maximum test speed, select setpoints that result in a minimum of 13 

equally spaced speed setpoints. From 90 % to 110 % of expected maximum test speed,

select setpoints in equally spaced intervals that are nominally 2 % of expected maximum 

test speed. Above 110 % of expected maximum test speed, select setpoints based on the 

same speed intervals used for mapping from 95 % warm idle speed to 90 % maximum 

test speed. You may stop mapping at the highest speed above maximum power at which 

50 % of maximum power occurs. We refer to the speed at 50 % power as the check point 

speed as described in paragraph (b)(5)(iii) of this section. Stabilize engine speed at each 

setpoint, targeting a torque value at 70 % of peak torque at that speed without hybrid-
assist. Make sure the engine is fully warmed up and the RESS state of charge is within 

the normal operating range. Snap the operator demand to maximum, operate the engine 

there for at least 10 seconds, and record the 3-second rolling average feedback speed and 

torque at 1 Hz or higher. Record the peak 3-second average torque and 3-second average 

speed at that point. Use linear interpolation to determine intermediate speeds and 

torques. Follow §1065.610 (a) to calculate the maximum test speed. Verify that the 

measured maximum test speed falls in the range from 92 to 108 % of the estimated 

maximum test speed. If the measured maximum test speed does not fall in this range, 

rerun the map using the measured value of maximum test speed.

(h) Other mapping procedures. You may use other mapping procedures if you believe 

the procedures specified in this section are unsafe or unrepresentative for your engine. 

Any alternate techniques you use must satisfy the intent of the specified mapping 

procedures, which is to determine the maximum available torque at all engine speeds that 

occur during a duty cycle. Identify any deviations from this section’s mapping 

procedures when you submit data to us.

66. Section 1065.514 is amended by revising paragraph (f)(3) and Table 2 as follows: 

§1065.514 Cycle-validation criteria for operation over specified duty cycles. 

* * * * * 

(f) * * * 

(3) For discrete-mode steady-state testing, apply cycle-validation criteria by treating the 

sampling periods from the series of test modes as a continuous sampling period, 

analogous to ramped-modal testing and apply statistical criteria as described in paragraph 

(f)(1) or (2) of this section. Note that if the gaseous and particulate test intervals are 

different periods of time, separate validations are required for the gaseous and particulate 

test intervals. 

Table 2 of §1065.514—Default statistical criteria for validating duty cycles 

Parameter Speed Torque Power 

Slope, a1 0.950 ≤ a1 ≤ 1.030 0.830 ≤ a1 ≤ 1.030 0.830 ≤ a1 ≤ 1.030 

Absolute value of 

intercept, |a0| ≤ 10 % of warm idle ≤ 2.0 % of maximum mapped torque 

≤ 2.0 % of maximum 

mapped power 

Standard error of 

estimate, SEE

≤ 5.0 % of 

maximum test speed

≤ 10 % of maximum 

mapped torque 

≤ 10 % of maximum 

mapped power 

Coefficient of 

determination, r

2 ≥ 0.970 ≥ 0.850 ≥ 0.910 

* * * * * 

67. Section 1065.520 is amended by revising paragraph (g) introductory paragraph, 

paragraphs (g)(5), (g)(7) and (g)(8) adding paragraph (g)(9) to read as follows: 

§1065.520 Pre-test verification procedures and pre-test data collection.

* * * * * 

(g) Verify the amount of nonmethane hydrocarbon contamination in the exhaust and 

background HC sampling systems within 8 hours before the start of the first test interval 

of each duty-cycle sequence for laboratory tests. You may verify the contamination of a 

background HC sampling system by reading the last bag fill and purge using zero gas. 
For any NMHC measurement system that involves separately measuring methane and 

subtracting it from a THC measurement or for any CH4 measurement system that uses an 

NMC, verify the amount of THC contamination using only the THC analyzer response. 

There is no need to operate any separate methane analyzer for this verification,; however,

you may measure and correct for THC contamination in the CH4 sample train for the 

cases where NMHC is determined by subtracting CH4 from THC or, where CH4 is 

determined, using an NMC as configured in §1065.365(d), (e), and (f); and using the 

calculations in §1065.660(b)(2). Perform this verification as follows: 

(1) * * * 

(5) Measure the THC concentration in the sampling and background systems as follows: 

(i) For continuous sampling, record the mean THC concentration as overflow zero air gas 

flows. 

(ii) For batch sampling, fill the sample medium (e.g., bag) and record its mean THC 

concentration. 

(6) * * * 

(7) You may correct the measured initial THC concentration for drift as follows: 

(i) For batch and continuous HC analyzers, after determining the initial THC 

concentration, flow zero gas to the analyzer zero or sample port. When the analyzer 

reading is stable, record the mean analyzer value. 

(ii) Flow span gas to the analyzer span or sample port. When the analyzer reading is 

stable, record the mean analyzer value. 

(iii) Use mean analyzer values from paragraphs (g)(2), (3), (7)(i), and (7)(ii) of this 

section to correct the initial THC concentration recorded in paragraph (g)(6) of this 

section for drift, as described in §1065.550. 

(788) If any of the xTHC[THC-FID]init values exceed the greatest of the following values, 

determine the source of the contamination and take corrective action, such as purging the 

system during an additional preconditioning cycle or replacing contaminated portions: 

(i) 2 % of the flow-weighted mean wet, net concentration expected at the HC (THC or 

NMHC) standard. 

(ii) 2 % of the flow-weighted mean wet, net concentration of HC (THC or NMHC) 

measured during testing. 

(iii) 2 μmol/mol. 

(899) If corrective action does not resolve the deficiency, you may request to use the 

contaminated system as an alternate procedure under §1065.10. 

* * * * *

* * * * *

68. Section 1065.525 is amended by revising paragraph (a) and removing paragraph 

(c)(4). 

§1065.525 Engine starting, restarting, and shutdown. 

(a) For test intervals that require emission sampling during engine starting, sStart the 

engine using one of the following methods: 

(1) Start the engine as recommended in the owners manual using a production starter 

motor or air-start system and either an adequately charged battery, a suitable power 

supply, or a suitable compressed air source. 
(2) Use the dynamometer to start the engine. To do this, motor the engine within ±25 % 

of its typical in-use cranking speed. Stop cranking within 1 second of starting the engine. 

(3) In the case of hybrid engines, activate the system such that the engine will start when 

its control algorithms determine that the engine should provide power instead of or in 

addition to power from the RESS. Unless we specify otherwise, engine starting 

throughout this part generally refers to this step of activating the system on hybrid 

engines, whether or not that causes the engine to start running.

* * * * * 

(c) * * * 

(4) DELETE 

* * * * * 

69. Section 1065.530 is amended by revising paragraph (b)(13) to read as follows: 

§1065.530 Emission test sequence. 

* * * * * 

(b) * * * 

(13) Drain any accumulated condensate from the intake air system before starting a duty 

cycle, as described in §1065.125(e)(1). If engine and aftertreatment preconditioning 

cycles are run before the duty cycle, treat the preconditioning cycles and any associated 

soak period as part of the duty cycle for the purpose of opening drains and draining 

condensate. Note that you must and close any intake air condensate drains that are not 

representative of those normally open during in-use operation. 

* * * * *

* * * * *

70. Section 1065.546 is amended by revising paragraph (a) to read as follows: 

§1065.546 Validation of minimum dilution ratio for PM batch sampling, and drift 

correction. 

* * * * * 

(a) Determine minimum dilution ratio based on molar flow data. This involves 

determination of at least two of the following three quantities: raw exhaust flow (or 

previously diluted flow), dilution air flow, and dilute exhaust flow. You may determine 

the raw exhaust flow rate based on the measured intake air or fuel flow rate and the raw 

exhaust chemical balance terms as given in §1065.655(e). You may determine the raw 

exhaust flow rate based on the measured intake air and dilute exhaust molar flow rates 

and the dilute exhaust chemical balance terms as given in §1065.655(f). You may 

alternatively estimate the molar raw exhaust flow rate based on intake air, fuel rate 

measurements, and fuel properties, consistent with good engineering judgment. 

* * * * * 

71. Section 1065.550 is amended by revising the section title and paragraph (b) to read 

as follows: 

§1065.550 Gas analyzer range validation, and drift validation, and drift correction. 

* * * * * 
(b) Drift validation and drift correction. Calculate two sets of brake-specific emission 

results for each test interval. Gas analyzer drift validation is required for all gaseous 

exhaust constituents for which a brake-specific emissions an emission standard applies. 

It is also required for CO2 even if there is no brake-specific CO2 emission standard

applies. It is not required for other gaseous exhaust constituents for which only a 

reporting requirement applies (e.g. brake-specific such as CH4 and N2O). 

(1) Depending on how a regulated constituent is determined, Validate drift as 

followsusing one of the following methods: 

(i) For regulated exhaust constituents determined from the mass of a single component, 

perform drift validation based on the regulated constituent. For example, when NOx

mass is determined with a dry sample measured with a CLD and the removed water is 

corrected based on measured CO2, CO, THC, and NOx concentrations;, you must validate 

the calculated NOx value. 

(ii) For regulated exhaust constituents determined from the masses of multiple 

subcomponents, perform the drift validation based on either the regulated constituent or 

all the mass subcomponents. For example, when NOx is measured with separate NO and 

NO2 analyzers, you must validate either the NOx value or both the NO and NO2 values. 

(iii) For regulated exhaust constituents determined from the concentrations of multiple 

gaseous emissions subcomponents prior to performing mass calculations (e.g., NMHC),,

perform drift validation on the regulated constituent. You may not validate the 

concentration subcomponents (e.g., THC and CH4 for NMHC) separately. For example, 

for NMHC measurements, perform drift validation on NMHC; do not validate THC and 

CH4 separately.

(2) Drift validation requires two sets of emissions calculations. For each set includesof 

calculations, include all of the constituents to be validated forin the drift validation. 

Calculate one set using the data before drift correction and calculate the other set after 

correcting all the data for drift according to §1065.672. Use the two sets of brakespecific emission results to validate the duty cycle for drift as follows:

(1) The duty cycle is validated for drift if you satisfy one of the following criteria:

(i) For each test interval of the duty cycle and for each measured exhaust constituent, the 

difference between the uncorrected and the corrected brake-specific emission values over 

the test interval is within ±4 % of the uncorrected value or applicable emission standard, 

whichever is greater. This requirement also applies for CO2, whether or not an emission 

standard applies for CO2. Where no emission standard applies for CO2, the difference 

must be within ±4 % of the uncorrected value. See paragraph (b)(4) of this section for 

exhaust constituents other than CO2 for which no emission standard applies.

(ii) For the entire duty cycle and for each measured exhaust constituent, the difference 

between the uncorrected and corrected composite brake-specific emission values over the 

entire duty cycle is within ±4 % of the uncorrected value or the applicable emission 

standard, whichever is greater. Note that for purposes of drift validation using composite 

brake-specific emission values over the entire duty cycle, Note that for purposes of drift 

validation, you must leave unaltered any negative emission results over a given test 

interval (i.e., do not set them to zero). These unaltered results are used when validating 

either test interval results or composite brake-specific emissions over the entire duty 

cycle for drift. For each constituent to be validated, both sets of calculations must 

include the following: 
(i) Calculated mass (or mass rate) emission values over each test interval. 

(ii) If you are validating each test interval based on brake-specific values, calculate brakespecific emission values over each test interval. 

(iii) If you are validating over the entire duty cycle, calculate composite brake-specific 

emission values. A third calculation of composite brake-specific emission values is 

required for final reporting. This calculation uses drift-corrected mass (or mass rate) 

values from each test interval and sets any negative mass (or mass rate) values to zero 

before calculating the composite brake-specific emission values over the entire duty 

cycle. This requirement also applies for CO2, whether or not an emission standard 

applies for CO2. Where no emission standard applies for CO2, the difference must be 

within ±4 % of the uncorrected value. See paragraph (b)(4) of this section for exhaust 

constituents other than CO2 for which no emission standard applies.

(23(iii) If you are validating over the entire duty cycle, calculate composite brake-specific 

emission values.

(3) Validation Criteria. For standards consisting of combined, individual measurements 

of exhaust constituents (such as NOx + NMHC or separate NO and NO2 measurements to 

comply with a NOx standard), tThe duty cycle shall beis The duty cycle is validated for 

drift if you satisfy one of the following criteria: 

(i) For each test interval of the duty cycle and for each individually measuredregulated 

regulated gaseous exhaust constituent (e.g. NO, NO2, NOx, or NMHC),, you must satisfy 

one of the following: 

(A) For each test interval of the duty cycle you must satisfy one of the following:

(1) Tthe, the difference between the uncorrected and the corrected brake-specific 

emission values over of the regulated constituent must be test interval is within ±4 % of 

the uncorrected value; or the applicable emissions standard, whichever is greater; (ii) For 

each test interval of. Alternatively, the duty cycle or

(2) for the entire duty cycle Tthe difference between the combined (e.g. NOx + NMHC) 

uncorrected and combined (e.g. NOx + NMHC) the corrected composite brake-specific 

emissionsemission mass (or mass rate) values of the regulated constituent must be over 

each test interval of the duty cycle or the entire duty cycle is within ±4 % of the 

uncorrected value or the composite work (or power) multiplied by the applicable 

emissions standard, whichever is greater. For purposes of validating each test interval, 

you may use either the reference or actual composite work (or power). 

(B) For each test interval of the duty cycle and for each subcomponent of the regulated 

constituent you must satisfy one of the following:, the difference between the uncorrected 

and the corrected brake-specific emission values must be within ±4 % of the uncorrected 

value. Alternatively, the difference between the uncorrected and the corrected emissions 

mass (or mass rate) values must be within ±4 % of the uncorrected value.

(1) The difference between the uncorrected and the corrected brake-specific emission 

values must be within ±4 % of the uncorrected value; or

(2) The difference between the uncorrected and the corrected emissions mass (or mass 

rate) values must be within ±4 % of the uncorrected value.

(C) For the entire duty cycle, the difference between the uncorrected and the corrected 

composite brake-specific emission values of the regulated constituent must be within ±4 

% of the uncorrected value or applicable emission standard, whichever is greater. 
(D) For the entire duty cycle and for each subcomponent of the regulated constituent, the 

difference between the uncorrected and the corrected composite brake-specific emission 

values must be within ±4 % of the uncorrected value. 

(ii) Where no emission standard applies for CO2, you must satisfy one of the following: 

(A) For each test interval of the duty cycle, the difference between the uncorrected and 

the corrected brake-specific CO2 values must be within ±4 % of the uncorrected value; or 

the difference between the uncorrected and the corrected CO2 mass (or mass rate) values 

must be within ±4 % of the uncorrected value. 

(B) For the entire duty cycle, the difference between the uncorrected and the corrected 

composite brake-specific CO2 values must be within ±4 % of the uncorrected value. 

(322) If the test is not validated for drift as described in paragraph (b)(1) of this section, 

you may consider the test results for the duty cycle to be valid only if, using good 

engineering judgment, the observed drift does not affect your ability to demonstrate 

compliance with the applicable emission standards. For example, if the drift-corrected 

value is less than the standard by at least two times the absolute difference between the 

uncorrected and corrected values, you may consider the data to be valid for 

demonstrating compliance with the applicable standard. 

(4) The provisions of this paragraph (b)(4) apply for measurement of pollutants other 

than CO2 for which no emission standard applies (for purposes of this provision, 

standards consisting of combined, individual measurements are considered to be 

standards for each individual pollutant). You may use measurements that do not meet the 

drift validation criteria specified in paragraph (b)(1). For example, this allowance may be 

appropriate for measuring and reporting very low concentrations of CH4 and N2O as long 

as no emission standard applies for these compounds. 

* * * * *

* * * * *

Subpart G—[Amended] 

72. Section 1065.602 is amended by revising paragraph (f)(3) before the table, 

paragraph (h), and paragraphs (l)(1)(ii) and (iii) as follows: 

§1065.602 Statistics. 

* * * * * 

(f) * * * 

(3) Use Table 1 of this section to compare t to the tcrit values tabulated versus the number 

of degrees of freedom. If t is less than tcrit, then t passes the t-test. The Microsoft Excel 

software package containshas a TINV function that returns results equivalent to Table 1 

of §1065.602 Table 1 results and may be used in place of Table 1., which follows:

* * * * *

(h) Slope. Calculate a least-squares regression slope, a1y, as follows:
( ) i refi ref

i 1

1y

2

refi ref

i 1

( )

( )

N

N

y y y y

a

y y

=

=

− ⋅ −

=

−

∑

∑

Eq. 1065.602-9

Example:

N = 6000

y1 = 2045.8

y = 1050.1

yref 1 = 2045.0

ref y = 1055.3

( ) ( ) ( ) ( )

( ) ( )

6000 ref6000

1y 2 2

ref6000

2045.8 1050.1 2045.0 1055.3 ... 1050.1 1055.3

2045.0 1055.3 ... 1055.3

y y

a

y

− ⋅ − + + − ⋅ −

=

− + + −

a1y = 1.0110

* * * * *

(l) * * * 

(1) * * * 

(ii) Based on your engine design, estimate maximum power, Pmax, the design speed at 

maximum power, fnmax, the design maximum intake manifold boost pressure, pinmax, and 

temperature, Tinmax. Also, estimate a mean fraction of power that is lost due to friction 

and pumping, Pfrict . Use this information along with the engine displacement volume, 

Vdisp, an approximate volumetric efficiency, ηV, and the number of engine strokes per 

power stroke (2-stroke or 4-stroke), Nstroke, to estimate the maximum raw exhaust molar 

flow rate, exhmax n . 

(iii) Use your estimated values as described in the following example calculation: 

( )

std ref

exp

ref frict max

exhmax duty cycle

max

e W

x

P P P

M n t

P

⋅

=

  + ⋅

⋅ ⋅ ∆ ⋅ 

 



( )

std ref

exp

ref frict max

exhmax duty cycle

max

e W

x

P P P

M n t

P

⋅

=

  + ⋅

⋅ ⋅ ∆ ⋅ 

 



Eq. 1065.602-13 

max disp nmax V

stroke

exhmax

max

2

p V f

N

n

R T

⋅ ⋅ ⋅ ⋅η

=

⋅


max disp nmax V

stroke

exhmax

max

2

p V f

N

n

R T

⋅ ⋅ ⋅ ⋅η

=

⋅



Eq. 1065.602-14 

Example:

eNOx = 2.5 g/(kW·hr) 

Wref = 11.883 kW·hr 

MNOx = 46.0055 g/mol = 46.0055·10-6 g/μmol 

∆tdutycycle = 20 min = 1200 s 

Pref = 35.65 kW 

Pfrict = 15 % 

Pmax = 125 kW 

pmax = 300 kPa = 300000 Pa 

Vdisp = 3.0 l = 0.0030 m3/r 

fnmax = 2800 revr/min = 46.67 revr/s 

Nstroke = 4 1/rev

ηV= 0.9 

R = 8.314472 J/(mol·K) 

Tmax = 348.15 K 

exhmax

2

300000 0.0030 46.67 0.9

4

8.314472 348.15

n

⋅ ⋅ ⋅ ⋅

=

⋅



exhmax

2

300000 0.0030 46.67 0.9

4

8.314472 348.15

n

⋅ ⋅ ⋅ ⋅

=

⋅



nexhmax  = 6.53 mol/s 

( ) exp

6

2.5 11.883

35.65 0.15 125

46.0055 10 6.53 1200

125

x

−

⋅

=

  + ⋅

⋅ ⋅ ⋅ ⋅   

( ) exp

6

2.5 11.883

35.65 0.15 125

46.0055 10 6.53 1200

125

x

−

⋅

=

  + ⋅

⋅ ⋅ ⋅ ⋅   

exp x = 189.4 μmol/mol 

73. Section 1065.610 is amended by revising paragraphs (a)(1), (a)(2), (a)(3), (b)(1), 

(c)(1), (c)(2), and (c)(3) and adding a new (a)(4) as follows: 

§1065.610 Duty cycle generation. 
* * * * * 

(a) * * * 

(1) Based on the map, determine maximum power, Pmax, and the speed at which 

maximum power occurred, fnPmax. If maximum power occurs at multiple speeds, take

fnPmax as the lowest of these speeds. Divide every recorded power by Pmax and divide 

every recorded speed by fnPmax. The result is a normalized power-versus-speed map. 

Your measured fntest is the speed at which the sum of the squares of normalized speed and 

power is maximum. Note that if multiple maximum values are found, fntest should be 

taken as the lowest speed of all points with the same maximum sum of squares. 

Determine fntest as follows: 

( )

2 2

ntest ni nnormi normi f f f P = + at the maximum of 

( )

2 2

ntest ni nnormi normi f f f P = + at the maximum of 

Eq. 1065.610-1 

Where: 

fntest = maximum test speed. 

i = an indexing variable that represents one recorded value of an engine map. 

fnnormi = an engine speed normalized by dividing it by fnPmax. 

Pnormi = an engine power normalized by dividing it by Pmax. 

Example:

(fnnorm1 = 1.002, Pnorm1 = 0.978, fn1 = 2359.71) 

(fnnorm2 = 1.004, Pnorm2 = 0.977, fn2 = 2364.42) 

(fnnorm3 = 1.006, Pnorm3 = 0.974, fn3 = 2369.13) 

(fnnorm1

2

 + Pnorm1

2

) = (1.0022 + 0.9782) = 1.960 

(fnnorm2

2

 + Pnorm2

2

) = (1.0042 + 0.9772) = 1.963 

(fnnorm3

2

 + Pnorm3

2

) = (1.0062 + 0.9742) = 1.961 

maximum = 1.963 at i = 2 

fntest = 2364.42 revr/min 

(2) For engines with a high-speed governor that will be subject to a reference duty cycle 

that specifies normalized speeds greater than 100 %, calculate an alternate maximum test 

speed, fntest,alt, as specified in this paragraph. (a)(2). If the alternate maximum test speed, 

fntest,alt, is less than the measured maximum test speed, fntest, determined in paragraph 

(a)(1) of this section, replace fntest with fntest,alt. This alternate maximum test speed In this 

case, fntest,alt becomes the “maximum test speed” for that engine. You mayNote that 

§1065.510 allows you to apply an optional declared maximum test speed, as specified in 

§1065.510, to the final measured maximum test speed (i.e. the lower of fntest, determined 

in paragraph (a)(1) of this sectionas an outcome of the comparison between fntest, and 

fntest,alt determined in this paragraph). This paragraph does not apply if the duty cycle

does not include reference speeds greater than 100 % of maximum test speed such as the 

transient test cycles specified in 40 CFR 86.1330-2010 and 1048.510. (a)(2). Determine 

fntest,alt as follows: 

fntest,alt = (fnhi,idle – fnidle)/% speedmax + fnidle

Eq. 1065.610-2 
Where: 

fntest,alt = alternate maximum test speed 

fnhi,idle = warm high-idle speed 

fnidle = warm idle speed 

% speedmax = maximum normalized speed from duty cycle 

Example: 

fnhi,idle = 2200 r/min 

fnidle = 800 r/min 

% speedmax = 105 % (Nonroad CI Transient Cycle) 

fntest,alt = (2200 – 800)/105 % + 800 

fntest,alt = 2133 r/min 

(3) For variable-speed engines, transform normalized speeds to reference speeds 

according to paragraph (c) of this section by using the measured maximum test speed 

determined according to paragraphs (a)(1) and (a)(2) of this section—or use your 

declared maximum test speed, as allowed in §1065.510. 

(344) For constant-speed engines, transform normalized speeds to reference speeds 

according to paragraph (c) of this section by using the measured no-load governed 

speed—or use your declared maximum test speed, as allowed in §1065.510 

(b) * * * 

(1) Based on the map, determine maximum power, Pmax, and the speed at which 

maximum power occurs, fnPmax. If maximum power occurs at multiple speeds, take fnPmax

as the lowest of these speeds. Divide every recorded power by Pmax and divide every 

recorded speed by fnPmax. The result is a normalized power-versus-speed map. Your 

measured Ttest is the torque at which the sum of the squares of normalized speed and 

power is maximum. Note that that if multiple maximum values are found, Ttest should be 

taken as the highest torque of all points with the same maximum sum of squares. 

Determine Ttest as follows: 

( )

2 2

test i nnormi normi T T f P = + at the maximum of 

( )

2 2

test i nnormi normi T T f P = + at the maximum of 

Eq. 1065.610-233

Where: 

Ttest = maximum test torque. 

Example:

(fnnorm1 = 1.002, Pnorm1 = 0.978, T1 = 722.62 N·m)

(fnnorm2 = 1.004, Pnorm2 = 0.977, T2 = 720.44 N·m)

(fnnorm3 = 1.006, Pnorm3 = 0.974, T3 = 716.80 N·m)

(fnnorm1

2

 + Pnorm1

2

) = (1.0022 + 0.9782) = 1.960 

(fnnorm1

2

 + Pnorm1

2

) = (1.0042 + 0.9772) = 1.963 

(fnnorm1

2

 + Pnorm1

2

) = (1.0062 + 0.9742) = 1.961 

maximum = 1.963 at i = 2 

Ttest = 720.44 N·m 
(2) * * * 

(c) * * * 

(1) % speed. If your normalized duty cycle specifies % speed values, use your warm idle 

speed and your maximum test speed to transform the duty cycle, as follows: 

fnref = % speed · (fntest – fnidle) + fnidle

Eq. 1065.610-344

Example:

% speed = 85 % 

fntest = 2364 revr/min 

fnidle = 650 revr/min 

fnref = 85 % · (2364 – 650 ) + 650 

fnref = 2107 revr/min 

(2) A, B, and C speeds. If your normalized duty cycle specifies speeds as A, B, or C 

values, use your power-versus-speed curve to determine the lowest speed below 

maximum power at which 50 % of maximum power occurs. Denote this value as nlo. 

Take nlo to be warm idle speed if all power points at speeds below the maximum power 

speed are higher than 50 % of maximum power. Also determine the highest speed above 

maximum power at which 70 % of maximum power occurs. Denote this value as nhi. If 

all power points at speeds above the maximum power speed are higher than 70% of 

maximum power, take nhi to be the declared maximum safe engine speed or the declared 

maximum representative engine speed, whichever is lower. Use nhi and nlo to calculate 

reference values for A, B, or C speeds as follows: 

fnrefA = 0.25 · (nhi – nlo) + nlo

Eq. 1065.610-455

fnrefB = 0.50 · (nhi – nlo) + nlo

Eq. 1065.610-566

fnrefC = 0.75 · (nhi – nlo) + nlo

Eq. 1065.610-677

Example:

nlo = 1005 revr/min 

nhi = 2385 revr/min 

fnrefA = 0.25 · (2385 – 1005) + 1005 

fnrefB = 0.50 · (2385 – 1005) + 1005 

fnrefC = 0.75 · (2385 – 1005) + 1005 

fnrefA = 1350 revr/min 

fnrefB = 1695 revr/min 

fnrefC = 2040 revr/min 

(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 2.0 % of 

the maximum recorded value. Identify your reference intermediate speed as one of the 

following values: 

* * * * * 
74. Section 1065.640 is amended by revising paragraphs (b)(1), (b)(2), (b)(5), (e)(3), 

(e)(4), and (e)(7) as follows: 

§1065.640 Flow meter calibration calculations. 

* * * * * 

(b) * * * 

(1) PDP volume pumped per revolution, Vrev (m3/revr): 

ref in

rev

in nPDP

n R T V

P f

⋅ ⋅

=

⋅



ref in

rev

in nPDP

n R T V

P f

⋅ ⋅

=

⋅



Eq. 1065.640-2 

Example:

ref n = 25.096 mol/s 

R = 8.314472 J/(mol·K) 

Tin = 299.5 K 

Pin = 98290 Pa 

nPDP f = 1205.1 revr/min = 20.085 revr/s 

25.096 8.314472 299.5

98290 20.085

Vrev

⋅ ⋅

=

⋅

25.096 8.314472 299.5

98290 20.085

Vrev

⋅ ⋅

=

⋅

Vrev = 0.03166 m3/revr

(2) PDP slip correction factor, Ks (s/revr): 

out in

s

nPDP out

1 P P K

f P

−

= ⋅

out in

s

nPDP out

1 P P K

f P

−

= ⋅

Eq. 1065.640-3 

Example:

nPDP f = 1205.1 revr/min = 20.085 revr/s 

Pout = 100.103 kPa 

Pin = 98.290 kPa 

s

1 100.103 98.290

20.085 100.103

K

−

= ⋅

s

1 100.103 98.290

20.085 100.103

K

−

= ⋅

Ks = 0.006700 s/revr
(3) * * * 

(4) * * * 

(5) The following example illustrates these calculations: 

Table 1 of §1065.640– 

Example of PDP calibration data 

nPDP f

(revr/min) 

a1 

(m3/min)

a0 

(m3/revr)

755.0 50.43 0.056 

987.6 49.86 -0.013 

1254.5 48.54 0.028 

1401.3 47.30 -0.061 

(e) * * * 

(3) If the standard deviation of all the Cd values is less than or equal to 0.3 % of the mean 

Cd, use the mean Cd in Eq 1065.642-6, and use the CFV only up to the highest r

measured during calibration using the following equation: 

CFV

in

1

p

r

p

∆

= −

CFV

in

1

p

r

p

∆

= −

Eq. 1065.640-13 

Where: 

∆pCFV = Differential static pressure; venturi inlet minus venturi outlet. 

(4) If the standard deviation of all the Cd values exceeds 0.3 % of the mean Cd, omit the 

Cd values corresponding to the data point collected at the highest r measured during 

calibration. 

* * * * * 

(7) If the standard deviation of the remaining Cd values is less than or equal to 0.3 % of 

the mean of the remaining Cd, use that mean Cd in Eq 1065.642-6, and use the CFV 

values only up to the highest r associated with the remaining Cd. 

* * * * * 

75. Section 1065.642 is amended by revising paragraph (a) as follows: 

§1065.642 SSV, CFV, and PDP molar flow rate calculations. 

* * * * * 

(a) PDP molar flow rate. Based upon the speed at which you operate the PDP for a test 

interval, select the corresponding slope, a1, and intercept, a0, as calculated in §1065.640, 

to calculate molar flow rate, n as follows: 

nPDP

in rev

in

p V n f

R T

⋅

= ⋅

⋅


nPDP

in rev

in

p V n f

R T

⋅

= ⋅

⋅



Eq. 1065.642-1 

Where: 

nPDP

1 out in

rev 0

out

a p p V a

f p

−

= ⋅ + nPDP

1 out in

rev 0

out

a p p V a

f p

−

= ⋅ +

Eq. 1065.642-2 

Example: 

a1 = 50.43 (m3/min) = 0.8405 (m3/s) 

nPDP f = 755.0 revr/min = 12.58 revr/s 

pout = 99950 Pa 

pin = 98575 Pa 

a0 = 0.056 (m3/revr) 

R = 8.314472 J/(mol·K) 

Tin = 323.5 K 

Cp = 1000 (J/m3

)/kPa 

Ct = 60 s/min 

rev

0.8405 99950 98575 0.056

12.58 99950

V

−

= ⋅ +

rev

0.8405 99950 98575 0.056

12.58 99950

V

−

= ⋅ +

Vrev = 0.06383 m3/revr

98575 0.06383 12.58

8.314472 323.5

n

⋅

= ⋅

⋅



98575 0.06383 12.58

8.314472 323.5

n

⋅

= ⋅

⋅



n = 29.428 mol/s 

* * * * * 

76. Section 1065.645 is amended by revising the introductory paragraph and paragraph 

(a) as follows: 

§1065.645 Amount of water in an ideal gas. 

This section describes how to determine the amount of water in an ideal gas, which you 

need for various performance verifications and emission calculations. Use the equation 

for the vapor pressure of water in paragraph (a) of this section or another appropriate 

equation and, depending on whether you measure dewpoint or relative humidity, perform 

one of the calculations in paragraph (b) or (c) of this section. Note thatThe equations for

the vapor pressure of water equations as presented in this section are derived from 

equations in “Saturation Pressure of Water on the New Kelvin Temperature Scale” 

(GoreGoff, J.A., Transactions American Society of Heating and Air-Conditioning 

Engineers, Vol. 63, No. 1607, pages 347 – 354). Note also that the equations were 
originally published to derive vapor pressure in units of atmospheres and have been 

modified to derive results in units of kPa by converting the last term in each equation. 

(a) Vapor pressure of water. Calculate the vapor pressure of water for a given saturation 

temperature condition, Tsat, as follows, or use good engineering judgment to use a 

different relationship of the vapor pressure of water to a given saturation temperature 

condition: 

(1) For humidity measurements made at ambient temperatures from (0 to 100) °C, or for 

humidity measurements made over super-cooled water at ambient temperatures from (–

50 to 0) °C, use the following equation: 

sat

sat

8 2969 1

sat 4 273.16

10 H2O 10

sat

273.16 4.76955 1

3

. 273.16 log ( ) 10.79574 1 5.02800 log 1.50475 10 1 10

273.16

0.42873 10 10 1 0.2138602

T

T

T

p

T

 

− ⋅ −  

−  

 

⋅ −  

−  

     

= ⋅ − − ⋅ + ⋅ ⋅ −             

 

+ ⋅ ⋅ − −  

 

Eq. 1065.645-1 

Where: 

pH20 = vapor pressure of water at saturation temperature condition, kPa. 

Tsat = saturation temperature of water at measured conditions, K. 

Example:

Tsat = 9.5 °C 

Tdsat = 9.5 + 273.15 = 282.65 K 

282.65 8.2969 1

4 273.16

10 H2O 10

273.16 4.76955 1

3 282.65

273.16 282.65 log ( ) 10.79574 1 5.02800 log 1.50475 10 1 10

282.65 273.16

0.42873 10 10 1 0.2138602

p

 

− ⋅ −  

−  

 

⋅ −  

−  

     

= ⋅ − − ⋅ + ⋅ ⋅ −            

 

+ ⋅ ⋅ − −  

 

log10(pH20) = 0.074297 

pH20 = 100.074297 = 1.186581 kPa 

(2) For humidity measurements over ice at ambient temperatures from (–100 to 0) °C, use 

the following equation: 

10 H2O 10

sat sat

sat

273.16 273.16 log ( ) 9.096853 1 3.566506 log

0.876812 1 0.2138602

273.16

p

T T

T

   

= − ⋅ − − ⋅        

 

+ ⋅ − −    

Eq. 1065.645-2 

Example:

Tice = –15.4 °CTice = –15.4 °C

Tice = –15.4+ 273.15 = 257.75 K 

Field Code Changed

Field Code Changed

Field Code Changed
10 H2O 10

273.16 273.16 log ( ) 9.096853 1 3.566506 log

257.75 257.75

257.75 0.876812 1 0.2138602

273.16

p

   

= − ⋅ − − ⋅        

 

+ ⋅ − −    

log10(pH20) = –0.798207 

pH20 = 10 –0.79821 = 0.159145 kPa 

* * * * * 

77. Section 1065.650 is amended by revising paragraphs (c) introductory text, (c)(1), 

(c)(4), (d)(7), (e)(4), (f)(4), and adding paragraph (c)(5) to read as follows: 

§1065.650 Emission calculations. 

* * * * * 

(c) Total mass of emissions over a test interval. To calculate the total mass of an 

emission, multiply a concentration by its respective flow. For all systems, make 

preliminary calculations as described in paragraph (c)(1) of this section, then to correct 

concentrations. Next, use the method in paragraphs (c)(2) through (4) of this section that 

is appropriate for your system. Finally, make calculations forif necessary, calculate the 

mass of NMHC as described in paragraph (c)(5) of this section for all systems. Calculate 

the total mass of emissions as follows: 

(1) Concentration corrections. Perform the following sequence of preliminary 

calculations on recorded concentrations: 

(i) Correct all gaseous emissions analyzer concentration readings, including continuous 

readings, sample bag readings, and dilution air background readings, for drift as 

described in §1065.672. Note that you must omit this step is skipped on the initial set of 

calculations where brake-specific emissions are calculated without the drift correction for 

performing the drift validation peraccording to §1065.550(b). When applying the initial 

THC and CH4 contamination readings taken peraccording to §1065.520(g), use the same 

values for both sets of calculations. You may also use as-measured values in the initial 

set of calculations and corrected values in the drift-corrected set of calculations as 

described in §1065.520(g)(7). 

(ii) Correct all THC and CH4 concentrations, including continuous readings, sample bags 

readings, and dilution air background readings, for initial contamination, as described in 

§1065.660(a). 

(iii) Correct all concentrations measured on a “dry” basis to a “wet” basis, including 

dilution air background concentrations, as described in §1065.659. 

(iiiiviv) Calculate all THC and NMHC and CH4 concentrations, including dilution air 

background concentrations, as described in §1065.660. 

(ivv) For emission testing with an oxygenated fuel, calculate any HC concentrations, 

including dilution air background concentrations, as described in §1065.665. See subpart 

I of this part for testing with oxygenated fuels. 

(vi) Correct all the NOx concentrations, including dilution air background concentrations, 

for intake-air humidity as described in §1065.670. 

(vi) Compare the background corrected mass of NMHC to background corrected mass of 

THC. If the background corrected mass of NMHC is greater than 0.98 times the 

background corrected mass of THC, take the background corrected mass of NMHC to be 

Field Code Changed
0.98 times the background corrected mass of THC. If you omit the NMHC calculations 

as described in §1065.660(b)(1), take the background corrected mass of NMHC to be 

0.98 times the background corrected mass of THC.

(vii) Calculate brake-specific emissions before and after correcting for drift, including 

dilution air background concentrations, according to §1065.672.

* * * * * 

(4) Additional provisions for diluted exhaust sampling; continuous or batch. The 

following additional provisions apply for sampling emissions from diluted exhaust: 

(i) For sampling with a constant dilution ratio, (DR),, of diluted exhaust versus exhaust 

flow (e.g., secondary dilution for PM sampling), calculate m using the following 

equation: 

m = mdil · (mPM = mPMdil · DR)

Eq. 1065.650-9 

Example:

mPMdil = 6.853 g 

DR = 6:1 

mPM = 6.853 · (6)

mPM = 41.118 g 

(ii) For continuous or batch sampling, you may measure background emissions in the 

dilution air. You may then subtract the measured background emissions, as described in 

§1065.667. 

(5) Mass of NMHC. Compare the corrected mass of NMHC to corrected mass of THC. 

If the corrected mass of NMHC is greater than 0.98 times the corrected mass of THC, 

take the corrected mass of NMHC to be 0.98 times the corrected mass of THC. If you 

omit the NMHC calculations as described in §1065.660(b)(1), take the corrected mass of 

NMHC to be 0.98 times the corrected mass of THC. 

* * * * * 

(d) * * * 

(7) Integrate the resulting values for power over the test interval. Calculate total work as 

follows: 

i

i 1

N

W P t

=

= ⋅ ∆ ∑

Eq. 1065.650-10 

Where: 

W = total work from the primary output shaft 

Pi

 = instantaneous power from the primary output shaft over an interval i. 

Pi = fni · Ti

Eq. 1065.650-11 

Example:

N = 9000 

fn1 = 1800.2 revr/min 

fn2 = 1805.8 revr/min 

T1 = 177.23 N·m 

T2 = 175.00 N·m 

Crev = 2·π rad/revr
Ct1 = 60 s/min 

Cp = 1000 (N·m·rad/s)/kW

frecord = 5 Hz 

Ct2 = 3600 s/hr 

1

1800.2 177.23 2 3.14159

60 1000

P

⋅ ⋅ ⋅

=

⋅

P1 = 33.41 kW 

P2 = 33.09 kW 

Using Eq. 1065.650-5, 

∆t = 1/5 = 0.2 s 

9000 (33.41 33.09 ... ) 0.2

3600

P

W

+ + + ⋅

=

W = 16.875 kW·hr 

* * * * * 

(e) * * * 

(4) The following example shows how to calculate mass of emissions using mean mass 

rate and mean power:

MCO = 28.0101 g/mol 

CO x = 12.00 mmol/mol = 0.01200 mol/mol 

n = n = 1.530 mol/s 

n

f = 3584.5 revr/min = 375.37 rad/s 

T = 121.50 N·m 

m = ⋅ ⋅ 28.0101 0.01200 1.530

m = 0.514 g/s = 1850.4 g/hr 

P = ⋅ 121.5 375.37

P = 45607 W 

P = 45.607 kW 

eCO = 1850.4/45.61 

eCO = 40.57 g/(kW·hr) 

* * * * * 

(f) * * * 

(4) Example. The following example shows how to calculate mass of emissions using 

proportional values: 

N = 3000 

frecord = 5 Hz 

efuel = 285 g/(kW·hr) 

wfuel = 0.869 g/g 

Mc = 12.0107 g/mol 

1

n

 = 3.922 ~mol/s = 14119.2 mol/hr 

xCcombdry1 = 91.634 mmol/mol = 0.091634 mol/mol 

xH2Oexh1 = 27.21 mmol/mol = 0.02721 mol/mol 

Using Eq. 1065.650-5, 

∆t = 0.2 s 
2 Ccombdry2 3000 Ccombdry3000

H2Oexh2 H2Oexh3000

3.922 0.091634 12.0107 ... 0.2

1 0.02721 1 1

285 0.869

n x n x

x x

W

 ⋅ ⋅ ⋅ 

+ + + ⋅  

+ + +  

=

⋅

 



W= 5.09 (kW·hr) 

* * * * * 

78. Section 1065.655 is amended by adding a new paragraph (f) and revising paragraphs 

(b)(1), (b)(2), (b)(3), (c)(5), (d)(1), and (e)(3) as follows: 

§1065.655 Chemical balances of fuel, intake air, and exhaust. 

* * * * * 

(b) * * * 

(1) A value proportional to total work, Wwhen you choose to determine brake-specific 

emissions as described in §1065.650(f). 

(2) The amount of water in a raw or diluted exhaust flow, xH2Oexh, when you do not 

measure the amount of water to correct for the amount of water removed by a sampling 

system. Correct for removed water according to §1065.659(c)(2)..

(3) The calculated dilution air flow-weighted mean fraction of dilution air in diluted 

exhaust, xdil/exh, when you do not measure dilution air flow to correct for background 

emissions as described in §1065.667(c) and (d). Note that if you use chemical balances 

for this purpose, you are assuming that your exhaust is stoichiometric, even if it is not. 

(c) * * * 

(5) The following example is a solution for xdil/exh, xH2Oexh, and xCcombdry using the 

equations in paragraph (c)(4) of this section: 

dil/exh

0.184 1 0.822 35.37 1

1000

x mol mol = − =

+

H2Oexh

35.37 34.16 35.37 1+

1000

x mmol mol = =

Ccombdry

29.3 47.6 0.371 0.369 0.0252 0.851 0.172 0.0249

1000000 1000000 1000 1000

x = + + − ⋅ − ⋅ = mol mol

( )

H2dry

29.3 0.034 0.012 0.851

8.5

25.2 0.371 3.5 0.851

1000 1000

x μmol mol

⋅ − ⋅

= =  

⋅ − ⋅    

H2Oexhdry

1.8 47.6 8.5 0.0249 0.012 0.851 0.017 0.172 0.0353

2 1000000 1000000

x mol mol  

= − + ⋅ + ⋅ − =    

dil/exhdry

0.822 0.851

1-0.034

x mol mol = =

int/exhdry

1.8 47.6 0.050 2 2 0.0003 0.0249

1 2 1000000

0.172

2 0.206 29.3 50.4 12.1 8.5 2

1000000 1000000 1000000 1000000

x mol mol

   

   − + + ⋅ − −  

  

=   =

⋅    

 − − ⋅ +  

  

Field Code Changed

Field Code Changed

Field Code Changed
raw/exhdry

1.8 47.6 0.050 0.0001 0.0249

1 2 1000000

0.172 0.184

2 47.6 29.3 12.1 8.5 2

1000000 1000000 1000000 1000000

x mol mol

    

    + + − +  

   

=   + =    



⋅ + − + 

 

O2int

0.209820 0.000375 0.206 17.22 1

1000

x mol mol −= =

+

CO2int

0.000375 1000 0.369 17.22 1

1000

x mmol mol ⋅= =

+

H2Ointdry

16.93 17.22 16.93 1

1000

x mmol mol = =

−

CO2dil

0.375 0.371 12.01 1

1000

x mmol mol = =

+

H2Odildry

11.87 =12.01 11.87 1

1000

x mmol mol =

−

COdry

29.0 = 29.3 8.601 1

1000

x mol mol = μ

−

CO2dry

24.98 = 25.2 8.601 1

1000

x mmol mol =

−

NOdry

50.0 = 50.4 8.601 1

1000

x mol mol = μ

−

NO2dry

12.0 = 12.1 8.601 1

1000

x mol mol = μ

−

Field Code Changed

Field Code Changed
THCdry

46 = 47.6 34.16 1

1000

x mol mol = μ

−

α = 1.8 

β = 0.05 

γ = 0.0003

δ = 0.0001 

* * * * * 

(d) * * * 

(1) You may calculate wc as described in this paragraph (d)(1) based on measured fuel 

properties. To do so, you must determine values for α and β in all cases, but you may set 

γ and δ to zero if the default value listed in Table 1 of this section is zero. Calculate wc

using the following equation: 

C

c

C H O S N

1

1

M

w

M M M M M α β γ δ

⋅

=

⋅ + ⋅ + ⋅ + ⋅ + ⋅

Eq. 1065.655-19 

Where: 

wc,c = carbon mass fraction of fuel.

MC = molar mass of carbon. 

α = atomic hydrogen-to-carbon ratio of the mixture of fuel(s) being combusted, weighted 

by molar consumption. 

MH = molar mass of hydrogen. 

β = atomic oxygen-to-carbon ratio of the mixture of fuel(s) being combusted, weighted 

by molar consumption. 

MO = molar mass of oxygen. 

γ = atomic sulfur-to-carbon ratio of the mixture of fuel(s) being combusted, weighted by 

molar consumption. 

