Summary of interagency working comments received on draft rule under EO 12866 

review and EO 13563 review. Subject to further policy review. 

1 

Below is a summary of interagency comments received during EO 12866 and EO 13563 review 

of the draft final rule establishing GHG emissions standards and fuel efficiency standards for 

medium and heavy duty trucks. They are for your consideration and subject to further policy 

review. 

1) Alternative Fuels Discussion for Preamble. Interagency commenters recommend that the 

agencies incorporate the following language into the Preamble: 

This combined rulemaking by EPA and NHTSA is designed to regulate two separate 

characteristics of heavy duty vehicles: greenhouse gas emissions and fuel consumption. 

In the case of diesel or gasoline powered vehicles, there is a one-to-one relationship 

between these two characteristics. Each gallon of gasoline combusted by a truck engine 

generates approximately 8,887 grams of CO2; and each gallon of diesel fuel burned 

generates about 10,180 grams of CO2. Because no available technologies reduce CO2 

emissions per gallon of fuel combusted, any rule that limits CO2 emissions is effectively 

identical to a rule that limits fuel consumption. Compliance by a truck manufacturer with 

the NHTSA fuel economy rule assures compliance with the EPA rule, and vice versa. 

For alternatively fueled vehicles, which use no petroleum, the situation is different. For 

example, a natural gas vehicle that achieves approximately the same fuel economy as a 

diesel powered vehicle would emit 20 percent less CO2; and a natural gas vehicle with 

the same fuel economy as a gasoline vehicle would emit 30 percent less CO2. Yet 

natural gas vehicles consume no petroleum. To the extent that the goal of the NHTSA 

fuel economy portion of this rulemaking is to curb petroleum use, then natural gas 

vehicles should be credited with zero fuel consumption per mile. Similar differences 

between oil consumption and greenhouse gas emissions would apply to electric vehicles, 

hybrid electric vehicles, and biofuel-powered vehicles. 

In recent rulemakings for light-duty vehicles, EPA and NHTSA have followed the 

statutory provision that treats one gallon of alternative fuel as equivalent to 0.15 gallons 

of gasoline. Following that precedent in this heavy duty rule would mean that, for 

example, a natural gas powered truck would have attributed to it 20 percent less CO2 

emissions than a comparable diesel powered truck, but 85 percent less fuel consumption. 

Engine manufacturers with a relatively large share of alternative-fuel products would 

likely have an easier time complying with NHTSAs average fuel economy standard than 

EPAs greenhouse gas emissions standard. Similarly, engine manufacturers with a 

relatively small share of alternative-fuel products would have a relatively easier time 

complying with EPA’s CO2 standard than with NHTSA’s fuel economy standard. In 

that way, the rule would not differ from the light duty vehicle rules. 
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Instead, in this rule, EPA and NHTSA are finalizing identical rules. Fuel consumption 

for alternatively-powered vehicles will be calculated according to their CO2 emissions. 

In that way, there will be a one-to-one relationship between fuel economy and 

greenhouse gas emissions for all vehicles, by design, whether or not that relationship 

accurately reflects true fuel consumption and CO2 emissions. This has the advantage of 

reducing some of the paperwork and compliance burden this rule will impose on the truck 

manufacturers. On the other hand, it has the disadvantage of discouraging some costeffective means of reducing petroleum consumption by trucks, and the accompanying 

energy security costs. By attributing to natural gas engines only 20 percent less fuel 

consumption than comparable diesel engines, because they emit 20 percent less CO2, 

rather than attributing to them a much larger percentage reduction in fuel consumption, 

because they use no petroleum, this uniform rulemaking disincentivizes technologies that 

reduce consumption of petroleum-based fuels. 

Agencies are considering for future rulemakings writing harmonized standards in a way 

that accurately reflect the true fuel consumption and greenhouse gas emissions. Under 

such standards, any given vehicle might “over comply” with the fuel economy standard, 

but might “under comply” with the CO2 standard. Therefore, in meeting the fleet-wide 

requirements, a manufacturer would need to meet both standards using all available 

options, such as credit trading and technology mix. Allowing for two distinct standards 

would enable manufacturers to achieve the twin goals of reducing greenhouse gas 

emissions and decreasing consumption of petroleum-based fuels in the most costeffective manner. 

2) EPA and DOT agreed to include fuel savings as a separate category when presenting 

them in tables. However, the latest draft of the Preamble still includes fuel savings as part 

of costs (as negative costs). Interagency comments request that agencies separate fuel 

savings from cost categories. 

3) Pages 8-9 of revised Preamble- Interagency commenters recommend discussing energy 

and national security and then discussing climate change. These edits reflect idea of 

having fuel consumption first and then ghgs. Interagency commenters note that this 

ordering fits with the President’s memo (eg, “America has the opportunity to lead the 

world in the development of a new generation of clean cars and trucks through innovative 

technologies and manufacturing that will spur economic growth and create high-quality 

domestic jobs, enhance our energy security, and improve our environment.” and also 

“While the Federal Government and many States have now created a harmonized 

framework for addressing the fuel economy of and greenhouse gas emissions from cars 

and light-duty trucks, medium- and heavy-duty trucks and buses continue to be a major 

source of fossil fuel consumption and greenhouse gas pollution”
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4) Commenters recommend that agencies adopt the following language on Page 294:

Finally, the diversity of vehicle types and useful lives does not pose a problem for credit 

trading. Each gram of carbon abated or gallon of fuel saved has the same benefit, 

regardless of whether it is saved due to technological advances in a pickup truck, 

vocational vehicle, or tractor, and regardless of whether it is saved by advances in the 

engines or bodies. The EPA and NHTSA formulas estimate the useful life of vehicles to 

translate grams per mile, gramps per bhp-hr, and grams per ton-mile into lifetime tons of 

CO2, and equivalently gallons per mile, bhp-hr, and ton-mile into total lifetime gallons. 

If the EPA/ NHTSA formulas are overstate or understate vehicles’ useful lives, then this 

rule may achieve more or less CO2 reduction and fuel savings than projected. If the 

agencies overstate the useful lives of a truck, less CO2 abatement and fuel savings will be 

achieved. If the agencies understate the useful life, more will be achieved. This is true 

regardless of whether trading occurs or not. In the presence of flexible trading 

provisions, if the agencies understate the useful life of a truck with relatively high 

compliance costs, and truck makers in that category purchase credits from truck makers 

in a category where the agencies have overestimated the useful life, then the trading will 

result in more pollution abatement and fuel savings than projected. If the reverse is true, 

and the agencies overstate the useful life of trucks with relatively low compliance costs, 

then trading result in less pollution abatement and fuel savings than projected. There is 

no reason to think, however, that errors in the agencies’ calculations would be correlated 

with these regulatory compliance costs, and therefore no reason to restrict trading on the 

basis of diversity of vehicle types or uncertainty in the formulas that translate CO2 

emissions rates and fuel economy into overall CO2 emissions and gallons of fuel. 

Accuracy in these formulas is important, however, and EPA and NHTSA will continue to 

monitor truck performance to make sure the formulas correctly represent fuel economy 

and environmental gains. 

5) Suggested Preamble edits. These edits reflect idea of having fuel consumption first and 

then ghgs. Interagency commenters note that this ordering fits with the President’s memo 

(eg, “America has the opportunity to lead the world in the development of a new 

generation of clean cars and trucks through innovative technologies and manufacturing 

that will spur economic growth and create high-quality domestic jobs, enhance our 

energy security, and improve our environment.” and also “While the Federal Government 

and many States have now created a harmonized framework for addressing the fuel 

economy of and greenhouse gas emissions from cars and light-duty trucks, medium- and 

heavy-duty trucks and buses continue to be a major source of fossil fuel consumption and 

greenhouse gas pollution”
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ENVIRONMENTAL PROTECTION AGENCY 

40 CFR Parts 85, 86, 600, 1036, 1037, 1039, 1065, 1066, and 1068 

DEPARTMENT OF TRANSPORTATION 

National Highway Traffic Safety Administration 

49 CFR Parts 523, 534, and 535 

[EPA–HQ–OAR–2010–0162; NHTSA-2010-0079; FRL-xxxx-x] 