MS = molar mass of sulfur. 

δ = atomic nitrogen-to-carbon ratio of the mixture of fuel(s) being combusted, weighted 

by molar consumption. 

MN = molar mass of nitrogen. 

Example:

α = 1.8 

β = 0.05 

γ = 0.0003

δ = 0.0001 
MC = 12.0107 

MH = 1.01 

MO = 15.9994 

MS = 32.065 

MN = 14.0067 

c

1 12.0107

1 12.0107 1.8 1.01 0.05 15.9994 0.0003 32.065 0.0001 14.0067

w

⋅

=

⋅ + ⋅ + ⋅ + ⋅ + ⋅

wc,c = 0.8205

* * * * *

(2) You may use the default values in the following table to determine wc for a given fuel:

Table 1 of §1065.655–Default values of α, β, γ, δ, and wc, for various fuels

Fuel

Atomic hydrogen,

oxygen, sulfur, and 

nitrogen-to-carbon ratios

CHαOβSγNδ

Carbon mass 

fraction, wc

g/g

Gasoline CH1.85O0S0N0 0.866

E10 Gasoline CH1.92O0.03S0N0 0.833

E15 Gasoline CH1.95O0.05S0N0 0.817

E85 Gasoline CH2.73O0.38S0N0 0.576

#1 Diesel CH1.93O0S0N0 0.861

#2 Diesel CH1.80O0S0N0 0.869

Liquefied Petroleum Gas CH2.64O0S0N0 0.819

Natural gas CH3.78 O0.016S0N0 0.747

E100 Ethanol CH3O0.5S0N0 0.521

M100 Methanol CH4O1S0N0 0.375

Residual fuel blends Must be determined by measured fuel properties as 

described in paragraph (d)(1) of this section.

(e) * * * 

(3) Fuel mass flow rate calculation. Based on mfuel  , calculate exh n as follows: 

fuel c H2Oexhdry ( )

exh

c Ccombdry

m w x 1

n

M x

⋅ ⋅ +

=

⋅





Eq. 1065.655-21 

Where: 

exh n = raw exhaust molar flow rate from which you measured emissions. 

mfuel  = fuel flow rate including humidity in intake air. 

Example:

mfuel  = 7.559 g/s 

wC wc = 0.869 g/g 

MC = 12.0107 g/mol 
xCcombdry = 99.87 mmol/mol = 0.09987 mol/mol 

xH20exhdry = 107.64 mmol/mol = 0.10764 mol/mol 

( )

exh

7.559 0.869 1 0.10764

12.0107 0.09987

n

⋅ ⋅ +

=

⋅



exh n = 6.066 mol/s 

(f) Calculated raw exhaust molar flow rate from measured intake air molar flow rate, 

dilute exhaust molar flow rate, and dilute chemical balance. You may calculate the raw 

exhaust molar flow rate from the engine's tailpipe, nexh  , based on the measured intake air 

molar flow rate, int n , the measured dilute exhaust molar flow rate, dexh n , and the values 

calculated using the chemical balance in paragraph (c) of this section. Note that the 

chemical balance must be based on dilute exhaust gas concentrations. For continuousflow calculations, solve for the chemical balance in paragraph (c) of this section at the 

same frequency that you update and record nint  and ndexh  . This calculated raw exhaust 

molar flow rate nexh  may be used for the PM dilution ratio verification in §1065.546; the 

calculation of dilution air molar flow rate in the background correction in §1065.667; and 

the calculation of mass of emissions in §1065.650(c) for species that are measured in the 

raw exhaust. 

(1) Crankcase flow rate. If engines are not subject to crankcase controls under the 

standard-setting part, you may correct the calculatedcalculate raw exhaust flow using 

oneas described in paragraph (e)(1) of the following:this section.

(i) You may measure flow rate through the crankcase vent and subtract it from the 

calculated exhaust flow.

(ii) You may estimate flow rate through the crankcase vent by engineering analysis as 

long as the uncertainty in your calculation does not adversely affect your ability to show 

that your engines comply with applicable emission standards.

(iii) You may assume your crankcase vent flow rate is zero.

(2) Dilute exhaust and intake air molar flow rate calculation. Based on dexh n and int n

Calculate exh n as follows: 

n x x x n n    exh raw/exhdry int/exhdry H2Oexh dexh int = − ⋅ − ⋅ + ( ) (1 )

Eq. 1065.655-22 

Where:

n

exh = raw exhaust molar flow rate from the engine's tailpipe.

n

int = intake air molar flow rate.

Example:

int n = 7.930 mol/s

raw/exhdry x = 0.1544 mol/mol

.0 1451mol/mol xint/exhdry =

H2Oexh x = = 32.46 mmol/mol 0.03246 mol/mol

dexh n = 49.02 mol/s
n

exh = − ⋅ − ⋅ + = + = (0.1544 0.1451 1 0.03246 49.02 7.930 0.4411 7.93 ) ( ) 0 8.371 mol/s

* * * * * 

79. Section 1065.659 is amended by revising paragraphs (a), (b), and (c) to read as 

follows: 

§1065.659 Removed water correction. 

(a) If you remove water upstream of a concentration measurement, x, or upstream of a 

flow measurement, n, correct for the removed water. Perform this correction based on 

the amount of water at the concentration measurement, xH2O[emission]meas, and at the flow 

meter, xH2Oexh, whose flow is used to determine the mass emission rate or concentration’s 

total mass over a test interval. 

(b) When usingForFor continuous analyzers downstream of a sample dryer for transient 

and ramped-modal cyclestesting, you must apply this correction on a for removed water 

using signals from other continuous basis over the test interval, even if you use one of the 

options in §1065.145(e)(2) that results in a constant value for xH2O[emission]meas because 

xH2Oexh varies over the test intervalanalyzers. When usingForinterval. For batch 

analyzers, determine downstream of a sample dryer, you must correct for removed water 

by using signals either from other batch analyzers or from the flow-weighted average 

based on the concentrations from continuous xH2Oexh values determined as described in 

paragraph (c) of this section. For batch analyzers, you may determine the flow-weighted 

average xH2Oexh based on a single value of xH2Oexh determined as described in paragraphs 

(c)(2) and (3) of this section, using flow-weighted average or batch concentration 

inputsanalyzersinputs.

(b) Downstream of where you removed water, you may(b) Determine the amount of 

water remaining downstream of a sample dryer and at the concentration measurement 

using one of the methods described in §1065.145(e)(2). If you use a sample driyer 

upstream of an analyzer and if the calculated amount of water remaining downstream of 

the sample dryer and at the concentration measurement, xH2O[emission]meas, is higher than the 

amount of water at the flow meter, xH2Oexh, set xH2O[emission]meas equal to xH2Oexh. If you use 

a sample driyer upstream of storage media, you must be able to demonstrate that the 

sample driyer is removing water continuously (i.e.., xH2Oexh is higher than xH2O[emission]meas)

throughout the test interval.by any of the following:).

(1) Measure the dewpoint and absolute pressure downstream of the water removal 

location and calculate the amount of water remaining as described in §1065.645.

(2) When saturated water vapor conditions exist at a given location, you may use the 

measured temperature at that location as the dewpoint for the downstream flow. If we 

ask, you must demonstrate how you know that saturated water vapor conditions exist. 

Use good engineering judgment to measure the temperature at the appropriate location to 

accurately reflect the dewpoint of the flow. Note that if you use this option and the water 

correction in paragraph (d) of this section results in a corrected value that is greater than 

the measured value, your saturation assumption is invalid and you must determine the 

water content according to paragraph (b)(1) of this section.

(3) You may also use a nominal value of absolute pressure based on an alarm set point, a 

pressure regulator set point, or good engineering judgment.

(4) Set xH2O[emission]meas equal to that of the measured upstream humidity condition if it is 

lower than the dryer saturation conditions.
(c) For a corresponding concentration or flow measurement where you did not remove 

water, you may set xH2O[emission]meas equal to xH2Oexh. Yyou may determine the amount of 

initial water at the flow meter, xH2Oexh, byusing any of the following methods: 

(1) Measure the dewpoint and absolute pressure and calculate the amount of water as 

described in §1065.645.Use any of the techniques described in paragraph (b) of this 

section.

(2) If the measurement comes from raw exhaust, you may determine the amount of water 

based on intake-air humidity, plus a chemical balance of fuel, intake air, and exhaust as 

described in§1065.655. 

(3) If the measurement comes from diluted exhaust, you may determine the amount of 

water based on intake-air humidity, dilution air humidity, and a chemical balance of fuel, 

intake air, and exhaust as described in §1065.655. 

(d) * * * 

80. Section 1065.660 is amended by revising paragraphs all paragraphs to read as 

follows: 

§1065.660 THC, NMHC, and CH4 determination. 

(a) THC determination and initial THC/CH4 initial contamination corrections. (1) If we 

require you to determine THC emissions, calculate xTHC[THC-FID]cor using the initial THC 

contamination concentration xTHC[THC-FID]init from §1065.520 as follows: 

xTHC[THC-FID]cor = xTHC[THC-FID]uncor – xTHC[THC-FID]init

Eq. 1065.660-1 

Example:

xTHCuncor = 150.3 μmol/mol 

xTHCinit = 1.1 μmol/mol 

xTHCcor = 150.3 – 1.1 

xTHCcor = 149.2 μmol/mol 

(2) For the NMHC determination described in paragraph (b) of this section, correct 

xTHC[THC-FID] for initial THC contamination using Eq. 1065.660-1. You may correct

xTHC[NMC-FID] for initial contamination of the CH4 sample train using Eq. 1065.660-1, 

substituting in CH4 concentrations for THC. 

(3) For the CH4 determination described in paragraph (c) of this section, you may correct

xTHC[NMC-FID] for initial THC contamination of the CH4 sample train using Eq. 1065.660-

1, substituting in CH4 concentrations for THC. 

(b) NMHC determination. Use one of the following to determine NMHC concentration, 

xNMHC: 

(1) If you do not measure CH4, you may determine omit the calculation of NMHC 

concentrations and calculate the mass of NMHC as described in §1065.650(c)(15)(vi5). 

(2) For nonmethane cutters, calculate xNMHC using the nonmethane cutter’s penetration 

fractions (PF) of CH4 and the response factor penetration fraction (RFPF) of C2H6 from 

§1065.365, the response factor (RF) of the THC FID to CH4 from §1065.360, and using 

the initial THC contamination and dry-to-wet corrected THC concentration xTHC[THCFID]cor as determined in paragraph (a) of this section, and the dry-to-wet corrected CH4

concentration xTHC[NMC-FID]cor optionally corrected for initial THC contamination as 

determined in paragraph (a) of this section. 
(i) Use the following equation for penetration fractions determined using an NMC 

configuration as outlined in §1065.365(d): 

THC[THC-FID]cor THC[NMC-FID]cor CH4[THC-FID]

NMHC

C2H6[NMC-FID] CH4[THC-FID] 1

x x RF

x

RFPF RF

− ⋅

=

− ⋅

Eq. 1065.660-2 

Where: 

xNMHC = concentration of NMHC. 

xTHC[THC-FID]cor = concentration of THC, initial THC contamination and dry-to-wet 

corrected, as measured by the THC FID during sampling while bypassing the NMC. 

xTHC[NMC-FID]cor = concentration of THC, initial THC contamination (optional) and dry-towet corrected, as measured by the NMC FID during sampling through the NMC. 

RFCH4[THC-FID] = response factor of THC FID to CH4, according to §1065.360(d). 

RFPFC2H6[NMC-FID] = nonmethane cutter combined ethane response factor and penetration 

fraction, according to §1065.365(d). 

Example:

xTHC[THC-FID]cor = 150.3 μmol/mol 

xTHC[NMC-FID]cor = 20.5 μmol/mol 

RFPFC2H6[NMC-FID] = 0.019 

RFCH4[THC-FID] = 1.05 

NMHC

150.3 20.5 1.05

1 0.019 1.05

x

− ⋅

=

− ⋅

xNMHC = 131.4 μmol/mol 

(ii) For penetration fractions determined using an NMC configuration as outlined in 

section §1065.365(e), use the following equation: 

THC[THC-FID]cor CH4[NMC-FID] THC[NMC-FID]cor

NMHC

CH4[NMC-FID] C2H6[NMC-FID]

x PF x

x

PF PF

⋅ −

=

−

Eq. 1065.660-3 

Where: 

xNMHC = concentration of NMHC. 

xTHC[THC-FID]cor = concentration of THC, initial THC contamination and dry-to-wet 

corrected, as measured by the THC FID during sampling while bypassing the NMC. 

PFCH4[NMC-FID] = nonmethane cutter CH4 penetration fraction, according to §1065.365(e). 

xTHC[NMC-FID]cor = concentration of THC, initial THC contamination (optional) and dry-towet corrected, as measured by the THC FID during sampling through the NMC. 

PFC2H6[NMC-FID] = nonmethane cutter ethane penetration fraction, according to 

§1065.365(e). 

Example: 

xTHC[THC-FID]cor = 150.3 μmol/mol 

PFCH4[NMC-FID] = 0.990 

xTHC[NMC-FID]cor = 20.5 μmol/mol 

PFC2H6[NMC-FID] = 0.020 

Field Code Changed

Field Code Changed

Field Code Changed
NMHC

150.3 0.990 20.5

0.990 0.020

x

⋅ −

=

−

NMHC

150.3 0.990 20.5

0.990 0.020

x

⋅ −

=

−

xNMHC = 132.3 μmol/mol 

(iii) For penetration fractions determined using an NMC configuration as outlined in 

section §1065.365(f), use the following equation: 

THC[THC-FID]cor CH4[NMC-FID] THC[NMC-FID]cor CH4[THC-FID]

NMHC

CH4[NMC-FID] C2H6[NMC-FID] CH4[THC-FID]

x PF x RF

x

PF RFPF RF

⋅ − ⋅

=

− ⋅

THC[THC-FID]cor CH4[NMC-FID] THC[NMC-FID]cor CH4[THC-FID]

NMHC

CH4[NMC-FID] C2H6[NMC-FID] CH4[THC-FID]

x PF x RF

x

PF RFPF RF

⋅ − ⋅

=

− ⋅

Eq. 1065.660-4 

Where: 

xNMHC = concentration of NMHC. 

xTHC[THC-FID]cor = concentration of THC, initial THC contamination and dry-to-wet 

corrected, as measured by the THC FID during sampling while bypassing the NMC. 

PFCH4[NMC-FID] = nonmethane cutter CH4 penetration fraction, according to §1065.365(f). 

xTHC[NMC-FID]cor = concentration of THC, initial THC contamination (optional) and dry-towet corrected, as measured by the THC FID during sampling through the NMC. 

RFPFC2H6[NMC-FID] = nonmethane cutter CH4 combined ethane response factor and 

penetration fraction, according to §1065.365(f). 

RFCH4[THC-FID] = response factor of THC FID to CH4, according to §1065.360(d). 

Example: 

xTHC[THC-FID]cor = 150.3 μmol/mol 

PFCH4[NMC-FID] = 0.990 

xTHC[NMC-FID]cor = 20.5 μmol/mol 

RFPFC2H6[NMC-FID] = 0.019 

RFCH4[THC-FID] = 0.980 

NMHC

150.3 0.990 20.5 0.980

0.990 0.019 0.980

x

⋅ − ⋅

=

− ⋅

xNMHC = 132.5 μmol/mol 

(3) For a GC-FIDgas chromatographFID, calculate xNMHC using the THC analyzer’s 

response factor (RF) for CH4, from §1065.360, and the initial THC contamination and 

dry-to-wet corrected initial THC concentration xTHC[THC-FID]cor as determined in paragraph 

(a) of this section as follows: 

NMHC THC[THC-FID]cor CH4[THC-FID] CH4 x x RF x = − ⋅

Eq. 1065.660-5 

Where: 

xNMHC = concentration of NMHC. 

xTHC[THC-FID]cor = concentration of THC, initial THC contamination and dry-to-wet 

corrected, as measured by the THC FID. 

Field Code Changed
xCH4= concentration of CH4, HC contamination (optional) and dry-to-wet corrected, as 

measured by the GC-gas chromatograph FID. 

RFCH4[THC-FID] = response factor of THC-FID to CH4. 

Example:

xTHC[THC-FID[cor = 145.6 μmol/mol 

RFCH4[THC-FID] = 0.970 

xCH4 = 18.9 μmol/mol 

xNMHC = 145.6 – 0.970 · 18.9 

xNMHC = 127.3 μmol/mol 

(c) CH4 determination. Use one of the following methods to determine CH4

concentration, xCH4: 

(1) For nonmethane cutters, calculate xCH4 using the nonmethane cutter’s penetration 

fractions (PF) of CH4 and the response factor penetration fraction (RFPF) of C2H6 from 

§1065.365, the response factor (RF) of the THC FID to CH4 from §1065.360, the initial 

THC contamination and dry-to-wet corrected THC concentration xTHC[THC-FID]cor as 

determined in paragraph (a) of this section, and using the dry-to-wet corrected CH4

concentration xTHC[NMC-FID]cor optionally corrected for initial THC contamination as 

determined in paragraph (a) of this section and optionally using the CH4 contamination 

correction under paragraph (a) of this section.. 

(i) Use the following equation for penetration fractions determined using an NMC 

configuration as outlined in §1065.365(d): 

THC[NMC-FID]cor THC[THC-FID]cor C2H6[NMC-FID]

CH4

C2H6[NMC-FID] CH4[THC-FID] 1

x x RFPF

x

RFPF RF

− ⋅

=

− ⋅

Eq. 1065.660-6 

Where: 

xCH4 = concentration of CH4. 

xTHC[NMC-FID]cor = concentration of THC, initial THC contamination (optional) and dry-towet corrected, as measured by the NMC FID during sampling through the NMC. 

xTHC[THC-FID]cor = concentration of THC, initial THC contamination and dry-to-wet 

corrected, as measured by the THC FID during sampling while bypassing the NMC. 

RFPFC2H6[NMC-FID] = the combined ethane response factor and penetration fraction of the 

nonmethane cutter, according to §1065.365(d). 

RFCH4[THC-FID] = response factor of THC FID to CH4, according to §1065.360(d). 

Example:

xTHC[NMC-FID]cor = 10.4 μmol/mol 

xTHC[THC-FID]cor = 150.3 μmol/mol 

RFPFC2H6[NMC-FID] = 0.019 

RFCH4[THC-FID] = 1.05 

CH4

10.4 150.3 0.019

1 0.019 1.05

x

− ⋅

=

− ⋅

xCH4 = 7.69 μmol/mol 

Field Code Changed

Field Code Changed
(ii) For penetration fractions determined using an NMC configuration as outlined in 

§1065.365(e), use the following equation: 

( )

THC[NMC-FID]cor THC[THC-FID]cor C2H6[NMC-FID]

CH4

CH4[THC-FID] CH4[NMC-FID] C2H6[NMC-FID]

x x PF

x

RF PF PF

− ⋅

=

⋅ −

Eq. 1065.660-7 

Where: 

xCH4 = concentration of CH4. 

xTHC[NMC-FID]cor = concentration of THC, initial THC contamination (optional) and dry-towet corrected, as measured by the NMC FID during sampling through the NMC. 

xTHC[THC-FID]cor = concentration of THC, initial THC contamination and dry-to-wet 

corrected, as measured by the THC FID during sampling while bypassing the NMC. 

PFC2H6[NMC-FID] = nonmethane cutter ethane penetration fraction, according to 

§1065.365(e). 

RFCH4[THC-FID] = response factor of THC FID to CH4, according to §1065.360(d). 

PFCH4[NMC-FID] = nonmethane cutter CH4 penetration fraction, according to §1065.365(e). 

Example: 

xTHC[NMC-FID]cor = 10.4 μmol/mol 

xTHC[THC-FID]cor = 150.3 μmol/mol 

PFC2H6[NMC-FID] = 0.020 

RFCH4[THC-FID] = 1.05 

PFCH4[NMC-FID] = 0.990 

( ) CH4

10.4 150.3 0.020

1.05 0.990 0.020

x

− ⋅

=

⋅ −

xCH4 = 7.25 μmol/mol 

(iii) For penetration fractions determined using an NMC configuration as outlined in 

§1065.365(f), use the following equation: 

THC[NMC-FID]cor THC[THC-FID]cor C2H6[NMC-FID]

CH4

CH4[NMC-FID] C2H6[NMC-FID] CH4[THC-FID]

x x RFPF

x

PF RFPF RF

− ⋅

=

− ⋅

Eq. 1065.660-8 

Where: 

xCH4 = concentration of CH4. 

xTHC[NMC-FID]cor = concentration of THC, initial THC contamination (optional) and dry-towet corrected, as measured by the NMC FID during sampling through the NMC. 

xTHC[THC-FID]cor = concentration of THC, initial THC contamination and dry-to-wet 

corrected, as measured by the THC FID during sampling while bypassing the NMC. 

RFPFC2H6[NMC-FID] = the combined ethane response factor and penetration fraction of the 

nonmethane cutter, according to §1065.365(f). 

PFCH4[NMC-FID] = nonmethane cutter CH4 penetration fraction, according to §1065.365(f). 

RFCH4[THC-FID] = response factor of THC FID to CH4, according to §1065.360(d). 

Example: 

xTHC[NMC-FID]cor = 10.4 μmol/mol 

xTHC[THC-FID]cor = 150.3 μmol/mol 

Field Code Changed

Field Code Changed

Field Code Changed
RFPFC2H6[NMC-FID] = 0.019 

PFCH4[NMC-FID] = 0.990 

RFCH4[THC-FID] = 1.05 

CH4

10.4 150.3 0.019

0.990 0.019 1.05

x

− ⋅

=

− ⋅

xCH4 = 7.78 μmol/mol 

(2) For a gas chromatographGCGC-FID, xCH4 is the actual dry-to-wet corrected CH4

concentration as measured by the analyzer. 

* * * * *

* * * * *

81. Section 1065.667 is amended by adding a new paragraph (f) and revising paragraphs 

(a), (b), (c), (d), and (e) to read as follows: 

§1065.667 Dilution air background emission correction.

(a) To determine the mass of background emissions to subtract from a diluted exhaust 

sample, first determine the total flow of dilution air, ndil, over the test interval. This may 

be a measured quantity or a calculated quantity calculated from the diluted exhaust flow 

and the flow-weighted mean fraction of dilution air in diluted exhaust, dil/exh x

.. Multiply 

the total flow of dilution air by the mean mole fraction (i.e., concentration) of a 

background emission. This may be a time-weighted mean or a flow-weighted mean 

(e.g., a proportionally sampled background). Finally, multiply by the molar mass, M, of 

the associated gaseous emissions speciesemission constituent. The product of ndil and 

the mean molar concentration of a background emission and its molar mass, M, is the 

total amount of a background emission, m. If this is a molar quantity, convert it to a 

mass by multiplying it by its molar mass, M. The result is the mass of the background 

emission, m.background emission mass, m. In the case of PM, where the mean PM 

concentration is already in units of mass per mole of sample, MPM , multiply it by the 

total amount of dilution air flow, and the result is the total background mass of PM, 

mPM. Subtract total background masses from total mass to correct for background 

emissions. 

(b) You may determine the total flow of dilution air by a direct flow measurement. In 

this case, calculate the total mass of background as described in §1065.650(c), using the 

dilution air flow, ndil. Subtract the background mass from the total mass. Use the result 

in brake-specific emission calculations.

(c) You may determine the total flow of dilution air by subtracting the calculated raw 

exhaust molar flow as described in §1065.655(f) from the measured dilute exhaust flow. 

This may be done by totaling continuous calculations or by using batch results. 

(cdd) You may determine the total flow of dilution air from the total flow ofmeasured 

dilutedmeasured dilute exhaust flow and a chemical balance of the fuel, intake air, and 

dilute exhaust as described in §1065.655. For this option, the molar flow of dilution air 

is calculated by multiplying the dilute exhaust flow by the mole fraction of dilution gas 

to dilute exhaust, dil/exh x , from the dilute chemical balance. This may be done by totaling 

continuous calculations or by using batch results. In this case, calculate the total mass 

Field Code Changed
of background as described in §1065.650(c), usingFor For example, to use batch 

results, the total flow of dilution air is calculated by multiplying the total flow of diluted 

exhaust, ndexh, then multiply this result by the flow-weighted mean mole fraction of 

dilution air in diluted exhaust, dil/exh x . Calculate dil/exh x using flow-weighted mean 

concentrations of emissions in the chemical balance, as described in §1065.655. The 

chemical balance in §1065.655 You may assumes that your engine operates 

stoichiometrically, even if it is a lean-burn engine, such as a compression-ignition 

engine. Note that for lean-burn engines this assumption could result in an error in 

emission calculations. This error could occur because the chemical balances in 

§1065.655 correct treats excess air passing through a lean-burn engine as if it was 

dilution air. If an emission concentration expected at the standard is about 100 times its 

dilution air background concentration, this error is negligible. However, if an emission 

concentration expected at the standard is similar to its background concentration, this 

error could be significant. If this error might affect your ability to show that your 

engines comply with applicable standards, we recommend that you either determine the 

total flow of dilution air using one of the more accurate methods in paragraphs (b) or (c) 

of this section, or remove background emissions from dilution air by HEPA filtration, 

chemical adsorption, or catalytic scrubbing. You might also consider using a partialflow dilution technique such as a bag mini-diluter, which uses purified air as the dilution 

air. 

(dee) The following is an example of using the flow-weighted mean fraction of dilution 

air in diluted exhaust, dil/exh x , and the total mass of background emissions calculated 

using the total flow of diluted exhaust, ndexh, as described in §1065.650(c): 

m x m bkgnd dil/exh bkgnddexh = ⋅

Eq. 1065.667-1 

m M x n bkgnddexh bkgnd dexh = ⋅ ⋅

Eq. 1065.667-2 

Example:

MNOx = 46.0055 g/mol 

bkgnd x = 0.05 μmol/mol = 0.05⋅10-6 mol/mol

ndexh = 23280.5 mol 

dil/exh x = 0.843 mol/mol 

6 mbkgndNOxdexh 46.0055 0.05 10 23280.5 −

= ⋅ ⋅ ⋅

mbkgndNOxdexh = 0.0536 g 

mbkgndNOx = 0.843 · 0.0536 

mbkgndNOx = 0.0452 g 

(eff) The following is an example of using the fraction of dilution air in diluted exhaust, 

xdil/exh, and the mass rate of background emissions calculated using the flow rate of

diluted exhaust, dexh n , as described in §1065.650(c) : 

m x m   bkgnd dil/exh bkgnddexh = ⋅

Eq. 1065.667-3 
m M x n   bkgnddexh bkgnd dexh = ⋅ ⋅

Eq. 1065.667-4 

Example:

MNOx = 46.0055 g/mol 

xbkgnd = 0.05 μmol/mol = 0.05⋅10-6 mol/mol 

dexh n = 23280.5 mol/s 

xdil/exh = 0.843 mol/mol 

6 mbkgndNOxdexh 46.0055 0.05 10 23280.5 −

 = ⋅ ⋅ ⋅

mbkgndNOxdexh  = 0.0536 g/hr 

mbkgndNOx  = 0.843 · 0.0536 

mbkgndNOx  = 0.0452 g/hr 

82. Section 1065.670 is amended by revising the introductory paragraph to read as 

follows: 

§1065.670 NOx intake-air humidity and temperature corrections. 

See the standard-setting part to determine if you may correct NOx emissions for the 

effects of intake-air humidity or temperature. Use the NOx intake-air humidity and 

temperature corrections specified in the standard-setting part instead of the NOx intakeair humidity correction specified in this part 1065. If the standard-setting part does not 

prohibit correcting NOx emissions for intake-air humidity according to this part 1065, 

first apply any NOx corrections for background emissions and water removal from the 

exhaust sample, then correct NOx concentrations for intake-air humidity as described in 

this paragraphsection. See §1065.650(c)(1) for the proper sequence for applying the NOx

intake-air humidity and temperature corrections. You may use a time-weighted mean 

combustion air humidity to calculate this correction if your combustion air humidity 

remains within a tolerance of ±0.0025 mol/mol of the mean value over the test interval. 

For intake-air humidity correction, use one of the following approaches: 

* * * * * 

83. Section 1065.675 is amended by revising paragraph (d) to read as follows: 

§1065.675 CLD quench verification calculations. 

* * * * * 

(d) Calculate quench as follows: 

NOwet

H2Omeas H2Oexp CO2exp NOmeas

NOdry H2Omeas NOact CO2act

1

1 1 100 %

x

x x x x

quench

x x x x

  

  

−  

= − ⋅ + − ⋅ ⋅   

      

 

  

Eq. 1065.675-1 

Where: 

quench = amount of CLD quench. 

xNOdry = concentration of NO upstream of a bubbler, according to §1065.370(e)(4). 
xNOwet = measured concentration of NO downstream of a bubbler, according to 

§1065.370(e)(9). 

xH2Oexp = maximum expected mole fraction of water during emission testing, according to 

paragraph (b) of this section. 

xH2Omeas = measured mole fraction of water during the quench verification, according to 

§1065.370(e)(7). 

xNOmeas = measured concentration of NO when NO span gas is blended with CO2 span 

gas, according to §1065.370(d)(10). 

xNOact = actual concentration of NO when NO span gas is blended with CO2 span gas, 

according to §1065.370(d)(11) and calculated according to Equation 1065.675-2. 

xCO2exp = maximum expected concentration of CO2 during emission testing, according to 

paragraph (c) of this section. 

xCO2act = actual concentration of CO2 when NO span gas is blended with CO2 span gas, 

according to §1065.370(d)(9). 

CO2act

NOact NOspan

CO2span

1

x

x x

x

 

= − ⋅  

 

Eq. 1065.675-2 

Where: 

xNOspan = the NO span gas concentration input to the gas divider, according to 

§1065.370(d)(5). 

xCO2span = the CO2 span gas concentration input to the gas divider, according to 

§1065.370(d)(4). 

Example:

xNOdry = 1800.0 μmol/mol 

xNOwet = 17291739.6 μmol/mol 

xH2Oexp = 0.030 mol/mol 

xH2Omeas = 0.030 mol/mol 

xNOmeas = 14951515.2 μmol/mol 

xNOspan = 3001.6 μmol/mol 

xCO2exp = 3.2 % 

xCO2span = 6.00 1 % 

xCO2act = 2.98 % 

NOact

2.98 1 3001.6 1535.24459 μmol/mol

6.1

x

 

= − ⋅ =    

1739.6

1 0.030 0.030 1515.2 3.2 1 1 100 %

1800.0 0.030 1535.24459 2.98

quench

  

  

−  

= − ⋅ + − ⋅ ⋅     

    

 

  

quench = (–0.00939 003660036655 – 0.0110901398 014020171)⋅100 % = –

2.00481.7649 % = -21.7685671 % 

Subpart H—[Amended] 

Field Code Changed

Field Code Changed
84. Section 1065.750 is amended by revising paragraphs (a)(3) and (a)(4) to read as 

follows: 

§1065.750 Analytical Gases. 

* * * * * 

(a) * * * 

(3) Use the following gas mixtures, with gases traceable within ±1.0 % of the NISTaccepted value or other gas standards we approve: 

* * * * * 

(4) You may use gases for species other than those listed in paragraph (a)(3) of this 

section (such as methanol in air, which you may use to determine response factors), as 

long as they are traceable to within ±3.0 % of the NIST-accepted value or other similar 

standards we approve, and meet the stability requirements of paragraph (b) of this 

section. 

* * * * * 

85. Section 1065.790 is amended by revising paragraph (a) to read as follows: 

§1065.790 Mass standards. 

(a) PM balance calibration weights. Use PM balance calibration weights that are certified 

as NIST-traceable within 0.1 % uncertainty. Calibration weights may be certified by any 

calibration lab that maintains NIST-traceability. Make sure your lowest highest 

calibration weight has no greater than ten times the mass of an unused PM-sample 

medium. 

Subpart J—[Amended] 

86. Section 1065.915 is amended by revising Table 1 to read as follows: 

§1065.915 PEMS instruments. 

* * * * * 

(a) * * * 
Table 1 of §1065.915–Recommended minimum PEMS measurement instrument performance 

Measurement Measured quantity symbol Rise time, t10-90, and Fall time, t90-10 Recording update frequency Accuracy

1 Repeatability

1 

Engine speed transducer 

fn 1 s 1 Hz means 

5.0 % of pt. or 

1.0 % of max. 

2.0 % of pt. or 

1.0 % of max. 0.5 

Engine torque estimator, BSFC 

(This is a signal from an engine’s ECM) 

T or BSFC 1 s 1 Hz means 

8.0 % of pt. or 

5 % of max. 

2.0 % of pt. or 

1.0 % of max. 

1.0 

General pressure transducer 

(not a part of another instrument) 

p 5 s 1 Hz 

5.0 % of pt. or 

5.0 % of max. 

2.0 % of pt. or 

0.5 % of max. 

1.0 

Atmospheric pressure meter patmos 50 s 0.1 Hz 250 Pa 200 Pa 

General temperature sensor 

(not a part of another instrument) 

T 5 s 1 Hz 

1.0 % of pt. K or 

5 K 

0.5 % of pt. K or 

2 K 

0.5 

General dewpoint sensor 

Tdew 50 s 0.1 Hz 3 K 1 K 

Exhaust flow meter n 1 s 1 Hz means 

5.0 % of pt. or 

3.0 % of max. 

2.0 % of pt. 2.0 

Dilution air, inlet air, exhaust, and sample 

flow meters 

n 1 s 1 Hz means 2.5 % of pt. or 1.5 % of max. 1.25 % of pt. or 0.75 % of max. 

1.0 

Continuous gas analyzer x 5 s 1 Hz 

4.0 % of pt. or 

4.0 % of meas. 

2.0 % of pt. or 

2.0 % of meas. 

1.0 

Gravimetric PM balance 

mPM N/A N/A See §1065.790 0.5 μg 

Inertial PM balance 

mPM N/A N/A 

4.0 % of pt. or 

4.0 % of meas. 

2.0 % of pt. or 

2.0 % of meas. 

1.0 

a 1Accuracy, repeatability, and noise are all determined with the same collected data, as described in §1065.305, and based on absolute values. “pt.” refers to tflow-weighted mean value expected at the standard; “max.” refers to the peak value expected at the standard over any test interval, not the maximum of the irange; “meas” refers to the actual flow-weighted mean measured over any test interval. 

* * * * * 
87. Section 1065.925 is amended by revising paragraphs (h)(1), (h)(2), and (h)(3) to 

read as follows: 

§1065.925 PEMS preparation for field testing. 

* * * * * 

(h) * * * 

(1) Select the HC analyzers’ rangesanalyzer range for measuring the maximum 

concentration expected at the HC standard. 

(2) Zero the HC analyzers using a zero gas or ambient air introduced at the analyzer port. 

When zeroing the a FIDs, use the FID’s’ burner air that would be used for in-use 

measurements (generally either ambient air or a portable source of burner air). 

(3) Span the HC analyzers using span gas introduced at the analyzer port. When spanning 

the FIDs, use the FIDs’ burner air that would be used in-use (for example, use ambient air 

or a portable source of burner air).

* * * * * 

Subpart K—[Amended] 

88. Section 1065.1001 is amended by revising the introductory text to read as follows: 

§1065.1001 Definitions. 

* * * * * 

 Electric power generation application means an application that requires the 

engine speed to be very precisely controlled for thewhose purpose of generatingis to 

generate a precise frequency of electricity. Note that, which is characterized by an engine 

that controls engine speed very precisely. This would generally not apply to welders or 

portable home generators. 

* * * * * 

 High-idle speed means the engine speed whereat which an engine governor function 

controls engine speed with operator demand at maximum and with zero load applied. 

Note that “Warm high-idle speed” is the high-idle speed of a warmed-up engine. 

High-speed governor means any device, system, or element of design that 

modulates the engine output torque for the purpose of limiting the maximum engine 

speed. 

* * * * * 

 Idle speed means the lowest engine speed whereat which an engine governor 

function controls engine speed with operator demand at minimum and with minimum 

load applied (greater than or equal to zero load), where an engine governor function 

controls engine speed.). For engines without a governor function that controls idle speed, 

idle speed means the manufacturer-declared value for lowest engine speed possible with 

minimum load. Note that warm idle speed This definition does not apply for operation 

designated as “high-idle speed.” “Warm idle speed” is the idle speed of a warmed-up 

engine. 

* * * * * 

Percent (%) means a representation of exactly 0.01 (with infinite precision). 

Note, however, that the precision of calculated values. Numbers expressed as percent is 

determined by standard rules of rounding, as specifiedpercentages in §1065.20. 
Significant digits for the product of % and another value, or the expression of any other 

value this part (such as a percentage, are defined as follows:

(1) tolerance of ±2 %) have infinite precision, so 2 % and 2.000000000 % have 

the same meaning. This means that where we specify some percentage of a total value,

the calculated value has the same number of significant digits as the total value. The 

specified percentage by which the total value is multiplied has infinite precision, so that 2 

% is exactly 0.02. Note that not all displayed or recorded digits are significant. For 

example, 2 % of a span value where the span value is 101.3302 is 2.026604. However, 

where the span value is known to have has limited precision such that only one digit to 

the right of the decimal is significant (i.e., the actual value is 101.3), 2 % of the span 

value is 2.026.

(2) In other cases, determine the number of significant digits using the same method as 

you would use for determining the number of significant digits of any calculated value. 

For example, a calculated value of 0.321, where all three digits are significant, is 

equivalent to 32.1 %.

* * * * * 

Round means to apply the rounding convention specified in §1065.20(e)round 

numbers according to NIST SP 811 (incorporated by reference in §1065.1010), unless 

otherwise specified. 

* * * * * 

89. Section 1065.1005 is amended by revising the introductory text, paragraphs (a), (e), 

(f)(2), and (g) to read as follows: 

§1065.1005 Symbols, abbreviations, acronyms, and units of measure. 

The procedures in this part generally follow the International System of Units (SI), as 

detailed in NIST Special Publication 811, “Guide for the Use of the International System 

of Units (SI),” which we incorporate by reference in §1065.1010. See §1065.2520 for 

specific provisions related to these conventions. This section summarizes the way we use 

symbols, units of measure, and other abbreviations.

(a) Symbols for quantities. This part uses the following symbols and units of measure for 

various quantities: 

Symbol Quantity Unit Unit symbol Units in terms of SI 

base SI uUnitsunits

% percent 0.01 % 10-2

α atomic hydrogen to carbon ratio mole per mole mol/mol 1 

A area square meter m2 m2

A0 intercept of least squares regression 

A1 slope of least squares regression 

β ratio of diameters meter per meter m/m 1 

β atomic oxygen to carbon ratio mole per mole mol/mol 1 

C

#

number of carbon atoms in a molecule

d Diameter meter m m 

DR dilution ratio mole per mol mol/mol 1 

ε

error between a quantity and its 

reference 

e

brake-specific basisemission or fuel 

consumption gram per kilowatt hour g/(kW·hr) g·3.6-1

·106·m

-2

·kg·s

2

F F-test statistic

f frequency hertz Hz s

-1

fn angular speed rotational frequency revolutions per minute revr/min 2·πpiπ·60-1· m·m-1·s-
(shaft) 1

γ ratio of specific heats 

(joule per kilogram 

kelvin) per (joule per 

kilogram kelvin) 

(J/(kg·K))/(J/(kg·K)) 1 

K correction factor 1 

l length meter m m 

μ viscosity, dynamic pascal second Pa·s m-1

·kg·s

-1

M molar mass1 gram per mole g/mol 10-3·kg·mol-1

m mass kilogram kg kg 

m mass rate kilogram per second kg/s kg·s

-1

ν viscosity, kinematic meter squared per 

second m

2

/s m2·s

-1

N total number in series 

n amount of substance mole mol mol 

n amount of substance rate mole per second mol/s mol·s

-1

P power kilowatt kW 103·m

2

·kg·s

-3

PF penetration fraction 

p pressure pascal Pa m-1·kg·s

-2

ρ mass density kilogram per cubic 

meter 

kg/m3 kg·m

-3

r ratio of pressures pascal per pascal Pa/Pa 1 

R

2

 coefficient of determination 

Ra average surface roughness micrometer μm m1010-6 m 

Re# Reynolds number

RF response factor

RH % relative humidity 0.01 % 10-2

σ non-biased standard deviation 

S Sutherland constant kelvin K K 

SEE standard estimate of error 

T absolute temperature kelvin K K 

T Celsius temperature degree Celsius °C K-273.15 

T torque (moment of force) newton meter N·m m2·kg·s

-2

t time second s s 

∆t time interval, period, 1/frequency second s s 

V volume cubic meter m3 m3

V volume rate cubic meter per second m3

/s m3·s

-1

W work kilowatt hour kW·hr 3.6·10-6·m

2

·kg·s

-2

wc carbon mass fraction gram per gram g/g 1 

x amount of substance mole fraction 2 mole per mole mol/mol 1 

x flow-weighted mean concentration mole per mole mol/mol 1 

y generic variable 

1

 See paragraph (f)(2) of this section for the values to use for molar masses. Note that in the cases of NOx and HC, the 

regulations specify effective molar masses based on assumed speciation rather than actual speciation. 

2 Note that mole fractions for THC, THCE, NMHC, NMHCE, and NOTHC are expressed on a C1 equivalent basis. 

* * * * * 

(e) Subscripts. This part uses the following subscripts to define a quantity: 

Subscript Quantity 

abs absolute quantity 

act actual condition 

air air, dry 

atmos atmospheric 

cal calibration quantity 

CFV critical flow venturi 

cor corrected quantity 

dil dilution air 

dexh diluted exhaust 

exh raw exhaust 
exp expected quantity 

hi,idle condition at high-idle 

i an individual of a series 

idle condition at idle 

in quantity in 

init initial quantity, typically before an emission test

j an individual of a series

max 

the maximum (i.e., peak) value expected at the standard over a 

test interval; not the maximum of an instrument range 

meas measured quantity 

out quantity out

part partial quantity 

PDP positive-displacement pump

ref reference quantity 

rev revolution 

sat saturated condition 

slip PDP slip 

span span quantity 

SSV subsonic venturi 

std standard condition 

test test quantity 

test,alt alternate test quantity 

uncor uncorrected quantity 

zero zero quantity 

(f) * * * 

(2) This part uses the following molar masses or effective molar masses of chemical 

species:

Symbol Quantity g/mol 

(10-3.kg.mol-1) 

Mair molar mass of dry air 1air128.96559 

MAr molar mass of argon 39.948 

MC molar mass of carbon 12.010716.0425010

7

MC3H8 molar mass of propane 44.09562 

MCH4 molar mass of methane 16.043 

MCO molar mass of carbon monoxide 28.0101 

MCO2 molar mass of carbon dioxide 44.0095 

MH molar mass of atomic hydrogen 1.00794 

MH2 molar mass of molecular hydrogen 2.01588 

MH2O molar mass of water 18.01528 

MHe molar mass of helium 4.002602 

MN molar mass of atomic nitrogen 14.0067 

MN2 molar mass of molecular nitrogen 28.0134 

MNMHC effective molar mass of nonmethane hydrocarbon2 13.875389 

MNMHCE effective molar mass of nonmethane equivalent hydrocarbon213.875389

MNOx effective molar mass of oxides of nitrogen3 46.0055 

MN2O effective molar mass of nitrous oxide 44.0128

MO molar mass of atomic oxygen 15.9994 

MO2 molar mass of molecular oxygen 31.9988 

MS molar mass of sulfur 32.065 

MTHC effective molar mass of total hydrocarbon2 13.875389 

MTHCE effective molar mass of total hydrocarbon equivalent2 13.875389 

1

See paragraph (f)(1) of this section for the composition of dry air. 

2The effective molar masses of THC, THCE, NMHC, and NMHCE are defined by an atomic 

hydrogen-to-carbon ratio, α, of 1.85. 

3The effective molar mass of NOx is defined by the molar mass of nitrogen dioxide, NO2. 
(g) Other acronyms and abbreviations. This part uses the following additional 

abbreviations and acronyms: 

ASTM American Society for Testing and Materials 

BMD bag mini-diluter 

BSFC brake-specific fuel consumption

CARB California Air Resources Board

CFR Code of Federal Regulations 

CFV critical-flow venturi

CI compression-ignition 

CITT Curb Idle Transmission Torque 

CLD chemiluminescent detector 

CVS constant-volume sampler 

DF deterioration factor 

ECM electronic control module 

EFC electronic flow control 

EGR exhaust gas recirculation 

EPA Environmental Protection Agency 

FEL Family Emission Limit 

FID flame-ionization detector 

GC gas chromatograph 

GC-ECD gas chromatograph with an electron-capture detector 

GC-FID gas chromatograph with a flame ionization detector

IBP initial boiling point

ISO International Organization for Standardization

LPG liquefied petroleum gas

NDIR nondispersive infrared

NDUV nondispersive ultraviolet 

NIST National Institute for Standards and Technology 

NMC nonmethane cutter

PDP positive-displacement pump 

PEMS portable emission measurement system 

PFD partial-flow dilution 

PMP Polymethylpentene 

pt. a single point at the mean value expected at the standard. 

PTFE polytetrafluoroethylene (commonly known as TeflonTM) 

RE rounding error 

RESS rechargeable energy storage system

RMC ramped-modal cycle 

RMS root-mean square 

RTD resistive temperature detector 

SSV subsonic venturi

SI spark-ignition 

UCL upper confidence limit

UFM ultrasonic flow meter 

U.S.C. United States Code 

* * * * *

* * * * *

90. Section 1065.1010 is amended by revising paragraph (c) to read as follows: 

§1065.1010 Reference materials. 

* * * * *
Documents listed in this section have been incorporated by reference into this part. The 

Director of the Federal Register approved the incorporation by reference as prescribed in 

5 U.S.C. 552(a) and 1 CFR part 51. Anyone may inspect copies at the U.S. EPA, Air and 

Radiation Docket and Information Center, 1301 Constitution Ave., NW., Room B102, 

EPA West Building, Washington, DC 20460 or at the National Archives and Records 

Administration (NARA). For information on the availability of this material at NARA, 

call 202-741-6030, or go to: 

http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

(a) ASTM material. Table 1 of this section lists material from the American Society for 

Testing and Materials that we have incorporated by reference. The first column lists the 

number and name of the material. The second column lists the sections of this part where 

we reference it. Anyone may purchase copies of these materials from the American 

Society for Testing and Materials, 100 Barr Harbor Dr., P.O. Box C700, West 

Conshohocken, PA 19428 or www.astm.com. Table 1 follows:

Table 1 of §1065.1010–ASTM materials

Document number and name Part 1065 

reference

ASTM D86-07a, Standard Test Method for Distillation of Petroleum Products at Atmospheric Pressure 1065.703, 

1065.710

ASTM D93-07, Standard Test Methods for Flash Point by Pensky-Martens Closed Cup Tester 1065.703

ASTM D445-06, Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and the 

Calculation of Dynamic Viscosity) 1065.703

ASTM D613-05, Standard Test Method for Cetane Number of Diesel Fuel Oil 1065.703

ASTM D910-07, Standard Specification for Aviation Gasolines 1065.701

ASTM D975-07b, Standard Specification for Diesel Fuel Oils 1065.701

ASTM D1267-02 (Reapproved 2007), Standard Test Method for Gage Vapor Pressure of Liquefied Petroleum 

(LP) Gases (LP-Gas Method) 1065.720

ASTM D1319-03, Standard Test Method for Hydrocarbon Types in Liquid Petroleum Products by 

Fluorescent Indicator Adsorption 1065.710

ASTM D1655-07e01, Standard Specification for Aviation Turbine Fuels 1065.701

ASTM D1837-02a (Reapproved 2007), Standard Test Method for Volatility of Liquefied Petroleum (LP) 

Gases 1065.720

ASTM D1838-07, Standard Test Method for Copper Strip Corrosion by Liquefied Petroleum (LP) Gases 1065.720

ASTM D1945-03, Standard Test Method for Analysis of Natural Gas by Gas Chromatography 1065.715

ASTM D2158-05, Standard Test Method for Residues in Liquefied Petroleum (LP) Gases 1065.720

ASTM D2163-05, Standard Test Method for Analysis of Liquefied Petroleum (LP) Gases and Propene 

Concentrates by Gas Chromatography 1065.720

ASTM D2598-02 (Reapproved 2007), Standard Practice for Calculation of Certain Physical Properties of 

Liquefied Petroleum (LP) Gases from Compositional Analysis 1065.720

ASTM D2622-07, Standard Test Method for Sulfur in Petroleum Products by Wavelength Dispersive X-ray 

Fluorescence Spectrometry

1065.703, 

1065.710

ASTM D2713-91 (Reapproved 2001), Standard Test Method for Dryness of Propane (Valve Freeze Method) 1065.720

ASTM D2784-06, Standard Test Method for Sulfur in Liquefied Petroleum Gases (Oxy-Hydrogen Burner or 

Lamp) 1065.720

ASTM D2880-03, Standard Specification for Gas Turbine Fuel Oils 1065.701

ASTM D2986-95a (Reapproved 1999), Standard Practice for Evaluation of Air Assay Media by the 

Monodisperse DOP (Dioctyl Phthalate) Smoke Test 1065.170

ASTM D3231-07, Standard Test Method for Phosphorus in Gasoline 1065.710

ASTM D3237-06e01, Standard Test Method for Lead in Gasoline By Atomic Absorption Spectroscopy 1065.710
ASTM D4052-96e01 (Reapproved 2002), Standard Test Method for Density and Relative Density of Liquids 

by Digital Density Meter 1065.703

ASTM D4814-07a, Standard Specification for Automotive Spark-Ignition Engine Fuel 1065.701

ASTM D5186-03, Standard Test Method for Determination of the Aromatic Content and Polynuclear 

Aromatic Content of Diesel Fuels and Aviation Turbine Fuels By Supercritical Fluid Chromatography 1065.703

ASTM D5191-07, Standard Test Method for Vapor Pressure of Petroleum Products (Mini Method) 1065.710

ASTM D5797-07, Standard Specification for Fuel Methanol (M70-M85) for Automotive Spark-Ignition 

Engines 1065.701

ASTM D5798-07, Standard Specification for Fuel Ethanol (Ed75-Ed85) for Automotive Spark-Ignition 

Engines 1065.701

ASTM D6615-06, Standard Specification for Jet B Wide-Cut Aviation Turbine Fuel 1065.701

ASTM D6751-07b, Standard Specification for Biodiesel Fuel Blend Stock (B100) for Middle Distillate Fuels 1065.701

ASTM D6985-04a, Standard Specification for Middle Distillate Fuel Oil—Military Marine Applications 1065.701

ASTM F1471-93 (Reapproved 2001), Standard Test Method for Air Cleaning Performance of a HighEfficiency Particulate Air Filter System 1065.1001

(b) ISO material. Table 2 of this section lists material from the International 

Organization for Standardization that we have incorporated by reference. The first 

column lists the number and name of the material. The second column lists the section of 

this part where we reference it. Anyone may purchase copies of these materials from the 

International Organization for Standardization, Case Postale 56, CH-1211 Geneva 20, 

Switzerland or www.iso.org. Table 2 follows:

Table 2 of §1065.1010–ISO materials

Document number and name Part 1065 

reference

ISO 2719:2002, Determination of flash point -- Pensky-Martens closed cup method 1065.705

ISO 3016:1994, Petroleum products -- Determination of pour point 1065.705

ISO 3104:1994/Cor 1:1997, Petroleum products -- Transparent and opaque liquids -- Determination of 

kinematic viscosity and calculation of dynamic viscosity

1065.705

ISO 3675:1998, Crude petroleum and liquid petroleum products -- Laboratory determination of density --

Hydrometer method

1065.705

ISO 3733:1999, Petroleum products and bituminous materials -- Determination of water -- Distillation method 1065.705

ISO 6245:2001, Petroleum products -- Determination of ash 1065.705

ISO 8217:2005, Petroleum products -- Fuels (class F) -- Specifications of marine fuels 1065.705

ISO 8754:2003, Petroleum products -- Determination of sulfur content -- Energy-dispersive X-ray 

fluorescence spectrometry

1065.705

ISO 10307-2:1993, Petroleum products -- Total sediment in residual fuel oils -- Part 2: Determination using 

standard procedures for ageing

1065.705

ISO 10370:1993/Cor 1:1996, Petroleum products -- Determination of carbon residue -- Micro method 1065.705

ISO 10478:1994, Petroleum products -- Determination of aluminium and silicon in fuel oils -- Inductively 

coupled plasma emission and atomic absorption spectroscopy methods

1065.705

ISO 12185:1996/Cor 1:2001, Crude petroleum and petroleum products -- Determination of density --

Oscillating U-tube method

1065.705

ISO 14596:2007, Petroleum products -- Determination of sulfur content -- Wavelength-dispersive X-ray 

fluorescence spectrometry

1065.705

ISO 14597:1997, Petroleum products -- Determination of vanadium and nickel content -- Wavelengthdispersive X-ray fluorescence spectrometry1065.705

ISO 14644-1:1999, Cleanrooms and associated controlled environments 1065.190

 

 * * * * *

(c) NIST material. Table 3 of this section lists material from the National Institute of 

Standards and Technology that we have incorporated by reference. The first column lists 
the number and name of the material. The second column lists the section of this part 

where we reference it. Anyone may purchase copies of these materials from the 

Government Printing Office, Washington, DC 20402 or download them free from the 

Internet at www.nist.gov. Table 3 follows: 

Table 3 of §1065.1010–NIST materials 

Document number and name Part 1065 reference

NIST Special Publication 811, 2008 Edition, Guide for the Use of the International 

System of Units (SI), Barry N. Taylor, Physics Laboratory, and Ambler Thompson, 

Technology Services and Barry N. Taylor, Physics Laboratory, March 2008

1065.20(a) and (e), 

1065.1005 

NIST Technical Note 1297, 1994 Edition, Guidelines for Evaluating and Expressing 

the Uncertainty of NIST Measurement Results, Barry N. Taylor and Chris E. Kuyatt 1065.1001 

(d) SAE material. Table 4 of this section lists material from the Society of Automotive 

Engineering that we have incorporated by reference. The first column lists the number 

and name of the material. The second column lists the sections of this part where we 

reference it. Anyone may purchase copies of these materials from the Society of 

Automotive Engineers, 400 Commonwealth Drive, Warrendale, PA 15096 or 

www.sae.org. Table 4 follows:

Table 4 of §1065.1010–SAE materials

Document number and name Part 1065 reference

“Optimization of Flame Ionization Detector for Determination of Hydrocarbon in Diluted 

Automotive Exhausts,” Reschke Glen D., SAE 770141 1065.360

(e) California Air Resources Board material. Table 5 of this section lists material from 

the California Air Resources Board that we have incorporated by reference. The first 

column lists the number and name of the material. The second column lists the sections 

of this part where we reference it. Anyone may get copies of these materials from the 

California Air Resources Board 9528 Telstar Ave., El Monte, California 91731. Table 5 

follows:

Table 5 of §1065.1010–California Air Resources Board materials

Document number and name Part 1065 reference

“California Non-Methane Organic Gas Test Procedures,” Amended July 30, 2002, Mobile Source 

Division, California Air Resources Board 1065.805

(f) Institute of Petroleum material. Table 6 of this section lists the Institute of Petroleum

standard test methods material from the Energy Institute that we have incorporated by 

reference. The first column lists the number and name of the material. The second 

column lists the section of this part where we reference it. Anyone may purchase copies 

of these materials from the Energy Institute, 61 New Cavendish Street , London, W1G 

7AR, UK , +44 (0)20 7467 7100 or www.energyinst.org.uk. Table 6 follows:

Table 6 of §1065.1010–Institute of Petroleum materials

Document number and name Part 1065 reference

IP-470, Determination of Aluminum, silicon, vanadium, nickel, iron, calcium, zinc, and sodium in 

residual fuels by atomic absorption spectrometry 1065.705

IP-500 Determination of the phosphorus content of residual fuels by ultra-violet spectrometry 1065.705

IP-501 Determination of aluminium, silicon, vanadium, nickel, iron, sodium, calcium, zinc and 1065.705

Formatted Table
phosphorus in residual fuel oil by ashing, fusion and inductively coupled plasma emission 

spectrometry

* * * * *

* * * * *

 
91. A new part 1066 is added to subchapter U to read as follows: 

Part 1066—Vehicle-Testing Procedures 

Subpart A—Applicability and General Provisions 

Sec. 

1066.1 Applicability. 

1066.2 Submitting information to EPA under this part. 

1066.5 Overview of this part 1066 and its relationship to the standard-setting part. 

1066.10 Other procedures. 

1066.15 Overview of test procedures. 

1066.20 Units of measure and overview of calculations. 

1066.25 Recordkeeping. 

Subpart B—Equipment, Fuel, and Gas Specifications 

1066.201101 Overview. 

 

Subpart C—Dynamometer Specifications 

1066.11066.201 Dynamometer Overviewoverview. 

1066.11066.210 Dynamometers. 

1066.11066.215 Summary of verification and calibration procedures for chassis 

dynamometers. 

1066.11066.220 Linearity verification. 

1066.11066.225 Roll runout and diameter verification procedure. 

1066.11066.230 Time verification procedure. 

1066.11066.235 Speed verification procedure. 

1066.11066.240 Torque transducer verification and calibration.

1066.11066.245 Response time verification. 

1066.11066.250 Base inertia verification. 

1066.11066.255 Parasitic loss verification. 

1066.11066.260 Parasitic friction compensation evaluation. 

1066.11066.265 Acceleration and deceleration verification. 

1066.11066.270 Unloaded coastdown verification. 

1066.11066.280 Driver’s aid. 

 Subpart CDD—Coastdown 

1066.21066.301 Overview of coastdown procedures. 

1066.21066.310 Coastdown procedures for heavy-duty vehicles. 

 Subpart DEE—Vehicle Preparation and Running a Test 

1066.31066.401 Overview. 
1066.31066.404 Road load power and test weight determination.

1066.31066.407 Vehicle preparation and preconditioning. 

1066.31066.410 Dynamometer test procedure. 

1066.31066.420 Pre-test verification procedures and pre-test data collection. 

1066.31066.425 Engine starting and restarting. 

1066.31066.430 Performing emission tests 

Subpart EFF—Hybrids 

1066.401 501 Overview. 

 Subpart F—[Reserved]

Subpart G—Calculations 

1066.601 Overview. 

1066.610 Mass-based and molar-based exhaust emission calculations. 

 Subpart H—Definitions and Other Reference Material 

1066.701 Definitions. 

1066.705 Symbols, abbreviations, acronyms, and units of measure. 

1066.710 Reference materials. 

Authority: 42 U.S.C. 7401 - 7671q. 

Subpart A—Applicability and General Provisions 

§1066.1 Applicability. 

(a) This part describes the procedures that apply to testing we require for the following 

vehicles: 

(1) Model year 2014 and later heavy-duty highway vehicles we regulate under 40 CFR 

part 1037 that are not subject to chassis testing for exhaust emissions under 40 CFR part 

86. 

(2) [Reserved] 

(b) The procedures of this part may apply to other types of vehicles, as described in this 

part and in the standard-setting part. 

(c) The term “you” means anyone performing testing under this part other than EPA. 

(1) This part is addressed primarily to manufacturers of vehicles, but it applies equally to 

anyone who does testing under this part for such manufacturers. 

(2) This part applies to any manufacturer or supplier of test equipment, instruments, 

supplies, or any other goods or services related to the procedures, requirements, 

recommendations, or options in this part. 

(d) Paragraph (a) of this section identifies the parts of the CFR that define emission 

standards and other requirements for particular types of vehicles. In this part, we refer to 

each of these other parts generically as the ''standard-setting part.'' For example, 40 CFR 

part 1037 is the standard-setting part for heavy-duty highway vehicles. 
(e) Unless we specify otherwise, the terms “procedures” and “test procedures” in this part 

include all aspects of vehicle testing, including the equipment specifications, calibrations, 

calculations, and other protocols and procedural specifications needed to measure 

emissions. 

(f) For additional information regarding these test procedures, visit our Web site at 

www.epa.gov, and in particular http://www.epa.gov/nvfel/testing/regulations.htm. 

§1066.2 Submitting information to EPA under this part. 

(a) You are responsible for statements and information in your applications for 

certification, requests for approved procedures, selective enforcement audits, laboratory 

audits, production-line test reports, field test reports, or any other statements you make to 

us related to this part 1066. If you provide statements or information to someone for 

submission to EPA, you are responsible for these statements and information as if you 

had submitted them to EPA yourself. 

(b) In the standard-setting part and in 40 CFR 1068.101, we describe your obligation to 

report truthful and complete information and the consequences of failing to meet this 

obligation. See also 18 U.S.C. 1001 and 42 U.S.C. 7413(c)(2). This obligation applies 

whether you submit this information directly to EPA or through someone else. 

(c) We may void any certificates or approvals associated with a submission of 

information if we find that you intentionally submitted false, incomplete, or misleading 

information. For example, if we find that you intentionally submitted incomplete 

information to mislead EPA when requesting approval to use alternate test procedures, 

we may void the certificates for all engine families certified based on emission data 

collected using the alternate procedures. This would also apply if you ignore data from 

incomplete tests or from repeat tests with higher emission results. 

(d) We may require an authorized representative of your company to approve and sign 

the submission, and to certify that all of the information submitted is accurate and 

complete. This includes everyone who submits information, including manufacturers and 

others. 

(e) See 40 CFR 1068.10 for provisions related to confidential information. Note however 

that under 40 CFR 2.301, emission data is generally not eligible for confidential 

treatment. 

(f) Nothing in this part should be interpreted to limit our ability under Clean Air Act 

section 208 (42 U.S.C. 7542) to verify that vehicles conform to the regulations. 

§1066.5 Overview of this part 1066 and its relationship to the standard-setting part. 

(a) This part specifies procedures that can apply generally to testing various categories of 

vehicles. See the standard-setting part for directions in applying specific provisions in 

this part for a particular type of vehicle. Before using this part's procedures, read the 

standard-setting part to answer at least the following questions: 

(1) What drive schedules must I use for testing? 

(2) Should I warm up the test vehicle before measuring emissions, or do I need to 

measure cold-start emissions during a warm-up segment of the duty cycle? 

(3) Which exhaust constituents do I need to measure? Measure all exhaust constituents 

that are subject to emission standards, any other exhaust constituents needed for 

calculating emission rates, and any additional exhaust constituents as specified in the 
standard-setting part. We may approve your request to omit measurement of N2O and 

CH4 for a vehicle, provided it is not subject to an N2O or CH4 emission standard and we 

determine that other information is available to give us a reasonable basis for estimating 

or approximating the vehicle’s emission rates. 

(4) Do any unique specifications apply for test fuels? 

(5) What maintenance steps may I take before or between tests on an emission-data 

vehicle? 

(6) Do any unique requirements apply to stabilizing emission levels on a new vehicle? 

(7) Do any unique requirements apply to test limits, such as ambient temperatures or 

pressures? 

(8) Is field testing required or allowed, and are there different emission standards or 

procedures that apply to field testing? 

(9) Are there any emission standards specified at particular operating conditions or 

ambient conditions? 

(10) Do any unique requirements apply for durability testing? 

(b) The testing specifications in the standard-setting part may differ from the 

specifications in this part. In cases where it is not possible to comply with both the 

standard-setting part and this part, you must comply with the specifications in the 

standard-setting part. The standard-setting part may also allow you to deviate from the 

procedures of this part for other reasons. 

(c) The following table shows how this part divides testing specifications into subparts: 

Table 1 of §1066.5—Description of Part 1066 subparts. 

This subpart Describes these specifications or procedures 

Subpart A Applicability and general provisions. 

Subpart B Equipment for testing. 

Subpart C Coastdowns for testing.Dynamometer specifications.

Subpart D How to prepare your vehicle and run an emissions test over a 

predetermined duty cycle.Coastdowns for testing.

Subpart E How to prepare your vehicle and run an emission test with hybrid 

vehicles. 

Subpart F Reserved.How to test hybrid vehicles.

Subpart G Test procedure calculations. 

Subpart H Definitions and reference material. 

§1066.10 Other procedures. 

(a) Your testing. The procedures in this part apply for all testing you do to show 

compliance with emission standards, with certain exceptions listed in this section. In 

some other sections in this part, we allow you to use other procedures (such as less 

precise or less accurate procedures) if they do not affect your ability to show that your 

vehicles comply with the applicable emission standards. This generally requires emission 

levels to be far enough below the applicable emission standards so that any errors caused 

by greater imprecision or inaccuracy do not affect your ability to state unconditionally 

that the engines meet all applicable emission standards. 
(b) Our testing. These procedures generally apply for testing that we do to determine if 

your vehicles comply with applicable emission standards. We may perform other testing 

as allowed by the Act. 

(c) Exceptions. We may allow or require you to use procedures other than those 

specified in this part in the following cases, which may apply tofor laboratory testing, 

field testing, or both. We intend to publicly announce when we allow or require such 

exceptions. The provisions of , as described in 40 CFR 1065.10(c) apply for testing 

under this part.). All of the test procedures noted there as exceptions to the specified 

procedures are considered generically as "other procedures." Note that the terms "special 

procedures" and "alternate procedures" have specific meanings; "special procedures" are 

those allowed by 40 CFR 1065.10(c)(2) and "alternate procedures" are those allowed by 

40 CFR 1065.10(c)(7). If we require you to request approval to use other procedures 

under this paragraph (c), you may not use them until we approve your request. 

§1066.15 Overview of test procedures. 

This section outlines the procedures to test vehicles that are subject to emission standards. 

(a) In the standard-setting part, we set emission standards in g/mile (or g/km), for the 

following constituents: 

(1) Total oxides of nitrogen, NOx. 

(2) Hydrocarbons (HC), which may be expressed in the following ways: 

(i) Total hydrocarbons, THC. 

(ii) Nonmethane hydrocarbons, NMHC, which results from subtracting methane (CH4) 

from THC. 

(iii) Total hydrocarbon-equivalent, THCE, which results from adjusting THC 

mathematically to be equivalent on a carbon-mass basis. 

(iv) Nonmethane hydrocarbon-equivalent, NMHCE, which results from adjusting NMHC 

mathematically to be equivalent on a carbon-mass basis. 

(3) Particulate mass, PM. 

(4) Carbon monoxide, CO. 

(b) Note that some vehicles may not be subject to standards for all the emission 

constituents identified in paragraph (a) of this section. 

(c) We generally set emission standards over test intervals and/or drive schedules, as 

follows: 

(1) Vehicle operation. Testing may involve measuring emissions and miles travelled in a 

laboratory-type environment or in the field. The standard-setting part specifies how test 

intervals are defined for field testing. Refer to the definitions of “duty cycle” and “test 

interval” in §1066.701. Note that a single drive schedule may have multiple test intervals 

and require weighting of results from multiple test phases to calculate a composite 

distance-based emission value to compare to the standard. 

(2) Constituent determination. Determine the total mass of each constituent over a test 

interval by selecting from the following methods: 

(i) Continuous sampling. In continuous sampling, measure the constituent’s 

concentration continuously from raw or dilute exhaust. Multiply this concentration by 

the continuous (raw or dilute) flow rate at the emission sampling location to determine 

the constituent’s flow rate. Sum the constituent’s flow rate continuously over the test 

interval. This sum is the total mass of the emitted constituent. 
(ii) Batch sampling. In batch sampling, continuously extract and store a sample of raw or 

dilute exhaust for later measurement. Extract a sample proportional to the raw or dilute 

exhaust flow rate, as applicable. You may extract and store a proportional sample of 

exhaust in an appropriate container, such as a bag, and then measure HC, CO, and NOx

concentrations in the container after the test phase. You may deposit PM from 

proportionally extracted exhaust onto an appropriate substrate, such as a filter. In this 

case, divide the PM by the amount of filtered exhaust to calculate the PM concentration. 

Multiply batch sampled concentrations by the total (raw or dilute) flow from which it was 

extracted during the test interval. This product is the total mass of the emitted 

constituent. 

(iii) Combined sampling. You may use continuous and batch sampling simultaneously 

during a test interval, as follows: 

(A) You may use continuous sampling for some constituents and batch sampling for 

others. 

(B) You may use continuous and batch sampling for a single constituent, with one being 

a redundant measurement, subject to the provisions of 40 CFR 1065.201. 

(d) Refer to the standard-setting part for calculations to determine g/mile emission rates. 

(e) The regulation highlights several specific cases where good engineering judgment is 

especially relevant. You must use good engineering judgment for all aspects of testing 

under this part, not only for those provisions where we specifically re-state this 

requirement. 

§1066.20 Units of measure and overview of calculations. 

(a) System of units. The procedures in this part follows both conventional English Units 

and the International System of Units (SI), as detailed in NIST Special Publication 811, 

1995 Edition, “Guide for the Use of the International System of Units (SI),” which we 

incorporate by reference in §1066.710. This document is available on the Internet at 

http://www.nist.gov/physlab/pubs/sp811.

(b) Units conversion. Use good engineering judgment to convert units between 

measurement systems as needed. The following conventions are used throughout this 

document and should be used to convert units as applicable: 

(1) 1 hp = 33,000 ft·lbf/min = 550 ft·lbf/s = 0.7457 kW. 

(2) 1 lbf = 32.174 ft·lbm/s2 = 4.4482 N.

(3) 1 inch = 25.4 mm. 

(c) Rounding. Unless the standard-settingThe rounding provisions of 40 CFR 1065.20 

apply for calculations in this part. This generally specifies otherwise,that you round only 

final values, but not intermediate values. Round values to the number of significant 

digits necessary to match the number of decimal places of the applicable standard or 

specification. For information not related to standards or specifications, Use good 

engineering judgment to record the appropriate number of significant digits for all 

measurements. 

(d) Interpretation of ranges. Interpret a range as a tolerance unless we explicitly identify 

it as an accuracy, repeatability, linearity, or noise specification. See 40 CFR 1065.1001 

for the definition of tolerance. In this part, we specify two types of ranges: 
(1) Whenever we specify a range by a single value and corresponding limit values above 

and below that value, target any associated control point to that single value. Examples 

of this type of range include “±10 % of maximum pressure”, or “(30 ±10) kPa”. 

(2) Whenever we specify a range by the interval between two values, you may target any 

associated control point to any value within that range. An example of this type of range 

is “(40 to 50) kPa”. 

(e) Scaling of specifications with respect to an applicable standard. Because this part 

1066 is applicableapplies to a wide range of vehicles and emission standards, some of the 

specifications in this part are scaled with respect to a vehicle’s applicable standard or 

weight. This ensures that the specification will be adequate to determine compliance, but 

not overly burdensome by requiring unnecessarily high-precision equipment. Many of 

these specifications are given with respect to a “flow-weighted mean” that is expected at 

the standard or during testing. Flow-weighted mean is the mean of a quantity after it is 

weighted proportional to a corresponding flow rate. For example, if a gas concentration 

is measured continuously from the raw exhaust of an engine, its flow-weighted mean 

concentration is the sum of the products of each recorded concentration times its 

respective exhaust flow rate, divided by the sum of the recorded flow rates. As another 

example, the bag concentration from a CVS system is the same as the flow-weighted 

mean concentration, because the CVS system itself flow-weights the bag concentration. 

Refer to 40 CFR 1065.602 for information needed to estimate and calculate flowweighted means. 

§1066.25 Recordkeeping. 

The procedures in this part include various requirements to record data or other 

information. Refer to the standard-setting part regarding recordkeeping requirements. If 

the standard-setting part does not specify recordkeeping requirements, store these records 

in any format and on any media and keep them readily available for one year after you 

send an associated application for certification, or one year after you generate the data if 

they do not support an application for certification. You must promptly send us 

organized, written records in English if we ask for them. We may review them at any 

time. 

Subpart B—Equipment, Fuel, and Gas Specifications 

§1066.101 Overview. 

(a) This subpart addresses equipment related to emission testing, as well as test fuels and 

analytical gases. This section addresses emission sampling and analytical equipment, test 

fuels, and analytical gases. 

 The remainder of this subpart addresses chassis dynamometers and related equipment.

(b) The provisions of 40 CFR part 1065 specify engine-based procedures for measuring 

emissions. Except as specified otherwise in this part, the provisions of 40 CFR part 1065 

apply for testing required by this part as follows:

(1) The provisions of 40 CFR 1065.140 through 1065.195 specify equipment for exhaust 

dilution and sampling systems. 

(2) The provisions of 40 CFR part 1065, subparts C and D, specify measurement 

instruments and their calibrations. 
(3) The provisions of 40 CFR part 1065, subpart H, specify fuels, engine fluids, and 

analytical gases. 

(4) The provisions of 40 CFR part 1065, subpart J, describe how to measure emissions 

from vehicles operating outside of a laboratory, except that provisions related to 

measuring engine work do not apply. 

(c) The provisions of this subpart are intended to specify systems that can very accurately 

and precisely measure emissions from motor vehicles. We may waive or modify the 

specifications and requirements of this part for testing highway motorcycles or nonroad 

vehicles, consistent with good engineering judgment. For example, it may be appropriate 

to allow the use of a hydrokinetic dynamometer that is not able to meet all the 

performance specifications described in this subpart. 

Subpart C—Dynamometer Specifications 

§1066.201 Dynamometer overview.

This subpart addresses chassis dynamometers and related equipment. 

§1066.110 210 Dynamometers.

(a) General requirements. A chassis dynamometer typically uses electrically generated 

load forces combined with theits rotational inertia of the dynamometer to recreate the 

mechanical inertia and frictional forces that a vehicle exerts on road surfaces (known as 

“road load”). Load forces are calculated using vehicle-specific coefficients and response 

characteristics. The load forces are applied to the vehicle tires by rolls connected to 

intermediate motor/absorbers. The dynamometer uses a load cell to measure the forces 

the dynamometer rolls apply to the vehicle’s tires. 

(b) Accuracy and precision. The dynamometer’s output values for road load must be 

NIST-traceable. We may determine traceability to a specific international standards 

organization to be sufficient to demonstrate NIST-traceability. The force-measurement 

system must be capable of indicating force readings to a resolution of ±0.1 05 % of the 

maximum forces simulated by the dynamometer or ±0.9 N (±0.2 lbf,), whichever is 

greater, during a test. 

(c) Test cycles. The dynamometer must be capable of fully simulating applicable test 

cycles for the vehicles being tested as referenced in the corresponding standard-setting 

part. 

(1) For light-duty vehicles and for heavy-duty vehicles with a gross vehicle weight rating 

(GVWR) at or below 14,000 lbs, the dynamometer must be able to fully simulate a 

driving schedule with a maximum speed of 36 m/s (80.3 mph) and a maximum 

acceleration rate of 3.6 m/s2 (8.0 mph/s) in two-wheel drive and four-wheel drive 

configurations. Note that your dynamometer does not have to meet this requirement for 

vehicles larger than vehicles tested. 

(2) For heavy-duty vehicles with GVWR above 14,000 lbs, the dynamometer must be 

able to fully simulate a driving schedule with a maximum speed of 29 m/s (65.0 mph)

and a maximum acceleration rate of 1.3.0 m/s2 (3 mph/s) in either two-wheel drive or 

four-wheel drive configurations. 

(d) Component requirements. The dynamometer must have an independent drive roll for 

each axle being driven by the vehicle.meet the following specifications: 
(1) For light-duty vehicles and for heavy-duty vehicles with GVWR at or below 14,000 

lbs, the nominal roll diameter must be 1.20 to 1.25 meters (this is commonly referred to 

as a 48-inch roll dynamometer).. The dynamometer must have an independent drive roll 

for each axle being driven by the vehicle during an emission test. 

(2) For heavy-duty vehicles with GVWR above 14,000 lbs, the nominal roll diameter 

must be at least 1.20 meters and no greater than 13.85 3.10 meters. The dynamometer 

maymust have an independent drive roll for each axle being driven by the vehicle or 

alternatively up to, except that two driven axles may useshare a single drive roll. Use 

good engineering judgment to ensure that the dynamometer roll diameter is large enough 

to provide sufficient tire-roll contact area for avoidingto avoid tire overheating and power 

losses from tire-roll slippage. 

(3) If you measure force and speed at 10 Hz or faster, you may use good engineering 

judgment to convert those measurements to 1-Hz, 2-Hz, or 5-Hz values. 

(4) The load applied by the dynamometer simulates forces acting on the vehicle during 

normal driving according to the following equation:

2 i i-1

i i i

i i-1

S S FR A B S C S M

t t

−

= + ⋅ + ⋅ + ⋅

−

Where: 

FR = total road-load force to be applied at the surface of the roll. The total force is the 

sum of the individual tractive forces applied at each roll surface. 

i = a counter to indicate a point in time over the driving schedule. For a dynamometer 

operating at 10-Hz intervals over a 600-second driving schedule, the maximum value of i

is 6,000. 

A = constant value representing the vehicle’s frictional load in lbf or newtons. See 

subpart C of this part. 

B = coefficient representing load from drag and rolling resistance, which are a function of 

vehicle speed, in lbf/mph or newtons/kphN·s/m. See subpart C of this part. 

S = linear speed at the roll surfaces as measured by the dynamometer, in mph or kphm/s. 

Let Si-1 = 0. 

C = coefficient representing aerodynamic effects, which are a function of vehicle speed 

squared, in lbf/mph2 or newton/kph2N·s

2

/m2. See subpart C of this part. 

M = mass of vehicle in lbm or kg. Determine the vehicle’s mass based on the test weight, 

taking into account the effect of rotating axles, as specified in §1066.31066.404310(b)(7) 

and dividing the weight by the acceleration due to gravity as specified in 40 CFR 

1065.630, consistent with good engineering judgment. 

t = elapsed time in the driving schedule as measured by the dynamometer, in seconds. 

Let ti-1 = 0. 

(5) The dynamometer must be designed to Measured values ofgenerallygenerally apply 

an actual road-load force may not differ from the corresponding calculated values at any 

operating conditions by more thanwithin ± within ±1 % or ±9.8 N (±2.2 lbf, whichever is 

greater,) of the reference value, whichever is greater. Dynamometers that do not fully 

meet this specification may be used consistent with good engineering judgment. For 

example, slightly higher errors may be permissible during highly transient operation. 
(e) Dynamometer manufacturer instructions. This part specifies that you follow the 

dynamometer manufacturer’s recommended procedures for things such as calibrations 

and general operation. If you perform testing with a dynamometer that you manufactured 

or if you otherwise do not have these recommended procedures, use good engineering 

judgment to establish the additional procedures and specifications we specify in this part, 

unless we specify otherwise. Keep records to describe these recommended procedures 

and how they are consistent with good engineering judgment. 

§1066.11066.215 Summary of verification and calibration procedures for chassis 

dynamometers. 

(a) Overview. This section describes the overall process for verifying and calibrating the 

performance of chassis dynamometers.

(b) Scope and frequency. The following table summarizes the required and 

recommended calibrations and verifications described in this subpart and indicates when 

these have to be performedthey must occur: 

Table 1 of §1066.11066.215–Summary of required dynamometer calibrations and 

verifications. 

Type of calibration or verification Minimum frequencya

§1066.11066.220: Linearity 

verification 

Speed: Upon initial installation, within 370 days before testing, and after 

major maintenance. 

Torque (load): Upon initial installation, within 370 days before testing, and 

after major maintenance. 

§1066.11066.225: Roll runout and 

diameter Upon initial installation and after major maintenance. 

§1066.11066.230: Time Upon initial installation and after major maintenance. 

§1066.11066.235: Speed 

measurement 

Upon initial installation, within 35 370 days before testing, and after major 

maintenance. 

§1066.11066.240: Torque (load) 

transducer 

Upon initial installation, within 370 days before testing, and after major 

maintenance. 

§1066.11066.245: Response time Upon initial installation and after major maintenance. 

§1066.11066.250: Base inertia Upon initial installation and after major maintenance. 

§1066.11066.255: Parasitic loss Upon initial installation, within 7 days before testing, and after major 

maintenance.

§1066.11066.260: Parasitic friction 

compensation evaluation

Upon initial installation, within 7 days before testing, and after major 

maintenance.

§1066.11066.265: Acceleration and 

deceleration Upon initial installation and after major maintenance. 

§1066.11066.270: Unloaded 

coastdown 

Upon initial installation, within 7 days before testing, and after major 

maintenance. 

a

Perform calibrations and verifications more frequently, according to measurement system manufacturer instructions 

and good engineering judgment. 

(c) Automated dynamometer verifications and calibrations. In some cases, dynamometers 

are designed with internal diagnostic and control features to accomplish the verifications 

and calibrations specified in this subpart. You may use these automated functions instead 

of following the procedures we specify in this subpart to demonstrate compliance with 

applicable requirements, consistent with good engineering judgment. 

(d) Sequence of verifications and calibrations. Upon initial installation and after major 

maintenance, perform the verifications and calibrations in the same sequence as noted in 

Table 1 of this section. At other times, you may need to perform specific verifications or 

calibration in a certain sequence, as noted in this subpart. 
(e) Corrections. Unless the regulations directs otherwise, if the dynamometer fails to meet 

any specified calibration or verification, make any necessary adjustments or repairs such 

that the dynamometer meets the specification before running a test. Repairs required to 

meet specifications are generally considered major maintenance under this part. 

§1066.11066.220 Linearity verification. 

(a) Scope and frequency. Perform linearity verifications as specified in Table 1 of this 

section at least as frequently as indicated in the table, consistent with the dynamometer 

manufacturer’s recommendationsupon initial installation, within 370 days before testing,

and good engineering judgment.after major maintenance. Note that these linearity 

verifications may replace requirements we previously referred to as calibrations. The 

intent of linearity verification is to determine that a measurement system responds 

accurately and proportionally over the measurement range of interest. Linearity 

verification generally consists of introducing a series of at least 10 reference values (or 

the manufacturer’s recommend number of reference values) to a measurement system. 

The measurement system quantifies each reference value. The measured values are then 

collectively compared to the reference values by using a least-squares linear regression 

and the linearity criteria specified in Table 1 of this section. 

(b) Performance requirements. If a measurement system does not meet the applicable 

linearity criteria in Table 1 of this section, correct the deficiency by re-calibrating, 

servicing, or replacing components as needed. Repeat the linearity verification after 

correcting the deficiency to ensure that the measurement system meets the linearity 

criteria. Before you may use a measurement system that does not meet linearity criteria, 

you must demonstrate to us that the deficiency does not adversely affect your ability to 

demonstrate compliance with the applicable standards. 

(c) Procedure. Use the following linearity verification protocol, or use good engineering 

judgment to develop a different protocol that satisfies the intent of this section, as 

described in paragraph (a) of this section: 

(1) In this paragraph (c), the letter “y” denotes a generic measured quantity, the 

superscript over-bar denotes an arithmetic mean (such as y ), and the subscript “ref” 

denotes the known or reference quantity being measured. 

(2) Operate a dynamometer system at the specified temperatures and pressures. This may 

include any specified adjustment or periodic calibration of the dynamometer system. 

(3) Set dynamometer speed and torque to zero and apply the dynamometer brake to 

ensure a zero-speed condition. 

(4) Span the dynamometer speed or torque signal. 

(5) After spanning, check for zero speed and torque. Use good engineering judgment to 

determine whether or not to rezero or re-span before continuing. 

(6) For both speed and torque, use the dynamometer manufacturer’s recommendations 

and good engineering judgment to select reference values, yrefi, that cover a range of 

values that you expect would prevent extrapolation beyond these values during emission 

testing. We recommend selecting zero speed and zero torque as reference values for the 

linearity verification. 

(7) Use the dynamometer manufacturer’s recommendations and good engineering 

judgment to select the order in which you will introduce the series of reference values. 

For example, you may select the reference values randomly to avoid correlation with 
previous measurements or the influence of hysteresis; you may select reference values in 

ascending or descending order to avoid long settling times of reference signals; or you 

may select values to ascend and then descend to incorporate the effects of any instrument 

hysteresis into the linearity verification. 

(8) Set the dynamometer to operate at a reference condition. 

(9) Allow time for the dynamometer to stabilize while it measures the reference values. 

(10) At a recording frequency of at least 1 Hz, measure speed and torque values for 30 

seconds and record the arithmetic mean of the recorded values, i

y . Refer to 40 CFR 

1065.602 for an example of calculating an arithmetic mean. 

(11) Repeat the steps in paragraphs (c)(8) though (10) of this section until you measure 

speeds and torques at each of the reference conditions. 

(12) Use the arithmetic means, i

y , and reference values, yrefi , to calculate least-squares 

linear regression parameters and statistical values to compare to the minimum 

performance criteria specified in Table 1 of this section. Use the calculations described 

in 40 CFR 1065.602. Using good engineering judgment, you may weight the results of 

individual data pairs (i.e., (yrefi, i

y )), in the linear regression calculations. 

Table 1 of §1066.11066.220– 

Dynamometer measurement systems that require linearity verifications 

Measurement 

system Quantity Linearity criteria 

|| xmin(a1-1)+a0 | a1 SEE r

2

Speed S <0.05 % · max S 0.98-1.02 <2 % · max S >0.990 

Torque (load) T <1 % · Tmax 0.98-1.02 <2 % · Tmax >0.990 

§1066.11066.225 Roll runout and diameter verification procedure. 

(a) Overview. This section describes the verification procedure for roll runout and roll 

diameter. Roll runout is a measure of the variation in roll radius around the 

circumference of the roll. 

(b) Scope and frequency. Perform these verifications upon initial installation and after 

major maintenance. 

(c) Roll runout procedure. Verify roll runout as follows: 

(1) Perform this verification with laboratory and dynamometer temperatures stable and at 

equilibrium. Release the roll brake and shut off power to the dynamometer. Remove any 

dirt, rubber, rust, and debris from the roll surface. Mark measurement locations on the 

roll surface using a permanent marker. Mark the roll at a minimum of four equally 

spaced locations across the roll width; we recommend taking measurements every 150 

mm across the roll. Secure the marker to the deck plate adjacent to the roll surface and 

slowly rotate the roll to mark a clear line around the roll circumference. Repeat this 

process for all measurement locations. 

(2) Measure roll runout using a dial indicator with a probe that allows for measuring the 

position of the roll surface relative to the roll centerline as it turns through a complete 

revolution. The dial indicator must have a magnetic base assembly or other means of 

being securely mounted adjacent to the roll. The dial indicator must have sufficient range 

to measure roll runout at all points, with a minimum accuracy and precision of ±0.025 

mm. Calibrate the dial indicator according to the instrument manufacturer’s instructions. 

(3) Position the dial indicator adjacent to the roll surface at the desired measurement 

location. Position the shaft of the dial indicator perpendicular to the roll such that the 
point of the dial indicator is slightly touching the surface of the roll and can move freely 

through a full rotation of the roll. Zero the dial indicator according to the instrument 

manufacturer’s instructions. Avoid distortion of the runout measurement from the weight 

of a person standing on or near the mounted dial indicator. 

(4) Slowly turn the roll through a complete rotation and record the maximum and 

minimum values from the dial indicator. Calculate runout fromas the difference between 

these maximum and minimum values. 

(5) Repeat the steps in paragraphs (c)(3) and (4) of this section for all measurement 

locations. 

(6) The roll runout must be less than 0.25 mm at all measurement locations. 

(d) Diameter procedure. Verify roll diameter based on the following procedure, or an 

equivalent procedure based on good engineering judgment: 

(1) Prepare the laboratory and the dynamometer as specified in paragraph (c)(1) of this 

section. 

(2) Measure roll diameter using a Pi Tape®. Orient the Pi Tape® to the marker line at 

the desired measurement location with the Pi Tape® hook pointed outward. Temporarily 

secure the Pi Tape® to the roll near the hook end with adhesive tape. Slowly turn the 

roll, wrapping the Pi Tape® around the roll surface. Ensure that the Pi Tape® is flat and 

adjacent to the marker line around the full circumference of the roll. Attach a 2.26-kg 

weight to the hook of the Pi Tape® and position the roll so that the weight dangles freely. 

Remove the adhesive tape without disturbing the orientation or alignment of the Pi 

Tape®. 

(3) Overlap the gage member and the vernier scale ends of the Pi Tape® to read the 

diameter measurement to the nearest 0.01 mm. Follow the manufacturer’s 

recommendation to correct the measurement to 25 20 °C, if applicable. 

(4) Repeat the steps in paragraphs (d)(2) and (3) of this section for all measurement 

locations. 

(5) The measured roll diameter must be within ±0.25 mm of the specified nominal value 

at all measurement locations. You may revise the nominal value to meet this 

specification, as long as you use the corrected nominal value for all calculations in this 

subpart. 

§1066.11066.230 Time verification procedure. 

(a) Overview. This section describes how to verify the accuracy of the dynamometer’s 

timing device. 

(b) Scope and frequency. Perform this verification upon initial installation and after 

major maintenance. 

(c) Procedure. Perform this verification using one of the following procedures: 

(1) WWV method. You may use the time and frequency signal broadcast by NIST from 

radio station WWV as the time standard if the trigger for the dynamometer timing circuit 

has a frequency decoder circuit, as follows: 

(i) Dial station WWV at (303) 499-7111 and listen for the time announcement. Verify 

that the trigger started the dynamometer timer. Use good engineering judgment to 

minimize error in receiving the time and frequency signal. 

(ii) After at least 1000 seconds, re-dial station WWV and listen for the time 

announcement. Verify that the trigger stopped the dynamometer timer. 
(iii) Compare the measured elapsed time, yact, to the corresponding time standard, yref, to 

determine the time error, yerror, using the following equation: 

act ref

error

ref

100 % y yy

y

−

= ⋅

Eq. 1066.11066.230-1 

(2) Ramping method. You may set up an operator-defined ramp function in the signal 

generator to serve as the time standard as follows:

(i) Set up the signal generator to output a marker voltage at the peak of each ramp to 

trigger the dynamometer timing circuit. Output the designated marker voltage to start the 

verification period. 

(ii) After at least 1000 seconds, output the designated marker voltage to end the 

verification period. 

(iii) Compare the measured elapsed time between marker signals, yact, to the 

corresponding time standard, yref, to determine the time error, yerror, using Equation 

1066.11066.230-1. 

(3) Dynamometer coastdown method. You may use a signal generator to output a known 

speed ramp signal to the dynamometer controller to serve as the time standard as follows: 

(i) Generate upper and lower speed values to trigger the start and stop functions of the 

coastdown timer circuit. Use the signal generator to start the verification period. 

(ii) After at least 1000 seconds, use the signal generator to end the verification period. 

(iii) Compare the measured elapsed time between trigger signals, yact, to the 

corresponding time standard, yref, to determine the time error, yerror, using Equation 

1066.11066.230-1. 

(d) Performance evaluation. The time error determined in paragraph (c) of this section 

may not exceed ±0.001 %. 

§1066.11066.235 Speed verification procedure. 

(a) Overview. This section describes how to verify the accuracy and resolution of the 

dynamometer speed determination. 

(b) Scope and frequency. Perform this verification upon initial installation, within 3705

days before testing, and after major maintenance. 

(c) Procedure. Use one of the following procedures to verify the accuracy and resolution 

of the dynamometer speed simulation: 

(1) Pulse method. Connect a universal frequency counter to the output of the 

dynamometer’s speed-sensing device in parallel with the signal to the dynamometer 

controller. The universal frequency counter must be calibrated according to the 

instrument manufacturer’s instructions and be capable of measuring with enough 

accuracy to perform the procedure as specified in this paragraph (c)(1). Make sure the 

instrumentation does not affect the signal to the dynamometer control circuits. 