RIN 2060-AP61; RIN 2127-AK74 

Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium- and HeavyDuty Engines and Vehicles 

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

Administration (NHTSA) 

ACTION: Final Rules 

__________________________________________________________________ 

SUMMARY: 

EPA and NHTSA, on behalf of the Department of Transportation, are each finalizing rules to 

establish a comprehensive Heavy-Duty National Program that will significantly reduce fuel 

consumption and greenhouse gas emissions for on-road heavy-duty vehicles, responding to the 

President’s directive on May 21, 2010, to take coordinated steps to produce a new generation of 

clean vehicles. NHTSA’s final fuel consumption standards and EPA’s final carbon dioxide 

(CO2) emissions standards are tailored to each of three regulatory categories of heavy-duty 

vehicles: (1) Combination Tractors; (2) Heavy-duty Pickup Trucks and Vans; and (3) 

Vocational Vehicles. The rules include separate standards for the engines that power 

combination tractors and vocational vehicles. Certain rules are exclusive to the EPA program. 

These include EPA’s final hydrofluorocarbon emissions standards to control leakage from air 

conditioning systems in combination tractors, and pickup trucks and vans. These also include 

EPA’s final nitrous oxide (N2O) and methane (CH4) emissions standards that will apply to all 

heavy-duty engines, pickup trucks and vans. EPA is also finalizing provisions allowing lightduty vehicle manufacturers to use CO2 credits to meet the light-duty vehicle N2O and CH4

standards, and a technical amendment to the criteria pollutant emissions requirements for certain 

switch locomotives. 
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EPA’s final greenhouse gas emission standards under the Clean Air Act will begin with model 

year 2014. NHTSA’s final fuel consumption standards under the Energy Independence and 

Security Act of 2007 will be voluntary in model years 2014 and 2015, becoming mandatory with 

model year 2016 for most regulatory categories. Commercial trailers are not regulated in this 

phase of the Heavy-Duty National Program. 

The agencies estimate that the combined standards will reduce CO2 emissions by approximately 

280 million metric tons and save over 500 million barrels of oil over the life of vehicles sold 

during the 2014 through 2018 model years, providing over $7 billion in net societal benefits, and 

$49 billion in net societal benefits when private fuel savings are considered. 

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

Federal Register], sixty days after date of publication in the Federal Register. The 

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

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

Register]. 

ADDRESSES: EPA and NHTSA have established dockets for this action under Docket ID No. 

EPA–HQ–OAR–2010–0162 and NHTSA-2010-0079, respectively. All documents in the docket 

are listed on the www.regulations.gov web site. Although listed in the index, some information is 

not publicly available, e.g., confidential business information or other information whose 

disclosure is restricted by statute. Certain other material, such as copyrighted material, is not 

placed on the Internet and will be publicly available only in hard copy form. Publicly available 

docket materials are available either electronically through www.regulations.gov or in hard copy 

at the following locations: EPA: EPA Docket Center, EPA/DC, EPA West Building, 1301 

Constitution Ave., N.W., Room 3334, Washington DC. The Public Reading Room is open from 

8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number 

for the Public Reading Room is (202) 566–1744, and the telephone number for the Air Docket is 

(202) 566-1742. NHTSA: Docket Management Facility, M-30, U.S. Department of 

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

Washington, DC 20590. The Docket Management Facility is open between 9 a.m. and 5 p.m. 

Eastern Time, Monday through Friday, except Federal holidays. 