Determine the speed error as follows: 

(i) Set the dynamometer to speed-control mode. Set the dynamometer speed to a value

between 15 kph4.2 m/s and the maximum speed expected during testing; record the 

output of the frequency counter after 10 seconds. Determine the roll speed, Sact, using the 

following equation: 
roll

act

f d S

n

⋅ ⋅π

=

 Eq. 1066.11066.235-1 

Where: 

f = frequency of the dynamometer speed sensing device, in hrs

-1, accurate to at least four 

significant figures. 

droll = nominal roll diameter, in kmm, accurate to the nearest 0.01 mm, consistent with 

§1066.11066.225(d). 

n = the number of pulses per revolution from the dynamometer roll speed sensor. 

Example:

f = 2.92318 Hz = 2.92318 s

-1 = 10,554 hr-1

droll = 914904.40 mm = 914.40·10-6km0.90440 m

n = 1 pulse/rev 

act

2.9231 0.90440

1

S

⋅ ⋅π

=

Sact = 29.986 kph8.3053 m/s

(ii) Compare the calculated roll speed, Sact, to the corresponding speed set point, Sref, to 

determine a value for speed error, Serror, using the following equation: 

Serror = Sact - Sref

Eq. 1066.11066.235-2 

Example:

Sact = 29.986 kph8.3053 m/s

Sref = 30.000 kph8.3000 m/s

Serror = 29.986 – 30.000 = –8.3053 – 8.3000 = 0.014 kph0053 m/s

(2) Frequency method. Use the method described in this paragraph (c)(2) only if the 

dynamometer does not have a readily available output signal for speed sensing. Install a 

single piece of tape in the shape of an arrowhead on the surface of the dynamometer roll 

near the outer edge. Put a reference mark on the deck plate in line with the arrow. Install 

a stroboscope or photo tachometer on the deck plate and direct the flash toward the tape 

on the roll. The stroboscope or photo tachometer must be calibrated according to the 

instrument manufacturer’s instructions and be capable of measuring with enough 

accuracy to perform the procedure as specified in this paragraph (c)(2). Determine the 

speed error as follows: 

(i) Set the dynamometer to speed control mode. Set the dynamometer speed to a value 

between 15 kph and the maximum speed expected during testing. Tune the stroboscope 

or photo tachometer until the signal matches the dynamometer roll speed. Record the 

frequency. Determine the roll speed, yact, using Equation 1066.11066.235-1, using the 

stroboscope or photo tachometer’s frequency for f. 

(ii) Compare the calculated roll speed, yact, to the corresponding speed set point, yref, to 

determine a value for speed error, yerror, using Equation 1066.11066.235-2. 

(d) Performance evaluation. The speed error determined in paragraph (c) of this section 

may not exceed ±0.050 mph or ±0.080 kph02 m/s. 
§1066.11066.240 Torque transducer verification and calibration. 

Calibrate torque-measurement systems as described in 40 CFR 1065.310. 

§1066.11066.245 Response time verification. 

(a) Overview. This section describes how to verify the dynamometer’s response time. 

(b) Scope and frequency. Perform this verification upon initial installation and after 

major maintenance. 

(c) Procedure. Use the dynamometer’s automated process to verify response time. 

Perform this test at two different inertia settings corresponding approximately to the 

minimum and maximum vehicle weights you expect to test. Use good engineering 

judgment to select road-load coefficients representing vehicles of the appropriate weight. 

Determine the dynamometer’s settling response time, ts, based on the point at which there 

are no measured results more than 10 % above or below the final equilibrium value, as 

illustrated in Figure 1 of this section. The observed settling response time must be less 

than 100 milliseconds for each inertia setting. 
Figure 1 of §1066.11066.245—Example of a settling response time diagram. 

ts

t

c(t)

1.1

1.0

0.9
§1066.11066.250 Base inertia verification. 

(a) Overview. This section describes how to verify the dynamometer’s base inertia. 

(b) Scope and frequency. Perform this verification upon initial installation and after 

major maintenance. 

(c) Procedure. Verify the base inertia using the following procedure: 

(1) Warm up the dynamometer according to the dynamometer manufacturer’s 

instructions. Set the dynamometer’s road-load inertia to zero and motor the rolls to 5 

mph. Apply a constant force to accelerate the roll at a nominal rate of 1 mph/s. Measure 

the elapsed time to accelerate from 10 to 40 mph, noting the corresponding speed and 

time points to the nearest 0.01 mph and 0.01 s. Also determine average force over the 

measurement interval. 

(2) Starting from a steady roll speed of 45 mph, apply a constant force to the roll to 

decelerate the roll at a nominal rate of 1 mph/s. Measure the elapsed time to decelerate 

from 40 to 10 mph, noting the corresponding speed and time points to the nearest 0.01 

mph and 0.01 s. Also determine average force over the measurement interval. 

(3) Repeat the steps in paragraphs (c)(1) and (2) of this section for a total of five sets of 

results at the nominal acceleration rate and the nominal deceleration rate. 

(4) Use good engineering judgment to select two additional acceleration and deceleration 

rates that cover the middle and upper rates expected during testing. Repeat the steps in 

paragraphs (c)(1) through (3) of this section at each of these additional acceleration and 

deceleration rates. 

(5) Determine the base inertia, Ib, for each measurement interval using the following

equation: 

b

final initial

F

I

S S

t

=

−

∆

Eq. 1066.11066.250-1 

Where: 

F = average dynamometer force over the measurement interval as measured by the 

dynamometer, in ft·lbm/s2.

Sfinal = roll surface speed at the end of the measurement interval to the nearest 0.01 mph. 

Sinitial = roll surface speed at the start of the measurement interval to the nearest 0.01 mph. 

∆t = elapsed time during the measurement interval to the nearest 0.01 s. 

Example:

F = 1.500 lbf = 48.26 ft·lbm/s2 

Sfinal = 40.00 mph = 58.67 ft/s 

Sinitial = 10.00 mph = 14.67 ft/s 

∆t = 30.00 s 

b

48.26

58.67 14.67

30.00

I =

−

Ib = 32.90 lbm 
(6) Determine the arithmetic mean value of base inertia from the five measurements at 

each acceleration and deceleration rate. Calculate these six mean values as described in 

40 CFR 1065.602(b). 

(7) Calculate the base inertia error, Iberror, for each measured base inertia, Ib, by 

comparing it to the manufacturer’s stated base inertia, Ibref, using the following equation: 

NMHC

150.3 0.990 20.5

0.990 0.020

x

⋅ −

=

−

bref bact

berror

bref

100 % I I I

I

−

= ⋅

Eq. 1066.11066.250-2 

Example:

Ibref = 32.96 lbm 

bact I = 33.01 lbm 

berror

32.96 33.01 100 %

32.96

I

−

= ⋅

Iberror = –0.15 % 

(8) Calculate the inertia error for each mean value of base inertia from paragraph (c)(6) of 

this section. Use Equation 1066.11066.265-2, substituting the mean base inertias 

associated with each acceleration and deceleration rate for the individual base inertias. 

(d) Performance evaluation. The dynamometer must meet the following specifications to 

be used for testing under this part: 

(1) The base inertia error determined under paragraph (c)(7) of this section may not 

exceed ±0.50 % relative to any individual value. 

(2) The base inertia error determined under paragraph (c)(8) of this section may not 

exceed ±0.20 % relative to any mean value. 

§1066.11066.255 Parasitic loss verification. 

(a) Overview. Verify and correct the dynamometer’s parasitic loss. This procedure 

determines the dynamometer’s internal losses that it must overcome to simulate road 

load. These losses are characterized in a parasitic loss curve that the dynamometer uses to 

apply compensating forces to maintain the desired road-load force at the roll surface. 

(b) Scope and frequency. Perform this verification upon initial installation, within 7 days 

of testing, and after major maintenance. 

(c) Procedure. Perform this verification by following the dynamometer manufacturer’s 

specifications to establish a parasitic loss curve, taking data at fixed speed intervals to 

cover the range of vehicle speeds that will occur during testing. You may zero the load 

cell at the selected speed if that improves your ability to determine the parasitic loss. 

Parasitic loss forces may never be negative. Note that the torque transducers must be 

zeroed and spanned prior to performing this procedure. 

(d) Performance evaluation. In some cases, the dynamometer automatically updates the 

parasitic loss curve for further testing. If this is not the case, compare the new parasitic 

loss curve to the original parasitic loss curve from the dynamometer manufacturer or the 
most recent parasitic loss curve you programmed into the dynamometer. You may 

reprogram the dynamometer to accept the new curve in all cases, and you must 

reprogram the dynamometer if any point on the new curve departs from the earlier curve 

by more than ±0.514.5 N (±1.0 lbf.). 

§1066.11066.260 Parasitic friction compensation evaluation. 

(a) Overview. This section describes how to verify the accuracy of the dynamometer’s 

friction compensation. 

(b) Scope and frequency. Perform this verification upon initial installation, within 7 days 

before testing, and after major maintenance. Note that this procedure relies on proper 

verification or calibration of speed and torque, as described in §§1066.11066.235 

and1066.11066.240. You must also first verify the dynamometer’s parasitic loss curve as 

specified in §1066.11066.255. 

(c) Procedure. Use the following procedure to verify the accuracy of the dynamometer’s 

friction compensation: 

(1) Warm up the dynamometer as specified by the dynamometer manufacturer. 

(2) Perform a torque verification as specified by the dynamometer manufacturer. For 

torque verifications relying on shunt procedures, if the results do not conform to 

specifications, recalibrate the dynamometer using NIST-traceable standards as 

appropriate until the dynamometer passes the torque verification. Do not change the 

dynamometer’s base inertia to pass the torque verification. 

(3) Set the dynamometer inertia to the base inertia with the road-load coefficients A, B, 

and C set to 0. Set the dynamometer to speed-control mode with a target speed of 10 

mph or a higher speed recommended by the dynamometer manufacturer. Once the speed 

stabilizes at the target speed, switch the dynamometer from speed control to torque 

control and allow the roll to coast for 60 seconds. Record the initial and final speeds and 

the corresponding start and stop times. If friction compensation is executed perfectly, 

there will be no change in speed during the measurement interval. 

(4) Calculate the friction compensation error, FCerror, using the following equation: 

( ) 2 2

error final init 2

I

FC S S

t

= ⋅ −

⋅

Eq. 1066.11066.260-5 

Where: 

I = dynamometer inertia setting, in lbf·s2/ft. 

t = duration of the measurement interval, accurate to at least 0.01 s. 

Sfinal = the roll speed corresponding to the end of the measurement interval, accurate to at 

least 0.1 mph. 

Sinit = the roll speed corresponding to the start of the measurement interval, accurate to at 

least 0.1 mph. 

Example:

I = 2000 lbm = 62.16 lbf· s2/ft 

t = 60.0 s 

Sfinal = 9.2 mph = 13.5 ft/s 

Sinit = 10.0 mph = 14.7 ft/s 
( ) 2 2

error

62.16 13.5 14.7

2 60.00

FC = ⋅ −

⋅

FCerror = –16.5 ft·lbf/s = –0.031 hp 

(5) The friction compensation error may not exceed ±0.101 hp. 

§1066.11066.265 Acceleration and deceleration verification. 

(a) Overview. This section describes how to verify the dynamometer’s ability to achieve 

targeted acceleration and deceleration rates. Paragraph (c) of this section describes how 

this verification applies when the dynamometer is programmed directly for a specific 

acceleration or deceleration rate. Paragraph (d) of this section describes how this 

verification applies when the dynamometer is programmed with a calculated force to 

achieve a targeted acceleration or deceleration rate. 

(b) Scope and frequency. Perform this verification upon initial installation and after 

major maintenance. Perform this verification upon initial installation and after major 

maintenance. 

(c) Verification of acceleration and deceleration rates. Activate the dynamometer’s 

function generator for measuring roll revolution frequency. If the dynamometer has no 

such function generator, set up a properly calibrated external function generator 

consistent with the verification described in this paragraph (c). Use the function 

generator to determine actual acceleration and deceleration rates as the dynamometer 

traverses speeds between 10 and 40 mph at various nominal acceleration and deceleration 

rates. Verify the dynamometer’s acceleration and deceleration rates as follows: 

(1) Set up start and stop frequencies specific to your dynamometer by identifying the rollrevolution frequency, f, in revolutions preper second (or Hz) corresponding to 10 mph 

and 40 mph vehicle speeds, accurate to at least four significant figures, using the 

following equation: 

THC[THC-FID]cor CH4[NMC-FID] THC[NMC-FID]cor CH4[THC-FID]

NMHC

CH4[NMC-FID] C2H6[NMC-FID] CH4[THC-FID]

x PF x RF

x

PF RFPF RF

⋅ − ⋅

=

− ⋅

roll

S n f

d π

⋅

=

⋅

Eq. 1066.11066.265-1 

Where: 

S = the target roll speed, in inches per second (corresponding to drive speeds of 10 mph 

or 40 mph). 

n = the number of pulses from the dynamometer’s roll-speed sensor per roll revolution. 

droll = roll diameter, in inches. 

(2) Program the dynamometer to accelerate the roll at a nominal rate of 1 mph/s from 10 

mph to 40 mph. Measure the elapsed time to reach the target speed, to the nearest 0.01 s. 

Repeat this measurement for a total of five runs. Determine the actual acceleration rate 

for each run, aact, using the following equation: 

final init

act

S S

a

t

−

=

Eq. 1066.11066.265-2 
Where: 

aact = acceleration rate (decelerations have negative values). 

Sfinal = the target value for the final roll speed. 

Sinit = the setpoint value for the initial roll speed. 

t = time to accelerate from Sinit to Sfinal. 

Example:

Sinal = 40 mph 

Sinit = 10 mph 

t = 30.003 s 

act

40.00 10.00

30.03

a

−

=

aact = 0.999 mph/s 

(3) Program the dynamometer to decelerate the roll at a nominal rate of 1 mph/s from 40 

mph to 10 mph. Measure the elapsed time to reach the target speed, to the nearest 0.01 s. 

Repeat this measurement for a total of five runs. Determine the actual acceleration rate, 

aact, using Equation 1066.11066.265-2 

(4) Repeat the steps in paragraphs (c)(2) and (3) of this section for additional acceleration 

and deceleration rates in 1 mph/s increments up to and including one increment above the 

maximum acceleration rate expected during testing. Average the five repeat runs to 

calculate a mean acceleration rate, act a , at each setting. 

(5) Compare each mean acceleration rate, act a , to the corresponding nominal acceleration 

rate, aref, to determine values for acceleration error, aerror, using the following equation: 

act ref

error

ref

100 % a a

a

a

−

= ⋅

Eq. 1066.11066.265-4 

Example:

act a = 0.999 mph/s 

aref = 1 mph/s 

aerror = –0.100 % 

(d) Verification of forces for controlling acceleration and deceleration. Program the 

dynamometer with a calculated force value and determine actual acceleration and 

deceleration rates as the dynamometer traverses speeds between 10 and 40 mph at 

various nominal acceleration and deceleration rates. Verify the dynamometer’s ability to 

achieve certain acceleration and deceleration rates with a given force as follows: 

(1) Calculate the force setting, F, using the following equation: 

F I a = ⋅ b

Eq. 1066.11066.265-5 

Where: 

Ib = the dynamometer manufacturer’s stated base inertia, in lbf·s2

/ft. 

a = nominal acceleration rate, in ft/s2. 
Example:

Ib = 2967 lbm = 92.217 lbf· s2

/ft

a = 1 mph/s = 1.4667 ft/s2 

F = 135.25 lbf

(2) Set the dynamometer to road-load mode and program it with a calculated force to 

accelerate the roll at a nominal rate of 1 mph/s from 10 mph to 40 mph. Measure the 

elapsed time to reach the target speed, to the nearest 0.01 s. Repeat this measurement for 

a total of five runs. Determine the actual acceleration rate, aact, for each run using 

Equation 1066.11066.265-2. Repeat this step to determine measured “negative 

acceleration” rates using a calculated force to decelerate the roll at a nominal rate of 1 

mph/s from 40 mph to 10 mph. Average the five repeat runs to calculate a mean 

acceleration rate, act a , at each setting. 

(3) Repeat the steps in paragraph (d)(2) of this section for additional acceleration and 

deceleration rates as specified in paragraph (c)(4) of this section. 

(4) Compare each mean acceleration rate, act a , to the corresponding nominal acceleration 

rate, aref, to determine values for acceleration error, aerror, using Equation 

1066.11066.265-4 

(e) Performance evaluation. The acceleration error from paragraphs (c)(5) and (d)(4) of 

this section may not exceed ±1.0 %. 

§1066.11066.270 Unloaded coastdown verification. 

(a) Overview. Use force measurements to verify the dynamometer’s settings based on 

coastdown procedures. 

(b) Scope and frequency. Perform this verification upon initial installation, within 7 days 

of testing, and after major maintenance. 

(c) Procedure. This procedure verifies the dynamometer’s settings derived from 

coastdowns testing. For dynamometers that have an automated process for this 

procedure, perform this evaluation by setting the initial speed, and final speed, and the

inertial, and road-load coefficients as required for each test, using good engineering 

judgment to ensure that these values properly represent in-use operation. Use the 

following procedure if your dynamometer does not perform this verification with have an 

automated process: 

(1) Warm up the dynamometer as specified by the dynamometer manufacturer. 

(2) With the dynamometer in coastdown mode, set the dynamometer inertia for the 

smallest vehicle weight that you expect to test and set A, B, and C road-load coefficients 

to values typical of those used during testing. Program the dynamometer to operate at 10 

mph. Perform a coastdown two times at this speed setting. Repeat these coastdown steps 

in 10 mph increments up to and including one increment above the maximum speed 

expected during testing. You may stop the verification before reaching 0 mph, with any 

appropriate adjustments in calculating the results.

(3) Repeat the steps in paragraph (c)(2) of this section with the dynamometer inertia set 

for the largest vehicle weight that you expect to test. 

(4) Determine the average coastdown force, F, for each speed and inertia setting using the 

following equation: 
si I S F

t

⋅

=

Eq. 1066.11066.270-1 

Where: 

F = the average force measured during the coastdown for each speed and inertia setting, 

expressed in lbf· s2/ft and rounded to four significant figures.

I = the dynamometer’s inertia setting, in lbf· s2/ft. 

Ssi = the speed setting at the start of the coastdown, expressed in ft/s and rounded to four 

significant figures. 

t = coastdown time for each speed and inertia setting, accurate to at least 0.01 s. 

Example:

I = 2000 lbm = 65.17 lbf · s2

/ft

Ssi = 10 mph = 14.66 ft/s 

t = 5.00 s 

65.17 14.66

5.00

F

⋅

=

F = 191 lbf 

(5) Calculate the target value of coastdown force, Fref, based on the applicable 

dynamometer parameters for each speed and inertia setting. 

(6) Compare the mean value of the coastdown force measured for each speed and inertia 

setting, Fact , to the corresponding Fref to determine values for coastdown force error, 

Ferror, using the following equation: 

act ref

error

ref

100 % F F F

F

−

= ⋅

Eq. 1066.11066.270-2 

Example:

Fref = 192 lbf 

Fact = 191 lbf 

error

191 192 100 %

192

F

−

= ⋅

Ferror = –0.5 % 

(7) Calculate The maximum allowable error, Ferrormax, for all speed and inertia settings as 

follows:

(i) For dynamometers used to test light-duty vehicles and heavy-duty vehicles with 

GVWR at or below 14,000 lbs, Ferrormax = (2.2 lbf/Fref)·100 %].

(ii) For heavy-dutyis calculated from the following formula, except that Ferrormax for

vehicles with GVWR above 14,000 lbs, Ferrormax = Max [± may be up to ±1.0 % or (2.2 

lbf/Fref)·100 %].%:

Ferrormax (%) = (2.2 lbf/Fref)·100
§1066.11066.280 Driver’s aid. 

Use good engineering judgment to provide a driver’s aid that facilitates compliance with 

the requirements of §1066.31066.430. 

Subpart CDD—Coastdown 

§1066.21066.301 Overview of coastdown procedures. 

(a) The coastdown procedures described in this subpart are used to determine the load 

coefficients (A, B, and C) for the simulated road-load equation in §1066.11066.210(d)(3). 

(b) The general procedure for performing coastdown tests and calculating load 

coefficients is described in SAE J1263 and SAE J2263 (incorporated by reference in 

§1066.710). This subpart specifies certain deviations from SAE J2263those procedures

for certain applications. 

(c) Use good engineering judgment for all aspects of coastdown testing. For example, 

minimize the effects of grade by performing coastdown testing on reasonably level 

surfaces and determining coefficients based on average values from vehicle operation in 

opposite directions over the course. 

 

§1066.21066.310 Coastdown procedures for heavy-duty vehicles. 

This section describes coastdown procedures that are unique to heavy-duty motor 

vehicles. Note as specified in the standard setting parts, this section does not apply for 

certain heavy-duty vehicles, such as those regulated under 40 CFR part 86, Subpart S.

(a) Determine load coefficients by performing a minimum of 2016 valid coastdown runs 

(108 in each direction). 

(b) Follow the provisions of Sections 1 through 9 of SAE J1263, and SAE J2263 

(incorporated by reference in §1066.710), except as described in this paragraph (b). The 

terms and variables identified in this paragraph (b) have the meaning given in SAE J1263 

or J2263 unless specified otherwise. 

(1) You are The test condition specifications of SAE J1263 apply except as follows for 

wind and road conditions:

(i) We recommend that you do not requiredperform coastdown testing on days for which 

winds are forecast to exceed 6.0 mph.

(ii) The grade of the test track or road must not be excessive (considering factors such 

asroad safety standards and effects on the coastdown results). Road conditions should 

follow Section 7.4 of SAE J1263, except that road grade may exceed 0.5%. If road grade 

is greater than 0.02% over the length of the test surface, then the road grade as a function 

of distance along the length of the test surface must be incorporated in the analysis. To 

calculate the force due to grade use Section 11.5 of SAE J2263.

(2) You must reach thea top speed specified in Section 9.3 of SAE J2263, as long as your 

top of greater than 70 mph such that data collection of the coastdown can start at or above 

70 mph. Data collection must occur through a minimum speed for at or below 15 mph. 

Data analysis for valid coastdown runs must include a maximum speed of 70 mph 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.

(ii) The anemometer must have had its outputs recorded at a wind speed of 0.0 mph 

within 24 hours before each run is no lower than 100 km/h (62.2 mph).coastdown test in 

which it is used.

((iii) Record the location of the anemometer using a GPS measurement device adjacent to 

the test surface (approximately) at the midway distance along the test surface used for 

coastdowns.

(iv) Position the anemometer such that it will be at least 2).5 but not more than 3.0 

vehicle widths from the test vehicle’s centerline as the test vehicle passes the location of 

that anemometer.

(v) Mount the anemometer at a height that is within 6 inches of half the test vehicle’s 

maximum height.

(vi) Place the anemometer at least 50 feet from the nearest tree and at least 25 feet from 

the nearest bush (or equivalent roadside features).

(vii) The height of the grass surrounding the stationary anemometer may not exceed 10% 

of the anemometer’s mounted height, within a radius equal to the anemometer’s mounted 

height.

(4) You may split runs as per Section 9.3.1 of SAE J2263 allows split runs, but we 

recommend whole runs. If you use split runsa run, analyze themeach portion separately,

but count them togetherthe split runs as one run with respect to the minimum number of 

runs required. 

(35) You may perform consecutive runs in a single direction, followed by consecutive 

runs in the opposite direction, consistent with good engineering judgment. Harmonize 

starting and stopping points to the extent practicable to allow runs to be paired. 

(4) Section 12.1 of SAE J2263 allows determination of calibration coefficients from 

calibration runs conducted at a constant 50 mph in each road direction. 

(i) We recommend(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.

(7) Determine drag area, CDA, as follows instead of using the procedure specified in SAE 

J1263, Section 10:

(i) Measure vehicle speed at fixed intervals over the coastdown run (generally at 10 Hz), 

including speeds at or above 15 mph and at or below 70 mph. Establish the height or

altitude corresponding to each interval as described in SAE J2263 if you need to 

incorporate the effects of road grade.

(ii) Calculate the vehicle’s effective mass, Me, in kg by adding 56.7 kg to the vehicle 

mass for each tire making road contact. This accounts for the rotational inertia of the 

wheels and tires.

(iii) Calculate the road-load force for each measurement interval, Fi, using the following 

equation to correct relative wind speed (Sr) in calibration runs: :

i i 1

i e

v v F M

t

− − = − ⋅

∆

Eq. 1066.21066.310-1 

Field Code Changed
(ii) We recommend usingWhere:

v = Vehicle speed at the beginning and end of the measurement interval. Let v0 = 0.

∆t = Elapsed time over the measurement interval.

(iv) Plot the data from all the coastdown runs on a single plot of Fi vs. vi

2

 to determine the 

slope correlation, D, based on the following equation to correct yaw angle (Y) in 

coastdowns: :

25

i meas,i meas,dir,i

dir i 1 i,dir

1 1

2

Y Y Y

n =

 

= −  

  ∑ ∑ 2

i e m i

h

F M g A D v

s

∆

− ⋅ ⋅ = + ⋅

∆

Eq. 1066.21066.310-2 

(5) Use Where:

g = Gravitational acceleration = 9.81 m/s2.

∆h = Change in height or altitude over the measurement interval, in m. Assume ∆h = 0 if 

you are not correcting for grade. 

∆s = Distance the vehicle travels down the road during the measurement interval, in m.

Am = the calculated value of the y-intercept based on the curve-fit.

(v) Calculate drag area, CDA, in m2 using the following equation of motion instead of the 

equation specified in SAE J2263: 

adj

D

2 D

C A

ρ

⋅

=

Eq. 1066.21066.310-3 

(i) Determine Am, Da, and E using a mixed model technique, with the run being the 

random effect.

(iiWhere:

ρ = Air density at reference conditions = 1.17 kg/m3.

adj

B

98.21

293

T

D D

P

   

= ⋅ ⋅        

Eq. 1066.310-4

T = Average ambient temperature during testing, in K.

PB = Average ambient pressuring during the test, in kPa.

(8) Determine the A, B, and C coefficients identified in §1066.11066.210 as follows: 

A= Am

B= 0 

C= Da Dadj

(iii) Consistent with good engineering judgment, set E equal to zero if wind direction 

effects are not statistically significant. Use the following simplified equation of motion if 

wind direction effects are not statistically significant and grade effects are negligible:

Field Code Changed
2

e m a r ·

S

M A D S

t

∆

− = +

∆

 

Eq. 1066.21066.310-4

Subpart DEE—Vehicle Preparation and Running a Test 

§1066.31066.401 Overview. 

(a) Use the procedures detailed in this subpart to measure vehicle emissions over a 

specified drive schedule. This subpart describes how to: 

(1) Determine road-load power, test weight, and inertia class. 

(2) Prepare the vehicle, equipment, and measurement instruments for an emission test. 

(3) Perform pre-test procedures to verify proper operation of certain equipment and 

analyzers and to prepare them for testing. 

(4) Record pre-test data. 

(5) Sample emissions. 

(6) Record post-test data. 

(7) Perform post-test procedures to verify proper operation of certain equipment and 

analyzers. 

(8) Weigh PM samples. 

(b) An emission test generally consists of measuring emissions and other parameters 

while a vehicle follows the drive schedules specified in the standard-setting part. There 

are two general types of test cycles: 

(1) Transient cycles. Transient test cycles are typically specified in the standard-setting 

part as a second-by-second sequence of vehicle speed commands. Operate a vehicle over 

a transient cycle such that the speed follows the target values. Proportionally sample 

emissions and other parameters and use the calculations in 40 CFR part 86, subpart B, or 

40 CFR part 1065, subpart G, to calculate emissions. The standard-setting part may 

specify three types of transient testing based on the approach to starting the measurement, 

as follows: 

(i) A cold-start transient cycle where you start to measure emissions just before starting 

an engine that has not been warmed up. 

(ii) A hot-start transient cycle where you start to measure emissions just before starting a 

warmed-up engine. 

(iii) A hot running transient cycle where you start to measure emissions after an engine is 

started, warmed up, and running. 

(2) Cruise cycles. Cruise test cycles are typically specified in the standard-setting part as 

a discrete operating point that has a single speed command. 

(i) Start a cruise cycle as a hot running test, where you start to measure emissions after 

the engine is started and warmed up and the vehicle is running at the target test speed. 

(ii) Sample emissions and other parameters for the cruise cycle in the same manner as a 

transient cycle, with the exception that the reference speed value is constant. Record 

instantaneous and mean speed values over the cycle.

§1066.31066.404 Road load power and test weight determination.
To determine road load power and test weight, follow SAE J2263 and SAE J2264 

(incorporated by reference in §1066.710), with the following exceptions:

(a) Test weight. The rotational inertia of drive-axle and nondrive-axle components that 

rotate with the wheels is expressed as additional “linear” mass. For Class 7 combination 

and Class 8 heavy-duty vehicles, without dual drive tires (or other driveline components 

which are likely to increase real rotational inertia to greater than 1.5% per axle) and if the 

actual effective mass of rotating components is unknown, the effective mass of all 

rotating components may be estimated as 4.0% of the vehicle test mass. 

(b) [Reserved]

§1066.31066§1066.407 Vehicle preparation and preconditioning. 

This section describes steps to take before measuring exhaust emissions for those 

vehicles that are subject to evaporative or refueling emission tests as specified in subpart 

F of thisthe standard setting part. Other preliminary procedures may apply as specified in 

the standard-setting part. 

(a) Prepare the vehicle for testing as described in 40 CFR 86.131-00. 

(b) If testing will include measurement of refueling emissions, perform the vehicle 

preconditioning steps as described in 40 CFR 86.153-98. Otherwise, perform the vehicle 

preconditioning steps as described in 40 CFR 86.132-00. 

§1066.31066.410 Dynamometer test procedure. 

(a) Dynamometer testing may consist of multiple drive cycles with both cold-start and 

hot-start portions, including prescribed soak times before each test phase. See the 

standard-setting part for test cycles and soak times for the appropriate vehicle category. 

A test phase consists of engine startup (with accessories operated according to the 

standard-setting part), operation over the drive cycle, and engine shutdown. 

(b) During dynamometer operation, position a road-speed modulated cooling fan that 

appropriately directs cooling air to the vehicle. This generally requires squarely 

positioning the fan within 30 centimeters of the front of the vehicle and directing the 

airflow to the vehicle’s radiator. 

(1) For light-duty vehicles and for heavy-duty vehicles with a GVWR at or below 14,000 

lbs, you may use either of the following cooling fan configurations:

(i) Use a fixed-speed cooling fan to appropriately direct cooling air to the vehicle in an 

appropriate manner with the engine compartment cover open. The fan capacity may not 

exceed 2.50 m3/s. If you determine that additional cooling is needed to provide a 

representative testproperly represent in-use operation, use good engineering judgment to 

increase fanthe fan’s capacity or supplyuse additional fans, subject to theour approval of 

the Administrator. 

(2) For heavy-duty vehicles with GVWR above 14,000 lbs, uUse(ii) Use a road-speed 

modulated cooling fan system that achieves a linear speed of cooling air at the blower 

outlet that is within ±3.0 mph (±1.3 m/s) of the corresponding roll speed when vehicle 

speeds are between 5 toand 30 mph, (2.2 to 13.4 m/s), and within ±6.5 mph (±2.9 m/s) of 

the corresponding roll speed at higher vehicle speeds. The fan must provide no cooling 

air for vehicle speeds below 5 mph, unless we approve your request to provide cooling 

during low-speed operation based on a demonstration that this is appropriate to simulate 
cooling for in-use vehicles. We recommend that the cooling fan have a minimum 

opening of 0.2 m2 and a minimum width of 0.8 m.

(2) For vehicles with GVWR above 14,000 lbs, use a road-speed modulated fan system 

that achieves a linear speed of cooling air at the blower outlet that is within ±3.0 mph 

(±1.3 m/s) of the corresponding roll speed when vehicle speeds are between 5 and 30 

mph (2.2 to 13.4 m/s), and within ±10 mph (±4.5 m/s) of the corresponding roll speed at 

higher vehicle speeds. The fan must provide no cooling air for vehicle speeds below 5 

mph, unless we approve your request to provide cooling during low-speed operation 

based on a demonstration that this is appropriate to simulate the cooling experienced by 

in-use vehicles. We recommend that the cooling fan have a minimum opening of 2.75 

m

2

, a minimum flow rate of 3,600 m3/min at 50 mph, and that it maintain a minimum 

velocityspeed profile across the duct, in the free stream flow, of ±15 % of the target flow 

rate. 

(3) If the cooling specifications in this paragraph (b) are impractical for special vehicle 

designs, such as vehicles with rear-mounted engines, you may arrange for an alternative 

fan configuration, subject to approval of the thatAdministrator that allows for proper 

simulation of vehicle cooling during in-use operation, subject to our approval. 

(c) Record the vehicle’s speed trace based on the time and speed data from the 

dynamometer. Record speed to at least the nearest 0.01 m/s or 0.1 mph and time to at 

least the nearest 0.1 s. 

(d) You may perform practice runs to for operating the vehicle and the dynamometer 

controls to meet the driving tolerances specified in §1066.31066.430 or adjust the 

emission sampling equipment. Verify that the accelerator pedal allows for enough 

control to closely follow the prescribed driving schedule. You may not measure 

emissions during a practice run. 

(e) Inflate the drive wheel tires according to the vehicle manufacturer’s specifications. 

The drive wheels’ tire pressure must be the same for dynamometer operation and for 

coastdown procedures for determining road-load coefficients. Report these tire pressure 

values with the test results. 

(f) For heavy-duty vehicles with GVWR above 14,000 lbs, you must use a vehicle pull 

down mechanism that allows simulation of the actual normal forces that the tire and 

dynamometer roll interface would see if a loaded vehicle were actually being tested. Use 

of this mechanism will ensure that wheel slip does not occur when trying to accelerate the 

loaded vehicle. 

Warm up the dynamometer as recommended by the dynamometer manufacturer.

(g) Following the test, determine the actual driving distance by counting the number of 

dynamometer roll or shaft revolutions, or by integrating speed over the course of testing 

from a high-resolution encoder system.

(h) Use good engineering judgment to when testing vehicles in four-wheel drive and or 

all-wheel drive vehiclesmodemode. This may involve testing on a dynamometer with a

separate dynamometer roll for each drive axle. This may also involve operation on a 

single roll, which would may require disengaging the second set of drive wheels, either 

with a switch available to the driver or by some other means; however, operating such a 

vehicle on a single roll may occur only if this does not decrease emissions or energy 

consumption relative to normal in-use operation. Alternatively, for heavy-duty motor 
vehicles, up to two driven axles may use a single drive roll, as described in

§1066.210(d)(2). 

(h) Warm up the dynamometer as recommended by the dynamometer manufacturer. 

(i) Following the test, determine the actual driving distance by counting the number of 

dynamometer roll or shaft revolutions, or by integrating speed over the course of testing 

from a high-resolution encoder system. 

§1066.31066.420 Pre-test verification procedures and pre-test data collection.

(a) Follow the procedures for PM sample preconditioning and tare weighing as described 

in 40 CFR 1065.590 if your engine must comply with a PM standard. 

(b) Unless the standard-setting part specifies different tolerances, verify at some point 

before the test that ambient conditions are within the tolerances specified in this 

paragraph (b). For purposes of this paragraph (b), “before the test” means any time from 

a point just prior to engine starting (excluding engine restarts) to the point at which 

emission sampling begins. 

(1) Ambient temperature must be (20 to 30) °C. See §1066.31066.430(m) for 

circumstances under which ambient temperatures must remain within this range during 

the test. 

(2) Atmospheric pressure must be (80.000 to 103.325) kPa. You are not required to 

verify atmospheric pressure prior to a hot-start test interval for testing that also includes a 

cold start. 

(3) Dilution air conditions must meet the specifications in 40 CFR 1065.140, except in 

cases where you preheat your CVS before a cold-start test. We recommend verifying 

dilution air conditions just before starting each test phase. 

(c) You may test vehicles at any intake-air humidity and we may test vehicles at any 

intake-air humidity..

(d) You may perform a final calibration of the proportional-flow control systems, which 

may include performing practice runs. 

(e) You may perform the following recommended procedure to precondition sampling 

systems: 

(1) Operate the vehicle over the test cycle. 

(2) Operate any dilution systems at their expected flow rates. Prevent aqueous 

condensation in the dilution systems. 

(3) Operate any PM sampling systems at their expected flow rates. 

(4) Sample PM for at least 10 min using any sample media. You may change sample 

media during preconditioning. You must discard preconditioning samples without 

weighing them. 

(5) You may purge any gaseous sampling systems during preconditioning. 

(6) You may conduct calibrations or verifications on any idle equipment or analyzers 

during preconditioning. 

(7) Proceed with the test sequence described in §1066.31066.430. 

(f) Verify the amount of nonmethane hydrocarbon (or equivalent) contamination in the 

exhaust and background HC sampling systems within 8 hours before the start of the first 

test drive cycle for each individual vehicle tested as described in 40 CFR 

1065.515520(g). 
§1066.31066.425 Engine starting and restarting. 

(a) Start the vehicle’s engine as follows: 

(1) At the beginning of the test cycle, start the engine according to the procedure you 

describe in your owners manual. In the case of hybrid vehicles, this would generally 

involve activating vehicle systems such that the engine will start when the vehicle’s 

control algorithms determine that the engine should provide power instead of or in 

addition to power from the rechargeable energy storage system (RESS). Unless we 

specify otherwise, engine starting throughout this part generally refers to this step of 

activating the system on hybrid vehicles, whether or not that causes the engine to start 

running.

(2) Place the transmission in gear as described by the test cycle in the standard-setting 

part. During idle operation, you may apply the brakes if necessary to keep the drive 

wheels from turning. 

(b) If the vehicle does not start after your recommended maximum cranking time, wait 

and restart cranking according to your recommended practice. If you don’t recommend 

such a cranking procedure, stop cranking after 10 seconds, wait for 10 seconds, then start 

cranking gain for up to 10 seconds. You may repeat this for up to three start attempts. If 

the vehicle does not start after three attempts, you must determine and record the reason 

for failure to start. Shut off sampling systems and either turn the CVS off, or disconnect 

the exhaust tube from the tailpipe during the diagnostic period. Reschedule the vehicle 

for testing from a cold start. 

(c) Repeat the recommended starting procedure if the engine has a “false start”. 

(d) Take the following steps if the engine stalls: 

(1) If the engine stalls during an idle period, restart the engine immediately and continue 

the test. If you cannot restart the engine soon enough to allow the vehicle to follow the 

next acceleration, stop the driving schedule indicator and reactivate it when the vehicle 

restarts. 

(2) If the engine stalls during operation other than idle, stop the driving schedule 

indicator, restart the engine, accelerate to the speed required at that point in the driving 

schedule, reactivate the driving schedule indicator, and continue the test. 

(3) Void the test if the vehicle will not restart within one minute. If this happens, remove 

the vehicle from the dynamometer, take corrective action, and reschedule the vehicle for 

testing. Record the reason for the malfunction (if determined) and any corrective action. 

See the standard-setting part for instructions about reporting these malfunctions. 

§1066.31066.430 Performing emission tests.

The overall test consists of prescribed sequences of fueling, parking, and 

operatingdriving at specified test conditions. 

(a) Vehicles are tested for criteria pollutants and greenhouse gas emissions as described 

in the standard-setting part. 

(b) Take the following steps before emission sampling begins: 

(1) For batch sampling, connect clean storage media, such as evacuated bags or tareweighed filters. 

(2) Start all measurement instruments according to the instrument manufacturer’s 

instructions and using good engineering judgment. 

(3) Start dilution systems, sample pumps, and the data-collection system. 
(4) Pre-heat or pre-cool heat exchangers in the sampling system to within their operating 

temperature tolerances for a test. 

(5) Allow heated or cooled components such as sample lines, filters, chillers, and pumps 

to stabilize at their operating temperatures. 

(6) Verify that there are no significant vacuum-side leaks according to 40 CFR 1065.345. 

(7) Adjust the sample flow rates to desired levels, using bypass flow, if desired. 

(8) Zero or re-zero any electronic integrating devices, before the start of any test interval. 

(9) Select gas analyzer ranges. You may automatically or manually switch gas analyzer 

ranges during a test only if switching is performed by changing the span over which the 

digital resolution of the instrument is applied. During a test you may not switch the gains 

of an analyzer’s analog operational amplifier(s). 

(10) Zero and span all continuous gas analyzers using NIST-traceable gases that meet the 

specifications of 40 CFR 1065.750. Span FID analyzers on a carbon number basis of one 

(1), C1.). For example, if you use a C3H8 span gas of concentration 200 μmol/mol, span 

the FID to respond with a value of 600 μmol/mol. Span FID analyzers consistent with 

the determination of their respective response factors, RF, and penetration fractions, PF, 

according to 40 CFR 1065.365. 

(11) We recommend that you verify gas analyzer responses after zeroing and spanning by 

sampling a calibration gas that has a concentration near one-half of the span gas 

concentration. Based on the results and good engineering judgment, you may decide 

whether or not to re-zero, re-span, or re-calibrate a gas analyzer before starting a test. 

(12) If you correct for dilution air background concentrations of associated engine 

exhaust constituents, start measuring (i.e. sampling) and recording background 

concentrations. 

(13) Turn on cooling fans immediately prior to the start ofbefore starting the test. 

(c) Operate vehicles during testing as follows: 

(1) Where we do not give specific instructions, operate the vehicle according to your 

recommendations in the owners manual, unless those recommendations are 

unrepresentative of what may reasonably be expected for in-use operation. 

(2) If vehicles have features that preclude dynamometer testing, modify these features as 

necessary to allow testing, consistent with good engineering judgment. 

(3) Operate vehicles during idle as follows: 

(i) For a vehicle with an automatic transmission, operate at idle with the transmission in 

“Drive” with the wheels braked, except that you may shift to “Neutral” for the first idle 

period and for any idle period longer than one minute. If you put the vehicle in “Neutral” 

during an idle, you must shift the vehicle into “Drive” with the wheels braked at least 5 

seconds before the end of the idle period. 

(ii) For a vehiclevehicles with a manual transmission, operate at idle with the 

transmission in gear with the clutch disengaged, except that you may shift to “Neutral” 

with the clutch disengaged for the first idle period and for any idle period longer than one 

minute. If you put the vehicle in “Neutral” during idle, you must shift to first gear with 

the clutch disengaged at least 5 seconds before the end of the idle period. 

(4) Operate the vehicle with the appropriate accelerator pedal movement necessary to 

achieve the speed versus time relationship prescribed by the driving schedule. Both 

theAvoid smoothing of speed variations and excessive accelerator pedal perturbations

must be avoided. 
(45)5) Operate the vehicle shall be operated smoothly, following representative shift 

speeds and procedures. For manual transmissions, the operator shall release the 

accelerator pedal during each shift and accomplish the shift with minimum time. If the 

vehicle cannot accelerate at the specified rate, operate it at maximum available power 

until the vehicle speed reaches the value prescribed for that time in the driving schedule. 

(566) Decelerate without changing gears, using the brakes or accelerator pedal as 

necessary to maintain the desired speed. Keep the clutch engaged on manual transmission 

vehicles and do not change gears after the end of the acceleration event. Depress manual 

transmission clutches when the speed drops below 6.7 m/s (15 mph (24.1 km/h), when 

engine roughness is evident, or when engine stalling is imminent. 

(677) For test vehicles equipped with manual transmissions, shift gears in a way that 

represents reasonable shift patterns for in-use operation, considering vehicle speed, 

engine speed, and any other relevant variables. You may recommend a shift schedule in 

your owners manual that differs from your shift schedule during testing as long as you 

include both shift schedules in your application for certification. In this case, we may use 

the shift schedule you describe in your owners manual. 

(d) See the standard-setting part for drive schedules. These are defined by a smooth trace 

drawn through the specified speed vs. time sequence. 

(e) The driver must attempt to follow the target schedule as closely as possible, consistent 

with the specifications in paragraph (b) of this section. Instantaneous speeds must stay 

within the following tolerances: 

(1) The upper limit is 21.0 m/s (2 mph) higher than the highest point on the trace within 

1.0 s of the given point in time. 

(2) The lower limit is 1.0 m/s (2.0 mph) lower than the lowest point on the trace within 

1.0 seconds of the given time. 

(3) The same limits apply for for vehicle preconditioning, except that the upper and lower 

limits for speed values are ±42.0 m/s (±4 mph.).

(4) Void the test if you do not maintain speed values as specified in this paragraph (e)(4). 

Speed variations (such as may occur during gear changes or braking spikes) may occur as 

follows, provided that such variations are clearly documented, including the time and 

speed values and the reason for the deviation: 

(i) Speed variations greater than the specified limits are acceptable for up to 2.0 seconds 

on any occasion. 

(ii) For vehicle preconditioning, up to three additional occurrences of speed variations

outside the specified limits are acceptable for up to 15 seconds on any occasion. 

(iii) For vehicles that are not able to maintain acceleration as specified in paragraph 

(b)(4c)(5) of this section, do not count the insufficient acceleration as being outside the 

specified limits. 

(f) Figure 1 and Figure 2 of this section show the range of acceptable speed tolerances for 

typical points during testing. Figure 1 of this section is typical of portions of the speed 

curve that are increasing or decreasing throughout the 2-second time interval. Figure 2 of 

this section is typical of portions of the speed curve that include a maximum or minimum 

value. 
Figure 1 of §1066.31066.430—Example of the allowable ranges for the driver’s trace. 

Figure 2 of §1066.31066.430—Example of the allowable ranges for the driver’s trace. 

1.0 s

Time

Speed

Allowable 

Range 

1.0

m/s

1.0

m/s

1.0 s
(g) Start testing as follows: 

(1) If a vehicle is already running and warmed up, and starting is not part of the test 

cycle, performoperate the following for the following types ofvehicle as follows:

1.0 s 

Time

Speed

Allowable 

Range 

1.0

m/s

1.0

m/s

1.0 s 
(i) For transient test cycles:

(i) Transient test cycles. , control vehicle speeds to follow a drive schedule consisting of a 

series of idles, accelerations, cruises, and decelerations. 

(ii) For cruise test cycles. , control the vehicle operation to match the speed of the first 

phase of the test cycle. Follow the instructions in the standard-setting part to determine 

how long to stabilize the vehicle during each phase, how long to sample emissions at 

each phase, and how to transition between phases. 

(2) If engine starting is part of the test cycle, initiate data logging, sampling of exhaust 

gases, and integrating measured values before starting the engine. Initiate the driver’s 

trace when the engine starts. 

(h) At the end of each test interval, continue to operate all sampling and dilution systems 

to allow the response times to elapse. Then stop all sampling and recording, including 

the recording of background samples. Finally, stop any integrating devices and indicate 

the end of the duty cycle in the recorded data. 

(i) Shut down the vehicle if it is part of the test cycle or if testing is complete. 

(j) If testing involves engine shutdown followed by another test phase, start a timer for 

the vehicle soak when the engine shuts down. 

(k) Take the following steps after emission sampling is complete: 

(1) For any proportional batch sample, such as a bag sample or PM sample, verify that 

proportional sampling was maintained according to 40 CFR 1065.545. Void any samples 

that did not maintain proportional sampling according to specifications. 

(2) Place any used PM samples into covered or sealed containers and return them to the 

PM-stabilization environment. Follow the PM sample post-conditioning and total 

weighing procedures in 40 CFR 1065.595. 

(3) As soon as practical after the test cycle is complete, or optionally during the soak 

period if practical, perform the following: 

(i) Drift check all continuous gas analyzers and zero and span all batch gas analyzers no 

later than 30 minutes after the test cycle is complete, or during the soak period if 

practical. 

(ii) Analyze any conventional gaseous batch samples no later than 30 minutes after a test 

phase is complete, or during the soak period if practical. Analyze nonconventional 

gaseous batch samples, such as NMHCE sampling with ethanol, as soon as practicable 

using good engineering judgment.

(iii) Analyze background samples no later than 60 minutes after the test cycle is 

complete. 

(iv) Analyze non-conventional gaseous batch samples, such as ethanol (NMHCE) 

requiring off-line analysis, such as ethanol, no later than 30 minutes after the test cycle is 

completeas soon as practical using good engineering judgment.

(4) After quantifying exhaust gases, verify drift as follows: 

(i) For batch and continuous gas analyzers, record the mean analyzer value after 

stabilizing a zero gas to the analyzer. Stabilization may include time to purge the 

analyzer of any sample gas, plus any additional time to account for analyzer response. 

(ii) Record the mean analyzer value after stabilizing the span gas to the analyzer. 

Stabilization may include time to purge the analyzer of any sample gas, plus any 

additional time to account for analyzer response. 

(iii) Use these data to validate and correct for drift as described in 40 CFR 1065.550. 
(l) [Reserved] 

(m) Measure and record ambient temperature and pressure. Also measure humidity, as 

required, such as for correcting NOx emissions. For testing vehicles with the following 

engines, you must record ambient temperature continuously to verify that it remains 

within the temperature range specified in §1066.31066.420(b)(1) throughout the test: 

(1) Air-cooled engines. 

(2) Engines equipped with emission control devices that sense and respond to ambient 

temperature. 

(3) Any other engine for which good engineering judgment indicates that this is 

necessary to remain consistent with 40 CFR 1065.10(c)(1). 

Subpart EFF—Hybrids 

§1066.401 501 Overview. 

To determine State of Charge, correct fuel economy or emission results for Net Energy 

Change, and State of Charge correction for emission results, follow SAE J1711 and of the 

RESS, use the procedures specified for charge-sustaining operation in SAE J2711 

(incorporated by reference in §1066.710). 

Subpart F—[Reserved]

Subpart G—Calculations 

§1066.601 Overview. 

(a) This subpart describes how to– 

(1) Use the signals recorded before, during, and after an emission test to calculate 

distance-specific emissions of each regulated pollutant. 

(2) Perform calculations for calibrations and performance checks. 

(3) Determine statistical values. 

(b) You may use data from multiple systems to calculate test results for a single emission 

test, consistent with good engineering judgment. You may also make multiple 

measurements from a single batch sample, such as multiple weighing of a PM filter or 

multiple readings from a bag sample. You may not use test results from multiple 

emission tests to report emissions. We allow weighted means where appropriate. You 

may discard statistical outliers, but you must report all results. 

§1066.610 Mass-based and molar-based exhaust emission calculations. 

(a) General. Calculate your total mass of emissions over a test cycle as specified in 40 

CFR 86.144-94 or 40 CFR part 1065, subpart G. 

(b) Composite emissions over multiple test cycles. (b) For composite emission 

calculations over multiple test phases and corresponding weighting factors, see the 

standard-setting part. 

Subpart H—Definitions and Other Reference Material 
§1066.701 Definitions. 

The definitions in this section apply to this part. The definitions apply to all subparts 

unless we note otherwise. Other terms have the meaning given in 40 CFR part 1065. 

The definitions follow: 

 Base inertia means a value expressed in mass units to represent the rotational inertia 

of the rotating dynamometer components between the vehicle driving tires and the 

dynamometer torque-measuring device, as specified in §1066.11066.250. 

Driving schedule means a series of vehicle speeds that a vehicle must follow 

during a test. Driving schedules are specified in the standard-setting part. A driving 

schedule may consist of multiple test phases. 

Duty cycle means a set of weighting factors and the corresponding test cycles, 

where the weighting factors are used to combine the results of multiple test phases into a 

composite result. 

Road-load coefficients means sets of A, B, and C road-load force coefficients that 

are used in the dynamometer road-load simulation, where road-load force at speed S

equals A + B·S + C·S

2

. 

 Test phase means a duration over which a vehicle’s emission rates are determined for 

comparison to an emission standard. For example, the standard-setting part may specify 

a complete duty cycle as a cold-start test phase and a hot-start test phase. In cases where 

multiple test phases occur over a duty cycle, the standard-setting part may specify 

additional calculations that weight and combine results to arrive at composite values for 

comparison against the applicable standards. 

 Test weight has the meaning given in the standard-setting part. 

 Unloaded coastdown means a dynamometer coastdown run with the vehicle wheels 

off the roll surface. 

§1066.705 Symbols, abbreviations, acronyms, and units of measure. 

The procedures in this part generally follow either the International System of Units (SI) 

or the United States customary units, as detailed in NIST Special Publication 811, 1995 

Edition, “Guide for the Use of the International System, of Units (SI),” which we 

incorporate by reference in §1066.710. See 40 CFR 1065.25 20 for specific provisions 

related to these conventions. This section summarizes the way we use symbols, units of 

measure, and other abbreviations. 

(a) Symbols for quantities. This part uses the following symbols and units of measure for 

various quantities: 

Symbol Quantity Unit Unit symbol BaseUnit in terms of

SI base units 

∆a

symbol prefix to denote an 

interval acceleration 

miles per hourfeet per second 

squared or meters per second 

squared

mphft/s2 or m/s2 m·s

-2

% percent 0.01 % 10-2

d diameter Inchesmeters inm m

F force pound force or newton lbf or N kg·s

-2

f frequency hertz Hz s-1

I inertia pound mass or kilogram lbm or kg kg

i indexing variable 

M mass pound mass or kilogram lbm or kg kg

N total number in series 

n total number of pulses in a series 

Formatted Table

Formatted Table

Formatted Table

Formatted Table
R dynamometer roll revolutions revolutions per minute rpm 2·π·60-1

· m·m-1·s-1

RL road-load coefficient horsepower or kilowatt hp or kW 103·m

2

·kg·s

-3

S speed miles per hour or meters per 

second mph or m/s m·s

-1

T Celsius temperature degree Celsius °C K-273.15 

T torque (moment of force) newton meter N·m m2·kg·s

-2

t time second s s 

∆t time interval, period, 1/frequency second s s 

y generic variable 

(b) Symbols for chemical species. This part uses the following symbols for chemical 

species and exhaust constituents: 

Symbol Species

CH4 methane 

CO carbon monoxide 

CO2 carbon dioxide 

NMHC nonmethane hydrocarbon 

NMHCE nonmethane hydrocarbon equivalent 

NO nitric oxide 

NO2 nitrogen dioxide 

NOx oxides of nitrogen 

N2O nitrous oxide 

O2 molecular oxygen 

PM particulate mass 

THC total hydrocarbon 

THCE total hydrocarbon equivalent 

(c) Superscripts. This part uses the following superscripts to define a quantity: 

Superscript Quantity 

overbar (such as y ) arithmetic mean

(d) Subscripts. This part uses the following subscripts to define a quantity: 

Subscript Quantity 

int speed interval 

abs absolute quantity 

act actual or measured condition 

actint actual or measured condition over the speed interval 

atmos atmospheric 

b base 

c coastdown 

e effective 

error error

exp expected quantity 

i an individual of a series 

final final 

init initial quantity, typically before an emission test

max 

the maximum (i.e., peak) value expected at the standard over a 

test interval; not the maximum of an instrument range

meas measured quantity 

ref reference quantity 

rev revolution 

roll dynamometer roll 

s settling

sat saturated condition 

si speed interval 

Formatted Table
span span quantity 

test test quantity 

uncor uncorrected quantity 

zero zero quantity 

 (e) Other acronyms and abbreviations. This part uses the following additional 

abbreviations and acronyms: 

CFR Code of Federal Regulations 

EPA Environmental Protection Agency 

FID flame-ionization detector 

GVWR gross vehicle weight rating

NIST National Institute for Standards and Technology 

RESS rechargeable energy storage system

SAE Society of Automotive Engineers 

U.S.C. United States Code 

§1066.710 Reference materials. 

Documents listed in this section have been(a) Certain material is incorporated by 

reference into this part. with the approval of the Director of the Federal Register 

approved the incorporation by reference as prescribed in under 5 U.S.C. 552(a) and 1 

CFR part 51. Anyone may inspect copies at the To enforce any edition other than that 

specified in this section, the Environmental Protection Agency must publish a notice of 

the change in the Federal Register and the material must be available to the public. All 

approved material is available for inspection at U.S. EPA, Air and Radiation Docket and 

Information Center, 1301 Constitution Ave., NW., Room B102, EPA West Building, 

Washington, DC 20460 or, (202) 202-1744, and is available from the sources listed 

below. It is also available for inspection at the National Archives and Records 

Administration (NARA). For information on the availability of this material at NARA, 

call 202-–741-–6030, or go to:

http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

(a) NIST material. Table 1 of this section lists material from the National Institute of 

Standards and Technology that we have incorporated by reference. The first column lists 

the number and name of the material. The second column lists the section of this part 

where we reference it. Anyone may purchase copies of these materials from the 

Government Printing Office, Washington, DC 20402 or download them free from the 

Internet at www.nist.gov. Table 1 follows:

Table 1 of §1066.710–NIST materials

Document number and name Part 1066 reference

NIST Special Publication 811, 1995 Edition, Guide for the Use of the International System of 

Units (SI), Barry N. Taylor, Physics Laboratory 1066.20, 1066.705

(b) SAE material. Table 2 of this section lists material from the Society of Automotive 

Engineering that we have incorporated by reference. The first column lists the number 

and name of the material. The second column lists the sections of this part where we 

reference it. Anyone may purchase copies of these materials from the(b) Society of 

Automotive Engineers, 400 Commonwealth Drive., Warrendale, PA 15096 or www.–

0001, (877) 606–7323 (U.S. and Canada) or (724) 776–4970 (outside the U.S. and 

Canada), http://www.sae.org. Table 2 follows:
(1) SAE J1263, Road Load Measurement and Dynamometer Simulation Using 

Coastdown Techniques, Revised March 2010, IBR approved for §§ 1066.301(b) and 

1066.310(b). 

(2) SAE J2263, Road Load Measurement Using On-Board Anemometry and 

Coastdown Techniques, Revised December 2008, IBR approved for §§ 1066.301(b), 

and 1066.310(b).

(3) SAE J2711, Recommended Practice for Measuring Fuel Economy and Emissions 

of Hybrid-Electric and Conventional Heavy-Duty Vehicles, Issued September 2002, 

IBR approved for § 1066.501.

(c) National Institute of Standards and Technology, 100 Bureau Drive, Stop 1070, 

Gaithersburg, MD 20899-1070, (301) 975-6478, www.nist.gov, or inquiries@nist.gov.

(1) NIST Special Publication 811, 2008 Edition, Guide for the Use of the 

International System of Units (SI), Barry N. Taylor, Physics Laboratory, and Ambler 

Thompson, Technology Services, March 2008, IBR approved for §§ 1066.20(a) and 

1066.705.

(2) [Reserved] 

PART 1068—GENERAL COMPLIANCE PROVISIONS FOR HIGHWAY, 

STATIONARY, AND NONROAD PROGRAMS

92. The authority citation for part 1068 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

93. The heading of part 1068 is revised to read as set forth above.

Subpart A – [Amended]

94. Section 1068.1 is revised to read as follows:

§ 1068.1 Does this part apply to me?

(a) The provisions of this part apply to everyone with respect to the following engines 

and to equipment using the following engines (including owners, operators, parts 

manufacturers, and persons performing maintenance):

(1) Locomotives we regulate under 40 CFR part 1033.

(2) Heavy-duty motor vehicles and motor vehicle engines to the extent and in the 

manner specified in 40 CFR parts 85, 86, 1036 and 1037.

(3) Land-based nonroad compression-ignition engines we regulate under 40 CFR part 

1039.

(4) Stationary compression-ignition engines certified using the provisions of 40 CFR 

part 1039, as indicated in 40 CFR part 60, subpart IIII.

(5) Marine compression-ignition engines we regulate under 40 CFR part 1042.

(6) Marine spark-ignition engines we regulate under 40 CFR part 1045.

(7) Large nonroad spark-ignition engines we regulate under 40 CFR part 1048.

(8) Stationary spark-ignition engines certified using the provisions of 40 CFR parts 

1048 or 1054, as indicated in 40 CFR part 60, subpart JJJJ.

(9) Recreational engines and vehicles we regulate under 40 CFR part 1051 (such as 

snowmobiles and off-highway motorcycles).
(10) Small nonroad spark-ignition engines we regulate under 40 CFR part 1054.

(b) This part does not apply to any of the following engine or vehicle categories, except 

as specified in paragraph (d) of this section or as specified in other parts:

(1) Light-duty motor vehicles (see 40 CFR part 86).

(2) Highway motorcycles (see 40 CFR part 86).

(3) Aircraft engines (see 40 CFR part 87).

(4) Land-based nonroad compression-ignition engines we regulate under 40 CFR part 

89.

(5) Small nonroad spark-ignition engines we regulate under 40 CFR part 90.

(c) Paragraph (a) of this section identifies the parts of the CFR that define emission 

standards and other requirements for particular types of engines and equipment. This part 

1068 refers to each of these other parts generically as the “standard-setting part.” For 

example, 40 CFR part 1051 is always the standard-setting part for snowmobiles. Follow 

the provisions of the standard-setting part if they are different than any of the provisions 

in this part.

(d) Specific provisions in this part 1068 start to apply separate from the schedule for 

certifying engines to new emission standards, as follows:

(1) The provisions of §§ 1068.30 and 1068.310 apply for stationary spark-ignition 

engines built on or after January 1, 2004, and for stationary compression-ignition 

engines built on or after January 1, 2006.

(2) The provisions of §§ 1068.30 and 1068.235 apply for the types of 

engines/equipment listed in paragraph (a) of this section beginning January 1, 2004, if 

they are used solely for competition.

Subpart C – [Amended]

28.95. Section 1068.210 is revised to read as follows:

§1068.210 What are the provisions for exempting test engines/equipment?

(a) We may exempt engines/equipment that you will use for research, investigations, 

studies, demonstrations, or training. Note that you are not required to get an exemption 

under this section for engines that are exempted under other provisions of this part, such 

as the manufacturer-owned exemption in §1068.215.

(b) Anyone may ask for a testing exemption. 

(c) If you are a certificate holder, you may request an exemption for engines/equipment 

you intend to include in test programs over a two-year period. 

(1) In your request, tell us the maximum number of engines/equipment involved and 

describe how you will make sure exempted engines/equipment are used only for this 

testing. For example, if the exemption will involve other companies using your 

engines/equipment, describe your plans to track individual units so you can properly 

report on their final disposition. 

(2) Give us the information described in paragraph (d) of this section if we ask for it.

 (d) If you are not a certificate holder, do all the following things: 

(1) Show that the proposed test program has a valid purpose under paragraph (a) of 

this section.
(2) Show you need an exemption to achieve the purpose of the test program (time 

constraints may be a basis for needing an exemption, but the cost of certification 

alone is not).

(3) Estimate the duration of the proposed test program and the number of 

engines/equipment involved.

(4) Allow us to monitor the testing.

(5) Describe how you will ensure that you stay within this exemption’s purposes. 

Address at least the following things:

(i) The technical nature of the test.

(ii) The test site.

(iii) The duration and accumulated engine/equipment operation associated with 

the test.

(iv) Ownership and control of the engines/equipment involved in the test.

(v) The intended final disposition of the engines/equipment.

(vi) How you will identify, record, and make available the engine/equipment 

identification numbers.

(vii) The means or procedure for recording test results.

(e) If we approve your request for a testing exemption, we will send you a letter or a 

memorandum describing the basis and scope of the exemption. It will also include any 

necessary terms and conditions, which normally require you to do the following:

(1) Stay within the scope of the exemption.

(2) Create and maintain adequate records that we may inspect.

(3) Add a permanent label to all engines/equipment exempted under this section, 

consistent with §1068.45, with at least the following items: 

(i) The label heading "EMISSION CONTROL INFORMATION".

(ii) Your corporate name and trademark.

(iii) Engine displacement, family identification, and model year of the 

engine/equipment (as applicable), or whom to contact for further information.

(iv) One of these statements (as applicable):

(A) “THIS ENGINE IS EXEMPT UNDER 40 CFR 1068.210 OR 1068.215 

FROM EMISSION STANDARDS AND RELATED REQUIREMENTS.” 

(B) “THIS EQUIPMENT IS EXEMPT UNDER 40 CFR 1068.210 OR 

1068.215 FROM EMISSION STANDARDS AND RELATED 

REQUIREMENTS.”

(4) Tell us when the test program is finished.

(5) Tell us the final disposition of the engines/equipment.

(6) Send us a written confirmation that you meet the terms and conditions of this 

exemption.

96. Section 1068.235 is revised to read as follows:

§ 1068.235 What are the provisions for exempting engines/equipment used solely 

for competition?

(a) New engines/equipment you produce that are used solely for competition are 

generally excluded from emission standards. See the standard-setting parts for specific 

provisions where applicable.
(b) If you modify any nonroad engines/equipment after they have been placed into 

service in the United States so they will be used solely for competition, they are exempt 

without request. This exemption applies only to the prohibition in §1068.101(b)(1) and is 

valid only as long as the engine/equipment is used solely for competition. You may not 

use the provisions of this paragraph (b) to circumvent the requirements that apply to the 

sale of new competition engines under the standard-setting part.

(c) If you modify any nonroad engines/equipment under paragraph (b) of this section, you 

must destroy the original emission labels. If you loan, lease, sell, or give any of these 

engines/equipment to someone else, you must tell the new owner (or operator, if 

applicable) in writing that they may be used only for competition.

Subpart D – [Amended]

29.97. Section 1068.325 is revised to read as follows:

§1068.325 What are the temporary exemptions for imported engines/equipment?

You may import engines/equipment under certain temporary exemptions, subject to the 

conditions in this section. We may ask U.S. Customs and Border Protection to require a 

specific bond amount to make sure you comply with the requirements of this subpart. 

You may not sell or lease one of these engines/equipment while it is in the United States 

except as specified in this section or §1068.201(i). You must eventually export the 

engine/equipment as we describe in this section unless it conforms to a certificate of 

conformity or it qualifies for one of the permanent exemptions in §1068.315. 

(a) Exemption for repairs or alterations. You may temporarily import nonconforming 

engines/equipment under bond solely for repair or alteration, subject to our advance 

approval as described in paragraph (j) of this section. You may operate the 

engine/equipment in the United States only as necessary to repair it, alter it, or ship it to 

or from the service location. Export the engine/equipment directly after servicing is

complete.

(b) Testing exemption. You may temporarily import nonconforming engines/equipment 

under bond for testing if you follow the requirements of §1068.210, subject to our 

advance approval as described in paragraph (j) of this section. You may operate the 

engines/equipment in the United States only as needed to perform tests. This exemption 

expires one year after you import the engine/equipment unless we approve an extension. 

The engine/equipment must be exported before the exemption expires. You may sell or 

lease the engines/equipment consistent with the provisions of §1068.210.

(c) Display exemption. You may temporarily import nonconforming engines/equipment 

under bond for display if you follow the requirements of§1068.220, subject to our 

advance approval as described in paragraph (j) of this section. This exemption expires 

one year after you import the engine/equipment, unless we approve your request for an 

extension. We may approve an extension of up to one more year for each request, but no 

more than three years total. The engine/equipment must be exported by the time the 

exemption expires or directly after the display concludes, whichever comes first. 

(d) Export exemption. You may temporarily import nonconforming engines/equipment 

to export them, as described in §1068.230. You may operate the engine/equipment in the 

United States only as needed to prepare it for export. Label the engine/equipment as 
described in §1068.230. You may sell or lease the engines/equipment for operation 

outside the United States consistent with the provisions of §1068.230.

(e) Diplomatic or military exemption. You may temporarily import nonconforming 

engines/equipment without bond if you represent a foreign government in a diplomatic or 

military capacity. In your request to the Designated Compliance Officer (see §1068.305), 

include either written confirmation from the U.S. State Department that you qualify for 

this exemption or a copy of your orders for military duty in the United States. We will 

rely on the State Department or your military orders to determine when your diplomatic 

or military status expires, at which time you must export your exempt engines/equipment.

(f) Delegated-assembly exemption. You may import a nonconforming engine for final 

assembly under the provisions of §1068.261. You may sell or lease the 

engines/equipment consistent with the provisions of §1068.261.

(g) Exemption for partially complete engines. You may import an engine if another 

company already has a certificate of conformity and will be modifying the engine to be in 

its final certified configuration or a final exempt configuration under the provisions of 

§1068.262. You may also import a partially complete engine by shipping it from one of 

your facilities to another under the provisions of §1068.260(c). If you are importing a 

used engine that becomes new as a result of importation, you must meet all the 

requirements that apply to original engine manufacturers under §1068.262. You may sell 

or lease the engines consistent with the provisions of §1068.262.

(h) [Reserved]

(i) [Reserved]

(j) Approvals. For the exemptions in this section requiring our approval, you must send a 

request to the Designated Compliance Officer before importing the engines/equipment. 

We will approve your request if you meet all the applicable requirements and conditions. 

If another section separately requires that you request approval for the exemption, you 

may combine the information requirements in a single request. Include the following 

information in your request:

(1) Identify the importer of the engine/equipment and the applicable postal address, email address, and telephone number.

(2) Identify the engine/equipment owner and the applicable postal address, e-mail 

address, and telephone number.

(3) Identify the engine/equipment by model number (or name), serial number, and 

original production year.

(4) Identify the specific regulatory provision under which you are seeking an 

exemption.

(5) Authorize EPA enforcement officers to conduct inspections or testing as allowed 

under the Clean Air Act.

(6) Include any additional information we specify for demonstrating that you qualify 

for the exemption. 
Table 2 of §1066.710–SAE materials

Document number and name Part 1066 reference

SAE J1711:2010, Recommended Practice for Measuring the Exhaust Emissions and Fuel Economy 

of Hybrid-Electric Vehicles 1066.41066.501

SAE J2263:2008, Road Load Measurement Using On-Board Anemometry And Coastdown 

Techniques

1066.21066.301, 

1066.21066.310, 

1066.31066.404

SAE J2264:1995, Chassis Dynamometer Simulation Of Road Load Using Coastdown Techniques 1066.31066.404

SAE J2711: 2002, Recommended Practice for Measuring Fuel Economy and Emissions of HybridElectric and Conventional Heavy-Duty Vehicles 1066.41066.501

________________________________________________________________________

Department of Transportation 

National Highway Traffic Safety Administration 

49 CFR Chapter V 

In consideration of the foregoing, under the authority of 49 U.S.C. 32901 and 32902 and 

delegation of authority at 49 CFR 1.50, NHTSA proposes to amend 49 CFR chapter V as 

follows: 

PART 523 — VEHICLE CLASSIFICATION 

■1898. The authority for part 523 continues to read as follows: 

Authority: 49 U.S.C. 32901; delegation of authority at 49 CFR 1.50. 

■1999. Revise § 523.2 to read as follows: 

§ 523.2 Definitions. 

Approach angle means the smallest angle, in a plane side view of an automobile, 

formed by the level surface on which the automobile is standing and a line tangent to the 

front tire static loaded radius arc and touching the underside of the automobile forward of 

the front tire. 

Axle clearance means the vertical distance from the level surface on which an 

automobile is standing to the lowest point on the axle differential of the automobile. 

Base tire means the tire specified as standard equipment by a manufacturer on each 

vehicle configurationsubconfiguration of a model type. 

Basic vehicle frontal area is used as defined in 40 CFR 86.1803-01. 

Breakover angle means the supplement of the largest angle, in the plan side view of 

an automobile that can be formed by two lines tangent to the front and rear static loaded 

radii arcs and intersecting at a point on the underside of the automobile. 

Cab-complete vehicle means a vehicle that is first sold as an incomplete vehicle that 

substantially includes the vehicle cab section as defined in 40 CFR 1037.801. For 

example, vehicles known commercially as chassis-cabs, cab-chassis, box-deletes, beddeletes, cut-away vans are considered cab-complete vehicles. A cab includes a steering 
column and passenger compartment. Note a vehicle lacking some components of the cab 

is a cab-complete vehicle if it substantially includes the cab. 

Cargo-carrying volume means the luggage capacity or cargo volume index, as 

appropriate, and as those terms are defined in 40 CFR 600.315, in the case of automobiles 

to which either of those terms apply. With respect to automobiles to which neither of 

those terms apply “cargo-carrying volume” means the total volume in cubic feet rounded 

to the nearest 0.1 cubic feet of either an automobile's enclosed nonseating space that is 

intended primarily for carrying cargo and is not accessible from the passenger 

compartment, or the space intended primarily for carrying cargo bounded in the front by 

a vertical plane that is perpendicular to the longitudinal centerline of the automobile and 

passes through the rearmost point on the rearmost seat and elsewhere by the automobile's 

interior surfaces. 

Class 2b vehicles are vehicles with a gross vehicle weight rating (GVWR) ranging 

from 8,501 to 10,000 pounds. 

Class 3 through Class 8 vehicles are vehicles with a gross vehicle weight rating 

(GVWR) of 10,001 pounds or more as defined in 49 CFR 565.15. 

Commercial medium- and heavy-duty on-highway vehicle means an on-highway 

vehicle with a gross vehicle weight rating of 10,000 pounds or more as defined in 49 

U.S.C. 32901(a)(7). 

Completed vehicle means a vehicle that requires no further manufacturing operations 

to perform its intended function and is a functioning vehicle that has the primary load 

carrying device or container (or equivalent equipment) attached or that is designed to pull 

a trailer. Examples of equivalent equipment would include fifth wheel trailer hitches, 

firefighting equipment, and utility booms.

Curb weight is defined the same as vehicle curb weight in 40 CFR 86.1803-01. 

Departure angle means the smallest angle, in a plane side view of an automobile, 

formed by the level surface on which the automobile is standing and a line tangent to the 

rear tire static loaded radius arc and touching the underside of the automobile rearward of 

the rear tire. 

Final stage manufacturer has the meaning given in 49 CFR 567.3.

Footprint is defined as the product of track width (measured in inches, calculated as 

the average of front and rear track widths, and rounded to the nearest tenth of an inch) 

times wheelbase (measured in inches and rounded to the nearest tenth of an inch), divided 

by 144 and then rounded to the nearest tenth of a square foot. For purposes of this 

definition, track width is the lateral distance between the centerlines of the base tires at 

ground, including the camber angle. For purposes of this definition, wheelbase is the 

longitudinal distance between front and rear wheel centerlines. 

Gross combination weight rating or GCWR means the value specified by the 

manufacturer as the maximum allowable loaded weight of a combination vehicle (e.g. 

tractor plus trailer). 

Gross vehicle weight rating or GVWR means the value specified by the vehicle 

manufacturer as the maximum design loaded weight of a single vehicle (e.g. vocational 

truck). vehicle). 

Heavy-duty engine means any engine used for (or for which the engine manufacturer 

could reasonably expect to be used for) motive power in a heavy-duty vehicle. For 

purposes of this definition in this part, the term “engine” includes internal combustion 
engines and other devices that convert chemical fuel into motive power. For example, a 

fuel cell and motor used in a heavy-duty vehicle is a heavy-duty engine.

Heavy-duty truckvehicle means a non-passenger automobile meeting the 

criteriavehicle that as defined in § 523.6. 

Heavy-duty off-road truckvehicle means a heavy-duty vocational truck or tractor that 

vehicle or vocational tractor that is intended for off-road use meeting either the criteria of 

paragraph (1) or (2). 

(1) Vehicles with tires installed having a maximum speed rating at or below 55 mph. 

(2) Vehicles primarily or partially performsdesigned to perform work off-road or to 

performs off-road (such as in oil fields, forests, or construction sites and having 

permanently or temporarily), and meeting at least one of the criteria of paragraph (2)(i) of 

this section and at least one of the criteria of paragraph (2)(ii) of this section. 

(i) Vehicle must have affixed components designed to work in an off-road 

environment (i.e.,for example, hazardous material equipment or off-road drilldrilling

equipment) or characteristicswas designed to operate at low speeds making them 

unsuitable for normal highway operation on roads; and meeting one or more of the 

following criteria:.

Any vehicle performing primarily off-road and equipped with(ii) Vehicles must:

(A) Have an axle that has a gross axle weight rating (GAWR) of 29,000 pounds; or

more;

Any vehicle performing primarily off-road and that has(B) Have a speed attainable in 

2 miles of not more than 33 mph; or 

Any vehicle performing primarily off-road and that has(C) Have a speed attainable in 

2 miles of not more than 45 mph, an unloaded vehicle weight that is not less than 95 

percent of its gross vehicle weight rating (GVWR), and no capacity to carry occupants 

other than the driver and operating crew, or.

Any vehicle that can operate in both on and off-road environments and having speed 

restricted tires rated at 55 mph or below.

Incomplete vehicle means an assemblage consisting, at a minimum, of chassis (including 

the frame) structure, power train, steering system, suspension system, and braking 

system, in the state that those systems are to be part of the completed vehicle, but requires 

further manufacturing operations to become a completed vehicle.

Incomplete vehicle means a vehicle which does not have the primary load carrying 

device or container attached when it is first sold as a vehicle or any vehicle that does not 

meet the definition of a complete vehicle. This may include vehicles sold to secondary 

vehicle manufacturers. Incomplete vehicles include cab-complete vehicles. 

Innovative technology means technology certified under 40 CFR part 1037.610.

Light truck means a non-passenger automobile meeting the criteria in § 523.5.

Medium duty passenger vehicle means a vehicle which would satisfy the criteria in 

§ 523.5 (relating to light trucks) but for its gross vehicle weight rating or its curb weight, 

which is rated at more than 8,500 lbs GVWR or has a vehicle curb weight of more than 

6,000 pounds or has a basic vehicle frontal area in excess of 45 square feet, and which is 

designed primarily to transport passengers, but does not include a vehicle that: 

(1) Is an “incomplete truckvehicle”' as defined in this subpart; or 

(2) Has a seating capacity of more than 12 persons; or 

(3) Is designed for more than 9 persons in seating rearward of the driver's seat; or 
(4) Is equipped with an open cargo area (for example, a pick-up truck box or bed) of 

72.0 inches in interior length or more. A covered box not readily accessible from the 

passenger compartment will be considered an open cargo area for purposes of this 

definition. 

Motor home has the meaning given in 49 CFR 571.3. 

Motor vehicle has the meaning given in 40 CFR 85.1703.

Passenger-carrying volume means the sum of the front seat volume and, if any, rear 

seat volume, as defined in 40 CFR 600.315, in the case of automobiles to which that term 

applies. With respect to automobiles to which that term does not apply, ``passengercarrying volume'' means the sum in cubic feet, rounded to the nearest 0.1 cubic feet, of 

the volume of a vehicle's front seat and seats to the rear of the front seat, as applicable, 

calculated as follows with the head room, shoulder room, and leg room dimensions 

determined in accordance with the procedures outlined in Society of Automotive 

Engineers Recommended Practice J1100a, Motor Vehicle Dimensions (Report of Human 

Factors Engineering Committee, Society of Automotive Engineers, approved September 

1973 and last revised September 1975). 

(1) For front seat volume, divide 1,728 into the product of the following SAE 

dimensions, measured in inches to the nearest 0.1 inches, and round the quotient to the 

nearest 0.001 cubic feet. 

(i) H61-Effective head room--front. 

(ii) W3-Shoulder room--front. 

(iii) L34-Maximum effective leg room-accelerator. 

(2) For the volume of seats to the rear of the front seat, divide 1,728 into the product 

of the following SAE dimensions, measured in inches to the nearest 0.1 inches, and 

rounded the quotient to the nearest 0.001 cubic feet. 

(i) H63-Effective head room--second. 

(ii) W4-Shoulder room--second. 

(iii) L51-Minimum effective leg room--second. 

Pickup truck means a non-passenger automobile which has a passenger compartment 

and an open cargo area (bed). 

Recreational vehicle or RV means a motor vehicle equipped with living space and 

amenities found in a motor home. 

Running clearance means the distance from the surface on which an automobile is 

standing to the lowest point on the automobile, excluding unsprung weight. 

Static loaded radius arc means a portion of a circle whose center is the center of a 

standard tire-rim combination of an automobile and whose radius is the distance from 

that center to the level surface on which the automobile is standing, measured with the 

automobile at curb weight, the wheel parallel to the vehicle's longitudinal centerline, and 

the tire inflated to the manufacturer's recommended pressure. 

Temporary living quarters means a space in the interior of an automobile in which 

people may temporarily live and which includes sleeping surfaces, such as beds, and 

household conveniences, such as a sink, stove, refrigerator, or toilet. 

Van means a vehicle with a body that has an integral enclosure fully enclosinges the 

driver compartment and loada cargo carrying or work performing compartment. The 

distance from the leading edge of the windshield to the foremost body section of vans is 

typically shorter than that of pickup trucks and sport utility vehicles. 
Vocational vehicle means a vehicle that is constructedequipped for a particular 

industry, trade or occupation such as construction, heavy hauling, mining, logging, oil 

fields and refuse, refuse and includes vehicles such as school buses, motorcoaches and 

RVs. 

Vocational tractor means a tractor that is classified as a vocational vehicle because it 

meets one of the following design characteristics. 

(i) Low-roof tractors intended for intra-city pickup and delivery, such as those that 

deliver bottled beveragesaccording to retail stores.40 CFR part 1037.630

(ii) Tractors intended for off-road operation (including mixed service operation), such as 

those with reinforced frames and increased ground clearance. 

(iii) Tractors with a GCWR over 120,000 pounds.

Work truck means a vehicle that is rated at more than 8,500 pounds and less than or 

equal to 10,000 pounds gross vehicle weight, and is not a medium-duty passenger vehicle

as defined in 40 CFR 86.1803-01 effective as of December 20, 2007. 

■ 20100. Add a new § 523.6 to read as follows: 

§ 523.6 Heavy-duty truckvehicle. 

(a) A heavy-duty truckvehicle is any Class 2b through 8 non-passenger vehicle that is 

a commercial medium- and heavy-duty on highway vehicle or a work truck, as defined in 

49 U.S.C. 32901(a)(7) and (19). For the purpose of this regulation heavy-duty 

trucksvehicles are divided into three regulatory categories as follows: 

(1) Heavy-duty pickup trucks and vans; 

(2) Heavy-duty vocational trucksvehicles; and 

(3) Truck tractors with a GVWR above 26,000 pounds. 

(b) The heavy-duty truckvehicle classification does not include: 

(1) Vehicles defined as medium duty passenger vehicles in 40 CFR 86.1803-01 on 

December 20, 2007. 

(2) Recreational vehicles including motor homes.

(3) Vehicles excluded from the definition of “heavy-duty truckvehicle” because of 

vehicle weight or weight rating (such as light duty vehicles and light duty trucks as 

defined in § 523.5). 

(4) Heavy-duty off-road vehicles3) Vehicles excluded from the definition of motor 

vehicle in 40 CFR part 85.1703. 

■ 21101. Add a new § 523.7 to read as follows: 

§ 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 and include 

cab-complete vehicles that are first sold as incomplete vehicles that substantially include 

the vehicle cab section. or manufactured as incomplete vehicles as designated by a 

manufacturer. A manufacturer may also optionally designate incomplete or complete 
Class 4 or 5 vehicles as heavy-duty pickup trucks or vans or spark ignition (or gasoline) 

engines certified and sold as loose engines manufactured for use in heavy-duty pickup 

trucks or vans. See references in 40 CFR part 1037.104 and 40 CFR part 1037.150. 

■ 22102. Add a new § 523.8 to read as follows: 

§ 523.8 Heavy-duty vocational trucksvehicle. 

Heavy-duty vocational trucksvehicles are vocational vehicles with a gross vehicle 

weight rating (GVWR) above 8,500 pounds excluding: 

(a) Heavy-duty pickup trucks and vans defined in § 523.7; 

(b) Medium duty passenger vehicles; and 

(c) Truck tractors, except vocational tractors, with a GVWR above 26,000 pounds; 

■ 23103. Add a new § 523.9 to read as follows: 

§ 523.9 Truck tractors. 

Truck tractors for the purpose of this part are considered as any truck tractor as 

defined in 49 CFR part 571 having a GVWR above 26,000 pounds and include any 

heavy-duty vocational truck with a sleeper cab. 

PART 534—RIGHTS AND RESPONSIBILITIES OF MANUFACTURERS IN 

THE CONTEXT OF CHANGES IN CORPORATE RELATIONSHIPS 

■ 24104. The authority for part 534 continues to read as follows: 

Authority: 49 U.S.C. 32901; delegation of authority at 49 CFR 1.50. 

■ 25105. Revise § 534.1 to read as follows: 

§ 534.1 Scope. 

This part defines the rights and responsibilities of manufacturers in the context of 

changes in corporate relationships for purposes of the fuel economy and fuel 

consumption programs established by 49 U.S.C. chapter 329. 

■ 26106. Revise § 534.2 to read as follows: 

§ 534.2 Applicability. 

This part applies to manufacturers of passenger automobiles, light trucks, heavy-duty 

trucksvehicles and the engines manufactured for use in heavy-duty trucksvehicles as 

defined in 49 CFR part 523. 

■ 27107. Revise § 534.4 to read as follows. 
§ 534.4 Successors and predecessors. 

For purposes of the fuel economy and fuel consumption programs, ‘‘manufacturer’’ 

includes ‘‘predecessors’’ and ‘‘successors’’ to the extent specified in paragraphs (a) 

through (d) of this section. 

(a) Successors are responsible for any civil penalties that arise out of fuel economy 

and fuel consumption shortfalls incurred and not satisfied by predecessors. 

(b) If one manufacturer has become the successor of another manufacturer during a 

model year, all of the vehicles or engines produced by those manufacturers during the 

model year are treated as though they were manufactured by the same manufacturer. A 

manufacturer is considered to have become the successor of another manufacturer during 

a model year if it is the successor on September 30 of the corresponding calendar year 

and was not the successor for the preceding model year. 

(c)(1) For passenger automobiles and light trucks, fuel economy credits earned by a 

predecessor before or during model year 2007 may be used by a successor, subject to the

availability of credits and the general three-year restriction on carrying credits forward 

and the general three-year restriction on carrying credits backward. Fuel economy credits 

earned by a predecessor after model year 2007 may be used by a successor, subject to the 

availability of credits and the general five-year restriction on carrying credits forward and 

the general three-year restriction on carrying credits backward. 

(2) For heavy-duty trucksvehicles and heavy-duty truckvehicle engines, available fuel 

consumption credits earned by a predecessor after model year 2015, and in model years 

2013, 2014 and 2015 if a manufacturer voluntarily complies in those model years, may be 

used by a successor, subject to the availability of credits and the general five-year 

restriction on carrying credits forward and the general three year restriction on carrying 

credits backward.

(d)(1) For passenger automobiles and light trucks, fuel economy credits earned by a 

successor before or during model year 2007 may be used to offset a predecessor’s 

shortfall, subject to the availability of credits and the general three-year restriction on 

carrying credits forward and the general three-year restriction on carrying credits 

backward. Credits earned by a successor after model year 2007 may be used to offset a 

predecessor’s shortfall, subject to the availability of credits and the general five-year 

restriction on carrying credits forward and the general three-year restriction on carrying 

credits backward. 

(2) For heavy-duty trucksvehicles and heavy-duty truckvehicle engines, available 

credits earned by a successor after model year 2015, and in model years 2013, 2014 and 

2015, if a manufacturer voluntarily complies in those model years, may be used by a 

predecessor subject to the availability of credits and the general five-year restriction on 

carrying credits forward and the general three year restriction on carrying credits 

backward. 

■ 28108. Amend § 534.5 by revising paragraphs (a), (c), and (d) to read as follows: 

§ 534.5 Manufacturers within control relationships. 
(a) If a civil penalty arises out of a fuel economy or fuel consumption shortfall 

incurred by a group of manufacturers within a control relationship, each manufacturer 

within that group is jointly and severally liable for the civil penalty.

* * * * * 

(c)(1) For passenger automobiles and light trucks, fuel economy credits of a 

manufacturer within a control relationship may be used by the group of manufacturers 

within the control relationship to offset shortfalls, subject to the agreement of the other 

manufacturers, the availability of the credits, and the general three year restriction on 

carrying credits forward or backward prior to or during model year 2007, or the general 

five year restriction on carrying credits forward and the general three-year restriction on 

carrying credits backward after model year 2007. 

(2) For heavy-duty trucksvehicles and heavy-duty engines, credits of a manufacturer 

within a control relationship may be used by the group of manufacturers within the 

control relationship to offset shortfalls, subject to the agreement of the other 

manufacturers, the availability of the credits to carry forward without restriction, except 

for the heavy-duty pickup truck and van category that have a 5-year carry forward expiry 

date, the general 5-year restriction on carrying credits forward, and the general three year 

restriction on offsetting past credit shortfalls as specified in the requirements of 49 CFR 

535.7. 

(d)(1) For passenger automobiles and light trucks, if a manufacturer within a group of 

manufacturers is sold or otherwise spun off so that it is no longer within that control 

relationship, the manufacturer may use credits that were earned by the group of 

manufacturers within the control relationship while the manufacturer was within that 

relationship, subject to the agreement of the other manufacturers, the availability of the 

credits, and the general three-year restriction on carrying credits forward or backward 

prior to or during model year 2007, or the general five-year restriction on carrying credits 

forward and the general three-year restriction on carrying credits backward after model 

year 2007. 

(2) For heavy-duty trucksvehicles and heavy-duty truckvehicle engines, if a 

manufacturer within a group of manufacturers is sold or otherwise spun off so that it is no 

longer within that control relationship, the manufacturer may use credits that were earned 

by the group of manufacturers within the control relationship while the manufacturer was 

within that relationship, subject to the agreement of the other manufacturers, the 

availability of the credits, the general 5-year restriction on carrying credits forward, and 

the general three year restriction on offsetting past credit shortfalls as specified in the 

requirements of 49 CFR 535.7.

* * * * * 

■ 2109. Revise § 534.6 to read as follows. 

§ 534.6 Reporting corporate transactions. 

Manufacturers who have entered into written contracts transferring rights and 

responsibilities such that a different manufacturer owns the controlling stock or exerts 

control over the design, production or sale of automobiles or heavy-duty trucksvehicles to 

which Corporate Average Fuel Economy or Fuel Consumption standards apply shall 

report the contract to the agency as follows: 
(a) The manufacturers must file a certified report with the agency affirmatively 

stating that the contract transfers rights and responsibilities between them such that one 

manufacturer has assumed a controlling stock ownership or control over the design, 

production or sale of vehicles. The report must also specify the first full model year to 

which the transaction will apply. 

(b) Each report shall— 

(1) Identify each manufacturer; 

(2) State the full name, title, and address of the official responsible for preparing the 

report; 

(3) Identify the production year being reported on; 

(4) Be written in the English language; and 

(5) Be submitted to: Administrator, National Highway Traffic Safety Administration, 

1200 New Jersey Avenue, SE, Washington, DC 20590. 

(c) The manufacturers may seek confidential treatment for information provided in 

the certified report in accordance with 49 CFR part 512. 

30 ■ 110. A new part 535 is added to chapter V to read as follows: 

PART 535 MEDIUM- AND HEAVY-DUTY VEHICLE FUEL EFFICIENCY 

PROGRAM 

Sec. 

535.1 Scope. 

535.2 Purpose. 

535.3 Applicability. 

535.4 Definitions. 

535.5 Standards. 

535.6 Measurement and calculation procedures. 

535.7 Averaging, banking, and trading (ABT) program. 

535.8 Reporting requirements. 

535.9 Enforcement approach. 

Authority: 49 U.S.C. 32902; delegation of authority at 49 CFR 1.50. 

§ 535.1 Scope. 