FOR FURTHER INFORMATION CONTACT: NHTSA: Lily Smith, Office of Chief 

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

Washington, DC 20590. Telephone: (202) 366-0949. EPA: Lauren Steele, Office of 

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

Protection Agency, 2000 Traverwood Drive, Ann Arbor, MI 48105; telephone number: (734) 

214-4788; fax number: (734) 214-4816; email address: steele.lauren@epa.gov, or contact the 

Assessment and Standards Division, email OTAQPUBLICWEB@epa.gov. 
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SUPPLEMENTARY INFORMATION: 

A. Does this Action Apply to Me 

This action affects companies that manufacture, sell, or import into the United States new heavyduty engines and new Class 2b through 8 trucks, including combination tractors, school and 

transit buses, vocational vehicles such as utility service trucks, as well as 3⁄4-ton and 1-ton pickup 

trucks and vans. The heavy-duty category incorporates all motor vehicles with a gross vehicle 

weight rating of 8,500 pounds or greater, and the engines that power them, except for mediumduty passenger vehicles already covered by the greenhouse gas emissions standards and 

corporate average fuel economy standards issued for light-duty model year 2012-2016 vehicles. 

Regulated categories and entities include the following: 

Category NAICS Codea

 Examples of Potentially Affected Entities 

Industry 336111 Motor Vehicle Manufacturers, Engine and 

336112 Truck Manufacturers 

336120 

Industry 541514 Commercial Importers of Vehicles and 

811112 Vehicle Components 

811198 

Industry 336111 Alternative Fuel Vehicle Converters 

336112 

422720 

454312 

541514 

541690 

811198 

Note: 

a

 North American Industry Classification System (NAICS) 

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

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

aware may be regulated by this action. Other types of entities not listed in the table could also be 

regulated. To determine whether your activities are regulated by this action, you should 

carefully examine the applicability criteria in the referenced regulations. You may direct 

questions regarding the applicability of this action to the persons listed in the preceding FOR 

FURTHER INFORMATION CONTACT section. 

Table of Contents
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A. Does this Action Apply to Me

I. Overview

A. Introduction

B. Building Blocks of the Heavy-duty National Program

C. Summary of the Final EPA and NHTSA HD National Program

D. Summary of Costs and Benefits of the HD National Program

E. Program Flexibilities

F. EPA and NHTSA Statutory Authorities

G. Future HD GHG and Fuel Consumption Rulemakings

II. Final GHG and Fuel Consumption Standards for Heavy-duty Engines and Vehicles

A. What Vehicles Will Be Affected?

B. Class 7 and 8 Combination Tractors

C. Heavy-Duty Pickup Trucks and Vans

D. Class 2b-8 Vocational Vehicles

E. Other Standards Provisions

III. Feasibility Assessments and Conclusions

A. Class 7-8 Combination Tractor

B. Heavy-Duty Pickup Trucks and Vans

C. Class 2b-8 Vocational Vehicles

IV. Final Regulatory Flexibility Provisions

A. Averaging, Banking, and Trading Program

B. Additional Flexibility Provisions
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V. NHTSA and EPA Compliance, Certification, and Enforcement Provisions

A. Overview

B. Heavy-duty Pickup Trucks and Vans

C. Heavy-Duty Engines

D. Class 7 and 8 Combination Tractors

E. Class 2b-8 Vocational Vehicles

F. General Regulatory Provisions

G. Penalties

VI. How Will This Program Impact Fuel Consumption, GHG Emissions, and Climate 

Change?

A. What Methodologies Did the Agencies Use to Project GHG Emissions and Fuel 

Consumption Impacts?

B. MOVES Analysis

C. What Are the Projected Reductions in Fuel Consumption and GHG Emissions?

D. Overview of Climate Change Impacts from GHG Emissions

E. Changes in Atmospheric CO2 Concentrations, Global Mean Temperature, Sea Level 

Rise, and Ocean pH Associated with the Program’s GHG Emissions Reductions

VII. How Will This Final Action Impact Non-GHG Emissions and Their Associated 

Effects?