This part establishes fuel consumption standards pursuant to 49 U.S.C. 32902(k) for 

work trucks and commercial medium-duty and heavy-duty on-highway vehicles 

(hereafter referenced as heavy-duty trucksvehicles) and engines manufactured for sale in 

the United States and establishes a credit program manufacturers may use to comply with 

standards and requirements for manufacturers to provide reports to the National Highway 

Traffic Safety Administration regarding their efforts to reduce the fuel consumption of 

these vehicles. 

 
§ 535.2 Purpose. 

The purpose of this part is to reduce the fuel consumption of new heavy-duty 

trucksvehicles by establishing maximum levels for fuel consumption standards while 

providing a flexible credit program to assist manufacturers in complying with standards. 

§ 535.3 Applicability. 

(a) This part applies to complete vehicle and chassis manufacturers of all new heavyduty trucksvehicles, as defined in 49 CFR part 523, and to the manufacturers of all 

heavy-duty engines manufactured for use in the applicable vehicles (hereafter 

referenced as heavy-duty engines).for each given model year. 

(b) Vehicle manufacturerComplete vehicle manufacturers, for the purpose of this 

part, means a manufacturerinclude manufacturers that manufacturesproduce heavyduty pickup trucks and vans or truck tractors as complete vehicles. and that hold the EPA 

certificate of conformity. 

(c) Chassis manufacturers, for the purpose of this part, include manufacturers that 

produce incomplete vehicles constructed for use as heavy-duty pickup trucks or vans or 

heavy-duty vocational vehicles and that hold the EPA certificate of conformity. Some 

vocational vehicle manufacturers are both chassis and complete vehicle manufacturers. 

These manufacturers will be regulated as chassis manufacturers under this program. 

(d) Engine manufacturer, for the purpose of this part, means a manufacturer that 

manufactures the chassis of a vocational vehiclemanufacturers engines for 

heavy-duty vehicles and holds the EPA certificate of conformity. 

(de) The heavy-duty vehicles, chassis and engines excluded from the requirements of 

this part include: 

(1) Engines used in medium-duty passenger Recreational vehicles. , including 

motor homes.

(2) Engines fueled by other than petroleum fuels, natural gas, liquefied petroleum gas, 

and methanol.

(e)(2) Vehicles and engines exempted by EPA in accordance with 40 CFR part 1036 

and 40 CFR 1037. 

(f) Vehicles and engines produced by small business manufacturers as defined by the 

Small Business Administration at 13 CFR 121.201, and are exempted as reported to 

and approved byspecified in § 535.8(h). 

 (g) Heavy-duty off-road vehicles meeting the Administratorscriteria in 49 CFR part 

523 are exempt without request from vehicle standards of § 535.5(b). Manufacturers of 

vehicles not meeting the criteria for the heavy-duty off-road vehicle exclusion may 

submit a petition as specified in § 535.8(h) to EPA and NHTSA, are exempted for an 

exclusion from the requirementsvehicle standards of this regulation.§ 535.5(b).

(h) A vehicle manufacturer that completes assembly of a vehicle at two or more 

facilities may ask to use as the date of manufacture for that vehicle the date on which 

manufacturing is completed at the place of main assembly, consistent with provisions of 

49 CFR 567.4, as the model year. Note that such staged assembly is subject to the 

provisions of 40 CFR 1068.260(c). NHTSA’s allowance of this provision is effective 

when EPA approves the manufacturer’s certificates of conformity for these vehicles. 
§ 535.4 Definitions. 

The terms manufacture and manufacturer are used as defined in section 501 of the

Act and the terms commercial medium-duty and heavy-duty on -highway vehicle, fuel 

and work truck are used as defined in 49 U.S.C. 32901.

A to B testing means testing performed in pairs to allow comparison of vehicle A to 

vehicle B.

Act means the Motor Vehicle Information and Cost Savings Act, as amended by Pub. 

L. 94–163 and 96–425. 

Administrator means the Administrator of the National Highway Traffic Safety 

Administration (NHTSA) or the Administrator's delegate. 

Advanced technology means vehicle technology certified under 40 CFR part 

1036.615 and 40 CFR part 1037.615.

Averaging set means, a set of engines or vehicles in which fuel consumption credits

may be exchanged. Credits generated by one engine or vehicle family may only be used 

by other respective engine or vehicle families in the same averaging set. Note that an 

averaging set may comprise more than one regulatory subcategory. The averaging sets 

for this HD program are defined as follows: 

(1) Heavy-duty pickup trucks and vans.

(2) Vocational light-heavy vehicles at or below 19,500 pounds GVWR. 

(3) Vocational and tractor medium-heavy vehicles above 19,500 pounds GVWR but 

at or below 33,000 pounds GVWR. 

(4) Vocational and tractor heavy-heavy vehicles above 33,000 pounds GVWR. 

(5) Compression-ignition light heavy-duty diesel engines for Class 2b to 5 

trucksvehicles with a GVWR above 8,500 pounds but at or below 19,500 pounds. 

(6) Compression-ignition medium heavy-duty diesel engines for Class 6 and 7 

trucksvehicles with a GVWR above 19,500 but at or below 33,000 pounds. 

(7) Compression-ignition heavy heavy-duty diesel engines for Class 8 trucksvehicles

with a GVWR above 33,000 pounds. 

(8) Spark ignition engines in Class 2b to 8 trucksvehicles with a GVWR above 8,500 

pounds. 

Cab-complete vehicle has the meaning given in 49 CFR part 523. 

Carryover means relating to certification based on emission data generated from an 

earlier model year. 

Certification means process of obtaining a certificate of conformity for a vehicle 

family that complies with the emission standards and requirements in this part. 

Certificate of Conformity means an approval document granted by the EPA to a 

manufacturer that submits an application for a vehicle or engine emissions family in 40 

CFR part 1036.205 and 40 CFR part 1037.205. A certificate of conformity is valid from

the indicated effective date until December 31 of the model year for which it is issued. 

The certificate must be renewed annually for any vehicle a manufacturer continues to 

produce.

Certified emission level means the highest deteriorated emission level in an engine 

family for a given pollutant from the applicable transient and/or steady-state testing 

rounded to the same number of decimal places as the applicable standard. Note that you 
may have two certified emission levels for CO2 if you certify a family for both vocational 

and tractor use.

Certificate holder means the manufacturer who holds the certificate of conformity for 

the vehicle or engine and that assigns the model year based on the date when its 

manufacturing operations are completed relative to its annual model year period.

Chassis-cab means the incomplete part of a vehicle that includes a frame, a 

completed occupant compartment and that requires only the addition of cargo-carrying, 

work-performing, or load-bearing components to perform its intended functions. 

Chief Counsel means the NHTSA Chief Counsel, or his or her designee. 

Complete sister vehicle is a complete vehicle of the same configuration as a cabcomplete vehicle.

Complete vehicle has the meaning given in 49 CFR part 523. 

Compression-ignition means relating to a type of reciprocating, internal-combustion 

engine, such as a diesel engine, that is not a spark-ignition engine. 

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 the 

EPA designates. 

Credits (or fuel consumption credits) in this part means an earned allowance 

recognizing the fuel consumption of a particular manufacturer’s vehicles or engines 

within a particular averaging set exceeds (credit surplus or positive credits) or falls 

below (credit shortfall, deficit or negative credits) that manufacturer’s fuel consumption 

standard(s) for the regulatory subcategory(s) that make-up the averaging set for a given 

model year, or purchased allowance. The value of aan earned credit is calculated 

according to § 535.7. 

Curb weight has the meaning given in 40 CFR 86.1803-01. 

Date of manufacture means the date on which the certifying vehicle manufacturer 

completes its manufacturing operations, except as follows:

(1) Where the certificate holder is an engine manufacturer that does not manufacture 

the chassis, the date of manufacture of the vehicle is based on the date assembly of the 

vehicle is completed.

(2) EPA and NHTSA may approve an alternate date of manufacture based on the date 

on which the certifying (or primary) vehicle manufacturer completes assembly at the 

place of main assembly, consistent with the provisions of §1037.601 and 49 CFR 567.4.

Day cab means a type of truck tractor cab that is not a “sleeper cab”, as defined in 

this section. 

Dedicated truckvehicle has the same meaning as dedicated automobile as defined in 

49 U.S.C. 32901(a)(8). A dedicated automobile means an automobile that operates only 

on alternative fuels like E85 or natural gas, etc.

Dual fueled (multi-fuel or flexible-fuel truckvehicle) has the same meaning as dual 

fueled automobile as defined in 49 U.S.C. 32901(a)(9). For example, a vehicle that 

operates on gasoline and E85 or a plug-in hybrid electric vehicle is considered a dual 

fueled vehicle.

Electric vehicle means a vehicle that does not include an engine, and is powered 

solely by an external source of electricity and/or solar power. Note that this does not 

include electric hybrid or fuel-cell vehicles that use a chemical fuel such as gasoline, 
diesel fuel, or hydrogen. Electric vehicles may also be referred to as all-electric vehicles 

to distinguish them from hybrid vehicles.

Engine family has the meaning given in 40 CFR 1036.230. 

Family certification level (FCL) means the family certification limit for an engine 

family as defined in 40 CFR 1036.801. 

Family emission limit (FEL) means the family emission limit for a vehicle family as 

defined in 40 CFR 1037.801. 

Fuel cell electric vehicle means a motor vehicle propelled solely by an electric motor 

where energy for the motor is supplied by a fuel cell.

Fuel cell means an electrochemical cell that produces electricity via the noncombustion reaction of a consumable fuel, typically hydrogen.

Final-stage manufacturer has the meaning given in 49 CFR part 523567.3. 

Fleet in this part means all the heavy-duty trucksvehicles or engines within each of 

the regulatory sub-categories that are manufactured by a manufacturer in a particular 

model year and that are subject to fuel consumption standards under § 535.5. 

Fleet average fuel consumption is the calculated average fuel consumption 

performance value for a manufacturer’s fleet derived from the production weighted fuel 

consumption values of the unique vehicle configurations within each vehicle model type 

that makes up that manufacturer’s vehicle fleet in a given model year. In this part, the 

fleet average fuel consumption value is determined for each manufacturer’s fleet of 

heavy-duty pickup trucks and vans. 

Fleet average fuel consumption standard is the actual average fuel consumption 

standard for a manufacturer’s fleet derived from the production weighted fuel 

consumption standards of each unique vehicle configuration, based on payload, tow 

capacity and drive configuration (2, 4 or all-wheel drive), of the model types that makes 

up that manufacturer’s vehicle fleet in a given model year. In this part, the fleet average 

fuel consumption standard is determined for each manufacturer’s fleet of heavy-duty 

pickup trucks and vans. 

Fuel efficiency means the amount of work performed for each gallon of fuel 

consumed. 

Good engineering judgment has the meaning given in 40 CFR 1068.30. See 40 CFR 

1068.5 for the administrative process used to evaluate good engineering judgment.

Gross combination weight rating (GCWR) has the meaning given in 49 CFR part 523. 

Gross vehicle weight rating (GVWR) has the meaning given in 49 CFR part 523. 

Hearing Officer means a NHTSA employee who has been delegated the authority to 

assess civil penalties by the Administrator.

Heavy-duty truckvehicle has the meaning given in 49 CFR part 523.

Hybrid engine or hybrid powertrain means an engine or powertrain that includes 

energy storage features other than a conventional battery system or conventional 

flywheel. Supplemental electrical batteries and hydraulic accumulators are examples of 

hybrid energy storage systems Note that certain provisions in this part treat hybrid 

engines and powertrains intended for vehicles that include regenerative braking different 

than those intended for vehicles that do not include regenerative braking.

Hybrid vehicle means a vehicle that includes energy storage features (other than a

conventional battery system or conventional flywheel) in addition to an internal 

combustion engine or other engine using consumable chemical fuel. Supplemental 
electrical batteries and hydraulic accumulators are examples of hybrid energy storage 

systems Note that certain provisions in this part treat hybrid vehicles that include 

regenerative braking different than those that do not include regenerative braking.

Innovative technology means technology certified under 40 CFR part 1037.610.

Incomplete vehicle has the meaning given in 49 CFR 567.3523. For the purpose of 

this regulation, a manufacturer may request EPA and NHTSA to allow the certification of 

a vehicle as an incomplete vehicle if it manufactures the engine and sells the unassembled 

chassis components, provided it does not produce and sell the body components 

necessary to complete the vehicle. 

Liquefied petroleum gas (LPG) has the meaning given in 40 CFR 1036.801. 

Low rolling resistance tire means a tire on a vocational vehicle with a tire rolling 

resistance level (TRRL) of 7.7 kg/metric ton or lower, a steer tire on a tractor with a 

TRRL of 7.7 kg/metric ton or lower, or a drive tire on a tractor with a TRRL of 8.1 

kg/metric ton or lower. 

Model type has the meaning given in 40 CFR 600.002. 

Model year as it applies to engines means the manufacturer’s annual new model 

production period, except as restricted under this definition. It must include January 1 of 

the calendar year for which the model year is named, may not begin before January 2 of 

the previous calendar year, and it must end by December 31 of the named calendar year. 

Manufacturers may not adjust model years to circumvent or delay compliance with 

standards. 

Model year as it applies to vehicles means the manufacturer’s annual new model 

production period, except as restricted under this definition and 40 CFR part 85, subpart 

X. It must include January 1 of the calendar year for which the model year is named, 

may not begin before January 2 of the previous calendar year, and it must end by 

December 31 of the named calendar year. 

(1) The manufacturer who holds the certificate of conformity for the vehicle must 

assign the model year based on the date when its manufacturing operations are completed 

relative to its annual model year period. 

 (2) Unless a vehicle is being shipped to a secondary manufacturer that will hold the 

certificate of conformity, the model year must be assigned prior to introduction of the 

vehicle into U.S. commerce. The certifying manufacturer must redesignate the model 

year if it does not complete its manufacturing operations within the originally identified 

model year. A vehicle introduced into U.S. commerce without a model year is deemed to 

have a model year equal to the calendar year of its introduction into U.S. commerce 

unless the certifying manufacturer assigns a later date. 

Natural gas has the meaning given in 40 CFR 1036.801. Vehicles that use a pilotignited natural gas engine (which uses a small diesel fuel ignition system), are still 

considered natural gas vehicles.

NHTSA Enforcement means the NHTSA Associate Administrator for Enforcement, or 

his or her designee. 

Notice of violation means a notification of violation and preliminary assessment of 

penalty issued by the Chief Counsel to a party.

Party means the person alleged to have committed a violation of § 535.9, and 

includes manufacturers of vehicles and manufacturers of engines. 
Payload means in this part the resultant of subtracting the curb weight from the gross 

vehicle weight rating. 

Petroleum has the meaning given in 40 CFR 1036.801. 

Pickup truck has the meaning given in 49 CFR part 523. 

Plug-in hybrid electric vehicle (PHEV) means a hybrid electric vehicle that has the 

capability to charge the battery or batteries used for vehicle propulsion from an offvehicle electric source, such that the off-vehicle source cannot be connected to the 

vehicle while the vehicle is in motion.

Power take-off (PTO) means a secondary engine shaft or other system on a vehicle 

that provides substantial auxiliary power for purposes unrelated to vehicle propulsion or 

normal vehicle accessories such as air conditioning, power steering, and basic electrical 

accessories. A typical PTO uses a secondary shaft on the engine to transmit power to a 

hydraulic pump that powers auxiliary equipment such as a boom on a bucket truck. 

Regulatory category means each of the three types of heavy-duty trucks defined in 49 

CFR 523.6 and the heavy-duty engines defined in § 535.3.

Primary intended service class has the meaning for engines as specified in 40 CFR 

part 1036.140.

Rechargeable Energy Storage System (RESS) means the component(s) of a hybrid 

engine or vehicle that store recovered energy for later use, such as the battery system in a 

electric hybrid vehicle.

Regulatory category means each of the three types of heavy-duty vehicles defined in 

49 CFR 523.6 and the heavy-duty engines used in these heavy-duty vehicles.

Regulatory subcategory means the sub-groups in each regulatory category to which 

fuel consumption requirements apply, and are defined as follows: 

(1) Heavy-duty pick-up trucks and vans 

(2) Vocational light-heavy vehicles at or below 19,500 pounds GVWR. 

(3) Vocational medium-heavy vehicles above 19,500 pounds GVWR but at or below 

33,000 pounds GVWR. 

(4) Vocational heavy-heavy vehicles above 33,000 pounds GVWR. 

(5) Low roof day cab tractors with a GVWR above 26,000 pounds GVWR but at or 

below 33,000 pounds GVWR. 

(6) Mid roof day cab tractors with a GVWR above 26,000 pounds GVWR but at or 

below 33,000 pounds GVWR. 

(7) High roof day cab tractors with a GVWR above 26,000 pounds GVWR but at or 

below 33,000 pounds GVWR. 

(8) Low roof day cab tractors above 33,000 pounds GVWR. 

(9) Mid roof day cab tractors above 33,000 pounds GVWR. 

(10) High roof day cab tractors above 33,000 pounds GVWR. 

(11) Low roof sleeper cab tractors above 33,000 pounds GVWR. 

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

(13) High roof sleeper cab tractors above 33,000 pounds GVWR. 

(14) Compression-ignition light heavy-duty diesel engines in Class 2b to 5 

trucksvehicles with a GVWR above 8,500 pounds but at or below 19,500 pounds. 

(15) Compression-ignition medium heavy-duty diesel engines in Class 6 and 7 

vocational trucksvehicles with a GVWR above 19,500 but at or below 33,000 pounds. 
(16) Compression-ignition heavy heavy-duty diesel engines in Class 8 vocational 

trucksvehicles with a GVWR above 33,000 pounds. 

(17) Compression-ignition medium heavy-duty diesel engines in Class 7 tractors 

with a GVWR above 26,000 pounds but at or below 33,000 pounds. 

(18) Compression-ignition heavy heavy-duty diesel engines in Class 8 tractors with a 

GVWR above 33,000 pounds. 

(19) Spark ignition engines in Class 2b to 8 trucksvehicles with a GVWR above 

8,500 pounds. 

Roof height means the maximum height of a vehicle (rounded to the nearest inch), 

excluding narrow accessories such as exhaust pipes and antennas, but including any wide 

accessories such as roof fairings. Measure roof height of the vehicle configured to have 

its maximum height that will occur during actual use, with properly inflated tires and no 

driver, passengers, or cargo onboard. Determine the base roof height on fully inflated 

tires having a static loaded radius equal to the arithmetic mean of the largest and smallest 

static loaded radius of tires a manufacturer offers or a standard tire EPA approves. If a 

vehicle is equipped with an adjustable roof fairing, measure the roof height with the 

fairing in its lowest setting. Once the maximum height is determined, roof heights are 

divided into the following categories: 

(1A) Low-roof means relating to a vehicle with a roof height of 120 inches or less (2

(B) Mid-roof means relating to a vehicle with a roof height ofbetween 121 toand 147 

inches. 

(3C) High-roof means relating to a vehicle with a roof height of 148 inches or more. 

Service class group means a group of engine and vehicle averaging sets defined as 

follows: 

(A) Spark-ignition engines, light heavy-duty compression-ignition engines, light 

heavy-duty vocational vehicles and heavy-duty pickup trucks and vans. 

(B) Medium heavy-duty compression-ignition engines and medium heavy-duty 

vocational vehicles and tractors. 

(C) Heavy heavy-duty compression-ignition engines and heavy heavy-duty vocational 

vehicles and tractors. 

Sleeper cab means a type of truck cab that has a compartment behind the driver’s seat 

intended to be used by the driver for sleeping. This includes both cabs accessible from 

the driver’s compartment and those accessible from outside the vehicle. 

Spark-ignition engines means relating to a gasoline-fueled engine or any other type of 

engine with a spark plug (or other sparking device) and with operating characteristics 

significantly similar to the theoretical Otto combustion cycle. Spark-ignition engines 

usually use a throttle to regulate intake air flow to control power during normal operation. 

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. 

Test group means the multiple vehicle lines and model types that share critical 

emissions and fuel consumption related features and that are certified as a group by a 

common certificate of conformity issued by EPA and is used collectively with other test 

groups within an averaging set (aor regulatory subcategory) and is used by NHTSA for 

determining the fleet average fuel consumption. 
Tire rolling resistance level (TRRL) means a value with units of kg/metric ton that 

represents that rolling resistance of a tire configuration. TRRLs are used as inputs to the 

GEM model under 40 CFR part 1037.520. Note that a manufacturer may assign a value

higher than a measured rolling resistance of a tire configuration.

Towing capacity in this part is equal to the resultant of subtracting the gross vehicle 

weight rating from the gross combined weight rating.

Trade means to exchange fuel consumption credits, either as a buyer or a seller. 

Truck tractor has the meaning given in 49 CFR 571.3. This includes most heavyduty vehicles specifically designed for the primary purpose of pulling trailers, but does 

not include vehicles designed to carry other loads. For purposes of this definition “other 

loads” would not include loads carried in the cab, sleeper compartment, or toolboxes. 

Examples of vehicles that are similar to tractors but that are not tractors under this part 

include dromedary tractors, automobile haulers, straight trucks with trailers hitches, and 

tow trucks. 

U.S.-directed production volume means the number of vehicle units, subject to the 

requirements of this part, produced by a manufacturer for which the manufacturer has a 

reasonable assurance that sale was or will be made to ultimate purchasers in the United 

States. Useful life has the meaning given in 40 CFR 1037.801. 

Vehicle configuration has the meaning given in 40 CFR 600.002means a unique 

combination of vehicle hardware and calibration (related to measured or modeled 

emissions) within a vehicle family. Vehicles with hardware or software differences, but 

that have no hardware or software differences related to measured or modeled emissions 

or fuel consumption can be included in the same vehicle configuration. Note that 

vehicles with hardware or software differences related to measured or modeled emissions 

or fuel consumption are considered to be different configurations even if they have the 

same GEM inputs and FEL. Vehicles within a vehicle configuration differ only with 

respect to normal production variability or factors unrelated to measured or modeled 

emissions and fuel consumption for EPA and NHTSA.

Vehicle family has the meaning given in 40 CFR part 1037.230. 

Violation means a failure to comply with an applicable fuel consumption standard for a 

regulatory subcategory of vehicles or engines, after all flexibilities available under 

§ 535.7 are taken into account.

Vehicle service class has the meaning for vehicles as specified in the 40 CFR part 

1037.801. Vocational tractor has the meaning given in 40 CFR part 1037.630.

Zero emissions vehicle means an electric vehicle or a fuel cell vehicle.

§ 535.5 Standards. 

(a) Heavy-duty pickup trucks and vans. Each manufacturer of a fleet of heavy-duty 

pickup trucks and vans shall comply with the fuel consumption standards in this 

paragraph (a) expressed in gallons per 100 miles. If the manufacturer’s fleet includes 

conventional vehicles (gasoline, diesel and alternative fueled vehicles) and advanced 

technology vehicles (hybrids with regenerative braking, vehicles equipped with Rankinecycle engines, electric and fuel cell vehicles), it should divide its fleet into two separate 

fleets each with its own separate fleet average fuel consumption standard which a 

manufacturer must comply with the requirements of this paragraph (a). 
(1) For model years 2016 and later. Each manufacturer must comply with the fleet 

average standard derived from the unique vehicle configuration (payload, towing 

capacity and drive configuration)subconfiguration target standards (or groups of 

subconfigurations approved by EPA in accordance with 40 CFR part 1037.104) of the 

model types that make up the manufacturer’s fleet in a given model year. Each vehicle 

configurationsubconfiguration has a unique attribute-based target standard, defined by 

each group of vehicles having the same payload, towing capacity and whether the

vehicles are equipped with a 2-wheel or 4-wheel drive configuration. 

(2) Vehicle configurationSubconfiguration target standards. (i) Two 

alternatives exist for determining the vehicle configurationsubconfiguration target 

standards for model years 2016 and later. For each alternative, separate standards exist 

for compression-ignition and spark-ignition vehicles: 

(A) The first alternative allows manufacturers to determine a fixed fuel consumption 

standard that is constant over the model years; and 

(B) The second alternative allows manufacturers to determine standards that are 

phased-in gradually each year. 

(ii) Calculate the vehicle configurationsubconfiguration target standards as 

specified in this paragraph (a)(2)(ii), using the appropriate coefficients from Table 1 of 

this section to choosechoosing between the alternatives in paragraphs (a)(2)(i)(A) 

and (B) of this section. For electric or fuel cell heavy-duty trucksvehicles, use 

compression-ignition vehicle coefficients “c and d” and for hybrid (including plug-in 

hybrid), dedicated and dual-fueled trucksvehicles, use coefficients “c and d” appropriate 

for the engine type used. Round each standard to the nearest 0.101 gallons per 100 miles 

and specify all weights in pounds rounded to the nearest pound. Calculate the vehicle 

configurationsubconfiguration target standards using the following equation: 

 Vehicle ConfigurationSubconfiguration Target Standard (gallons per 100 

miles) = [c × (WF)] + d 

Where: 

WF = Work Factor = [0.75 x (Payload Capacity + Xwd)] + [0.25 x Towing Capacity]

Xwd = 4wd Adjustment = 500 lbs if the vehicle group is equipped with 4wd and allwheel drive, otherwise equals 0 lbs for 2wd. 

Payload Capacity = GVWR (lbs) - Curb Weight (lbs) (for each vehicle group) 

Towing Capacity = GCWR (lbs) - GVWR (lbs) (for each vehicle group) 

 

Table 1– Equation Coefficients for Vehicle ConfigurationSubconfiguration Target Standards 

Alternative 1 – Fixed Target Standards

Compression-ignition Vehicle Coefficients for Model Years 2016 and later 

Model Year c d 

2016 -– 2018 0.000432 3.33 

2019 and later 0.000409 3.14

Spark-ignition Vehicle Coefficients for Model Years 2016 and later

2016 -- 2018 0.000513 3.96

2019 and later 0.000495 3.81 
Alternative 2 – Phased-in Target Standards

Compression-ignition Vehicle Coefficients for Model Years 2016 and later 

Model Year c d 

2016 0.000452 3.48 

2017 0.000437 3.37 

2018 and later 0.000409 3.14 

Spark-ignition Vehicle Coefficients for Model Years 2016 and later 

2016 0.000528 4.07 

2017 0.000518 3.98 

2018 and later 0.000495 3.18 

 

(3) Fleet average fuel consumption standard. (i) Calculate each manufacturer’s fleet 

average fuel consumption standard fromfor conventional and advanced technology fleets 

separately based on the vehicle configurationsubconfiguration target standards specified 

in paragraph (a)(2) of this section, weighted to production volumes and averaged using 

the following equation combining all the applicable vehicles in a manufacturer’s U.S. 

directed fleet (compression-ignition and, spark-ignition and advanced technology 

vehicles) for a given model year, rounded to the nearest 0.101 gallons per 100 miles: 

[ ]

∑[ ]

∑ ×

=

i

i i

Volume

Subconfiguration Target Standard Volume

Fleet AverageStandard

Where: 

Vehicle ConfigurationSubconfiguration Target Standardi = fuel consumption standard 

for each group of vehicles with same payload, towing capacity and drive configuration.

(gallons per 100 miles).

Volumei = production volume of each unique vehicle configurationsubconfiguration

of a model type based upon payload, towing capacity and drive configuration. 

(A) A manufacturer may group together subconfigurations that have the same test 

weight (ETW), GVWR, and GCWR. Calculate work factor and target value assuming a 

curb weight equal to two times ETW minus GVWR. 

(B) A manufacturer may group together other subconfigurations if it uses the lowest 

target value calculated for any of the subconfigurations.

(C) The fleet average shall also be derived in accordance with 40 CFR 86.1865-12 

and 40 CFR part 1037.104(d).

(ii) A manufacturer complies with the requirements of this part, if at the end of the 

model year, if it provides reports, as specified in § 535.8, to the Administrator by the 

required deadlines and meets one of the following conditions: 

(A) The manufacturer’s fleet average performance, as determined in § 535.6, is less 

than the fleet average standard; or 

(B) The manufacturer uses one or more of the credit flexibilities provided under 

NHTSA’s Averaging, Banking and Trading Program, as specified in § 535.7, to comply 

with standards; and. 

(iii) Manufacturers must select an alternative for vehicle 

configurationsubconfiguration target standards at the same time they submit the model 

year 2016 Pre-Model year Report, specified in § 535.8. Once selected, the decision 
cannot be reversed and the manufacturer must continue to comply with the same 

alternative for subsequent model years. 

(iv) A manufacturer failing to comply with the provisions specified in paragraph 

(a)(3)(ii) of this section is liable to pay civil penalties in accordance with § 535.9. 

(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. 

(ii) A manufacturer must declare its intent to voluntarily comply with fuel 

consumption standards at the same time it submits a Pre-Model Report, prior to the 

compliance model year beginning as specified in § 535.8; and, once selected, the decision 

cannot be reversed and the manufacturer must continue to comply for each subsequent 

model year. for all the vehicles and engines it manufactures in each regulatory category 

for a given model year.

(iii) Calculate separate vehicle configurationsubconfiguration target standards for 

compression-ignition and spark-ignition vehicles for model years 2013 through 2015 

using the equation in paragraph (a)(2)(ii) in this section, substituting the appropriate 

values for the coefficients in Table 2 of this section as appropriate. 

 

Table 2 – Voluntary Compliance Equation Coefficients for Vehicle Fuel Consumption Standards 

Compression-ignition Vehicle Coefficients 

for Voluntary Compliance in Model Years 2013 through 2015

Model Year c d 

2013 and 14 0.000470 3.61 

2015 0.000466 3.60 

Spark-ignition Vehicle Coefficients 

for Voluntary Compliance in Model Years 2013 through 2015

Model Year c d 

2013 and 14 0.000542 4.17 

2015 0.000539 4.15 

 

(iv) Calculate the fleet average fuel consumption standards for model years 2013 

through 2015 using the equation in paragraph (a)(3) of this section. 

(5) Cab-Exclusion of vehicles not certified as complete vehicles. The provisions of this 

section apply to applicable cab-complete vehicles in the same manner as they apply to 

complete vehicles. Calculate the unique vehicle configuration target standards based on 

the same values that would § 535.5(a) do not apply for the most similar complete vehicle 

to the cab-complete vehicle. 

(6) Low volume exclusion. A manufacturer may exclude a limited number of 

vehicles from the standards of this section. The number of excluded vehicles may not 

exceed 2000 in any model year, unless the total production of vehicles in this category for 

that model year is greater than 100,000 and the excluded vehicles vehicles that are not 

more than 2.00 percent of the manufacturer’s total production of vehicles in this 

subcategory for any model year. For example, a vehicle manufacturer producing 200,000 

vehicles in a given model year could exclude up to 4,000 vehicles under this paragraph 
(a)(6). The chassis-certified with respect to EPA’s criteria pollutant test procedure in 40 

CFR part 86, subpart S. Any chassis-certified vehicles must comply with the vehicle 

standards and requirements of paragraph § 535.5(b) of this section apply forand the 

excluded vehicles. Theengine standards in paragraph of § 535.5(d) of this section also 

apply for engines used in these excluded vehicles. Manufacturers must submit 

information in their Pre-Certification Compliance Report, as specified in § 535.8, 

describing how they intend to use the provisions of this paragraph (a)(6). If the chassis 

manufacturer vehicles. A vehicle manufacturer choosing to comply with this paragraph 

and that is not the engine manufacturer, the chassis manufacturer must is required to

notify the engine manufacturer, as required by EPA in 40 CFR 1037.104,manufacturers

that their engines are subject to the requirements of paragraph 535.5(d) of this section and 

are intended forthat it intends to use their engines in excluded vehicles. 

(6) Optional certification under this section. Manufacturers may certify any 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 

same testing and standard that applies to a comparable complete sister vehicles as 

determined in accordance in 40 CFR part 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. 

(7) Loose engines. This paragraph applies for spark-ignition engines identical to 

engines used in vehicles certified to the standards of this section § 535.5(a), where 

manufacturers sell such engines as loose engines or installed in incomplete vehicles that 

are not cab-complete vehicles in accordance with 40 CFR part 1037.150(m). A 

manufacturer’s engines are deemed to have fuel consumption target values and test 

results based upon the complete vehicle in the applicable test group with the highest 

equivalent test weight in accordance with 40 CFR part 1037.150(m). The fuel 

consumption subconfiguration standard for a loose engines equals the test group result of 

the complete vehicle as specified in 40 CFR 1037.150(m)(6) multiplied by 1.10 and 

rounded to the nearest 0.01 gallon per 100 miles. The U.S.-directed production volume 

of engines manufactured for sale as loose engines or installed in incomplete heavy-duty 

vehicles that are not cab-complete vehicles in any given model year may not exceed ten 

percent of the total U.S-directed production volume of engines of that design that the 

manufacturer produces for heavy-duty applications for that model year, including engines 

the manufacturer produces for complete vehicles, cab-complete vehicles, and other 

incomplete vehicles. The total number of engines a manufacturer may certify under this 

paragraph (7), of all engine designs, may not exceed 15,000 in any model year as 

specified in 40 CFR part 1037.150(m). Engines produced in excess of the number cannot

be certified to the standard in this paragraph (7). 

 (b) Heavy-duty vocational trucksvehicles. Each chassis manufacturer of heavy-duty 

vocational trucksvehicles shall comply with the fuel consumption standards in this 

paragraph (b) expressed in gallons per 1000 ton-miles. Manufacturers of engines used in 

heavy-duty vocational vehicles shall comply with the standards in paragraph (d) of this 

section. 

(1) For model years 2016 and later. Each chassis manufacturer of heavy-duty 

vocational trucksvehicles must comply with the fuel consumption standards in paragraph 

(b)(3) of this section. 
(i) The heavy-duty vocational truckvehicle chassis category is subdivided by GVWR 

into three regulatory subcategories as defined in § 535.4, each with its own assigned 

standard. 

(ii) For purposes of certifying vehicles to fuel consumption standards, manufacturers 

must divide their product lines into vehicle families that have similar emissions and fuel 

consumption features, as specified by EPA in 40 CFR part 1037, subpart C, and these

families will be subject to the applicable standards. Each vehicle family is limited to a 

single model year. 

(iii) Standards for heavy-duty vocational truck engines are given in paragraph (d) of this 

section. 

(iv) A manufacturer complies with the requirements of this part, if at the end 

of the model year, it provides reports,information as specified in § 535.8, to the 

Administrator by the required deadlines and meets one of the following conditions:

(A) The manufacturer’s fuel consumption performance for each vehicle family, as 

determined in § 535.6, is lower than the applicable standard; or 

(B) The manufacturer uses one or more of the credit flexibilities provided under 

NHTSA’s Averaging, Banking and Trading Program, specified in § 535.7, to comply 

with standards; and. 

 (v(iv) A manufacturer failing to comply with the provisions specified in paragraph 

(b)(1)(iviii) of this section is liable to pay civil penalties in accordance with § 535.9. 

(2) Voluntary compliance.(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 each regulatory 

subcategory.. For example, a manufacturer may choose to comply early in order to begin 

accumulating credits through over-compliance with the applicable standard.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. 

(ii) A manufacturer must declare its intent to voluntarily comply with fuel 

consumption standards and identify its plans to comply before it submits theits first 

application for a certificate of conformity for the respective model year as specified in 

§ 535.8; and, once selected, the decision cannot be reversed and the manufacturer must

continue to comply for each subsequent model year. for all the vehicles and engines it 

manufacturers in each regulatory category for a given model year.

(3) Regulatory subcategory standards. The fuel consumption standards for heavyduty vocational trucksvehicles are given in the following table: 

Table 3 – Heavy-Duty Vocational TruckVehicle Fuel Consumption Standards 
Fuel Consumption Mandatory Standards (gallons per 1000 ton-miles) 

Effective for Model Years 2017 and later

Effective for Model Years 2017 and later

Regulatory 

Subcategories 

Light Heavy Vehicles 

Class 2b – 5 

Medium Heavy 

Vehicles Class 6 - 7 

Heavy Heavy Vehicles 

Class 8 

Fuel Consumption 

Standard 

 36.47 22.1 21.8 

Effective for Model Years 2016

Fuel Consumption 

Standard

38.1 23.0 22.2

Fuel Consumption Voluntary Standards (gallons per 1000 ton-miles) 

Effective for Model Years 2013 to 20165

Regulatory 

Subcategories 

Light Heavy Vehicles 

Class 2b – 5 

Medium Heavy 

Vehicles Class 6 - 7 

Heavy Heavy Vehicles 

Class 8 

Fuel Consumption 

Standard 

37.838.1 22.923.0 22.2 

(4) A manufacturer may optionally certify a vocational vehicle to the standards and 

useful life applicable to a higher vehicle service class (or regulatory subcategory changes 

such as complying with the heavy heavy-duty standard instead of medium heavy-duty 

standard), provided the manufacturer does not generate credits with the vehicle. If a 

manufacturer includes smaller vehicles in a credit-generating subfamily (with an FEL 

below the standard), exclude their production volume from the credit calculation.

(5) Heavy-duty vocational vehicles including vocational tractors meeting the off-road 

criteria in 49 CFR part 523.2 are exempted from the requirements in paragraph (b) of this 

section but the engines in these vehicles must meet the requirements of paragraph (d) of 

this section. 

(c) Truck tractors. Each manufacturer of truck tractors, except vocational tractors, 

with a GVWR above 26,000 pounds shall comply with the fuel consumption standards in 

this paragraph (c) expressed in gallons per 1000 ton-miles. 

(1) For model years 2016 and later. Each manufacturer of truck tractors must 

comply with the fuel consumption standards in paragraph (c)(3) of this section. 

(i) The truck tractor category is subdivided by roof height and cab design into nine 

regulatory subcategories as shown in Table 4 of this section, each with its own assigned 

standard. 

(ii) For purposes of certifying vehicles to fuel consumption standards, manufacturers 

must divide their product lines into vehicles families that have similar emissions and fuel 

consumption features, as specified by EPA in 40 CFR part 1037, subpart C, and these

families will be subject to the applicable standards. Each vehicle family is limited to a 

single model year. 

(iii) Standards for truck tractor engines are given in paragraph (d) of this section. 

(iv) A manufacturer complies with the requirements of this part, if at the end of the 

model year, it provides reports, as specified in § 535.8, to the Administrator by the 

required deadlines and meets one of the following conditions: 

(A) The manufacturer’s fuel consumption performance for each vehicle family, as 

determined in § 535.6, is lower than the applicable standard; or 

Formatted Table

Formatted Table

Formatted Table
(B) The manufacturer uses one or more of the credit flexibilities provided under 

NHTSA’s Averaging, Banking and Trading Program, specified in § 535.7, to comply 

with standards; and. 

(v) A manufacturer failing to comply with the provisions specified in paragraph 

(c)(1)(iv) of this section is liable to pay civil penalties in accordance with § 535.9. 

(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 each regulatory subcategory.. For example, a 

manufacturer may choose to comply early in order to begin accumulating credits through 

over-compliance with the applicable standard.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. 

(ii) A manufacturer must declare its intent to voluntarily comply with fuel 

consumption standards and identify its plans to comply before it submits theits first 

application for a certificate of conformity for the respective model year as specified in 

§ 535.8; and, once selected, the decision cannot be reversed and the manufacturer must 

continue to comply for each subsequent model year. for all the vehicles and engines it 

manufacturers in each regulatory category for a given model year.

(3) Regulatory subcategory standards. The fuel consumption standards for truck 

tractors, except for vocational tractors, are given in the following table: 

Table 4 – Truck Tractor Fuel Consumption Standards

Fuel Consumption Mandatory Standards (gallons per 1000 ton-miles) 

Effective for Model Years 2017 and later 

Regulatory 

Subcategories 

Day Cab Sleeper Cab 

Class 7 Class 8 Class 8 

Low Roof 10.32 7.8 6.5 

Mid Roof 11.3 8.4 7.2

High Roof 11.68 8.67 7.01

Effective for Model Years 2016

Low Roof 10.5 8.0 6.7

Mid Roof 11.7 8.7 7.4

High Roof 12.2 9.0 7.3

Fuel Consumption Voluntary Standards (gallons per 1000 ton-miles) 

Effective for Model Years 2013 to 20165

Regulatory 

Subcategories 

Day Cab Sleeper Cab 

Class 7 Class 8 Class 8 

Low Roof 10.5 8.0 6.67

Mid Roof 11.67 8.7 7.4 

High Roof 12.02 8.9.0 7.23

(4) A manufacturer may optionally certify a tractor to the standards and useful life 

applicable to a higher vehicle service class (or regulatory subcategory changes such as 

complying with the Class 8 day-cab tractor standard instead of Class 7 day-cab tractor), 

provided the manufacturer does not generate credits with the vehicle. If a manufacturer 

includes smaller vehicles in a credit-generating subfamily (with an FEL below the 

standard), exclude their production volume from the credit calculation.

Formatted Table
(5) Tractors meeting the definition of vocational tractors in 49 CFR part 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 

part 1037.205 and 40 CFR part 1037.610, a manufacturer must comply with the tractor 

fuel consumption standards in paragraph (3) of this section. 

(d) Heavy-duty engines. Each manufacturer of heavy-duty engines shall comply with 

the fuel consumption standards in this paragraph (d) expressed in gallons per 100 brakehorsepower-hours. Each engine must be certified to the primary intended service class 

that it is designed for in accordance with 40 CFR part 1036.108; 

(1) For model years 2017 and later compression-ignition engines and for model 

years 2016 and later spark-ignition engines. Each manufacturer must comply with the 

fuel consumption standard in paragraph (d)(3) of this section. 

(i) The heavy-duty engine regulatory category is divided into six regulatory 

subcategories, five compression-ignition subcategories and one spark-ignition 

subcategory, as shown in Table 5 of this section. 

(ii) Separate standards exist for engines manufactured for use in heavy-duty 

vocational trucksvehicles and in truck tractors. 

(iii) For purposes of certifying engines to fuel consumption standards, manufacturers 

must divide their product lines into engine families that have similar fuel consumption 

features, as specified by EPA in 40 CFR part 1036, subpart C, and these families will be 

subject to the same standards. Each engine family is limited to a single model year. 

(iv) A manufacturer complies with the requirements of this part, if at the end of the 

model year, it provides reports, as specified in § 535.8, to the Administrator by the 

required deadlines and meets one of the following conditions: 

(A) The manufacturer’s fuel consumption performance of each engine family as 

determined in § 535.6 is less than the applicable standard; or 

(B) The manufacturer uses one or more of the flexibilities provided under NHTSA’s 

Averaging, Banking and Trading Program, specified in § 535.7, to comply with 

standards; and. 

(v) A manufacturer failing to comply with the provisions specified in paragraph 

(d)(1)(iv) of this section is liable to pay civil penalties in accordance with § 535.9. 

(2) Voluntary compliance. (i) For model years 2013 through 2016 for compressionignition engines, and for model years 2013 throughyear 2015 for spark-ignition engines, a 

manufacturer may choose voluntarily to comply with the fuel consumption standards 

provided in paragraph (d)(3) ), (d)(4) and (5) of this section. For example, a 

manufacturer may choose to comply early in order to begin accumulating credits through 

over-compliance with anthe applicable standard. 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 in model year 

2013 the manufacturer may comply with individual engine families as specified in 40 

CFR part 1036.150(a)(2). 

(ii) A manufacturer must declare its intent to voluntarily comply with fuel 

consumption standards and identify its plans to comply before it submits theits first 
application for a certificate of conformity for the respective, model year as specified in 

§ 535.8; and, once selected, the decision cannot be reversed and the manufacturer must

continue to comply for each subsequent model year. for all the vehicles and engines it 

manufacturers in each regulatory category for a given model year. 

 (3) Regulatory subcategory standards. The fuel consumption standards for heavyduty engines are given in the following: 

Table 5 – Primary Heavy-Duty Engine Standards 

(4) Alternate Fuel Consumptionsubcategory standards based on model year 2011. 

The alternative fuel consumption standards for heavy-duty compression-ignition engines.

are as follows: 

(i) Manufacturers entering the voluntary program in model years 2014 through 2016, 

may choose to certify compression-ignition enginesengine families unable to meet 

standards provided in paragraph (3) of this part to the alternative fuel consumption 

standards of this section instead of the fuel consumption 2 standards in 3d. However,. 

(ii) Manufacturers may not certify engines to these alternate standards if they are part 

of an averaging set in which they carry a balance of banked credits. Manufacturers may 

submit applications for certifications before using up banked credits in the 

averaging set, but such certificates will not become effective until they have used up 

(or retired) banked credits in the averaging set. For purposes of this section, 

manufacturers are deemed to carry credits in an averaging set if they carry credits from 

advance technology that are allowed to be used in that averaging set. in accordance with 

Fuel Consumption Mandatory Standards (gallons per100 bhp-hr) 

Regulatory 

Subcategory 

Light Heavy-Duty 

CompressionIgnition Engine 

Medium Heavy-Duty 

Compression-Ignition 

Engine 

Heavy Heavy-Duty 

Compression-Ignition 

Engine 

Spark-ignition 

Engines 

Truck 

Application 

Vocational Vocational Tractor Vocational Tractor All 

Effective Model 

Years 

2017 and later 2016 and later 

Fuel 

Consumption 

Standard 

5.66 5.66 4.78 5.45 4.52 7.06 

Fuel Consumption Standards for Voluntary Compliance (gallons per100 bhp-hr) 

Regulatory 

Subcategory 

Light Heavy-Duty 

DieselCompressi

on-Ignition

Engine 

Medium Heavy-Duty 

Diesel CompressionIgnition Engine 

Heavy Heavy-Duty 

Diesel CompressionIgnition Engine 

Spark-ignition 

Engine 

Truck 

Application 

Vocational Vocational Tractor Vocational Tractor All 

Effective Model 

Years 

2013 through 2016 2013 through 

2015 

Voluntary Fuel 

Consumption 

Standard 

5.89 5.89 4.93 5.57 4.67 7.06 

Formatted Table

Formatted Table
§ 535.7(d)(12).

(iii) The emission standards of this section are determined as specified in EPA 40 

CFR subpart G part 1036.620, sections (a) through (e).c) and should be converted to 

equivalent fuel consumption values.

(5) Alternate Phase-In Standards. Manufacturers may choose to selecthave the 

Alternate Phase In Standards described in this section. Where a manufacturer 

certifies all its model year 2013 option to comply with EPA emissions standards for 

compression-ignition engines within a given service class to the applicable alternate 

standards of this paragraph (insert number), its engines withinusing an alternative 

phase-in schedule that service class are subject tocorrelates with the EPA OBD 

standards. If a manufacturer chooses to use the alternative phase-in schedule for meeting 

EPA standards and optionally chooses to comply early with the NHTSA fuel

consumption program, it must use the same phase-in schedule beginning in model year 

2013 for fuel consumption standards and must remain in the program for each model year 

thereafter. The fuel consumption standard for each model year of the alternative phase-in 

schedule is provided in Table 6 of this paragraph for model years 2013 through 2016. 

section. Note that engines certified to these standards are not eligible for early credits 

under paragraph (insert number) of this section§ 535.7.

Table 6 – Alternative Phase-in Compression Ignition Engine Standards

Tractors LHD Engines MHD Engines HHD Engines

Model Years2013-2015 NA 5.03gals/100 hp-rhr 4.76 gals./100 hp-hr

Model Years 2016 and 

later†

NA 4.78 gals./100 hp-hr 4.52 gals/100 hp-hr

Vocational LHD Engines MHD Engines HHD Engines

Model Years 2013-2015 6.07gals/100hp-hr 6.07 gals/100 hp-hr 5.67 gals/100 hp-hr

Model Years 2016 and 

later†

5.66 gals/100 hp-hr 5.66 gals/100 hp-hr 5.45 gals/100 hp-hr

† Note: these alternate standards for 2016 and later are the same as the otherwise 

applicable standards for 2017 and later.

§ 535.6 Measurement and calculation procedures. 

(a) Manufacturers must calculate Heavy-duty pickup trucks and vans. This section 

describes the testing a manufacturer must perform for each model year and the method 

for determining the fleet average fuel consumption of heavy-duty pickup trucks and vans 

that are manufactured in a model year and compare the value to performance to show 

compliance with the fleet average fuel consumption standard, determined in § for heavyduty pickup trucks and vans in § 535.5, as follows:(a). 

(1) Manufacturers must calculate the fleet average CO2 performance for production 

weighted test results for the test groups that make up the manufacturer’s fleet of heavyduty pickup trucks and vans as specified in § 1037.104For each model year, the heavyduty pickup trucks and vans selected by a manufacturer to comply with fuel consumption 

standards in § 535.5(a) must be used to determine the manufacturer’s fleet average fuel 

consumption performance. If the manufacturer’s fleet includes conventional and 

Formatted Table

Formatted Table
advanced technology heavy-duty pickup trucks and vans, the fleet should be sub-divided 

into two separate vehicle fleets, with all of the conventional vehicles in one fleet and all 

of the advanced technology vehicles in the other fleet. 

(i) (2) Vehicles in each fleet should be divided into test groups are selected or 

subconfigurations according to EPA in 40 CFR part 1037.104 and 40 CFR part 86, 

subpart S. 

(ii) Determine(3) Test and measure the CO2 performanceemissions test results for 

each the selected vehicles and determine the CO2 emissions test group result, in grams 

per mile, according to EPA in accordance with 40 CFR Part 86 and § 1037.104., subpart 

S. 

(2) Manufacturers must calculate an(i) Perform exhaust testing on vehicles fueled 

by conventional and alternative fuels, including dedicated and dual fueled (multi-fueled 

and flexible fueled) vehicles and measure the CO2 emissions test result.

(ii) Adjust the CO2 emissions test result of dual fueled vehicles using a weighted 

average of your emission results as specified in 40 CFR 600.510–12(k) for light-duty 

trucks. 

(iii) All electric vehicles are deemed to have zero emissions of CO2, CH4, and N2O. 

No emission testing is required for such electric vehicles. Assign the fuel consumption 

test group result to a value of zero gallons per 100 miles in paragraph (4) of this section. 

(iv) Test cab-complete and incomplete vehicles using the applicable complete sister 

vehicles as determined in 40 CFR part 1037.104(g).

(v) Test loose engines using applicable complete vehicles as determined in 40 CFR 

part 1037.104(h).

(vi) Manufacturers can choose to analytically derive CO2 emission rates (ADCs) for 

test groups or subconfigurations. Calculate the ADCs for test groups or 

subconfigurations in accordance with 40 CFR part 1037.104(g). 

(4) Calculate equivalent fleet average fuel consumption valuetest group results, in 

gallons per 100 miles, from the average CO2 performance of the fleetCO2 emissions test 

group results, in grams per miles, using the following equations below.and round to the 

nearest 0.01 gallon per 100 miles. 

(i) Diesel Fuel. 

Fleet Average CO2 Performance Value (grams per miles(i) Calculate the equivalent 

fuel consumption test group results as follows for compression-ignition vehicles and 

alternative fuel compression-ignition vehicles. CO2 emissions test group result (grams 

per mile) / 10,180 grams per gallon of diesel fuel) x (102) = Fleet Average= Fuel 

consumption Value oftest group result (gallons per 100 mile).

(ii) Calculate the Fleetequivalent fuel consumption test group results as follows for sparkignition vehicles and alternative fuel spark-ignition vehicles. CO2 emissions test group 

result (grams per 100 miles per gallon)

(ii) Gasoline Fuel.

Fleet Average CO2 Performance Value (grams per milesmile) / 8,877 grams per 

gallon of gasoline fuel) x (102) = Fleet Average= Fuel consumption Value of the Fleet 

(gramstest group result (gallons per 100 miles per gallon)mile).

(iii) Alternative Fuels. 

Fleet Average CO2 Performance Value (grams per miles) / equivalency factor in grams 

per gallon of gasoline fuel) x (102) = Fleet Average Fuel Consumption Value of5) 
Calculate the fleet (gramsaverage fuel consumption result, in gallons per 100 miles per 

gallon)

Where, from the equivalency factors for each alternative fuel is as follows:

Fuel Type Grams of CO2 per gallon of alternative 

fuel

NA natural gas 340

Liquefied natural gas 290

Electricity 0

Biodiesel (soybean) 300

Ethanol (corn or corn stover) 380

(2) The manufacturer must submit equivalent fuel consumption values for each test group

results and its fleet to NHTSA and EPA in accordance with § 535.8. After each model 

year ends, EPA will verifyround the manufacturer’s fuel economy levels for each test 

group and the fleet using testing and verify the equivalency of fuel consumption values. 

EPA will prepare a final report with all the verified values and submit the report to the 

NHTSA within three months of receiving the manufacturer’s end-of-the-year and final 

year reports as specified in § 535.8.

(3) NHTSA will use the verified values provided by EPA in determining compliance 

with fuel consumption standards in § 535.5 and for verifying end of yearresult to the 

nearest 0.01 gallon per 100 miles. Calculate the fleet average fuel consumption credits 

under its ABT program specified in § 535.7. result using the following equation.

(b) The manufacturer must calculate the

[ ]

∑[ ]

∑ ×

=

i

i i

Volume

Fuel Consumption Test Group Result Volume

Fleet Average Fuel Consumption

 Where:

Fuel Consumption Test Group Resulti = fuel consumption valueperformance for each 

vehicle family that makes up itstest group as defined in § 523.4.

Volumei = production volume of each test group.

(6) Compare the fleet of heavy-duty vocational trucks in each regulatory subcategory and 

compare the results to the applicableaverage fuel consumption standard, determined in 

§ 535.5, as follows:

(1) Manufacturers must determine the family emission limit (FEL) for each vocational 

truck vehicle family in accordance with 40 CFR part 1037, subpart F. 

(i) Determine the vehicle families in accordance with 40 CFR 1037.230.

(ii) Use the attribute values in the GEM Model to determine the to the fleet average fuel 

consumption values, in gallons per 1000 ton-miles, for each vehicle type within the test 

groups and the FEL for each vehicle family as specified in 40 CFR 1037.241 and 40 CFR 

part 1037, subpart F.

(iii) Round eachperformance. The fleet average fuel consumption valueperformance 

must be less than or equal to the nearest 0.1 gallons per 1000 ton-miles.

(2) The manufacturer must submit the vehicle type fuel consumption values and the FELs 

for vehicle families to NHTSA and EPA in accordance with § 535.8. After each model 

year ends, EPA will verify the manufacturer’s CO2 family emission limits through 

modeling and verify the equivalent fuel consumption values. EPA will prepare a final 

report with all the verified values and submit the report to the NHTSA after receiving the 

manufacturer’s end-of-the-year and final year reports as specified in § 535.8.
(c) Manufacturers must calculate the fuel consumption value for each vehicle family 

that makes up the manufacturer’s fleet of truck tractors in each regulatory subcategory 

and compare the results to the applicable fuel consumption standard, determined to 

comply with standards in § 535.5, as follows:(a). 

(1) Manufacturers must determine the family emission limit (FEL) for the truck 

tractor vehicle family (b) Heavy-duty vocational vehicles and tractors. This section 

describes the testing a manufacturer must perform and the method for determining fuel 

consumption performance to show compliance with the fuel consumption standards for 

vocational vehicles and tractors in § 535.5(b) and (c). 

(1) Select vehicles and vehicle family configurations to test as specified in 40 CFR 

part 1037.230 for vehicles that make up each of the manufacture’s regulatory 

subcategories of vocational vehicles and tractors.

(2) Determine the CO2 emissions and fuel consumption results for all vehicle chassis 

(conventional, alternative fueled and advanced technology vehicles) using the 

Greenhouse Emissions Model (GEM) in accordance with 40 CFR part 1037 subpart F. 

Vocational vehicles and tractor chassis are modeled using the following inputs in the 

GEM model. All seven of the following inputs apply for sleeper cab tractors, while some 

do not apply for vocational vehicles and other tractor regulatory subcategories:

(i) Identification of vehicles using regulatory subcategories (such as “Class 8 

Combination – Sleeper Cab – High Roof”).

(ii) Coefficient of aerodynamic drag in accordance with 40 CFR part 1037.520 and 40 

CFR part 1037.521. Do not use for vocational vehicles.

(iii) Steer tire rolling resistance for low rolling resistance tires in accordance with 40 

CFR part 1037.520 and 40 CFR part 1037.650.

(iv) Drive tire rolling resistance for low rolling resistance tires in accordance with 40 

CFR part 1037.520 and 40 CFR part 1037.650.

(v) Vehicle speed limit as governed by vehicles speed limiters in accordance with 40 

CFR part 1037, subpart F.520 and 40 CFR part 1037.640. Do not use for vocational 

vehicles. 

(i) Determine the vehicle families(vi) Vehicle weight reduction as provided in 

accordance with 40 CFR part 1037.520. Do not use for vocational vehicles.

(vii) Extended idle reduction credit using automatic engine shutdown systems in 

accordance with 40 CFR part 1037.230.

(ii) Use the attribute values in the GEM Model to determine the fuel 

consumption values, in gallons per 1000 ton-mile, for each vehicle type within 

the test groups520 and the FEL40 CFR part 1037.660. Do not use for each vehicle 

family as specified in 40 CFR 1037.241 and 40 CFR part 1037, subpart F. 

vehicles other than Class 8 sleeper cabs.

(iii) Round each fuel consumption value to the nearest 0.1 gallons per 1000 ton-miles.

(2) The manufacturer must submit the vehicle type fuel consumption values and the FELs 

for vehicle families to NHTSA and EPA in accordance with § 535.8. After each model 

year ends, EPA will verify the manufacturer’s CO2 family emission limit through 

modeling and verify the equivalent fuel consumption values. EPA will prepare a final 

report with all the verified values and submit the report to the NHTSA after receiving the 

manufacturer’s end-of-the-year and final year reports as specified in § 535.8.

(d) The manufacturer must calculate the (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 and expressed to the nearest 0.1 

gallons per 1000 ton-mile. For families containing multiple subfamilies, identify the 

FELs for each subfamily. 

(4) The above sections address vocational vehicle and tractor chassis testing only. 

Engine performance and the advanced technologies equipped on vocational vehicles and 

tractors are tested separately as follows:

 (i) Vocational vehicle and tractor engine test results for conventional and alternative 

fueled vehicles are determined in accordance with § 535.6(c). 

 (ii) Improvements for advanced technologies are determined as follows:

 (A) Test hybrid vehicles with power take-off in accordance with 40 CFR part 

1037.525 and vehicles with post-transmission hybrid systems in accordance with 40 CFR 

part 1037.550. 

(B) All electric vehicles are deemed to have zero CO2 emissions and fuel 

consumption. No emission testing is required for such electric vehicles. Assign the 

vehicle family with a fuel consumption FEL result to a value of zero gallons per 1000-ton 

miles in paragraph (3) of this section. 

 (c) Heavy-duty engines. This section describes the testing a manufacturer must 

perform and the method for determining fuel consumption value for each engine 

familyperformance to show compliance with the fuel consumption standards for engines 

in § 535.5(d). Each engine must be tested to the primary intended service class that it is 

designed for in accordance with 40 CFR part 1036.108

(1) Select emission-data engines and engine family configurations to test as specified 

in 40 CFR part 86 and 40 CFR part 1036 subpart C for engines installed in vehicles that 

make up each of the manufacture’s fleet of heavy-duty trucks in each regulatory 

subcategory and compare.

(2) Test the resultsCO2 emissions for each emissions-data engine subject to the 

applicable fuel consumption standard, determined in § 535.5, as follows:standards in § 

535.5(d) using the procedures and equipment specified in 40 CFR part 1036 subpart F. 

Measure the CO2 emissions in grams per bhp-hr as specified in 40 CFR part 86, subpart 

N and 40 CFR Part 1036 subpart C. 

(1)i) Perform exhaust testing on each fuel type for conventional, dedicated, dual fuel 

(multi-fuel, and flexible fuel) vehicles and measure the CO2 emissions level.

(ii) Adjust the CO2 emissions result of dual fueled vehicles using a weighted average 

of the demonstrated emission results as specified in 40 CFR part 1036.225. If EPA 

disapproves a manufacturer’s dual fuel vehicle demonstrated use submission, NHTSA 

will require the manufacturer mustto only use the test results with 100 percent 

conventional fuel to determine the CO2 emission valuesfuel consumption of the engine. 

(iii) All electric vehicles are deemed to have zero emissions of CO2 and zero fuel 

consumption. No emission or fuel consumption testing is required for such electric 

vehicles. 

(3) Determine the CO2 emissions for the family certification level (FCL) from the 

emissions test results in paragraph (2) of eachthis section for engine familyies within the 

heavy-duty engine regulatory subcategories for each model year, in accordance with 40 
CFR part 1036, subpart C, and then calculate equivalent fuel consumption values for each 

family certification level. 

(i) Determine the CO2 family certification level in grams per bhp-hr. 

(ii) Calculate equivalent fuel consumption values, in gallons per 100 bhp-hr. 

(iii) Round each fuel consumption value to the nearest 0.1 gallon per 100 bhp-hr.

(2(i) If a manufacturer certifies an engine family for use both as a vocational engine 

and as a tractor engine, the manufacturer must split the family into two separate 

subfamilies. in accordance with 40 CFR part 1036.230. The manufacturer may assign the 

numbers and configurations of engines within the respective subfamilies at any time prior 

to the submission of the end-of-year report required by 40 CFR 1036.730 and § 535.8. 

The manufacturer must track into which type of vehicle each engine is installed, although 

EPA may allow the manufacturer to use statistical methods to determine this for a 

fraction of its engines. 

(3ii) The following engines are excluded from the engine families used to determined 

FCL values and the benefit for these engines is determined as an advanced technology 

credits under the ABT provisions provided in § 535.7(e): 

(iA) Engines certified as hybrid engines or power packs. 

(iiB) Engines certified as hybrid engines designed with PTO capability and that are 

sold with the engine coupled to a transmission. 

(iiiC) Engines with Rankine cycle waste heat recovery. 

(4) Manufacturers must submit the engine type fuel consumption values and the FCLs 

for engine families to NHTSA and EPA in accordance with § 535.8. After each model 

year ends, EPA will verify the manufacturer’s CO2 family certification levels through 

modeling and verify the equivalent fuel consumption values. EPA will prepare a final 

report with all the verified values and submit the report to the NHTSA after receiving the 

manufacturer’s end-of-the-year and final year reports as specified in § 535.8Calculate 

equivalent fuel consumption values for emissions FCLs and the CO2 levels for certified 

engines, in gallons per 100 bhp-hr and round each fuel consumption value to the nearest 

0.01 gallon per 100 bhp-hr. 

(i) Calculate equivalent fuel consumption FCL values for compression-ignition 

engines and alternative fuel compression-ignition engines. CO2 FCL value (grams per 

bhp-hr) / 10,180 grams per gallon of diesel fuel) x (102) = Fuel consumption FCL value 

(gallons per 100 bhp-hr).

(ii) Calculate equivalent fuel consumption FCL values for spark-ignition engines and 

alternative fuel spark-ignition engines. CO2 FCL value (grams per bhp-hr) / 8,877 grams 

per gallon of gasoline fuel) x (102) = Fuel consumption FCL value (gallons per 100 bhphr).

(iii) Manufacturers may carryover fuel consumption data from a previous model year 

if allowed to carry over emissions data for EPA in accordance with 40 CFR Part 

1036.235.

(iv) If a manufacturer uses an alternate test procedure under 40 CFR 1065.10 and 

subsequently the data is rejected by the EPA, NHTSA will also reject the data.

 

§ 535.7 Averaging, banking, and trading (ABT) Program. 
(a) Fuel consumption credits (FCC). At the end of each model year, manufacturers 

may earn credits for heavy-duty vehicles and engines exceeding the fuel consumption 

standards specifiedin § 535.5 or by using one or more of the flexibilities in this 

regulation.paragraph (a) to gain credits. Manufacturers may average, bank, and trade fuel 

consumption credits for purposes of complying with the fuel consumption standards. The 

following criteria and restrictions apply to averaging, banking and trading FCC (hereafter 

reference as described in this section.the NHTSA ABT program). 

(1) Averaging. Averaging is the exchange of FCC among a manufacturer’s engines 

or vehicle families or test groups within an averaging set. With the exception of FCC 

earned for advance technologies as further clarified below, a manufacturer may average 

FCC only within the same averaging set. The principle averaging sets are defined in 

535.4. 

 (2) Banking. Banking is the retention of surplus FCC by the manufacturer

generating the credits for use in future model years for averaging or trading. Banked 

FCC retain the designation from the averaging set and model year in which they were 

generated and expire after five model years. 

(3) Trading. Trading is a transaction that transfers FCC between manufacturers or 

other entities. A manufacturer may use traded FCC for averaging, banking, or further 

trading transactions. Traded FCC, other than advanced technology credits, may be used 

only within the averaging set in which they were generated.

(b) ABT provisions for heavy-duty pickup trucks and vans. (1) This regulatory 

category consists of one regulatory subcategory, heavy-duty pickup trucks and vans. 

This one regulatory subcategory makes up one averaging set. 

(2) Manufacturers that manufacture vehicles within this regulatory subcategory shall 

calculate credits at the end of each model year based upon the final average fleet fuel 

consumption standard and final average fleet fuel consumption performance value within 

this one regulatory subcategory as identified in paragraph (b)(8) of this section. If the 

manufacturer’s fleet includes conventional vehicles (gasoline, diesel and alternative fuel) 

and advanced technology vehicles (hybrids with regenerative braking, vehicles equipped 

with Rankine-cycle engines, electric and fuel cell vehicles) it should be divided into two 

separate fleets each with its own final average fleet fuel consumption standard and final 

average fleet fuel consumption performance value. Credits shall be calculated for each of 

the two fleets.

(3) Fuel consumption levels below the standard create a “credit surplus,” while fuel 

consumption levels above the standard create a “credit shortfall.” 

(4) Surplus credits, other than advanced technology credits, generated and calculated 

within this averaging set may only be used to offset a credit shortfall in this same 

averaging set .. 

(5) SurplusAdvanced technology credits can be used to offset a credit shortfall in this 

same averaging set or other averaging sets. However, a manufacturer must first apply 

advanced technology credits to any deficits in the same averaging set before applying 

them to other averaging sets.

(6) Surplus credits, other than advanced technology credits, may be traded among 

credit holders but must stay within the same averaging set. Advanced technology credits 

can be traded across averaging sets. 
 (6) Surplus credits, if not used to offset a credit shortfall may be banked by the 

manufacturer for use in future model years, or traded, given the restriction that the credits 

have an expiration date of five model years after the year in which the credits are earned. 

For example, credits earned in model year 2014 may be utilized through model year 

2019. 

(7) Credit shortfalls must be offset by an available credit surplus within three model 

years after the shortfall was incurred. If the shortfall cannot be offset, the manufacturer is 

liable for civil penalties as discussed in § 535.9.

(7) Surplus credits, if not used to offset a credit shortfall may be banked by the 

manufacturer for use in future model years, or traded, given the restriction that the credits 

have an expiration date of five model years after the year in which the credits are earned. 

For example, credits earned in model year 2014 may be utilized through model year 

2019. 

(8) Credit shortfalls must be offset by an available credit surplus within three model 

years after the shortfall was incurred. If the shortfall cannot be offset, the manufacturer is 

liable for civil penalties as discussed in § 535.9.

 (8(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)x(Volume)x(UL)x(102) 

 Where: 

Std = Fleet average fuel consumption standard (gal/100 mile). 

Act = Fleet average actual fuel consumption value (gal/100 mile). 

Volume = the total U.S. directed production of vehicles in the regulatory 

subcategory. 

UL = the useful life for the regulatory subcategory (120,000 miles). 

(9) In model year 2013,10) If a manufacturer voluntarily complies, it may 

calculategenerates credits forfrom its entire fleet, as specified in paragraph (b)(8) of this 

section, or it may choose to calculate onlyadvanced technology vehicles in accordance 

with 535.7(e)(1) a multiplier of 1.5 can be used. Advanced technology credits for its 

electriccan be used in other averaging sets different from the one they are generated 

within with the following restrictions. 

(i)The maximum amount of credits a manufacturer may bring into the service class 

group that contains the heavy-duty pickup and zero emissions vehicles van averaging set 

is 5.89 Mgallons (for advanced technology credits based upon compression ignition 

engines) or 6.76 Mgallons (for advanced technology credits based upon spark ignition 

engines) per model year as specified in 40 CFR part 1037.104: 

(ii) The limit specified in paragraph (b)(10)(i) of this section does not limit the 

amount of advanced technology credits that can be used across averaging sets within the 

same service class group. 

(11) Early credit provisions. If a manufacturer chooses to generate CO2 emission 

credits under EPA provisions of 1037.150(a), it may also voluntarily generate early 

credits under the NHTSA fuel consumption program. Fuel consumption credits may be 

generated for vehicles certified in model year 2013 to the model year 2014 standards in 

§ 535.5 (a). To do so a manufacturer must certify its entire U. S. directed production 

volume of vehicles in its fleet. The same production volume restrictions specified in 
§1037.150 (a)(2) relating to when test groups are certified apply to the NHTSA early 

credit provisions. Credits are calculated as specified in paragraph (e)(1b)(9) of this 

section relative to the fleet standard that would apply for model year 2014 using the 

model year 2013 production volumes. Surplus credits generated under this paragraph are 

available credits for banking or trading. Credit deficits for an averaging set prior to 

model year 2014 do not carry over to model year 2014. These credits may be used to 

show compliance with the standards of this part for 2014 and later model years. . Once a 

manufacturer opts into the NHTSA program they must stay in the program for all of the 

optional model years and remain standardized with the same implementation approach 

being followed to meet the EPA CO2 emission program. 

(c) ABT provisions for vocational trucksvehicles and tractors. (1) The two 

regulatory categories for vocational trucksvehicles and tractors consist of 12 regulatory 

subcategory as follows: 

(i) Vocational trucksvehicles with a GVWR up to and including 19,500 pounds 

(Light Heavy-Duty (LHD)); 

(ii) Vocational trucksvehicles with a GVWR above 19,500 pounds and no greater 

than 33,000 pounds (Medium Heavy-Duty (MHD)); 

(iii) Vocational trucksvehicles with a GVWR over 33,000 pounds (Heavy HeavyDuty (HHD)); 

(iv) Low roof day cab tractors with a GVWR above 26,000 pounds and no greater 

than 33,000 pounds; 

(v) Mid roof day cab tractors with a GVWR above 26,000 pounds and no greater 

than 33,000 pounds; 

(vi) High roof day cab tractors with a GVWR above 26,000 pounds and no greater 

than 33,000 pounds; 

 (vii) Low roof day cab tractors with a GVWR above 33,000 pounds; 

(viii) Mid roof day cab tractors with a GVWR above 33,000 pounds; 

(ix) High roof day cab tractors with a GVWR above 33,000 pounds; 

(x) Low roof sleeper cab tractors with a GVWR above 33,000 pounds; 

(xi) Mid roof sleeper cab tractors with a GVWR above 33,000 pounds; and 

(xii) High roof sleeper cab tractors with a GVWR above 33,000 pounds.

(2) The 12 regulatory subcategories consist of three averaging sets as follows:(xii) 

High roof sleeper cab tractors with a GVWR above 33,000 pounds.

(2) The 12 regulatory subcategories consist of three averaging sets as follows:(i) 

Vocational light-heavy vehicles at or below 19,500 pounds GVWR. 

(ii) Vocational and tractor medium-heavy vehicles above 19,500 pounds GVWR but 

at or below 33,000 pounds GVWR. 

(iii) Vocational and tractor heavy-heavy vehicles above 33,000 pounds GVWR. 

(3) Manufacturers that manufacture vehicles within either of these two vehicle 

categories, in one or more of the regulatory subcategories, shall calculate a total credit 

balance within each applicable averaging set at the end of each model year based upon 

final production volumes and the sum of the credit balances derived for each of the 

vehicle family groups within each averaging set.. .

(4) Each designated vehicle family group has a “family emissions limit” (FEL) 

which is compared to the associated regulatory subcategory standard. A FEL that falls 

below the regulatory subcategory standard creates “positive credits,” while fuel 
consumption level of a family group above the standard creates “negative creditsa “credit 

shortfall.” 

(5) Manufacturers shall sum all shortfalls and surplus credits for each vehicle family 

within each applicable averaging set to obtain the total credit balance for the model year 

before rounding. The sum of fuel consumptions credits must be rounded to the nearest 

gallon. 

(6) A surplus total credit balance Surplus credits, other than advanced technology 

credits, generated and calculated within anthis averaging set may only be used to offset a 

credit shortfallsshortfall in this same averaging set. 

(7) Advanced technology credits can be used to offset a credit shortfall in this same 

averaging set or other averaging sets. However, a manufacturer must first apply 

advanced technology credits to any deficits in the same averaging set. before applying 

them to other averaging sets.

 (7(8) Surplus credits, other than advanced technology credits, may be traded among 

credit holders but must stay within the same averaging set.

 (8) Surplus credits, if not used to offset a credit shortfall may be banked by the 

manufacturer for use in future model years, or Advanced technology credits can be 

traded, given the restriction that the credits have an expiration date of five model years 

after the year in which the credits are earned. across averaging sets. For example, credits 

earned in model year 2014 may be utilized through model year 2019. 

 (9) Surplus credits, if not used to offset a credit shortfall may be banked by the 

manufacturer for use in future model years, or traded, given the restriction that the credits 

have an expiration date of five model years after the year in which the credits are earned. 

For example, credits earned in model year 2014 may be utilized through model year 

2019. 

 (9) Credit shortfalls must be offset by available surplus credits within three 

model years after a shortfall has incurred. If the shortfall cannot be offset, the 

manufacturer is liable for civil penalties as discussed in § 535.9.

(10) Credit shortfalls must be offset by an available credit surplus within three model 

years after the shortfall was incurred. If the shortfall cannot be offset, the manufacturer is 

liable for civil penalties as discussed in § 535.9.

(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 

within an averaging set using the following equation: 

Vehicle Family FCC (gallons) = (Std –FEL)x(Payload)x(Volume)x(UL)x(103

) 

Where: 

Std = the standard for the respective vehicle family regulatory subcategory (gal/1000 

ton-mile). 

FEL = family emissions limit for the vehicle family (gal/1000 ton-mile). 

Payload = the prescribed payload in tons for each regulatory subcategory as shown in 

the following table: 

Regulatory subcategory Payload (Tons) 
LHD Vocational 

TrucksVehicles

2.85 

MHD Vocational 

TrucksVehicles

5.60 

HHD Vocational 

TrucksVehicles

7.5 

Class 7 Tractor 12.50 

Class 8 Tractor 19.00 

Volume = the number of U.S. directed production volume of vehicles in the

corresponding vehicle family. 

UL = the useful life for the regulatory subcategory (miles) as shown in the 

following table: 

Regulatory subcategory UL (miles) 

LHD Vocational 

TrucksVehicles

110,000 

MHD Vocational 

TrucksVehicles

185,000 

HHD Vocational 

TrucksVehicles

435,000 

Class 7 Tractor 185,000 

Class 8 Tractor 435,000 

(ii) Calculate the value of credits generated in a model year for each vehicle family 

for advanced technology vehicles within an averaging set using the equation above, the 

guidelines provided paragraph (e)(1)(i), and the 1.5 credit multiplier.

(iii) Calculate the total credits generated in a model year for each averaging set using 

the following equation: 

Total averaging set MY credits = ∑ Vehicle family credits within each averaging set 

(11) (12) Early credit provisions. (i) If a manufacturer chooses to generate 

CO2 emission credits under EPA provisions of 1037.150(a), it may also voluntarily 

generate early credits in MY 2013 by certifyingunder the NHTSA fuel consumption 

program. Fuel consumption credits may be generated for vehicles certified in model year 

2013 to the model year 2014 standards in § 535.5 (b) and (c). To do so a manufacturer 

must certify its entire fleet of vehicles in a specific subcategory to the respective MY

2014 standards.U. S. directed production volume of vehicles. The same production 

volume restrictions specified in §1037.150 (a)(1) relating to when test groups are 

certified apply to the NHTSA early credit provisions. Credits are calculated as specified 

in paragraph (c)(1011) of this section. If some vehicle families within a regulatory subcategory are certified after the start of the model year, credits can only be generated for 

production that occurs after all families are certified. relative to the standards that would 

apply for model year 2014. Surplus credits generated under this paragraph may be 

Formatted Table

Formatted Table
increased by a factor of 1.5 for determining total available credits for banking or trading. 

For example, if you have 1.010 gallons of surplus credits for model year 2013, you may 

bank 1.515 gallons of credits. Credit deficits for an averaging set prior to model year 

2014 do not carry over to model year 2014. These credits may be used to show 

compliance with the standards of this part for 2014 and later model years.. Once a 

manufacturer opts into the NHTSA program they must stay in the program for all of the 

optional model years and remain standardized with the same implementation approach 

being followed to meet the EPA CO2 emission program. 

(12) A tractor manufacturer may generate emission credits for the number of 

additional Smartway tractors (relative to its MY 2012 production). Calculate credits for 

each regulatory sub-category relative to the standard that would apply in model year 2014 

using the equations in paragraph (c)(10) above. Use a production volume equal to the

number of verified model year 2013 Smartway tractors minus the number of verified 

model year 2012 Smartway tractors. A manufacturer may bank credits equal to the 

surplus credits generated under this paragraph multiplied by 1.50. . Once a manufacturer 

opts into the NHTSA program they must stay in the program for all of the optional model 

years and remain standardized with the same implementation approach being followed to 

meet the EPA CO2 emission program. 

(ii) A tractor manufacturer may generate fuel consumption credits for the number of 

additional SmartWay designated tractors (relative to its MY 2012 production), provided 

that credits are not generated for those vehicles under paragraph (12)(i). Calculate credits 

for each regulatory sub-category relative to the standard that would apply in model year 

2014 using the equations in paragraph (c)(11) above. Use a production volume equal to 

the number of verified model year 2013 SmartWay tractors minus the number of verified 

model year 2012 SmartWay tractors. A manufacturer may bank credits equal to the 

surplus credits generated under this paragraph multiplied by 1.50. A manufacturer’s 

2012 and 2013 model years must be equivalent in length. Once a manufacturer opts into 

the NHTSA program they must stay in the program for all of the optional model years 

and remain standardized with the same implementation approach being followed to meet 

the EPA CO2 emission program. 

(13) Advanced technology credits. (i) If a manufacturer generates credits from 

vehicles certified for advanced technology in accordance with 535.7(e)(1) a multiplier of 

1.5 can be used, but this multiplier cannot be used on the same credits the early credit 

multiplier is used. Advanced technology credits can be used in other averaging sets 

different from the one they are generated within with the following restrictions. 

(ii) The maximum amount of credits a manufacturer may bring into a service class 

group that contains the vocational vehicle and tractor averaging sets is 5.89 Mgallons (for 

advanced technology credits based upon compression ignition engines) or 6.76 Mgallons 

(for advanced technology credits based upon spark ignition engines) per model year as 

specified in 40 CFR part 1037.740: 

(iii) The limit specified in paragraph (c)(13)(i) of this section does not limit the 

amount of advanced technology credits that can be used across averaging sets within the 

same service class group. 

 (d) ABT provisions for heavy-duty engines. (1) Heavy-duty engines consist of six 

regulatory subcategories as follows: 

(i) Spark-ignition engines. 
(ii) Light heavy-duty compression-ignition engines. 

(iii) Medium heavy-duty vocational compression-ignition engines. 

(iv) Medium heavy-duty tractor compression-ignition engines 

(ivv) Heavy heavy-duty vocational compression-ignition engines. 

(ivvi) Heavy heavy-duty tractor compression-ignition engines. 

(2) The six regulatory subcategories consist of four averaging sets as follows: 

(i) Compression-ignition light heavy-duty diesel engines for Class 2b to 5 trucks 

with a GVWR above 8,500 pounds but at or below 19,500 pounds. 

(ii) Compression-ignition medium heavy-duty diesel engines for Class 6 and 7 trucks 

with a GVWR above 19,500 but at or below 33,000 pounds. 

(iii) Compression-ignition heavy heavy-duty diesel engines for Class 8 trucks with a 

GVWR above 33,000 pounds. 

(iv) Spark ignition engines in Class 2b to 8 trucks with a GVWR above 8,500 

pounds. 

 (3) Manufacturers that manufacture engines within one or more of the regulatory 

subcategories, shall calculate a total credit balance within each applicable averaging set at 

the end of each model year based upon final production volumes and the sum of the 

credit balances derived for each of the engine families within each averaging set. 

 (4) Each designated engine family has a “family certification level” (FCL) which is 

compared to the associated regulatory subcategory standard. A FCL that falls below the 

regulatory subcategory standard creates “positive credits,” while fuel consumption level 

of a family group above the standard creates “negative creditsa “credit shortfall.” 

 (5) Manufacturers shall sum all surplus and shortfall credits for each engine family 

within the applicable averaging set to obtain the total credit balance for the model year 

before rounding. Round the sum of fuel consumptions credits to the nearest gallon. 

 (6) A surplus total credit balanceSurplus credits, other than advanced technology 

credits, generated and calculated within anthis averaging set may only be used to offset a 

credit shortfalls in this same averaging set. 

(7) Advanced technology credits can be used to offset a credit shortfall in this same 

averaging set or other averaging sets. However, a manufacturer must first apply 

advanced technology credits to any deficits in the same averaging set before applying 

them to other averaging sets.

(8) Surplus credits, other than advanced technology credits, may be traded among 

credit holders but must stay within the same averaging set. Advanced technology credits 

can be traded across averaging sets. 

 (8(9) Surplus credits, if not used to offset a credit shortfall may be banked by the 

manufacturer for use in future model years, or traded, given the restriction that the credits 

have an expiration date of five model years after the year in which the credits are earned. 

For example, credits earned in model year 2014 may be utilized through model year 

2019. 

 (910) Credit shortfalls must be offset by available surplus credits within three model 

years after shortfall was incurred. If the shortfall cannot be offset, the manufacturer is 

liable for civil penalties as discussed in § 535.9. 

 (1011) 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)x(CF)x(Volume)x(UL)x(102

) 

Where: 

Std = the standard for the respective engine regulatory subcategory (gal/100 bhp-hr). 

FCL = family certification level for the engine family (gal/100 bhp-hr). 

CF= a transient cycle conversion factor in bhp-hr/mile which is the integrated total 

cycle brake horsepower-hour divided by the equivalent mileage of the applicable test 

cycle. For spark-ignition heavy-duty engines, the equivalent mileage is 6.3 miles. For 

compression-ignition heavy-duty engines, the equivalent mileage is 6.5 miles. 

Volume = the number of engines in the corresponding engine family. 

UL = the useful life of the given engine family (miles) as shown in the following 

table: 

 Regulatory Subcategory UL (miles) 

Class 2b-5 Vocational TrucksVehicles, 

Spark Ignited (SI), and Light Heavy-Duty 

Diesel Engines 

110,000 

Class 6-7 Vocational TrucksVehicles

and Medium Heavy-Duty Diesel Engines 

185,000 

Class 8 Vocational TrucksVehicles and 

Heavy Heavy-Duty Diesel Engines 

435,000 

 Regulatory Subcategory UL (miles) 

Class 7 Tractors and Medium HeavyDuty Diesel Engines 185,000 

Class 8 Tractors and Heavy Heavy-Duty 

Diesel Engines 

435,000 

(ii) Calculate the total credits generated in a model year for each averaging set using 

the following equation: 

Total averaging set MY credits = ∑Engine family credits within each averaging set 

(11) (12) Alternate standard provisions for compression ignition engines. (i) 

The provisions of this section apply to manufacturers utilizing the voluntary alternate 

standard provisions specified in § 535.5(d)(4). 

(ii) Manufacturers may not certify engines to the alternate standards if they are part 

of an averaging set in which they carry a balance of banked credits. For purposes of this 

section, manufacturers are deemed to carry credits in an averaging set if they carry credits 

from advance technology that are allowed to be used in that averaging set.

(iii) Manufacturers may not bank fuel consumption credits for any engine family in 

the same averaging set and model year in which it certifies engines to the alternate 

standards. This means a manufacturer may not bank advanced technology credits in a 

model year it certifies any engines to the alternate standards. 
(iv) Note that the provisions of §535.7(d)(10) apply with respect to credit deficits 

generated while utilizing alternate standards.

(13) Alternative phase-in standard provisions for compression ignition engines. 

Where a manufacturer has chosen to comply with the EPA alternative phase-in standard 

provisions in 1036.150(e), and has optionally decided to follow the same path under the 

NHTSA fuel consumption program, it must certify all of its model year 2013 

compression-ignition engines within a given averaging set to the applicable alternative 

standards in 535.5(d)(5). Engines certified to these standards are not eligible for early 

credits under paragraph (14) of this section. Credits are calculated using the same 

equation provided in paragraph (11) of this section.

(14) Early credit provisions. If a manufacturer chooses to generate CO2 emission 

credits under EPA provisions of 1036.150, it may also voluntarily generate early credits 

in MY 2013 by certifyingunder the NHTSA fuel consumption program. Fuel 

consumption credits may be generated for engines certified in model year 2013 (2015 for 

spark-ignition engines) to the standards in § 535.5 (d). To do so a manufacturer must 

certify its entire fleet of engines in a specific subcategory to the respective MY 2014 

standards. Credits are calculated U. S. directed production volume of engines except 

as specified in 40 CFR part 1036.150(a)(2). Credits are calculated as specified in 

paragraph (d)(1011) of this section. If some engine families within a regulatory subcategory are certified after relative to the start of the standards that would apply for 

model year, credits can only be generated for production that occurs after all 

families are certified. 2014 (2016 for spark-ignition engines). Surplus credits 

generated under this paragraph may be increased by a factor of 1.5 for determining total 

available credits for banking or trading. For example, if you have 1.010 gallons of 

surplus credits for model year 2013, you may bank 1.515 gallons of credits. Credit 

deficits for an averaging set prior to model year 2014 (2016 for spark-ignition engines) 

do not carry over to model year 2014. These credits may be used to show compliance 

with the standards of this part for 2014 and later model years. (2016 for sparkignition engines). These credits may be used to show compliance with the standards of 

this part for 2014 and later model years. Once a manufacturer opts into the NHTSA 

program they must stay in the program for all of the optional model years and remain 

standardized with the same implementation approach being followed to meet the EPA 

CO2 emission program.

(15) Advanced technology credits. (i) If a manufacturer generates credits from 

engines certified for advanced technology in accordance with 535.7(e)(1) a multiplier of 

1.5 can be used, but this multiplier cannot be used on the same credits the early credit 

multiplier is used. Advanced technology credits can be used in other averaging sets 

different from the one they are generated within with the following restrictions. 

(ii) The maximum amount of credits a manufacturer may bring into a service class 

group that contains the heavy-duty engine averaging sets is 5.89 Mgallons (for advanced 

technology credits based upon compression ignition engines) or 6.76 Mgallons (for 

advanced technology credits based upon spark ignition engines) per model year as

specified in 40 CFR part 1036.740: 

(iii) The limit specified in paragraph (d)(15)(ii) of this section does not limit the 

amount of advanced technology credits that can be used across averaging sets within the 

same service class group. 
(e) Additional credit provisions. (1) Advanced technology credits. Manufacturers of 

heavy-duty pickup trucks and vans, vocational trucks andvehicles, tractors and 

associated engines showing improvements in CO2 emissions and fuel consumption using 

hybrid vehicles with regenerative braking, vehicles equipped with Rankine-cycle engines, 

electric vehicles and fuel cell vehicles are eligible for advanced technology credits that. 

Advanced technology credits may be increased by a 1.5 multiplier and applied to any 

heavy-duty vehicle or engine subcategory consistent with sound engineering judgment as 

follows:.

(i) Heavy-duty vocational trucks and truck tractorsvehicles. (A) For advanced 

technology system (hybrid vehicles with regenerative braking (or the equivalent) and 

energy storage systems and for hybrids that incorporate power take-off (PTO) systems,, 

vehicles equipped with Rankine-cycle engines and fuel cell vehicles), calculate the 

advanced technology credits as follows: 

(1) Measure the effectiveness of the hybridadvanced system by simulating the chassis test 

procedure applicable for each type of hybrid vehicle under 40 CFR part 1037. 

(2) The effectiveness of the hybrid system is measured using chassis testing against a 

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

system in accordance with 40 CFR part 1037.615. 

(2) For purposes of this paragraph (e), a conventional vehicle is considered to be 

equivalent if it has the same footprint, intended vehicle service class, aerodynamic drag, 

and other relevant factors not directly related to the hybridadvanced system powertrain. 

If there is no equivalent vehicle, the manufacturer may create and test a prototype 

equivalent vehicle. The conventional vehicle is considered Vehicle A, and the 

hybridadvanced technology vehicle is considered Vehicle B. EPA may specify an 

alternate test if the hybrid vehicle includes a power take-off system.

(3) The benefit associated with the hybridadvanced system for fuel consumption is 

determined from the weighted fuel consumption results from the chassis tests of each 

vehicle using the following equation: 

Benefit (gallon/1000 ton mile) = Improvement Factor x GEM Fuel Consumption 

Result_B 

Where: 

Improvement Factor = (Fuel Consumption_A – Fuel Consumption_B)/(Fuel 

Consumption_A) 

Fuel Consumption Rates A and B are the gallons per 1000 ton-mile of the 

conventional and hybridadvanced vehicles, respectively as measured under the test 

procedures specified by EPA. 

GEM Fuel Consumption Result B is the estimated gallons per 1000 ton-mile rate 

resulting from emission modeling the emissions of the hybridadvanced vehicle as 

specified in 40 CFR 1037.520 and § 535.6(b) and (c). 

(4) Calculate the benefit in credits using the equation in paragraph 535.7(d)(10c)(11) 

of this section and replacing the term (Std-FEL) with the benefit. 

(B) For Rankine Cycle engines, determine the emission performance benefit 

according to 40 CFR 1036.615 and convert to an equivalent fuel consumption benefit 

value. Calculate fuel consumption credits in gallons utilizing the credit equation in 

paragraph 535.7(d)(10) of this section and replacing the term (Std-FCL) with the fuel 
consumption benefit value. electric vehicles calculate the fuel consumption credits using 

an FEL of 0 g/1000ton-mile. 

(C) For electric and fuel cell vehicles, determine the emission performance benefit 

according to 40 CFR 1037.610 and convert to an equivalent fuel consumption benefit 

value. Calculate fuel consumption credits in gallons utilizing the credit equation in 

paragraph 535.7(d)(10) of this section and replacing the term (Std-FEL) with the fuel 

consumption benefit value. 

(ii) Heavy-duty pickup trucks and vans. (A) For model year 2013, manufacturers may 

generate advanced technology credits for electric and zero emissions vehicles. Advanced 

technology credits for electric and zero emissions vehicles may be earned voluntarily as 

an alternative to generating credits for the manufacturer’s entire fleet. Advanced 

technology credits for electric and zero emissions vehicles are not limited for use within 

the heavy-duty pickup truck and van regulatory category. Advanced technology credits 

generated for electric and zero emission vehicles in model year 2013 are treated as 

though they were generated in model year 2014 for purposes of credit life. 

(B) In model years 2014 and later, a manufacturer may choose to calculate credits for 

its entire fleet as specified in paragraph 535.7 (b)(8) of this section or may choose to 

exclude its electric vehicles and zero emissions vehicles from the fleet and calculate the 

credits for these vehicles separately as advanced technology credits. In this case, the 

manufacturer may gain credits for its fleet without its electric and zero emissions vehicles 

and gain the advanced technology credits for these vehicles. Advanced technology 

credits for electric and zero emissions vehicles are not limited for use within the heavyduty pickup truck and van regulatory category.(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 engine braking) and for engines that include Rankine-cycle (or 

other bottoming cycle) exhaust energy recovery systems. 