A. Emissions Inventory Impacts

B. Health Effects of Non-GHG Pollutants

C. Environmental Effects of Non-GHG Pollutants

D. Air Quality Impacts of Non-GHG Pollutants

VIII. What are the Agencies’ Estimated Cost, Economic, and Other Impacts of the Final 

Program?
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A. Conceptual Framework for Evaluating Impacts

B. Costs Associated With the Final Program

C. Indirect Cost Multipliers

D. Cost per Ton of Emissions Reductions

E. Impacts of Reduction in Fuel Consumption

F. Class Shifting and Fleet Turnover Impacts

G. Benefits of Reducing CO2 Emissions

H. Non-GHG Health and Environmental Impacts

I. Energy Security Impacts

J. Other Impacts

K. The Effect of Safety Standards and Voluntary Safety Improvements on Vehicle 

Weight

L. Summary of Costs and Benefits from the Greenhouse Gas Emissions Perspective

M. Summary of Costs and Benefits from the Fuel Efficiency Perspective

N. Employment Impacts

IX. Analysis of the Alternatives

A. What Are the Alternatives that the Agencies Considered?

B. How Do These Alternatives Compare in Overall GHG Emissions Reductions and 

Fuel Efficiency and Cost?

C. What Is the Agencies’ Decision Regarding Trailer Standards?

X. Public Participation

XI. NHTSA’s Record of Decision

A. The Agency’s Decision
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B. Alternatives Considered by NHTSA in Reaching its Decision, Including the 

Environmentally Preferable Alternative

C. Factors Balanced by NHTSA in Making its Decision

D. How the Factors and Considerations Balanced by NHTSA Entered into its Decision

E. The Agency’s Preferences among Alternatives Based on Relevant Factors, 

Including Economic and Technical Considerations and Agency Statutory Missions

F. Mitigation

XII. Statutory and Executive Order Reviews

XIII. Statutory Provisions and Legal Authority

A. EPA

B. NHTSA

List of Subjects

I. Overview 

A. Introduction 

EPA and NHTSA (“the agencies”) are announcing a first-ever program to improve fuel 

consumption (and thus increase energy security) and to reduce greenhouse gas (GHG) emissions 

in the heavy-duty highway vehicle sector. This broad sector – ranging from large pickups to 

sleeper-cab tractors – together represent the second largest contributor to oil consumption and 

GHG emissions from the mobile source sector, after light-duty passenger cars and trucks. These 

are the second joint rules issued by the agencies, following on the April 1, 2010 standards to 

sharply reduce GHG emissions and fuel consumption from MY 2012-2016 passenger cars and 

light trucks (published on May 7, 2010 at 75 FR 25324. 

In a May 21, 2010 memorandum to the Administrators of EPA and NHTSA (and the 

Secretaries of Transportation and Energy), the President stated that “America has the opportunity 

to lead the world in the development of a new generation of clean cars and trucks through 

innovative technologies and manufacturing that will spur economic growth and create high-
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quality domestic jobs, enhance our energy security, and improve our environment.” 1,2 In the 

May 2010 memorandum, the President specifically requested the Administrators of EPA and 

NHTSA to “immediately begin work on a joint rulemaking under the Clean Air Act (CAA) and 

the Energy Independence and Security Act of 2007 (EISA) to establish fuel efficiency and 

greenhouse gas emissions standards for commercial medium-and heavy-duty on-highway 

vehicles and work trucks beginning with the 2014 model year (MY).” In this final rulemaking 

each agency is addressing this Memorandum by adopting rules under its respective authority that 

together comprise a coordinated and comprehensive HD National Program designed to address 

the urgent and closely intertwined challenges of reduction of dependence on oil, achievement of 

energy security, and amelioration of global climate change. 

At the same time, the final program will benefit consumers and businesses by reducing 

costs for transporting goods andspur growth in the clean energy sector. 

The HD National Program the agencies are finalizing today reflects a collaborative effort 

between the agencies, a range of public interest nongovernmental organizations (NGOs), the 

state of California and the regulated industry. Consistent with Executive Order 13563, section 

2(c), careful engagement long preceded issuance of the NPRM. At the time of the President’s 

announcement, a number of major HD truck and engine manufacturers representing the vast 

majority of this industry, and the California Air Resources Board (California ARB), sent letters 

to EPA and NHTSA supporting the creation of a HD National Program based on a common set 

of principles. In the letters, the stakeholders committed to working with the agencies and with 

other stakeholders toward a program consistent with common principles, including: 

 Increased use of existing technologies to achieve significant GHG emissions and fuel 

consumption reductions; 

 A program that starts in 2014 and is fully phased in by 2018; 

 A program that works towards harmonization of methods for determining a vehicle’s GHG 

and fuel efficiency, recognizing the global nature of the issues and the industry; 

 Standards that recognize the commercial needs of the trucking industry; and 

 Incentives leading to the early introduction of advanced technologies. 

 1

 Improving Energy Security, American Competitiveness and Job Creation, and Environmental Protection Through a 

Transformation of Our Nation’s Fleet of Cars And Trucks,” Issued May 21, 2010, published at 75 FR 29399, May 

26, 2010. 

2

 The May 2010 Presidential Memorandum also directed EPA and NHTSA, in close coordination with the California 

Air Resources Board, to build on the National Program for 2012-2016 MY light-duty vehicles by developing and 

proposing coordinated light-duty vehicle standards for MY 2017-2025. The agencies have taken an initial step in 

this process, releasing a Joint Notice of Intent and Initial Joint Technical Assessment Report in September 2010 (75 

FR 62739), and a Supplemental Notice of Intent (75 FR 76337). The agencies plan to issue a full light-duty vehicle 

proposal to extend the National Program to MY 2017-2025 in September 2011. 
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The final rules adopted today reflect these principles. 

The final HD National Program builds on many years of heavy-duty engine and vehicle 

technology development to achieve what the agencies believe is the greatest degree of GHG 

emission and fuel consumption reduction appropriate, technologically and economically feasible, 

and cost-effective for model years 2014-2018. In addition to taking aggressive steps that are 

reasonably possible now, based on the technological opportunities and pathways that present 

themselves during these model years, the agencies and industry will also continue learning about 

emerging opportunities for this complex sector to further reduce GHG emissions and fuel 

consumption through future regulatory steps. 

Similarly, the agencies will participate in efforts to improve our ability to accurately 

characterize the actual in-use fuel consumption and emissions of this complex sector. As 

technologies progress in the coming years and as the agencies improve the regulatory tools to 

evaluate real world vehicle performance, we expect that we will develop a second phase of 

regulations to reinforce these initial rules and achieve further reductions in GHG emissions and 

fuel consumption reduction for the mid- and longer-term time frame (beyond 2018). The 

agencies are committed to working with all interested stakeholders in this effort and to the extent 

possible working towards alignment with similar programs being developed in Canada, Mexico, 

Europe, China, and Japan. In doing so, we will continue to evaluate many of the structural and 

technical decisions we are making in today’s final action in the context of new technologies and 

the new regulatory tools that we expect to realize in the future. 

The regulatory program we are finalizing today takes careful account of public 

comments, and offers some important improvements, but in key respects, it is not substantially 

different from the proposal the agencies made on November 30, 2010 (see 75 FR 741512). The 

essential structure of the program and the stringency of the standards are essentially the same as 

proposed. We have made a number of changes to the testing requirements and reporting 

requirements to provide greater regulatory certainty and better align the NHTSA and EPA 

portions of the program. In response to comments, and consistent with Executive Order 13563, 

we have also made some changes to the averaging, banking and trading (ABT) provisions of the 

program that will make implementation of this final program more flexible for manufacturers. 

We have added provisions to further encourage the development of advanced technologies and to 

provide a more straightforward mechanism to certify engines and vehicles using innovative 

technologies. Finally in response to comments, we have made some technical changes to our 

emissions compliance model that results in different numeric standards for both combination 

tractors and vocational vehicles to more accurately characterize emissions while maintaining the 

same overall stringency and therefore expected costs and benefits of the program. 

Heavy-duty vehicles move much of the nation’s freight and carry out numerous other 

tasks, including utility work, concrete delivery, fire response, refuse collection, and many more. 

Heavy-duty vehicles are primarily powered by diesel engines, although about 37 percent of these 
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vehicles are powered by gasoline engines.3

 Heavy-duty trucks4 have long been an important part 

of the goods movement infrastructure in this country and have experienced significant growth 

over the last decade related to increased imports and exports of finished goods and increased 

shipping of finished goods to homes through internet purchases. 