(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 engine test procedures of 40 CFR 

part 1065 or using the post-transmission test procedures.

(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. 

(3) Test engines that include Rankine-cycle exhaust energy recovery systems 

according to the test procedures specified in 40 CFR part 1036 subpart F of this part 

unless EPA approves the manufacturer’s alternate procedures.

 (B) Calculate credits as specified in § 535.7(c) of this part. Credits generated from 

engines and powertrains certified under this section may be used in other averaging sets 

as described in 40 CFR part 1036.740(d). 

(2) Innovative technology credits. EPA This provision allows engine and vehicle 

manufacturers to generate CO2 emission credits consistent with the provisions of 40 CFR 

86.1866-12(dpart 1036.610 (for engines), 40 CFR part 1037.104(d)(13) (for heavy-duty 

pickup trucks and vans) and 40 CFR part 1037.610 (for vocational vehicles and tractors) 

for introducing innovative technology in heavy-duty engines and vehicles for reducing 
greenhouse gas emissions. and fuel consumption. Upon identification and approval from 

EPA of a manufacturer seeking to obtain innovative technology credits in a given model 

year, NHTSA may adopt the samean equivalent amount of fuel consumption credits into 

its program. Such credits must remain within the same regulatory subcategory in which 

the credits were generated. NHTSA will adopt these fuel consumption credits depending 

upon whether: 

(i) The technology has a direct impact upon reducing fuel consumption performance; 

(ii) The manufacturer has provided sufficient information to make sound engineering 

judgments on the impact of the technology in reducing fuel consumption performance; 

and 

(iii) Credits will be accepted on a one-for-one basis expressed in terms of gallons. 

§ 535.8 Reporting requirements. 

(a) General Requirements. (1) Required reports. For each model year, manufacturers 

producing heavy-duty trucks and engines as identified in § 535.3 must submit through the 

EPA VERIFY compliance database system, applications for certificates of conformity, 

end-of-the-year and final reports, amendments to applications for certification, and any 

applicable compliance letters and requests . Manufacturers producing heavy-duty pickup 

trucks and vans must submit a pre-model report for each model year through the EPA 

VERIFY database. NHTSA will access the manufacturer’s information through the EPA 

VERIFY database to ensure compliance with its standards.

(2) Report deadlines. Reports

(a) General Requirements. Manufacturers producing heavy-duty vehicles and engines 

applicable to fuel consumption standards in § 535.5, for each given model year, must 

submit the required information as specified in paragraphs (b) through (h) of this section. 

(1) The information required by this part for each model year must be submitted by 

the deadlines specified in this section and must be based upon all the information and 

data available to the manufacturer 30 days before submitting information into the EPA 

VERIFY database.. 

(i) Pre-model year report for heavy-duty pickup truck and van. For model years 2013 and 

later, manufacturers complying with NHTSA standards must submit a pre-model year 

report in accordance with § 1036.xxx and § 1037.xxx [EPA please provide] through the 

EPA VERIFY database including both GHG emissions and fuel consumption information 

for each given model year. The report can be sent as early as the date of the 

manufacturer’s annual certification preview meeting, or as late as the date the 

manufacturer submits its first application for a certificate of conformity for the given 

model year. For example, a manufacturer could arrange a precertification compliance 

meeting with EPA and NHTSA on December 31, 2012, and at that time submit through 

the EPA VERIFY database its model year 2014 pre-model year report containing both 

GHG emission and fuel consumption information. 

(ii) Applications for certificate of conformity for heavy-duty trucks and engines. For 

model years 2013 and later, manufacturers complying with NHTSA standards must 

submit its applications for certificates of conformity in accordance with § 1036.201 and 

§ 1037.201 through the EPA VERIFY database including both GHG emissions and fuel 

consumption information for each given model year. 
(iii) End-of-the-year-report for all heavy-duty trucks and engines. For model year 2013 

and later, manufacturers complying with NHTSA’s standards must submit an end-of-theyear report in accordance with § 1036.730 and § 1037.730 through the EPA VERIFY 

database including both GHG emissions and fuel consumption information for each given 

model year. This report must be submitted within 90 days after the end of the given 

model year and no later than April 1 of the next calendar year. For example, the end-ofthe-year report for model year 2014 must be submitted no later than April 1, 2015.

(A) Upon notification from EPA, NHTSA may waive the requirement to send the endof-the year report, conditioned upon the manufacturer contacting EPA by letter to certify 

that the final report will be sent on time. NHTSA will not waive this requirement for a 

manufacturer that has a deficit for a given model year or an outstanding deficit from a 

prior model year.

(B) If a manufacturer expects differences in the information reported between the endof-the-year report and the final year report, it must provide the most up-to-date 

projections in the end-of-the-year report and indentify the information as preliminary. 

(C) If the manufacturer cannot provide any of the required fuel consumption 

information, it must state the specific reason for the insufficiency and identify the 

additional testing needed or explain what analytical methods are believed by the 

manufacturer will be necessary to eliminate the insufficiency and certify that the results 

will be available for the final report. 

(iv) Final report for all heavy-duty trucks and engines. For model year 2013 and later, 

manufacturers complying with NHTSA’s standards must submit a final report in 

accordance with § 1036.730 and § 1037.730 through the EPA VERIFY database 

including both GHG emissions and fuel consumption information for each given model

year. This report must be submitted within 270 days after the given model year and no 

later than October 1 of the next calendar year. For example, the final year report for 

model year 2014 must be submitted no later than October 1, 2015.

(v) Amendments to applications for certification. At any time, a manufacturer 

modifying an application for certification in accordance with § 1036.225 and 

§ 1037.225 must submit any GHG emissions changes with equivalent fuel consumption 

information, if applicable. 

(b) General submission provisions. (1) For model years 2013 and later, a manufacturer 

must follow the instructions on the EPA VERIFY database for submitting information 

electronically. 

(2)(2) Manufacturers must submit information electronically through the EPA 

database system as the single point of entry for all information required for this national 

program and both agencies will have access to the information. The format for the 

required information is specified by EPA. 

(3) If by model year 2012, the agencies are not prepared to receive information 

through the EPA VERIFY database system, manufacturers are expectedrequired to 

submit written reportsinformation to the agencies in a EPA using an approved 

information format that. A manufacturer can be downloaded from EPA.use a different 

format, if it sends EPA a written request with justification for a waiver.

(3) Electronic submissions through the EPA VERIFY database must include all the 

required information specified in paragraphs (b) through (e) of this section to be 

accepted.
(vi) Additional Reporting Provisions. Throughout the model year, manufacturers of 

heavy-duty trucks and engines, except for those(b) Pre-model year reports. 

Manufacturers producing heavy-duty pickup trucks and vans, will be required to submit 

various submissions to must submit reports in advance of the model year providing early 

estimates demonstrating how their fleet(s) would comply with GHG emissions and fuel 

consumption standards. Note, the agencies to comply with various aspects of the rule. 

The criteria for submission, approval and due dates are specified in section(c) and section 

xxxx of this part. For understand that early model year reports contain estimates that may 

change over the course of a model year and that compliance information manufactures 

submit prior to the beginning of a new model year may not represent the final compliance 

outcome. The agencies view the necessity for requiring early model reports as a 

manufacturer’s good faith projection for demonstrating compliance with emission and 

fuel consumption standards. 

 (1) Report Deadlines. For model years 2013 and later, manufacturer of heavy-duty 

pickup trucks and vans, the same submissions are include in the complying with 

voluntary and mandatory standards must submit a pre-model year report for the given 

model year as early as the date of the manufacturer’s annual certification preview 

meeting with EPA and NHTSA, or prior to submitting its first application for a certificate 

of conformity to EPA in accordance with 40 CFR part 1037.104(d). For example, a 

manufacturer choosing to comply in model year 2014 could submit its pre-model year 

report during its precertification meeting which could occur before January 2, 2013, or 

could provide its pre-model year report in section (c).any time prior to submitting its first 

application for certification for the given model year. 

(c) Pre-model year report.(2) Contents. Each pre-model year report for heavy-duty 

pickup trucks and vans must comply with the provisions in § 1036.xxx and § 1037.xxx 

[EPA please provide] and paragraph (c). NHTSA reserves the right to ask a 

manufacturer to provide additional information if necessary to verify the fuel 

consumption requirements of this regulation. 

(1) Vehicle and Fleet Information. Each reportbe submitted electronically through 

the EPA VERIFY database system must includeincluding the following information: for 

each model year. 

(i) A list of each unique vehicle configuration includedsubconfiguration in the 

manufacturer’s fleet describing the make and model designations, attribute based-values 

(i.e., GVWR, GCWR, Curb Weight and drive configurations) and standards.;

(ii) The emission and fuel consumption fleet average standard derived from the 

unique vehicle configurations; 

(iii) The estimated vehicle configuration, test group and fleet production volumes; 

(iv) The expected emissions and fuel consumption test group results and fleet 

average performance; 

(2) Required Statements and Plans. Each report submitted electronically through the 

EPA VERIFY database system must include the following information: 

(i) A v) If complying with MY 2013 fuel consumption standards, a statement must be 

provided declaring whether the manufacturer will use fixed or increasing standards; 

acknowledging that once selected, the decision cannot be reversed and the manufacturer 

must continuethat the manufacturer is voluntarily choosing to comply early with the same 

alternative for subsequent model years;
(ii) A statement declaring whether the manufacturer chooses to comply early in MY 

2013 for EPA and NHTSA programs. The manufacturers must also acknowledge that 

once selected, the decision cannot be reversed and the manufacturer will continue to 

comply with the fuel consumption standards for subsequent model years for all the 

vehicles it manufacturers in each regulatory category for a given model year; 

(iii) vi) If complying with MYs 2014, 2015 or 2016 fuel consumption standards, a 

statement must be provided declaring whether the manufacturer chooseswill use fixed or 

increasing standards in accordance with Part 535.5(a). The manufacturer must also 

acknowledge that once selected, the decision cannot be reversed and the manufacturer 

must continue to comply with the same alternative for subsequent model years for all the

vehicles it manufacturers in each regulatory category for a given model year;

(vii) If complying with MYs 2014 or 2015 fuel consumption standards, a statement 

must be provided declaring that the manufacturer is voluntarily choosing to comply with 

NHTSA’s voluntary fuel consumption standards for model years 2014 through 2015.in 

accordance with Part 535.5(a)(4). The manufacturers must also acknowledge that once 

selected, the decision cannot be reversed and the manufacturer will continue to comply 

with the fuel consumption standards for subsequent model years for all the vehicles it 

manufacturers in each regulatory category for a given model year; 

(ivviii) The list of Class 2b-3 incomplete (cab-complete or chassis complete vehicles) 

and the method used to certify these vehicles as complete pickups and vans identifying 

the most similar complete sister- or other complete vehicles used to derive the target 

standards and performance test results;

(ix) The list of Class 4 and 5 incomplete and complete vehicles and the method use 

to certify, as vocational these vehicles and engines, or as complete pickups and vans 

identifying the most similar complete or sister vehicles used to derive the target standards 

and performance test results; 

(vi) x) List of loose engines included in the heavy-duty pickup and van category and

the list of vehicles used to derive target standards and performance test results; 

(xi) Copy of any notices a vehicle manufacturer is designating to include in the low 

volume exclusion; andsends to the engine manufacturer to notify the engine 

manufacturers that their engines are subject to emissions and fuel consumption standards 

and that it intends to use their engines in excluded vehicles; 

(viixii) A credit plan identifying the manufacturers estimated credit balances, planned 

credit flexibilities (i.e., credit balances, planned credit trading, innovative, advanced and 

early credits and etc.) and if needed a credit deficit plan demonstrating how it plans to 

resolve any credit deficits that might occur for a model year within a period of up to three 

model years after that deficit has occurred. (A) The final fuel consumption standards;

(d) Applications for Certificates of Conformity. When submitting applications for 

certificates of conformity in accordance with § 1036.205 and § 1037.205, manufacturers 

must submit equivalent fuel consumption information where applicable. NHTSA 

reserves the right to ask a manufacturer to provide additional information if necessary to 

verify the fuel consumption requirements of this regulation. 

(e) End-of-the-year and final reports. When submitting end-of-the-year and final reports 

in accordance with § 1036.730 and § 1037.730 and paragraph (e), manufacturers must 

submit equivalent fuel consumption information where applicable. NHTSA reserves the 
right to ask a manufacturer to provide additional information if necessary to verify the 

fuel consumption requirements of this regulation. 

(1) Heavy-duty Pickup Trucks and Vans. (i) Vehicle Information. Each report 

submitted electronically for heavy-duty pickups trucks and vans through the EPA 

VERIFY database system must include the following information: 

(A) A finalized list of each unique vehicle configuration included in the manufacturers 

fleet describing the designations, attribute based-values (GVWR, GCWR, Curb Weight 

and drive configurations) and standards.

(B) The final emission and fuel consumption fleet average standard derived from the 

unique vehicle configurations;

(C) The final vehicle configuration, test group and fleet production volumes;

(D) The final emissions and fuel consumption test group results and fleet average 

performance; 

(ii) Required Lists and Plans. Each report submitted electronically through the EPA 

VERIFY database system must include the following information: 

(A) The final list of cab-complete vehicles and the method use to certify, as vocational 

vehicles and engine, or as complete pickups and vans identifying the most similar 

complete vehicles used to derive the target standards and performance test results;

(B) The final list of vehicles a manufacturer is designating to include in the low volume 

exclusion; 

(C) A final credit plan identifying the manufacturers estimated credit balances, 

planned credit flexibilities (i.e., credit balances, planned credit trading, innovative, 

advanced and early credits and etc.) and if needed a credit deficit plan demonstrating how 

it plans to resolve any credit deficits that might occur for a model year within a period of 

up to three model years after that deficit has occurred; and

(Dxiii) The supplemental information specified in paragraph (h) of this part. Note, 

NHTSA may also ask a manufacturer to provide additional information if necessary to 

verify compliance with the fuel consumption requirements of this regulation. 

(c) Applications for certificate of conformity. Manufacturers producing vocational 

vehicles, tractors and heavy-duty engines are required to submit applications for 

certificates of conformity to EPA in accordance with 40 CFR part 1036.205 and 40 CFR 

part 1037.205 in advance of introducing vehicles for commercial sale. Applications

contain early model year information demonstrating how manufacturers plan to comply 

with GHG emissions. For model years 2013 and later, manufacturers of vocational 

vehicles, tractors and engine complying with NHTSA’s voluntary and mandatory 

standards must submit applications for certificates of conformity in accordance through 

the EPA database including both GHG emissions and fuel consumption information for 

each given model year. 

(1) Submission Deadlines. Applications are primarily submitted in advance of the 

given model year to EPA but cannot be submitted any later than December 31st of the 

given model year. 

(2) Contents. Each application for certificates of conformity submitted to EPA must 

include the following equivalent fuel consumption.

(i) Equivalent fuel consumption values for emissions CO2 FCLs values used to 

certify each engine family in accordance with 1036.205(e). This provision applies only 

to manufacturers producing heavy-duty engines. 
(ii) Equivalent fuel consumption values for emission CO2 data engines used to 

comply with emission standards in § 1036.108. This provision applies only to 

manufacturers producing heavy-duty engines. 

(iii) Equivalent fuel consumption values for emissions CO2 FELs values used to 

certify each vehicle families or subfamilies in accordance with 1037.205(k). This 

provision applies only to manufacturers producing vocational vehicles and tractors. 

(iv) Report modeling results for ten configurations in terms of CO2 emissions and 

equivalent fuel consumption results in accordance with 1037.205(o). Include modeling 

inputs and detailed descriptions of how they were derived. This provision applies only to 

manufacturers producing vocational vehicles and tractors. 

(3) Additional supplemental information. Manufacturers are required to submit 

additional information as specified in paragraph (h) of this part for the NHTSA program 

before or at the same time it submits its first application for a certificate of conformity to 

EPA. 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.

(d) End-of-the-Year-Report. Both manufacturers participating and not participating in 

the ABT program are required to submit year end reports; end-of-the-year (EOY) reports 

in accordance with 40 CFR part 1036.730 and 40 CFR part 1037.730. The EOY reports 

are used to review a manufacturer’s preliminary final estimates 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. 

(1) Report Deadlines. For model year 2013 and later, heavy-duty vehicle and engine 

manufacturers complying with NHTSA voluntary and mandatory standards must submit 

EOY reports through the EPA database including both GHG emissions and fuel 

consumption information within 90 days after the end of the given model year and no 

later than April 1 of the next calendar year. For example, the EOY report for model year 

2014 must be submitted no later than April 1, 2015.

(i) If a manufacturer expects differences in the information reported between the 

EOY and the final year report specified in 40 CFR part 1036.730 and 40 CFR part 

1037.730, it must provide the most up-to-date fuel consumption projections in its EOY 

report and indentify the information as preliminary. 

(ii) If the manufacturer cannot provide any of the required fuel consumption 

information, it must state the specific reason for the insufficiency and identify the 

additional testing needed or explain what analytical methods are believed by the 

manufacturer will be necessary to eliminate the insufficiency and certify that the results 

will be available for the final report. 

(2) Contents. Each EOY report must be submitted including the following fuel 

consumption information for each model year. 

(i) Engine and vehicle family designations and averaging sets.

(ii) Engine and vehicle regulatory subcategory and fuel consumption standards 

including any alternative standards used.

(iii) Engine and vehicle family FCLs and FELs in terms of fuel consumption.
(iv) Production volumes for engines and vehicles.

(v) A credit plan (for manufacturers participating in the ABT program) identifying 

the manufacturers actual fuel consumption credit balances, credit flexibilities, credit 

trades and a credit deficit plan if needed demonstrating how it plans to resolve any credit 

deficits that might occur for a model year within a period of up to three model years after 

that deficit has occurred 

(vi) A plan describing the vocational vehicles and vocational tractors that were 

exempted such as forheavy-duty off-road or small business purposes; andvehicles.

(Evii) A final plan describing any advanced 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. 

(2) Heavy-Duty Tractors, Vocational Vehicles and Engines. (i) Vehicle Information. 

Each report submitted electronically for heavy-duty tractors, vocational vehicles and 

engines through the EPA VERIFY database system must include the following 

information

(A) Vehicle or engine (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 heavyduty 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. 

(xii) Under limited conditions, NHTSA may also ask a manufacturer to provide 

additional information directly to the Administrator if necessary to verify the fuel 

consumption requirements of this regulation.

(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 part 

1036.730 and 40 CFR part 1037.730. 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. 

(1) Report Deadlines. For model year 2013 and later, heavy-duty vehicle and engine 

manufacturers complying with NHTSA voluntary and mandatory standards must submit 

final reports through the EPA database including both GHG emissions and fuel

consumption information within 270 days after the end of the given model year and no 

later than October 1 of the next calendar year. For example, the final reports for model 

year 2014 must be submitted no later than October 1, 2015. 
(2) Contents. Each final report must be submitted including the following fuel 

consumption information for each model year. 

(i) Final engine and vehicle family designations and averaging sets. 

(B) Vehicle orii) Final engine emissions and vehicle fuel consumption standards 

including any alternative standards used.

(C) Vehicle or iii) Final engine and vehicle family FCLs and FELs in terms of fuel 

consumption. 

(Div) Final production volumes

(E) Certified test cycles

(F) Useful life values for vehicle or engine familiesengines and vehicles.

(ii) Required Plans. Each report submitted electronically through the EPA VERIFY 

database system must include the following information: 

((v) A) A final credit plan identifying the manufacturers actual fuel consumption

credit balances, credit flexibilities, credit trades and a credit deficit plan if needed 

demonstrating how it plans to resolve any credit deficits that might occur for a model 

year within a period of up to three model years after that deficit has occurred 

(B)vi) A final plan describing the actualvocational vehicles and vocational tractors 

that were exempted such as forheavy-duty off-road or small business purposesvehicles.

(Cvii) A final plan describing the actualany advanced 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 heavyduty 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. 

(xii) Under limited conditions, NHTSA may also ask a manufacturer to provide 

additional information directly to the Administrator if necessary to verify the fuel 

consumption requirements of this regulation.

(f) Amendments to applications for certification. At any time, a manufacturer 

modifies an application for certification in accordance with § 1036.225 and § 1037.225, 

it must submit GHG emissions changes with equivalent fuel consumption values for the 

information required in paragraphs (b) through (e) and (h) of this part. 

(g) Confidential Information. Manufacturers must submit a request for 

confidentiality with each electronic specifying any part of the for information or data in a 

report that it believes should be withheld from public disclosure as trade secret or other 

confidential business information. Information submitted to EPA should follow EPA 

guidelines for treatment of confidentiality. Confidential information submitted to 

NHTSA shall be treated according to paragraph (g)(1) of this section.
(1) For any information or data requested by the manufacturer to be withheld under 5 

U.S.C. 552(b)(4) and 15 U.S.C. 2005(d)(1), the manufacturer shall provide evidence in 

its request for confidentiality to justify that:

(i) The item is within the scope of 5 U.S.C. 552(b)(4) and 15 U.S.C. 2005(d)(1);

(ii) The disclosure of such as item would result in significant competitive damage;

(iii) The period during which the item must be withheld to avoid that damage; and

(iv) How earlier disclosure would result in that damage.

(h) Additional reporting provisions for Tractors and Vocational Vehicles and 

EnginesRequired Information. The following additional information is required to be 

submitted through the EPA VERIFY database. NHTSA reserves the right to ask a 

manufacturer to provide additional information if necessary to verify the fuel 

consumption requirements of this regulation. 

(i) (1) Small business exemptions. Vehicles and engines produced by small business 

manufacturers meeting the criteria in 13 CFR part 121.201 are exempted from the 

requirements of this regulation but are required to provide to EPA a statement explaining 

how they qualify as a . Qualifying small business as defined by the Small Business 

Administration at 13 CFR 121.201. The statement must be submitted to the 

manufacturers must notify the EPA and NHTSA Administrators of EPA before importing 

or introducing any excluded vehicle into U.S. commerce as specified in §1036.150 and 

§1037.150.

(ii) Off-road exclusion (tractors and vocational vehicles only). Vehicles intended to 

be used extensively in off-road environments such as forests, oil fields, and construction 

sites may be exempted from the requirements of this part if EPA and NHTSA approve 

the exemption. This provision applies to all heavy-duty vehicles except for vocational 

trucks and truck tractors meeting the qualifications specified in 49vehicles or engines. 

This notification must include a description of the manufacturer’s qualification as a small 

business under 13 CFR 523.2 that are already exempted. Manufacturers seeking an 

exemption must send the request to the Administrators of 121.201 and must be submitted 

to EPA explaining the basis for defining their vehicle for exclusive use as an off-road 

vehicle as specified in §1036.630 and §1037.630. The manufacturer must send a request 

to EPA before submitting its first application for a certificate of conformity. . The 

agencies may review a manufacturer’s qualification as a small business manufacturer 

under 13 CFR 121.201.

(iii) Incentive for(2) Early Introduction. The provision applies to manufacturers 

seeking to comply early compliancewith the NHTSA’s fuel consumption program prior 

to model year 2014. The manufacturer must send the request to EPA before submitting 

its first application for a certificate of conformity. 

(iv3) NHTSA Voluntary Compliance Model Years. Manufacturers must submit a 

statement declaring whether the manufacturer chooses to comply voluntarily with 

NHTSA’s fuel consumption standards for model years 2014 through 2015. The 

manufacturers must acknowledge that once selected, the decision cannot be reversed and 

the manufacturer will continue to comply with the fuel consumption standards for 

subsequent model years. The manufacturer must send the statement to EPA before 

submitting its first application for a certificate of conformity. 
(v) Exemption from EOY reports. Manufactures4) Alternative engine standards. 

Manufacturers choosing to comply with a surplus of the alternative engine standards must 

notify EPA and NHTSA of their choice and include in that notification a demonstration 

that it has exhausted all available credits and credit canopportunities. The manufacturer 

must send a request to be exempted from provide an the statement to EPA before 

submitting its EOY report. The request must be submitted to EPA 

(5) Alternate phase-in. Manufacturers choosing to comply with the alternative 

engine phase-in must notify EPA and NHTSA of their choice. The manufacturer must 

send the statement to EPA before submitting its first application for a certificate of 

conformity. 

(6) Off-road exclusion (tractors and vocational vehicles only). (i) Vehicles intended 

to be used extensively in off-road environments such as forests, oil fields, and 

construction sites may be exempted without request from the requirements of this 

regulation as specified in 49 CFR 523.2 and § 535.5(b). Within 90 days after the end of 

each model year had ended. , manufacturers must send EPA and NHTSA through the 

EPA database a report with the following information:

(vi(A) A description of each excluded vehicle configuration, including an 

explanation of why it qualifies for this exclusion.

(B) The number of vehicles excluded for each vehicle configuration. 

(ii) A manufacturer having an off-road vehicle failing to meet the criteria under the 

agencies’ off-road exclusions will be allowed to submit a petition describing how and 

why their vehicles should qualify for exclusion. The process of petitioning for an 

exclusion is explained below. For each request, the manufacturer will be required to 

describe why it believes an exclusion is warranted and address following factors which 

the agencies will consider in granting its petition: 

(A) The agencies will provide an exclusion based on off road capability of the 

vehicle or if the vehicle is fitted with speed restricted tires. A manufacturer should 

explain which exclusion does its vehicle qualify under; and

(B) A manufactures should verify if there any comparable tires that exist in the 

market to carry out the desired application both on and off road for the subject vehicle(s) 

of the petition which have LLR values that would enable compliance with the standard.

(7) Vocational Tractor. Tractors intended to be used as vocational tractors may 

comply with vocational vehicle standards in Part 535.5(b) of this regulation. 

Manufacturers classifying tractor as vocational tractors must provide a description of how 

they meet the qualifications in their applications for certificates of conformity as 

specified in 40 CFR part 1037.205. 

(8) Approval of alternate methods to determine drag coefficients (tractors only). 

Manufacturers seeking to use alternative methods to determine aerodynamic drag 

coefficients must provide a request and gain approval by EPA. The manufacturer must 

send the request to EPA before submitting its first application for a certificate of 

conformity. 

(vii) Alternative Engine Standards (engines only). Manufacturers seeking to use the 

alternative engine standards must submit a request and be given approval by EPA with 90 

days after the model year had ended. 
(viii) Alternative Engine Phase-in (engines only). Manufacturers choosing to use the 

alternative engine phase-in must alert EPA to the decision. The manufacturer must send 

a statement to EPA before submitting its first application for a certificate of conformity. 

(9) Innovative Technology Credits. Manufacturers pursuing innovative technology 

credits must submit information to the agencies and may be subject to a public evaluation 

process in which the public would have opportunity for comment if not using a test 

procedure in accordance with 40 CFR part 1037.610(c). Whether the approach involves

on-road testing, modeling, or some other analytical approach, the manufacturer would be 

required to present a final methodology to EPA and NHTSA. EPA and NHTSA would 

approve the methodology and credits only if certain criteria were met. Baseline 

emissions and fuel consumption and control emissions and fuel consumption would need 

to be clearly demonstrated over a wide range of real world driving conditions and over a 

sufficient number of vehicles to address issues of uncertainty with the data. Data would 

need to be on a vehicle model-specific basis unless a manufacturer demonstrated modelspecific data was not necessary. The agencies may publish a notice of availability in the 

Federal Register notifying the public of a manufacturer’s proposed alternative off-cycle 

credit calculation methodology and provide opportunity for comment. Any notice will 

include details regarding the methodology, but not include any Confidential Business 

Information.

(10) If a manufacturer trades fuel consumption credits, it must send EPA a report 

within 90 days after the transaction, as follows:

(i) As the seller, the manufacturer must include the following information in its 

report:

(A) The corporate names of the buyer and any brokers.

(B) A copy of any contracts related to the trade.

(C) The fleet, vehicle or engine families that generated fuel consumption credits for 

the trade, including the number of fuel consumption credits from each family.

(ii) As the buyer, the manufacturer or entity must include the following information in 

its report:

(A) The corporate names of the seller and any brokers.

(B) A copy of any contracts related to the trade.

(C) How the manufacturer or entity intends to use the fuel consumption credits, 

including the number of fuel consumption credits it intends to apply to each vehicle 

family (if known).

(i) Public Information. Based upon information submitted by manufacturers and 

EPA, NHTSA will publish fuel consumption standards and performance results. 

 (j) Information received from EPA. NHTSA will receive information from EPA as 

specified in 40 CFR part1036.755 and 40 CFR part 1037.755. 

§535.9 Enforcement Approach. 

(a) Compliance. (1) NHTSA assesseswill assess compliance with fuel consumption 

standards each year, utilizing the certified and reported fuel consumption data provided 

by the Environmental Protection Agency based upon EPA final verified data submitted to 

NHTSA for enforcement of the its heavy-duty truckvehicle fuel efficiency program 

established pursuant to 49 U.S.C. 32902(k). NHTSA may conduct verification testing 
throughout a given model year in order to validate data received from manufacturers and 

will discuss any potential issues with EPA and the manufacturer. 

(2) Credit values in gallons are calculated based on the final CO2 emissions and fuel 

consumption data submitted by manufacturers and verified/validated by EPA. 

(3) If NHTSA will verify a manufacturer’s regulatory subcategory fuel 

consumptioncredit balance in any each averaging set for each given model year. The 

average set balance is found to exceedbased upon the engines or vehicles performance 

above or below the applicable standard(s), NHTSA identifies surplus regulatory 

subcategory standards in each respective averaging set and any credits in a manufacturer's 

account for that are traded into or out of an averaging set during the model year and 

regulatory subcategory in the appropriate amount by which. 

(i) If the balance is positive, the manufacturer has exceeded the applicable 

standard(s).is designated as having a credit surplus.

(4) ii) If a manufacturer's engines or vehicles inthe balance is negative, the 

manufacturer is designated as having a particular regulatory subcategory are found not to 

meet the applicable fuel consumption standard(s), calculated as a credit shortfall,credit 

deficit. 

(4) NHTSA will provide written notification to the manufacturer that it has failed to 

meet a particular regulatory subcategory standard.has a negative balance for any 

averaging set for each model year. The manufacturer will be required to confirm the 

performance shortfall and must either:negative balance and submit a plan indicating how 

it will allocate existing credits or earn, and/or acquire by trade credits;, or willelse be 

liable for a civil penalty as determined in paragraph (b) of this section. The manufacturer 

must submit a plan within 60 days of receiving agency notification. 

 (5) Credit shortfall within a regulatory subcategoryan averaging set may be carried 

forward only three years, and if not offset by earned or traded credits, the manufacturer 

may be liable for a civil penalty as described in paragraph (b) of this section. 

 (6) Credit allocation plans received from a manufacturer will be reviewed and 

approved by NHTSA. NHTSA will approve a credit allocation plan unless it determines 

that the proposed credits are unavailable or that it is unlikely that the plan will result in 

the manufacturer earning sufficient credits to offset the subject credit shortfall. If a plan 

is approved, NHTSA will revise the respective manufacturer's credit account accordingly 

by identifying which existing or traded credits are being used to address the credit 

shortfall, or by identifying the manufacturer’s plan to earn future credits for addressing 

the respective credit shortfall. If a plan is rejected, NHTSA will notify the respective 

manufacturer and request a revised plan. The manufacturer must submit a revised plan 

within 14 days of receiving agency notification. The agency will provide a manufacturer 

one opportunity to submit a revised credit allocation plan before it initiates civil penalty 

proceedings. 

(7) For purposes of this regulation, NHTSA will treat the use of future credits for 

compliance, as through a credit allocation plan, as a deferral of civil penalties for noncompliance with an applicable fuel consumption standard. 

(8) If NHTSA receives and approves a manufacturer's credit allocation plan to earn 

future credits within the following three model years in order to comply with regulatory 

obligations, NHTSA will defer levying civil penalties for non-compliance until the 

date(s) when the manufacturer's approved plan indicates that credits will be earned or 
acquired to achieve compliance, and upon receiving confirmed CO2 emissions and fuel 

consumption data from EPA. If the manufacturer fails to acquire or earn sufficient 

credits by the plan dates, NHTSA will initiate civil penalty proceedings. 

(9) In the event that NHTSA fails to receive or is unable to approve a plan for a noncompliant manufacturer due to insufficiency or untimeliness, NHTSA may initiate civil 

penalty proceedings. 

(10) In the event that a manufacturer fails to report accurate fuel consumption data for 

vehicles or engines covered under this rule, noncompliance will be assumed until 

corrected by submission of the required data, and NHTSA may initiate civil penalty 

proceedings. 

(b) Civil Penalties. (1) Generally. NHTSA may assess a civil penalty for any 

violation of this part under 49 U.S.C. 32902(k). This section states the procedures for 

assessing civil penalties for violations of 49 CFR 535. 5. The provisions of 5 U.S.C. 

554, 556, and 557 do not apply to any proceedings conducted pursuant to this section. 

(2) Initial Determination of Noncompliance. An action for civil penalties is 

commenced by the execution of a Notice of Violation. A determination by NHTSA’s 

Office of Enforcement of noncompliance with applicable fuel consumption standards 

utilizing the certified and reported CO2 emissions and fuel consumption data provided by 

the Environmental Protection Agency as described in this part, and after considering all 

the flexibilities available under § 535.7, underlies a Notice of Violation. If NHTSA 

Enforcement determines that a regulatory subcategorymanufacturer’s averaging set of 

vehicles or engines fails to comply with the applicable fuel consumption standard(s) by 

generating a credit shortfall, the chassis, vehicle or engine manufacturer, as relevant, shall 

be subject to a civil penalty. 

(3) Numbers of Violations and Maximum Civil Penalties. Any violation as defined in 

§ 535.4 shall constitute a separate violation with respect to each vehicle or engine within 

the applicable regulatory subcategory.averaging set. The maximum civil penalty is not 

more than $37,500.00 per vehicle or engine. The maximum civil penalty under this 

section for a related series of violations shall be determined by multiplying $37,500.00 

times the vehicle or engine production volume for the model year in question within the 

regulatory subcategory.averaging set. NHTSA may adjust this civil penalty amount to 

account for inflation. 

 (4) Factors for determining penalty amount. In determining the amount of any civil 

penalty proposed to be assessed or assessed under this section, NHTSA shall take into 

account the gravity of the violation, the size of the violator’s business, the violator’s 

history of compliance with applicable fuel consumption standards, the actual fuel 

consumption performance related to the applicable standards, the estimated cost to 

comply with the regulation and applicable standards, the quantity of vehicles or engines 

not complying, and the effect of the penalty on the violator’s ability to continue in 

business. The “estimated cost to comply with the regulation and applicable standards,” 

will be used to ensure that penalties for non-compliance will not be less than the cost of 

compliance. 

(5) NHTSA enforcement report of determination of non-compliance. (i) If NHTSA 

Enforcement determines that a violation has occurred, NHTSA Enforcement may prepare 

a report and send the report to the NHTSA Chief Counsel. 
(ii) The NHTSA Chief Counsel will review the report prepared by NHTSA 

Enforcement to determine if there is sufficient information to establish a likely violation. 

(iii) If the Chief Counsel determines that a violation has likely occurred, the Chief 

Counsel may issue a Notice of Violation to the party. 

(iv) If the Chief Counsel issues a Notice of Violation, he or she will prepare a case 

file with recommended actions. A record of any prior violations by the same party shall 

be forwarded with the case file. 

(6) Notice of violation. (i) The Notice of Violation will contain the following 

information: 

(A) The name and address of the party; 

(B) The alleged violation(s) and the applicable fuel consumption standard(s) 

violated; 

(C) The amount of the proposed penalty and basis for that amount; 

(D) The place to which, and the manner in which, payment is to be made;

(E) A statement that the party may decline the Notice of Violation and that if the 

Notice of Violation is declined within 30 days of the date shown on the Notice of

Violation, the party has the right to a hearing, if requested within 30 days of the date 

shown on the Notice of Violation, prior to a final assessment of a penalty by a Hearing 

Officer; and 

(F) A statement that failure to either pay the proposed penalty or to decline the 

Notice of Violation and request a hearing within 30 days of the date shown on the Notice 

of Violation will result in a finding of violation by default and that NHTSA will proceed 

with the civil penalty in the amount proposed on the Notice of Violation without 

processing the violation under the hearing procedures set forth in this subpart. 

(ii) The Notice of Violation may be delivered to the party by: 

(A) Mailing to the party (certified mail is not required); 

(B) Use of an overnight or express courier service; or 

(C) Facsimile transmission or electronic mail (with or without attachments) to the 

party or an employee of the party. 

(iii) At any time after the Notice of Violation is issued, NHTSA and the party may 

agree to reach a compromise on the payment amount. 

(iv) Once a penalty amount is paid in full, a finding of “resolved with payment” will 

be entered into the case file. 

(v) If the party agrees to pay the proposed penalty, but has not made payment within 

30 days of the date shown on the Notice of Violation, NHTSA will enter a finding of

violation by default in the matter and NHTSA will proceed with the civil penalty in the 

amount proposed on the Notice of Violation without processing the violation under the

hearing procedures set forth in this subpart. 

(vi) If within 30 days of the date shown on the Notice of Violation a party fails to 

pay the proposed penalty on the Notice of Violation, and fails to request a hearing, then 

NHTSA will enter a finding of violation by default in the case file, and will assess the 

civil penalty in the amount set forth on the Notice of Violation without processing the 

violation under the hearing procedures set forth in this subpart. 

(vii) NHTSA’s order assessing the civil penalty following a party’s default is a final 

agency action. 
(7) Hearing Officer. (i) If a party timely requests a hearing after receiving a Notice

of Violation, a Hearing Officer shall hear the case. 

(ii) The Hearing Officer will be appointed by the NHTSA Administrator, and is 

solely responsible for the case referred to him or her. The Hearing Officer shall have no 

other responsibility, direct or supervisory, for the investigation of cases referred for the 

assessment of civil penalties. The Hearing Officer shall have no duties related to the 

light-duty fuel economy or medium- and heavy-duty fuel efficiency programs. 

(iii) The Hearing Officer decides each case on the basis of the information before 

him or her. 

 (8) Initiation of action before the Hearing Officer. (i) After the Hearing Officer 

receives the case file from the Chief Counsel, the Hearing Officer notifies the party in 

writing of: 

(A) The date, time, and location of the hearing and whether the hearing will be 

conducted telephonically or at the DOT Headquarters building in Washington, DC; 

(B) The right to be represented at all stages of the proceeding by counsel as set forth 

in the paragraph (b)(9) of this section; 

(C) The right to a free copy of all written evidence in the case file.

(ii) On the request of a party, or at the Hearing Officer’s direction, multiple 

proceedings may be consolidated if at any time it appears that such consolidation is 

necessary or desirable. 

(9) Counsel. A party has the right to be represented at all stages of the proceeding by 

counsel. A party electing to be represented by counsel must notify the Hearing Officer of 

this election in writing, after which point the Hearing Officer will direct all further 

communications to that counsel. A party represented by counsel bears all of its own 

attorneys’ fees and costs. 

(10) Hearing location and costs. (i) Unless the party requests a hearing at which the 

party appears before the Hearing Officer in Washington, DC, the hearing may be held 

telephonically. In Washington, DC, the hearing is held at the headquarters of the U.S. 

Department of Transportation. 

(ii) The Hearing Officer may transfer a case to another Hearing Officer at a party’s 

request or at the Hearing Officer’s direction. 

(iii) A party is responsible for all fees and costs (including attorneys’ fees and costs, 

and costs that may be associated with travel or accommodations) associated with 

attending a hearing. 

(11) Hearing procedures. (i) There is no right to discovery in any proceedings 

conducted pursuant to this subpart. 

(ii) The material in the case file pertinent to the issues to be determined by the 

Hearing Officer is presented by the Chief Counsel or his or her designee. 

(iii) The Chief Counsel may supplement the case file with information prior to the 

hearing. A copy of such information will be provided to the party no later than 3 

business days before the hearing. 

(iv) At the close of the Chief Counsel’s presentation of evidence, the party has the 

right to examine respond to and rebut material in the case file and other information 

presented by the Chief Counsel. In the case of witness testimony, both parties have the 

right of cross-examination. 
(v) In receiving evidence, the Hearing Officer is not bound by strict rules of 

evidence. In evaluating the evidence presented, the Hearing Officer must give due 

consideration to the reliability and relevance of each item of evidence. 

(vi) At the close of the party’s presentation of evidence, the Hearing Officer may 

allow the introduction of rebuttal evidence that may be presented by the Chief Counsel. 

(vii) The Hearing Officer may allow the party to respond to any rebuttal evidence 

submitted. 

(viii) After the evidence in the case has been presented, the Chief Counsel and the 

party may present arguments on the issues in the case. The party may also request an 

opportunity to submit a written statement for consideration by the Hearing Officer and 

for further review. If granted, the Hearing Officer shall allow a reasonable time for 

submission of the statement and shall specify the date by which it must be received. If 

the statement is not received within the time prescribed, or within the limits of any 

extension of time granted by the Hearing Officer, it need not be considered by the 

Hearing Officer. 

(viiiix) A verbatim transcript of the hearing will not normally be prepared. A party 

may, solely at its own expense, cause a verbatim transcript to be made. If a verbatim 

transcript is made, the party shall submit two copies to the Hearing Officer not later than 

15 days after the hearing. The Hearing Officer shall include such transcript in the record. 

(12) Determination of Violations and Assessment of Civil Penalties. (i) Not later than 

30 days following the close of the hearing, the Hearing Officer shall issue a written 

decision on the Notice of Violation, based on the hearing record. This may be extended 

by the Hearing officer if the submissions by the Chief Counsel or the party are 

voluminous. The decision shall address each alleged violation, and may do so 

collectively. For each alleged violation, the decision shall find a violation or no violation 

and provide a basis for the finding. The decision shall set forth the basis for the Hearing 

Officer’s assessment of a civil penalty, or decision not to assess a civil penalty. In 

determining the amount of the civil penalty, the gravity of the violation, the size of the 

violator’s business, the violator’s history of compliance with applicable fuel consumption 

standards, the actual fuel consumption performance related to the applicable standard, the 

estimated cost to comply with the regulation and applicable standard, the quantity of 

vehicles or engines not complying, and the effect of the penalty on the violator’s ability 

to continue in business. The assessment of a civil penalty by the Hearing Officer shall be 

set forth in an accompanying final order. The Hearing Officer’s written final order is a 

final agency action. 

(ii) If the Hearing Officer assesses civil penalties in excess of $1,000,000, the 

Hearing Officer’s decision shall contain a statement advising the party of the right to an 

administrative appeal to the Administrator within a specified period of time. The party is 

advised that failure to submit an appeal within the prescribed time will bar its 

consideration and that failure to appeal on the basis of a particular issue will constitute a 

waiver of that issue in its appeal before the Administrator.

(iii) The filing of a timely and complete appeal to the Administrator of a Hearing 

Officer’s order assessing a civil penalty shall suspend the operation of the Hearing 

Officer’s penalty, which shall no longer be a final agency action. 

(iv) There shall be no administrative appeals of civil penalties assessed by a Hearing 

Officer of less than $1,000,000. 
(13) Appeals of civil penalties in excess of $1,000,000. (i) A party may appeal the 

Hearing Officer’s order assessing civil penalties over $1,000,000 to the Administrator 

within 21 days of the date of the issuance of the Hearing Officer’s order. 

(ii) The Administrator will review the decision of the Hearing Officer de novo, and 

may affirm the decision of the hearing officer and assess a civil penalty, or 

(iii) The Administrator may: 

(A) Modify a civil penalty; 

(B) Rescind the Notice of Violation; or 

(C) Remand the case back to the Hearing Officer for new or additional proceedings. 

(iv) In the absence of a remand, the decision of the Administrator in an appeal is a 

final agency action. 

(14) Collection of assessed or compromised civil penalties. (i) Payment of a civil 

penalty, whether assessed or compromised, shall be made by check, postal money order, 

or electronic transfer of funds, as provided in instructions by the agency. A payment of 

civil penalties shall not be considered a request for a hearing. 

(ii) The party must remit payment of any assessed civil penalty to NHTSA within 30 

days after receipt of the Hearing Officer’s order assessing civil penalties, or, in the case 

of an appeal to the Administrator, within 30 days after receipt of the Administrator’s 

decision on the appeal. 

(iii) The party must remit payment of any compromised civil penalty to NHTSA on 

the date and under such terms and conditions as agreed to by the party and NHTSA. 

Failure to pay may result in NHTSA entering a finding of violation by default and 

assessing a civil penalty in the amount proposed in the Notice of Violation without 

processing the violation under the hearing procedures set forth in this part.

(c) Changes in corporate ownership and control. Manufacturers must inform 

NHTSA of corporate relationship changes to ensure that credit accounts are identified 

correctly and credits are assigned and allocated properly. 

(1) In general, if two manufacturers merge in any way, they must inform NHTSA 

how they plan to merge their credit accounts. NHTSA will subsequently assess corporate 

fuel consumption and compliance status of the merged fleet instead of the original 

separate fleets. 

(2) If a manufacturer divides or divests itself of a portion of its automobile 

manufacturing business, it must inform NHTSA how it plans to divide the manufacturer's 

credit holdings into two or more accounts. NHTSA will subsequently distribute holdings 

as directed by the manufacturer, subject to provision for reasonably anticipated 

compliance obligations. 

(3) If a manufacturer is a successor to another manufacturer's business, it must 

inform NHTSA how it plans to allocate credits and resolve liabilities per 49 CFR part 

534. 

 

Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Mediumand Heavy-Duty Engines and Vehicles: Final Rules 
Dated: _______________________ 

_____________________________________________________ 

Ray LaHood, Secretary, Department of Transportation 

 
Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Mediumand Heavy-Duty Engines and Vehicles: Final Rules 

Dated: _______________________ 

_____________________________________________________ 

Lisa P. Jackson, Administrator, Environmental Protection Agency