The heavy-duty sector is extremely diverse in several respects, including types of 

manufacturing companies involved, the range of sizes of trucks and engines they produce, the 

types of work the trucks are designed to perform, and the regulatory history of different 

subcategories of vehicles and engines. The current heavy-duty fleet encompasses vehicles from 

the “18-wheeler” combination tractors one sees on the highway to school and transit buses, to 

vocational vehicles such as utility service trucks, as well as the largest pickup trucks and vans. 

For purposes of this preamble, the term “heavy-duty” or “HD” is used to apply to all 

highway vehicles and engines that are not within the range of light-duty vehicles, light-duty 

trucks, and medium-duty passenger vehicles (MDPV) covered by the GHG and Corporate 

Average Fuel Economy (CAFE) standards issued for MY 2012-2016.5

 It also does not include 

motorcycles. Thus, in this rulemaking, unless specified otherwise, the heavy-duty category 

incorporates all vehicles with a gross vehicle weight rating above 8,500 pounds, and the engines 

that power them, except for MDPVs.6 

The agencies proposed to cover all segments of the heavy-duty category above, except 

the scopes differ with respect to recreational vehicles (RV’s or motor homes). We note that the 

Energy Independence and Security Act of 2007 requires NHTSA to set standards for 

“commercial medium- and heavy-duty on-highway vehicles and work trucks.”7 The standards 

that EPA is finalizing today cover recreational on-highway vehicles, while NHTSA proposed not 

to include recreational vehicles based on an interpretation of the term “commercial medium- and 

heavy-duty on-highway commercial” vehicles. NHTSA stated in the NPRM that recreational 

vehicles are non-commercial, and therefore outside of the term and the scope of its rule. 

 3

 References in this preamble to “gasoline” engines (and the vehicles powered by them) generally include other 

Otto-cycle engines as well, such as those fueled by ethanol and natural gas, except in contexts that are clearly 

gasoline-specific. 

4

 In this rulemaking, EPA and NHTSA use the term “truck” in a general way, referring to all categories of regulated 

heavy-duty highway vehicles (including buses). As such, the term is generally interchangeable with “heavy-duty 

vehicle.” 

5

 Light-Duty Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel Economy Standards; Final 

Rule 75 FR 25323, May 7, 2010. 

6

 The CAA defines heavy-duty as a truck, bus or other motor vehicles with a gross vehicle weight rating exceeding 

6,000 pounds (CAA section 202(b)(3)). The term HD as used in this action refers to a subset of these vehicles and 

engines. 

7

 49 U.S.C. 32902(k)(2). “Commercial medium- and heavy-duty on-highway vehicles” are defined as on-highway 

vehicles with a gross vehicle weight rating of 10,000 pounds or more, while “work trucks” are defined as vehicles 

rated between 8,500 and 10,000 pounds gross vehicle weight that are not MDPVs. See 49 U.S.C. §§ 32901(a)(7) 

and (a)(19). 
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Oshkosh Corporation commented that this interpretation did not match the statutory 

definition of the term in EISA, which defines “commercial medium- and heavy-duty on-highway 

vehicle” by weight only,8 and that therefore the agency’s interpretation of the term should be 

explicitly broadened to include all vehicles, and more than only vehicles that are not engaged in 

interstate commerce as defined by the Federal Motor Carrier Safety Administration in 49 CFR § 

202. Alternatively, Oshkosh suggested that if NHTSA followed the definition provided in EISA, 

which makes no direct reference to the concept of “commercial,” there would be no logical 

reason to exclude RVs based on that definition. 

NHTSA has considered Oshkosh’s comment and reconsidered its interpretation that 

effectively read words into the statutory definition. Given the very wide variety of vehicles 

contained in the HD fleet, reading those words into the definition and thereby excluding certain 

types of vehicles could create illogical results, i.e., treating similar vehicles differently. 

Therefore, NHTSA will adhere to the statutory definition contained in EISA for this rulemaking. 

However, as RVs were not included by NHTSA in the proposed regulation in the NPRM, they 

are not within the scope and must be excluded in NHTSA’s portion of the final program. 

Accordingly, NHTSA will address this issue in the next rulemaking. 

Setting fuel consumption standards for the heavy-duty sector, pursuant to NHTSA’s 

EISA authority, will improve our energy and national security by reducing our dependence on 

foreign oil, which has been a national objective since the first oil price shocks in the 1970s. Net 

petroleum imports now account for approximately 49-51 percent of U.S. petroleum consumption. 

World crude oil production is highly concentrated, exacerbating the risks of supply disruptions 

and price shocks as the recent unrest in North Africa and the Persian Gulf highlights. Recently, 

oil prices have been over $100 per barrel, gasoline and diesel fuel prices in excess of $4 per 

gallon, causing financial hardship for many families and businesses. The export of U.S. assets in 

exchange for oil imports continues to be an important component of the historically 

unprecedented U.S. trade deficits. Transportation accounts for about 72 percent of U.S. 

petroleum consumption. Heavy-duty vehicles account for about 17 percent of transportation oil 

use, which means that they alone account for about 12 percent of all U.S. oil consumption.9

Setting GHG emissions standards for the heavy-duty sector will also help to ameliorate 

climate change. The EPA Administrator found after a thorough examination of the scientific 

evidence on the causes and impact of current and future climate change, and careful review of 

public comments, that the science compellingly supports a positive finding that atmospheric 

concentrations of these greenhouse gases result in air pollution which may reasonably be 

anticipated to endanger both public health and welfare. In her finding, the Administrator 

carefully studied and relied heavily upon the major findings and conclusions from the recent 

assessments of the U.S. Climate Change Science Program and the U.N. Intergovernmental Panel 

 
Summary of interagency working comments received on draft rule under EO 12866 

review and EO 13563 review. Subject to further policy review. 

15 

on Climate Change. 74 FR 66496, December 15, 2009. As summarized in the Technical 

Support Document for EPA’s Endangerment and Cause or Contribute Findings under Section 

202(a) of the Clean Air Act, anthropogenic emissions of GHGs are very likely (a 90 to 99 

percent probability) the cause of most of the observed global warming over the last 50 years.10 

Primary GHGs of concern are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), 

hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6). Mobile 

sources emitted 31 percent of all U.S. GHGs in 2007 (transportation sources, which do not 

include certain off-highway sources, account for 28 percent) and have been the fastest-growing 

source of U.S. GHGs since 1990.11 Mobile sources addressed in EPA’s endangerment and 

contribution findings under CAA section 202(a) -- light-duty vehicles, heavy-duty trucks, buses, 

and motorcycles -- accounted for 23 percent of all U.S. GHG emissions in 2007.12 Heavy-duty 

vehicles emit CO2, CH4, N2O, and HFCs and are responsible for nearly 19 percent of all mobile 

source GHGs (nearly 6% of all U.S. GHGs) and about 25 percent of section 202(a) mobile 

source GHGs. For heavy-duty vehicles in 2007, CO2 emissions represented more than 99 

percent of all GHG emissions (including HFCs).13

[INSERT COST and BENEFIT SUMMARY TABLES HERE (annualized MY estimates 

for proposed alternative and comparing with other alternatives by each category. Commenters 

also request that agencies provide a brief clarification on what is included in benefits.] 

 10 U.S. EPA. (2009). “Technical Support Document for Endangerment and Cause or Contribute Findings for 

Greenhouse Gases Under Section 202(a) of the Clean Air Act” Washington, D.C., available at Docket: EPA-HQOAR-2009-0171-11645, and at http://epa.gov/climatechange/endangerment.html. 

11 U.S. Environmental Protection Agency. 2009. Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-

2007. EPA 430-R-09-004. Available at 

http://epa.gov/climatechange/emissions/downloads09/GHG2007entire_report-508.pdf 

12 See Endangerment TSD, Note Error! Bookmark not defined., above, at pp. 180-194. 13 U.S. Environmental Protection Agency. 2009. Inventory of U.S. Greenhouse Gas Emissions and Sinks: See Note 

Error! Bookmark not defined., above.